JP3382464B2 - Swimming cap - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reducing the resistance of a swimming cap, and more particularly to a swimming cap that reduces the resistance a swimmer receives from water in a swimming competition and helps improve records.

[0002]

2. Description of the Related Art In a swimming competition for 1/100 second,
Record improvement is the fight against water resistance. The ratio of the resistance of the head occupying in it is large, and the resistance of the swimming cap is large, which affects the recording. Conventionally, as a means for reducing the resistance of a swimming cap, a non-water-flow rectifying sheet having fine ridges formed parallel to the flow of water is attached to the surface of the swimming cap. 4-44313). Moreover, the technique of providing fine projections on the entire surface of the swimming cap was also used.

[0003]

The total resistance a swimmer receives in a swimming competition is regarded as the sum of surface friction resistance, shape resistance and wave-making resistance. Among them, the effect of the swim cap is the surface friction resistance. And shape resistance (pressure resistance), and most of them are said to be shape resistance. The mechanism of shape resistance generation is shown in FIG. The flow of water flowing near the head during swimming collides with the crown 7 and flows toward the occipital region 8 along the surface of the head. The water flow flowing along the surface of the head flows backward while exerting pressure on the head, but the pressure decreases from the crown 7 to the occipital region 8, and when the pressure exceeds the most bulged apex 10 of the occipital region 8, the pressure increases. Will increase. In the vicinity of the top 10, the water flow along the surface of the head causes separation at the separation point 9a, and a vortex 11 is generated behind the head to serve as resistance. This resistance is a so-called shape resistance. On the other hand, in order to prevent separation of the water flow flowing on the surface of the object in running water and reduce the shape resistance,
In general fluid dynamics, a method of forcibly disturbing the water flow near the surface of an object to make it turbulent and making it difficult to separate from the surface of the object is recognized in general fluid dynamics. A method has also been proposed in which the water flow near the surface of an object is rectified in the direction of flow to reduce the surface frictional resistance.

As a means for reducing the resistance of the swimming cap, there is the above-mentioned Japanese Utility Model Publication No. 4-44313. The rectifying effect can be expected to some extent, but the effect of reducing the shape resistance cannot be expected. In addition, some of the swimming caps with fine protrusions on the entire surface have some protrusions that contribute to the reduction of the shape resistance, but there are also protrusions that do not contribute to the reduction of the shape resistance. Therefore, there is a problem that the surface friction resistance is increased.

[0005]

The swimming cap according to the present invention has a group of protrusions formed by independent fine protrusions on the surface of the body of the cap made of an elastic material as the most effective portion. By providing it in the most effective form, the water flow flowing on the surface of the swimming cap is disturbed into a turbulent flow, and the shape resistance is reduced without retreating the separation position of the water flow and increasing the surface friction resistance. .

As shown in FIG. 5, the projections constituting the projection group are arranged in a zigzag pattern, and the laminar flow of water flowing on the surface of the swimming cap is changed to turbulent flow, whereby the occipital region of the cap is changed. Water flow separation that occurs in the vicinity can be moved backward. Furthermore, the turbulent flow can be generated more effectively by arranging the protrusions forming the protrusion group in a zigzag pattern with respect to the front-back direction of the swimming cap or the direction of the water flow. That is, the water flow flowing on the surface of the projection group hits the projections in the first row and flows backward while disturbing the flow.
Water flow is disturbed more flow in the first row of projections, Yuku further flows rearward disturbed flow by the second row of projections arranged in a zigzag manner respectively to each projection of the first row . Since the protrusions forming the protrusion group are arranged in a zigzag manner in this manner, the water flow flowing on the surface of the swimming cap can be effectively disturbed and turbulent flow can be generated.

As described above, by providing the projection on the surface of the swimming cap, a turbulent flow is generated on the surface of the cap, and the vortex generated behind the head is reduced by retracting the separation position of the water flow to reduce the shape resistance. On the other hand, the friction resistance of the surface can be increased while reducing the friction coefficient. Therefore, the density of the projections represented by the distance between the projections forming the projection group, and the height, diameter, shape, etc. of each projection were optimized by experiments.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION That is, the swimming cap according to the present invention has a group of protrusions formed by independent fine protrusions on the surface of the body of the cap made of a stretchable material such as silicone, polyurethane and various rubbers. It is implemented by providing.

The swimming cap body is made of the above highly elastic material, has a thickness of about 0.3 mm to 1.5 mm, is substantially uniform, and is formed to have a shape similar to a human head. As shown in FIGS. 2 and 4B, the projection group 4a
Is the back head 8 of the body of the swimming cap 3,
A width of about 3 from the lower part of the most bulged apex 10 of the occipital region or the slightly lower part of the most bulged apex 10 of the occipital region
It is provided in the area of 0.0 mm to 50.0 mm. In this case, the protrusions are arranged from the center point A of the bottom of the swimming cap shown in FIG. 2 to the back of the cap along a line forming an angle of about 25 ° to 30 ° with the bottom. To form.

As shown in FIGS. 4 (b) and 5, the projections 4 constituting the projection group 4a are arranged in a staggered pattern with respect to the flow of water during swimming. Further, the respective projections forming the projection group can be arranged in a zigzag shape when viewed from the front to the rear. By arranging the protrusions forming the protrusion group in a zigzag manner in this manner, it is possible to more effectively change the laminar flow of water flowing on the surface of the swimming cap into a turbulent flow. The separation point 9b of the water stream generated in the vicinity can be moved rearward as compared with the separation point 9a. As a result, the generation of the vortex 11 generated in the rear is suppressed, which contributes to the reduction of the shape resistance.

Next, in order to optimize the density of the protrusions represented by the distance between the protrusions forming the protrusion group, and the height, diameter, shape, etc. of the protrusions, an experiment was conducted using the apparatus shown in FIG. went. That is, the human head model 6 is fixed to the column 5 having the dynamic strain gauge 7 at an appropriate angle. The manipulator model 6 is covered with a swimming cap 3 formed by variously changing the intervals, heights, diameters and shapes of the protrusions, and the manipulator model 6 is submerged to an appropriate depth in the running water channel and is hung on the manipulator model 6. The total resistance is measured by the dynamic strain gauge 7 via the column 5. The flow velocity was set to about 1.4 m / s to 2.0 m / s, which is the swimming speed of the athlete in the swimming competition.

As a result, it is preferable that the distance between the protrusions constituting the protrusion group is 3.0 mm to 10.0 mm.
It was found that about 0 mm was optimal. Further, it was found that the height of the protrusion is preferably 0.5 mm to 2.0 mm, and optimally about 1.0 mm. In this case, the height of all the protrusions may be the same, or the height may be changed for each portion where the protrusion is provided. However, if the height of the protrusion is less than 0.5 mm, turbulent flow cannot be expected. On the other hand, if it exceeds 2.0 mm, the frictional resistance of the surface of the swimming cap becomes too large, and the turbulent flow causes resistance to shape. Will be offset. Furthermore, regarding the diameter of the protrusion, 0.5 mm to 2.
It was found that 0 mm is suitable, and about 1.0 mm is optimum. The shape of each protrusion is preferably a hemispherical shape, a conical shape, a truncated cone shape, a cylindrical shape, or a shape in which a circular cylinder and a hemisphere are combined.

The protrusion according to the present invention is made of synthetic resin such as silicone, polyurethane, polyvinyl chloride, nylon, polyester, polyethylene, polypropylene, or natural rubber or synthetic rubber. It is formed by a method of integrally molding by a dipping manufacturing method. In addition, as another manufacturing method, the projections formed in advance are bonded to the surface of a stretchable substrate with an adhesive or the like, or the screen printing method or gold is directly applied to the surface of the stretchable substrate. It is also possible to integrally form them using a mold by an injection manufacturing method, a thermoforming method, or a high frequency bonding method.

[0014]

EXAMPLE A swimming cap according to the present invention is implemented by the following method. As shown in FIG. 1, in an aluminum die 1 for dipping molding, a diameter of 1.0 mm and a depth of 1.0 along a line forming an angle of about 25 ° from the center position A of the die bottom to the back of the cap. mm hemispherical hole 2
With the distance between the centers of the holes 2 at 6.0 mm and the arc B of the mold.
Five pieces are dug from C to the center position A. next,
On the circular arc BC, two rows of holes 2 are dug at a distance of 8.0 mm toward B in a zigzag pattern with the holes previously formed to form a mold. Next, the mold 1 is dipped in the natural rubber emulsion solution, pulled up, and then dried. After drying, the cap is removed from the mold, and when the front and back are returned, the swimming cap 3 shown in FIG. 2 is formed in which the protrusion 4 is formed at the portion corresponding to the hole 2 of the mold.

The swimming cap formed in this manner is used as an invention product, and a similar swimming cap having no protrusion is used as a comparison product. These swimming caps were put on a human head model using a device as shown in FIG. 3, the resistance applied to the entire human head model was measured in running water of 1.8 m / s, and the resistance coefficient at that time was calculated. As a result, the invention product had a lower 1.0% resistance than the comparison product.

[0016]

The swimming cap according to the present invention is constructed as described above and has the following effects. That is, on the surface of the body of the cap made of a stretchable material, a group of protrusions composed of independent fine protrusions,
By providing the most effective part in the most effective form, the effect of reducing the shape resistance can be achieved while the increase of the frictional resistance on the surface is minimized.

In particular, by arranging the protrusions constituting the protrusion group in a zigzag manner, the laminar flow of water flowing on the surface of the swimming cap is effectively changed to turbulent flow, thereby occupying the back of the cap. Water flow separation that occurs in the vicinity can be moved backward. Therefore, the backward vortex generated by the separation of the water flow can be reduced to a minimum, and the effect of reducing the resistance received by the athlete wearing the swimming cap according to the present invention can be achieved, which in turn contributes greatly to the improvement of the competition record. To do.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a mold used for a dipping manufacturing method of a swimming cap according to the present invention.

FIG. 2 is a side view of a swimming cap according to the present invention.

FIG. 3 is a schematic view of an apparatus for measuring the resistance applied to a swimming cap.

FIG. 4 is a diagram showing a state in which a water flow is separated near the back of a swimmer's occipital region and a vortex is generated in the rear, (a) shows a conventional swimming cap, and (b) relates to the present invention. It is the figure which showed the swimming cap.

FIG. 5 is a conceptual diagram showing a state of water flow flowing between the protrusions provided in a zigzag manner on the surface of the swimming cap according to the present invention.

[Explanation of symbols]

1 mold 2 holes 3 swimming caps 4 protrusions 4a protrusion group 5 props 6 human head model 7 Dynamic strain gauge 8 occipital region 9a Peeling point 9b Peeling point 10 summit 11 vortex

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-99309 (JP, A) Fukukaihei 6-12419 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A42B 1/12 A41D 7/00

Claims (6)

(57) [Claims] 1. A swimming cap made of a stretchable material, comprising:
A group of protrusions composed of independent fine protrusions, with the most bulge of the occipital region or the most bulge of the occipital region
Width approximately 30.0 mm to 50.0 from the lower part of the top toward the bottom
mm area and at the bottom of the swimming cap
Angle from the center point to the back of the cap about 25 ° to 30 ° to the bottom
A swimming cap characterized by being formed along a line that forms a degree . 2. The swimming cap according to claim 1, wherein the protrusions forming the protrusion group are provided with protrusions arranged in a zigzag pattern. 3. The swimming cap according to claim 1, wherein the protrusions forming the protrusion group are provided with protrusions arranged in a zigzag pattern in the flow direction. 4. The swimming cap according to claim 1, wherein the projections forming the projection group are provided with a projection group arranged in a zigzag pattern in the front-back direction of the swimming cap. 5. The distance between the protrusions forming the protrusion group is
Swimming cap according to any one of claims 1 to 4, characterized in that a 3.0 mm~10.0mm. 6. The height of each protrusion forming the protrusion group is 0.
Swimming cap according to any one of claims 1 to 5, characterized in that a 5 mm~2.0 mm.