Parachute material, parachutes for drones using the same, and drones

Abstract

To provide a parachute material used for a drone parachute, which is light and difficult to affect flight performance and loading performance, which can be stored compact, and which can easily secure a storage space, and easily and visually track a falling drone as visibility is high.SOLUTION: The parachute material used for a drone parachute hood is a fabric made of an aliphatic polyamide yarn having fineness of 15-40 dtex. The fabric is dyed fluorescent color which satisfies a requirement of a fluorescent fabric of JIS T8127(2020) 5.1.1.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a parachute material used for the canopy of a drone parachute, a drone parachute having a canopy made of the parachute material, and a drone. [Background technology]

[0002] In recent years, the industrial use of small, unmanned aerial vehicles (unmanned aircraft) equipped with propulsion and self-control mechanisms, known as drones, has been accelerating.

[0003] However, if a drone experiences unexpected problems such as a malfunction in the propulsion system, an abnormality in the self-control system, communication interruption, or contact with birds or obstacles, the drone itself, the equipment and cargo it carries may be damaged, or a crashed drone may directly hit structures or people on the ground.

[0004] Therefore, a parachute has been proposed to deploy in an emergency to slow down the descent of a falling drone and enable a soft landing (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2019-521038 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Since drones are small flying objects, it is desirable to make the airframe and equipment as light and compact as possible. Thus, drones strive for miniaturization and improvements in payload capacity and volume. For this reason, parachutes, which are auxiliary equipment for drones, also require lighter and more compact designs.

[0007] Furthermore, regarding parachutes for drones, there is a demand to make the parachute canopy more conspicuous, in order to visually track the landing location of a drone that has lost control and made an emergency landing, and to make it easier for people directly below a falling drone to notice and avoid it.

[0008] While various proposals have been made for mechanisms to deploy parachutes in emergencies, the materials used for the parachute canopy have not been sufficiently considered, leaving room for improvement.

[0009] This invention was made to solve these problems, and aims to provide a parachute material for use with drone parachutes that is lightweight, does not significantly affect flight performance or payload capacity, can be stored compactly, making it easy to secure storage space, and has high visibility, making it easy to visually track a falling drone. [Means for solving the problem]

[0010] As a result of diligent research to solve the above problems, the inventors have completed the following embodiment of the present invention.

[0011] (1) The parachute material according to the present invention is a parachute material used for the canopy of a drone parachute, wherein the parachute material is a woven fabric made of aliphatic polyamide yarn with a fineness of 15 to 40 dtex, and the woven fabric is dyed in a fluorescent color that satisfies the requirements for fluorescent fabrics of JIS T8127 (2020) 5.1.1.

[0012] (2) Furthermore, the parachute material according to the present invention has a fabric weight of 20 to 60 g / m 2 It would be good if that were the case.

[0013] (3) Furthermore, the parachute material according to the present invention is preferably dyed with a dye system that includes at least a disperse dye.

[0014] (4) Further, the parachute material according to the present invention preferably has an air permeability of the fabric measured by the JIS L1096 (2010) A method (Fraquil form method) of 1 to 17 cm 3 / cm 2 ·s.

[0015] (5) Further, the parachute material according to the present invention preferably has a water repellent agent adhered to the surface of the aliphatic polyamide yarn.

[0016] The present invention also includes the following.

[0017] (6) The drone parachute according to the present invention is a drone parachute having a canopy made of the parachute material described in (1) to (5) above.

[0018] (7) The drone according to the present invention is a drone having the parachute described in (6) above.

Advantages of the Invention

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described. Note that the embodiments described below are all specific examples of the present invention. Further, the present invention is not limited to only the following aspects, and many modifications are possible within the spirit and scope of the present invention. <00000^8>

[0021] <Parachute Material><0000^01>The parachute material according to this embodiment is a parachute material used for the canopy of a drone parachute, wherein the parachute material is a woven fabric made of aliphatic polyamide yarn with a fineness of 15 to 40 dtex, and the woven fabric is dyed in a fluorescent color that satisfies the requirements for fluorescent fabrics specified in JIS T8127(2020) 5.1.1.

[0022] The parachute material in this embodiment uses aliphatic polyamide yarn. Aliphatic polyamide yarn is a yarn made of aliphatic polyamide. Aliphatic polyamide yarn may be composed solely of aliphatic polyamide, or it may contain aliphatic polyamide and other polymer materials. Aliphatic polyamide yarn only needs to have aliphatic polyamide as its main component material. In this embodiment, the aliphatic polyamide yarn is composed solely of aliphatic polyamide.

[0023] Aliphatic polyamides have excellent mechanical strength while having low density. Furthermore, their high chemical stability means there is little risk of strength reduction due to degradation during storage. For this reason, even if a thin, lightweight, and compact fabric is made using aliphatic polyamide yarn and used as the canopy of a parachute, it can withstand the large expansion pressure that occurs when the parachute deploys. In other words, fabrics made from aliphatic polyamide yarn are suitable for parachute materials.

[0024] Furthermore, because the alkyl chains of aliphatic polyamides are looser and have lower crystallinity compared to aromatic rings, dye molecules can easily penetrate the molecular chains of aliphatic polyamides. For this reason, fabrics made from aliphatic polyamide yarns have the advantage of being easy to dye and having high color development. Examples of fiber materials for aliphatic polyamide yarns include nylon 4, nylon 6, nylon 11, and nylon 12, which are synthesized by ring-opening of lactams or condensation polymerization of amino acids, and nylon 46, nylon 66, and nylon 610, which are synthesized by copolymerization polymerization of dicarboxylic acids and diamines. From the viewpoint of being inexpensive and having excellent mechanical strength, nylon 66 is preferred as the fiber material for aliphatic polyamide yarns. In addition, other fiber materials may be blended, spun, or interwoven as yarns constituting the fabric, as long as it does not contradict the spirit of the present invention.

[0025] The aliphatic polyamide yarn may be a spun yarn, a monofilament yarn, or a multifilament yarn, and may be an untwisted yarn, a twisted yarn, or a processed yarn. The processed yarn is not particularly limited, but examples of processed yarns include false-twist processed yarn, pressed processed yarn, shaped processed yarn, abrasion processed yarn, Taslan processed yarn, interlaced processed yarn, crimped yarn, and side-by-side composite processed yarn.

[0026] The fineness of the aliphatic polyamide yarn in this embodiment is 15 to 40 dtex. A fineness of 15 dtex or higher provides a parachute material strong enough to withstand the large expansion pressures encountered when a parachute deploys. A lower limit of 20 dtex is more preferable for the fineness of the aliphatic polyamide yarn. Furthermore, a fineness of 40 dtex or lower provides a lightweight and compact parachute material. A higher limit of 35 dtex is more preferable for the fineness of the aliphatic polyamide yarn. However, the fineness of the reinforcing yarn in the case of ripstop fabric, as described later, is not limited to these values.

[0027] It is desirable for a water-repellent agent to be applied to the surface of aliphatic polyamide yarn. Because aliphatic polyamide is relatively hygroscopic, if a fabric made of aliphatic polyamide yarn is used as the canopy of a parachute, the parachute canopy will easily absorb moisture. In this case, the moisture absorbed by the parachute canopy may cause condensation or freezing under low temperature conditions such as in cold regions or at high altitudes. The surface tension and freezing of condensed water can cause the parachute canopies to stick together, leading to malfunctions that prevent the parachute from deploying in an emergency.

[0028] In contrast, by using a fabric made of aliphatic polyamide yarn with a water-repellent agent attached to its surface as the parachute canopy, it is possible to suppress the absorption of moisture by the parachute canopy, thereby suppressing condensation and freezing on the parachute canopy. This makes it less likely for the parachute to fail to deploy in an emergency. Any water-repellent agent can be used as the water-repellent agent attached to the surface of the aliphatic polyamide yarn, such as fluorine-based water-repellent agents, paraffin-based water-repellent agents, acrylic-based water-repellent agents, or silicone-based water-repellent agents.

[0029] Furthermore, since it is difficult to perform the fluorescent dyeing process described later on yarn that has a water-repellent agent applied to its surface, it is best to apply the water-repellent treatment to the surface of the yarn after the dyeing process.

[0030] The parachute material according to this embodiment is a woven fabric. The weave of the fabric can be any form, such as plain weave, twill weave, satin weave, or modified weave. From the viewpoint of high mechanical strength and dimensional stability, and the fact that it is less likely to burst or change in breathability even when subjected to the large expansion pressure during deployment, the material of the parachute is preferably a plain weave.

[0031] Furthermore, to improve the mechanical strength of the parachute material, such as resistance to bursting and tearing, a ripstop fabric may be used in which threads with higher mechanical strength than the surrounding threads, such as tightly twisted threads, threads with higher fineness, or threads made of materials stronger than aliphatic polyamide threads, are woven in a grid pattern at intervals of several millimeters.

[0032] The basis weight of the fabric used as the parachute material according to this embodiment is preferably 20 to 60 g / m 2 . When the basis weight of the fabric is 20 g / m 2 or more, it is easy to obtain the strength to withstand the large expansion pressure when the parachute is deployed and the high airtightness (low air permeability) for decelerating the falling drone. The lower limit value of the basis weight of the fabric is more preferably 25 g / m 2 . Further, when the basis weight of the fabric is 60 g / m 2 or less, a lightweight and compact parachute material can be obtained, and it is easy to obtain the appropriate air permeability described later. The upper limit value of the basis weight of the fabric is more preferably 50 g / m 2 .

[0033] In addition, the air permeability of the fabric used as the parachute material according to this embodiment is preferably 1 to 17 cm 3 / cm 2 ·s. When the air permeability of the fabric is 1 cm 3 / cm 2 ·s or more, when the parachute is deployed, air can escape from the canopy appropriately, and it becomes easier to suppress the impact on the drone body and the payload due to the rapid deceleration at the time of parachute deployment. The lower limit value of the air permeability of the fabric is more preferably 7 cm 3 / cm 2 ·s. Further, when the air permeability of the fabric is 17 cm 3 / cm 2 ·s or less, it is easy to obtain the high airtightness for decelerating the falling drone. The upper limit value of the air permeability of the fabric is more preferably 13 cm 3 / cm 2 ·s. The air permeability of the fabric can be measured by the JIS L1096 (2010) A method (Fraquil method).

[0034] Means for adjusting the breathability of the fabric include fabric design such as yarn fineness and weave density, adjustment of weave density by tenter processing, calendering, resin coating, and perforation such as needle punching. Since calendering, resin coating, and perforation reduce the tear strength of the fabric, it is preferable to adjust the breathability of the fabric by fabric design or tenter processing.

[0035] The parachute material according to this embodiment is dyed in a fluorescent color that satisfies the requirements for fluorescent fabrics in JIS T8127(2020) 5.1.1 (same as the requirements for fluorescent materials in ISO 20471(2013) 5.1.1). Because the fabric used for the parachute is dyed in a fluorescent color that satisfies the aforementioned requirements, the deployed parachute becomes easily visible with high contrast against the blue sky, especially on sunny days with very high illumination.

[0036] Any coloring agent can be used to dye textiles, such as disperse dyes, acid dyes, cationic dyes, direct dyes, reactive dyes, vat dyes, sulfur dyes, and pigments, as long as it can produce a fluorescent color that satisfies the required characteristics.

[0037] Generally, fibers made of aliphatic polyamides are often dyed with acid dyes, which offer high fastness against washing, friction, and light, and are less prone to migration sublimation. Therefore, there is a tendency to avoid dyeing aliphatic polyamide fibers with disperse dyes, which have low fastness and are prone to migration sublimation. However, for parachute materials that are stored for long periods in isolation from the outside world within the parachute's storage compartment, fastness and migration sublimation are not particularly problematic. From the perspective of obtaining a parachute material with high brightness and higher visibility, it is preferable to dye woven fabrics made of aliphatic polyamide yarn, which will be used as parachute material, with disperse dyes rather than general acid dyes. In this case, it is preferable that the woven fabric be dyed with a dye system that includes at least a disperse dye. A dye system that includes at least a disperse dye refers to a system in which a disperse dye alone, a mixture of a disperse dye and other dyes, and a mixture of dyeing aids such as dispersants, leveling agents, and acids as needed. From the perspective of achieving higher brightness, it is particularly preferable that the dye system contains only a disperse dye.

[0038] The method of dyeing the fabric is not particularly limited. For example, the coloring agent may be kneaded into the aliphatic polyamide yarn during spinning, or the yarn may be dyed at the spinning stage to prepare aliphatic polyamide yarn dyed in a fluorescent color, and the fabric may be woven using the dyed aliphatic polyamide yarn. Alternatively, a colorless fabric made of aliphatic polyamide yarn may be dyed in a fluorescent color. If water-repellent treatment is also applied to the parachute material, it is preferable to perform the dyeing process before the water-repellent treatment so that the dyeing process is not hindered by the water-repellent agent.

[0039] <Parachute for drones> The drone parachute according to this embodiment is a drone parachute having a canopy made of the aforementioned parachute material. A drone parachute using the aforementioned parachute material for the canopy is lightweight, does not significantly affect flight performance or payload capacity, can be stored compactly, making it easy to secure storage space, and has high visibility, making it easy to visually track a falling drone.

[0040] The parachute for the drone according to this embodiment may be a mushroom-shaped type or a ram-air type with a wing-like shape. From the viewpoint of the parachute's canopy being less likely to collapse and being able to deploy stably, the parachute for the drone according to this embodiment is preferably mushroom-shaped.

[0041] Furthermore, even if the ends of the parachute material are directly connected to the drone body, the parachute material forming the canopy may be connected to the drone body via a suspension line. From the viewpoint of making it easier to stabilize the attitude of the drone body when the parachute is deployed, the configuration in which the canopy and the drone body are connected via a suspension line is preferred.

[0042] The parachute canopy using parachute material according to this embodiment can be designed in an appropriate form depending on the mass of the drone body to which it is connected, the maximum altitude it can reach, and so on. For example, the parachute canopy may consist of a single sheet of parachute material, multiple sheets of parachute material may be stacked together, or it may have a form having multiple cells partitioned by ribs.

[0043] <Drone> The drone according to this embodiment is a drone equipped with a drone parachute. The drone equipped with the drone parachute has a lightweight parachute material that can be stored compactly, and even when the drone parachute is loaded, its flight performance and payload capacity are not significantly affected, it is easy to secure storage space, and it is easy to visually track the drone while it is falling.

[0044] (Examples) The parachute material for drones according to this embodiment will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Any modifications made without departing from the objective of the present invention are all included within the technical scope of the present invention. Furthermore, the various performance measurements, tests, and evaluations in the following examples were performed by the following methods.

[0045] <Inspector> The basis weight of the parachute material was determined using the mass of a test piece cut into a 1-meter square.

[0046] <Storage volume> The compactness (storage volume) of the parachute material when stored was evaluated using the following method: A 1m square test piece was rolled by hand and packed into a transparent acrylic pipe with an inner diameter of 96mm and a height of 50cm. The pipe was then stood upright, and a lid with an outer diameter of 94mm and a weight (totaling 1kg) were dropped into the pipe. The distance from the ground to the bottom edge of the lid was measured, and this value was used as the height to determine the volume of the cylindrically stored test piece, which was then used as the storage volume.

[0047] <Breathability> The breathability of the parachute material was measured according to Method A (Fragile method) specified in JIS L1096 (2010).

[0048] <Tensile strength> The tensile strength of the parachute material was measured according to Method A (strip method) specified in JIS L1096 (2010). Measurements were taken for both the warp and weft under constant-speed elongation conditions: a specimen width of 50 mm, a gripping distance of 200 mm, and a tensile speed of 200 mm / min.

[0049] <Water repellency> The water repellency of the parachute material was measured in accordance with the water repellency test (spray test) specified in JIS L1092 (2009).

[0050] <Chromatic coordinates and luminance ratio> The chromaticity coordinates and luminance ratios of the parachute material were measured using a spectrophotometer (CM-2600C (manufactured by Konica Minolta, Inc.)) in accordance with the measurement method specified in JIS T8127(2020) 5.1.1 Requirements for fluorescent fabrics. The chromaticity coordinates (x and y) and luminance ratio β (=Y / 100) were measured in the CIE 1931 XYZ color space. Furthermore, conformity was determined by comparing the results with the range of chromaticity coordinates and the lower limit of luminance ratios for fluorescent yellow and fluorescent orange-red specified in JIS T8127(2020) 5.1.1 Requirements for fluorescent fabrics.

[0051] <Visibility> On a sunny day around noon, a 1-meter square test specimen in a frame was placed on the roof of a building, and subjects were asked to stand on the roof of another building approximately 400 meters away to test whether they could quickly find the test specimen. A "○" was given if they found the test specimen quickly, and a "×" was given if it took them a long time to find it.

[0052] (Example 1) A fabric was prepared using nylon 66 yarn with a fineness of 33 dtex (weave density: warp 123 threads / 2.54 cm x weft 90 threads / 2.54 cm).

[0053] The aforementioned fabric was dyed using Twintex Brill. Flavin GN200 (manufactured by Futaba Sangyo Co., Ltd., a fluorescent disperse dye) at 105°C for 30 minutes, then washed with water and dried at 120°C for 30 seconds to obtain a parachute material dyed fluorescent yellow. The evaluation results of the obtained parachute material are shown in Table 1.

[0054] (Comparative Example 1) A parachute material dyed fluorescent yellow was obtained in the same manner as in Example 1, except that a plain weave fabric made of nylon 66 yarn with a fineness of 44 dtex (weave density: 128 warp threads / 2.54 cm × 92 weft threads / 2.54 cm) was used. The evaluation results of the obtained parachute material are shown in Table 1.

[0055] (Comparative Example 2) A parachute material dyed fluorescent yellow was obtained in the same manner as in Example 1, except that a plain weave fabric made of nylon 66 yarn with a fineness of 11 dtex (weave density: 120 warp threads / 2.54 cm × 102 weft threads / 2.54 cm) was used. The evaluation results of the obtained parachute material are shown in Table 1.

[0056] (Comparative Example 3) A plain weave fabric made from polyethylene terephthalate (PET) yarn with a fineness of 33 dtex (weave density: warp 110 threads / 2.54 cm × weft 90 threads / 2.54 cm) was prepared.

[0057] The aforementioned fabric was dyed using Twintex Brill. Flavin GN200 (manufactured by Futaba Sangyo Co., Ltd., a fluorescent disperse dye) at 135°C for 30 minutes, then washed with water and dried at 120°C for 30 seconds to obtain a parachute material dyed fluorescent yellow. The evaluation results of the obtained parachute material are shown in Table 1.

[0058] (Comparative Example 4) The fabric used in Example 1 was used as parachute material without any dyeing. The evaluation results are shown in Table 1.

[0059] (Example 2) The fabric used in Example 1 was dyed at 105°C for 30 minutes using Twintex Brill. Flavin GN200 (Futaba Sangyo Co., Ltd., fluorescent disperse dye) and Kayacyl Rhodamine FB (Nippon Kayaku Co., Ltd., fluorescent acid dye) as dyes, then washed with water and dried at 120°C for 30 seconds to obtain a parachute material dyed fluorescent orange-red. The evaluation results of the obtained parachute material are shown in Table 1.

[0060] (Example 3) A parachute material dyed fluorescent yellow was obtained in the same manner as in Example 1, except that a fabric made of nylon 66 yarn with a fineness of 22 dtex (weave density: 163 warp threads / 2.54 cm × 147 weft threads / 2.54 cm) was used. The evaluation results of the obtained parachute material are shown in Table 1.

[0061] (Example 4) A parachute material dyed fluorescent yellow was obtained in the same manner as in Example 1, except that a fabric made of nylon 66 yarn with a fineness of 22 dtex (weave density: warp 206 threads / 2.54 cm × weft 163 threads / 2.54 cm) was used. The evaluation results of the obtained parachute material are shown in Table 1.

[0062] (Example 5) The parachute material obtained in Example 4 was immersed in a 3% by mass aqueous dispersion of Asahi Guard AG-E081 (manufactured by AGC Inc., a fluorine-based water repellent), squeezed using a mangle roll, and then dried at 170°C for 1 minute to obtain a fluorescent yellow dyed parachute material in which the water repellent was attached to the surface of the nylon 66 yarn. The evaluation results of the obtained parachute material are shown in Table 1.

[0063] [Table 1]

[0064] Table 1 shows the following: Parachute material made from aliphatic polyamide yarn with a fineness of 15-40 dtex and dyed in a fluorescent color that meets the requirements for fluorescent fabrics in JIS T8127(2020) 5.1.1 is lightweight, can be compactly stored, and has high visibility.

Claims

1. A parachute material used for the canopy of a drone parachute, wherein the parachute material is a woven fabric made of aliphatic polyamide yarn with a fineness of 15 to 40 dtex, the woven fabric is dyed in a fluorescent color that satisfies the requirements for fluorescent fabrics of JIS T8127 (2020) 5.1.1, and the woven fabric is dyed with a dye system that includes at least a disperse dye.

2. The weight of the aforementioned fabric is 20-60 g / m ２ The parachute material according to claim 1.

3. The air permeability of the aforementioned fabric, as measured by JIS L1096 (2010) Method A (Fragile method), is 1 to 17 cm. ３ / cm ２ The parachute material according to claim 1, wherein the material is s.

4. The parachute material according to claim 1, wherein a water-repellent agent is attached to the surface of the aliphatic polyamide yarn.

5. A parachute for a drone having a canopy made of the parachute material described in any one of claims 1 to 4.

6. A drone having a parachute for a drone as described in claim 5.

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