Collision protection for small, high-speed missiles

Abstract

To provide a collision protective body for a small high-speed flying object capable of reducing a through-hole area when the small high-speed flying object penetrates a protective plate, and capable of reducing a quantity of a newly generated front ejector.SOLUTION: The protective plate is made of an aluminum-based metal, a magnesium-based metal, a titanium-based metal, or a composite metal thereof, and includes an equivalent strain introduction portion formed by HPS working. The equivalent strain introducing part of the protective plate is formed in a vertical and horizontal lattice shape composed of a vertical lattice and a horizontal lattice having a predetermined width formed in parallel at a predetermined interval, and the predetermined width is a width not less than the predetermined interval.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a collision protection for small high-speed flying objects. [Background technology]

[0002] Space debris is non-functioning man-made objects orbiting the Earth, and can be anything from large pieces of post-operational satellites to smaller pieces of these and paint chips.

[0003] The problem with this type of space debris is that it moves at extremely high speeds. For example, space debris orbiting in low orbit, about 300 to 450 km above the Earth's surface, moves at speeds ranging from the first cosmic velocity of 7.9 km / s to the second cosmic velocity of 11.2 km / s.

[0004] The average speed at which space debris collides with an operational satellite is thought to be around 10 km / s, and in such cases, the satellite will suffer damage according to the magnitude of the kinetic energy, with its functionality being reduced or it being completely destroyed.

[0005] Therefore, measures to prevent collisions with space debris are extremely important in future space development, and different countermeasures are being adopted for each spacecraft, such as artificial satellites, rockets, and planetary probes.

[0006] As an example, the International Space Station (ISS), which is in operation at the time of filing this application, classifies the size of space debris into three types as a measure to prevent collisions with space debris: large debris of 10 cm or more, medium-sized debris of 1 cm to 10 cm, and small debris of 1 cm or less, and has established response policies for each type.

[0007] Of these categories, for large space debris over 10 cm, the trajectory is predicted in advance using ground-based radar, and the trajectory is changed in advance to avoid collisions. Furthermore, for medium-sized space debris between 1 cm and 10 cm, there is a risk that it may penetrate the pressurized wall of the space station, but since the probability of this happening is relatively low, if the pressurized wall is damaged, it will be repaired by extravehicular activity.

[0008] However, compared to these relatively large pieces of space debris, the orbits of small pieces of space debris less than 1 cm (hereinafter referred to as small debris) are difficult to predict, and there are a great many of them, so the probability of collision is much higher. Therefore, it is difficult to avoid them in advance like large pieces of space debris, and it is not realistic to perform extravehicular activities every time there is a collision, as is the case with medium-sized pieces of space debris.

[0009] However, since such small debris usually has a small mass and often less kinetic energy than larger space debris, a debris bumper device known as a Whipple shield or stuffing Whipple shield is installed outside the pressurized wall as a collision protection device, and by colliding with this, penetration of the pressurized wall is prevented (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-121476 Summary of the Invention [Problem to be solved by the invention]

[0011] The debris bumper device described above protects the pressurized wall by causing small debris to collide with a protective plate made of a metal plate, absorbing and dispersing the energy. To help understand the structure, the structure of a Whipple shield, an example of a debris bumper device, is shown in Figure 17.

[0012] As shown in Figure 17(a), the Whipple shield 100 used on the International Space Station is composed of a protective plate 102 placed in front of a pressurized wall 101 and an impact protection body 104 made of multi-layer insulation material 103.

[0013] When small debris 105 collides and penetrates the protective plate 102 as shown in Figure 17(b), a rear ejecta 106 (rear ejecta) is generated on the side of the protective plate 102 where the protected object (here, the pressurized wall 101 of the International Space Station) exists (hereinafter referred to as the protected side), and a front ejecta 107 (front ejecta) is generated on the side from which the small debris 105 is approaching (hereinafter referred to as the approaching side, including when the approaching object is a small, high-speed flying object as described below).

[0014] At this time, the rear ejecta 106 becomes a debris cloud and is rendered harmless by being captured by the multi-layer insulation material 103. However, the front ejecta 107 is released back into space and becomes new space debris.

[0015] As mentioned above, the problem of space debris is extremely serious, and it is necessary to prevent further increases as much as possible. Therefore, when designing satellites and other devices, we must ensure that the generation of space debris due to the release or fragmentation of parts is minimized.

[0016] However, the reduction of the front ejector has not yet been fully investigated.

[0017] Furthermore, this problem is not limited to debris bumpers that provide protection against small man-made debris. For example, impact shields that provide protection against space debris and other incoming objects not resulting from human activity, which are small, generally less than 1 cm in size, and have a relative speed exceeding 1 km / s that they encounter in extraterrestrial regions, such as outer space or the surface of an extraterrestrial planet, at altitudes of 100 km or more (hereinafter collectively referred to as "small, high-speed extraterrestrial projectiles"), such as those used in planetary exploration rovers, also have the same problem from the perspective of preventing the diffusion of extraplanetary materials.

[0018] Furthermore, the same applies to collision protection devices that provide protection against flying objects with relative velocities exceeding 1 km / s that are encountered in terrestrial regions at altitudes less than 100 km above the Earth's surface (hereinafter collectively referred to as terrestrial small high-speed flying objects), such as sniper rifle bullets and debris generated by missiles and railguns. In the following explanation, extraterrestrial small high-speed flying objects and terrestrial small high-speed flying objects are collectively referred to as small high-speed flying objects. The term small high-speed flying object also includes flying objects in the hypervelocity region.

[0019] The present invention has been made in consideration of the above circumstances, and provides an impact protector for small, high-speed projectiles that can reduce the area of ​​the through hole when a small, high-speed projectile penetrates the protective plate and reduce the amount of newly generated forward ejecta. [Means for solving the problem]

[0020] In order to solve the above-mentioned conventional problems, the collision protector for small high-speed flying objects according to the present invention (1) has a protective plate made of an aluminum-based metal, a magnesium-based metal, a titanium-based metal, or a composite metal of these, which is equipped with an equivalent strain introduction section formed by HPS processing.

[0021] The impact protection body for a small high-speed flying object according to the present invention also has the following features. (2) The equivalent strain introduction portion of the protective plate is in the form of a vertical and horizontal grid consisting of vertical and horizontal grids of a predetermined width formed in parallel at a predetermined interval. (3) The predetermined width is equal to or greater than the predetermined interval. (4) The collision protection for small high-speed flying objects comprises a first protective plate that is positioned relatively on the approaching side of the flying object, and a second protective plate that is positioned relatively on the protecting side, and is configured by superimposing the lattice intersection portions of the second protective plate on the lattice mesh portions of the first protective plate.

[0022] Furthermore, in the present invention, aluminum-based metals, magnesium-based metals, titanium-based metals, or composite metals of these metals to which equivalent strain has been introduced by HPS processing are used as protective plate materials in collision protection bodies for small high-speed flying objects. [Effects of the Invention]

[0023] The collision protector for small, high-speed projectiles according to the present invention has a protective plate made of an aluminum-based metal, a magnesium-based metal, a titanium-based metal, or a composite metal of these, which is equipped with an equivalent strain introduction section produced by HPS processing. This makes it possible to provide a collision protector for small, high-speed projectiles which reduces the area of ​​the through hole when a small, high-speed projectile penetrates the protective plate and reduces the amount of newly generated forward ejecta.

[0024] Furthermore, if the equivalent strain introduction portion of the protective plate is in the form of a vertical and horizontal grid consisting of vertical and horizontal grids of a specified width formed in parallel at a specified interval, the processing area can be reduced and the process can be simplified compared to when HPS processing is applied to the entire metal body, and the propagation of cracks that occur when a small, high-speed flying object collides with the protective plate can be suppressed compared to when HPS processing is not applied.

[0025] Furthermore, if the predetermined width is equal to or greater than the predetermined interval, further improvement in protective performance can be expected.

[0026] Furthermore, the collision protection for small, high-speed flying objects comprises a first protective plate that is positioned relatively closer to the incoming flying object and a second protective plate that is positioned relatively closer to the protected side, and by overlapping the lattice intersections of the second protective plate with the lattice sections of the first protective plate, it is possible to limit small, high-speed flying objects that penetrate the protective plates to those with a specified angle of incidence and to make the collision protection object thinner.

[0027] Furthermore, according to the present invention, aluminum-based metals, magnesium-based metals, titanium-based metals, or composite metals of these metals, to which considerable strain has been introduced by HPS processing, are used as the protective plate material in the collision protection body for small high-speed projectiles. This reduces the area of ​​the through hole when a small high-speed projectile penetrates the protective plate, and also reduces the amount of newly generated forward ejecta. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of an HPS processing device. [Figure 2] FIG. 2 is an explanatory diagram illustrating a configuration of a verification unit. [Figure 3] FIG. 10 is an explanatory diagram showing the results of a tensile test. [Figure 4] FIG. 1 is an explanatory diagram showing an experimental device for a collision experiment. [Figure 5] FIG. 10 is an explanatory diagram showing experimental results regarding through holes in a collision experiment. [Figure 6] FIG. 10 is an explanatory diagram showing experimental results regarding through holes in a collision experiment. [Figure 7] 10A and 10B are explanatory diagrams showing experimental results of a front ejector in a collision experiment. [Figure 8] 10A and 10B are explanatory diagrams showing experimental results of a front ejector in a collision experiment. [Figure 9] FIG. 10 is an explanatory diagram showing the experimental results of the pressurized wall simulation plate (rear wall) in the collision experiment. [Figure 10] FIG. 10 is an explanatory diagram relating to the relationship between through holes and yield stress. [Figure 11] FIG. 10 is an explanatory diagram relating to the relationship between through holes and yield stress. [Figure 12] 10A to 10C are explanatory diagrams showing the process of producing a protection plate in the second embodiment. [Figure 13] 10A to 10C are explanatory diagrams showing the process of producing a protection plate in the second embodiment. [Figure 14] 10A to 10C are explanatory diagrams showing the process of producing a composite protection plate in the third embodiment. [Figure 15] FIG. 2 is an explanatory diagram showing the configuration of a composite protective plate. [Figure 16] FIG. 2 is an explanatory diagram showing the XX cross section. [Figure 17] FIG. 1 is an explanatory diagram showing a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention relates to an impact protection for small, high-speed projectiles equipped with a metal protective plate, and provides an impact protection for small, high-speed projectiles that reduces the area of ​​the through hole when the small, high-speed projectile penetrates the protective plate and can reduce the amount of newly generated forward ejecta.

[0030] In this specification, a small, high-speed flying object is a flying object that is small, approximately 1 cm or less in size, as described above, and has a relative velocity of at least 1 km / s, regardless of whether it originates from human activity, and includes, for example, small debris and space dust encountered in outer space or on the surface of an extraterrestrial planet or in their vicinity, as well as fragments generated by missiles or railguns on Earth.

[0031] The impact protection device is a component equipped with a metal protective plate for protecting the vehicle from small, high-speed flying objects, and the vehicle to which it is attached is not particularly limited. For example, for use in extraterrestrial regions, the vehicle to which it is attached may be a spacecraft such as an artificial satellite, the International Space Station, a rocket, or a planetary probe, or a planetary exploration rover operating on an extraterrestrial planet, and the impact protection device functions as a debris bumper for these. For use on Earth, the vehicle may be armor for vehicles or buildings, a shield, a bulletproof vest, or the like, and the impact protection device functions as a bumper for these small pieces flying at high speeds.

[0032] The collision protector for small high-speed flying objects according to this embodiment is characterized by having a protective plate made of an aluminum-based metal, a magnesium-based metal, a titanium-based metal, or a composite metal of these, which has an equivalent strain introduction section formed by HPS processing.

[0033] HPS processing is a metal processing method using the HPS (High-Pressure Sliding) method, in which a metal body is clamped between upper and lower dies under pressure, and the upper and lower dies are slid relatively (linear one-way movement or reciprocating movement) in a direction approximately perpendicular to the pressure direction, thereby imparting a considerable strain to the metal body.

[0034] In addition, the HPS method can be said to be a method for introducing equivalent strain, which includes an introduction step in which an equivalent strain introduction section is formed between one side of a metal body following the first clamping body and the other side of a metal body following the second clamping body, as the clamping bodies, which are sandwiched between them, move linearly relative to each other in a direction approximately perpendicular to the pressure direction of the clamping bodies.

[0035] The metals that make up the protective plates that are the subject of HPS processing are aluminum-based metals, magnesium-based metals, titanium-based metals, or composite metals of these, and are not particularly limited as long as they are metals that can be given significant strain due to relative positional changes under the clamping pressure caused by HPS processing.

[0036] The aluminum-based metal means aluminum or an aluminum alloy, and as the aluminum alloy, for example, a 6000 series aluminum alloy can be suitably used.

[0037] Furthermore, the magnesium-based metal refers to a magnesium alloy, and for example, AZ31, AZ61, or AZ91 can be suitably used.

[0038] Furthermore, titanium-based metal means titanium or a titanium alloy, and examples of titanium alloys that can be suitably used include Ti-6Al-4V, Ti-6Al-7Nb, and titanium-molybdenum alloys.

[0039] Furthermore, by constructing an impact protection body for small, high-speed flying objects using a protective plate with such a configuration, it is possible to reduce the area of ​​the through hole when a small, high-speed flying object penetrates the protective plate, and also to reduce the amount of newly generated forward ejecta.

[0040] In addition, the collision protection body for small high-speed flying objects according to this embodiment is also characterized in that the equivalent strain introduction portion of the protection plate is in the form of a vertical and horizontal lattice, consisting of vertical and horizontal lattices of a predetermined width formed in parallel at a predetermined interval.

[0041] The method for forming the vertical and horizontal lattice-shaped equivalent strain introduction section in the protective plate is not particularly limited as long as it is a method for introducing equivalent strain by HPS processing. For example, as shown in JP 2019-034336 A, the incremental feeding high-pressure sliding (IF-HPS) method can be adopted, which can form continuous or intermittent equivalent strain introduction sections in the target metal body by repeating the HPS processing and incremental feeding operation.

[0042] For example, by using the sequential HPS method to form multiple parallel equivalent strain introduction sections in a vertical lattice pattern on a protective plate, and then forming multiple parallel equivalent strain introduction sections in a horizontal lattice pattern, it is possible to create a protective plate with equivalent strain introduction sections in a vertical and horizontal lattice pattern.

[0043] Furthermore, with this configuration, the process can be simplified by reducing the processing area compared to when HPS processing is applied to the entire metal body, and the propagation of cracks that occur when a small, high-speed flying object collides with the protective plate can be suppressed compared to when HPS processing is not applied.

[0044] Furthermore, the vertical lattice-shaped equivalent strain introducing portions and the horizontal lattice-shaped equivalent strain introducing portions are each formed with a predetermined width and at predetermined intervals, but this predetermined width may be greater than or equal to the predetermined intervals. If the width of the equivalent strain introducing portions is formed to be the same as or wider than the intervals, further improvement in protective performance can be expected.

[0045] Furthermore, the protective plates that constitute the collision protection for small high-speed flying objects, such as protective plates equipped with equivalent strain introduction sections in the form of vertical and horizontal lattices as described above, may be used to provide protection against incoming small high-speed flying objects with a single plate, but they may also be used to provide protection with at least two protective plates, a first protective plate and a second protective plate.

[0046] In this case, the first protective plate may be positioned relatively on the side from which the flying object is approaching, and the second protective plate may be positioned relatively on the protection side, and the grid intersections of the second protective plate may be overlapped with the grid portions of the first protective plate.

[0047] By adopting such a configuration, it is possible to limit small high-speed projectiles that penetrate the protective plate to those with a predetermined angle of incidence, and to make the collision protection body thinner.

[0048] The impact protector for a small, high-speed flying object according to this embodiment will be further described below with reference to drawings, test results, etc. Note that in the following examples, the small, high-speed flying object will be mainly described as an extraterrestrial small, high-speed flying object, but the present invention is not limited to extraterrestrial use. However, when the applicant files a patent for this application, the applicant may limit the use of the present invention to extraterrestrial or terrestrial use.

[0049] 1. First embodiment In the first embodiment, a collision protector for a small high-speed flying object using one protective plate will be described.

[0050] (1) Creating a protective plate Aluminum alloy A6061-T6 plate material, which is used for debris bumpers on the International Space Station, was used and subjected to HPS processing to form a significant strain introduction section.

[0051] Specifically, using the HPS processing device shown in Figure 1, a 70mm x 70mm x 1mm thick A6061-T6 sheet was clamped at a stress of 1 GPa while undergoing a 10mm linear sliding process in one direction, creating a corresponding strain-introducing region throughout the sheet. In the following explanation, a metal sheet subjected to the above-described processing conditions will be referred to as "X10-1P (1 GPa)." To further illustrate the point, a sheet clamped at a stress of 1 GPa and subjected to a 5mm linear sliding process twice in one direction (reciprocating motion) will be referred to as "X5-2R (1 GPa)."

[0052] (2) Construction of collision protection structure Next, using X10-1P (1 GPa) in which the equivalent strain introduction section was formed as described above, a collision protector A for a small high-speed flying object was constructed.

[0053] Specifically, a small-scale debris bumper, which is the collision protection structure A1 according to the first embodiment, was constructed as part of the configuration of a verification unit 10 (see FIG. 2(a)) that can be used in a collision test, which will be described later.

[0054] As shown in Figure 2(b), this verification unit 10 is configured by fixing a forward verification plate 11, a protective plate B, a rear wall 12, and a rear verification plate 13 at a predetermined interval from the flying side to the protected side using cut bolts 14.

[0055] The forward verification plate 11 is a copper plate (C1100-1 / 4H) that is 150 mm long x 150 mm wide and 2 mm thick, and is a witness plate for capturing and observing the forward ejecta generated by the collision between the small high-speed flying object C and the protective plate B. In addition, a hole 11a with a diameter of 30 mm is drilled in the center of the forward verification plate 11 to allow the small high-speed flying object C to pass through.

[0056] The protective plate B is a plate for protecting the rear wall 12, which is the object to be protected, by impacting it with a small high-speed projectile C. In this example, X10-1P (1 GPa) with an equivalent strain introduction section formed is used as the protective plate B1. The distance K1 from the forward verification plate 11 to the protective plate B is 50 mm.

[0057] The rear wall 12 is a wall that should be protected from penetration by a small high-speed flying object C by a protective plate B. Here, a piece of A2024-T3 material measuring 200 mm in length, 200 mm in width, and 3.0 mm in thickness is placed to simulate the pressurized wall of the International Space Station. The distance K2 from the protective plate B to the rear wall 12 is set to 100 mm.

[0058] The rear verification plate 13 is a copper plate (C1100-1 / 4H) that is 200 mm long x 200 mm wide and 2 mm thick, and is a witness plate for capturing and observing the ejecta generated by the collision between the small high-speed projectile C and the protective plate B when it penetrates the rear wall 12.

[0059] Then, a protective plate B was placed in front of the rear wall 12 to be protected to construct a collision protection body A1, and further, along with a front verification plate 11 and a rear verification plate 13, cut bolts 14 were passed through the corners of each of these plates, and each plate was fixed in the desired position with a nut to form a verification unit 10.

[0060] According to the configuration of the collision protection body A1, since it has a protection plate B made of an aluminum-based metal with an equivalent strain introduction section formed by HPS processing, it is possible to provide a collision protection body for small high-speed projectiles that reduces the area of ​​the through hole when a small high-speed projectile penetrates the protection plate and also reduces the amount of newly generated forward ejecta.

[0061] [2. First Test] In the first embodiment described above, the configuration of the collision protection body A1 was explained, using a protective plate B1 with a resistance of X10-1P (1 GPa) as the protective plate B. In this section, we will next explain the study conducted on the protective capability of the collision protection body A for small high-speed flying objects, focusing on the effect of reducing the area of ​​the through-hole when the protective plate B is penetrated and the effect of reducing the amount of forward ejecta, while referring to the results obtained from tensile tests and collision tests conducted on the protective plate B1 and various other protective plates B created separately.

[0062] (1) Creating a protective plate Using the same method as for the production of the aforementioned X10-1P (1 GPa), two more HPS-processed metal plates, X5-1P (1 GPa) and X10-2R (1 GPa), were produced, and protective plate B2 (X5-1P (1 GPa)) and protective plate B3 (X10-2R (1 GPa)) were made from these.

[0063] (2) Tensile test (conditions and equipment configuration) Using a universal testing machine (Shimadzu Corporation), tensile tests were performed on the metals used in the protective plates B1 to B3, namely, X10-1P (1 GPa) (protective plate B1), X5-1P (1 GPa) (protective plate B2), and X10-2R (1 GPa) (protective plate B3). The tensile speed during measurement was 0.6 mm / min. The test specimens were dumbbell-shaped, with a total length of 40 mm, a width of 12 mm, a thickness of 1 mm, a parallel portion length of 8 mm, a width of 3 mm, and a measurement temperature of 22°C. For comparison, tests were also performed on aluminum alloy A6061-T6.

[0064] (3) Tensile test results Figure 3 shows the nominal stress-nominal strain curve. Tensile tests revealed that the yield stress of aluminum alloy A6061-T6 was 290 MPa. Among X10-1P (1 GPa), X5-1P (1 GPa), and X10-2R (1 GPa), even X5-1P (1 GPa), which showed the lowest yield stress on the graph, had a yield stress of 340 MPa, which was 1.15 times that of A6061-T6. These results demonstrate that X10-1P (1 GPa) (protective plate B1), X5-1P (1 GPa) (protective plate B2), and X10-2R (1 GPa) (protective plate B3) all have higher yield stresses than aluminum alloy A6061-T6.

[0065] (4) Collision test (conditions and equipment configuration) Next, for each of the protective plates B1 (X10-1P (1 GPa)), B2 (X5-1P (1 GPa)), and B3 (X10-2R (1 GPa)), a verification unit 10 shown in Figure 2 was constructed, and impact tests were conducted using the two-stage light gas gun shown in Figure 4. The projectile used for the impact was a sphere made of aluminum alloy A2017-T4, with a diameter of 3.2 mm.

[0066] (5) Collision test results (through hole) Figure 5 shows the results of the impact test on the through hole. First, for the aluminum alloy (A6061-T6) used for comparison, the projected area of ​​the through hole was 25.2 mm 2 It was.

[0067] In contrast, the projected area of ​​the through holes in each of the protective plates B1 to B3 is 22.1 mm for protective plate B1 (X10-1P (1GPa)). 2 , protective plate B2 (X5-1P (1GPa)) is 20.4mm 2 , Protective plate B3 (X10-2R (1GPa)) is 16.8 mm 2 Both were smaller than when an aluminum alloy (A6061-T6) was used as the target.

[0068] These results show that by using aluminum-based metals with considerable strain introduced by HPS processing as protective plate materials, it is possible to reduce the area of ​​the penetration hole when a small, high-speed projectile penetrates the protective plate.

[0069] Furthermore, similar changes in metal properties occur with HPS processing in magnesium-based metals, titanium-based metals, and composite metals containing at least two selected from aluminum-based metals, magnesium-based metals, and titanium-based metals. Therefore, it is thought that the area of ​​the penetration hole when a small, high-speed projectile penetrates a protective plate can also be reduced for these metals.

[0070] The state of the through holes is shown in Figure 6. Figures 6(a) and 6(b) show the impact surface and back surface of aluminum alloy A6061-T6, respectively, while Figures 6(c) and 6(d) show the impact surface and back surface of protective plate B1 (X10-1P (1GPa)), a representative example of a metal protective plate that has been subjected to HPS processing.

[0071] As can be seen from Figure 6, there was no significant difference in the appearance of the through holes when comparing the aluminum alloy A6061-T6 protective plate and the metal protective plate with HPS processing.

[0072] (6) Crash test results (front ejector) Figures 7 and 8 show the crash test results for front ejectors. Figure 7 is an explanatory diagram showing the size measurement method and the cumulative number distribution of front ejectors. As shown in the graph on the right side of Figure 7, by applying HPS processing, the cumulative number of front ejectors 0.5 mm or larger was slightly reduced. The number of long ejectors also slightly decreased.

[0073] Furthermore, the weight of the front ejector was slightly reduced by applying HPS processing, as shown in Fig. 8. However, no difference in the number of ejectors was observed depending on the sliding distance of the HPS processing.

[0074] These results show that by using aluminum-based metals with considerable strain introduced by HPS processing as protective plate materials, it is possible to reduce the amount of forward ejecta generated when a small, high-speed projectile penetrates the protective plate.

[0075] Furthermore, similar changes in metal properties occur with HPS processing in magnesium-based metals, titanium-based metals, and composite metals containing at least two selected from aluminum-based metals, magnesium-based metals, and titanium-based metals. Therefore, it is thought that the amount of forward ejecta generated when a small, high-speed projectile penetrates a protective plate can also be reduced for these metals.

[0076] (7) Crash test results (observation of pressurized wall) Figure 9 shows the surface condition of the pressurized wall simulation plate, i.e., the rear wall 12 in Figure 2. Observation of plate B1 (X10-1P (1 GPa)) revealed that the projectile had fragmented and the rear ejecta had been dispersed over a relatively wide area. However, the dispersion areas of other HPS-treated metal plates, such as plate B2 (X5-1P (1 GPa)) and plate B3 (X10-2R (1 GPa)), were smaller in extent than plate B1 (X10-1P (1 GPa)).

[0077] Furthermore, compared to protective plate B2 (X5-1P (1GPa)), protective plate B1 (X10-1P (1GPa)) broke the projectiles into small pieces and dispersed them over a wide area, which meant that the impact of the collision was also dispersed over a wide area, and it was therefore thought that protective performance was superior.

[0078] (8) Examination of the relationship between through holes and yield stress Next, the relationship between the size of the through holes in protective plates B1 to B3 obtained through the collision test and the yield stress of the metal bodies that make up these protective plates was examined.

[0079] Data on the size of the through-hole and yield stress for each metal are shown in Figure 10. As shown in the lower half of the table, we investigated the relationship between the size of the through-hole and yield stress for protective plate B1 (X10-1P (1 GPa)), protective plate B2 (X5-1P (1 GPa)), and protective plate B3 (X10-2R (1 GPa)).

[0080] In addition, in this study, as shown in the upper half of the table, four types of 6000 series aluminum alloys with different yield stresses were also studied in order to compare with these protective plates B1 to B3.

[0081] Figure 11 is a graph showing the relationship between through-hole size and yield stress. The black circles in the graph represent A6061-T6, the triangles represent three 6000-series aluminum alloys for comparison, and the white circles represent protective plates B1 to B3. The vertical axis represents the projected area of ​​the through-hole (Hp) divided by the projected area of ​​the projectile (Ap), and the horizontal axis represents yield stress.

[0082] As can be seen from Figure 11, the HPS-processed X10-1P (1 GPa) (protective plate B1), X5-1P (1 GPa) (protective plate B2), and X10-2R (1 GPa) (protective plate B3) were plotted on the extension line of the four aluminum alloys (A6061-T6, 6000 series aluminum alloys A, B, and C) used as comparison controls.

[0083] In addition, the projected area of ​​the through holes was closely related to the yield stress, and it seemed that the breaking elongation was not significantly affected.

[0084] As described above, the collision protector for small, high-speed flying objects according to this embodiment has a protective plate made of an aluminum-based metal, a magnesium-based metal, a titanium-based metal, or a composite metal of these, which is equipped with an equivalent strain introduction section produced by HPS processing. This makes it possible to provide a collision protector for small, high-speed flying objects that reduces the area of ​​the through hole when a small, high-speed flying object penetrates the protective plate and reduces the amount of newly generated forward ejecta.

[0085] 3. Second Embodiment Next, we will explain the impact protection for small high-speed projectiles according to the second embodiment. The impact protection for small high-speed projectiles according to the second embodiment is similar to the first embodiment in that it is an impact protection for small high-speed projectiles using a single protective plate, but differs in that the equivalent strain introduction portion due to HPS processing is formed in a vertical and horizontal lattice pattern rather than over the entire protective plate.

[0086] (1) Creating a protective plate The formation of lattice-shaped equivalent strain introduction portions in a metal plate can be carried out using an IF-HPS processing device. The original plate 20 used as the metal plate can be an A6061-T6 material with a thickness of about several mm (e.g., 1 mm). While clamping and compressing this original plate 20 with a stress of 1 GPa or more, equivalent strain introduction portions are first formed in either the vertical or horizontal direction (here, the vertical direction) as shown in FIG. 12(a). Note that, as an example, the lattice width of the equivalent strain introduction portions and the spacing between the equivalent strain introduction portions can be approximately the same, e.g., 5 to 30 mm.

[0087] 12(a), a first pass (P1) is performed in the vertical direction at the position of the first row formation target virtual line L1 using the IF-HPS processing device, forming equivalent strain introduced portion L1P1. Here, the processing length for one pass of the IF-HPS processing device is shorter than the vertical length of the original sheet 20, so that equivalent strain introduced portion L1P1 alone does not form a longitudinal equivalent strain introduced portion.

[0088] Next, as shown in Figure 12(b), a second pass (P2) is performed in the vertical direction at the position of the first row formation target virtual line L1, partially overlapping with the equivalent strain introduction portion L1P1, to form the equivalent strain introduction portion L1P2.

[0089] Even with the formation of this equivalent strain introduction portion L1P2, a longitudinal equivalent strain introduction portion has not yet been formed. Therefore, an nth processing pass (Pn) is performed in the vertical direction at the position of the first row formation target virtual line L1, and the formation of the equivalent strain introduction portion L1Pn is repeated to form a longitudinal equivalent strain introduction portion. In this case, the nth processing pass is performed while partially overlapping with the equivalent strain introduction portion L1Pn-1 formed by the n-1th processing pass (Pn-1), thereby forming a longitudinal equivalent strain introduction portion without any gaps. In this case, by forming the equivalent strain introduction portion L1P3 in the third processing pass (P3), a longitudinal equivalent strain introduction portion is formed along the first row formation target virtual line L1, as shown in Figure 12(c).

[0090] After the formation of the first row is completed, as shown in FIG. 12(d), a first pass (P1) is performed in the vertical direction at the position of the virtual line L2 for forming the second row, thereby forming equivalent strain-introducing portions L2P1.

[0091] As in the first row, as shown in Figure 12(e), an equivalent strain introduction portion L2P2 is formed by the second pass processing (P2), and an equivalent strain introduction portion L2Pn (here, equivalent strain introduction portion L2P3) is formed by the nth pass processing (here, the third pass processing), thereby forming a longitudinal equivalent strain introduction portion along the second row formation target virtual line L2.

[0092] Similarly, as shown in Figure 12(f), a longitudinal equivalent strain introduction portion is formed along the desired mth row formation target virtual line Lm (here, the fifth row formation target virtual line L5), such as the third row formation target virtual line L3 and the fourth row formation target virtual line L4, to create a vertical grid plate (horizontal grid plate) 21 in which the equivalent strain introduction portion is formed in a vertical grid pattern.

[0093] Next, equivalent strain introduction parts are formed in a lattice pattern in either the horizontal or vertical direction (here, the horizontal direction) by the same method on the thus-prepared vertical lattice plate (horizontal lattice plate) 21 while being clamped under a stress of 1 GPa. Note that, as an example, the lattice width of the equivalent strain introduction parts and the formation interval of the equivalent strain introduction parts are approximately the same, and can be, for example, 5 to 30 mm.

[0094] Specifically, as shown in Figures 13(a) to 13(f), a vertical and horizontal lattice plate 22 is formed in which an equivalent strain introduction portion is formed in a vertical and horizontal lattice pattern consisting of vertical and horizontal lattices, through a process of forming an equivalent strain introduction portion similar to that of the vertical lattice plate (horizontal lattice plate) 21.

[0095] In the example shown in this section, the vertical and horizontal lattice plates 22 are longitudinal and transverse equivalent strain introducing portions, respectively, but they do not necessarily have to be formed longitudinally and transversely, and are not limited to this. The length of the equivalent strain introducing portion can be changed as necessary.

[0096] Furthermore, when forming one equivalent strain introduction portion that constitutes the lattice, when processing is performed using multiple passes, the processing of the next pass (e.g., P2) is made to partially overlap with the processing portion of the previous pass (e.g., L1P1), but this is not limited to this, and processing can also be performed so that there is no overlap.

[0097] Furthermore, although one equivalent strain introduction portion that constitutes the lattice was formed by processing using multiple passes, this is not limited to this, and if a processed portion of sufficient length can be formed in one pass, one equivalent strain introduction portion that constitutes the lattice may be formed in one pass.

[0098] In the above example, the lattice-shaped equivalent strain introduction parts are formed on the entire surface of the original sheet 20, but this is not limitative. For example, the lattice-shaped equivalent strain introduction parts may be formed so as to be scattered at a predetermined density on the original sheet 20, as in the case of a lattice-shaped kasuri pattern.

[0099] (2) Construction of collision protection structure The vertical and horizontal lattice plate 22 created as described above can be assembled as a protection plate B of the verification unit 10 shown in FIG. 2(b) to construct a collision protection body A having the vertical and horizontal lattice plate 22.

[0100] With this type of collision protection body A, the process can be simplified by reducing the processing area compared to when HPS processing is applied to the entire metal body, and the propagation of cracks that occur when a small, high-speed flying object collides with the protection plate can be suppressed compared to when HPS processing is not applied.

[0101] 4. Third Embodiment Next, a description will be given of a collision protector for a small high-speed flying object according to a third embodiment. The collision protector for a small high-speed flying object according to the third embodiment is similar to the second embodiment in that it is a collision protector for a small high-speed flying object that uses vertical and horizontal lattice plates 22 as protection plates, but differs in that it is a collision protector for a small high-speed flying object that uses two vertical and horizontal lattice plates 22.

[0102] (1) Construction of collision protection structure As shown in Figure 14(a), by using two vertical and horizontal lattice plates 22 created in the second embodiment, it is possible to construct an impact protection body for small high-speed flying objects equipped with two protection plates, a first protection plate 31 and a second protection plate 32.

[0103] Both protective plates 31, 32 are made with the same width and spacing of the equivalent strain introduction section, but to make it easier to understand the overlapping relationship of the equivalent strain introduction sections, the equivalent strain introduction section of the first protective plate 31 is shown with diagonal hatching, and the equivalent strain introduction section of the second protective plate 32 is shown with vertical or horizontal hatching.

[0104] Furthermore, of the equivalent strain introduction portions of the first protective plate 31 indicated by diagonal hatching, the portion indicated by diagonal lines going up to the right is an equivalent strain introduction portion SR formed in the vertical direction, the portion indicated by diagonal lines going up to the left is an equivalent strain introduction portion SL formed in the horizontal direction, and the portion indicated by the intersection of the diagonal lines going up to the right and the diagonal lines going up to the left is a double equivalent strain introduction portion SRL in which an equivalent strain introduction portion has been formed in the horizontal direction in addition to the equivalent strain introduction portion formed in the vertical direction (double equivalent strain introduction has been performed).

[0105] Similarly, of the equivalent strain introduction portions of the second protective plate 32 indicated by hatching with vertical or horizontal lines, the portion indicated by horizontal lines is an equivalent strain introduction portion SV formed in the vertical direction, the portion indicated by vertical lines is an equivalent strain introduction portion SH formed in the horizontal direction, and the portion indicated by the intersection of horizontal and vertical lines is a double equivalent strain introduction portion SVH in which an equivalent strain introduction portion has been formed in the horizontal direction in addition to the equivalent strain introduction portion formed in the vertical direction (double equivalent strain introduction has been performed).

[0106] Furthermore, with regard to the first protective plate 31 and the second protective plate 32, the portions where no equivalent strain introduction portion is formed, which correspond to the mesh portions of the vertical and horizontal lattice, are shown as unprocessed portions O.

[0107] With regard to such a first protective plate 31 and second protective plate 32, one protective plate is superimposed on the other protective plate as shown in Figure 14(b) (here, the second protective plate 32 is superimposed on the first protective plate 31) to construct a composite protective plate 33 as shown in Figure 14(c).

[0108] Here, the first protective plate 31 and the second protective plate 32 are overlapped by matching the double equivalent strain introducing portions SVH, which are the lattice intersections of the second protective plate 32, with the unprocessed portions O, which are the lattice portions of the first protective plate 31. In other words, the double equivalent strain introducing portions SRL, which are the lattice intersections of the first protective plate 31, with the unprocessed portions O, which are the lattice portions of the second protective plate 32. Note that in Figure 14(c), the first protective plate 31 and the second protective plate 32 are positioned with a large offset to help understand the structure of the composite protective plate 33, but it goes without saying that they may be overlapped more efficiently.

[0109] When the first protective plate 31 and the second protective plate 32 are arranged in this manner, a composite protective plate 33 is constructed which has four types of overlapping sections in a plan view: overlapping section SRLO, overlapping section OSVH, overlapping section SRV, and overlapping section SLH, as shown surrounded by dashed lines in Figure 15.

[0110] The overlapping section SRLO is an overlapping section composed of the double equivalent strain introduction section SRL of the first protective plate 31, shown by hatching with intersecting diagonal lines going up to the right and down to the left, and the unprocessed section O of the second protective plate 32, shown in white.

[0111] The overlapping section OSVH is an overlapping section made up of the unprocessed portion O of the first protective plate 31 shown in white and the double equivalent strain introduction portion SVH shown by hatching with crossing horizontal and vertical lines.

[0112] In addition, the overlapping sections SRLO and OSVH are overlapping sections composed of a section in either the first protective plate 31 or the second protective plate 32 where double equivalent strain has been introduced (double equivalent strain introduction section SRL, double equivalent strain introduction section SVH), and a section in either the other which is the unprocessed section O.

[0113] In addition, the overlapping section SRV is an overlapping section composed of the equivalent strain introduction section SR of the first protective plate 31, indicated by hatching with diagonal lines slanting upward to the right, and the equivalent strain introduction section SV of the second protective plate 32, indicated by hatching with horizontal lines.

[0114] The overlapping section SLH is an overlapping section composed of the equivalent strain introduction section SL of the first protective plate 31, indicated by hatching with diagonal lines slanting upward to the left, and the equivalent strain introduction section SH of the second protective plate 32, indicated by hatching with vertical lines.

[0115] In addition, the overlapping sections SRV and SLH are overlapping sections composed of an equivalent strain introduction section (equivalent strain introduction section SR, SL, SV, SH) of either the first protective plate 31 or the second protective plate 32 and an equivalent strain introduction section (equivalent strain introduction section SR, SL, SV, SH) of the other.

[0116] The obtained composite protective plate 33 can be assembled as the protective plate B of the verification unit 10 shown in Fig. 2(b) to construct a collision protective body A having the composite protective plate 33. Note that the area outside the overlapping region indicated by the dashed line in Fig. 15 may be removed as necessary.

[0117] (2) Behavior of flying objects and protective plates The composite protective plate 33 constructed in this manner can have a thinner thickness required to attenuate the energy of a projectile by a predetermined amount, compared to an unprocessed plate (unprocessed plate).

[0118] Furthermore, as shown by the dashed frame in Figure 15, when viewed in a plane, the composite protective plate 33 appears at first glance to have equivalent strain introduction sections formed over almost the entire surface, but none of the first protective plates 31 or second protective plates 32 before being stacked have equivalent strain introduction sections formed over the entire surface without any gaps, so the composite protective plate can be manufactured with significantly less effort than the effort required to process plates in which equivalent strain introduction sections have been formed without any gaps.

[0119] Therefore, as described above, the composite protective plate 33 constructed in this manner is not only capable of reducing the thickness required to attenuate the energy of the projectile by a predetermined amount compared to an unprocessed plate (unprocessed plate), but is also characterized in that this can be achieved without processing to form a significant strain introduction section without gaps on the entire surface.

[0120] Fig. 16 is an explanatory diagram showing a cross section of a protective plate. Fig. 16(a) shows a cross section of an unprocessed plate, and Fig. 16(b) shows a cross section of a composite protective plate 33 in which overlapping sections including an unprocessed portion O are continuous, for example, cross section XX in Fig. 15.

[0121] As an example, consider a small, high-speed projectile C1 that strikes a protective plate 34 made of an unprocessed plate perpendicularly as shown in Figure 16(a), and assume that the thickness of the protective plate 34 required to penetrate the small, high-speed projectile C1 while attenuating the energy of the small, high-speed projectile C1 by a predetermined amount is P1.

[0122] Next, considering the case of the composite protective plate 33 shown in Figure 16(b), for example, the overlapping section OSVH shown at the bottom of the figure is a section that has a double equivalent strain introduction section SVH that has been subjected to equivalent strain introduction processing in addition to the unprocessed section O, and therefore can more efficiently attenuate the energy of a small high-speed flying object C2 that is incident perpendicularly than in the case of a protective plate 34 that is composed entirely of unprocessed section O in the thickness direction.

[0123] Therefore, the thickness P2 of the composite protection plate 33 required to attenuate a predetermined amount of energy can be made smaller than the thickness P1 of the protection plate .

[0124] The same applies to the overlapping section SRLO shown in the middle of Fig. 16(b). That is, since the overlapping section SRLO is also a section having the double equivalent strain introducing section SRL, the thickness P2 of the composite protective plate 33 required to attenuate a predetermined amount of the energy of the small high-speed flying object C3 incident perpendicularly can be made smaller than the thickness P1 of the protective plate 34.

[0125] Furthermore, when considering a path that does not pass through the equivalent strain introduction section, a case such as that of the small high-speed projectile C4, which is incident obliquely from the overlapping section OSVH to the overlapping section SRLO, can be considered.

[0126] However, even in such a case, the length that must be traveled before penetration is longer, so energy attenuation can be achieved in the same way as with an unprocessed plate with thickness P1. For example, in the case of a small high-speed projectile C4 that is incident at an angle of 45 degrees, without any angle toward the depth of the page, thickness P2 can be made thinner than thickness P1, as long as thickness P2 is equal to or greater than the quotient of thickness P1 divided by the square root of 2.

[0127] In this way, the composite protective plate 33 can not only be thinner in thickness to attenuate the energy of the projectile by a predetermined amount compared to the unprocessed protective plate 34 (unprocessed plate) in which no equivalent strain introduction section is formed, but also achieves this without processing to form equivalent strain introduction sections without gaps on the entire surface.

[0128] Finally, the above-described embodiments are merely examples of the present invention, and the present invention is not limited to the above-described embodiments. Therefore, even if the embodiments are different from those described above, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical concept of the present invention. [Explanation of symbols]

[0129] 20 Original Plate 22 Vertical and horizontal grid board 31 1st protection plate 32 2nd protection plate 33 Composite protection plate 34 Protective plate A Collision protector for small high-speed flying objects B Protective plate C Small high-speed flying object K1 interval K2 interval L1Pn equivalent strain introduction section L2Pn equivalent strain introduction section Lm Virtual target line O Unprocessed part SR, SL, SV, SH equivalent strain introduction section OSVH overlapping section SLH overlapping compartment SRLO overlapping section SRV overlapping section SRL Double equivalent strain introduction section SVH double equivalent strain introduction part

Claims

1. An impact protection body for small high-speed flying objects, which has a protective plate made of aluminum-based metal, magnesium-based metal, titanium-based metal, or a composite metal of these, with an equivalent strain introduction section created by HPS processing.

2. 2. The impact protection body for a small high-speed flying object according to claim 1, wherein the equivalent strain introduction portion of the protective plate is in the form of a vertical and horizontal lattice consisting of vertical and horizontal lattices having a predetermined width and formed in parallel at a predetermined interval.

3. 3. The collision protector for a small high-speed flying object according to claim 2, wherein the predetermined width is equal to or greater than the predetermined interval.

4. The small high-speed flying object collision protector includes a first protective plate disposed relatively on the approaching side of the flying object, and a second protective plate disposed relatively on the protecting side, 4. The collision protector for a small high-speed flying object according to claim 3, wherein the second protective plate is overlapped with the lattice intersections of the first protective plate so as to correspond to the lattice portions of the first protective plate.

5. Use of aluminum-based metals, magnesium-based metals, titanium-based metals or composite metals of these, to which considerable strain has been introduced by HPS processing, as a protective plate material in a collision protector for small high-speed flying objects.

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