JP6998074B2 - Flippers - Google Patents

Description

The present invention relates to flippers used during swimming.

In snorkeling, scuba diving, underwater work, etc., swimmers wear flippers for propulsion.

Some of such flippers are provided with holes (hereinafter referred to as jet holes) penetrating the front and back sides in order to obtain further propulsive force (for example, Patent Document 1).

U.S. Pat. No. 3,183,529

Fluids such as water and air have the property of being attracted and sticking when they come into contact with the surface of an object, and this property is called the Coanda effect. When an object has a smooth shape, the fluid sticks to the object due to the Coanda effect and flows along the smooth shape.

Hereinafter, the flippers of the conventional configuration in which the fluid is taken into the jet hole based on the Coanda effect will be described. FIG. 8 is a perspective view of a conventional flipper, showing a surface that can be visually recognized when a user wearing the flipper walks in water or on land. This surface is referred to here as a "front surface" (surface). 9 is a perspective view showing the opposite surface (hereinafter referred to as “back surface”) of the flipper 100A shown in FIG. 8, and FIG. 10 shows the flippers in the posture with the back surface facing up as shown in FIG. It is a cross-sectional view of 100A. Further, the directions of the X-axis, the Y-axis, and the Z-axis shown in each drawing are the same, and "forward" and "rear" are indicated with reference to the propulsion direction when swimming with a fluttering foot or the like. If necessary, the horizontal direction and the vertical direction are also shown in each drawing.

In the posture of the flipper 100A shown in FIG. 8, the user inserts the toe into the foot pocket 50A which is the opening of the foot fitting portion 50, and adjusts the length of the strap (not shown) attached to the fixing portion 50B by himself / herself. Adjust to fit your ankle size. As a result, the user wears the flippers 100A.

When a user wearing a flipper 100A swims with a fluttering foot or the like, the user (= swimmer) usually swims in a posture in which the belly is on the lower side and the back is on the upper side. Such a posture of the user is referred to as a "swimming posture" here. When the user is in a swimming posture, the flipper 100A has the back surface on the upper side (upper surface) and the front surface on the lower side (lower surface) as shown in FIGS. 9 and 10.

As shown in FIG. 10, the flipper 100A has a jet hole 10 which is a hole penetrating from the front surface to the back surface of the flipper 100A so as to partition the blade 60 which is a webbing portion and the foot fitting portion 50. It is provided. As shown in FIGS. 8 and 9, the jet hole 10 illustrated here is divided into three parts in the left-right direction (X-axis direction) by the keel 11, but the embodiment is not limited to this. ..

The jet hole 10 is provided so that the opening 10A on the front surface 60A side is in front of the opening 10B on the back surface 60B side in the propulsion direction. The opening 10A on the front surface 60A side is open so as to face the foot fitting portion 50 located in the front, and the opening 10B on the back surface 60B side faces the blade 60 located in the rear. It is open.

The advantage of providing the jet hole 10 having such a configuration will be described with reference to FIG.

When the user wears the flippers 10A and swims with a fluttering foot or the like, turbulence (Karman vortex) is generated at 60B on the back surface as the blade 60 moves up and down in the water. Therefore, the upper part of the back surface 60B (upper surface of the blade) of the blade 60 becomes a negative pressure due to the operation of strongly moving the foot downward by the fluttering foot (hereinafter referred to as “kick operation”), so that the turbulent flow is on the negative pressure side. It tends to be attracted and stay on top of the back surface 60B of the blade 60. As described above, when a turbulent flow is generated and stays in the vicinity of the blade 60, the propulsive force is attenuated.

In order to alleviate the damping of the propulsive force, the flippers 100A are provided with a jet hole 10 which is a hole penetrating the blade surface from the front and back. The jet hole 10 takes in the surrounding water from the opening 10A and entrains it in the hole during the kicking operation by the fluttering foot. As a result, a jet water flow is generated from the front surface 60A toward the back surface 60B. This jet water flow pushes the turbulent flow remaining on the back surface 60B side to the rear side due to the Coanda effect and removes it, so that the influence of the turbulent flow can be reduced and the damping of the propulsive force can be alleviated.

However, in the conventional configuration of the flippers 100A, the water caught in the jet hole 10 diffuses immediately after being discharged from the opening 10B, so that the Coanda effect is attenuated and separated from the object surface, and the turbulent flow is efficiently performed. Cannot be swept backwards.

Therefore, an object of the present invention is to provide a technique for increasing the propulsive force when swimming with flippers in order to solve the above-mentioned problems of the prior art.

The flippers according to the present invention for solving the above problems are attached to the user's foot and are provided with through holes penetrating the front and back to allow fluid to flow from the front to the rear in the propulsion direction when the user is swimming. A flipper, which is a protrusion provided on the bottom surface of the through hole when the back surface of the flipper is turned upward. The end is located inside the through hole and extends backward from the end. It is characterized by having a protrusion provided so as to.
Further, the above-mentioned protrusion is characterized in that it has a shape in which the thickness increases toward the rear.
A plurality of the above protrusions are provided side by side in the left-right direction of the flippers, and the rear end of the protrusion located on the outside in the left-right direction is located behind the rear end of the protrusion located on the inside. It is characterized by that.
Further, the above-mentioned protrusion is characterized in that it is an integral body that is not separated from the main body of the flipper, but the above-mentioned protrusion is detachably provided on the main body of the flipper. It may be a feature.
In the above-mentioned flippers, the dimensional length of the width of the protrusions in the left-right direction of the flippers is longer than the dimensional length of the thickest thickness of the protrusions.
The protrusion is characterized in that it protrudes from the opening on the rear side of the through hole.
Further, the flippers according to the present invention for solving the above problems are attached to the user's foot and have through holes penetrating the front and back to allow fluid to flow from the front to the rear in the propulsion direction when the user is swimming. A provided flipper, which is a protrusion provided on the same surface as the bottom surface of the through hole when the back surface of the flipper is turned upward, and is a specified length from the opening on the rear side of the through hole. It is characterized in that an end portion is located between the end portion and has a protrusion provided so as to extend in the rearward direction from the end portion.

According to the present invention, it is possible to increase the propulsive force when swimming with the flippers.

It is a perspective view which illustrates the back surface of the flipper of an embodiment. It is a perspective view which illustrates the cross section of the flipper of an embodiment. It is a top view which illustrates the front surface of the flipper of an embodiment. It is a figure which illustrates the cross section of AA'in FIG. It is a figure which illustrates the 1st variation of a protrusion. It is a figure which illustrates the 2nd variation of a protrusion. It is sectional drawing in the case where the protrusion is provided on the rear outside of a jet hole. It is a perspective view which illustrates the front surface of a flipper. It is a perspective view which illustrates the back surface of the conventional flippers. It is sectional drawing of the conventional flipper. It is a schematic diagram explaining the advantage of providing a jet hole.

Hereinafter, the configuration of this embodiment will be described with reference to the drawings. The same reference numerals may be used for the parts having the same functions as the parts described with reference to FIGS. 8 to 11 and the description thereof may be omitted.

Further, as in FIGS. 8 to 11 above, the directions of the X-axis, the Y-axis, and the Z-axis are the same in each of the drawings described below, and the notations of "front" and "rear" are fluttering. It is based on the propulsion direction when swimming in such places. If necessary, the horizontal direction and the vertical direction are also shown in each drawing.

FIG. 1 is a perspective view illustrating the back surface of the flippers 100 of the present embodiment, and corresponds to FIG. 9 described above. Further, FIG. 2 is a perspective view illustrating a cross section of the flippers 100 of the present embodiment, and FIG. 3 is a plan view illustrating a front surface of the flippers 100. FIG. 4 is a diagram illustrating a cross section taken along the line AA'of FIG. 3, and corresponds to FIG. 10 described above.

The flippers 100 are attached to the user's feet in order to increase the propulsive force when the user swims, and in the present embodiment, the flippers 100 are made of a material made of rubber or resin.

The flipper 100 is provided with a jet hole 10 which is a through hole penetrating the front and back of the flipper 100. In the present embodiment, the jet hole 10 is divided into three parts in the left-right direction (X-axis direction) by the keel 11, but the presence or absence of partitions and the number of partitions are not particularly limited.

The jet hole 10 has an opening 10A provided on the side of the front surface 60A and an opening 10B provided on the side of the back surface 60B and located behind the opening 10A in the propulsion direction (FIG. 4). reference). When the kicking motion is performed by the fluttering foot, the jet hole 10 takes in water from the opening 10A (hereinafter referred to as "front opening 10A") and takes in water from the opening 10B (hereinafter referred to as "rear opening 10B"). Discharge from. As a result, the jet hole 10 can generate a jet water flow from the front to the rear in the propulsion direction.

Here, each opening of the jet hole 10 is defined. In the posture of FIG. 4, the cross section of the flow path including the vertical line when a vertical line is drawn from the end P1 in the upward direction and its periphery thereof are referred to as the front opening 10A here. Further, the cross section of the flow path including the perpendicular line when a perpendicular line is drawn from the end portion P2 shown in FIG. 4 toward the back surface 60B and the periphery thereof are referred to as a rear opening portion 10B here. As described above, in the present embodiment, the front opening 10A and the rear opening 10B are defined, but the present invention is not limited to this aspect.

As shown in FIG. 1, on the inner bottom surface of the jet hole 10 when the back surface of the flippers 100 is turned upward, protrusions 12A and 12B are provided side by side in the left-right direction. The protrusions 12A and 12B are provided along the direction of the flow path formed by the jet hole 10. Further, the protrusions 12A and 12B are provided so as to extend in the rearward direction from the end P1 (see FIG. 2 or FIG. 4) of the front opening 10A. In the flippers 100 exemplified in FIGS. 1 to 4, the protrusions 12A and 12B extend to the outside of the jet hole 10 via the rear opening 10B.

Further, as shown in FIGS. 2 and 4, the protrusions 12A and 12B have no thickness at the front end P1 and are flush with the inner surface forming the jet hole 10, but become smoother toward the rear. It has a shape that increases in thickness. With such a shape, the water taken into the jet hole 10 has the surface of the protrusions 12A and 12B and the bottom surface of the jet hole (of the blade 60) provided with the protrusions 12A and 12B due to the Coanda effect. It sticks to the extension surface of the back surface 60B) and flows along a smooth shape. Further, since the side surfaces of the protrusions 12A and 12B are added, the sticking surface in the vicinity of the rear opening 10B can be increased by this amount. As a result, the degree of sticking of the fluid can be increased, and even if the fluid separates from the surface, it does not scatter for a while and maintains the straight progress (the straight progress of the fluid due to the Coanda effect can be maintained for a while). ..

Further, by making the protrusions 12A and 12B thicker toward the rear opening 10B on the exit side of the jet hole 10, the rear opening 10B has a cross section having an uneven shape, and the original cross section (protrusion 12A) is obtained. , The cross section of the rear opening 10B when 12B is not provided) is smaller in area. Therefore, due to the relationship between the flow velocity and the cross-sectional area, the speed of the fluid discharged from the jet hole 10 can be increased as compared with the case where the protrusions 12A and 12B are not provided, and the upper surface of the blade 60 can be increased by fluttering or the like. The turbulent flow (Karman vortex) formed in the vicinity can be swiftly swept backward. Further, by making the thickness of the protrusions 12A and 12B smoothly increase toward the rear, the fluid can be smoothly advanced backward without hindering the movement of the fluid.

In the present embodiment, the protrusions 12A and 12B are provided from the end P1 of the front opening 10A, but the embodiment is not limited to this, and the protrusions 12A and 12B are provided from the middle of the hole of the jet hole 10. It may be provided. That is, the protrusions 12A and 12B may be provided so that the front end is located inside the jet hole 10 and extends in the rear direction from the end. The "inside of the jet hole 10" here includes not only the inside of the hole of the jet hole 10 but also the end portions P1 and P2.

Further, in the present embodiment, as shown in FIG. 1, among the three jet holes 10 arranged in the left-right direction, the central jet hole 10 is not provided with the protrusions 12A and 12B. Is not limited to this, and a protrusion may be provided in the central jet hole 10.

As shown in FIG. 1, the protrusions 12A and 12B extend from the inside of the jet hole 10 to the rear outside of the rear opening 10B. As a result, the Coanda effect of the fluid discharged from the rear opening 10B can be further sustained even after the discharge, and the scattering can be alleviated.

Further, as shown in FIG. 1, the protrusions 12A and 12B are provided side by side in the left-right direction, but the protrusion 12A located on the outside in the left-right direction is in the propulsion direction more than the protrusion 12B located on the inside. In long. In other words, the rear end of the protrusion 12A located on the outer side in the left-right direction is provided so as to be located behind the rear end of the protrusion 12B located on the inner side.

By extending the protrusions 12A located on the left and right outer sides to a distance from the rear opening 10B in this way, the Coanda effect of the fluid discharged from the jet hole 10 can be sustained as compared with the protrusions 12B. It is possible to further maintain the straightness directed to the rear of the fluid. As a result, even if the fluid separates from the blade surface and begins to scatter on the inner side in the left-right direction at an early stage, this scattering can be confined and suppressed from the outside for a while.

It should be noted that not only the outer protrusion 12A but also the inner protrusion 12B may be extended far away from the rear opening 10B, but the rigidity may increase and the bending of the blade 60 may deteriorate. Therefore, in the present embodiment, the inner and outer protrusions have different lengths, and only the outer protrusion 12A is lengthened.

Further, the protrusions 12A and 12B have a flat shape as shown in each drawing. In other words, the length of the width dimension (length in the left-right direction) of the protrusions 12A and 12B is longer than the dimension length of the thickest thickness of the protrusions 12A and 12B.

By forming the protrusions 12A and 12B into a flat shape in this way, the degree of resistance due to the provision of the protrusions 12A and 12B can be alleviated. If a protrusion thick enough to be recognized as standing upright on the surface of the blade 60 is provided, this becomes a wall that hinders the progress of the water flow in the jet hole 10, and conversely, the propulsive force is reduced. Connect. In the present embodiment, in order to eliminate such concerns, the protrusions 12A and 12B have a flat shape.

In the present embodiment, the protrusions 12A and 12B are provided on the back surface 60B side of the blade 60, that is, on the bottom surface side of the jet hole 10 when the back surface of the flippers 100 is turned upward as shown in FIG. Here, if a protrusion is provided on the inner upper surface or the inner side surface of the jet hole 10, the surface of the object to be stuck disappears immediately after passing through the jet hole 10, so that the fluid is separated and the Coanda effect is maintained. I can't. Therefore, in the present embodiment, the protrusions 12A and 12B are provided on the bottom surface of the jet hole 10 which is connected to the back surface 60B of the blade 60 to form the same surface. As a result, the surface to be stuck extends even behind the jet hole 10, and even if the fluid passes through the jet hole 10, it maintains the Coanda effect and sticks to the surface, making it straight to the rear. Can be maintained.

Further, in the present embodiment, the main body portion of the flipper 100 composed of the foot fitting portion 50, the blade 60, and the jet hole 10 and the protrusions 12A and 12B are treated as an integral body to manufacture the flipper 100. Therefore, in principle, the main body of the flippers 100 and the protrusions 12A and 12B are integrated without being separated from each other. On the other hand, the members corresponding to the protrusions 12A and 12B may be attached to the flippers having the jet holes by adhesive or screw tightening so that the user can retrofit them. Some flippers are made of rubber or resin that do not deform even when rowed. For such flippers, a protrusion may be separately prepared and attached or removed at the convenience of the user.

Hereinafter, other variations of the flippers 100 of this embodiment will be illustrated.

FIG. 5 illustrates the first variation, and FIG. 5A shows a perspective view and FIG. 5B shows a sectional view. In the flippers 100 exemplified in FIG. 5, a plurality of protrusions 90A and 90B are arranged side by side in the left-right direction as in the above, but all of the protrusions 90A and 90B are in the propulsion direction (flow path direction of the jet hole 10). ) Are the same length (see FIG. 5 (A)). In the flippers 100 shown in FIG. 5, the effect of confining the scattering of the fluid inside in the left-right direction from the outside is limited, but members having the same shape can be used for all of the protrusions 90A and 90B. Therefore, in the case of a configuration in which the protrusion is removable, the protrusion can be manufactured with one mold.

Further, as shown in FIG. 5B, the protrusions 90A and 90B are from the front opening 10A of the jet hole 10 (or may be in the middle of the hole of the jet hole 10) to the front of the rear opening 10B. It is provided between the above and does not protrude to the outside of the rear opening 10B. That is, the protrusions 90A and 90B are configured to be provided only inside the jet hole 10. As described above, even if the protrusion is provided only on the inside of the jet hole 10, it is possible to provide the straightness and non-diffusion of the jet water flow toward the rear as compared with the conventional configuration in which the protrusion is not provided.

FIG. 6 is a diagram illustrating the second variation, and illustrates the protrusion 91 having a longer width dimension in the left-right direction than the protrusions 12A and 12B shown in FIG. Even in the flippers 100 shown in FIG. 6, the effect of confining the scattering of the fluid inside in the left-right direction from the outside is limited. However, since the protrusions having a width in the flow path direction are installed, the compression rate of the water flow coming out of the jet hole 10 increases and the speed of the water flow increases, so that the output of the Coanda effect can be expected to increase. Further, when the protrusions are made removable, it is necessary to attach a total of four protrusions in the configuration shown in FIG. 1, but in the configuration shown in FIG. 6, only two protrusions are required, so that it takes time and effort to attach and detach the protrusions. It can be reduced.

Although various other variations are expected, in a flipper provided with a through hole penetrating the front and back, a protrusion may be provided on the bottom surface of the through hole when the back surface of the flipper is turned upward. Further, it is sufficient that the end portion of the protrusion portion is located inside the through hole and the protrusion portion is provided so as to extend in the rearward direction from the end portion.

The protrusions 12A, 12B, 91 described above extend along the flow path direction of the jet hole 10 from the inside to the outside of the jet hole 10 with the rear opening 10B interposed therebetween, but are behind the protrusions. The position of the end is not limited to this. For example, as in the example of FIG. 5, the protrusion 90 may be provided from the inside of the jet hole 10 to just before the rear opening 10B. That is, the protrusion may be provided so as to extend in the rearward direction from the inside of the jet hole 10, and the position of the rear end may be inside or outside the jet hole 10.

Alternatively, as shown in the cross-sectional view of FIG. 7, the protrusion may not be provided in the jet hole 10 but may be provided only in the rear outer side of the jet hole 10. That is, the end of the protrusion 92 is provided at any position between the rear opening 10B and the rear by a specified length (length L shown in FIG. 7), and the protrusion extends rearward from the end. A unit may be provided. The "specified length L" here is a design length until it is recognized that the jet water flow that has escaped from the rear opening 10B is no longer affected by the Coanda effect, and is, for example, 10 cm. In the example of FIG. 7, the protrusion is provided within the range of this “specified length L”, in other words, within the range where the surface sticking due to the Coanda effect of the fluid is not a little.

In the case of the example of FIG. 7, the surface sticking due to the Coanda effect of the fluid temporarily declines after coming out of the rear opening 10B, but the degree of surface sticking is caused by the fluid moving backward and approaching the protrusion. Will increase. Therefore, even in the example of FIG. 7, the straightness of the jet water flow toward the rear can be maintained to some extent. Also in the example of FIG. 7, the bottom surface of the jet hole 10 when the back surface of the flippers 100 is turned upward (more correctly, the back surface 60B of the blade 60 forming the same surface as the bottom surface of the jet hole 10). A protrusion 92 is provided.

The protrusions (12A, 12B, 90, 91) described above are all shaped so that the thickness increases toward the rear, and the rear end has the thickest dimension, but the present invention is not limited to this. The shape may be such that the thickness increases toward the rear until the middle, and the thickness does not change from the middle (or the shape becomes thinner from the middle). That is, the protrusion may have a shape in which the thickness increases toward the rear (it is sufficient if the protrusion has a shape in which the thickness increases toward the rear).

In the present embodiment, a configuration has been described in which a flipper is provided on the bottom surface of the jet hole and has a protrusion extending in the rear direction along the flow path direction of the jet hole. By providing such a protrusion, the discharge speed of the fluid from the rear opening can be increased, and the turbulent flow (Karman vortex) can be vigorously pushed backward.

By providing the protrusion as in the present embodiment, the blade surface has a convex or concave shape in the middle of the water flow passing through the holes (jet holes) penetrating the front and back, or from the middle of the water flow to the tip past the exit. As a result, the Coanda effect is sustained and it becomes difficult to peel off from the surface, so that the straightness and non-diffusivity of the water flow can be imparted.

As described above, according to this embodiment, it is possible to increase the propulsive force when swimming with the flippers.

The present embodiment shows an example for embodying the technical thinking of the present invention, and the present invention is not limited to the above description and illustration.

10 Jet holes 10A, 10B Openings 11 Keels 12A, 12B, 90A, 90B, 91, 92 Protrusions 50 Foot fittings 50A Foot pockets 50B Fixed parts 60 Blades 60A Front side 60B Back side 100, 100A Foot fins

Claims (8)

A flipper that is attached to the user's foot and has through holes that penetrate the front and back to allow fluid to flow from the front to the rear in the propulsion direction when the user is swimming.
It is a protrusion provided on the bottom surface of the through hole when the back surface of the flipper is turned upward, and an end portion is located inside the through hole and is provided so as to extend from the end portion in the rearward direction. A flipper characterized by having a raised protrusion. The flipper according to claim 1, wherein the protrusion has a shape that increases in thickness toward the rear. A plurality of the protrusions are provided side by side in the left-right direction of the flippers, and the rear end of the protrusions located on the outside in the left-right direction is located behind the rear ends of the protrusions located on the inside. The flippers according to claim 1 or 2, characterized in that they do. The flipper according to any one of claims 1 to 3, wherein the protrusion is an integral body that is not separated from the main body of the flipper. The flipper according to any one of claims 1 to 3, wherein the protrusion is detachably provided on the main body of the flipper. One of claims 2 to 5, wherein the dimensional length of the width of the protrusion in the left-right direction of the flipper is longer than the dimensional length of the thickest thickness of the protrusion. The flippers described in. The flipper according to any one of claims 1 to 6, wherein the protrusion protrudes from the opening on the rear side of the through hole. A flipper that is attached to the user's foot and has through holes that penetrate the front and back to allow fluid to flow from the front to the rear in the propulsion direction when the user is swimming.
It is a protrusion provided on the same surface as the bottom surface of the through hole when the back surface of the flipper is turned upward, and is between the opening on the rear side of the through hole and the rear by a specified length. A flipper characterized by having an end located and having a protrusion provided to extend from the end in the posterior direction.

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