Can

Abstract

This invention provides a technique for reducing the possibility of gaps forming between the two ends of a hoop layer and a spiral layer in a can. The can comprises: a liner having a cylindrical main body with a central axis and domes disposed at both ends of the main body; and a reinforcing layer disposed on the liner and comprising fibers, the reinforcing layer having a hoop layer disposed on the main body and spiral layers disposed throughout the hoop layer and the domes, the hoop layer having a hoop body layer and a hoop end layer connected to the hoop body layer and located at an end along the axial direction of the central axis, the hoop end layer being a shape that protrudes radially outward from the hoop body layer towards the main body, having an outermost apex in the radial direction and a slope extending from the apex towards the outer surface of the domes and following the shape of the outer surface.

Description

Technical Field

[0001] This disclosure relates to technology for tanks used to contain fluids. Background Technology

[0002] Conventionally, tanks for storing fuel used in natural gas vehicles, fuel cell vehicles, etc., are known (Patent Document 1). Existing tanks have a liner and a reinforcing layer disposed on the liner. The reinforcing layer has a sheet layer (also called a hoop layer) disposed on the straight part of the liner and a helical layer disposed on the sheet layer and the dome of the liner. The helical layer is formed by spirally winding fibers onto the sheet layer and the dome. The two ends of the sheet layer are shaped to follow the outer surface of the dome.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-223569

[0004] Helical winding for forming a spiral layer is performed while the fiber is under tension. However, in the prior art, it is possible that the desired tension cannot be applied to the two ends of the sheet layer. In this case, a gap will form between the sheet layer and the spiral layer, which may result in the can's strength not being improved. Summary of the Invention

[0005] This disclosure can be implemented in the following ways.

[0006] (1) According to a first aspect of this disclosure, a can is provided for containing fluid internally. The can comprises: a liner having a cylindrical main body with a central axis and dome-shaped ends disposed at both ends of the main body; and a reinforcing layer disposed on the liner and comprising fibers, the reinforcing layer having a hoop layer disposed on the main body and a spiral layer disposed throughout the hoop layer and the dome-shaped ends, the hoop layer having a hoop body layer and a hoop end layer, the hoop end layer being connected to the hoop body layer and located at an end along the axial direction of the central axis, the hoop end layer having a shape that protrudes radially outward from the hoop body layer towards the main body, having an outermost vertex located in the radial direction and a slope extending from the vertex towards the outer surface of the dome-shaped ends and along the outer surface. According to this method, by having a shape that protrudes radially outward from the hoop body layer, the degree of inclination of the slope relative to the axial direction is greater than in the case where the hoop end layer does not protrude radially outward from the hoop body layer. Therefore, when the fiber is wound around the inclined surface of the ring end layer by helical winding, the dispersion of the force pressing the fiber towards the ring end layer can be suppressed, thus allowing the desired tension to be applied to the fiber. Consequently, since the degree of adhesion between the helical layer and the ring layer can be increased by the pressing force of the fiber towards the ring end layer corresponding to the desired tension, the possibility of gaps forming between the helical layer and the ring layer (especially the ring end layer) can be reduced.

[0007] (2) In the above-described manner, in the cross-section of the can cut by a plane passing through and parallel to the central axis, the distance between the inclined planes can be greater than or equal to the width of the fiber bundle used to form the spiral layer. According to this method, since more pressing force corresponding to the desired tension applied to the fiber bundle during spiral winding can be applied to the inclined planes, the degree of adhesion between the spiral layer and the ring end layer can be improved. Therefore, the possibility of gaps forming between the spiral layer and the ring layer (especially the ring end layer) can be further reduced.

[0008] (3) In the above-described manner, the distance between the radially apex and the outer surface of the main body can be 1.05 to 1.10 times the thickness of the main ring layer. According to this method, the degree of inclination of the inclined plane relative to the axial direction can be large enough to suppress the dispersion of the force that presses the fibers toward the ring end layer side during helical winding, and by suppressing the degree of protrusion of the ring end layer toward the radially outward side, deformation of the helical layer can be suppressed.

[0009] (4) In the above manner, the outer surfaces of the inclined surface and the dome can be formed into iso-tension curved surfaces. According to this method, since the unevenness of the tension applied to the fibers of the reinforcing layer formed on the inclined surface and the outer surface of the dome can be reduced, the strength of the tank can be further improved.

[0010] (5) In the above manner, the ring layer can be formed by a cylindrical component formed by winding the fibers around a component different from the lining. According to this method, the ring layer can be easily formed by a cylindrical component.

[0011] This disclosure can be implemented in various ways, including, in addition to the methods described above, a method for manufacturing a tank, a vehicle equipped with a tank, etc. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the can.

[0013] Figure 2 This is a diagram used to further illustrate the can.

[0014] Figure 3 It is a process diagram showing the manufacturing method of the can.

[0015] Figure 4 This is an explanatory diagram for process P10.

[0016] Figure 5 This is a cross-sectional view of the mandrel before processing, obtained through the extraction process.

[0017] Figure 6 This is a cross-sectional view of the front ring hoop layer.

[0018] Figure 7 This is a schematic diagram showing the ring-shaped layers formed on the main stem.

[0019] Figure 8 This diagram is used to illustrate low-angle helical winding.

[0020] Figure 9 This diagram is used to illustrate high-angle helical winding.

[0021] Figure 10 This is a diagram used to illustrate the reference example of the can.

[0022] Figure 11 This diagram is used to further explain the spiral layer formation process.

[0023] Explanation of reference numerals in the attached figures:

[0024] 10, 10t…can; 14…first metal ferrule part; 14a…opening; 15…second metal ferrule part; 20…reinforcing layer; 25…reservoir; 40…lining; 42…main body; 42fa…outer surface; 44…first dome; 44fa…outer surface; 46…second dome; 50…reinforcing layer; 51…ring body layer; 52, 52t…ring end layer; 53…ring layer; 53fa…sloping surface; 53tfa…sloping surface; 54…middle part; 54p…apex part; 55…ring base end; 57…ring front end; 57p…end; 58…spiral layer; 60…sheet fiber; 62…ring layer before processing; 63…ring layer before configuration; 70…mandrel; 80…fiber bundle; AX…central axis; DAx…axial direction; FD…winding direction; Rg…region. Detailed Implementation

[0025] A. Implementation method:

[0026] Figure 1 This is a cross-sectional view of the tank 10 in this embodiment. Figure 1 This shows a cross-section (prescribed cross-section) of the tank 10 when it is cut along a plane passing through and parallel to the central axis AX of the main body 42 of the tank 10. The tank 10 is used to contain high-pressure fluid. In this embodiment, the tank 10 contains high-pressure fuel gas used in fuel cell vehicles, etc. The tank 10 includes a liner 40, a reinforcing layer 50 disposed on the liner 40, a first metal opening 14, and a second metal opening 15. The first metal opening 14 has an opening 14a that communicates between the interior and exterior of the tank 10. The second metal opening 15 does not have an opening 14a.

[0027] The liner 40 is a hollow container with an internally formed receiving chamber 25 for containing fluid. The liner 40 is formed, for example, of a gas-barrier resin such as polyamide resin. Alternatively, the liner 40 may be formed of metal instead of resin. The liner 40 comprises: a cylindrical main body 42 having a central axis AX, and a pair of domes 44, 46 disposed at both ends of the main body 42. One of the domes 44, 46 is also referred to as the first dome 44, and the other as the second dome 46. The first dome 44 is connected to the end of one of the main bodies 42 along the axial direction DAx of the central axis AX. The second dome 46 is connected to the other end of the main body 42 along the axial direction DAx. The first dome 44 and the second dome 46 are dome shapes whose outer diameter decreases as they move away from the main body 42 along the axial direction DAx.

[0028] The reinforcing layer 50 is a layer used to reinforce the lining 40. The reinforcing layer 20 covers the outer surface of the lining 40. The reinforcing layer 20 contains fibers. In this embodiment, the reinforcing layer 20 is formed from carbon fiber bundles pre-impregnated with a thermosetting resin such as epoxy resin.

[0029] Figure 2 This is a diagram used to further illustrate tank 10. Figure 2 schematically shown Figure 1 The area of ​​the tank 10 shown includes the boundary between the main stem 42 and the first dome 44. Since the area including the boundary between the main stem 42 and the second dome 46 also has the same structure, the area including the boundary between the main stem 42 and the first dome 44 will be used to describe the detailed structure of the tank 10 below.

[0030] The reinforcing layer 50 has a hoop layer 53 disposed on the main body 42 and a spiral layer 58 disposed over the hoop layer 53 and the dome 44. The winding direction of the fibers constituting the hoop layer 53 is along the circumferential direction of the main body 42. That is, the angle between the winding direction of the fibers of the hoop layer 53 and the axial direction DAx is approximately 90°. In this embodiment, the hoop layer 53 is formed by disposing of a cylindrical component, formed by winding sheet-like fibers impregnated with thermosetting resin around a component different from the lining 40, on the main body 42 of the lining 40. The details of the method for forming the hoop layer 53 will be described later. The spiral layer 58 is formed by winding a fiber bundle impregnated with thermosetting resin in a manner that covers the hoop layer 53, the first dome 44, and the second dome 46 under a predetermined tension. The spiral layer 58 is formed by repeatedly winding the fiber bundle around the can 10 using at least one of low-angle spiral winding and high-angle spiral winding. The details of the formation method of spiral layer 58 will be described later.

[0031] The hoop layer 53 comprises a hoop main body layer 51 with a certain thickness and hoop end layers 52. The distance between the outer surface 42fa of the main body 42 and the outer surface of the hoop main body layer 51 in the radial direction of the main body 42, i.e., the thickness of the hoop main body layer 51, is the thickness Tb. The hoop end layers 52 are two layers located at both ends of the hoop main body layer 51 along the axial direction DAx. Here, one of the two hoop end layers 52 located at both ends will be described, but the structure of the other hoop end layer 52 is the same. The hoop end layers 52 are connected to the hoop main body layer 51 and are located at the ends along the axial direction DAx in the hoop layer 53.

[0032] The hoop end layer 52 is a convex shape that protrudes radially outward from the main body layer 51 of the hoop. Specifically, the hoop end layer 52 has a radially outermost vertex portion 54p, i.e., a thickest intermediate portion 54 in the hoop end layer 52, a hoop base end portion 55 connecting the intermediate portion 54 to the hoop main body layer 51, and a hoop front end portion 57 located on the opposite side of the hoop base end portion 55 across the intermediate portion 54 in the axial direction DAx. The thickness of the hoop base end portion 55 gradually increases in the axial direction DAx as it moves from the hoop main body layer 51 toward the intermediate portion 54. The outer surface of the hoop base end portion 55 is an inclined surface with respect to the axial direction DAx, for example, a curved surface. The thickness of the hoop front end portion 57 gradually decreases in the axial direction DAx as it moves away from the intermediate portion 54, i.e., toward the dome (here, the first dome 44). The outer surface of the front end 57 of the ring, i.e., the inclined surface 53fa, extends from the apex 54p toward the outer surface 44fa of the dome (here, the first dome 44) and is inclined relative to the axial direction DAx. The boundary between the inclined surface 53fa and the outer surface 44fa forms a smooth curved surface without a step difference. That is, the inclined surface 53fa extends the shape of the outer surface 44fa in a manner that has the same relationship as the shape of the outer surface 44fa, and is a curved surface shape along the shape of the outer surface 44fa. In this embodiment, the inclined surface 53fa and the outer surface 44fa of the dome (here, the first dome 44), located on the same side in the axial direction DAx, form an iso-tension curved surface. Preferably, in Figure 2 In the specified cross-section of the can 10 shown, the distance Lt of the inclined surface 53fa is greater than or equal to the width Wt of the fiber bundle used to form the spiral layer 58. The distance Lt is the distance along the inclined surface 53fa from the apex 54p to the end 57p on the dome side (here, the first dome 44) of the inclined surface 53fa. Therefore, since the entire width of the fiber bundle can be arranged on the inclined surface 53fa during spiral winding, more pressure corresponding to the desired tension applied to the fiber bundle can be applied to the inclined surface 53fa. This further improves the tightness of the contact between the spiral layer 58 and the ring end layer 52.

[0033] Furthermore, it is preferable that the maximum thickness of the hoop end layer 52, i.e., the distance Ta between the radially apex 54p of the main stem 42 and the outer surface 42fa of the main stem 42, is at least 1.05 times the thickness Tb of the hoop main body layer 51. This allows the inclination of the inclined surface 53fa relative to the axial direction DAx to be large enough to suppress the dispersion of forces pressing the fiber bundle towards the hoop end layer 52 during helical winding. Furthermore, it is preferable that the distance Ta is at least 1.10 times the thickness Tb. This suppresses the radially outward protrusion of the hoop end layer 52, thereby suppressing deformation of the fiber bundle 80 constituting the helical layer 58.

[0034] Figure 3 This is a process diagram illustrating the manufacturing method of the can 10. In the manufacturing method of this embodiment, after the ring hoop layer 53 is formed on the lining 40, a spiral layer forming process is performed to arrange spiral layers 58 on the ring hoop layer 53 and on the dome tops 44 and 46.

[0035] In the ring layer forming process, the first step is a winding process (process P10) in which the sheet fibers are wound around a mandrel (cored bar) with a rigidity higher than that of the lining by 40.

[0036] Figure 4 This is an explanatory diagram of process P10. In process P10, a mandrel 70, which is a component different from the liner 40, is first prepared as the pre-processing ring layer 62. The mandrel 70 is formed of a metal such as stainless steel, iron, or copper and has a cylindrical shape. The outer diameter of the mandrel 70 is slightly larger than the outer diameter of the main body 42 of the liner 40 (for example, about 0.5 mm larger). In addition, the length of the mandrel 70 along the axis AX is longer than the length of the main body 42 of the liner 40. In this embodiment, the rigidity of the mandrel 70 is higher than that of the liner 40.

[0037] If a mandrel 70 is prepared, the sheet fiber 60 impregnated with thermosetting resin is then wound multiple times along the circumference of the mandrel 70 using a sheet winding method (hereinafter referred to as the "SW method"), thereby completing the pre-processing ring layer 62. In this embodiment, the width of the sheet fiber 60 is the same as the length along the axial direction DAx of the main body 42 of the lining 40. When winding the sheet fiber 60 onto the mandrel 70, a predetermined tension is applied to the sheet fiber 60. In the SW method, the tension applied per unit width of the sheet fiber 60 is, for example, about twice the tension applied to the fiber bundle in a general fiber winding method (hereinafter referred to as the FW method).

[0038] After the pre-processing ring layer 62 is completed, the next step is to pull out the mandrel 70 from the pre-processing ring layer 62. Figure 3 Process P20). Process P20 is also called the pull-out process.

[0039] Figure 5 This is a cross-sectional view of the pre-processing annular layer 62 of the mandrel 70, obtained through a pull-out process. (See image below.) Figure 5 As shown, the pre-processing ring layer 62 after the mandrel 70 is pulled out is cylindrical.

[0040] After the pull-out process, the pre-processing ring layer 62 is processed to form the pre-processing ring layer 63, which is a cylindrical component having a ring body layer 51 and a ring end layer 52. Figure 3 Process P30). Process P30 is also referred to as the processing process.

[0041] Figure 6This is a cross-sectional view of the front ring layer 63. In the machining process, the ring layer 62 is machined by cutting and grinding to make the shape of the front ring layer 62 become the shape of the ring layer 53.

[0042] After the processing steps, a step is performed to embed the lining 40 into the front hoop layer 63. Figure 3 The process P40 is also referred to as the embedding process. Through this embedding process, the front hoop layer 63 is disposed on the main body 42 of the lining 40 to become the hoop layer 53.

[0043] Figure 7 This is a schematic diagram showing the formation of a ring layer 53 on the main body 42 of the liner 40 through an embedding process. After the embedding process, a process is performed in which pressure is applied to the interior of the liner 40 through the first metal opening 14 to bring the outer surface 42fa of the main body 42 of the liner 40 into close contact with the inner surface of the ring layer 53. Figure 3 Process P50). Process P50 is also called the pressurization process.

[0044] Following the pressurization process, the helical layer formation process (process P60) is performed while maintaining pressure on the interior of the lining 40. In the helical layer formation process, fiber bundles impregnated with thermosetting resin are first wound multiple times on the lining 40 using the FW method, thereby forming a helical layer 58 consisting of multiple layers. Helical winding is performed using at least one of high-angle helical winding and low-angle helical winding. In this embodiment, a combination of high-angle helical winding and low-angle helical winding is used to form the helical layer 58.

[0045] Figure 8 This diagram is used to illustrate low-angle helical winding. Figure 9 This diagram is used to illustrate high-angle helical winding. (Example) Figure 8 As shown, in low-angle spiral winding, the fiber bundle 80 is repeatedly wound into a spiral shape with the fiber bundle 80 supported on two domes 44 and 46. In the layer formed by low-angle spiral winding, the angle α1 between the winding direction of the fiber bundle 80 and the axial direction DAx is, for example, any angle in the range of 5° to 40° (e.g., 15°).

[0046] like Figure 9 As shown, in the layer formed by high-angle helical winding, the angle α2 between the winding direction of the fiber bundle 80 and the axial direction DAx is greater than the angle α1 of the low-angle helical winding. The angle α2 is, for example, any angle in the range of 65° to 87° (e.g., 80°).

[0047] After the spiral layer forming process, a thermosetting process is performed to heat and cure the ring layer 53 and the spiral layer 58 together. Figure 3 (Step P70). After the heat curing treatment, the pressure on the lining 40 is released (step P80). Through the series of steps described above, tank 10 is completed.

[0048] Figure 10 This is a diagram used to illustrate the 10t tank of the reference example. Figure 10 Is with Figure 2 Comparable diagram. 10t tank and Figure 2 The difference between the can 10 in the illustrated embodiment and the can 10 is the shape of the ring end layer 52t. Since other structures are the same in can 10t and can 10, descriptions of the same structures are appropriately omitted.

[0049] The end layer 52t of the ring hoop of the 10t tank does not protrude radially outward from the main body layer 51 towards the main stem 42, as it extends from the main body layer 51 toward the dome ( Figure 10 The thickness decreases as the first dome top (44) is reached. The outer surface of the ring end layer 52t is curved, forming an inclined surface 53tfa that is tilted relative to the axial direction DAx. Figure 2 as well as Figure 10 In the specified cross-section shown, inclined plane 53tfa is more gently inclined than inclined plane 53fa. That is, for all points along the axial direction DAx in the specified cross-section, the angle between the tangents of inclined planes 53tfa and 53fa and the axial direction DAx is smaller for inclined plane 53tfa than for inclined plane 53fa.

[0050] When the fiber bundle 80 is wound onto the inclined surface 53tfa of the ring end layer 52t by helical winding, the angle β1 between the winding direction FD of the fiber bundle 80 and the tangent of the portion of the ring end layer 52t to which the fiber bundle 80 is wound is much less than 90°. Therefore, when the fiber bundle 80 is pressed towards the ring end layer 52t, the force exerted by the fiber bundle 80 on the ring end layer 52t is dispersed, resulting in a situation where the desired tension cannot be applied. Consequently, the tightness of the connection between the ring end layer 52t and the helical layer 58 decreases, and a gap is generated in the region Rg between the ring end layer 52t and the helical layer 58. This gap can lead to voids and peeling between the ring end layer 52t and the helical layer 58. In cases where voids or peeling occur, reducing the strength of the tank 10t and making it impossible to fill the receiving chamber 25 with high-pressure fuel gas, cracks may occur at the shoulder due to stress (e.g., shear force) generated at the shoulder of the reinforcing layer 50 located at the boundary region between the ring layer 53t and the dome 44, 46.

[0051] Figure 11 This diagram is used to further explain the spiral layer formation process. Figure 11Is with Figure 2 The corresponding diagram. When the fiber bundle 80 is spirally wound on the inclined surface 53fa of the ring end layer 52 in this embodiment, the angle β2 between the winding direction FD of the fiber bundle 80 and the tangent of the portion of the ring end layer 52 where the fiber bundle 80 is wound is greater than... Figure 10 The angle β1 shown can be closer to 90°. That is, by making the end layer 52 of the hoop more radially outward than the main body layer 51 of the hoop, the inclination of the inclined surface 53fa relative to the axial direction DAx can be greater than that of the hoop end layer 52. Figure 10 The shown ring end layer 52t does not protrude radially outward from the ring main layer 51. Therefore, when the fiber bundle 80 is wound around the inclined surface 53fa of the ring end layer 52 by helical winding, the force dispersing the pressure on the fiber bundle 80 towards the ring end layer 52 can be suppressed, thus allowing the desired tension to be applied to the fiber bundle 80. Consequently, since the pressure of the fiber bundle 80 towards the ring end layer 52 corresponding to the desired tension can be increased, the degree of adhesion between the helical layer 58 and the ring layer 53 can be improved, reducing the possibility of gaps forming between the helical layer 58 and the ring layer (especially the ring end layer 52). Therefore, the reduction in the strength of the can 10 can be suppressed.

[0052] Furthermore, according to the above-described embodiments, such as Figure 2 As shown, the inclined surface 53fa and the outer surface 44fa of the dome 44 form an isotensile curved surface. Therefore, since the unevenness of the tension applied to the fiber bundles 80 of the reinforcing layer 50 formed on the inclined surface 53fa and the outer surface 44fa can be reduced, the strength of the tank 10 can be further improved. Furthermore, according to the above embodiment, as... Figures 4-7 As shown, the hoop layer 53 is formed by heat curing a pre-positioned hoop layer 63, which is a cylindrical component formed by winding sheet fiber 60 around a mandrel 70 that is different from the lining 40, into the hoop layer 63. Therefore, the hoop layer 53 can be easily formed by configuring the pre-positioned hoop layer 63.

[0053] B. Other implementation methods:

[0054] B-1. Other implementation methods 1:

[0055] In the above embodiment, the hoop layer 53 is formed by thermosetting the hoop layer 63 formed using sheet fiber 60, but it is not limited to this. For example, the hoop layer 53 can also be formed by hoop-winding fibers impregnated with thermosetting resin around the main body 42 of the lining 40. The winding direction of the fibers is along the circumferential direction of the main body 42. When the hoop layer 53 is formed by hoop-winding fibers, the hoop body layer 51 and the hoop end layer 52 can be formed by changing the number of layers, or by cutting or grinding the fibers to a certain thickness to form the shape of the hoop layer 53.

[0056] This disclosure is not limited to the embodiments described above, and can be implemented in various structures without departing from its spirit. For example, for the technical features of the embodiments corresponding to the technical features in the various methods described in the Summary of the Invention section, appropriate substitutions or combinations can be made to solve some or all of the above-mentioned problems, or to achieve some or all of the above-mentioned effects. In addition, technical features that are not described as essential in this specification can be appropriately deleted.

Claims

1. A method for manufacturing a tank, the tank being used to contain fluid within it, wherein, have: The process of preparing the lining, wherein the lining has a cylindrical main body with a central axis and dome-shaped tops disposed at both ends of the main body; and The process of forming a reinforcing layer, wherein the reinforcing layer is disposed on the lining and comprises fibers. The process of forming the reinforcing layer includes the process of forming a ring layer on the main body and the process of forming a spiral layer throughout the ring layer and the dome. The process of forming the hoop layer includes the steps of forming a hoop body layer and a hoop end layer, wherein the hoop end layer is connected to the hoop body layer and is located at the end along the axial direction of the central axis. The end layer of the ring hoop is shaped to protrude radially outward from the main body layer of the ring hoop, having an outermost vertex located in the radial direction and a slope extending from the vertex toward the outer surface of the dome and following the shape of the outer surface. The bevel is formed by processing the cylindrical component, which is obtained by winding sheet fibers onto a component different from the lining and then pulling out the component different from the lining, in a manner that makes the shape of the hoop layer the same as the shape of the circumference layer.

2. The method for manufacturing a can according to claim 1, wherein, In a cross-section of the can taken with a plane passing through and parallel to the central axis, the distance of the inclined plane is greater than or equal to the width of the fiber bundle used to form the spiral layer.

3. The method for manufacturing a can according to claim 1 or 2, wherein, The distance between the apex in the radial direction and the outer surface of the main body is more than 1.05 times and less than 1.10 times the thickness of the main ring layer.

4. The method for manufacturing a can according to claim 1 or 2, wherein, The inclined plane and the outer surface of the dome form an iso-tension curved surface.

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