Golf club heads and methods to manufacture golf club heads
Embodiments of golf club heads and methods to manufacture golf club heads are generally described herein. In one example, a golf club head may have a toe portion, a heel portion, a top portion, a sole portion, a back portion, and a front portion with a face opening. The golf club head may have a face portion joined to the body portion and covering the face opening. The golf club head may include an interior cavity partially, substantially, or entirely filled with a structural adhesive. Other examples and embodiments may be described and claimed.
1. A golf club head comprising:
a body portion comprising a toe portion, a heel portion, a top portion, a sole portion, a front portion, a back portion, a face opening in the front portion, an interior cavity, a filling port accessing the interior cavity from the back portion, and an exhaust port accessing the interior cavity from the back portion;
a face portion joined to the body portion and covering the face opening, the face portion having a front surface and a back surface, the back surface extending from the sole portion to the top portion of the body portion, the face portion coupled to the front portion by a weld extending along a perimeter edge of the back surface of the face portion and along a top perimeter surface, a bottom perimeter surface, and a toe perimeter surface of the body portion;
a first set of ports located in the back portion above a horizontal midplane of the golf club head, the first set of ports comprising at least two ports arranged in a first row along the toe portion, the first set of ports comprising the exhaust port;
a second set of ports located in the back portion below the horizontal midplane, the second set of ports comprising at least three ports arranged in a second row extending from the toe portion to the heel portion, the second set of ports comprising the filling port; and
a structural adhesive disposed in the interior cavity, the structural adhesive bonded to the back surface of the face portion and bonded to a surface of the interior cavity, the structural adhesive having a density of less than 1.2 g/cm 3 and a Shore D hardness greater than 45.
2. A golf club head as defined in claim 1 further comprising a first mass portion sealing the filling port and a second mass portion sealing the exhaust port.
3. A golf club head as defined in claim 1 , wherein the structural adhesive has an overlap shear strength of at least 8.6 MPa at a temperature of 21° C. relative to the back surface of the face portion.
4. A golf club head as defined in claim 1 , wherein the structural adhesive has a Shore D hardness of between and including 48 and 62.
5. A golf club head as defined in claim 1 , wherein the structural adhesive has a thermal coefficient of expansion of between and including 90 and 95.
6. A golf club head as defined in claim 1 , wherein the interior cavity comprises an interior cavity volume, and the structural adhesive occupies at least 75% of the interior cavity volume.
7. A golf club head as defined in claim 1 , wherein a ratio of a structural adhesive volume to a body portion volume is between and including 0.45 and 0.55.
8. A golf club head as defined in claim 1 , wherein the structural adhesive is an epoxy adhesive formed by mixing liquid reactive polymers comprising a base material and a mercaptan-based accelerator material.
9. A golf club head as defined in claim 1 , wherein the structural adhesive has a coefficient of restitution of between and including 0.793 and 0.877 relative to a golf ball.
10. A golf club head comprising:
a body portion comprising a toe portion, a heel portion, a top portion, a sole portion, a front portion, a back portion, a face opening in the front portion, an interior cavity, a filling port accessing the interior cavity from the back portion, and an exhaust port accessing the interior cavity from the back portion;
a face portion joined to the body portion and covering the face opening, the face portion having a front surface and a back surface, the back surface extending from the sole portion to the top portion of the body portion, the face portion coupled to the front portion by a weld extending along a perimeter edge of the back surface of the face portion and along a top perimeter surface, a bottom perimeter surface, and a toe perimeter surface of the body portion;
a first set of ports located in the back portion above a horizontal midplane of the golf club head, the first set of ports comprising at least two ports arranged in a first row along the toe portion, the first set of ports comprising the exhaust port;
a second set of ports located in the back portion below the horizontal midplane, the second set of ports comprising at least three ports arranged in a second row extending from the toe portion to the heel portion, the second set of ports comprising the filling port; and
a structural adhesive disposed in the interior cavity, the structural adhesive bonded to the back surface of the face portion and bonded to a surface of the interior cavity,
wherein the golf club head has a first COR (COR A ) at a first point on a front surface of the face portion and a second COR (COR B ) at a second point on the front surface of the face portion, and wherein a percent difference between the first COR and the second COR is less than 0.5%, the first point coinciding with a sweet spot on the front surface of the face portion and the second point located at least 8 millimeters from the first point.
11. A golf club head as defined in claim 10 , wherein the structural adhesive has a density of less than 1.2 g/cm 3 and a Shore D hardness greater than 45.
12. A golf club head as defined in claim 10 , wherein the structural adhesive has an overlap shear strength of at least 8.6 MPa at a temperature of 21° C. relative to the surface of the interior cavity.
13. A golf club head as defined in claim 10 , wherein the structural adhesive has a thermal coefficient of expansion between and including 90 and 95.
14. A golf club head as defined in claim 10 , wherein the interior cavity comprises an interior cavity volume and the structural adhesive occupies at least 85% of the interior cavity volume.
15. A golf club head as defined in claim 10 , wherein a ratio of a structural adhesive volume to a body portion volume is greater than 0.2.
16. A golf club head as defined in claim 10 , wherein the structural adhesive is an epoxy adhesive formed by mixing liquid reactive polymers comprising a base material and a mercaptan-based accelerator material.
17. A golf club head as defined in claim 10 , wherein the structural adhesive has a coefficient of restitution of between and including 0.751 and 0.919 relative to a golf ball.
18. A golf club head as defined in claim 10 , wherein the percent difference between the first COR and the second COR is less than 0.25%.
19. A golf club head comprising:
a body portion comprising a toe portion, a heel portion, a top portion, a sole portion, a front portion, a back portion, a face opening in the front portion, an interior cavity, a filling port accessing the interior cavity from the back portion, and an exhaust port accessing the interior cavity from the back portion;
a face portion joined to the body portion and covering the face opening, the face portion having a front surface and a back surface, the back surface extending from the sole portion to the top portion of the body portion, the face portion coupled to the front portion by a weld extending along a perimeter edge of the back surface of the face portion and along a top perimeter surface, a bottom perimeter surface, and a toe perimeter surface of the body portion;
a first set of ports located in the back portion above a horizontal midplane of the golf club head, the first set of ports comprising at least two ports arranged in a first row along the toe portion, the first set of ports comprising the exhaust port;
a second set of ports located in the back portion below the horizontal midplane, the second set of ports comprising at least three ports arranged in a second row extending from the toe portion to the heel portion, the second set of ports comprising the filling port;
a structural adhesive disposed in the interior cavity, the structural adhesive bonded to the back surface of the face portion and bonded to a surface of the interior cavity of the body portion, the structural adhesive having a density of less than 1.2 g/cm 3 and a Shore D hardness greater than 45;
a first mass portion sealing the filling port; and
a second mass portion sealing the exhaust port.
20. A golf club head as defined in claim 19 , wherein the interior cavity has a maximum front-to-rear depth located below the horizontal midplane and above the filling port.