JP5315577B2 - Iron golf club head and iron golf club - Google Patents

Description

  The present invention relates to an iron golf club head and an iron golf club, and more particularly to an iron golf club head having a cavity portion on the back side and an iron golf club having the iron golf club head.

2. Description of the Related Art Conventionally, a cavity back type iron golf club head having a cavity portion on the back side of a face portion has been widely known. This type of golf club head is described in, for example, Japanese Patent Application Laid-Open No. 2000-126337 and Japanese Patent Application Laid-Open No. 11-178960 (Japanese Patent No. 3476354).
JP 2000-126337 A JP 11-178960 A (Patent No. 3476354)

  In the iron golf club head described in Japanese Patent Application Laid-Open No. 2000-126337, a thick portion is formed in the cavity corresponding to the sweet spot of the head to reinforce the hitting surface.

  However, as with the iron golf club head described in the above-mentioned document, the function of supporting the ball striking surface from the rear cannot be obtained by simply forming a thick portion in the cavity. Therefore, the effect of reinforcing the hitting surface is not sufficient, and a so-called solid hit feeling cannot be obtained sufficiently.

  On the other hand, in the iron golf club head described in JP-A-11-178960, a thick portion is formed on the face back surface. However, even in the case of the iron golf club head described in this document, the function of supporting the ball striking surface from the rear cannot be obtained as in the case of Japanese Patent Application Laid-Open No. 2000-126337. Therefore, after all, a solid feel at impact cannot be obtained sufficiently.

  The present invention has been made to solve the above problems, and provides an iron golf club head capable of realizing a solid feel at impact and an iron golf club provided with the iron golf club head. The purpose is to do.

An iron golf club head according to the present invention includes a face portion having a ball striking surface, a face back portion located on the back side of the face portion, a toe portion and a heel portion, and a rear side of the face back portion. A cavity portion provided on the bottom surface with a groove portion extending in a direction from the portion toward the heel portion, and a rear wall portion positioned rearward of the groove portion and defining a rear end portion of the groove portion and a part of the bottom portion of the cavity portion, A rib is provided on the bottom surface of the groove portion so as to be convex and connects the face back portion and the rear wall portion so as to be integrated, and extends in the front-rear direction.

  A convex portion may be formed on the bottom surface of the groove portion by changing the depth of the groove portion in a direction from the toe portion toward the heel portion, and the rib may be configured by the convex portion. Moreover, you may provide a rib in the groove part located in the back side of a sweet spot. The upper surface of the rib may be disposed at a position lower than the upper surface of the rear wall portion, or may be disposed at a position higher than the height of the upper surface of the rear wall portion. Further, the width in the direction from the toe portion of the rib toward the heel portion may be gradually increased from the upper surface of the rib toward the bottom surface of the groove portion.

  An iron golf club according to the present invention includes the above-described iron golf club head.

  Since the iron golf club head of the present invention includes a rib extending in the front-rear direction so as to connect the face back portion and the rear wall portion, the face portion can be supported from the rear by the rib, and a solid shot feeling can be obtained. Can be realized.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
(Embodiment 1)
FIG. 1 is a partial perspective view of an iron golf club 1 according to Embodiment 1 of the present invention. The iron golf club 1 is number 3. As shown in FIG. 1, an iron golf club 1 includes a head (iron golf club head) 2, a shaft 3, and a grip (not shown). As the shaft 3 and the grip, a known configuration can be adopted.

  The head 2 is typically mainly composed of a metal such as stainless steel or soft iron, and can be manufactured by forging. The head 2 can be manufactured by combining two or more kinds of metals, but the head 2 can also be manufactured by combining a metal and a non-metal.

  The head 2 includes a face portion having a hitting surface, a face back portion 4 located on the back side of the face portion, a toe portion 10, a heel portion 11, a top edge portion 12, a sole portion 9, and a back side. A cavity portion 13 and a rear wall portion 7 are provided.

  3 to 5 are a sectional view taken along line III-III in FIG. 1, a sectional view taken along line IV-IV in FIG. 1, and a sectional view taken along line VV in FIG. As shown in FIGS. 3 to 5, the face back portion 4 constitutes a back side portion of the face portion 8, a concave portion on the top edge portion 12 side, and an inclined surface on the lower side (sole portion 9 side) of the concave portion. And have.

  Referring to FIG. 1 again, the cavity portion 13 has a groove portion 5 that is positioned rearward of the face back portion 4 and extends in the toe-heel direction from the toe portion 10 toward the heel portion 11. As shown in FIG. 2, the groove portion 5 has a substantially rectangular shape when viewed from the top edge portion 12 side (above). In the first embodiment, the groove portion 5 is provided so as to be along substantially the whole of the face back portion 4 in the toe-heel direction, but is provided at least behind the center portion of the face back portion 4 in the toe-heel direction. It only has to be done. The length of the groove portion 5 in the toe-heel direction is, for example, about 50 mm to 60 mm, and the width of the groove portion 5 in the face-back direction, which is the front-rear direction, is, for example, about 5 mm to 10 mm, preferably about 5 mm to 8 mm. Therefore, the length of the groove 5 in the toe-heel direction is longer than the width of the groove 5 in the face-back direction.

  As shown in FIG. 2, the corners of the groove 5 are rounded. By rounding the corners of the groove part 5 in this way, the degree of stress concentration in the vicinity of the corner part of the groove part 5 at the time of hitting can be reduced. Further, the thickness of the face portion 8 in the vicinity of the corner portion of the groove portion 5 can be increased. Thereby, the durability of the head 2 can be improved.

  In the cross section shown in FIGS. 3 to 5, the groove portion 5 extends in the depth direction from the top edge portion 12 toward the sole portion 9 along the face surface (ball striking surface). The depth of the groove 5 changes in the toe-heel direction. In the example shown in FIGS. 1 to 5, the maximum depth of the groove portion 5 is about 9 mm, and the depth of the shallowest portion in the groove portion 5 is about 2 mm to 3 mm. As shown in FIG. 1 and FIG. 2, in the first embodiment, deep portions in the groove 5 are provided at two locations in the toe-heel direction. More specifically, the depth of the groove portion 5 is the shallowest at the central portion in the toe-heel direction and deeper on both sides thereof. In this way, by changing the depth of the groove portion 5 in the toe-heel direction, a convex portion is formed on the bottom surface of the groove portion 5 located in the center portion (behind the sweet spot) in the toe-heel direction. Thus, the rib 6 is formed. That is, the rib 6 is provided in the groove part 5 by locally raising the bottom face of the groove part 5.

  As shown in FIGS. 2 and 4, the rib 6 extends in the front-rear direction so as to connect the face back portion 4 and the rear wall portion 7. As shown in FIG. 4, the height of the rib 6 is set so as to reach a portion (for example, a portion of about 15 mm from the ground) that is considered to hit the ball generally at the face portion 8. In the example of FIG. 4, the upper surface of the rib 6 is disposed at a position lower than the upper surface of the rear wall portion 7.

  By providing the rib 6 as described above, the face portion 8 can be supported from behind by the rib 6 at the time of hitting, and a solid shot feeling can be obtained. Further, by providing the rib 6, mass can be secured on the lower side of the head 2, and the center of gravity of the head 2 can be deepened without increasing the width W in the front-rear direction of the sole portion 9 (see FIG. 3). can do.

  As shown in FIGS. 3 and 5, the rear wall portion 7 is located rearward of the groove portion 5 and is provided so as to rise upward (from the top edge portion 12 side) from the rear end portion of the sole portion 9. The wall surface on the front side of the rear wall portion 7 defines the rear side end portion of the groove portion 5. Further, the upper surface of the rear wall portion 7 defines a part of the bottom portion of the cavity portion 13.

  6 to 8 are cross-sectional views of the head 2 of a 7-iron golf club. In the case of this head 2, the maximum depth of the groove 5 is about 6 mm, and the depth of the shallowest portion in the groove 5 (depth of the portion where the rib 6 is formed) is about 1 to 2 mm. Other configurations are basically the same as those shown in FIGS.

  FIG. 9 shows an example of the structure of the head 2 viewed from the back side. As shown in FIG. 9, the upper surface of the rib 6 is disposed at a position lower than the upper surface 7 a of the rear wall portion 7. Further, the bottom surface of the groove portion 5 is formed by a corrugated curved surface. The upper surface of the rib 6 is constituted by a part of the corrugated curved surface.

  The width of the rib 6 in the toe-heel direction gradually increases from the top surface of the rib 6 toward the bottom surface of the groove portion 5. By making the shape of the rib 6 in this way, the effective bending length of the face portion can be appropriately changed in the toe-heel direction.

  Here, the “effective deflection length” is the length in the vertical direction (direction from the sole portion 9 toward the top edge portion 12) of a portion that is considered to be mainly bent and deformed in the face portion when the ball is hit by the face portion. Say it. In the example of FIG. 9, the effective deflection length (the length from the bottom surface of the groove 5 to the vicinity of the top edge portion 12) of the face portion located on both sides of the rib 6 can be secured long. Even in the case of an offset impact that deviates from the spot in the toe-heel direction, the face portion can be appropriately bent, and the degree of decrease in flight distance can be reduced. Further, the “effective deflection length” can be increased as the distance from the rib 6 in the toe-heel direction increases. Furthermore, by changing the width of the rib 6 in the toe-heel direction as described above, it is possible to contribute to deepening the position of the center of gravity of the head 2.

  The maximum depths of the groove portions 5 located on both sides of the rib 6 may be equal, or may be different. For example, it is conceivable that the maximum depth of the groove portion 5 located on the heel portion 11 side is made deeper than the maximum depth of the groove portion 5 located on the toe portion 10 side. Thereby, the effective bending length of the face part located in the heel part 11 side can be ensured easily.

  In the example of FIG. 9, the shape of the bottom surface of the groove portion 5 located on both sides of the rib 6 is a shape curved in a substantially arc shape, but the bottom surface shape can be arbitrarily selected. Moreover, when the bottom face shape of the groove part 5 is a substantially circular arc shape, it is possible that the curvature radius of the bottom face of the groove part 5 shall be about 10 mm-15 mm, for example. The above-mentioned “effective deflection length” can also be controlled by the curvature radius of the bottom surface of the groove portion 5.

  Next, the inventor of the present application provides an iron golf club 1 (the product of the present invention) having the head 2 shown in FIGS. 1 to 5 and a groove continuous from the toe portion to the heel portion in the sole portion in the same manner as the product of the present invention. However, the degree of reduction in the coefficient of restitution at the time of offset impact was compared with a conventional product that does not have a convex portion that connects the rear face of the face and the rear wall, and the result will be described with reference to FIG.

  The coefficient of restitution is determined by making a golf ball (mass: m) collide with a stationary golf club head (mass: M), the incident speed of the ball (velocity of the ball before colliding with the face surface) VIN, and the reflection velocity (face surface). The velocity of the ball after the collision with V) is measured and is calculated from the following formula (1).

VOUT / VIN = (eM−m) / (M + m) (1)
In addition, as a golf ball, a pinnacle gold LS sold from ACUSHNET COMPANY was stored in a room at about 23 ° C., and the collision speed was set to 40.5 m / s. Further, when the golf ball collided with the face surface, the club head was fixed so that the ball collided from the normal direction of the face surface in order to realize rebound to the front. The measurement was repeated 7 times, and was calculated by averaging 5 times with the upper and lower values cut.

  As a result, as shown in FIG. 16, in the present invention product, the restitution coefficient (flight distance) at the time of offset hitting at a position 15 mm away from the heel side is the restitution coefficient at the time of hitting at the sweet spot position (center). Whereas it is 99.9%, with the conventional product, the coefficient of restitution at the time of offset hitting at a position 15 mm away from the heel side is 98.0% of the coefficient of restitution at the time of hitting at the sweet spot position (center). In addition, the product of the present invention had a lower degree of reduction in the coefficient of restitution (flight distance) at the time of offset hitting. Similarly, in the case of offset impact at a position 15 mm away from the toe side, the product of the present invention has a lower degree of reduction in the coefficient of restitution (flight distance) during offset impact than the conventional product. From this result, it can be said that by using the product of the present invention, it is possible to suppress a decrease in flight distance during offset hitting.

  Moreover, since this inventor also tested also about the hit feeling, the result is demonstrated using following Table 1. FIG.

  As the product of the present invention, an iron golf club of the type shown in FIG. 1 and having a number of 5 is prepared, and as a conventional product A, S-30V (Mizuno made: cavity type integrally formed by forging) No. 5 iron of an iron golf club head having no groove on the sole part is prepared, and as a conventional product B, MX-23 (Mizuno: a cavity type iron golf club head integrally formed by forging, Like the invention of the present application, a 5th iron is prepared on the sole part, which has a groove that continues from the toe part to the heel part but does not have a convex part that connects the back face and the rear wall part. Ten players (1 to 10) (head speed: 39 to 48 m / s, handicap: 3 to 14) were given test shots, and each club was evaluated for the feel at impact. The evaluation was performed by assigning a score of 1 to 3 to each club, and the lower the score, the better the feel at impact was (solid). In addition, the same evaluation may be given to those who feel that the hit feeling is equivalent. The results are shown in Table 1 below.

As shown in Table 1, it can be seen that most players have judged that the hit feeling of the product of the present invention is better (solid) than the conventional product.
(Embodiment 2)
Next, Embodiment 2 of the present invention and its modification will be described with reference to FIGS. 10-15 is a figure which shows Embodiment 2 of this invention, and its modification.

  As shown in FIG. 10, the upper surface of the rib 6 may be a flat surface. Thereby, the effective deflection length of the face portion on the upper surface of the rib 6 can be made longer than that in the first embodiment, and the rebound characteristics at the center portion of the face are improved while making the shot feeling solid. be able to.

  As shown in FIG. 11, the height of the rib 6 may be lowered and the width of the rib 6 in the toe-heel direction may be increased. In this case, the rebound characteristics at the center of the face can be further improved than in the case of FIG.

  As shown in FIG. 12, the inclination of the side surface of the rib 6 may be steep. In this case, the effective deflection length of the face portions located on both sides of the rib 6 can be increased, and the rebound characteristics at the time of offset hitting can be improved while making the shot feeling solid.

  As shown in FIG. 13, the height of the upper surface of the rib 6 may be equivalent to the height of the upper surface 7 a of the rear wall 7, and the height of the upper surface of the rib 6 as shown in FIGS. 14 and 15. May be made higher than the height of the upper surface 7 a of the rear wall 7. In either case, the feel at impact can be made solid more effectively.

  In the above-described embodiment, the case where the number of the ribs 6 is single is illustrated, but a plurality of ribs 6 may be provided. Also, a plurality of grooves 5 may be provided. For example, a plurality of grooves 5 may be provided side by side in the face-back direction, and ribs 6 may be formed in the grooves 5. Further, as described above, the rib 6 may be integrally formed of the same material as the head 2, but the rib 6 may be formed by fitting another member into the groove portion 5.

  Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a perspective view which shows a part of iron golf club in Embodiment 1 of this invention. It is a top view which shows the head of the iron golf club in Embodiment 1 of this invention. It is sectional drawing seen along the III-III line of FIG. It is sectional drawing seen along the IV-IV line of FIG. It is sectional drawing seen along the VV line of FIG. FIG. 4 is a cross-sectional view of a head of an iron golf club that is different from the iron golf club shown in FIG. 1 and shows a cross-section corresponding to FIG. 3. FIG. 5 is a cross-sectional view of a head of an iron golf club that is different from the iron golf club shown in FIG. 1, and shows a cross-section corresponding to FIG. 4. FIG. 6 is a cross-sectional view of a head of an iron golf club having a number different from that of the iron golf club shown in FIG. 1 and showing a cross-section corresponding to FIG. 5. It is a rear view which shows the head of the iron golf club in Embodiment 1 of this invention. It is a rear view which shows the head of the iron golf club in Embodiment 2 of this invention. It is a rear view which shows the modification of the head of the iron golf club in Embodiment 2 of this invention. It is a rear view which shows the other modification of the head of the iron golf club in Embodiment 2 of this invention. It is a rear view which shows the further another modification of the head of the iron golf club in Embodiment 2 of this invention. It is a rear view which shows the further another modification of the head of the iron golf club in Embodiment 2 of this invention. It is a rear view which shows the further another modification of the head of the iron golf club in Embodiment 2 of this invention. It is a figure which shows the result of the flight distance test done about this invention product and the conventional product.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Iron golf club, 2 heads, 3 shafts, 4 face back parts, 5 groove parts, 6 ribs, 7 back wall parts, 7a upper surface, 8 face parts, 9 sole parts, 10 toe parts, 11 heel parts, 12 top edge parts 13 Cavity part.

Claims (5)

A face portion (8) having a ball striking surface;
A face back portion (4) located on the back side of the face portion;
A toe part (10) and a heel part (11);
A cavity portion (13) provided on the bottom surface with a groove portion (5) provided on the rear side of the face back portion (4) and extending in a direction from the toe portion (10) toward the heel portion (11);
A rear wall portion (7) located on the rear side of the groove portion (5) and defining a rear side end portion of the groove portion (5) and a part of a bottom portion of the cavity portion (13);
A rib (6) provided in a convex shape on the bottom surface of the groove portion (5), connecting the face back portion (4) and the rear wall portion (7) so as to be integrated, and extending in the front-rear direction; equipped with a,
A convex portion is formed on the bottom surface of the groove portion (5) by changing the depth of the groove portion (5) in a direction from the toe portion (10) toward the heel portion (11), and the rib is formed by the convex portion. (6)
An iron golf club head , wherein the rib (6) is provided in the groove (5) located on the rear side of the sweet spot . Top surface, the was placed in a position lower than the upper surface (7a) of the rear wall (7), an iron golf club head according to claim 1 of the rib (6). The iron golf club head according to claim 1 or 2 , wherein an upper surface of the rib (6) is disposed at a position higher than a height of an upper surface (7a) of the rear wall (7). The width of the rib (6) in the direction from the toe portion (10) to the heel portion (11) becomes wider from the upper surface of the rib (6) toward the bottom surface of the groove portion (5). The iron golf club head according to claim 3 . An iron golf club comprising the iron golf club head according to any one of claims 1 to 4 .

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