JP2006240532A - Parachute - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parachute with a high drag coefficient, capable of relieving the shock in opening the canopy, and with good stability. <P>SOLUTION: This parachute includes a canopy 1 which becomes almost hemispheric upon inflation. The canopy 1 is equipped with a canopy skirt part 12 constituting a hemispheric open surface, a canopy top part 11 forming a canopy top, and a canopy central part 13 connecting the canopy skirt part 12 to the canopy top part 11. This parachute uses a fabric with a low permeability rate of air for the canopy skirt part; a fabric with a high air permeability rate for the canopy central part; and a fabric with an intermediate air permeability rate between that of the skirt part and that of the canopy central part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a parachute, and more particularly to a parachute that can be lowered stably.

  Since the parachute composed of the hemispherical umbrella 1 has a large resistance coefficient, the parachute area required for lowering the fallen object at a certain speed or less can be reduced, and the fallen object dropped from the flying object or the flying object can be reduced. Widely used for lowering.

  As shown in FIG. 6, such a parachute includes an umbrella top 11 that forms the top of the hemispherical umbrella 1, an umbrella edge 12 that forms an open surface, and an umbrella that connects the umbrella top 11 and the umbrella edge 12. It has a central portion 13. The suspension rope 3 that supports the suspended object 2 to be decelerated and lowered is connected to the umbrella edge portion 12.

  When the parachute is extended and lowered, flow separation occurs in the vicinity of the umbrella edge 12 of the umbrella 1, thereby generating an irregular flow (wake) with a vortex (see FIG. 6). Since the distance between the wake region and the umbrella body 1 is small, the pressure resistance from the wake region is exerted on the umbrella body 1, and there is a drawback that the swing occurs while the parachute is lowered and it is difficult to descend stably. .

  In order to solve such a problem, various ideas have been conventionally made. That is, in order to change the air flow in the umbrella body 1, a method of providing the hole 4 near the umbrella central portion 13 as shown in FIG. 6, or an extension portion extending from the umbrella edge portion 12 or the umbrella edge portion (FIG. There is known a method in which a slit is provided in the umbrella body 1 to reduce the resistance coefficient in the umbrella 1 and improve the stability (Japanese Patent No. 2743171).

  In general, in order to improve the stability of the parachute, it can be achieved by reducing the resistance coefficient of the parachute. However, if the resistance coefficient is reduced, the descending speed increases, so the umbrella body 1 needs to be enlarged. There is. However, the storage capacity of the parachute is limited and cannot be generally increased in size. That is, a parachute having a large resistance coefficient and good stability is desired.

In addition, the holes or slits as described above are effective for mitigating the impact at the time of opening the umbrella, but when a plurality of parachutes are dropped simultaneously, two or more overlapping parachutes come into contact with each other. At that time, the parachute itself or the suspended object could enter the hole and cause a serious accident. In addition, the hole 5 provided in the vertex part of the umbrella top part 11 performs the effect | action which relieves an umbrella opening impact.
Japanese Patent No. 2743171 JP 2002-12799 A

  An object of the present invention is to solve the above-described problems, that is, to provide a parachute that has a large resistance coefficient, can mitigate an umbrella opening impact, and has good stability.

  In order to solve the above-described problems, a parachute according to the present invention includes an umbrella body that is substantially hemispherical when extended, and the umbrella body forms an umbrella edge portion that forms a hemispherical open surface and a top portion of the umbrella body. A parachute comprising an umbrella top portion, an umbrella central portion connecting the umbrella edge portion and the umbrella top portion, an umbrella cloth having a small air permeability at the umbrella edge portion, and an umbrella having a large air permeability at the umbrella central portion. An umbrella cloth having an air permeability intermediate between the umbrella edge and the umbrella central part is used for the cloth top.

  According to the present invention, by using an umbrella cloth having an intermediate air permeability at the top of the umbrella, the impact at the time of opening the umbrella can be reduced, stability can be improved, and an umbrella having a small air permeability at the umbrella edge. By using cloth, it is possible to improve the air flow and improve the stability, increase the pressure in the umbrella, increase the area on the projection and increase the drag Become. Furthermore, by increasing the air permeability of the central portion of the umbrella, stability can be improved without affecting the impact of opening the umbrella.

  FIG. 1 is a side view of a parachute according to an embodiment of the present invention, and FIG. 2 is a plan view of the parachute of the present invention. As is clear from these figures, the parachute includes a plurality of substantially triangular gores 6. It has a structure in which an umbrella body 1 that is sewn and connected and formed in a hemispherical shape and a suspension rope 3 is connected to an umbrella edge portion 12 of the umbrella body 1.

  FIG. 3 is a plan view of the gore 6 constituting the umbrella body 1 as described above. In the present invention, the umbrella cloth 6a and the umbrella central part 13 having a small air permeability are provided in the parts constituting the umbrella edge 12 in the present invention. Umbrella cloth 6b having a large air permeability in the part constituting the umbrella, and an umbrella having an air permeability intermediate between the air permeability of the umbrella edge part 12 and the umbrella top part 13 in the part constituting the umbrella top part 11 The cloth 6c is used. Such gore 6 is combined by sewing, and the umbrella body 1 is manufactured.

  In the present invention, the stability of the descent is improved by adjusting the air permeability of the portion of the umbrella body 1. That is, an umbrella cloth 6c that normally transmits air to the umbrella top portion 11, an umbrella cloth 6a that does not easily transmit air to the umbrella edge portion 12, and an umbrella cloth 6b that easily transmits air to the umbrella central portion 13 are used. The air permeability is preferably 1.4 to 1.6 at the umbrella central portion and 0 to 0.2 at the umbrella edge when the transmittance of the normal parachute (umbrella top) is 1.

  By using the umbrella cloth 6a that does not easily transmit air to the umbrella edge portion 12, the pressure inside the umbrella body 1 is increased, the internal pressure of the umbrella body 1 is increased, the area on the projection is increased, and the drag is increased. Can be improved. Further, by using the above-described umbrella cloth 6a for the umbrella edge portion 12, the air flow becomes good, the umbrella is quickly opened, the shape of the umbrella edge is easily retained, and the stability is also improved.

  By using an umbrella cloth (an umbrella cloth having an intermediate air permeability) 6c that allows air to permeate as usual at the top 11 of the umbrella, impact at the time of opening can be suppressed, and stability can be improved. Can contribute. By using the umbrella cloth 6b having a large air permeability for the umbrella central portion 13, the drag (air resistance) can be reduced without affecting the impact when opening the umbrella, and the stability of the parachute can be improved. it can.

  It is preferable that the area ratio of the umbrella edge part: umbrella central part: umbrella top part is 50 to 70%: 10 to 40%: 10 to 30%. It is because there exists a possibility that the above-mentioned fall cannot be exhibited if it deviates from these ranges.

  In one embodiment according to the present invention, as shown in FIG. 4, the umbrella body 1 includes an umbrella top portion 11 that forms a hemispherical top portion, an umbrella edge portion 12 that forms an opening surface, and the umbrella edge portion 12 and the umbrella top portion. 11 is provided with a plurality of pockets 14 in the circumferential direction of the umbrella 1 at the position of the umbrella center 13. In this embodiment, the umbrella cloth 6a has a low air permeability at the umbrella edge, the umbrella cloth 6b has a large air permeability at the central part of the umbrella, and the umbrella cloth has an air permeability intermediate between the umbrella cloth 6a and the umbrella cloth 6b at the top of the umbrella. 6c is used. This pocket 14 is open downward (thus opening in the direction of the opening surface of the umbrella), and can receive air drag during descending.

  FIG. 5 is a cross-sectional view of the umbrella. As shown in FIG. 5B, when the parachute swings and tilts, air strongly enters the tilted pocket 14 and the drag force of the air acts strongly (see the arrow), on the other hand. The side pocket 14 'hardly receives air, so the action of air drag is small. For this reason, the umbrella body 1 rotates about the center of gravity G as a rotation axis by the drag force of the air in the pocket 14, and a force for correcting the umbrella body 1 to be vertical acts. For this reason, by providing the pocket 14 in the circumferential direction of the umbrella central portion 13 of the umbrella body 1, a force that suppresses swinging in all directions acts. In order to suppress the swinging by the drag force of air, the position of the pocket 14 is preferably in the vicinity of the circumferential position of the center of gravity G of the hemispherical umbrella 1. 12 is preferably provided in the circumferential direction in the vicinity of 12 (see FIG. 5A).

  The surface distance l between the opening 141 of the pocket 14 and the top of the umbrella 1 at the top of the umbrella 11 is the surface of the umbrella 1 from the top of the top 11 to the end of the umbrella edge 12 (opening surface A). When the distance is L, it is preferably 0.6L to 0.85L. If it deviates from the range of l = 0.6L to 0.85L, it will deviate significantly from the gravity center position G of the umbrella 1, and the action of air drag may be reduced, and the swing of the parachute may not be suppressed well. is there.

  In this embodiment, such a pocket 14 has a structure in which a pocket 14 provided on one of the gores 6 (one gore) and a pocket 14 'extending over two gores are alternately formed. It is not limited to, It may be provided for every 1 gore, and may be provided for every 2 gores. You may make it provide the gore 6 which does not form a pocket in the pocket of said 1 gore and the said 2 gore. That is, one gore pocket may be provided to provide the one gore pocket or the two gore pockets.

  A parachute having the structure shown in FIG. 1 and FIG. In this case, when the air permeability at the top of the umbrella was 1 (normal air permeability), the air permeability at the center of the umbrella was 1.5, and the air permeability at the edge of the umbrella was 0.1. For comparison, the parachute shown in FIG. 4 is manufactured from those having an umbrella cloth of 1.5 (high air permeability), 1.0 (normal air permeability), and 0.1 (low air permeability). Then, the drag force (average resistance coefficient) and swing angle when the parachute was lowered were measured as in the example. The results are shown in FIG.

  According to this, the parachute of the reference example shows an average resistance coefficient similar to that of a parachute manufactured with an umbrella cloth having a small air permeability, and the swing angle is the smallest. That is, it was found that the stability was good.

(Reference example)
The pocket opening comes at a position 70% (l = 0.7 L) from the top of the umbrella top 11 at a distance L (see FIG. 5A) from the top of the umbrella top 11 to the end of the umbrella edge 12. Thus, the parachute as shown in FIG. 4 was manufactured. In other words, the pocket 14 formed over 1 gore and the pocket formed over 2 gore were alternately formed side by side in the circumferential direction of the umbrella central portion 13 (Reference Example 1). Similarly, one gore pocket 14 formed side by side in the circumferential direction of the umbrella central portion 13 at the same position (Reference Example 2), and two pockets 14 formed over the gore formed in the umbrella central portion 13 Manufactured (Reference Example 3).

  As a comparative example, the parachute which provided the slit in each gore 6 was used for the umbrella edge part 12 (it is a skirt part in the said patent) shown by patent 2743171 (comparative example 2). Further, a normal parachute (Comparative Example 1) having no pockets or holes 4 in the circumferential direction of the umbrella 1 as shown in FIG. 6 was prepared.

  The drag (average resistance coefficient) and swing angle when these parachutes were lowered were measured. The results are shown in FIG.

  From the results of FIG. 7, it can be seen that the parachute according to the present invention has an average resistance coefficient equal to or greater than that of Comparative Example 1 which is a normal parachute, and the swing angle is remarkably small. In addition, the parachute of Comparative Example 2 was found to have a greater swing angle than that of Comparative Example 1.

  According to the present invention, by using an umbrella cloth having an intermediate air permeability at the top of the umbrella, the impact at the time of opening the umbrella can be reduced, stability can be improved, and an umbrella having a small air permeability at the edge of the umbrella. By using cloth, it is possible to improve the air flow and improve the stability, increase the pressure in the umbrella, increase the area on the projection and increase the drag Become. Furthermore, by increasing the air permeability of the central portion of the umbrella, stability can be improved without affecting the opening impact.

The side view of one Embodiment of this invention. The top view of the said embodiment. The top view of the gore for comprising the umbrella body of the said embodiment. The side view of the parachute of other embodiment by this invention. Sectional drawing for demonstrating the effect | action of the said embodiment. Explanatory drawing of the said conventional parachute. The figure which shows the average air resistance coefficient and swing angle of the parachute of this invention. The figure which shows the average air resistance coefficient and swing angle of the parachute of a reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Umbrella 11 Umbrella top part 12 Umbrella edge part 13 Umbrella center part 14 Pocket 141 Pocket opening part 2 Suspension thing 3 Suspension rope 4 Hole 5 Hole 6 Gore

Claims (10)

An umbrella body that is substantially hemispherical when extended, the umbrella body includes an umbrella edge portion that forms a hemispherical open surface, an umbrella top portion that forms a top portion of the umbrella body, the umbrella edge portion, and the umbrella top portion A parachute having an umbrella central part to be connected, wherein the umbrella edge has a small air permeability, the umbrella central part has a large air permeability, the umbrella top has the umbrella edge and the umbrella. A parachute characterized by using an umbrella cloth with air permeability in the middle of the center. 2. The parachute according to claim 1, wherein an area ratio of the umbrella edge portion: umbrella central portion: umbrella top portion is 50 to 70%: 10 to 40%: 10 to 30%. The parachute according to claim 1 or 2, wherein when the air permeability of the top of the umbrella is 1, the central part of the umbrella is 1.4 to 1.6 and the edge of the umbrella is 0 to 0.2. The parachute according to any one of claims 1 to 3, wherein a plurality of pockets opened in a circumferential direction are provided in the central portion of the umbrella. The parachute according to claim 4, wherein the pocket is provided in the vicinity of a circumferential position of the center of gravity of the umbrella. The surface distance l of the umbrella body from the opening of the pocket to the top of the umbrella top is 0 when the surface distance of the umbrella body from the top of the umbrella top to the end of the umbrella edge is L. 6. The parachute according to claim 5, wherein the parachute is 6L to 0.85L. The umbrella body is formed by connecting a plurality of substantially triangular gores, and the pocket has one gore pocket formed in a single gore and two gore pockets provided over two gores, The parachute according to any one of claims 4 to 6, wherein one gore pocket and two gore pockets are alternately formed. 7. The parachute according to claim 4, wherein the umbrella body is formed by connecting a plurality of substantially triangular gores, and the pocket is formed by a single gore pocket formed in a single gore. . The parachute according to any one of claims 4 to 6, wherein the umbrella body is formed by connecting a plurality of substantially triangular gores, and the pocket is formed of two gore pockets provided over two gores. The parachute according to any one of claims 4 to 6, 8, and 9, wherein the umbrella body is formed by connecting a plurality of substantially triangular gores, and the pocket is formed by leaving one gore.

Images