A torsion-resistant badminton racket frame and its preparation method

Abstract

This invention relates to the field of badminton racket technology, and in particular to an anti-torsion racket frame, comprising a head frame and a shaft. The head frame is formed by curing a composite prepreg and has a hollow cavity inside. A reinforcing core is partially or completely disposed within the hollow cavity. The head frame and shaft are fixedly connected. Carbon fiber composite prepreg is preferred as the composite prepreg. This invention also discloses a method for preparing the anti-torsion racket frame. The anti-torsion racket frame and its preparation method obtained by this invention embed a honeycomb-structured reinforcing core at the lower end of the head frame and fill it with foam material. Utilizing the high shear modulus of the honeycomb reinforcing core and the expansion and filling characteristics of the foam material, the torsional stiffness and overall strength of the corresponding area are enhanced without significantly increasing the weight of the head frame.

Description

Technical Field

[0001] This invention relates to the field of badminton racket technology, and in particular to an anti-torsion racket frame and its manufacturing method. Background Technology

[0002] The term "battle racket frame" generally refers to the head frame of a badminton racket. However, with the development of integrated head frame and shaft structures, the term "battle racket frame" also refers to the combination of the head frame and shaft.

[0003] As the competitive level of badminton improves, higher demands are placed on racket performance. High-performance rackets must simultaneously meet the following requirements: the head frame can withstand high string tension (≥28 lbs), possess excellent torsional resistance (the head frame is not easily twisted at the moment of impact), and remain lightweight to improve swing speed. Current technologies largely rely on high-modulus carbon fiber (such as M40J and T800 grade carbon yarn) and complex layered designs to achieve these performance characteristics, but this is costly. Furthermore, traditional hollow head frames lack stiffness in the area between the 5 o'clock and 7 o'clock positions (i.e., the area from the lower part of the head frame to the shaft), making it prone to torsional deformation and stress concentration. Simply increasing the number of carbon fiber layers would significantly increase the head frame weight and reduce controllability. Summary of the Invention

[0004] To address the aforementioned technical deficiencies, this invention provides an anti-torsion badminton racket frame and its manufacturing method, in which a reinforcing core material is embedded inside the head frame to increase its torsional stiffness and overall cavity without significantly increasing the weight of the head frame.

[0005] This invention discloses an anti-torsion badminton racket frame, including a head frame and a shaft. The head frame is formed by curing a composite prepreg and has a hollow cavity inside. A reinforcing core is partially or completely disposed within the hollow cavity. The head frame and the shaft are fixedly connected. Carbon fiber composite prepreg is preferably used as the composite prepreg.

[0006] The reinforcing core is positioned within a 30° range on each side of the racket shaft at the lower end of the head frame.

[0007] The reinforcing core is made of aramid honeycomb core material cut into a three-dimensional shape that matches the hollow cavity inside the head frame.

[0008] The honeycomb-like pores on the reinforcing core are hexagonal in shape, with a side length of 2-5 mm and a wall thickness of 0.03-0.06 mm.

[0009] Foaming material is filled into the honeycomb-shaped pores on the reinforcing core. After the foaming material is heated and cured, it expands in volume and fills the gap between the reinforcing core and the inner wall of the head frame within the reinforcing core area.

[0010] The foaming material is an epoxy resin-based or acrylate-based expandable microsphere foam.

[0011] A method for preparing an anti-torsion badminton racket frame includes the following steps: Step 1: Based on the dimensions of the hollow cavity of the target head frame, cut the aramid honeycomb core material into a three-dimensional shape that matches the corresponding hollow cavity. Step 2: Place the sheet of foamed material on the honeycomb-shaped pore surface of the reinforcing core; Step 3: Wrap a reinforced core containing foamed material with composite prepreg to form a preform; Step 4: Place the preform into the hot press mold of the badminton racket frame, close the mold and heat it to 130-150℃, keep it at that temperature for 30-60 minutes, and let it solidify and set. Step 5: Demolding, after deburring, filling and grinding, drilling and painting, the finished badminton racket frame is completed.

[0012] The present invention provides an anti-torsion badminton racket frame and its preparation method, wherein a honeycomb-structured reinforcing core is embedded in the lower end of the head frame and filled with foam material. By utilizing the high shear modulus of the honeycomb reinforcing core and the expansion and filling characteristics of the foam material, the torsional stiffness and overall strength of the corresponding area are enhanced without significantly increasing the weight of the head frame.

[0013] The specific beneficial effects of this invention are as follows: High torsional strength: Aramid honeycomb core material has extremely high shear modulus. When combined with the head frame yarn to form a honeycomb plate, it increases the compressive strength of the cross section. In particular, it suppresses the torsional deformation of the lower part of the head frame when hitting the ball. After the foam material is filled, the gap between the honeycomb core and the inner wall is eliminated, realizing integrated stress distribution. High tension resistance: The honeycomb core and foam work together to support the inner wall of the carbon fiber, preventing the head frame from concave or collapsing due to high tension, and significantly improving local compressive strength, which can support the current demand for high tension. Lightweight head frame: The reinforcing core material is only placed in a 30° area on both sides of the shaft, while the upper part of the head frame still maintains a lightweight structure and low swing weight, which meets the needs of modern fast offense and defense; Excellent shock absorption: The porous structure composed of aramid honeycomb core material and foam material can effectively absorb high-frequency vibrations and reduce the impact transmission to the arm when hitting the ball. Attached Figure Description

[0014] Figure 1 This is a front view of the structure of Embodiment 1 of the present invention; Figure 2 This is a top view of the structure of Embodiment 1 of the present invention; Figure 3 for Figure 2 Schematic diagram of AA section; Figure 4 This is a structural cross-sectional view of Embodiment 2 of the present invention. Detailed Implementation

[0015] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0016] Example 1:

[0017] like Figures 1-3 As shown, this invention discloses an anti-torsion badminton racket frame, including a head frame 1 and a shaft 2. The head frame 1 is formed by curing a composite prepreg and has a hollow cavity inside. A reinforcing core 3 is partially or completely disposed within the hollow cavity. The head frame 1 and the shaft 2 are fixedly connected. The composite prepreg is preferably a carbon fiber composite prepreg, which is impregnated in epoxy resin.

[0018] Under normal circumstances, the reinforcing core 3 can fill the entire hollow cavity inside the head frame 1. However, to ensure lightweight design and avoid excessively increasing the weight of the head frame 1, it is generally preferable to use the reinforcing core 3 in a localized manner. The placement of the reinforcing core 3 can be selected according to the actual situation. During normal use of the badminton racket frame, the reinforcing core 3 is placed in the parts of the head frame 1 most prone to torsional deformation or insufficient rigidity. The carbon fiber composite prepreg is wrapped around the outside of the reinforcing core 3 and is integrated with the reinforcing core 3 during the curing process of the carbon fiber composite prepreg.

[0019] The reinforcing core 3 is disposed within a 30° range on each side of the shaft 2 at the lower end of the head frame 1. In normal use, the existing badminton racket frame lacks sufficient rigidity in the area between the 5 o'clock and 7 o'clock positions, making it prone to torsional deformation during impact. Therefore, a reinforcing core 3 is disposed inside the head frame 1 within a 30° range on each side of the shaft 2 to strengthen the rigidity of this area. This effectively enhances the torsional resistance and rigidity of the racket frame during use while minimizing the increase in the weight of the head frame 1, thus improving its performance.

[0020] The reinforcing core 3 is made of aramid honeycomb core material cut into a three-dimensional shape that matches the hollow cavity inside the head frame 1. The reinforcing core 3 is made of aramid honeycomb core material, which is lightweight, has high modulus, high strength, and extremely high toughness. Therefore, the aramid honeycomb core material has high overall strength and toughness, and is extremely lightweight. As a reinforcing core material inside the head frame 1, it does not significantly increase the weight of the head frame 1.

[0021] The honeycomb-like lattice shape on the reinforcing core 3 is regular hexagonal, with a side length of 2-5 mm and a wall thickness of 0.03-0.06 mm. The aramid honeycomb core material's regular hexagonal lattice structure provides better stress stability. While the side length is 2-5 mm (typically 3 mm or 4 mm), the wall thickness is 0.03-0.06 mm (typically 0.04 mm or 0.05 mm). This allows the density of the aramid honeycomb core material to be controlled between 50-130 kg / m³. 3 .

[0022] Foaming material is filled into the honeycomb-shaped pores on the reinforcing core 3. After the foaming material is heated and cured, it expands in volume and fills the gap between the reinforcing core material and the inner wall of the head frame 1 within the range of the reinforcing core material.

[0023] The foaming material is an epoxy resin-based or acrylate-based expandable microsphere foam.

[0024] The foaming material can be selected according to actual needs. After heating and curing, the volume of the foaming material can expand to 20-40 times its original volume. By using the foaming material to fill the pores of the aramid honeycomb core material of the reinforcing core 3 and the gaps between the reinforcing core material and the inner wall of the head frame 1, the overall integrity is strengthened and the force transmission is more stable and reliable.

[0025] In this embodiment, as Figure 3 As shown, the axial direction of the aramid honeycomb core material of the reinforcing core 3 is consistent with the axial direction of the racket shaft 2.

[0026] A method for preparing an anti-torsion badminton racket frame includes the following steps: Step 1: Based on the dimensions of the hollow cavity of the target head frame 1, cut the aramid honeycomb core material into a three-dimensional shape that matches the corresponding hollow cavity. Step 2: Place the sheet of foamed material on the honeycomb-shaped pore surface of the reinforcing core 3; Step 3: Wrap the reinforcing core 3 containing foamed material with composite prepreg to form a preform; of course, the carbon fiber composite prepreg is wrapped on the reinforcing core 3 at a preset angle, such as 0°, ±45°, 90°, etc.

[0027] Step 4: Place the preform into the hot press mold of the badminton racket frame, close the mold and heat it to 130-150℃, keep it at that temperature for 30-60 minutes, and let it solidify and set. The specific temperature and time can be selected according to actual needs, such as keeping it at 130℃ for 60 minutes or at 140℃ for 40 minutes.

[0028] In this process, the foaming material is first heated and expanded, filling and extruding the pores of the honeycomb core material of the reinforcing core 3 and the gaps between the reinforcing core 3 and the carbon fiber composite prepreg. Subsequently, the carbon fiber composite prepreg is cured and shaped.

[0029] Step 5: Demolding, after deburring, filling and grinding, drilling and painting, the finished badminton racket frame is completed.

[0030] Example 2:

[0031] like Figure 4 As shown, the present invention discloses an anti-torsion racket frame, which differs from Embodiment 1 in that the axial direction of the aramid honeycomb core material of the reinforcing core 3 is perpendicular to the axial direction of the racket shaft 2.

[0032] Of course, in other embodiments, the axial direction of the aramid honeycomb core material of the reinforcing core 3 is at a certain angle to the axial direction of the handle 2.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simplification, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A torsion-resistant badminton racket frame, comprising a head frame and a shaft, characterized in that: The head frame is formed by curing composite prepreg and has a hollow cavity inside. A reinforcing core is partially or completely provided in the hollow cavity. The head frame and the racket shaft are fixedly connected.

2. The anti-torsion badminton racket frame according to claim 1, characterized in that: The reinforcing core is positioned within a 30° range on each side of the racket shaft at the lower end of the head frame.

3. A torsion-resistant badminton racket frame according to claim 1 or 2, characterized in that: The reinforcing core is made of aramid honeycomb core material cut into a three-dimensional shape that matches the hollow cavity inside the head frame.

4. The anti-torsion badminton racket frame according to claim 3, characterized in that: The honeycomb-like pores on the reinforcing core are hexagonal in shape, with a side length of 2-5 mm and a wall thickness of 0.03-0.06 mm.

5. The anti-torsion badminton racket frame according to claim 3, characterized in that: Foaming material is filled into the honeycomb-shaped pores on the reinforcing core. After the foaming material is heated and cured, it expands in volume and fills the gap between the reinforcing core and the inner wall of the head frame within the reinforcing core area.

6. The anti-torsion badminton racket frame according to claim 5, characterized in that: The foaming material is an epoxy resin-based or acrylate-based expandable microsphere foam.

7. A method for preparing an anti-torsion badminton racket frame, characterized in that: Includes the following steps, Step 1: Based on the dimensions of the hollow cavity of the target head frame, cut the aramid honeycomb core material into a three-dimensional shape that matches the corresponding hollow cavity. Step 2: Place the sheet of foamed material on the honeycomb-shaped pore surface of the reinforcing core; Step 3: Wrap a reinforced core containing foamed material with composite prepreg to form a preform; Step 4: Place the preform into the hot press mold of the badminton racket frame, close the mold and heat it to 130-150℃, keep it at that temperature for 30-60 minutes, and let it solidify and set. Step 5: Demolding, after deburring, filling and grinding, drilling and painting, the finished badminton racket frame is completed.

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