Liquid storage container

Abstract

Provided is a liquid storage container in which a device is disposed and with which high durability can be achieved.　This liquid storage container includes: a seamless cylindrical container body in which a storage chamber capable of storing a liquid is provided and which has, on both end sections thereof, an opening for connecting the storage chamber with the outside; and a device which is partially disposed in the storage chamber of the container body and acts on the liquid inside the storage chamber to damp vibration occurring on the liquid surface and / or controls the position of the liquid surface, wherein the device has a pair of fixed parts which are in contact with and fixed to the opening of the container body, and a device part which is supported by the pair of fixed parts and is not directly fixed to the container body.

Description

Technical Field

[0001] The present invention relates to a liquid storage container in which a device is arranged inside. Background Art

[0002] The propulsion device of a liquid rocket includes a propellant tank for storing a liquid propellant, a gas tank for supplying a pressurizing gas to the propellant tank, and a combustion chamber in which the propellant pressurized by the gas supplied from the gas tank and injected from the propellant tank burns. Generally, two types of propellant tanks, one for fuel and the other for oxidizer, are used in this propulsion device, but there is no significant structural difference between these two types of propellant tanks.

[0003] By the way, when the liquid level of the liquid stored inside the propellant tank fluctuates greatly (vibrates) due to the acceleration of the rocket or the like, the fluctuation of this liquid level induces a coupled vibration in a plurality of components constituting the rocket, which is likely to have an adverse effect on the attitude control of the rocket during flight. Therefore, a device including an annular member called a baffle or the like is arranged inside the propellant tank so as to quickly attenuate the vibration of the liquid level. Note that this type of device is fixed to the main body of the propellant tank by welding (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008 - 303956

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when a device is fixed to the propellant tank body by welding, if the body expands or contracts due to heat and pressure, stress concentrates at the welded joint between the body and the device, making it highly likely that this welded joint will break. In addition, since the propellant tank body is constructed by welding together multiple parts to accommodate the device inside, there was also the problem that it could not always be made sufficiently durable.

[0006] Therefore, the object of the present invention is to provide a liquid storage container with a device arranged inside and high durability. [Means for solving the problem]

[0007] According to one aspect of the present invention, a liquid storage container is provided, comprising: a seamless cylindrical container body having a storage chamber inside which a liquid can be stored and openings at both ends connecting the storage chamber to the outside; and a device having a portion of the container body positioned in the storage chamber, which acts on the liquid in the storage chamber to dampen vibrations generated at the liquid surface and / or control the position of the liquid surface, wherein the device has a pair of fixing parts that contact and are fixed to the openings of the container body, and a device part that is supported by the pair of fixing parts and is not directly fixed to the container body.

[0008] In one aspect of the present invention described above, it is preferable that the device portion is directly connected to one of the fixed portions and connected to the other fixed portion via a sliding portion that can slide. Furthermore, it is preferable that the device portion includes a first rib directly connected to one of the fixed portions, a second rib connected to the other fixed portion via the sliding portion in a manner that allows it to slide, a stringer connecting the first rib and the second rib, and a baffle plate fixed to the stringer.

[0009] Furthermore, the fixing part has a cylindrical shaft whose outer surface is in contact with the opening of the container body, and a fitting part having a convex and / or concave portion is provided on the outer surface of the shaft, and it is desirable that the portion of the opening in contact with the outer surface of the shaft is provided with a fitted portion having a shape corresponding to the fitting part. Furthermore, it is preferable that the shaft is provided with a hole connecting the inner space and the outer space of the shaft. [Effects of the Invention]

[0010] In a liquid storage container according to one aspect of the present invention, the cylindrical container body is constructed seamlessly, thus increasing the durability of the container body compared to cases where the container body is constructed by welding together multiple parts.

[0011] Furthermore, in a liquid storage container according to one aspect of the present invention, a pair of fixing parts constituting the device are fixed to openings located at both ends of the container body, and the device parts constituting the device are not directly fixed to the container body. Therefore, unlike cases where the device parts are directly fixed to the container body by welding, even if the container body expands or contracts due to the effects of heat or pressure, stress does not concentrate between the device parts and the container body.

[0012] Therefore, according to one aspect of the present invention, a liquid storage container is provided in which a device is arranged inside and which has high durability. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic cross-sectional view of a liquid storage container. [Figure 2] Figure 2 is a schematic perspective view of the device. [Figure 3] Figure 3 is a schematic cross-sectional view showing the structure of the first fixing part and its surroundings. [Figure 4] Figure 4 is a schematic cross-sectional view showing the second fixing part and the surrounding structure. [Figure 5]Figures 5(A), 5(B), 5(C), 5(D), and 5(E) are schematic cross-sectional views illustrating a method for manufacturing a liquid storage container. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the attached drawings. Figure 1 is a schematic cross-sectional view showing a liquid storage container 2 according to this embodiment. As shown in Figure 1, the liquid storage container 2 includes a seamless cylindrical container body 4. This container body 4 is a single, seamless member (part) constructed in a cylindrical shape from a metal such as aluminum alloy (typically, aluminum alloys of the 2000, 5000, 6000, and 7000 series as defined by JIS), and has a storage chamber 4a inside which liquid can be stored.

[0015] The two ends of the container body 4 (the two ends along the height direction of the cylinder) are both configured as dome shapes that close off the storage chamber 4a. At the positions corresponding to the apex of each end, there is an opening 4b or an opening 4c that connects the outside and inside (storage chamber 4a) of the container body 4. In this embodiment, both the opening 4b and the opening 4c are configured as small-diameter cylindrical shapes that protrude outward.

[0016] Furthermore, the liquid storage container 2 of this embodiment includes a device 6, part of which is positioned in the storage chamber 4a of the container body 4. Figure 2 is a schematic perspective view of the device 6. As shown in Figures 1 and 2, the device 6 has a first fixing part 8 that contacts and is fixed to one opening 4b of the container body 4, and a second fixing part 10 that contacts and is fixed to the other opening 4c of the container body 4.

[0017] The first fixing portion 8 and the second fixing portion 10 support a device portion 12 that functions to attenuate vibrations (waves) generated on the liquid surface by acting on the liquid in the storage chamber 4a and to control the position of the liquid surface. More specifically, the device portion 12 is directly connected to the first fixing portion 8 and is connected to the second fixing portion 10 via a cylindrical sliding plug (sliding portion) 14 that can slide relative to the second fixing portion 10. Although this device portion 12 is supported by the first fixing portion 8 and the second fixing portion 10, it is not directly fixed to the container body 4. Note that the device portion 12 basically does not contact the container body 4, but the container body 4 and the device portion 12 may contact each other.

[0018] FIG. 3 is a cross-sectional view schematically showing the first fixing portion 8 and the structure around it. As shown in FIG. 3, this first fixing portion 8 has a cylindrical (e.g., cylindrical or rectangular cylindrical) shaft 16 that is fixed to the opening 4b in a state of being inserted into the opening 4b such that one end is located inside the storage chamber 4a. The shaft 16 is made of a metal such as an aluminum alloy, and a part of the outer peripheral surface 16a on the other end side of the shaft 16 contacts and is crimped to the opening 4b of the container body 4.

[0019] A fitting portion 16b having convex and concave portions is provided on a part of the outer peripheral surface 16a of the shaft 16 that contacts the opening 4b. Also, a fitting portion 4d having a shape corresponding to the fitting portion 16b is provided on a part of the opening 4b that contacts the outer peripheral surface 16a (fitting portion 16b) of this shaft 16. By fitting the fitting portion 16b into the fitting portion 4d, the first fixing portion 8 is firmly fixed to the container body 4.

[0020] In this way, the shaft 16 is firmly crimped and fixed to the opening 4b by fitting the fitting portion 16b into the fitting portion 4d and is not fixed by welding. In this embodiment, a fitting portion 16b having convex and concave portions is shown, but the fitting portion 16b only needs to have a convex or concave portion (that is, either one).

[0021] Furthermore, the quantity, shape, arrangement, etc. of the convex and concave portions constituting the fitting portion 16b are not limited to the aspects of this embodiment, and can be freely set as long as the function of the fitting portion 16b is not lost. For example, the fitting portion 16b may be constituted by a thread or the like provided on the outer peripheral surface 16a of the shaft 16. In this case, the fitting portion 4d may also be constituted by a thread or the like corresponding to the thread or the like of the fitting portion 16b.

[0022] In addition, a plurality of holes 16c for connecting the space inside the shaft 16 and the space outside are provided in this cylindrical shaft 16. The plurality of holes 16c are arranged, for example, at positions that do not overlap with the fitting portion 16b. However, the plurality of holes 16c may be arranged at positions that overlap with the fitting portion 16b. Furthermore, in this embodiment, a plurality of holes 16c are provided in the shaft 16, but the number of holes 16c provided in the shaft 16 may be one. Also, a thread may be provided on the inner peripheral surface of the shaft 16.

[0023] FIG. 4 is a cross-sectional view schematically showing the second fixing portion 10 and the structure around it. As shown in FIG. 4, this second fixing portion 10 has a cylindrical (for example, cylindrical or rectangular cylindrical) shaft 18 that is fixed to the opening 4c in a state of being inserted into the opening 4c such that one end is located inside the storage chamber 4a. The structure, material, etc. of this shaft 18 are similar to the structure, material, etc. of the shaft 16 that the first fixing portion 8 has. For example, the shaft 18 is constituted by a metal such as an aluminum alloy, and a part of the outer peripheral surface 18a on the other end side of the shaft 18 is in contact with and crimped to the opening 4c of the container body 4.

[0024] A fitting portion 18b having convex and concave portions is provided on a part of the outer peripheral surface 18a of the shaft 18 that contacts the opening 4c. Also, a fitting portion 4e having a shape corresponding to the fitting portion 18b is provided on a part of the opening 4c that contacts the outer peripheral surface 18a (fitting portion 18b) of this shaft 18. By fitting the fitting portion 18b into the fitting portion 4e, the second fixing portion 10 is firmly fixed to the container body 4.

[0025] Thus, the shaft 18 is firmly pressed and fixed to the opening 4c by the fitting portion 18b fitting onto the fitted portion 4e, and is not fixed by welding. In this embodiment, the fitting portion 18b is shown having a convex portion and a concave portion, but the fitting portion 18b only needs to have a convex portion or a concave portion (i.e., one or the other).

[0026] Furthermore, the number, shape, and arrangement of the protrusions and recesses constituting the fitting portion 18b are not limited to the configuration of this embodiment and can be freely set within the limits that do not impair the function of the fitting portion 18b. For example, the fitting portion 18b may be composed of screw threads or the like provided on the outer circumferential surface 18a of the shaft 18. In this case, the fitted portion 4e may also be composed of screw threads or the like corresponding to the screw threads or the like of the fitting portion 18b.

[0027] Furthermore, the cylindrical shaft 18 is provided with a plurality of holes 18c that connect the inner space and the outer space of the shaft 18. The plurality of holes 18c are arranged, for example, in positions that do not overlap with the fitting portion 18b. However, the plurality of holes 18c may be arranged in positions that overlap with the fitting portion 18b. Moreover, although a plurality of holes 18c are provided in the shaft 18 in this embodiment, the number of holes 18c provided in the shaft 18 may be just one. In addition, screw threads may be provided on the inner circumferential surface of the shaft 18.

[0028] A cylindrical sliding plug 14 is inserted into the space inside the shaft 18 from one end of the shaft 18, which is located in the storage chamber 4a. The width (diameter) of the sliding plug 14 is slightly smaller than the width (diameter) of the space inside the shaft 18, and the sliding plug 14 can slide smoothly along the length direction (height direction of the cylinder) of the shaft 18.

[0029] Furthermore, it is desirable that the sliding plug 14 be made of a resin such as a fluoropolymer to prevent ignition of the stored liquid due to spark generation or temperature rise caused by contact with the shaft 18. However, the material constituting the sliding plug 14 is not limited to resin. The sliding plug 14 may be made of any material that allows for appropriate operation in relation to the material of the shaft 18 and the stored liquid.

[0030] As shown in Figures 1, 2, and 3, the device portion 12 has four first ribs 20, one end of which is fixed to the shaft 16 of the first fixing portion 8. Each first rib 20 is made of a metal such as aluminum alloy or stainless steel, and is constructed in an arc shape and plate shape along the dome-shaped end of the container body 4.

[0031] The surface tension acting between each first rib 20 and the liquid controls the liquid level in the storage chamber 4a. The four first ribs 20 are fixed to the shaft 16 by welding or other means such that the angle between two adjacent first ribs 20 is approximately equal.

[0032] Furthermore, as shown in Figures 1, 2, and 4, the device portion 12 has a rib fixing device 24 that is attached to the sliding plug 14 by screws 22 or the like. The rib fixing device 24 is cylindrical in shape and made of a metal such as aluminum alloy or stainless steel. One end of each of the four second ribs 26 is fixed to this rib fixing device 24.

[0033] Each second rib 26 is constructed from a metal such as aluminum alloy or stainless steel, and is in the shape of a plate with a larger radius of curvature (a gently curved arc) compared to the first rib 20. The four second ribs 26 are fixed to the rib fixing device 24 by welding or other methods such as so that the angle between two adjacent second ribs 26 is approximately equal.

[0034] Furthermore, the device section 12 has four stringers 28 that connect the other end of each first rib 20 to the other end of the corresponding second rib 26. Each stringer 28 is made of a metal such as aluminum alloy or stainless steel and is cylindrical or rectangular (long plate) in shape. One end of each stringer 28 is fixed to the other end of the corresponding first rib 20 by welding or other means.

[0035] Furthermore, the other end of each stringer 28 is fixed to the other end of the corresponding second rib 26 by welding or other means. As a result, the four stringers 28 are positioned between the four first ribs 20 and the four second ribs 26 such that their respective longitudinal directions (the height direction of the cylinder or rectangular prism) are roughly parallel to each other.

[0036] In this embodiment, the device section 12 is connected to the four first ribs 20 and the four second ribs 26 by four stringers 28. However, the shape, number, arrangement, etc., of the first ribs 20, second ribs 26, stringers 28, etc., can be changed according to the specifications of the liquid storage container 2. For example, the first ribs 20 and second ribs 26 may be hollowed out.

[0037] Furthermore, the first rib 20, the second rib 26, the stringer 28, etc., may be molded integrally. Moreover, the device portion 12 does not necessarily have to include the first rib 20, the second rib 26, and the stringer 28. For example, the device portion 12 may have a columnar (cylindrical) portion that passes through the central axis of the container body 4.

[0038] The device section 12 has three baffle plates 30 arranged at arbitrary intervals along the longitudinal direction of the four stringers 28. Each baffle plate 30 is made of a metal such as aluminum alloy or stainless steel, and is constructed in an annular and plate shape, and is fixed to the stringer 28 by welding or other methods. Vibrations generated at the surface of the liquid stored in the storage chamber 4a are quickly dampened by colliding with these baffle plates 30.

[0039] In this embodiment, the device section 12 has three annular, plate-shaped baffle plates 30 fixed to four stringers 28. However, the shape, number, and arrangement of the baffle plates 30 can be changed according to the specifications of the liquid storage container 2. For example, the baffle plates 30 may be hollowed out. Also, the baffle plates 30 do not necessarily have to be fixed to the stringers 28. For example, if the device section 12 has a columnar (cylindrical) portion passing through the central axis of the container body 4, the baffle plates 30 may be fixed to this columnar (cylindrical) portion.

[0040] The liquid storage container 2 of this embodiment, configured in this way, has high durability and can withstand use in harsh environments, including outer space. Typically, the liquid storage container 2 is used as a propellant tank for a liquid rocket. In this case, for example, gas supplied from outside the container body 4 (such as a gas tank that supplies pressurizing gas) flows into the storage chamber 4a through the hole 18c of the shaft 18, increasing the pressure inside the storage chamber 4a.

[0041] When the pressure in the storage chamber 4a is increased, the liquids such as fuel and oxidizer stored in the storage chamber 4a are pushed out and discharged to the outside of the container body 4 through the hole 16c of the shaft 16 at the other end of the shaft 16. Also, when storing liquids such as fuel and oxidizer in the storage chamber 4a, the liquid supplied from outside the container body 4 flows into the storage chamber 4a through the hole 16c of the shaft 16 or the hole 18c of the shaft 18. However, the functions of shafts 16 and 18 may be swapped or changed depending on the manner of use.

[0042] Next, the method for manufacturing the liquid storage container 2 described above will be explained. Figures 5(A), 5(B), 5(C), 5(D), and 5(E) are schematic cross-sectional views illustrating the method for manufacturing the liquid storage container 2. In the method for manufacturing the liquid storage container 2 according to this embodiment, as shown in Figure 5(A), first, the device portion 12 (first rib 20, rib fixing device 24, second rib 26, stringer 28, and baffle plate 30) fixed to the shaft 16 of the first fixing portion 8 is inserted into the space inside the cylindrical member 42 which will become the container body 4.

[0043] The first fixing jig 101 is inserted into the shaft 16. The first fixing jig 101 is then temporarily fixed to the device part 12 (for example, the rib fixing device 24) from the shaft 16 side. The second fixing jig 103 is inserted into the shaft 18 of the second fixing part 10, which is not connected to the device part 12.

[0044] The second fixing jig 103 is then temporarily fixed to the device portion 12 (for example, the rib fixing jig 24) from the opposite side of the shaft 16. The shaft 18 is fixed to the second fixing jig 103, for example, by applying pressure from the inside of the shaft 18 using the second fixing jig 103. However, the method of fixing the shaft 18 to the second fixing jig 103 is not limited to this embodiment.

[0045] Subsequently, as shown in Figure 5(B), with the shaft 16 side of the cylindrical member 42 heated by the burner flame 105 or the like, inward pressure is applied to this part from the outside. For example, pressure is applied to the cylindrical member 42 by rotating the protruding metal member 107 coaxially with the cylindrical member 42 and pressing the metal member 107 against the cylindrical member 42.

[0046] As a result, the end of the cylindrical member 42 on the shaft 16 side is formed into a dome shape, and a cylindrical opening 4b with a smaller diameter than the original cylindrical member 42 is formed. At the same time, a fitted portion 4d is formed in the opening 4b, which has a shape that matches the shape of the fitting portion 16b of the shaft 16.

[0047] Similarly, as shown in Figure 5(C), when the shaft 18 side of the cylindrical member 42 is heated by the burner flame 109 or the like, inward pressure is applied to this part from the outside. For example, pressure is applied to the cylindrical member 42 by rotating the protruding metal member 111 coaxially with the cylindrical member 42 and pressing the metal member 111 against the cylindrical member 42.

[0048] As a result, the end of the cylindrical member 42 on the shaft 18 side is formed into a dome shape, and a cylindrical opening 4c with a smaller diameter than the original cylindrical member 42 is formed. At the same time, a fitted portion 4e is formed in the opening 4c, which has a shape that matches the shape of the fitting portion 18b of the shaft 18. In this embodiment, the opening 4c is formed after the opening 4b is formed, but the opening 4b may be formed after the opening 4c is formed.

[0049] After the container body 4 is formed by the process described above, the first fixing jig 101 and the second fixing jig 103 are removed from the device part 12, as shown in Figure 5(D). Then, the first fixing jig 101 and the second fixing jig 103 are pulled out from the shaft 16 and the shaft 18.

[0050] Subsequently, as shown in Figure 5(E), the sliding plug 14 is inserted into the shaft 18 and fixed to the rib fixing device 24 by fastening or other means, thereby completing the liquid storage container 2. In order to avoid deformation of the sliding plug 14 due to the heat applied during the manufacturing of the liquid storage container 2, it is desirable that the sliding plug 14 be inserted into the shaft 18 in the final step. However, if the sliding plug 14 is made of a heat-resistant material, the sliding plug 14 may be inserted into the shaft 18 before the cylindrical member 42 etc. are heated.

[0051] As described above, in the liquid storage container 2 of this embodiment, the container body 4 is constructed seamlessly. Therefore, the durability of the container body 4 is higher compared to cases where the container body 4 is constructed by welding together multiple parts.

[0052] Furthermore, in the liquid storage container 2 of this embodiment, the first fixing part 8 (shaft 16) and the second fixing part 10 (shaft 18) that constitute the device 6 are fixed to openings 4b and 4c located at both ends of the container body 4, and the device part 12 that constitutes the device 6 is not directly fixed to the container body 4. Therefore, unlike when the device part 12 is fixed to the container body 4 by welding, even if the container body expands or contracts due to the effects of heat and pressure, stress does not concentrate at the contact fixing part between the device part 12 and the container body 4.

[0053] Furthermore, in the liquid storage container 2 of this embodiment, the device portion 12 constituting the device 6 is directly connected to the first fixed portion 8 (shaft 16) and is also connected to the second fixed portion 10 (shaft 18) via a sliding plug (sliding portion) 14 that can slide against it. Therefore, even if each part expands or contracts due to temperature changes, the sliding plug 14 slides, mitigating the effects of expansion or contraction.

[0054] Furthermore, the present invention is not limited to the embodiments described above and can be implemented with any modifications. For example, not only the baffle plate 30, but also other members (parts) such as the first rib 20 and the second rib 26 that constitute the device portion 12 may have the function of damping vibrations generated at the surface of the liquid.

[0055] Furthermore, not only the first rib 20, but also other components (parts) constituting the device portion 12, such as the second rib 26, stringer 28, and baffle plate 30, may have the function of controlling the liquid level by surface tension. Also, for example, parts with a diameter smaller than the inner diameter of the opening 4c, such as the shaft 18 and sliding plug 14, may be inserted into the opening 4c and fixed in place at any step after the molding of the container body 4 (typically the final step).

[0056] Furthermore, the structures, methods, etc., of the embodiments described above can be modified as needed, as long as they do not deviate from the scope of the present invention. [Explanation of Symbols]

[0057] 2. Liquid storage container 4. Container body 4a Storage Room 4b opening 4c opening 4d Mated part 4e Mated part 6 devices 8 1st fixed part 10 Second fixed part 12 Device section 14. Sliding plug (sliding part) 16 shafts 16a Outer surface 16b Mating part 16c hole 18 shafts 18a Outer surface 18b Mating part 18c hole 20. First Rib 22 screws 24 Rib fasteners 26. Second Rib 28 Stringer 30 baffle board 42 Cylindrical member

Claims

1. A seamless cylindrical container body having a storage chamber inside capable of storing liquid, and openings at both ends connecting the storage chamber to the outside, The container body includes a device which is partially positioned in the storage chamber and acts on the liquid in the storage chamber to dampen vibrations generated at the liquid surface and / or to control the position of the liquid surface, The device is A pair of fixing parts that contact and secure the opening of the container body, A liquid storage container having a device portion supported by a pair of fixed portions and not directly fixed to the container body.

2. The liquid storage container according to claim 1, wherein the device portion is directly connected to one of the fixed portions and connected to the other fixed portion via a sliding portion that can slide.

3. The liquid storage container according to claim 2, wherein the device portion comprises a first rib directly connected to one of the fixed portions, a second rib connected to the other fixed portion via a sliding portion that can slide, a stringer connecting the first rib and the second rib, and a baffle plate fixed to the stringer.

4. The fixing part has a cylindrical shaft whose outer surface is in contact with the opening of the container body. A fitting portion having a convex and / or concave portion is provided on a part of the outer surface of the shaft. A liquid storage container according to any one of claims 1 to 3, wherein the portion of the opening that contacts the outer surface of the shaft is provided with a fitted portion having a shape corresponding to the fitting portion.

5. The liquid storage container according to claim 4, wherein the shaft is provided with a hole connecting the inner space and the outer space of the shaft.

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