JP3111162B2 - Iron club head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an iron club head for a golf club.

[0002]

2. Description of the Related Art Conventionally, as an iron club head in which the center of gravity of the head is lowered to make it easier to make a score in golf play, the ball is easily lifted even when hit with a slightly lower hitting surface. A metal member having a high specific gravity is provided at the bottom, and a metal member having a high specific gravity is provided at the bottom, and a metal member having a high specific gravity is provided at the bottom. An iron club head made of two types of metal members, such as one formed of a low specific gravity metal such as an aluminum alloy or a titanium alloy, is known.

[0003]

However, in the conventional iron club head as described above, the center of gravity is sufficiently reduced, the size of the sweet area is secured, and the iron club head as the iron club head is used for the following reasons. It has not been possible to realize an iron flab head that has all of the appearance (feeling).

When a metal member having a high specific gravity is provided at the bottom and the remainder is formed of a metal for a general iron club head such as stainless steel or soft iron, the appearance as a general iron club head is obtained. When the ring is provided, the club head itself must be reduced in order to eliminate the increase in weight due to the use of the high specific gravity metal. As a result, the moment of inertia is reduced and the sweet area is reduced.

In the case where a metal member having a high specific gravity is provided at the bottom and the remaining portion is formed of a metal having a low specific gravity such as an aluminum alloy or a titanium alloy, a metal having a low specific gravity is used in order to make the weight equal to that of a conventional head. Since the volume of the remaining part using the metal must be increased, the height of the center of gravity increases, and the effect of using the high specific gravity metal for the bottom part is lost.

Accordingly, the present invention provides an iron club which can achieve an unprecedented lower center of gravity while securing the appearance (feeling), the magnitude of the moment of inertia, and the size of the sweet area of the conventional iron club head. The purpose is to provide a head.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, an iron club head according to the present invention has a specific gravity of a head main body of not less than 4.0 g / cm ^{3 and not} more than 10.0 g / cm ³ , and has a striking surface. the specific gravity of the part 1.7 g / cm ³ or more and 4.0g
/ Cm ³ and the specific gravity at the bottom exceeds 10.0 g / cm ³ and
22.0 g / cm ³ or less. Further, when viewed from the front, a vertical line that forms a mutual angle of (90 ° −lie angle) with the neck axis and passes through the center of gravity and intersects the upper surface of the head is defined as an upper point. The point where the line intersects the lower surface of the head is the lower point, and the length of the line connecting the center of gravity and the lower point is 20% to 45% of the length of the line connecting the upper point and the lower point. It is.

The length of the line connecting the upper point and the lower point is 35
It is preferable to set it to 46 mm. Also, the total volume is 30-40cm
^It is desirable to set it to ³ . Preferably, at least the bottom is formed by sintering powder metal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

FIGS. 1 and 2 show an embodiment of an iron club head according to the present invention. This iron club head comprises a head body 1, a striking surface forming section 2, and a bottom section 3.
It consists of three different metal members.

The head body 1 comprises a head base 7 having a recess 6 on the front surface for fitting the ball striking surface forming section 2 on the front, and a neck 4 for mounting the shaft. Ball striking face forming part 2
Is a plate piece, and the front surface is a face surface 5. Bottom 3
Is fixed to the lower surface of the head body 1.

The specific gravity of the head body 1 is 4.0 g.
/ Cm ³ or more and 10.0 g / cm ³ or less, hitting surface forming part 2
The specific gravity of 1.7 g / cm ³ or more and less than 4.0 g / cm ³ ,
The specific gravity of the bottom 3 over the 10.0 g / cm ³ and a 22.0 g / cm ³ or less. The bottom 3 is formed by sintering powder metal.

The head body 1 has a specific gravity of 4.0 g /
The material is not limited as long as it is a metal of not less than cm ^{3 and not} more than 10.0 g / cm ³ , and examples thereof include titanium, titanium alloy, iron-based metal, and copper-based metal.

The ball striking surface forming portion 2 is made of any metal as long as it has a specific gravity of 1.7 g / cm ³ or more and less than 4.0 g / cm ³ .
For example, aluminum, magnesium, beryllium, lithium, alloys thereof, and the like can be given. Further, in addition to metals, ceramics having a specific gravity of 1.7 g / cm ³ or more and less than 4.0 g / cm ³ may be used.

The bottom 3 has a specific gravity exceeding 10.0 g / cm ³ and
Any material can be used as long as the metal is 22.0 g / cm ³ or less. For example, tungsten, tantalum, lead, molybdenum, gold,
Silver, platinum, hafnium, alloys thereof and the like can be mentioned.

As shown in FIGS. 2 and 3, when viewed from the front, a vertical line M that forms a mutual angle θ between the neck axis N and (90 ° −lie angle θ ′) and passes through the center of gravity G is A point AB intersecting the upper surface is defined as an upper point A, a point intersecting the vertical line M with the lower surface of the head is defined as a lower point B, and a line segment AB connecting the upper point A and the lower point B.
The relative length L _1, of the line segment GB connecting the center of gravity G and the lower point B the length L _2, and 20% to 45%.

Further, the length L ₁ of the segment AB connecting the upper point A and the lower point B, and 35～46Mm. Further, the total volume of the iron club head is set to 30 to 40 cm ³ .

With the above configuration, the iron club head has the same appearance (feeling), the magnitude of the moment of inertia, and the size of the sweet area as those of the conventional general iron club head. As it is
The center of gravity G can be significantly reduced. In other words,
The center of gravity G can be significantly reduced while maintaining the same shape, size and total weight as a conventional general iron club head. Therefore, there is no sense of incongruity in appearance, and it is easy to hit a ball easily and it is extremely easy to hit.

Further, since the bottom 3 is formed by sintering powdered metal, the surface can be finished smoothly in an arbitrary shape as compared with casting. In addition, the dimensional accuracy is increased. In addition, high density and high strength are obtained.

The specific gravity of the head body 1 is 4.0 g / cm.
^If it is less than ³ , the entire head must be enlarged in order to secure the same total weight as a conventional general iron club head. Similarly, if the specific gravity of the ball striking surface forming portion 2 is less than 1.7 g / cm ³ , the entire head must be enlarged, so that the center of gravity becomes high and the ball cannot easily hit.

The specific gravity of the head body 1 is 10.0 g / cm.
If it is larger than ³ , the head will be heavier, so the total head will be smaller, the moment of inertia will be smaller, and the sweet area will be smaller in order to have the same total weight as the conventional general iron club head. Would. Similarly, if the specific gravity of the ball striking surface forming portion 2 is 4.0 g / cm ³ or more, the head becomes heavy, so that the total head is reduced in order to obtain the same total weight as a conventional general iron club head, The moment of inertia becomes small, and the sweet area becomes narrow.

If the specific gravity of the bottom 3 is 10.0 g / cm ³ or less, the center of gravity cannot be sufficiently lowered, and it is difficult to hit a ball. Bottom 3
Is practically unlikely to be greater than 22.0 g / cm ³ .

The length L of a line segment AB connecting the upper point A and the lower point B
_{If 1} is 35 mm or less, the head becomes too small, giving a sense of incongruity in appearance, and is extremely difficult to hit. In addition, the moment of inertia becomes small, and the sweet area becomes narrow, resulting in poor directivity. Also, the length L of the line segment AB
_{When 1} is larger than 46 mm, the head becomes too large, giving a sense of incongruity in appearance, and the position of the center of gravity becomes too high, so that it is difficult to hit the ball.

If the total volume of the head is less than 30 cm ³ , the head becomes small, giving a sense of incongruity in appearance, and is extremely difficult to hit. In addition, the moment of inertia becomes small and the sweet area becomes narrow, resulting in poor directivity. On the other hand, if the total volume is larger than 40 cm ³ , the head becomes too large, giving a sense of incongruity in appearance and extremely difficult to strike.

FIG. 4 is a sectional view of another embodiment, in which a penetrating window 9 is provided in the head basic portion 7 of the head main body 1 from the face 5 side to the back face 8 side. The other configuration is the same as that shown in FIGS. 1 to 3 except that the hitting surface forming portion 2 that forms the face 5 and the back face 8 is fitted into the window portion 9.

According to this structure, the proportion of the volume of the striking surface forming portion 2 having a small specific gravity is increased, so that the weight can be further distributed to the bottom portion 3 and the height of the center of gravity can be further reduced.

FIG. 5 is a sectional view of another embodiment, in which a recess 10 is provided on the bottom surface of the head body 1 and a protrusion 11 is provided on the upper surface of the bottom 3 so that the head body 1 1 recess 10
The projection 11 of the bottom 3 is press-fitted or shrink-fitted. Other configurations are the same as those in FIGS.

According to this structure, since the bottom 3 on the side to be fitted into the head main body 1 is made of a sintered metal, the dimensional accuracy of the bottom 3 can be increased, and press-fitting or shrink-fitting can be performed easily and reliably. it can. Further, the degree of freedom in designing the bottom 3 is increased. Therefore, manufacture becomes easy.

The iron club head of the present invention
It is sufficient that at least the bottom 3 is formed by sintering a powder metal. For example, it is also preferable to form the hitting surface forming portion 2 and the bottom 3 by sintering the powder metal. It is also desirable that the head body 1, the striking surface forming portion 2, and the bottom 3 are formed by sintering powder metal.

[0030]

EXAMPLE Next, a prototype club was prepared and an experiment was conducted.
Specifically, as shown in the following Table 1, an iron club head of an example of the present invention and an iron club head of a comparative example were prepared. The loft angle and lie angle of all iron club heads were set to values corresponding to the loft angle and lie angle of a general 5-iron.

[0031]

[Table 1]

Next, the total weight, volume, and line segment AB of the iron club heads of the embodiment and the comparative example
And the length of the line segment GB, and the percentage of the line segment GB with respect to the line segment AB are shown in Table 2 below.

[0033]

[Table 2]

As is apparent from Tables 1 and 2, the head according to the embodiment of the present invention has a specific gravity of the head main body of 4.0 g / cm ³ or more and 10.0 g / cm ³ or less, and a head striking surface forming portion. Specific gravity of 1.7 g / cm ³ or more and less than 4.0 g / cm ³ , specific gravity at the bottom of more than 10.0 g / cm ³ and 22.0 g / cm ³ or less,
Total volume is 30-40cm ³ , length of line AB is 35-46mm, line A
All of the conditions are satisfied in which the length of the line segment GB with respect to the length of B is 20% to 45%.

Thus, the head of the embodiment is
The size of the entire head (the total volume and the length of the line segment AB) remains the size of the conventional iron club head, and has a lower center of gravity than the conventional iron club head.

The head of the comparative example has a specific gravity of the main body, a specific gravity of the striking surface forming portion, a specific gravity of the bottom portion, a total volume, a length of the line segment AB, and a ratio of the line segment GB to the length of the line segment AB. Two or more numerical values out of the ratio of the length are out of the conditions of the present invention.

More specifically, the head of the comparative example is a conventional iron club head formed of a single piece of stainless steel. Since the head is made of a single material, the center of gravity can be sufficiently reduced with respect to the size of the head. I can't. Specifically, the length of the line segment GB with respect to the length of the line segment AB is 49.7%,
The iron has a high center of gravity.

The comparative example is an iron club head in which the main body portion and the striking surface forming portion are made of an aluminum alloy. Since the specific gravity of the main body portion and the striking surface forming portion is extremely small, the head is large to secure the total weight. It has become bad appearance. The comparative example is an iron club head in which the main body portion and the ball striking surface forming portion are made of stainless steel. Since the specific gravity of the main body portion and the ball striking surface forming portion is large, the entire head has to be reduced in order to have a low center of gravity. , Looks bad.

In the comparative example, since the specific gravity at the bottom is small, the specific gravity cannot be sufficiently reduced, and the line segment G with respect to the length of the line segment AB is not obtained.
The ratio of the length of B is large. Specifically, the length of the line segment GB with respect to the length of the line segment AB is 49.5%, which is a high center of gravity.

In the comparative example, since the specific gravity of the striking surface forming portion is extremely small, the entire head must be enlarged, and the appearance is poor. In the comparative example, since the specific gravity of the main body was extremely large, the entire head had to be reduced.
The appearance is getting worse. In addition, it is a difficult head with a narrow sweet area.

Next, an actual hit test was performed by a person using the iron club heads of the example and the comparative example. A shaft was attached to each head of the example and the comparative example, and a grip was attached to the shaft so that the weight and swing balance of the iron club were all the same.

The subjects are composed of a total of 30 subjects, each of which is a beginner class, an average class, and an advanced class, each of which is 10 people in each category. For the test, each iron club
Ten balls were hit at a time, and the launch angle of the hit ball immediately after the shot was measured and a questionnaire survey of feeling was conducted.

FIG. 6 is a bar graph showing the average launch angle of each iron club in a test of 10 balls. Table 3 shows the results of a questionnaire survey on the feeling of each iron club by trial hitting.

[0044]

[Table 3]

The results of the launch angle measurement of FIG. 6 and the results of the questionnaire survey of Table 3 above are summarized in Table 4 below. The launch angle was evaluated as x when 11 ° or less, Δ when 13 ° or less, and ○ when greater than 13 °. In addition, three or less respondents who answered that the questionnaire was favorable were x, 6
The number of persons or less was evaluated as Δ, and the number of seven or more persons was evaluated as ○.

[0046]

[Table 4]

From the above Table 4, it can be said that the embodiment and the embodiment are all excellent iron clubs (iron club heads) because the launch angle and the questionnaire result in each category are all ○.

In the examples, since the center of gravity could not be slightly lowered, the angle of launching for beginners was low, but in other respects, excellent results were obtained.

In the example, the head was slightly large, giving an impression that the appearance was slightly inferior to middle and advanced players, but the head had a sufficiently low center of gravity, and the hitting ball was easy to rise in each category. Came out.

In the comparative example, a conventional single material head was used, and the appearance was good.
Since it is made of a single metal material, it has a high center of gravity, and the lower the skill, the lower the launch angle.

In the comparative example, since the specific gravity of the main body was small, the entire head was large, the appearance was poor, and the result of the questionnaire was poor. And it has a high center of gravity due to the large size,
First, the launch angle of intermediate players is low.

In the comparative example, since the specific gravity of the ball striking surface forming portion is small, the entire head is downsized. As a result, the center of gravity is low, so that the launch angle is relatively high, but the sweet area is narrow and the head is difficult. Finally, the questionnaire results got worse.

In the comparative example, since the specific gravity at the bottom was small, the center of gravity could not be sufficiently lowered, and the launch angle was low. In the comparative example, since the specific gravity of the ball striking surface forming portion was small, the head was enlarged, and the appearance was poor and the result of the questionnaire was poor. In addition, the height of the center of gravity is also high, and the launch angle of the intermediate level is low for the first time.

In the comparative example, the specific gravity of the main body was large.
Since the head was downsized and the center of gravity was not sufficiently lowered, both the launch angle and the questionnaire results were poor.

[0055]

The present invention has the following remarkable effects by the above-mentioned structure.

According to the iron club head of the first aspect, it is possible to attain a low center of gravity, and at the same time, to have a good appearance and a good feeling. In addition, the sweet area can be made sufficiently large, and the moment of inertia can be made sufficiently large. Accordingly, it is possible to realize an iron club head that is easy for all golfers, from beginners to advanced players, to hit easily and has a high hitting angle (the hitting ball easily rises).

According to the iron club head according to the second aspect, the head is neither too small nor too large, and can have a sufficiently low center of gravity, which makes it easier to strike.

According to the iron club head according to the third aspect, the head is neither too small nor too large, nor too light or too heavy, and can have a sufficiently low center of gravity. Easy to hit.

According to the iron club head of the fourth aspect, the portion formed by sintering the powder metal can be finished in a free shape and a smooth surface as compared with casting. In addition, dimensional accuracy is high, and press-fitting and shrink-fitting are easy, so that it can be easily manufactured. Further, the density can be increased and the strength can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional side view.

FIG. 3 is a front view.

FIG. 4 is a cross-sectional side view of another embodiment.

FIG. 5 is a cross-sectional side view of another embodiment.

FIG. 6 is a graph showing the results of a test hit test.

[Description of Signs] 1 Head main body part 2 Striking surface forming part 3 Bottom part A Upper point B Lower point AB Line segment G Center of gravity L ₁ Length L ₂ Length M Vertical line N Neck axis θ Mutual angle θ 'Lie angle

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshie Takano 1-1-1 Kunyokita, Itami-shi, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works (56) References JP-A-5-123427 (JP) JP-A-7-204301 (JP, A) JP-A-63-79681 (JP, A) JP-A-8-308964 (JP, A) JP-A-8-38658 (JP, A) 1-113082 (JP, A) JP-A-9-24124 (JP, A) JP-A-5-337222 (JP, A) Japanese Utility Model Application Sho 61-139257 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A63B 53/00-53/16

Claims (4)

(57) [Claims] 1. The specific gravity of the head main body 1 is set to 4.0 g / cm ³ or more and 10.0 g / cm ³ or less, and the specific gravity of
1.7 g / cm ³ or more and less than 4.0 g / cm ³ , the specific gravity of the bottom ^{3 is} more than 10.0 g / cm ³ and 22.0 g / cm ³ or less,
Further, when viewed from the front, a vertical line M that forms a mutual angle θ between the neck axis N and (90 ° −lie angle θ ′) and passes through the center of gravity G is:
The point where the vertical line M intersects the lower surface of the head is defined as the lower point B. The upper point A and the lower point B
Preparative to the length L ₁ of the segment AB connecting, iron club head is characterized in that the length L ₂ of the line segment GB connecting the center of gravity G and the lower point B, was 20% to 45%. 2. The iron club head according to claim ₁ , wherein a length L1 of a line segment connecting the upper point A and the lower point B is 35 to 46 mm. 3. The iron club head according to claim 1, wherein the total volume is 30 to 40 cm ³ . 4. The iron club head according to claim 1, wherein at least the bottom portion is formed by sintering powdered metal.