JP7638313B2 - Racket frame - Google Patents

Description

The present invention relates to a racket frame.

The hitting surface of a racket is formed by stringing the racket vertically and horizontally. For example, in the racket described in Japanese Patent Publication No. 6943608 (Patent Document 1), multiple string insertion passages are formed in the racket frame for inserting the strings, and multiple strings are formed in asymmetric positions on at least one of the vertical and horizontal sides.

Patent No. 6943608

The movement of the string in the in-plane direction of the hitting surface is important to improve spin performance. If the string passed through an insertion passage (through hole) in the racket frame hits the inner surface of the through hole, the movement of the string is restricted. Therefore, it is necessary to prevent the string from hitting the inner surface of the through hole in the racket frame so that the movement of the string is not restricted. With the racket described in the above publication, it is not possible to prevent the string from hitting the inner surface of the through hole in the racket frame. Therefore, as the movement of the string is restricted, spin performance cannot be improved.

The present invention was made in consideration of the above problems, and its purpose is to provide a racket frame that can improve spin performance by preventing the strings from hitting the inner surface of the through-holes of the racket frame.

The racket frame of the present invention includes a grip portion, a shaft portion connected to the grip portion, and a face portion connected to the shaft portion. The face portion, the shaft portion, and the grip portion are arranged side by side in a first direction. The face portion includes an inner peripheral surface, an outer peripheral surface, a tip portion located on the opposite side to the grip portion in the first direction, a rear end portion located on the grip portion side in the first direction, and a side end portion located in a second direction perpendicular to the first direction. The face portion is provided with a plurality of through holes in the circumferential direction of the face portion. Each of the plurality of through holes penetrates the inner peripheral surface and the outer peripheral surface of the face portion. The plurality of through holes includes a first hole and a second hole adjacent to each other. The first hole and the second hole are arranged at least in one of the tip portion, the rear end portion, and the side end portion, and are inclined so that the distance between them becomes closer from the outer peripheral surface toward the inner peripheral surface. The plurality of through holes includes a third hole and a fourth hole adjacent to each other. The third hole is arranged so as to be adjacent to the second hole. The fourth hole is arranged on the opposite side of the third hole from the second hole. The third and fourth holes are located at the tip and are inclined so that the distance between them decreases from the outer circumferential surface to the inner circumferential surface. The first and second holes are located at the tip. The second and third holes are inclined so that the distance between them increases from the outer circumferential surface to the inner circumferential surface.

The present invention improves spin performance by preventing the string from hitting the inner surface of the through-hole in the racket frame.

FIG. 2 is a front view showing a schematic view of a racket frame according to the embodiment. 1 is an enlarged front view showing a schematic view of a racket according to an embodiment; FIG. 3 is an enlarged view showing a portion III in FIG. 2 . FIG. 4 is an enlarged view showing a portion IV in FIG. 3 . 2 is an enlarged perspective view showing a schematic diagram of a positional relationship between a plurality of through holes of a racket frame and strings in the racket of the present embodiment. FIG. FIG. 3 is an enlarged view showing a portion VI in FIG. 2 . FIG. 2 is a front view for explaining a state in which strings are strung on a racket frame of the racket of the present embodiment. FIG. 11 is an enlarged front view showing a schematic positional relationship between a plurality of through holes in a racket frame of a comparative example and strings. FIG. 13 is an enlarged perspective view showing a schematic positional relationship between a plurality of through holes in a racket frame of a comparative example and strings.

The following describes an embodiment of the present invention with reference to the drawings. Unless otherwise specified, the same or corresponding parts in the following drawings are given the same reference symbols and their description will not be repeated.

The structure of the racket frame 10 according to this embodiment will be described with reference to FIG. 1. In the following figures, for ease of explanation, the multiple through holes H are omitted where appropriate. The racket frame 10 according to this embodiment includes a face portion 1, a shaft portion 2, and a grip portion 3. The face portion 1, the shaft portion 2, and the grip portion 3 are arranged side by side in a first direction (vertical direction) D1. The shaft portion 2 is arranged between the face portion 1 and the grip portion 3 in the first direction D1.

The material used for the racket frame 10 is, for example, CFRP (Carbon Fiber Reinforced Plastic). However, the material used for the racket frame 10 is not limited to CFRP. For example, the material used for the racket frame 10 can be GFRP (Glass Fiber Reinforced Plastic) or the like.

The face portion 1 has an elliptical ring shape in plan view. The longitudinal direction of the face portion 1 in plan view is along the first direction D1. The lateral direction of the face portion 1 in plan view is along the second direction (horizontal direction) D2 perpendicular to the first direction D1. The depth direction of the face portion 1 in plan view is along the third direction (thickness direction) D3 perpendicular to the first direction D1 and the second direction D2.

The face portion 1 has a first end (tip) 1a and a second end (rear end) 1b in the first direction D1. The first end 1a is the end of the face portion 1 that is located opposite the grip portion 3 in the first direction D1. The first end 1a is located at the front end of the face portion 1 in the first direction D1. The second end 1b is the end that is located on the grip portion 3 side in the first direction D1. The second end 1b is located at the rear end of the face portion 1 in the first direction D1.

The face portion 1 includes a first end portion (tip portion) 11 having a first end 1a, and a second end portion (rear end portion) 12 having a second end 1b. The first end portion (tip portion) 11 is located on the opposite side to the grip portion 3 in the first direction D1. The first end portion 11 extends along the circumferential direction of the face portion 1 with the first end portion 1a as the center. The second end portion (rear end portion) 12 is located on the grip portion 3 side in the first direction D1. The second end portion 12 extends along the circumferential direction of the face portion 1 with the second end portion 1b as the center. The second end portion 12 is disposed at a distance from the first end portion 11 in the first direction D1. The second end portion 12 is a yoke portion.

The face portion 1 includes a side end portion 13. The side end portion 13 is located in a second direction D2 perpendicular to the first direction D1. The side end portion 13 has a third end portion (left end portion) 13a and a fourth end portion (right end portion) 13b. The third end portion 13a is disposed between the first end portion 11 and the second end portion 12, and connects one end of the first end portion 11 to one end of the second end portion 12. The fourth end portion 13b is disposed between the first end portion 11 and the second end portion 12, and connects the other end of the first end portion 11 to the other end of the second end portion 12. The fourth end portion 13b is disposed at a distance from the third end portion 13a in the second direction D2.

The face portion 1 includes an inner peripheral surface IS and an outer peripheral surface OS. Each of the first end portion 11, the second end portion 12, the third end portion 13a, and the fourth end portion 13b of the face portion 1 has an inner peripheral surface IS and an outer peripheral surface OS. The face portion 1 has a plurality of through holes H in the circumferential direction of the face portion 1. The plurality of through holes H are arranged at intervals in the circumferential direction of the face portion 1.

Each of the multiple through holes H penetrates the inner peripheral surface IS and the outer peripheral surface OS of the face portion 1. Each of the multiple through holes H has an inner surface. The inner surface of each of the multiple through holes H penetrates the inner peripheral surface IS and the outer peripheral surface OS of the face portion 1. The inner end of the inner surface of each of the multiple through holes H is connected to the inner peripheral surface IS of the face portion 1, and the outer end of the inner surface of each of the multiple through holes H is connected to the outer peripheral surface OS of the face portion 1. The multiple through holes H are provided at each of the first end 11, the second end 12, the third end 13a, and the fourth end 13b.

The multiple through holes H at the first end 11 and the multiple through holes H at the second end 12 face each other in the first direction D1. The multiple through holes H at the third end 13a and the multiple through holes H at the fourth end 13b face each other in the second direction D2.

The shaft portion 2 has a first branch member 2A and a second branch member 2B. The grip portion 3 is the portion that is gripped by the user of the racket 100. The grip portion 3 extends along the longitudinal direction of the racket frame 10. The grip portion 3 is located on the second end 12 side of the racket frame 10.

The structure of the racket frame 10 and racket 100 according to this embodiment will be described with reference to Figures 2 to 7.

Referring to Figures 2 and 7, the racket 100 according to this embodiment includes a racket frame 10 and a string 20. The string 20 is strung on the face portion 1 of the racket frame 10. The string 20 is passed through each of the multiple through holes H. The string 20 has multiple main string portions 201, multiple cross string portions 202, and multiple turn-back portions 203.

The material of the string 20 is, for example, polyester, nylon, etc. The diameter of the string 20 is, for example, 1.20 mm or more and 1.30 mm or less. The diameter of the string 20 may be, for example, 1.20 mm, 1.25 mm, 1.30 mm, etc. The tension of the string 20 is, for example, 40 lbs or more and 60 lbs or less. The tension of the string 20 may be, for example, 40 lbs, 50 lbs, 60 lbs, etc.

The multiple main string portions 201 extend along the first direction D1 between each of the multiple through holes H arranged at the first end 11 and each of the multiple through holes H arranged at the second end 12. The multiple cross string portions 202 extend along the second direction D2 between each of the multiple through holes H arranged at the third end 13a and each of the multiple through holes H arranged at the fourth end 13b.

The multiple folded-back portions 203 are positioned outside the multiple through holes H. The multiple folded-back portions 203 are positioned between adjacent through holes H in the circumferential direction of the face portion 1 at each of the first end 11, the second end 12, the third end 13a, and the fourth end 13b. In other words, the string 20 is folded back outside the adjacent through holes H in the circumferential direction of the face portion 1 at each of the first end 11, the second end 12, the third end 13a, and the fourth end 13b.

The multiple through holes H provided in the face portion 1 of the racket frame 10 will be described in detail with reference to Figures 2 to 6.

Referring to Figures 2 and 3, the face portion 1 of the racket frame 10 further includes a grommet 15. The grommet 15 protects the string 20. The material of the grommet 15 is, for example, a thermoplastic resin, a thermosetting resin, or rubber. The material of the grommet 15 may be, for example, a nylon resin. One through hole H is provided in one grommet 15. The minimum width of the hole of the grommet 15 is greater than the width of the string 20.

The multiple through holes H are arranged symmetrically with respect to the center line CL (virtual line) of the face portion 1 passing through the first end 1a and the second end 1b. The center line CL passes through the central axis of the grip portion 3. The multiple through holes H include a first hole H1 and a second hole H2. The first hole H1 and the second hole H2 are arranged at least in one of the first end (tip portion) 11, the second end (rear end portion) 12, and the side end portion 13. In this embodiment, the first hole H1 and the second hole H2 are arranged at all of the first end (tip portion) 11, the second end (rear end portion) 12, and the side end portion 13. The multiple through holes H also include a third hole H3 and a fourth hole H4. The first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 are holes through which the main string portion 201 of the string 20 passes.

The first hole H1, the second hole H2, the third hole H3 and the fourth hole H4, which are arranged at the first end (tip) 11, are arranged in this order so as to be farther away from the center line CL.

Referring to Figures 3 and 4, the first hole H1 and the second hole H2 are adjacent to each other. The first hole H1 is located at a position closest to the center line CL. The second hole H2 is located on the opposite side of the center line CL from the first hole H1. The first hole H1 and the second hole H2 are inclined so that the distance between them decreases from the outer peripheral surface OS toward the inner peripheral surface IS. The center line passing through the center of the first hole H1 and the center line passing through the center of the second hole H2 are inclined in opposite directions relative to the direction along the center line CL of the face portion 1.

The third hole H3 and the fourth hole H4 are adjacent to each other. The third hole H3 is arranged so as to be adjacent to the second hole H2. The third hole H3 is arranged on the opposite side of the second hole H2 from the first hole H1. The fourth hole H4 is arranged on the opposite side of the third hole H3 from the second hole H2. The third hole H3 and the fourth hole H4 are arranged at the first end (tip portion) 11. The third hole H3 and the fourth hole H4 are inclined so that the distance between them becomes closer from the outer peripheral surface OS toward the inner peripheral surface IS. The center line passing through the center of the third hole H3 and the center line passing through the center of the fourth hole H4 are inclined in opposite directions to each other with respect to the direction along the center line CL of the face portion 1.

The absolute value of the angle at which the first hole H1 is inclined relative to the center line CL of the face portion 1 extending along the first direction D1 is less than or equal to the absolute value of the angle at which the second hole H2 is inclined, and the absolute value of the angle at which the third hole H3 is inclined is less than or equal to the absolute value of the angle at which the fourth hole H4 is inclined. Preferably, the absolute value of the angle at which the first hole H1 is inclined relative to the center line CL is less than the absolute value of the angle at which the second hole H2 is inclined, and the absolute value of the angle at which the third hole H3 is inclined is less than the absolute value of the angle at which the fourth hole H4 is inclined.

The inclination angle of each of the first hole H1 and the third hole H3 is, for example, 2° to 4° counterclockwise, and the inclination angle of each of the second hole H2 and the fourth hole H4 is, for example, 3° to 5° clockwise. Preferably, the inclination angle of each of the first hole H1 and the third hole H3 is 3° counterclockwise, and the inclination angle of each of the second hole H2 and the fourth hole H4 is 4° clockwise. In this embodiment, the counterclockwise direction is defined as + (plus) and the clockwise direction is defined as - (minus).

Referring to FIG. 5, the planar shape of each of the multiple through holes H is, for example, circular. That is, in this case, the planar shape of each of the front and back surfaces of the multiple through holes H is circular. Note that the planar shape of the through holes H is not limited to a circular shape, and may be, for example, an X-shape.

The multiple through holes H include a first hole H1, a second hole H2, a third hole H3, and a fourth hole H4, which are arranged at the second end (rear end) 12. The first hole H1, the second hole H2, the third hole H3, and the fourth hole H4, which are arranged at the second end (rear end) 12, are arranged in the same manner as at the first end (tip end) 11.

2 and 6, the multiple through holes H include a first hole H1, a second hole H2, a third hole H3, and a fourth hole H4 arranged at the side end 13. In this embodiment, the first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 are provided at the third end 13a. The first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 may be provided at the fourth end 13b. The first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 are holes through which the cross string portion 202 of the string 20 is passed.

The arrangement of the first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 arranged at the side end 13 will be described. The first hole H1 and the second hole H2 are adjacent to each other. The first hole H1 is arranged at a position closest to the center of the face portion 1 in the first direction D1. The second hole H2 is arranged on the opposite side of the center of the face portion 1 in the first direction D1 with respect to the first hole H1. The first hole H1 and the second hole H2 are inclined so that the distance between them decreases from the outer peripheral surface OS toward the inner peripheral surface IS. The center line passing through the center of the first hole H1 and the center line passing through the center of the second hole H2 are inclined with respect to the direction along the center of the face portion 1 in the first direction D1.

The third hole H3 and the fourth hole H4 are adjacent to each other. The third hole H3 is arranged so as to be adjacent to the fourth hole H4. The third hole H3 is arranged on the opposite side of the second hole H2 from the first hole H1. The fourth hole H4 is arranged on the opposite side of the third hole H3 from the second hole H2. The third hole H3 and the fourth hole H4 are inclined so that the distance between them decreases from the outer peripheral surface OS toward the inner peripheral surface IS. The center line passing through the center of the third hole H3 and the center line passing through the center of the fourth hole H4 are inclined with respect to the direction along the center of the face portion 1 in the first direction D1.

With reference to FIG. 7, the state in which the string 20 is strung on the racket frame 10 of the racket 100 of this embodiment will be described. The state in which the string 20 is strung on the first end (tip end) 11 and the second end (rear end) 12 in the face portion 1 of the racket frame 10 will be described. The multiple turn-up portions 203 of the string 20 include the first turn-up portion 203a, the second turn-up portion 203b, the third turn-up portion 203c, the fourth turn-up portion 203d, and the fifth turn-up portion 203e. The main string portion 201 passing through the first hole H1 and the main string portion 201 passing through the second hole H2 are connected via the first turn-up portion 203a. The main string portion 201 passing through the second hole H2 and the main string portion 201 passing through the third hole H3 are connected via the second turn-up portion 203b. The main string portion 201 passing through the third hole H3 and the main string portion 201 passing through the fourth hole H4 are connected via the third folded portion 203c. The main string portion 201 passing through the fourth hole H4 and the main string portion 201 passing through the through hole H on the outside of the fourth hole H4 are connected via the fourth folded portion 203d. The main string portion 201 passing through the through hole H on the outside of the fourth hole H4 and the main string portion 201 passing through the through hole H on the further outside are connected via the fifth folded portion 203e. Although not shown, the string 20 is also strung on the side end 13 in the same manner. That is, the string 20 is also strung on the third end (left end) 13a and the fourth end (right end) 13b.

In the above, the first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 are arranged on one side of the center line CL. However, the first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 may be arranged symmetrically with respect to the center line CL, with the first hole H1 and the second hole H2 sandwiching the center line CL.

Next, the effects of the embodiment will be explained in comparison with a comparative example.

8 and 9, in the racket frame 10 of the comparative example, the first hole H1, the second hole H2, the third hole H3, and the fourth hole H4 each extend along the center line CL of the face portion 1. Therefore, when the strings 20 are strung to form a hitting surface, the tension of the strings 20 causes the strings 20 to strike the inner peripheral surface IS of the inner surface of each of the first hole H1 and the second hole H2 located on both sides of the folded portion 203.

In the racket frame 10 according to this embodiment, the first hole H1 and the second hole H2 are inclined so that the distance between them decreases from the outer peripheral surface OS toward the inner peripheral surface IS. Therefore, when the first hole H1 and the second hole H2 are located on both sides of the folded-back portion 203, it is possible to prevent the string 20 from hitting the inner peripheral surface IS side of the inner surfaces of the first hole H1 and the second hole H2. Therefore, by preventing the string 20 from hitting the inner surface of the through hole H of the racket frame 10, it is possible to improve spin performance.

The first hole H1 and the second hole H2 are located at least one of the first end (tip portion) 11, the second end (rear end) 12, and the side end 13. The vertical string 20 (main string portion 201) at the first end (tip portion) 11 is close to the impact point and therefore has a large effect on spin performance. Therefore, by arranging the first hole H1 and the second hole H2 at the first end (tip portion) 11, the movement of the string 20 in the in-plane direction of the hitting surface can be ensured, thereby improving spin performance.

In addition, the vertical strings 20 (main string section 201) have a greater effect on spin performance than the horizontal strings 20 (cross string section 202). Therefore, by arranging the first hole H1 and the second hole H2 at the second end (rear end) 12, the movement of the strings 20 in the in-plane direction of the hitting surface is ensured, thereby improving spin performance.

In addition, the horizontal strings 20 (cross string section 202) have a smaller effect on spin performance than the vertical strings 20 (main string section 201), but they do affect spin performance. Therefore, by arranging the first hole H1 and the second hole H2 at the side end 13, the movement of the strings 20 in the in-plane direction of the hitting surface can be ensured, thereby improving spin performance.

In addition, the appearance can be improved by preventing the string 20 from hitting the inner surface of the through hole H of the racket frame 10.

In addition, by preventing the string 20 from hitting the inner surface of the through hole H of the racket frame 10, damage to the grommet 15 and the string 20 can be reduced, thereby improving the durability of the grommet 15 and the string 20.

In the racket frame 10 according to this embodiment, the third hole H3 and the fourth hole H4 are inclined so that the distance between them decreases from the outer peripheral surface OS toward the inner peripheral surface IS. Therefore, when the third hole H3 and the fourth hole H4 are located on both sides of the folded-back portion 203, it is possible to prevent the string 20 from hitting the inner peripheral surface IS side of the inner circumference of the third hole H3 and the fourth hole H4. Therefore, by further preventing the string 20 from hitting the inner surface of the through hole H of the racket frame 10, it is possible to further improve spin performance.

In the racket frame 10 according to this embodiment, the absolute value of the inclination angle of the first hole H1 relative to the center line CL of the face portion 1 extending along the first direction D1 is equal to or less than the absolute value of the inclination angle of the second hole H2, and the absolute value of the inclination angle of the third hole H3 is equal to or less than the absolute value of the inclination angle of the fourth hole H4. The inventors have found that this effectively prevents the string 20 from hitting the inner surface of the through hole H.

In the racket frame 10 according to this embodiment, the absolute value of the angle at which the first hole H1 is inclined relative to the center line CL is smaller than the absolute value of the angle at which the second hole H2 is inclined, and the absolute value of the angle at which the third hole H3 is inclined is smaller than the absolute value of the angle at which the fourth hole H4 is inclined. The inventors have found that this effectively prevents the string 20 from hitting the inner surface of the through hole H.

In the racket frame 10 according to this embodiment, the inclination angle of each of the first hole H1 and the third hole H3 is between 2° and 4° counterclockwise, and the inclination angle of each of the second hole H2 and the fourth hole H4 is between 3° and 5° clockwise. The inventors have found that this effectively prevents the string 20 from hitting the inner surface of the through hole H.

The racket 100 according to this embodiment includes the racket frame 10 and the strings 20 threaded through a number of through holes H. This prevents the strings 20 from hitting the inner surface of the through holes H of the racket frame 10, thereby improving spin performance.

(Example)
Next, examples of the racket frame and racket according to the present embodiment will be described in comparison with comparative examples.

In this example, Examples 1 to 5 were compared with Comparative Examples 1 to 6 to verify the state in which the hitting surface was formed by stringing the strings 20. Examples 1 to 5 have the same structure as the racket frame and racket according to the present embodiment. In Examples 1 to 5, the inclination angle of each of the first and third holes is 2° or more and 4° or less in the counterclockwise direction, and the inclination angle of each of the second and fourth holes is 3° or more and 5° or less in the clockwise direction.

In Comparative Example 1, the inclination angle of each of the first and third holes is 1° counterclockwise, and the inclination angle of each of the second and fourth holes is 1° clockwise. In Comparative Example 2, the inclination angle of each of the first and third holes is 5° counterclockwise, and the inclination angle of each of the second and fourth holes is 5° clockwise. In Comparative Example 3, the inclination angle of each of the first and third holes is 10° counterclockwise, and the inclination angle of each of the second and fourth holes is 10° clockwise.

In Comparative Example 4, the inclination angle of each of the first and third holes is 1° counterclockwise, and the inclination angle of each of the second and fourth holes is 1° clockwise. In Comparative Example 5, the inclination angle of each of the first and third holes is 5° counterclockwise, and the inclination angle of each of the second and fourth holes is 5° clockwise. In Comparative Example 6, the inclination angle of each of the first and third holes is 10° counterclockwise, and the inclination angle of each of the second and fourth holes is 10° clockwise.

In Example 1, the string material is polyester, the string diameter is 1.25mm, and the string tension is 50 lbs. In Example 2, the string material is polyester, the string diameter is 1.25mm, and the string tension is 60 lbs. In Example 3, the string material is polyester, the string diameter is 1.20mm, and the string tension is 50 lbs. In Example 4, the string material is polyester, the string diameter is 1.20mm, and the string tension is 60 lbs. In Example 5, the string material is nylon (multifilament), the string diameter is 1.30mm, and the string tension is 40 lbs.

In Comparative Examples 1-3, the string material is polyester, the string diameter is 1.25 mm, and the string tension is 50 lbs. In Comparative Examples 4-6, the string material is polyester, the string diameter is 1.25 mm, and the string tension is 60 lbs.

In all of Comparative Examples 1 to 6, the strings hit the inner circumference of the first, second, third and fourth holes. In contrast, in all of Examples 1 to 5, the strings did not hit the inner circumference of the first, second, third and fourth holes. Also, in all of Examples 1 to 5, the strings were located near the center of the first, second, third and fourth holes on the side opposite the folded portion.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 Face portion, 2 Shaft portion, 3 Grip portion, 10 Racket frame, 11 First end portion (tip portion), 13 Side end portion, 20 String, 100 Racket, CL Center line, D1 First direction, D2 Second direction, D3 Third direction, H Through hole, H1 First hole, H2 Second hole, H3 Third hole, H4 Fourth hole, IS Inner surface, OS Outer surface.

Claims (4)

A grip portion and
A shaft portion connected to the grip portion;
a face portion connected to the shaft portion,
the face portion, the shaft portion, and the grip portion are arranged side by side in a first direction,
the face portion includes an inner circumferential surface, an outer circumferential surface, a tip portion located on the opposite side to the grip portion in the first direction, a rear end portion located on the grip portion side in the first direction, and a side end portion located in a second direction perpendicular to the first direction,
The face portion is provided with a plurality of through holes in a circumferential direction of the face portion,
each of the plurality of through holes penetrates the inner circumferential surface and the outer circumferential surface of the face portion;
the plurality of through holes include a first hole and a second hole adjacent to each other,
the first hole and the second hole are disposed in at least one of the front end portion, the rear end portion, and the side end portion , and are inclined so that a distance between them decreases from the outer circumferential surface toward the inner circumferential surface,
the plurality of through holes include a third hole and a fourth hole adjacent to each other,
The third hole is disposed adjacent to the second hole,
The fourth hole is disposed on an opposite side of the third hole from the second hole,
the third hole and the fourth hole are disposed at the tip portion and are inclined so that a distance between them decreases from the outer circumferential surface toward the inner circumferential surface,
the first hole and the second hole are disposed in the tip portion,
The second hole and the third hole are inclined so that the distance between them increases from the outer circumferential surface to the inner circumferential surface . 2. The racket frame of claim 1, wherein an absolute value of an angle at which the first hole is inclined relative to a center line of the face portion extending along the first direction is less than or equal to an absolute value of an angle at which the second hole is inclined, and an absolute value of an angle at which the third hole is inclined is less than or equal to an absolute value of an angle at which the fourth hole is inclined. 3. The racket frame of claim 2, wherein an absolute value of an angle at which the first hole is inclined relative to the center line is smaller than an absolute value of an angle at which the second hole is inclined, and an absolute value of an angle at which the third hole is inclined is smaller than an absolute value of an angle at which the fourth hole is inclined. the inclination angle of each of the first hole and the third hole is greater than or equal to 2° and less than or equal to 4° in a counterclockwise direction;
4. The racket frame according to claim 3 , wherein the inclination angle of each of the second hole and the fourth hole is greater than or equal to 3[deg.] and less than or equal to 5[deg.] clockwise.

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