JP7577508B2 - Safety device and flying object equipped with the safety device - Google Patents

Description

The present invention relates to an actuator, a safety device equipped with the actuator and configured to launch a projectile such as a parachute or paraglider, and an aircraft equipped with the safety device.

In recent years, with the development of autonomous control technology and flight control technology, the industrial use of flying objects equipped with multiple rotors, for example drones, is accelerating. Drones fly, for example, by rotating multiple rotors simultaneously in a balanced manner, and ascend and descend by increasing and decreasing the rotation speed of the rotors, and move forward and backward by tilting the aircraft through increasing and decreasing the rotation speed of the rotors. Such flying objects are expected to expand worldwide in the future.

However, the risk of aircraft falling accidents such as those described above is seen as a danger, and is preventing the widespread use of aircraft. In order to reduce the risk of such accidents, parachute devices for aircraft are being commercialized as safety devices.

For example, as an example of the above-mentioned parachute safety device, the applicant has filed an application relating to the following Patent Document 1. As shown in FIG. 1 of the following Patent Document 1, the safety device of this Patent Document 1 comprises a piston member (sliding member), a cylinder that houses the piston member and has a hole through which the piston member protrudes outward when actuated, a push-up member that is pushed up in one direction by the piston member, a projectile that is supported and pushed up by the push-up member, and a gas generator that moves the piston member within the cylinder, and the push-up member has a support portion that is located on the distal end side of the piston member based on the tip of the piston member in the movement direction of the piston member. In addition, the bottom of the push-up member is fixed to the tip of the piston member.

JP 2020-1680 A

In the case of a safety device such as that in Patent Document 1, it is necessary to consider the strength against impacts when the actuator is operated, so it is necessary to use relatively strong parts. However, relatively strong parts need to be thicker and tend to be heavy, so the weight of a safety device such as that in Patent Document 1 tends to be relatively large. In the case of such a safety device, there are cases where the weight has an impact when it is attached to an aircraft (for example, energy consumption becomes faster and continuous flight time is shortened).

The present invention aims to provide an actuator that can be made lighter than conventional actuators while mitigating the impact caused by actuation, a safety device equipped with the actuator and capable of projectiles such as a parachute or paraglider, and an aircraft equipped with the safety device.

(1) A safety device according to the present invention is an actuator used in a safety device for an aircraft, comprising: a sliding member having a main body and a rod-shaped portion connected to the main body and narrower than the main body; a tubular member provided around a part of the rod-shaped portion with one end of the tubular member in contact with the main body; a cylinder that slidably accommodates the sliding member and the tubular member therein; a stopper member provided at one end of the cylinder, having a hole that causes the sliding member to protrude outward from the inside when actuated, and restricting the movement of the tubular member within the cylinder when actuated; and a stopper member provided at the other end of the cylinder that restricts the sliding member from moving. the tubular member being made of a material that undergoes plastic deformation and has a tensile strength lower than that of the sliding member and the stopper member; a push-up member having a bottomed tubular portion arranged to cover at least a portion of the cylinder, and a flange-shaped portion formed to protrude outward from an opening of the bottomed tubular portion or a midway portion of a side surface, and pushed up in one direction by the sliding member; and an ejection object that is pushed up while being supported by the flange-shaped portion of the push-up member.

(2) In the safety device of (1) above, it is preferable that, during operation, when the tubular member collides with the stopper member and is plastically deformed, the tubular member and the inner wall portion of the cylinder are separated by a predetermined distance or more so that the tubular member does not come into contact with the inner wall portion of the cylinder.

(3) In the safety device of (1) or (2) above, it is preferable that a tapered portion is formed inside the opening of the tubular member on the side that collides with the stopper member.

(4) From another viewpoint, a safety device of the present invention includes a sliding member having a main body, a rod-shaped portion that is integrated with the main body and has a width smaller than that of the main body, and at least one protrusion that is fixed to a periphery of a part of the rod-shaped portion; a cylinder that slidably houses the sliding member therein; a stopper member that is provided at one end of the cylinder, has a hole through which the sliding member protrudes outward from the inside when actuated, and with which the protrusion collides when actuated; and a power source that is provided at the other end of the cylinder and generates power to slide the sliding member. the protrusion has an actuator fixed to the rod-shaped portion with such a strength that when it collides with the stopper member during operation, the part where the protrusion is fixed to the rod-shaped portion is shear-broken; a bottomed tubular portion arranged to cover at least a part of the cylinder; and a flange-shaped portion formed to protrude outward from an opening of the bottomed tubular portion or a midway part of a side surface, the protrusion may comprise: a push-up member that is pushed up in one direction by the sliding member; and an ejection object that is supported and pushed up by the flange-shaped portion of the push-up member.

(5) In the safety devices of (1) to (4) above, it is preferable that a ring-shaped seal member that abuts against at least a part of the sliding member is provided on a part of the inner wall surface of the hole, and at least a portion of the outer surface of the sliding member that comes into contact with and rubs against the seal member when the sliding member is assembled is formed into a smooth shape.

( 6 ) The flying object according to the present invention is characterized in that it is equipped with any one of the safety devices (1) to (5) above , and the projectile is a parachute or a paraglider .

The present invention provides an actuator that can be made lighter than conventional actuators while mitigating the impact caused by actuation, a safety device that includes the actuator and launches a projectile such as a parachute or paraglider, and an aircraft that includes the safety device.

1 is a cross-sectional view showing a safety device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an actuator in the safety device of FIG. 1 . 3 is a partial enlarged view of a tip portion of a piston member in the actuator of FIG. 2. 1A is a cross-sectional view of a tubular member in the actuator of FIG. 2 before the safety device of FIG. 1 is activated, and FIG. 1B is a cross-sectional view of a tubular member in the actuator of FIG. 2 after the safety device of FIG. 1 is activated. FIG. 2 is a diagram showing an aircraft to which the safety device of FIG. 1 is applied. FIG. 3 is a diagram showing a modification of the actuator of FIG. 2 .

Below, a safety device equipped with an actuator according to an embodiment of the present invention will be described with reference to Figures 1 to 5.

As shown in FIG. 1, the safety device 100 includes an actuator 1, a push-up member 15 that is pushed up in one direction (upward in FIG. 1) by the actuator 1, a projectile 16 that is supported and pushed up by the push-up member 15, a bottomed cylindrical container 18 that contains the actuator 1, the push-up member 15, and the projectile 16, and a lid 21 that closes the open end of the container 18. In this embodiment, the projectile 16 is a parachute or a paraglider.

The actuator 1 comprises a piston member 10 which is a sliding member, a cylinder 14 which houses the piston member 10 and has a hole 13 through which the piston member 10 protrudes outward (upward in Figs. 1 and 2) when actuated, a base 2 (squib holder) to which one end of the cylinder 14 is crimped and which is attached to the center of the bottom inside the container 18, and a gas generator (such as a micro gas generator) 17 which serves as a power source for moving the piston member 10 inside the cylinder 14.

The piston member 10 has a main body 10a with an outer diameter approximately equal to the inner diameter of the cylinder 14, a rod-shaped portion 10b connected to the main body 10a, extending upward and having a smaller diameter than the main body 10a, a hole 10c provided inside the main body 10a and the rod-shaped portion 10b, a female threaded portion 10d provided at the upper end of the rod-shaped portion 10b, a groove portion 10e provided in the circumferential direction of the main body 10a, a reduced diameter portion 10f with a smaller diameter than the rod-shaped portion 10b, and a tapered portion 10g formed between the rod-shaped portion 10b and the reduced diameter portion 10f.

At least the upper end side of the rod-shaped portion 10b is formed in a non-circular cross section, although this is not shown. Here, a non-circular shape refers to, for example, a polygonal shape, an elliptical shape, a star shape, or a gear shape, but any shape is included as long as it is non-circular. In addition, the tubular member 4 is fitted or loosely fitted in the lower part of the rod-shaped portion 10b with one end in contact with the main body portion 10a. There may be a gap between the inner wall of the tubular member 4 and the outer wall of the rod-shaped portion 10b, but the gap should be within a range that does not prevent plastic deformation due to approximately uniform compression during a collision, as described below.

2, the tubular member 4 is held by the holding member 5 at the lower part of the rod-shaped part 10b with one end in contact with the main body part 10a. The tubular member 4 is made of a material that undergoes plastic deformation and has a lower tensile strength than the piston member 10 and the stopper member 23 described below (e.g., metals such as iron, aluminum, brass, copper, alloys such as stainless steel, resins, etc.). Here, the holding member 5 may be an elastic member such as rubber, or may be made of the same material as the tubular member 4, and may be in the form of a ring or a clip.

As shown in FIG. 4(a), tapered portions 4a and 4b are formed on the inside of both openings of the tubular member 4. In addition, the tubular member 4 and the inner wall of the cylinder 14 are separated by a predetermined distance (for example, a distance at which the tubular member 4, which is plastically deformed by approximately uniform compression when colliding with the stopper member 23, does not come into contact with the inner wall of the cylinder 14) so that the tubular member 4 does not come into contact with the inner wall of the cylinder 14) or more. As a result, even if the tubular member 4 collides with the stopper member 23 and is plastically deformed, it deforms without being hindered by the inner wall of the cylinder 14, and the impact of the piston member 10 is sufficiently mitigated.

The hole 10c is formed along the central axis from the lower end of the main body 10a to the middle of the rod-shaped portion 10b. This makes the piston member 10 lighter than if the hole 10c was not formed.

The female threaded portion 10d is formed from the tip of the rod-shaped portion 10b to partway along the central axis. The male threaded portion 50b of the bolt member 50, which will be described later, can be screwed into the female threaded portion 10d.

A sealing member 11 such as an O-ring is provided in the circumferential direction in the groove portion 10e.

As shown in FIG. 3, the tapered portion 10g is formed to have a smooth shape (e.g., a rounded shape without corners) between the rod-shaped portion 10b and the reduced diameter portion 10f. This makes it possible to prevent the sealing member 12, such as an O-ring, from getting caught, which can prevent the sealing member 12 from being damaged and its performance from being reduced. It also helps to prevent injuries during device assembly.

A roughly cylindrical stopper member 23 is provided at the top of the cylinder 14, and is arranged to surround a part of the rod-shaped portion 10b of the piston member 10. That is, the rod-shaped portion 10b is arranged in a state of being inserted through the hole portion 13 of the stopper member 23. The cylinder 14 is also provided with a through hole 14a for releasing air in the space 6 to the outside during operation. Note that although only one through hole 14a is provided in Figs. 1 and 2, multiple through holes 14a may be provided in the circumferential direction.

The stopper member 23 restricts the movement of the tubular member 4 within the cylinder 14, and has a groove 23a provided along the outer periphery and a groove 23b provided along the inner periphery. The groove 23a is used to crimp and fix the other end of the cylinder 14 to the stopper member 23. In addition, a seal member 12 such as an O-ring is provided in the circumferential direction in the groove 23b.

The material of the cylinder 14 may be selected and the thickness of the outer periphery may be appropriately adjusted so that the cylinder 14 can undergo radial plastic deformation when the piston member 10 of the actuator 1 becomes immobile for some reason, and when the initial combustion volume of the actuator 1 is reduced and the explosive burns, generating a combustion pressure greater than the pressure resistance value of the cylinder 14 (in an abnormal situation). Examples of materials that constitute the cylinder 14 include metals such as iron, aluminum, brass, and copper, and alloys such as stainless steel. As a result, in the above-mentioned abnormal situation, the cylinder 14 undergoes radial plastic deformation, and the sealing performance of the sealing member 12 such as an O-ring is reduced (relaxed), and a gap through which the generated gas can pass is formed between the sealing member 12 and the inner wall of the cylinder 14. Therefore, by allowing the gas generated during the abnormal situation to leak out from this gap, the gas is released from the through hole 14a to the outside of the cylinder 14, and then passes through the gap between the outer wall of the cylinder 14 and the inner wall of the bottomed cylindrical portion 19, passes through the inside of the container 18, and is released from the vent holes 24 and 25 to the outside of the container 18, so that the cylinder 14 does not break (fail-safe function). Note that when this fail-safe function is provided, a space (gap) is provided between the outer wall of the cylinder 14 and the inner wall of the bottomed cylindrical portion 19 so that the cylinder 14 can be sufficiently plastically deformed in the radial direction.

The gas generator 17 is press-fitted into the lower open end of the cylinder 14 and is positioned below the main body 10a (described below) of the piston member 10. A cylindrical member 3 is provided around the cup body 17a of the gas generator 17 to form a predetermined distance between the gas generator 17 and the piston member 10.

The push-up member 15 is made of metal (aluminum, iron, or the like, and may be an alloy), resin, or a composite material of resin and metal, CFRP, fiber-reinforced resin, or the like, and as shown in FIG. 1, has a bottomed tubular portion 19 arranged to cover a part of the cylinder 14, that is, the outer part of the cylinder 14 except for the vicinity of the open end on the side where the gas generator 17 is arranged, and a disk-shaped support portion 20 provided as a flange (brim-shaped portion) at the opening of the bottomed tubular portion 19 and supporting the projectile 16.

The bottomed tubular portion 19 has a bottom 19a having a substantially flat or columnar shape (substantially columnar in this embodiment), a hole 51 formed on the lid portion 21 side of the bottom 19a, a hole 52 (second hole) having a smaller diameter than the hole 51, and a hole 53 (first hole) communicating with the hole 51 via the hole 52 and having a larger diameter than the hole 52. The hole 51 has a diameter larger than the diameter of the head portion 50a of the bolt member 50. The hole 52 has a diameter smaller than the diameter of the head portion 50a, and can guide the male thread portion 50b of the bolt member 50 inserted from the hole 51 side to the hole 53 side. The hole 53 has a shape that is approximately the same as one end (upper end) of the rod-shaped portion 10b, and serves as a fitting portion into which one end of the rod-shaped portion 10b fits by inserting one end of the rod-shaped portion 10b through an insertion opening 53a provided on the cylinder 14 side of the bottom 19a of the bottomed tubular portion 19.

The bolt member 50 connects the rod-shaped portion 10b and the push-up member 15 by inserting the male threaded portion 50b into the hole portion 52 from the hole portion 51 side and screwing it into the female threaded portion 10d of the rod-shaped portion 10b fitted into the hole portion 53. At this time, one end of the rod-shaped portion 10b is non-circular and fits into the hole portion 53 of approximately the same shape, so that the rod-shaped portion 10b does not rotate together when the bolt member 50 is screwed into the female threaded portion 12a. Specifically, since the tip portions of the push-up member 15 and the piston member 10 are non-circular and fit together, when the bolt member 50 is fastened, the push-up member 15 can be rotated while being fixed, and the piston member 10 tightens toward the gas generator 17, and can be tightened without rotating together.

In the initial state, the support part 20 is provided spaced apart from the inner bottom surface of the container 18. The support part 20 also has an air vent 26 for reducing the effect of negative pressure generated between the bottom of the projectile 16 and the support part 20 during operation, making it easier for the projectile 16 to be projected. The outer periphery of the support part 20 is formed so as not to come into contact with the inside of the container 18. The upper surface of the support part 20 is also provided with at least one movement prevention member 27 (eight in this embodiment) for preventing the projectile 16 from moving in the circumferential direction of the bottomed tubular part 19.

The movement prevention members 27 are generally triangular members made of resin or a composite material of resin and metal, CFRP, fiber-reinforced resin, etc., and are provided in multiple rotational symmetry around the bottomed tubular portion 19. In addition, a through hole 26 is provided between each of the movement prevention members 27.

As shown in FIG. 1, the bottom of the container 18 is provided with a number of ventilation holes 24 that connect the inside of the container 18 to the outside. In addition, the side wall of the container 18 is provided with a number of ventilation holes 25 that connect the inside of the container 18 to the outside. When the push-up member 15 moves rapidly inside the container 18, negative pressure is generated in the area between the push-up member 15 and the bottom surface of the container 18. This makes it difficult to move the push-up member 15. Therefore, by providing the above ventilation holes 24, 25, the negative pressure phenomenon can be reduced, and the push-up member 15 can be moved smoothly.

The projectile 16 is contained within the container 18 between the inner surface of the container 18 and the outer surface of the bottomed tubular portion 19 of the push-up member 15, for example, so as to surround the outer surface of the bottomed tubular portion 19. The projectile 16 is also folded so that its outside does not come into contact with the inside of the container 18. The projectile 16 is connected to one end of a string (not shown), for example, and the other end of the string is connected to the inside of the container 18 or to the body 31 of the flying object 30, which will be described later.

The gas generator 17 may be an igniter alone, or a gas generator equipped with an igniter and a gas generating agent. A hybrid or stored type gas generator may also be used, in which a gunpowder-type igniter is used to break the seal of a small gas cylinder and release the gas inside to the outside. In this case, the pressurized gas in the gas cylinder may be a non-flammable gas such as argon, helium, nitrogen, or carbon dioxide, or a mixture of these. In addition, the gas generator may be equipped with a heating element made of a gas generating agent composition or a thermite composition, etc., in order to reliably propel the piston when the pressurized gas is released.

The piston member 10, cylinder 14, push-up member 15, gas generator 17, etc. mainly constitute the ejection section that ejects the ejection object 16.

In the above configuration, when the gas generator 17 is activated when, for example, an aircraft on which the safety device 100 is mounted falls, the pressure of the gas generated by the activation propels the piston member 10 upward in the cylinder 14. As a result, the push-up member 15 having the bottomed cylindrical portion 19 connected to the rod-shaped portion 10b of the piston member 10 is propelled (protruded) upward in the container 18. As a result, the lid portion 21 is removed, the open end of the container 18 is opened, and the projectile 16 is ejected from the container 18 to the outside (upward in the paper of FIG. 1). At this time, the piston member 10 and the tubular member 4 move upward, but the tubular member 4 collides with the stopper member 23, and due to approximately uniform compression, the diameter of the tubular member 4 is expanded from the initial state shown in FIG. 4(a) so as to open from the upper opening side, and the tubular member 4 is plastically deformed to the shape shown in FIG. 4(b). This mitigates the impact of the operation of the piston member 10 on the entire safety device 100. In particular, it reduces the impact on the push-up member 15 connected to the piston member 10. And, if the projectile 16 is a parachute or a paraglider, the projectile 16 is deployed after being ejected from the container 18.

The safety device 100 is connected and fixed to the body 31 of the flying object 30 via a connecting member 40, as shown in FIG. 5. At this time, as shown in FIG. 5, the connecting member 40 connects the container 18 to the body 31 in a position that does not block the air vent 24. Therefore, the flying object 30 includes the body 31, the safety device 100 connected to the body 31, one or more propulsion mechanisms (e.g., propellers, etc.) 32 connected to the body 31 and propelling the body 31, and a plurality of legs 33 provided on the lower part of the body 31. Here, in reality, a socket for passing electricity is fitted to the electrode at the bottom of the gas generator 17, but for convenience of explanation, this is omitted in FIG. 1 and FIG. 5.

As described above, according to this embodiment, it is possible to provide a safety device 100 equipped with an actuator 1 that can reduce the weight of the actuator 1 compared to conventional devices while mitigating the impact of actuation. In particular, since it is possible to mitigate the impact on the push-up member 15 in the actuator 1, the necessary strength can be maintained even if the thickness of the push-up member 15 is reduced to a certain extent (for example, made of resin and 2 mm thick) to reduce the weight. Therefore, there is no need to use a relatively high-strength material for the push-up member 15, which is advantageous in terms of cost.

In addition, tapered portions 4a, 4b are formed on the inside of both openings of the tubular member 4. Also, the tubular member 4 is spaced a distance away from the inner wall of the cylinder 14 so that the tubular member 4 does not come into contact with the inner wall of the cylinder 14 after being plastically deformed when colliding with the stopper member 23. As a result, even if the tubular member 4 collides with the stopper member 23 and is plastically deformed, it can deform without being hindered by the inner wall of the cylinder 14, and the impact of the piston member 10 can be sufficiently mitigated.

In addition, an aircraft 30 equipped with a safety device 100 configured as described above can be obtained.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims.

For example, the present invention includes the following modified examples. In the above embodiment, the support portion 20 of the push-up member 15 extends from the edge of the opening of the push-up member 15, but this is not limited to the above. Depending on the design, such as to match the size of the projectile 16, the support portion 20 may extend from the middle of the bottomed tubular portion 19 of the push-up member 15.

In addition, in the above embodiment, a gas generator is used as the power source, but the configuration is not limited as long as it is possible to impart a driving force to the sliding member to propel the sliding member inside the cylinder, and for example, an elastic body such as a spring may be used.

In addition, in the above embodiment, the container 18 is formed in a cylindrical shape, but this is not limited to this and may be formed in other shapes, such as a rectangular tube.

In addition, in each of the above embodiments, when a parachute or paraglider is used as the projectile, the parachute or paraglider may be packed. The packing is configured to break or peel off when activated.

In addition, in each of the above embodiments, a parachute or a paraglider is mentioned as the projectile, but the present invention is not limited to this, and an object including a lift generating member may be projected as the projectile. Examples of the lift generating member include a parafoil, a Rogallo type parachute, a single surface type parachute, an airplane wing, a propeller, and a balloon. In addition, when the lift generating member has a control line, it is desirable for the safety device to have a steering mechanism that can change the inclination angle of the projected lift generating member using the control line. This steering mechanism, for example, has multiple reels that respectively wind up multiple control lines connected to the lift generating member, and a motor that powers these reels, and the lift generating member can be pulled or released as appropriate by driving the motor to wind up or unwind the control line.

In addition, in the above embodiment, it is preferable that the cylinder, power source, and container are fixed to the aircraft body by means such as rubber bands, belts, strings, or other means (mechanical joints, bolts, fasteners, adhesives, etc.).

In addition, instead of the actuator 1 of the above embodiment, an actuator 101 of a modified example shown in FIG. 6 may be used. The actuator 101 of this modified example will be specifically described below. Note that unless otherwise specified, parts similar to those of the above embodiment are designated by reference numerals with the same last two digits, and descriptions may be omitted. Furthermore, in this modified example, unless otherwise specified, the same parts as those of the above embodiment are used.

The actuator 101 of this modified example differs from the actuator 1 in that a piston member 110 is used instead of the piston member 10. Specifically, the actuator 101 differs from the actuator 1 in that the actuator 101 does not use the tubular member 4 and the holding member 5, but instead has at least one flange-shaped portion (two protrusions 110h, 110i in FIG. 6) fixed around a part of the rod-shaped portion 110b.

When the protrusions 110h and 110i collide with the stopper member 123 during operation, the portions where the protrusions 110h and 110i are fixed to the rod-shaped portion 110b (the connection portions between the protrusions 110h and 110i and the rod-shaped portion 110b) are fixed to the rod-shaped portion 110b with a strength that causes shear failure. The shape of the protrusions 110h and 110i may be flange-shaped or may have multiple rod-shaped portions protruding in the radial direction. The fixing method in this case may be integral molding by machining (cutting), or attachment by welding, etc.

According to the actuator 101 configured as described above, when the portion of the protrusions 110h, 110i fixed to the rod-shaped portion 110b is shear-broken, the impact of the collision between the protrusions 110h, 110i (piston member 110) and the stopper member 123 can be mitigated, thereby achieving the same effect as the actuator 1.

Example 1
A push-up member was designed, which was assumed to be made of resin (here, glass fiber reinforced PA (polyamide) 66 (PA66 + GF33%) containing 33% GF (glass fiber) and having a Young's modulus of 10 GPa) for a safety device having the same configuration as the above embodiment, and a simulation experiment was carried out to investigate how the deflection of the support part (flange) of the push-up member changes depending on the thickness of the push-up member. The experimental method is shown below.

The deflection of the support part (flange) of the pushing member was measured using simulation software (Autodesk Nastran In-CAD) by calculating the force at which the piston breaks from the cross-sectional formula of the piston (breaking load from tensile strength and cross-sectional area). The measurement conditions were as follows: the top of the pushing member was fixed, and a load was applied from the bottom of the support part, and the deformation of each part of the pushing member was confirmed. The maximum displacement from the original position of the bottom of the support part was taken as the deflection, and measurements were taken with and without a tubular member (material A6063-0, inner diameter 10.1 mm, outer diameter 12.1 mm). The pushing member has an outer diameter of 31 mm for the bottomed cylindrical part and 105 mm for the support part. The displacement from the original position of the bottom of the support part was analyzed using the finite element method.

The results of the above experiment are shown below. When the tubular member is provided, even if the thickness of the push-up member is reduced from 3 mm to 2 mm, bending fracture does not occur in the support part of the push-up member, as in the case where the push-up member is made 3 mm thick without the tubular member.

In this way, by providing a tubular member, it was found that it is possible to reduce the impact caused by the operation of the piston member, and even if the thickness of the plastic push-up member is reduced from 3 mm to 2 mm to make it lighter, bending fracture does not occur in the push-up member, and the necessary strength is maintained.

Example 2
An aluminum push-up member, piston member, base (squib holder), and cylinder for a safety device having the same configuration as the above embodiment were prepared, and an experiment was conducted to see whether the shock caused by the actuator's operation could be mitigated by changing the material of the buffer material (flange-shaped protrusion (corresponding to the above modified example) or tubular member (corresponding to the above embodiment)). Note that the gas generator, the gas generating agent and amount of gas used in the gas generator, and the push-up member were all standardized in each experiment. Table 2 below shows the specifications of each member used in the experiment (three samples were prepared for each specification). Note that in Table 2 below, "HT" for temperature refers to a test in a high-temperature environment of 85°C, "stroke" refers to the travel distance of the piston member in the cylinder (the distance from the initial state to the collision with the stopper), and "resin" for the material of the buffer material refers to monomer cast nylon. Specifications A and B are buffer materials consisting of two flange-shaped protrusions (corresponding to the above modified example), and specifications C to L are buffer materials consisting of tubular members (corresponding to the above embodiment). The thickness of the cushioning material of specification A is 1 mm, and the thickness of the cushioning material of specification B is 0.5 mm. The radial size of the cushioning material of specifications C, E, and G is an inner diameter of 10.1 mm and an outer diameter of 12.1 mm, the radial size of the cushioning material of specifications D, F, and H is an inner diameter of 10.1 mm and an outer diameter of 14.1 mm, the radial size of the cushioning material of specifications I and J is an inner diameter of 10 mm and an outer diameter of 16 mm, the radial size of the cushioning material of specification K is an inner diameter of 10 mm and an outer diameter of 15 mm, and the radial size of the cushioning material of specification L is an inner diameter of 10 mm and an outer diameter of 15 mm. Here, for the cushioning material of specification K, two pieces were fitted in the axial direction of the piston member (as two-tiered stacking) for the experiment. For the cushioning material of specification L, four pieces were fitted in the axial direction of the piston member (as four-tiered stacking) for the experiment.

Table 3 below shows the experimental results for each sample of each specification. In Table 3, "total height" refers to the axial length of the piston member, "deformation" refers to the amount of deformation in the axial length of the piston member, and "elongation" refers to the elongation rate from the initial state of the axial length of the piston member after actuation. If fracture occurred in the piston member or base (squib holder) in the first sample of each specification, experiments were not performed on the other two samples.

From Table 3, it was found that for specification A, the impact force during operation is absorbed by shear fracture, allowing normal operation (no breakage of the piston member or base (squib holder)). In contrast, it was found that for specification B, which is half the thickness of specification A, although shear fracture occurs, it is unable to absorb the impact force sufficiently, and the piston member may break. It was also found that for specifications C, E, G, and H, the impact force during operation is absorbed by plastic deformation, allowing normal operation (no breakage of the piston member or base (squib holder)). In contrast, it was found that for specifications D, F, I, J, K, and L, it is unable to absorb the impact force, and there are cases where the base (squib holder) or piston member breaks.

These results show that by using a cushioning material (a flange-shaped protrusion (corresponding to the above modified example) or a tubular member (corresponding to the above embodiment)) designed to adequately absorb the impact force during operation through shear fracture or plastic deformation, it is possible to prevent the piston member or base (squib holder) from breaking.

Reference Signs List 1, 101 Actuator 2, 102 Base 3, 103 Cylindrical member 4 Tubular member 4a, 4b, 10g Tapered portion 5 Holding member 6, 106 Space 10, 110 Piston member 10a, 110a Main body 10b, 110b Rod-shaped portion 10c, 110c Hole 10d, 12a, 110d Female thread 10e, 110e Groove 10f, 110f Reduced diameter portion 11, 12, 111, 112 Seal member 13, 113 Hole 14, 114 Cylinder 14a, 114a Through hole 15, 115 Push-up member 16, 116 Projectile 17, 117 Gas generator 17a, 117a Cup body 18 Container 19 Bottomed cylindrical portion 19a Bottom 20 Support portion 21 Lid portion 23, 123 Stopper members 23a, 23b, 123a, 123b Groove portion 24, 25, 26 Ventilation hole 27 Movement prevention member 30 Air vehicle 31 Airframe 33 Leg portion 40 Connecting member 50 Bolt member 50a Head portion 50b Male thread portion 51, 52, 53 Hole portion 53a Insertion opening 100 Safety devices 110h, 110i Protrusion portion

Claims (6)

An actuator for use in an aircraft safety device,
a sliding member having a main body and a rod-shaped portion connected to the main body and having a width smaller than that of the main body;
a tubular member provided around a portion of the rod portion with one end of the tubular member in contact with the main body;
a cylinder that slidably accommodates the sliding member and the tubular member therein;
a stopper member provided at one end of the cylinder, the stopper member having a hole that causes the sliding member to protrude outward from the inside of the cylinder when actuated, and that limits the movement of the tubular member into the cylinder when actuated;
a power source provided at the other end of the cylinder and configured to generate power for sliding the sliding member;
Equipped with
an actuator , wherein the tubular member is made of a material that undergoes plastic deformation and has a tensile strength lower than that of the sliding member and the stopper member;
a push-up member having a bottomed tubular portion disposed so as to cover at least a portion of the cylinder and a flange-shaped portion formed so as to protrude outward from an opening or a middle portion of a side surface of the bottomed tubular portion, the push-up member being pushed up in one direction by the sliding member;
a projectile that is supported and pushed up by the flange portion of the push-up member;
A safety device comprising : 2. The safety device according to claim 1, characterized in that, during operation, when the tubular member collides with the stopper member and is plastically deformed , the tubular member and the inner wall portion of the cylinder are separated by a predetermined distance or more so that the tubular member does not come into contact with the inner wall portion of the cylinder. 3. The safety device according to claim 1, wherein a tapered portion is formed inside an opening of the tubular member on a side that collides with the stopper member. A sliding member including a main body, a rod-shaped portion that is integral with the main body and has a width smaller than that of the main body, and at least one protrusion that is fixed to a periphery of a part of the rod-shaped portion;
a cylinder that slidably accommodates the sliding member therein;
a stopper member provided at one end of the cylinder, the stopper member having a hole through which the sliding member protrudes outward from the inside when actuated, the stopper member colliding with the protruding portion when actuated;
a power source provided at the other end of the cylinder and configured to generate power for sliding the sliding member;
Equipped with
an actuator, wherein the protrusion is fixed to the rod-shaped portion with such a strength that a portion where the protrusion is fixed to the rod-shaped portion is shear-broken when the protrusion collides with the stopper member during actuation ;
a push-up member having a bottomed tubular portion disposed so as to cover at least a portion of the cylinder and a flange-shaped portion formed so as to protrude outward from an opening or a middle portion of a side surface of the bottomed tubular portion, the push-up member being pushed up in one direction by the sliding member;
a projectile that is supported and pushed up by the flange portion of the push-up member;
A safety device comprising: a ring-shaped seal member that comes into contact with at least a portion of the sliding member is provided on a portion of an inner wall surface of the hole,
The safety device according to any one of claims 1 to 4, characterized in that at least a portion of an outer surface of the sliding member that comes into contact with and rubs against the sealing member when the sliding member is assembled is formed into a smooth shape. The safety device according to any one of claims 1 to 5 is provided,
The flying object is a parachute or a paraglider.

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