Artificial shuttlecock

Abstract

Embodiments of the present application provide an artificial shuttlecock, comprising a skirt and a head. The skirt comprises a plurality of artificial feathers and at least two supporting coils. Each artificial feather comprises a feather shaft and a feather vane. The feather shaft comprises a calamus portion, a rachis portion, and a branch portion. The feather vane comprises an inner vane, an outer vane, and an adhesive layer. The inner vane and the outer vane are bonded together by means of the adhesive layer, and cover the rachis portion and the branch portion. The calamus portion is provided in the head. The feather shaft is made of unidirectional continuous special fiber reinforced plastic. The feather shaft has a tensile and bending strength greater than 0.8 Gpa, and a tensile and bending modulus greater than 15 Gpa. The calamus portion and the rachis portion have a cross-sectional thickness greater than 0.65 mm, and a cross-sectional bending coefficient greater than 0.09 mm³. The feather vane is made of a low-density, high-strength and high-rigidity foamed plastic sheet. The artificial shuttlecock in the embodiments of the present application has a flight performance and appearance very similar to those of a shuttlecock made from natural feathers, and exhibits better durability.

Description

An artificial shuttlecock TECHNICAL FIELD

[0001] The present application relates to the technical field of sports equipment, and particularly relates to an artificial shuttlecock. BACKGROUND

[0002] The structural shape of the shuttlecock used in modern badminton is uniformly regulated by the International Badminton Federation (BWF), which is composed of an elastic head, 15 or 16 feathers punched into a specific shape and inserted into the back of the head at a certain deflection angle, and a horn-shaped skirt composed of two groups of supporting coils. The quality of the shuttlecock can be measured by three major performance indicators: first, flight performance, second, durability, and third, appearance.

[0003] Since the birth of badminton, it has been loved by people all over the world, and in 1992, it was included in the official competition items of the International Olympic Games. All along, the shuttlecock used in the sport is mostly made of dozens of knife quill feathers from the wings of geese and ducks, which has stable and unique flight performance. However, there are the following shackles in making shuttlecock with natural goose and duck feathers: first, poor consistency, difficult to collect, complex production process of the shuttlecock, and thus high production cost; second, the supply of natural goose and duck feathers is limited and unstable, and the yield of geese and ducks is itself restricted by market demand and affected by factors such as epidemics and environmental protection; third, the durability of the shuttlecock is poor, and one or even more shuttlecocks will be broken after a game. Therefore, with the popularization of badminton and the significant increase in demand, the price of shuttlecock rises, which affects and restricts the further popularization of the sport.

[0004] Therefore, people thought of using artificial materials to make badminton, one is the plastic overall injection molding of the ball skirt of the badminton, although the resistance to playing is improved a lot, but its flight performance is far from the use of goose and duck feather badminton. Another is to use artificial feathers instead of natural goose and duck feathers to make badminton skirt. But this seemingly simple material replacement has encountered many unimaginable difficulties. On the one hand, badminton enthusiasts have formed a specific muscle memory and subconscious reflex through long-term practice and competition based on specific natural goose and duck feather balls, and have developed very delicate hitting experience. The perception of the ball speed and the control of the hitting power to control the landing point accuracy reaches several cm. A simple estimate, such as the ball flying distance is 10 meters, the landing point error should not exceed 10 cm, the accuracy requirement is 1%. As can be seen, in various hitting states, the difference between artificial badminton and high-quality natural badminton should be accurately controlled within 1%. On the other hand, there are too many factors affecting the flight performance of badminton, such as weight, axial and circumferential position of center of gravity, strength, stiffness and resilience of feather stem, support coil and feather leaf, surface shape of feather leaf, deflection angle and wind resistance coefficient, etc. Moreover, these factors are interdependent and difficult to balance. The most difficult is how to achieve the same stiffness and elasticity as natural feathers with the same light weight of natural feathers, and have higher strength and impact resistance, tear resistance and fatigue resistance.

[0005] The existing artificial badminton, the ball skirt is heavy, the center of gravity is offset to the feather leaf end, resulting in a decrease in the moment of resistance of the ball skirt when the badminton is hit and turned over, a large and long swing of the badminton, and even a rolling, especially affecting the stability of the small ball in front of the net and the flight trajectory of the high ball. The closer to the top end of the badminton skirt, the greater the impact of the overweight, because the force arm at this position is the longest and the moment is the largest. The feather stem and the feather leaf are soft, and the rigidity and resilience of the two are insufficient, resulting in a small reaction force of the ball skirt when the badminton is hit by the racket, and the force acting on the whole ball mainly comes from the ball head. The stress point on the net line is concentrated, the action time is short, and the player will feel that the ball is heavy and the impact is large, and the net line is easy to be broken, like playing a plastic badminton with a soft ball skirt. Secondly, the ball skirt is soft, which is retracted under the action of high-speed wind resistance, resulting in a decrease in resistance, a fast flight speed, and a slow ball speed decay. In addition, the feather leaf is deformed after being hit and does not have the structure of natural feather silk, which cannot quickly return to position after deformation and restore the normal deflection angle sequence, that is, the so-called "reverse hair" state, affecting the subsequent stable flight. The service life is short, and the bending strength, shear strength, tear strength, impact strength and corresponding fatigue strength of the feather stem and the feather leaf are poor. SUMMARY

[0006] To solve the above problems, the present patent application provides an artificial badminton with similar appearance to natural badminton, light and strong rigidity of the ball skirt, good flight performance and long service life.

[0007] The present application provides an artificial shuttlecock, comprising:

[0008] a skirt and a head, wherein the skirt comprises a plurality of artificial feathers and at least two supporting loops, the artificial feather comprises a feather stem and a feather leaf, the feather stem comprises a feather root, a feather shaft and a feather branch, the feather leaf comprises an inner feather leaf, an outer feather leaf and an intermediate bonding layer;

[0009] the inner feather leaf and the outer feather leaf are bonded together by the intermediate bonding layer and cover the feather shaft and the feather branch, the feather root is arranged in the head, and the supporting loop fixes the feather shaft;

[0010] the feather stem is made of unidirectional continuous fiber reinforced composite plastic, the longitudinal tensile and bending strength of the feather stem is higher than 0.8 Gpa, the longitudinal tensile and bending modulus of the feather stem is higher than 15 Gpa, the cross-sectional thickness of the feather root and the feather shaft is greater than 0.65 mm, and the cross-sectional bending coefficient is greater than 0.09 mm³;

[0011] the feather leaf is made of low-density high-strength high-rigidity foamed plastic sheet.

[0012] In some embodiments, the thickness of the feather branch decreases in the direction towards the top of the feather leaf.

[0013] In some embodiments, the cross section of the feather stem is square or rectangular, and the cross-sectional bending coefficient of the longitudinal middle position of the feather branch is 0.5-0.7 times that of the cross-sectional bending coefficient of the bottom of the feather branch.

[0014] In some embodiments, the sum of the weight of the head of the feather leaf and the feather branch is between 40-75 mg, and the center of gravity of the artificial shuttlecock is located at a position 3-7 mm away from the head along the axis of the skirt.

[0015] In some embodiments, the unidirectional continuous fiber reinforced composite plastic is directly compounded or modified compounded by one or more high-strength and high-modulus special continuous fibers and resin materials, and the special continuous fibers include carbon fibers, glass fibers, aramid fibers and ultra-high molecular weight polyethylene fibers.

[0016] In some embodiments, the modified compounding refers to adding materials that can reduce density or increase toughness in the resin matrix before or during compounding, including hollow glass microbeads, foamed plastic microspheres, and / or physical or chemical foaming agents and toughening agents.

[0017] In some embodiments, the feather stem is made of unidirectional continuous fiber reinforced plastic by pultrusion or laminated compounding of one or more high-strength and high-modulus special fibers and resin.

[0018] In some embodiments, the outer vane and the inner vane are respectively selected from the same or different two of foamed or microcellular foamed polyethylene EPE, polypropylene EPP, and polystyrene EPS bubble film.

[0019] In some embodiments, the intermediate adhesive layer is a single-layer or double-layer elastic hot melt adhesive film or hot melt adhesive non-woven fabric adhesive film with a thickness of 5-25 um.

[0020] In some embodiments, the back of the ball head is provided with a number of circumferentially distributed inclined holes equal to the number of artificial feathers on the ball skirt, and glue is injected into the inclined holes, or the artificial feathers are inserted into the inclined holes after being glued at the feather portion, and then the intersection between the feather portion and the back of the ball head is glued to reinforce.

[0021] In some embodiments, the vane portions of adjacent artificial feathers on the ball skirt overlap each other, and the middle portion of the vane portion on the inner side is provided with a continuous or intermittent cutting line with a total length of 5-20 mm close to and along the shaft.

[0022] The artificial feather ball according to the embodiments of the present application has substantially the same quality and quality distribution, rigidity and elasticity as natural high-quality goose and duck feathers, and has the same flight performance, higher bending strength, and impact resistance, shear resistance, tear resistance and fatigue resistance, excellent resistance to playing, and can be mass-produced at a moderate cost.

[0023] It should be understood that the content described in the summary section is not intended to limit the key or important features of the embodiments of the present application, nor to limit the scope of the present application. Other features of the present application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and other features, advantages and aspects of the embodiments of the present application will become more apparent by describing in detail the following embodiments with reference to the attached drawings. The attached drawings are intended to better understand the present application and do not limit the present application. In the drawings, the same or similar reference numerals refer to the same or similar elements, and:

[0025] FIG. 1 shows a schematic diagram of the overall structure of an artificial feather ball according to an embodiment of the present application;

[0026] FIG. 2 shows a front view of an artificial feather ball according to an embodiment of the present application;

[0027] FIG. 3 shows a side split view of an artificial feather according to an embodiment of the present application;

[0028] FIG. 4 shows a schematic diagram of the structure of a shaft according to an embodiment of the present application;

[0029] Fig. 5 shows a schematic diagram of the cross-sectional structure of the head of the artificial shuttlecock according to an embodiment of the present application;

[0030] Fig. 6 shows a schematic diagram of the structure of the head of the artificial shuttlecock from the perspective of the skirt according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0032] In addition, the term "and / or" herein merely describes an association relationship of associated objects, and indicates that there can be three relationships, for example, A and / or B can represent the three cases of A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0033] The technical solutions of the present application will be described below in conjunction with specific embodiments.

[0034] The artificial shuttlecock of the embodiments of the present application is obtained by innovative material selection, structure design and production process, and has basically the same quality and quality distribution, rigidity and elasticity as natural high-quality goose and duck feathers, so as to obtain the same flight performance, and has higher bending strength and impact resistance, shear resistance, tear resistance and fatigue resistance, thereby obtaining excellent playing resistance, and can be mass-produced at a proper cost.

[0035] Specifically, as shown in Fig. 1, it is a schematic diagram of the overall structure of the artificial shuttlecock according to an embodiment of the present application, wherein A is the axial line of the shuttlecock, and G is the position of the center of gravity of the shuttlecock. Fig. 2 shows a front view of the artificial feather of the artificial shuttlecock according to an embodiment of the present application; Fig. 3 shows a side split view of the artificial feather according to an embodiment of the present application; Fig. 4 shows a schematic diagram of the structure of the quill according to an embodiment of the present application, wherein W is the width of the cross section of the quill, i.e. the size of the cross section in the vane plane, and T is the thickness of the cross section, i.e. the size perpendicular to the width direction. Fig. 5 shows a schematic diagram of the cross-sectional structure of the head of the artificial shuttlecock according to an embodiment of the present application; Fig. 6 shows a schematic diagram of the structure of the head of the artificial shuttlecock from the perspective of the skirt according to an embodiment of the present application, wherein C is the deflection angle between the vanes of adjacent feathers.

[0036] The artificial shuttlecock 2 of the present embodiment comprises a skirt 3 and a head 4, wherein the skirt 3 comprises a plurality of artificial feathers 1 and at least two supporting loops 5, the artificial feather 1 comprises a feather stem 6 and a feather leaf 7, the feather stem 6 comprises a feather root 6c, a feather stem 6b and a feather branch 6a, the feather leaf 7 comprises an inner layer of feather leaf 7b, an outer layer of feather leaf 7a and a bonding layer 7c. One side of the feather leaf 7 is also provided with a continuous or intermittent cutting line 7d.

[0037] The length of the feather stem 6 is 73-78mm, which is divided into a feather root 6c fixedly connected with the head, a feather stem 6b fixedly connected with the supporting loop, and a feather branch 6a fixedly connected with the head of the feather leaf 7, and the length of each part is 11-15mm, 20-25mm and 35-40mm respectively.

[0038] The inner feather leaf 7b and the outer feather leaf 7a are bonded together by the bonding layer 7c, and the feather stem 6b and the feather branch 6a are covered; the supporting loop 5 fixes the feather stem 6b, and the feather root 6c is arranged in the head 4.

[0039] In some embodiments, the feather leaf is made of a white high-elasticity high-rigidity tear-resistant shear-resistant impact-resistant fatigue-resistant and bending-resistant low-density foamed plastic sheet, which is cut according to the shape of a natural shuttlecock leaf.

[0040] The feather stem 6 is made of unidirectional fiber reinforced plastic, for example, one or more high-strength and high-modulus special continuous fibers are directly compounded or modified compounded with resin material to form the unidirectional fiber reinforced plastic, the tensile and bending strength of the feather stem 6 is higher than 0.8Gpa, the tensile and bending modulus is higher than 15Gpa, the cross-sectional thickness of the feather root 6c and the feather stem 6b is greater than 0.65mm, and the cross-sectional bending resistance coefficient is greater than 0.09mm³. The cross-sectional bending resistance coefficient of the feather stem refers to the cross-sectional bending resistance coefficient of the feather stem when it is stressed in the thickness direction.

[0041] In some specific embodiments, the inner side of the feather stem 6, i.e. the side facing the axis, is a high-strength and high-modulus continuous carbon fiber, and the outer side is a high-strength and high-modulus continuous glass fiber, or a high-strength and high-modulus continuous aramid fiber, or a high-strength and high-modulus continuous ultrahigh molecular weight polyethylene fiber, which is compounded with resin material to form unidirectional fiber reinforced plastic.

[0042] In some specific embodiments, the feather stem is a unidirectional fiber reinforced composite profile with equal cross-section made by impregnating continuous fibers with resin and then by pultrusion process, and then cut and ground. The unidirectional fiber reinforced plastic is directly compounded or modified compounded with one or more high-strength and high-modulus special continuous fibers and resin materials, the special continuous fibers including carbon fibers, glass fibers, aramid fibers and / or ultra-high-density polyethylene fibers. The modified compounding refers to adding materials that can reduce density or increase toughness to the resin matrix before or during compounding, including hollow glass microbeads, foamed plastic microspheres, and / or physical or chemical foaming agents, toughening agents.

[0043] In other specific embodiments, the feather stem is made by impregnating unidirectional tape-shaped fiber prepreg with resin, stacking, heating, pressing and curing, and then cutting and grinding.

[0044] The artificial shuttlecock of the embodiments of the present application has substantially the same quality and quality distribution, stiffness and elasticity as natural high-quality goose and duck feathers, and the same flight performance, and has higher bending strength and impact resistance, shear resistance, tear resistance and fatigue resistance, has excellent resistance to playing, and can also be manufactured in large quantities at low cost.

[0045] As an optional embodiment of the present disclosure, in the above embodiments, the adhesive layer bonds the inner layer of feather leaves and the outer layer of feather leaves together, and covers the stem part 6b and the branch part 6a. Specifically, the adhesive layer 7c can be an elastic hot melt adhesive film or a hot melt adhesive non-woven fabric adhesive film with a thickness of 5-25um bonded with the inner layer and the outer layer respectively; or the adhesive layer can be composed of two parts, one part is a hot melt adhesive layer coated on the stem part and the branch part, and the other part is a film, and the shape is adapted to the shape of the feather leaves. In this way, the weight of the artificial feather head can be reduced to meet the strict requirements of the weight distribution of the artificial shuttlecock.

[0046] The inner feather leaves 7b and the outer feather leaves 7a can be selected from one of the foamed or microcellular foamed polyethylene EPE, foamed polypropylene EPP, foamed polystyrene EPS bubble film, or two different types; EPP or microcellular foamed MPP or EPS film with a more natural appearance can be used as the outer feather leaves. The feather leaves can be made by autoclave pressure slicing process, or extrusion process, or extrusion blow molding process.

[0047] As an optional embodiment of the present application, in the above embodiments, the thickness T of the branch part 6a decreases in the direction towards the top of the feather leaves, which is to reduce the weight of the feather head and maintain the strength and stiffness of the feather stem, so that it better meets the deformation and air resistance characteristics of natural feathers during the playing and flying of the shuttlecock.

[0048] In order to make the artificial shuttlecock of the embodiment of the application consistent with the flight trajectory and flight attitude of the natural feather shuttlecock, the sum of the weight of the head of the feather leaf and the feather branch part is between 40-75 mg; the center of gravity G of the artificial shuttlecock is at a position 3-7 mm from the ball head on the ball skirt axis.

[0049] In order to increase the strength of the stem, the cross section of the stem is square or rectangular, and the bending resistance coefficient of the cross section at the middle position of the feather branch part is 0.5-0.7 times the bending resistance coefficient of the cross section at the bottom of the feather branch part.

[0050] In order to better fix the artificial feather, a plurality of inclined holes 4c are formed on the back of the ball head 4, and the number of the inclined holes 4c is equal to the number of the artificial feathers on the ball skirt 3. The inclined holes 4c are uniformly distributed in the circumferential direction. The inclined holes 4c are filled with glue, or the artificial feathers are inserted into the inclined holes 4c after being glued at the feather part, then the intersection between the feather part and the back of the ball head is glued to reinforce it. The inclined holes 4c are distributed in the longitudinal depth of the tail part 4b of the ball head, and the bottom of the inclined hole 4c is located at the bottom of the head of the ball head.

[0051] In order to better improve the flight performance of the artificial shuttlecock, the feather leaves of adjacent artificial feathers on the ball skirt have overlapping parts. The present application provides a continuous or intermittent cutting line 7d with a total length of 5-20 mm arranged near the stem and along the direction of the stem at the middle position of the feather leaf part inside the overlap, to break the "reverse hair" phenomenon that easily occurs after the feather leaf of the artificial shuttlecock is hit.

[0052] The fiber characteristics of the stem are introduced as follows.

[0053] Glass fiber GF: It is an inorganic fiber made of glass as raw material, which is relatively cheap and has good impregnation in resin. The filament diameter is several microns to twenty microns, and there are many types. The preferred E glass fiber or S glass fiber has high strength and high modulus. Due to the relatively large density and low elastic modulus, it is used as the main material or auxiliary material of the stem of the low-end artificial shuttlecock in the present application.

[0054] Carbon fiber CF: It is a special fiber with a carbon content of more than 90%. The filament diameter is 5-7 microns. According to its mechanical properties, it is divided into two categories: high-strength and high-modulus. The commonly used high-strength carbon fiber T300 or T700 has good rigidity, but the toughness and impact resistance are slightly insufficient. The newly listed T1000 / T1100 has a strength of more than 6Gpa, a modulus of more than 300Gpa, and an elongation at break of 2.2%. It is used as the main material of the stem of the medium-high-end artificial shuttlecock in the present application.

[0055] Aramid fiber AF, full name aramid fiber, commonly used para-aramid fiber density in the middle, good toughness, impact resistance, good comprehensive performance, commonly used as a bulletproof material, used as a high-end and high-end artificial badminton shuttlecock auxiliary material in this application.

[0056] High-strength high-modulus polyethylene fiber UHMWPEF, that is, ultra-high molecular weight polyethylene fiber, has the lowest density, good toughness, impact resistance, but poor impregnation, adhesion, compression resistance and heat resistance with resin materials, and is used as a high-end artificial badminton shuttlecock auxiliary material in this application.

[0057] In addition to these several common high-strength high-modulus fiber materials, with the progress of science and technology, newer and stronger fiber materials have also appeared, such as a PBO Zylon HM fiber material, which is very suitable for making shuttlecock if price is not considered.

[0058] Comparison table of mechanical properties of various high-strength high-modulus special fibers:

[0059]

[0060] The mechanical parameters of the above special fibers will have certain differences due to different manufacturers, different materials and processes.

[0061] The continuous fiber described in this application refers to the fiber in the shuttlecock from head to tail, which is continuous and uninterrupted. The material for making the shuttlecock described in this application is a unidirectional fiber reinforced composite plastic formed by the combination of continuous fiber and resin material. The tensile and bending strength, tensile and bending modulus, and impact and fatigue resistance in the fiber direction are much better than those of composite plastics reinforced by chopped fiber and long fiber.

[0062] The resin material for making the shuttlecock described in this application includes thermosetting resin and thermoplastic resin. Thermosetting resin needs to be modified according to the characteristics of different fiber materials, including but not limited to epoxy resin, unsaturated polyester resin, vinyl resin, etc., with a wide variety. Among them, epoxy resin has strong adhesion and stable performance, but is hard and brittle, and has relatively poor impact strength, which needs to be toughened and modified. Thermoplastic resin includes but is not limited to polypropylene, nylon, polyurethane, etc., which has good toughness, impact resistance, and can be reused, is more environmentally friendly, but has relatively complex process and high production cost.

[0063] The resin modification composite proposed in the application is for the case of using low-cost, small modulus and large density glass fiber or brittle carbon fiber with large density as the reinforcing fiber. In order to improve the stiffness and toughness of the feather stem under the condition of a given weight, the density reduction and toughness modification is adopted, that is, the volume percentage of the hollow glass microbeads, foamed plastic microspheres, physical or chemical foaming agent, toughening agent and the like is not more than 30% in the resin, which can greatly reduce the density of the composite material, and also increase the cross-sectional area and the bending section coefficient under the condition of unchanged weight, so that the bending strength, stiffness and toughness of the feather stem are all increased.

[0064] The continuous fiber and resin material composite process method described in the application has multiple methods, including but not limited to injection molding, molding, resin transfer molding (RTM), heating lamination, pultrusion and the like, and the pultrusion and lamination composite production processes are selected from the above.

[0065] The preferred feather stem profile produced by the pultrusion process in the application has a rectangular cross section, preferably a square cross section. The reason is that in the pultrusion process of small size profiles of about 1mm, the circular and square cross sections are easy to manufacture and produce, and the bending section coefficient of the square cross section is 16% higher than that of the circular cross section under the same cross-sectional area. The thickness of the feather stem profile is required to be not less than 0.65mm, and the bending section coefficient is not less than 0.09mm³, so as to ensure that the ball skirt has high strength and stiffness. The structure of the feather branch part is designed to be variable thickness, which is considered according to the stress characteristics of the feather branch part similar to a cantilever beam, and the approximate equal strength design idea is adopted to minimize the mass and maximize the contact area with the feather leaves under the premise of ensuring the strength and stiffness of the feather branch part. It is noted that when the fiber reinforced resin material made of the feather stem is subjected to bending moment, the outside fiber will be broken and the structure will be delaminated, which is the main reason for the failure of the composite material feather stem. Therefore, the single-sided thickness decreases, and the thickness reduction surface is arranged on the inside of the feather branch, so as to avoid the aggravation of the filament breakage and delamination caused by the thickness reduction.

[0066] In addition to the technical solution of single continuous fiber reinforcement, the application also proposes a profile combining several different fibers with resin to make the shaft, such as placing carbon fiber as the main body on the inside of the shaft, and placing glass fiber, aramid fiber or high-strength and high-modulus polyethylene fiber on the outside of the shaft. It is considered that carbon fiber has excessive rigidity and insufficient toughness, and the impact resistance is not strong enough. When it is hit by a racket, especially by the abnormal impact of the racket frame, it is easy to break. Therefore, one of the other three fiber materials with high strength, good flexibility, impact resistance, but lower compressive strength and elastic modulus is arranged on the outside of the shaft to bear tensile stress and buffer impact force, so as to balance the strengths and weaknesses, and make the shaft have better resistance to playing. At the same time, the combination of two different fiber materials is also an effective method to reduce the cost under the premise of ensuring the given flight performance. For example, glass fiber is low in price, but has low elastic modulus and high specific gravity. If all glass fibers are used, the shaft will be insufficient in rigidity, affecting the flight stability. The combination of glass fiber and carbon fiber can better balance the contradiction between performance and cost.

[0067] In order to test the actual effect of the shaft of the application, the inventor refers to the actual stress state of the feather shaft in the badminton game as a cantilever beam, and proposes a simple and easy method for measuring the mechanical properties of the shaft: the length of the feather branch is set to 40 mm, the feather stem part is semi-rigidly fixed, and a vertical force is applied to the top of the feather branch to measure the bending strength and bending stiffness of the feather branch. When the deformation at the top of the feather branch is 20 mm, the applied force (g) is the equivalent value of the bending stiffness, and the force (g) when the feather branch fails or breaks is the equivalent value of the bending strength.

[0068] The applicant produces four different shaft samples by pultrusion process and mechanical processing. The feather stem part, i.e. the bottom section shape of the feather branch, is 0.9x0.9mm, the top section shape of the feather branch is 0.9x0.4mm, and the material density is controlled to be 1.35-1.5g / ml through density reduction modification method.

[0069] Sample 1: Unidirectional continuous glass fiber reinforced epoxy resin composite shaft with density reduction modification;

[0070] Sample 2: Unidirectional continuous T300 carbon fiber reinforced unsaturated polyester resin composite shaft;

[0071] Sample 3: Unidirectional continuous T700 carbon fiber reinforced unsaturated polyester resin composite shaft;

[0072] Sample 4: Unidirectional continuous glass fiber and T700 carbon fiber combined reinforced unsaturated polyester resin composite shaft.

[0073] Mechanical property comparison table:

[0074]

[0075] In the above table, the anti-creep impact resistance and fatigue resistance are ranked as medium, good, good and excellent, and the comprehensive score is the highest score of 10 points.

[0076] Due to the correlation of the mechanical indicators and types of natural feathers, production place, breeding cycle and many other factors, the dispersion is large, and the data in the table is the average value of incomplete statistics.

[0077] The feather stem made by material selection combination, structure design optimization and process innovation in the application has higher feather branch bending strength by 30%-120% compared with natural duck feather, natural goose feather and existing artificial feather, and the anti-creep impact resistance and fatigue resistance are obviously improved, which means that the resistance to beating can be greatly improved. The feather branch bending stiffness is similar, so that the flight characteristics are similar to those of natural feathers.

[0078] The feather leaf blade described in the application is made of low-density foamed film with good rigidity, resilience, impact resistance, tear resistance and bending fatigue resistance. In theory, all plastic varieties can be made into foamed materials, but the process difficulty, manufacturing cost and product characteristics of foamed materials of different materials are very different. Under the existing foaming process level, polyethylene PE, polypropylene PP, polystyrene PS, polyvinyl chloride PVC, polyurethane PU, polyethylene terephthalate PET and the like can realize low-density foaming. Especially, the supercritical foaming technology using CO2 and N2 as physical foaming agents is more environmentally friendly, and the microporous foaming technology with better performance is also maturing, which lays a foundation for the application of various bubble films in artificial badminton.

[0079] The application selects the following three bubble films that can be applied to the feather leaf blade of the badminton from numerous foamed materials through analysis of the characteristics of various bubble films and in-depth research on the performance requirements of the badminton feather blade and cost comparison, and obtains a better solution through material modification and material combination.

[0080] The EPE foamed film has a density as low as 10 mg / ml and low cost. At a density of 20 g / ml, the tensile strength, compressive strength and bending strength are all higher than 0.15 Mpa, the tear strength is greater than 4.0 N / mm, and the impact strength is good, but the stiffness and resilience are insufficient, and the 10% compression deformation pressure is less than 80 Kpa. Even through modification, such as chemical cross-linking modification XPE and radiation cross-linking modification IXPE, it still cannot meet the performance requirements of medium and high-grade badminton feather blades. In the application, it is used as an inner layer feather blade of medium and high-grade badminton feather blades.

[0081] The mechanical indexes such as high rigidity, high elasticity, high strength mentioned in the application are based on the ordinary EPE bubble film. The application particularly proposes to use low-density foaming, especially microcellular foaming polypropylene EPP (MPP) and polypropylene EPS (MPS) bubble film to make the feather blade, both of which have a closer appearance and performance to natural feathers. The mature foaming process can also achieve a foaming ratio of more than 30 times. The application preferably uses EPP (including MPP) or EPS (including MPS) bubble film with a density of 20-60 mg / ml and a thickness of 0.2-1.2 mm to make the feather piece. Among them, the strength, rigidity, resilience, impact resistance, toughness and fatigue resistance of EPP (MPP) are relatively good, but its foaming process is more complex than the former two. The EPS (MPS) bubble film has excellent bending stiffness, resilience and fatigue bending capacity, but its tear strength and toughness are not ideal, and the application gives reinforcement through toughening modification of the EPS material, pairing with the EPE / MPP bubble film as described below, and a specially designed intermediate adhesive film.

[0082] The application also proposes to use two different materials of foaming film combination to make the inner and outer feather blades, which can make the feather piece obtain better comprehensive performance. The combination of any two of the three preferred EPE, EPS and EPP (including microcellular foaming materials corresponding thereto) in the application can constitute six different feather blades: EPE-EPE, EPS-EPE, EPP-EPE, EPS-EPS, EPS-EPP, EPP-EPP, and according to their flight performance, durability and appearance, they are used as low-end, medium-end and high-end badminton respectively to meet different application scenarios and market demand. The following table is the performance comparison of the EPS-EPE, MPP-EPE and EPS-MPP combined films of the application relative to the EPE-EPE feather piece on the market:

[0083] The inner and outer feather pieces adopt equal thickness sandwich film combination, and the area density is controlled at 6-8 mg / cm².

[0084] The mechanical performance indexes such as strength and rigidity of the film material have a strong correlation with its density, so the index values in the table are also not complete statistical value intervals.

[0085]

[0086] As can be seen from the table, through the combination of film pieces with different characteristics adopted by the application, the important performance indexes of the feather piece are greatly improved, and the flight performance and durability of the badminton made of artificial feathers are also greatly improved accordingly.

[0087] The design of the double-piece foamed plastic film wrapping the stem and branch of the fiber-reinforced composite resin feather shaft can better buffer the impact force of the racket on the feather shaft, making up for the defect of insufficient impact resistance of the feather shaft when using carbon fiber and thermosetting epoxy resin material. Meanwhile, the fiber-reinforced feather shaft is relatively thin, and the feather shaft is black when using carbon fiber. The white covering and widening of the feather neck can improve the wind resistance characteristics and appearance of the feather shaft, making it look more like natural feathers. The feather blade of this design includes two parts, the feather head corresponding to the branch position, with a surface area of 4.0-5.5 cm², and the feather neck corresponding to the stem position, with a surface area of 0.6-0.8 cm².

[0088] The preferred scheme of setting a hot melt adhesive film between the double-piece foamed film in the application is also an effective method to improve the tear resistance of the feather blade. If it is simply glued, the thickness and uniformity are difficult to control, not to mention that without the transverse cross-linking effect of the film, the effect on improving the tear resistance of the feather blade is limited. The use of hot melt adhesive film, especially non-woven fabric-based hot melt adhesive film, has the advantages of simple process, good consistency, and can greatly improve the tear resistance of the feather blade, thereby improving the durability of the badminton. In some cases, one of the two feather blades can be cancelled, or combined with the non-woven fabric-based adhesive film.

[0089] As mentioned earlier, the center of gravity of the badminton is crucial to the flight performance of the badminton, and for this purpose, the application designs many technical solutions to reduce the weight of the feather branch to ensure that the center of gravity G of the entire badminton is located on the center line A of the conical skirt, and the distance from the back plane of the ball head is between 3-7 mm, preferably within the range of 4-6 mm.

[0090] There are differences between artificial feathers and natural feathers in structure and aerodynamic performance. The application proposes a method of adjusting the flight performance of the badminton by adjusting the deflection angle C of the feather. The feather deflection setting is to generate a tangential force to drive the badminton to rotate during flight, and the gyro effect is beneficial to the stability of the flight trajectory of the badminton. The rotation speed of the natural badminton under standard wind speed is generally controlled at 300-500 rpm, while the rotation speed of the artificial badminton under standard wind speed will be adjusted according to the blade resistance characteristics. The size of the deflection angle is the main factor determining the rotation speed of the badminton, thereby having a greater impact on the flight performance.

[0091] After the feather deflection arrangement, an orderly stack between adjacent vanes is formed. The deformation of the vane after being hit will destroy the stack order. The vane of the natural feather is composed of countless feather filaments, which can be freely separated and combined, so that the vane can quickly recover to the given stack order. The vane blade of the artificial feather is an integral sheet, which is different from the vane of the natural feather. After the vane is deformed, it is difficult to recover to the original stack order, that is, the “flipping” phenomenon occurs. Even after the rigidity and elasticity of the shank and the vane are improved in the present application, the “flipping” phenomenon still occurs occasionally. Therefore, the present application further provides a continuous or intermittent cutting line in the middle part of the inner vane blade of the stack along the direction of the shank, such as a cutting line of 2x (discontinuous 8 mm + continuous 5 mm) starting from 8 mm from the top end of the blade, to weaken the recovery resistance caused by the bending rigidity of the adjacent inner vane blade, so as to facilitate the rapid resetting of the outer vane.

[0092] The present application will be further described below in conjunction with specific examples.

[0093] Example 1: Badminton with continuous glass fiber GF unidirectional density-reduced modified reinforced composite plastic shank

[0094] In the present application, the shank (6) is made of continuous glass fiber unidirectional reinforced resin composite material. A certain domestic ultra-high modulus glass fiber with a tensile strength of 3.3 Gpa and a modulus of 100 Gpa is selected to be compounded with epoxy resin and density-reduced hollow glass microbeads in a volume percentage of 35:40:25 by pultrusion process. The density is 1.36 g / ml, the tensile strength is higher than 1.0 Gpa, and the tensile modulus is higher than 20 Gpa. The shank (6) designed according to the present application has a length of 75 mm, a square cross section of 0.9x0.9 mm, and a bending section modulus of 0.12 mm³. The thickness of the vane portion (6c) decreases from 0.9 mm at the bottom to 0.4 mm at the top. The weight is 32 mg. The maximum bending moment Mm that the vane portion can withstand is 12 N.cm, which exceeds the bending moment value that the vane of ordinary duck feather can withstand. The toughness is also higher than that of goose and duck feathers.

[0095] The outer layer and the inner layer of the vane can be selected as EPE bubble film, and the middle adhesive film is non-woven fabric based hot melt adhesive film. The surface density of the composite vane is 6.0-6.5 mg / cm². When the area of the vane blade is 4.5-5 cm², the mass of the vane is 30-33 mg. The mass of the vane head and the vane portion is 60-65 mg.

[0096] The badminton produced by the artificial feather has the same flight performance as the duck feather badminton of medium quality. The durability is better than that of high-quality duck feather, which is 5 stars. It is suitable for entry-level amateur badminton enthusiasts and is cost-effective.

[0097] Example 2: Badminton with continuous carbon fiber unidirectional reinforced composite plastic shank

[0098] The application is made of continuous carbon fiber unidirectional reinforced resin composite to make the quill, and the application is made of 40% volume ratio of carbon fiber such as T700 with performance equivalent to or even better than T300-3k and toughened modified vinyl resin VE to be compounded into plastic profile by pultrusion process, the density is about 1.34 g / ml, the tensile strength is >1.4 Gpa, the tensile modulus is >40 Gpa, the quill shape design is the same as that of embodiment 1, the weight of the feather branch part is 31 mg, and the maximum bending moment Mm that can be borne by the bottom of the feather branch part is >16 Ncm, which is higher than the bending moment value that can be borne by high-quality goose and duck feathers, and the stiffness is higher than that of high-quality goose feathers.

[0099] The outer layer of the feather leaf is provided with EPS bubble film, the inner layer is EPE, and the middle adhesive film is non-woven fabric-based hot melt adhesive film, and the mass of the feather leaf and feather branch part is less than 65 mg.

[0100] The shuttlecock produced by the artificial feather has a flight performance equivalent to that of high-quality goose feather shuttlecock, which is 5 stars, the impact resistance of the quill is good, but the quill will still break when subjected to strong impact, the durability is 5 stars, and the shuttlecock is suitable for use by amateur badminton players at a medium-high level.

[0101] Embodiment 3: Badminton with continuous carbon fiber and continuous glass fiber unidirectional reinforced reduced-density modified composite plastic quill

[0102] The application is made of continuous carbon fiber, continuous glass fiber, epoxy resin and hollow glass microspheres with performance equivalent to or higher than T300 in a volume percentage of 27.5:12.5:50:10 to be compounded into unidirectional reinforced plastic profile by pultrusion process, and the glass fiber is mainly distributed on the outside of the quill, and the carbon fiber is distributed on the inside of the quill. The density of the composite profile is 1.34 g / ml, and the other designs of the feather leaf are the same as those of embodiment 2. The mass of the feather leaf and feather branch part is 63 mg.

[0103] The performance index is close to that of embodiment 2, and the flight performance is 5 stars. The impact resistance of the quill is good, but the glass fiber and the carbon fiber are still brittle materials, and the quill will still break when subjected to strong or abnormal impact. The durability of the shuttlecock is 6 stars, and the shuttlecock is suitable for use by amateur badminton players at a medium-high level when practicing or playing.

[0104] Embodiment 4: Badminton with continuous carbon fiber and continuous aramid fiber unidirectional reinforced composite plastic quill

[0105] The application is made of continuous carbon fiber, continuous aramid fiber and PP resin with a volume ratio of 30:20:50, which is compounded into a unidirectional reinforced plastic profile by extrusion impregnation + pultrusion process. The aramid fiber is mainly distributed on the outside of the shaft, and the carbon fiber is distributed on the inside. The composite profile density is 1.30g / ml, and the tensile strength is >1.4Gpa. The shaft cross section is set to a square of 0.94x0.94mm, and the bending section coefficient is 0.138. The maximum bending moment Mm that the bottom of the feather branch can withstand is >20Ncm, which is twice the bending moment that the general natural feather can withstand. The top section thickness of the feather branch is 0.40mm, and the weight of the feather branch is 31mg.

[0106] The outer and inner layers of the pinnate leaf are made of MPP film, and the comprehensive performance is excellent. The composite pinnate leaf surface density is 5.4mg / cm², and the mass of the pinnate leaf and feather branch is 60-65mg.

[0107] The flight performance of the artificial shuttlecock of this example is better than that of example 3, which is 6 stars; the impact resistance of the feather shaft is good, and the resistance of the shuttlecock to playing is improved to 7 stars, and it will not easily break when subjected to strong abnormal hitting. It is suitable for high-level badminton enthusiasts or even professional athletes to practice or play.

[0108] Example 5: Artificial shuttlecock of continuous carbon fiber and continuous high-strength high-modulus polyethylene fiber unidirectional reinforced composite plastic shaft

[0109] The application is made of 25% volume ratio of continuous unidirectional carbon fiber prepreg with T800 performance or higher (such as T1000 / T1100, etc.) and 20% volume ratio of continuous high-strength high-modulus polyethylene fiber unidirectional prepreg and resin, which is compounded by laminated molding or special designed pultrusion process. Since the polyethylene fiber is not resistant to high temperature, and the adhesion with other resins is not good, surface modification treatment and reasonable selection of resin curing temperature must be carried out and strictly controlled, so that the high-strength high-modulus polyethylene fiber is mainly distributed on the outside of the shaft. The composite rod density is 1.25g / ml, the cross section is set to a square of 0.96x0.96mm, the bending section coefficient is 0.16, and it has excellent bending strength, rigidity, elasticity, toughness, impact resistance and fatigue resistance, which is a shuttlecock that cannot be broken. The pinnate leaf is made of MPS + MPP + non-woven fabric based hot melt adhesive composite.

[0110] The flight performance of the artificial shuttlecock of this example is 7 stars, and the resistance of the shuttlecock to playing can also reach 7 stars. It is suitable for high-level badminton enthusiasts or professional athletes to practice or play.

[0111] The above detailed description does not limit the scope of the application. Various modifications, combinations, sub-combinations and alternatives can be made to the detailed embodiment disclosed herein without departing from the spirit and the principles of the application. Any modification, equivalent replacement or improvement made within the spirit and principles of the application shall fall within the scope of the application.

Claims

1. An artificial shuttlecock, characterized in that, Comprise: a ball skirt and a ball head, wherein the ball skirt comprises a plurality of artificial feathers and at least two supporting coils, the artificial feather comprises a feather stem and a feather leaf, the feather stem comprises a feather root, a feather stem and a feather branch, the feather leaf comprises an inner feather leaf, an outer feather leaf and an intermediate adhesive layer; the inner feather leaf and the outer feather leaf are bonded together by the intermediate adhesive layer and cover the feather stem and the feather branch; the feather root is arranged in the ball head, and the supporting coil fixes the feather stem; the feather stem is made of unidirectional continuous fiber reinforced composite plastic, the longitudinal tensile and bending strength of the feather stem is higher than 0.8Gpa, and the longitudinal tensile and bending modulus is higher than 15Gpa, the cross-sectional thickness of the feather root and the feather stem is greater than 0.65mm, and the cross-sectional bending coefficient is greater than 0.09mm³; the feather leaf is made of low-density high-strength high-rigidity foamed plastic sheet.

2. The artificial feather ball according to claim 1, wherein the thickness of the feather branch decreases in the direction towards the top of the feather leaf.

3. The artificial feather ball according to claim 2, wherein the cross section of the feather stem is square or rectangular, and the cross-sectional bending coefficient of the feather branch at the longitudinal middle position is 0.5-0.7 times that of the bottom of the feather branch.

4. The artificial feather ball according to claim 3, wherein the sum of the weight of the head of the feather leaf and the feather branch is between 40-75mg; and the center of gravity of the artificial feather ball is located at a position 3-7mm away from the ball head on the axis of the ball skirt.

5. The artificial feather ball according to claim 1, wherein the unidirectional continuous fiber reinforced composite plastic is directly compounded or modified compounded by one or more high-strength and high-modulus special continuous fibers and resin materials, and the special continuous fibers include carbon fiber, glass fiber, aramid fiber and ultra-high molecular weight polyethylene fiber.

6. The artificial feather ball according to claim 5, wherein the modified compounding refers to adding materials that can reduce density or increase toughness to the resin matrix before or during compounding, including hollow glass microbeads, foamed plastic microspheres, and / or physical or chemical foaming agents and toughening agents.

7. The artificial feather ball according to claim 5, wherein the feather stem is made of unidirectional continuous fiber reinforced plastic by pultrusion or laminated compounding of one or more high-strength and high-modulus special fibers and resin.

8. The artificial feather ball according to claim 1, wherein the outer feather leaf and the inner feather leaf are made of the same kind or different kinds of foamed or microcellular foamed polyethylene EPE, polypropylene EPP and polystyrene EPS bubble film.

9. The artificial feather ball according to claim 1, wherein the intermediate adhesive layer is a single-layer or double-layer elastic hot melt adhesive film or hot melt adhesive non-woven fabric adhesive film with a thickness of 5-25um.

10. The artificial feather ball according to claim 1, wherein The back of the ball head is provided with a number of circumferentially distributed inclined holes equal to the number of artificial feathers on the ball skirt. The inclined holes are filled with glue, or the artificial feathers are inserted into the inclined holes after being glued at the feather portion, and then the joint between the feather portion and the back of the ball head is glued to reinforce.

11. The artificial feather ball according to claim 1, wherein The feather blade portions of adjacent artificial feathers on the ball skirt overlap each other, and the middle portion of the feather blade portion on the inner side is provided with a continuous or intermittent cutting line with a total length of 5-20 mm close to and along the feather stem.

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