JP2015167718A - shuttlecock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shuttlecock that has a flight characteristic close to a natural shuttlecock in spite of having artificial feathers compared to a conventional artificial one and that also has high durability.SOLUTION: The shuttlecock has a hemisphere base body 2 and a plurality of artificial feathers 3 connected to the base body 2. The artificial feather 3 includes a wing part 5 and a shaft 7 connected thereto. In the wing part 5 and the shaft 7, the main surface, a surface having a relatively large area in the wing part 5 is fixed in the manner inclined to the neutral axis in which cross sectional secondary moment is maximized in the cross section of the shaft 7 that is vertical in the extended direction of the shaft 7. Each shaft 7 of the plurality of artificial feathers 3 is arranged annularly on the surface of the base body 2 and, an angle formed by the neutral axis of the shaft 7 and by the radial direction extending toward the shaft 7 from the center of the region where the shafts 7 are annularly arranged is not less than 85 degrees and not more than 95 degrees.

Description

  The present invention relates to a shuttlecock, and more particularly to a shuttlecock provided with artificial feathers.

  Conventionally, as shuttlecocks for badminton, those using waterfowl feathers (natural shuttlecocks) for the feathers, and feathers (artificial feathers) consisting of wings and shafts artificially manufactured with nylon resin or the like were used. Things (artificial shuttlecocks) are known. A natural shuttlecock is more expensive than a shuttlecock using artificial feathers because it takes time to obtain a certain quality of such natural feathers. In addition, the supply of waterfowl feathers has been drastically reduced in recent years due to changes in the food situation of waterfowl feather supply countries and the large-scale disposal of waterfowl caused by the bird flu epidemic. It has become a thing. For this reason, a shuttlecock using artificial feathers of inexpensive and stable quality has been proposed.

  Artificial shuttlecocks with artificial feathers have the same flight performance as natural shuttlecocks, high durability that can suppress the drop in flight performance against repeated hits, and the same feel as natural shuttlecocks. Is required.

  In general, in an artificial shuttlecock, a plurality of artificial feathers are annularly arranged on a hemispherical base body, and adjacent artificial feathers are partially overlapped. In other words, a predetermined angle at which the main surface (hereinafter simply referred to as main surface), which is a surface having a relatively large area in the wing, is not perpendicular to the radial direction extending from the center of the surface of the base body on which the artificial feather is disposed. The artificial feather is connected to the base body so as to be inclined only. Such a structure mimics a natural shuttle, but is intended to give a rotational force to the shuttlecock.

  For example, a shuttlecock described in JP 2012-24157 A (Patent Document 1) has the above-described structure.

JP 2012-24157 A

  However, in the shuttlecock artificial feather described in Patent Document 1, the cross section of the wing shaft part is trapezoidal. In such an artificial feather, as compared with the case where the cross section of the wing shaft portion is rectangular, the second moment of section of the cross section perpendicular to the direction in which the wing shaft portion extends is small, and the bending rigidity of the wing shaft portion is lowered. When the bending rigidity of the wing shaft portion is low, deformation of the artificial shuttlecock becomes large when a hit is applied to the artificial shuttlecock.

  Moreover, since the shaft of the artificial feather is connected to the base body so that the main surface of the wing portion is inclined with respect to the radial direction extending from the center of the surface of the base body, there is a possibility that the deformation due to impact becomes larger. As a result, the flight characteristics of such an artificial shuttlecock are greatly different from the flight characteristics of the natural shuttlecock. Further, the durability of such an artificial shuttlecock is insufficient as a shuttlecock.

  The present invention has been made to solve the above-described problems. A main object of the present invention is to provide a shuttlecock that has artificial feathers but has a flight characteristic close to that of a natural shuttlecock compared to a conventional artificial shuttlecock and high durability.

  A shuttlecock according to the present invention includes a hemispherical base body and a plurality of artificial feathers connected to the base body, and the artificial feather includes a wing part and a shaft connected to the wing part, The main surface, which is a surface having a relatively large area in the wing portion, is inclined with respect to the neutral axis where the secondary moment in the cross section of the axis perpendicular to the extending direction of the shaft is maximum. The shafts of the plurality of artificial feathers are annularly arranged on the surface of the base body, and the neutral shaft of the shaft and the center of the region where the shaft is annularly arranged are directed from the center to the axis. The angle formed by the extending radial direction is not less than 85 degrees and not more than 95 degrees.

  ADVANTAGE OF THE INVENTION According to this invention, although it has an artificial feather | wing, compared with the conventional artificial shuttlecock, a flight characteristic is close to a natural shuttlecock, and a shuttlecock with high durability can be provided.

It is a side view for demonstrating the shuttlecock which concerns on this Embodiment. It is sectional drawing seen from the line segment II-II in FIG. It is a top view for demonstrating the shuttlecock which concerns on this Embodiment. It is a figure for demonstrating the artificial feather | wing of the shuttlecock which concerns on this Embodiment. It is sectional drawing seen from the line segment VV in FIG. It is sectional drawing seen from the line segment VI-VI in FIG. It is a figure for demonstrating the axis | shaft of the artificial feather | wing of the shuttlecock which concerns on this Embodiment. It is a figure for demonstrating rotation when the shuttlecock which concerns on this Embodiment is flying. It is a figure for demonstrating the modification of the axis | shaft of the artificial feather | wing of the shuttlecock which concerns on this Embodiment. It is sectional drawing for demonstrating the modification of the axis | shaft of the artificial feather shown in FIG. It is sectional drawing for demonstrating the other modification of the axis | shaft of the artificial feather shown in FIG. It is sectional drawing for demonstrating the further another modification of the axis | shaft of the artificial feather shown in FIG. It is a figure for demonstrating the modification of the artificial feather | wing shown in FIG. In an Example, it is sectional drawing for demonstrating the method to measure the angle of the main surface of the wing | blade part of an artificial feather, and the neutral axis of an axis | shaft.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

An embodiment of a shuttlecock according to the present invention will be described with reference to FIGS.
1 to 3, shuttlecock 1 according to the present embodiment includes hemispherical base body 2, a plurality of artificial feathers 3 connected to base body 2, and a plurality of artificial feathers 3. It consists of a fixing string-like member (warp thread) 14 for fixing each other and a middle thread 15 for maintaining the laminated state of the plurality of artificial feathers 3.

  Referring to FIG. 2, the planar shape of the fixing surface portion of base body 2 is circular. A plurality of insertion holes are formed in a ring shape along the outer periphery of the fixing surface portion of the base body 2. The planar shape of each insertion hole in the fixing surface portion of the base body 2 is provided as an arbitrary shape that can fit the shaft 7 of the artificial feather 3 described later, and is, for example, a rectangular shape. A major axis direction of each insertion hole of the base body 2 and a radial direction D extending on the fixing surface portion of the base body 2 so as to pass through the center of the insertion hole from the center 12 of the ring formed by each insertion hole. The formed angle θ1 is ± 5 degrees or less, preferably 0 degrees (the radial direction D of the base body and the long axis direction of the insertion hole are parallel).

  The artificial feather 3 has a wing part 5 and a shaft 7 connected to the wing part 5. The base part of the shaft 7 of the artificial feather 3 is inserted into each insertion hole of the base body 2, so that a plurality of (for example, 15) artificial feathers 3 are attached to the fixing surface portion of the base body 2. It arrange | positions at the annular | circular shape so that the center 12 may be enclosed along the outer peripheral part of the surface part for fixation. In this way, the shuttlecock 1 is configured by connecting the base body 2 and the artificial feather 3. Referring to FIG. 2, the shape of the cross section perpendicular to the extending direction of shaft 7 (details will be described later) has a rectangular shape. The major axis L of the cross section of the shaft 7 is provided along the radial direction D extending from the center 12 of the base body 2.

  At this time, the adjacent artificial feathers 3 are arranged so that the wing parts 5 partially overlap each other. The plurality of artificial feathers 3 are arranged such that the distance between them increases as the distance from the base body 2 increases (the inner diameter of the cylindrical body formed by the plurality of artificial feathers 3 increases as the distance from the base body 2 increases). Has been. For example, when the artificial feather 3 is viewed from the center 12 side of the base body 2, the region 5 </ b> L located on the left side with respect to the shaft 7 (fixed shaft portion 10 shown in FIG. 4) of one wing portion 5 The region 5L of one wing portion 5 of the adjacent artificial feather 3 is located on the outer periphery side of the region 5R of the other wing portion 5 and is partly located. May be arranged so as to overlap each other.

  The string-like member 14 fixes the shafts 7 of the plurality of artificial feathers 3 to each other. The string-like member 14 may be provided at a plurality of locations in the extending direction of the shaft 7 of the artificial feather 3. The middle thread 15 fixes the wings 5 of the plurality of artificial feathers 3 to each other. The relative positional relationship between the plurality of artificial feathers 3 is maintained by the base body 2, the string-like member 14, and the middle thread 15.

  Next, the artificial feather 3 will be described with reference to FIGS. Referring to FIG. 4, the artificial feather 3 constituting the shuttlecock 1 has a wing part 5 and a shaft 7 connected to the wing part 5. The shaft 7 includes a wing shaft portion 8 disposed so as to protrude from the wing portion 5 and a fixed shaft portion 10 connected to the wing portion 5. The wing shaft portion 8 and the fixed shaft portion 10 are arranged so as to extend in the same line, and constitute one continuous shaft 7.

  Referring to FIGS. 2 and 5, the shape of the cross section perpendicular to the extending direction of shaft 7 is, for example, a rectangular shape, and can be fitted to the rectangular through-hole provided in base body 2 as described above. it can. The cross section of the shaft 7 has a long side having a length W1 and a short side having a length W2 shorter than the length W1, and the maximum value of the cross-section secondary moment in the cross section of the shaft 7 is determined. It has a symmetry axis (neutral axis N) to be applied and a symmetry axis (long axis L) that is orthogonal to the neutral axis N and that gives the minimum value of the secondary moment of section. In the shaft 7 shown in FIG. 5, the neutral axis N extends on the vertical bisector of the long side, and the long axis L extends on the vertical bisector of the short side.

  The artificial feather 3 is connected and fixed to the base body 2 by inserting the shaft 7 into the insertion hole of the base body 2 as described above. That is, referring to FIG. 2B, in the state where artificial feather 3 is connected and fixed to base body 2, angle θ1 formed by long axis L of shaft 7 and radial direction D of base body 2 is, for example, ± It is 5 degrees or less, and preferably 0 degrees (the major axis L and the radial direction D are parallel). That is, the angle θ1 formed by the neutral axis N of the shaft 7 and the tangential direction T perpendicular to the radial direction D of the base body 2 is, for example, ± 5 degrees or less, and preferably 0 degrees. From a different point of view, the angle θ2 formed by the neutral axis N and the radial direction D of the base body 2 is not less than 85 degrees and not more than 95 degrees, preferably 90 degrees (the neutral axis N and the radial direction D are orthogonal). is there.

  Referring to FIG. 5, main surfaces 5 </ b> A and 5 </ b> B, which are surfaces having a relatively large area in wing portion 5, are inclined by angle θ <b> 3 with respect to neutral axis N of shaft 7. And the connection is fixed. The angle θ3 is, for example, not less than 15 degrees and not more than 45 degrees, preferably not less than 20 degrees and not more than 40 degrees, and more preferably not less than 25 degrees and not more than 35 degrees. From a different point of view, as described above, when the wing shaft portion 8 is lowered, the region 5R located on the right side of the fixed shaft portion 10 in the wing portion 5 projects forward from the shaft 7. The region 5 </ b> L located on the left side of the fixed shaft portion 10 in the wing portion 5 is provided so as to protrude rearward from the shaft 7. In this case, referring to FIG. 4A, when the side surface 8b including the short side in the cross section perpendicular to the extending direction of the shaft 7 is viewed in plan, the wing portion 5 intersects with the main surfaces 5A and 5B relatively. A side surface having a small area is confirmed simultaneously with the main surface 5A. On the other hand, referring to FIG. 4B, when the main surface 5A of the wing portion 5 is viewed in plan, the side surface 8a including the long side in the cross section perpendicular to the extending direction of the shaft 7 is confirmed simultaneously with the side surface 8b. .

  On the contrary, when the wing shaft portion 8 is lowered, a region 5L located on the left side of the fixed shaft portion 10 in the wing portion 5 is provided so as to protrude forward from the shaft 7. In addition, a region 5 </ b> R located on the right side of the fixed shaft portion 10 in the wing portion 5 may be provided so as to protrude rearward from the shaft 7. In this case, in the shuttlecock 1 shown in FIG. 3, the region 5L of one wing portion 5 of the adjacent artificial feather 3 is located on the inner peripheral side of the region 5R of the other wing portion 5 and partially overlaps this. May be arranged.

  Referring to FIGS. 5 and 6, the wing part 5 includes a foam layer 92 and a shaft fixing layer 91 arranged so as to sandwich the fixed shaft part 10, and the foam layer 92 and the shaft fixing layer 91 are connected to each other. It has adhesive layers 93 and 94 for fixing. That is, in the wing part 5, the foam layer 92 and the shaft fixing layer 91 are laminated so as to sandwich the fixed shaft part 10. Further, in the wing portion 5, the adhesive layers 93 and 94 are connected to connect the foam layer 92 and the shaft fixing layer 91 to each other and connect and fix the fixed shaft portion 10 to the foam layer 92 and the shaft fixing layer 91. Is arranged. From a different point of view, in the wing portion 5, when the shuttlecock 1 is configured, the adhesive layer 93 is laminated on the foam layer 92 positioned on the outer peripheral side with respect to the shaft fixing layer 91. On the adhesive layer 93, the fixing shaft portion 10 is disposed so as to be positioned at a substantially central portion of the adhesive layer 93 and the foam layer 92. The other adhesive layer 94 is arranged so as to extend from the fixed shaft portion 10 to the adhesive layer 93. A shaft fixing layer 91 is disposed on the adhesive layer 94. In the wing portion 5 shown in FIGS. 5 and 6, when the shuttlecock 1 is configured, the foam layer 92 is positioned on the outer peripheral side with respect to the shaft fixing layer 91, but the foam layer 92 is the shaft fixing layer. 91 may be configured to be located on the inner peripheral side.

  As a material constituting the foam layer 92, for example, a resin foam, more specifically, for example, a polyethylene foam (polyethylene foam) can be used. Similarly, a resin foam can be used for the shaft fixing layer 91. Moreover, as a material which comprises the axis | shaft fixed layer 91, arbitrary materials, such as a film consisting of resin etc., or a nonwoven fabric other than a polyethylene foam, can be used, for example.

  As a material constituting the adhesive layers 93 and 94, for example, a double-sided tape can be used. In the artificial feather 3, polyethylene foam can be used as the foam layer 92 and the shaft fixing layer. The extrusion direction of the polyethylene foam is a direction perpendicular to the extending direction of the shaft 7 in FIG. 4 (the horizontal direction in FIG. 4). It is preferable that In this case, since the shaft 7 is connected and fixed to the wing portion 5 so as to intersect the extrusion direction of the polyethylene foam constituting the wing portion 5, the wing portion 5 extends in a direction along the extending direction of the shaft 7. The probability of occurrence of defects such as tearing can be reduced.

  The material constituting the shaft 7 is, for example, uniaxially stretched polyethylene terephthalate (super stretched material). In addition, nylon can be used as a material constituting the shaft 7, and nylon 12, nylon 11, nylon 10, nylon 610, nylon 612, nylon 1010, and the like can be preferably used. In order to reinforce the fiber, nylon added with potassium titanate whisker, glass or the like can also be used. Further, polycarbonate, polypropylene, polyethylene or the like can be used as a material constituting the shaft 7.

  The specific gravity of the material constituting the shaft 7 is preferably 1.5 or less, and more preferably 1.4 or less. Further, the bending elastic modulus of the material of the shaft 7 is preferably 2000 MPa or more and 10,000 MPa or less. Note that the numerical value range is not limited as long as the specific gravity (mass) and the bending elasticity (axial deformation) do not affect the flight characteristics of the shuttlecock 1.

  The shaft 7 has a width W1 (see FIG. 2B) of the outer circumferential surface in the cross-sectional shape gradually from the root portion (the end portion on the side connected to the base body 2) toward the tip side. It is getting smaller. The length W2 (see FIG. 2B) of the surface in the thickness direction of the outer periphery in the cross-sectional shape of the shaft 7 is constant over the entire length of the shaft 7. 6 and 7, the shaft 7 is shaped to warp one side when viewed from the side surface (the side surface 8a in FIG. 4A). In the shuttlecock 1, as the distance from the base body 2 increases, the distance between the artificial feathers 3 arranged in an annular shape gradually increases (so that the shaft 7 spreads outside the shuttlecock 1). The artificial feather 3 is connected to the base body 2 so that the warping direction (the protruding direction of the convex shape formed by the warping of the shaft 7) is directed to the inner peripheral side of the shuttlecock 1.

  The design length of the shaft 7 (the length of the line segment ef in FIG. 7 or FIG. 9) can be 76 mm or more and 79 mm or less. According to the competition rules of the Japan Badminton Association, the length of the wings must be the same length in the range of 62mm to 70mm, from the tip to the top (to the fixing surface of the base body). This is because it is specified. For example, when the length of the portion (buried portion) inserted into the insertion hole of the base body 2 at the base portion of the shaft 7 is 63 mm or more and 65 mm from the tip of the blade to the top of the base, Thus, the design length of the shaft 7 is not less than 76 mm and not more than 79 mm.

  4B, 6 and 7, in the artificial feather 3, the shaft 7 is warped toward the foam layer 92 side (that is, the outer peripheral side of the shuttlecock 1). Also good. From a different point of view, the shaft 7 may be warped so as to protrude toward the shaft fixing layer 91. Further, the wing portion 5 is foamed in a direction intersecting with the extending direction of the shaft 7 (for example, a width direction perpendicular to the extending direction of the shaft 7 and along the surface of the wing portion 5). It may be in a state of warping to the body layer 92 side (the outer peripheral side of the shuttlecock 1) (that is, a state in which the wing portion 5 is warped so as to protrude toward the shaft fixing layer 91). In this case, the state in which the artificial feather 3 is warped in the extending direction of the shaft 7 and the state in which the wing portion 5 is warped in the direction intersecting with the extending direction of the shaft 7 are simultaneously generated. Alternatively, only one of the warpages may occur. Such warping is realized by a conventionally well-known method such as applying heat treatment to the constituent material of the shaft 7 and the wing portion 5 or forming the constituent material of the shaft 7 and the wing portion 5 in a warped state from the beginning. be able to.

  Here, the extending direction of the shaft 7 is defined as follows. That is, referring to FIG. 7, on the side surface of the cross-sectional shape of the shaft 7 viewed from the surface side in the width direction, the middle point of the line segment ab connecting the upper end corner portion a and the lower end corner portion b on the front end side is point e. And In addition, a curved surface (upper curve) obtained by extending the curved surface of the upper surface of the shaft 7 in FIG. 7 to the root side of the shaft 7 and a curved surface (lower curve) obtained by extending the curved surface of the lower surface of the shaft 7 to the root side of the shaft 7. ) A line segment (base line segment) parallel to the line segment ab is considered on the root side of the shaft 7. Then, an intersection of the root side line segment and the upper curve is a point c, and an intersection of the lower curve is a point d. Furthermore, let the center (middle point) of the line segment cd be a point f. The position of the root side line segment is determined so that the distance between the point e and the point f becomes the design length of the shaft 7. In FIG. 7, the base side of the shaft 7 has a wedge shape in which the height of the side surface decreases toward the end portion, and the tip end corner portion of the wedge shape coincides with the point f. A straight line connecting the points e and f is defined as the extending direction of the shaft 7.

  The curvature radius of the curved surface (side surface 8b of the wing shaft portion 8) in the shaft 7 shown in FIG. 7 is designed in consideration of the angle θ1 (see FIG. 2) formed by the long axis L and the radial direction D of the base body 2. However, it can be 600 mm or less, preferably 450 mm or less. With such a design, it is possible to prevent the shuttlecock 1 from flying too much, and it is possible to prevent deviation from the flight characteristics of the natural shuttlecock. The curved surface of the shaft 7 includes a curved surface facing the inner peripheral side of the shuttlecock 1 and a curved surface facing the outer peripheral side, but these radii of curvature may be different from each other or the same value.

  Next, the effect of the shuttlecock 1 which concerns on this Embodiment is demonstrated. According to the shuttlecock 1 according to the present embodiment, the cross section perpendicular to the extending direction of the shaft 7 of the artificial feather 3 is rectangular, and an angle θ1 formed by the long axis L with the radial direction D of the base body 2. Since the base body 2 and the shaft 7 are connected and fixed so that the angle becomes ± 5 degrees or less, the rigidity of the shaft 7 in the radial direction D can be increased. As a result, the shuttlecock 1 receives the greatest force in the radial direction D of the base body 2 when hit with a racket, but the rigidity of the shaft 7 in the radial direction D is high, so the deformation of the shaft 7 is kept small. be able to. As a result, the load applied to the wing part 5 and the string-like member 14 with the deformation of the shaft 7 can be reduced, and the durability of the shuttlecock 1 can be enhanced. Further, since the durability of the shaft 7 can be increased without increasing the thickness of the shaft 7 of the artificial feather 3, the overall weight of the shuttlecock 1 is not increased, and the weight and durability of the shuttlecock 1 are reduced. It is possible to achieve both improvement.

  Further, since the angle θ3 formed by the main surface 5A of the wing part 5 and the neutral axis N of the shaft 7 is set to 15 degrees or more and 45 degrees or less, the adjacent wing parts 5 in the plurality of artificial feathers 3 are fixed to each other. A partially laminated state is formed in relation. At this time, since the angle θ1 formed by the major axis L of the shaft 7 and the radial direction D is set to be ± 5 degrees or less, the angle θ1 is out of the numerical range and the angle θ3 is 0 degrees (ie, Compared to the conventional shuttlecock provided on the main surface 5A of the wing 5 and the neutral axis N of the shaft 7), a larger air flow can be formed in a certain direction around the shuttlecock 1. .

  Specifically, referring to FIG. 8, the air hitting wing part 5 flows in the A1 direction, and thereby generates a force in the A2 direction due to its reaction. Thereby, the shuttlecock 1 can rotate by receiving the rotational force in the R direction during flight. As a result, when the shuttlecock 1 is caused to fly, a large rotational force can be applied to the shuttlecock 1 to increase the number of revolutions of the shuttlecock 1, and thus the flight characteristics equivalent to those of the natural shuttlecock can be realized. .

  On the other hand, the conventional shuttlecock has an angle formed by the main surface of the wing and the neutral axis (the shuttle according to the present embodiment) even in the case where the above-described stacked state of the wing is formed. Since the angle [theta] 3) of the cock 1 is 0 [deg.], The angle formed by the long axis of the shaft and the radial direction of the base body (the angle [theta] 1 of the shuttlecock 1 according to the present embodiment) should be larger than ± 5 [deg.]. Thus, the above-described laminated state of the wings is formed. Therefore, when such a shuttlecock is caused to fly, an air flow different from that of the wing portion 5 is generated by the shaft 7 (wing shaft portion 8), and the rotational force due to the air flow in the shaft 7 (wing shaft portion 8) is the wing portion. 5 occurs in a direction that cancels the rotational force generated by the air flow at 5. As a result, it has been difficult for conventional shuttlecocks to achieve the same flight characteristics as natural shuttlecocks. Details will be described in an embodiment described later.

  The side surface shape of the shaft 7 in the present embodiment is warped when viewed from the side surface as shown in FIG. 7, but other shapes may be employed. For example, referring to FIG. 9, the shape may be such that when viewed from the side surface of the shaft 7, the shaft 7 extends straight without warping.

  As shown in FIG. 4, the wing portion 5 according to the present embodiment has areas on the main surfaces 5A and 5B of a region 5L located on the left side and a region 5R located on the right side with respect to the shaft 7 (fixed shaft portion 10). Are provided equally (provided symmetrically with respect to the shaft 7), but is not limited thereto. The region 5L and the region 5R may be provided so that one of them has a larger area than the other on the main surfaces 5A and 5B, that is, asymmetric with respect to the shaft 7 (fixed shaft portion 10). Good. In this case, for example, as shown in FIG. 13, the region 5L of one wing portion 5 is located on the outer peripheral side of the region 5R, and the region 5L of one wing portion 5 of the adjacent artificial feather 3 is the other wing portion 5. When the region 5R is located on the outer peripheral side and is arranged so as to partially overlap with the region 5R, the region 5L is provided to have a larger area than the region 5R as shown in FIG. Is preferred. Conversely, the region 5R of one wing portion 5 is positioned on the outer peripheral side of the region 5L, and the region 5R of one wing portion 5 of the adjacent artificial feather 3 is positioned on the outer peripheral side of the region 5L of the other wing portion 5. And when it arrange | positions so that it may overlap with this partially, it is preferable that the area | region 5R is provided so that it may become a larger area than the area | region 5L. In this way, the air resistance of the shuttlecock 1 can be increased, the speed reduction performance can be improved, and the flight characteristics equivalent to those of the natural shuttlecock can be realized. In fact, it has been confirmed that the buoyancy of the shuttlecock 1 also increases in wind tunnel experiments. Moreover, when both the area | region 5R and area | region 5L of the wing | blade part 5 are provided large, the mass of the shuttlecock 1 will increase except the case where the material which comprises the wing | blade part 5 is sufficiently light. Further, when the area located on the outer peripheral side of the shuttlecock 1 is smaller than the area located on the inner peripheral side, the number of revolutions when the shuttlecock 1 flies becomes too high, for example, 600 rpm or more and 700 rpm or less. There arises a problem that the characteristics are not stable.

  The cross-sectional shape perpendicular to the extending direction of the shaft 7 in the present embodiment has a rectangular shape as shown in FIG. 5, but is not limited thereto. The cross-sectional shape of the shaft 7 may have an arbitrary shape as long as it has the long axis L and the neutral axis N. For example, referring to FIG. 10, the cross-sectional shape perpendicular to the extending direction of shaft 7 may be a cross shape. The cross shape here refers to a shape in which the length along the long axis L is longer than the length along the neutral axis N. Even in this case, the cross section of the shaft 7 has the major axis L and the neutral axis N extending perpendicularly to the major axis L. At this time, the long axis L and the neutral axis N may be formed so as to pass through the cross-shaped protruding portion. Therefore, the insertion hole provided on the fixing surface portion of the base body 2 is provided so that the shaft 7 can be inserted, and when the base portion of the shaft 7 is fitted to the base body 2, the long axis of the shaft 7 is provided. If the angle θ1 formed by L and the radial direction D of the base body 2 is set to ± 5 degrees or less, the rigidity of the shaft 7 in the radial direction D can be increased. Moreover, the shuttlecock obtained in this way can increase the rotational speed by applying a large rotational force when flying, and can realize the flight characteristics equivalent to those of a natural shuttlecock. That is, even if the cross-sectional shape perpendicular to the extending direction of the shaft 7 is a cross shape, the same effect as the shuttlecock 1 according to the present embodiment can be obtained.

  For example, referring to FIG. 11, the shape of the cross section perpendicular to the extending direction of shaft 7 may be an I-shape. Here, the I-shape refers to a shape in which protruding portions that protrude from both ends in the major axis direction of the rectangular shape to both sides in the minor axis direction are formed. Even in this case, the cross section of the shaft 7 has the major axis L and the neutral axis N extending perpendicularly to the major axis L. Therefore, the insertion hole provided on the fixing surface portion of the base body 2 is provided so that the shaft 7 can be inserted, and when the base portion of the shaft 7 is fitted to the base body 2, the long axis of the shaft 7 is provided. The shuttlecock in which the angle θ1 formed by L and the radial direction D of the base body 2 is set to ± 5 degrees or less can provide the same effects as the shuttlecock 1 according to the present embodiment.

  For example, referring to FIG. 12, the shape of the cross section perpendicular to the extending direction of shaft 7 may be a U-shape. Here, the U-shape refers to a shape in which a protruding portion that protrudes from one end in the short axis direction from both ends in the long axis direction of the rectangular shape is formed. If it says from a different viewpoint, the shape of the said cross section of the axis | shaft 7 may have the shape where the axis | shaft 7 was divided | segmented along the long axis L of I shape. Even in this case, the cross section of the shaft 7 has the major axis L and the neutral axis N extending perpendicularly to the major axis L. Therefore, the insertion hole provided on the fixing surface portion of the base body 2 is provided so that the shaft 7 can be inserted, and when the base portion of the shaft 7 is fitted to the base body 2, the long axis of the shaft 7 is provided. The shuttlecock in which the angle θ1 formed by L and the radial direction D of the base body 2 is set to ± 5 degrees or less can provide the same effects as the shuttlecock 1 according to the present embodiment. In addition, in the axis | shaft 7 shown in FIGS. 10-12, the length W2 of a short side does not need to be constant in the extension direction of the axis | shaft 7, and may be provided so that it may change.

  Here, although there is a part which overlaps with embodiment mentioned above, the characteristic structure of this invention is enumerated.

  A shuttlecock 1 according to the present invention includes a hemispherical base body 2 and a plurality of artificial feathers 3 connected to the base body 2, and the artificial feather 3 includes a wing part 5 and a wing part 5. The wing portion 5 and the shaft 7 include the connected shafts 7, and the main surfaces 5A and 5B, which are surfaces having a relatively large area in the wing portion 5, are perpendicular to the extending direction of the shaft 7. Are fixed so as to be inclined with respect to the neutral axis N at which the cross-section secondary moment is maximum, and the respective shafts 7 of the plurality of artificial feathers 3 are annularly arranged on the surface of the base body 2. The angle formed by the neutral axis N of the shaft 7 and the radial direction extending from the center 12 of the region where the shaft 7 is annularly arranged toward the shaft 7 is not less than 85 degrees and not more than 95 degrees.

  In this way, the shuttlecock 1 receives the greatest force in the radial direction D of the base body 2 when the racket is hit, but the shaft 7 in the radial direction D has high rigidity, so Can be kept small. As a result, the load applied to the wing part 5 and the string-like member 14 with the deformation of the shaft 7 can be reduced, and the durability of the shuttlecock 1 can be enhanced. Further, since the durability of the shaft 7 can be increased without increasing the thickness of the shaft 7 of the artificial feather 3, the overall mass of the shuttlecock 1 is not increased, and the weight of the shuttlecock 1 and the shaft 7 are reduced. It is possible to achieve both improved durability.

  The angle formed by the main surfaces 5A and 5B and the neutral axis N is preferably 15 degrees or greater and 45 degrees or less. In this way, even if the angle θ1 formed by the long axis L of the shaft 7 and the radial direction D is provided to be ± 5 degrees or less, the adjacent wing portions in the plurality of artificial feathers 3 It is possible to form a state in which the five are partially laminated with a certain relationship. Therefore, compared with a conventional shuttlecock in which the angle θ1 is outside the numerical range and the angle θ3 is 0 degrees (that is, the main surface 5A of the wing 5 and the neutral axis N of the shaft 7 are parallel), A large air flow can be formed in a certain direction around the shuttlecock 1.

  In the cross section, the shape of the cross section of the shaft 7 may be rectangular. In this way, the cross section of the shaft 7 has the long axis L and the neutral axis N extending perpendicularly to the long axis L, so that the rigidity of the shaft 7 in the radial direction D can be increased.

  In the cross section, the shape of the cross section of the shaft 7 may be an I shape. Even in this case, since the cross section of the shaft 7 has the long axis L and the neutral axis N extending perpendicularly to the long axis L, the rigidity of the shaft 7 in the radial direction D can be increased.

  In the cross section, the shape of the cross section of the shaft 7 may be a U shape. Even in this case, since the cross section of the shaft 7 has the long axis L and the neutral axis N extending perpendicularly to the long axis L, the rigidity of the shaft 7 in the radial direction D can be increased.

  In the cross section, the cross section of the shaft 7 may have a cross shape. Even in this case, since the cross section of the shaft 7 has the long axis L and the neutral axis N extending perpendicularly to the long axis L, the rigidity of the shaft 7 in the radial direction D can be increased.

  The wing portion 5 may be asymmetrical with respect to the shaft 7. In this way, the air resistance of the shuttlecock 1 can be increased, the speed reduction performance can be improved, and the flight characteristics equivalent to those of the natural shuttlecock can be realized.

  Next, examples of the present invention will be described.

  The inventors of the present application conducted the following experiment in order to confirm the effect of the shuttlecock 1 according to the embodiment.

<Experiment 1: Rotational speed evaluation of shuttlecock>
A shuttlecock using artificial feathers according to an embodiment of the present invention and two types of shuttlecocks as comparative examples are prepared, air is blown from below the cylinder by a blower, the shuttlecock is floated and rotated, and contactless rotation is performed. The rotational speed (number of rotations) of the shuttlecock was measured using a number measuring device. Specifically, a reflection mark was attached to the side surface of each base body, and the number of rotations was measured by irradiating the side surface of the base body of the shuttlecock with red visible light while floating the shuttlecock in a transparent acrylic cylinder.

(sample)
Five shuttlecocks 1 using the artificial feathers 3 shown in FIGS. 1 to 8 were prepared as samples of the examples of the present invention.

  Specifically, the base body 2 is provided with 15 rectangular insertion holes in an annular shape, and when the base portion of the shaft 7 is fitted into each insertion hole, the long axis L of the shaft 7 and the base An object having an angle θ1 formed by the radial direction D of the body 2 of 0 degrees was prepared. The artificial feather 3 has a shaft 7 with a length W1 (see FIG. 5) of 2.3 mm, a length W2 of 0.7 mm, and an angle θ3 formed between the main surface 5A of the wing 5 and the neutral axis N of the shaft 7. A 30 degree thing was prepared. A total of 15 artificial feathers 3 were connected and fixed to the respective insertion holes of the five base bodies 2, and five example shuttlecocks having the same configuration were prepared.

  The material constituting the base body 2 was natural cork, EVA (ethylene vinyl acetate copolymer), polyurethane (PU synthetic leather), PVC (polyvinyl chloride), polyethylene, and polypropylene. The material constituting the shaft 7 was uniaxially stretched polyethylene terephthalate. Polyethylene foam was used as the material constituting the shaft fixing layer 91 and the foam layer 92 of the wing 5, and double-sided tape was used as the adhesive layers 93 and 94.

  Moreover, five shuttlecocks comprising the following base body and artificial feathers were prepared as comparative samples.

  Specifically, the base body is provided with 15 rectangular insertion holes in an annular shape, and the long axis of the shaft and the radial direction of the base body when the base portion of the shaft is fitted into each insertion hole. The one with an angle θ1 formed by 15 degrees was prepared. The artificial feather has a shaft body length W1 (see FIG. 5) of 2.3 mm, a length W2 of 0.7 mm, and an angle θ3 formed by the main surface of the blade and the neutral axis N of the shaft is 0 degree. I prepared a thing. Fifteen comparative example shuttlecocks having the same configuration were prepared by connecting and fixing a total of fifteen artificial feathers to each insertion hole of the five base bodies.

  For each sample, the angle θ1 formed by the long axis L of the shaft 7 and the radial direction D of the base body 2 when the root portion of the shaft 7 was fitted in each insertion hole was measured by the following method. . First, the shaft 7 of the shuttlecock (finished product) was cut at a position on the surface of the fixed part of the base body 2 and inserted into a jig so that the surface of the fixed part of the base body 2 was horizontal. Next, the surface of the fixed portion of the base body 2 and the cross section of the shaft 7 are photographed with a camera from above, and the obtained photographed image is taken into the CAD, and the outer periphery of the base body 2 and the cross section of the shaft 7 are traced. The centroid of section 7 was calculated by CAD and plotted. Next, a radius passing through the centroid of the cross section of the shaft 7 from the center 12 of the base body 2 was drawn, and an angle formed by the major axis L of the cross section of the shaft 7 and the radius (radial direction D) was measured. The center 12 of the base body 2 is provided with a cross-shaped marking on the surface of the jig, for example, so as to overlap the center 12 of the base body 2 when the base body 2 is inserted into the jig. By taking pictures including scribing, we identified them from scribing images. The angle formed by the neutral axis N of the shaft 7 and the radial direction D can be obtained by calculating and plotting the angle of the principal axis of the cross-sectional secondary moment in the cross section of the shaft 7 using CAD.

  The angle θ3 formed between the main surface 5A of the wing 5 and the neutral axis N of the shaft 7 was determined by the following method. First, referring to FIG. 14, a measurement jig capable of fixing the wing portion 5 without contacting the shaft 7 was prepared. Specifically, the main surfaces 5A and 5B of the wing part 5 that do not contact the shaft 7 (fixed shaft portion 10) and extend from the fixed shaft portion 10 to the left and right in a direction perpendicular to the extending direction of the shaft 7; A measurement jig provided with a pedestal 52 and an indenter 53 provided so as to be able to contact each other was prepared. Next, the main surfaces 5A and 5B of the wing part 5 were sandwiched between the pedestal 52 and the indenter 53, an image of the artificial feather 3 was acquired from the extending direction of the shaft 7, and the angle θ3 was obtained by image processing.

(Evaluation)
About the shuttlecock of each sample, air was flowed from the lower part of the cylinder by a blower at 7 m / second, the shuttlecock was floated and rotated, and the number of rotations of the shuttlecock was measured using a non-contact rotation number measuring device. For the measurement, five shuttlecocks were prepared for each sample, and the average number of rotations of the five was calculated. A digital tachometer (HT-4100 manufactured by Ono Sokki Co., Ltd.) using red visible light was used as the non-contact rotation number measuring device.

(result)
The measurement results are shown in Table 1.

  As shown in Table 1, the average number of revolutions of each sample of the example was 407 rpm. The flight trajectory of the shuttlecock was also relatively close to that of the natural shuttlecock.

  On the other hand, the average number of revolutions of each sample of the comparative example was 171 rpm. That is, it was confirmed that the number of rotations of the shuttlecock of the example was increased more than double that of the shuttlecock of the comparative example. In addition, due to such a difference in the number of revolutions, the trajectory at the time of flight of the shuttlecock of the comparative example is different from the trajectory at the time of flight of the shuttlecock of the embodiment, and is different from the trajectory at the time of flight of the natural shuttlecock. It was. In addition, when the rotation speed was less than 300 rpm, the shuttlecock easily sways during flight, and the locus during flight tended to be unstable.

<Experiment 2: Sensory test>
With respect to the shuttlecock as an example and a comparative example used in Experiment 1, a batting test was performed, and a sensory evaluation was performed by a tester.

(result)
The evaluation results are shown in Table 2.

  It was confirmed that the shuttlecock of the example did not feel uncomfortable with the natural shuttlecock using waterfowl feathers for high clear and lob, and had flying characteristics equivalent to the natural shuttlecock. On the other hand, the shuttlecock of the comparative example has a natural trajectory even when hitting with the intention of high clearing, and the trajectory extends when it hits with the intention of a lob. It had different flight characteristics from the cock.

  In addition, the shuttlecock of the example felt that the smash had a slightly lower speed reduction performance than the natural shuttlecock, but had a higher speed reduction performance than the shuttlecock of the comparative example.

  As for the shuttlecock of the comparative example, the rotational speed is low as confirmed in Experiment 1, so that the straight running stability is low and the deceleration performance is insufficient. As a result, it is considered that the flight distance increases beyond the intended flight distance. On the other hand, the shuttlecock of the example can achieve a high rotational speed as confirmed in Experiment 1, and therefore has high straight running stability and high deceleration performance compared to the shuttlecock of the comparative example. it seems to do.

  In addition, the sample of an Example showed sufficient durability, without generating shape collapse during the test of Experiment 2.

  As described above, it has been found that the shuttlecock of the example according to the present embodiment has a flight characteristic closer to that of a natural shuttlecock than the conventional shuttlecock and exhibits sufficient durability.

  The embodiments and experimental examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly advantageously applied to a shuttlecock provided with artificial feathers.

  1 Shuttle cock, 2 base body, 3 artificial feathers, 5 wings, 5A, 5B main surface, 5L, 5R region, 7 axes, 8 wing shafts, 8a, 8b side surface, 10 fixing shafts, 12 centers, 14 strings 15 member, 15 middle thread, 52 pedestal, 53 indenter, 91 shaft fixing layer, 92 foam layer, 93, 94 adhesive layer.

Claims (7)

A hemispherical base body;
A plurality of artificial feathers connected to the base body,
The artificial feather includes a wing part and a shaft connected to the wing part,
In the wing portion and the shaft, the main surface, which is a surface having a relatively large area in the wing portion, has a maximum secondary moment in a cross section of the shaft perpendicular to the extending direction of the shaft. It is fixed to tilt with respect to the vertical axis,
Each of the shafts of the plurality of artificial feathers is annularly arranged on the surface of the base body,
The shuttlecock, wherein an angle formed by the neutral axis of the shaft and a radial direction extending from the center of a region where the shaft is annularly arranged toward the shaft is 85 degrees or more and 95 degrees or less.   The shuttlecock according to claim 1, wherein an angle formed by the main surface and the neutral axis is not less than 15 degrees and not more than 45 degrees.   The shuttlecock according to claim 1 or 2, wherein a shape of the cross section of the shaft is a rectangular shape.   The shuttlecock according to claim 1 or 2, wherein a shape of the cross section of the shaft is an I-shape.   The shuttlecock according to claim 1 or 2, wherein a shape of the cross section of the shaft is a U-shape.   The shuttlecock according to claim 1 or 2, wherein a shape of the cross section of the shaft is a cross shape.   The shuttlecock according to any one of claims 1 to 6, wherein the wing portion is asymmetrical with respect to the axis.

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