JP6790997B2 - How to manufacture high pressure tank - Google Patents

Description

The present invention relates to a method for manufacturing a high pressure tank.

As a high-pressure tank, a high-pressure tank in which a fiber-reinforced resin layer is formed on the outer peripheral surface of a liner which is a base material of the tank is known. Patent Document 1 describes, as a method for forming a fiber-reinforced resin layer, in addition to a filament winding method (hereinafter, also referred to as "FW method") in which a fiber impregnated with a resin is wound around a liner and then cured. , The so-called RTM (Resin Transfer Molding) method is described. When a high-pressure tank is manufactured using the RTM method, a fiber-reinforced resin layer is formed by winding fibers around the outer peripheral surface of a liner to form a fiber layer and then impregnating the fiber layer with a resin.

JP-A-2015-059123

The fiber-reinforced resin layer of the high-pressure tank needs to have a predetermined thickness or more in order to secure the strength. However, in the RTM method, when fibers are wound around a liner to form a fiber layer so as to have a thickness of a predetermined value or more, it is difficult to impregnate the resin over the entire thick fiber layer. Therefore, a technique for improving the impregnation property of the resin into the entire fiber layer has been desired.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following forms.
[Form 1]
A method for manufacturing a high-pressure tank, wherein a fiber member is wound around a liner which is a base material of the high-pressure tank to form a fiber layer on the outer peripheral surface of the liner, and the fiber layer is formed. The fiber is provided with a resin impregnation step of arranging the liner inside a mold for curing the resin and impregnating the fiber layer with the resin, and a resin curing step of curing the resin after the resin impregnation step. The layer forming step includes a hoop layer forming step of forming a single or a plurality of hoop layers by hoop winding and a helical layer forming step of forming a single or a plurality of helical layers by helical winding, and the hoop layer forming step. Then, in each of the single or a plurality of hoop layers, the fiber member is wound so that the ratio of the volume of the fiber member to the volume of the space around which the fiber member is wound is 50% or more and 98% or less. In the helical layer forming step, the fiber member is wound so that the ratio is 50% or more and 98% or less in each of the single or plurality of helical layers, and the single or plurality of hoop layers are rotated. The average value of the ratio in the above is higher than the average value of the ratio in the single or a plurality of helical layers, and the helical layer forming step includes a step of forming the helical layer as the innermost layer of the fiber layer. A method for manufacturing a high-pressure tank, in which in the step of forming the helical layer as the innermost layer, the fiber member is wound so that the ratio is 50% or more and 80% or less.

According to one embodiment of the present invention, a method for manufacturing a high pressure tank is provided. The method for manufacturing the high-pressure tank includes a fiber layer forming step in which a fiber member is wound around a liner which is a base material of the high-pressure tank to form a fiber layer on the outer peripheral surface of the liner; the fiber layer is formed. A liner is arranged inside a mold for curing a resin, and a resin impregnation step of impregnating the fiber layer with the resin; and a resin curing step of curing the resin after the resin impregnation step; The forming step includes a hoop layer forming step of forming a single or a plurality of hoop layers by hoop winding and a helical layer forming step of forming a single or a plurality of helical layers by helical winding; in the hoop layer forming step. In each of the single or plurality of hoop layers, the fiber member is wound so that the ratio of the volume of the fiber member to the volume of the space around which the fiber member is wound is 50% or more and 98% or less. In the helical layer forming step, in each of the single or plural helical layers, the fiber member is wound so that the proportion is 50% or more and 98% or less; in the single or plural hoop layers. The average value of the proportions is higher than the average value of the proportions in the singular or plural helical layers. According to the method for manufacturing a high-pressure tank of this form, in each of the hoop layer and the helical layer, the ratio of the volume of the fiber member to the volume of the space around which the fiber member is wound is 50% or more 98. It is wound so that it is less than%. Therefore, since a gap is formed inside the fiber layer, the resin easily enters the gap in the resin impregnation step. Therefore, the impregnation property of the resin into the entire fiber layer can be improved. Further, since the average value of the ratio in the hoop layer is higher than the average value of the ratio in the helical layer, the hoop layer having a high contribution rate to the strength of the high-pressure tank can be formed more densely than the helical layer. It is possible to suppress a decrease in the strength of the high-pressure tank.

The present invention can also be realized in various forms. For example, it can be realized in the form of a high-pressure tank, a fuel cell system equipped with a high-pressure tank, a method for manufacturing a fuel cell vehicle including the above manufacturing method as a part of a process, and the like.

It is sectional drawing which shows the structure of the high pressure tank manufactured by the manufacturing method of the high pressure tank as one Embodiment of this invention. It is explanatory drawing which shows the structure of the hoop layer schematically. It is explanatory drawing which shows typically the structure of the helical layer. It is a process drawing which shows the manufacturing method of a high pressure tank. It is a process drawing which shows the detailed procedure of the fiber layer formation process. It is sectional drawing for demonstrating the state after the process S115 is executed. It is explanatory drawing which shows an example of the relationship between the thickness of the fiber layer which can be impregnated with resin, and the coverage rate. It is explanatory drawing which shows an example of the relationship between the type of resin and curing time. It is explanatory drawing which shows an example of the impregnation curing cost of resin for each construction method.

A. Embodiment:
A-1. High pressure tank configuration:
FIG. 1 is a cross-sectional view showing a configuration of a high-pressure tank manufactured by the method for manufacturing a high-pressure tank according to an embodiment of the present invention. The high pressure tank 10 is used in a fuel cell system to store hydrogen gas as a fuel gas. The high-pressure tank 10 may be used for storing a high-pressure fluid other than hydrogen gas. FIG. 1 shows a cross section of the high pressure tank 10 including the axis CX. The high-pressure tank 10 includes a liner 20, two bases 90, and a fiber-reinforced resin layer 30.

The liner 20 is a hollow base material and is made of polyethylene in this embodiment. Instead of polyethylene, it may be formed of another resin material such as polyamide or ethylene vinyl alcohol copolymer, or instead of resin, it may be formed of a metal material such as aluminum. The liner 20 includes a cylindrical portion 21 and two dome portions 22. The cylindrical portion 21 has a cylindrical appearance shape. The two dome portions 22 are connected to both ends of the cylindrical portion 21, and each has a dome-shaped appearance shape. The axis of the liner 20 coincides with the axis CX of the high pressure tank 10.

The two caps 90 are attached to the tops of the two dome portions 22, respectively. The base 90 has a substantially tubular appearance shape and is used for attaching pipes and valves.

The fiber reinforced resin layer 30 is formed so as to cover the entire outer surface of the liner 20. The fiber-reinforced resin layer 30 has pressure resistance and has a function of increasing the strength of the liner 20. The fiber reinforced resin layer 30 includes a fiber resin layer 40 and a resin layer 80.

The fiber resin layer 40 has a structure in which the fiber layer 50, which will be described later, is impregnated with a resin and cured. The method for forming the fiber resin layer 40 will be described in detail in the method for manufacturing the high pressure tank 10 described later. The fiber layer 50 has a structure in which carbon fibers are wound in multiple layers and a plurality of layers made of such fibers are laminated. The fiber layer 50 of the present embodiment includes a plurality of hoop layers 60 and a plurality of helical layers 70.

FIG. 2 is an explanatory diagram schematically showing the configuration of the hoop layer 60. The hoop layer 60 covers the outer peripheral surface of the cylindrical portion 21 of the liner 20. The hoop layer 60 is formed by laminating a plurality of layers made of carbon fibers 51 wound by hoop winding. The hoop winding means a winding method in which the carbon fiber 51 is wound around the cylindrical portion 21 with a predetermined winding tension at a winding angle substantially orthogonal to the axis CX, and the winding position is shifted in parallel with the axis CX. In the present embodiment, the hoop layer 60 is formed by winding the carbon fibers 51 while providing a constant gap G1. The gap G1 will be described in detail in the method for manufacturing the high-pressure tank 10 described later.

FIG. 3 is an explanatory diagram schematically showing the configuration of the helical layer 70. The helical layer 70 covers the outer peripheral surface of the cylindrical portion 21 of the liner 20 and the outer peripheral surface of the dome portion 22. The helical layer 70 is formed by laminating a plurality of layers made of carbon fibers 51 wound by helical winding. Helical winding is a winding angle larger than 0 ° and smaller than 90 °, and while spirally winding around the entire liner 20 in the winding direction along the axis CX, the winding direction is folded back at the dome portion 22 and again from 0 °. It means a method of spirally winding around the entire liner 20 at a winding angle smaller than 90 °. In the present embodiment, the helical layer 70 is formed by winding the carbon fibers 51 while providing a constant gap G2. The gap G2 will be described in detail in the method for manufacturing the high pressure tank 10 described later.

The carbon fiber 51 is formed by bundling a large number of single fibers having a diameter of about several μm (micrometer). In this embodiment, polyacrylonitrile (PAN) -based carbon fiber is used as the carbon fiber 51. In addition, instead of the PAN-based carbon fiber, any other arbitrary carbon fiber 51 such as rayon-based carbon fiber and pitch-based carbon fiber may be used.

In the present embodiment, the thickness of the fiber layer 50 in the thickness direction of the high pressure tank 10 is set to 20 mm. In general, in the fiber layer 50, the contribution ratio of the high pressure tank 10 to the strength is higher in the hoop layer 60 than in the helical layer 70.

The resin layer 80 shown in FIG. 1 is made of a thermosetting resin and covers the entire outer surface of the fiber resin layer 40. The resin layer 80 of this embodiment is made of an epoxy resin. In addition, instead of the epoxy resin, it may be composed of any other thermosetting resin such as polyester resin and polyamide resin.

In the present embodiment, the carbon fiber 51 corresponds to the subordinate concept of the fiber member in the means for solving the problem.

A-2. High-pressure tank manufacturing method:
FIG. 4 is a process diagram showing a method for manufacturing the high pressure tank 10. The high pressure tank 10 of this embodiment is manufactured by the RTM method. First, the liner 20 and the carbon fiber 51 are prepared (step S105). Two bases 90 are attached to the liner 20 in advance. After step S105, a fiber layer forming step is executed (step S110).

FIG. 5 is a process diagram showing a detailed procedure of the fiber layer forming process. As described above, the fiber layer 50 of the present embodiment includes a plurality of hoop layers 60 and a plurality of helical layers 70. Therefore, in the fiber layer forming step, a plurality of hoop layers 60 and a plurality of helical layers 70 are formed. The hoop layer 60 and the helical layer 70 are formed by winding the carbon fibers 51 so as to have a predetermined coverage ratio.

The coverage ratio means the ratio of the volume of the carbon fiber 51 to the volume of the space around which the carbon fiber 51 is wound. For example, when the carbon fiber 51 is wound without gaps, the coverage rate is 100%. In the present embodiment, the coverage ratio is calculated from the proportion of the carbon fibers 51 in the cross section including the axis CX and including a plurality of layers in the stacking direction of the carbon fibers 51. As the cross section, the cross section of the cylindrical portion 21 is used instead of the cross section of the dome portion 22 shown in FIG. The reason for this is that the arrangement of the carbon fibers 51 is simpler in the cylindrical portion 21 than in the dome portion 22, so that the coverage ratio can be easily calculated. In such a cross section, assuming that the width of the wound carbon fibers 51 is W and the width between the adjacent carbon fibers 51 (widths of the gaps G1 and G2) is WG, the coverage ratio is, for example, the following formula (1). Can be represented by.
Coverage (%) = 100 x W / (W + WG) ... (1)

The coverage ratio can be adjusted, for example, by changing the width of the gap G1 and the width of the gap G2. The value of the coverage ratio in each hoop layer 60 and each helical layer 70 is preset.

In the fiber layer forming step, the helical layer 70 is first formed by helically winding the carbon fibers 51 so that the coverage is 50% or more and 98% or less (step S205).

As shown in FIG. 3, the helical layer 70 is formed by winding the carbon fiber 51 on the outer peripheral surface of the liner 20 while providing a constant gap G2. In the present embodiment, in the helical layer 70 first formed in the fiber layer forming step, the carbon fiber 51 is wound while providing a gap G1 having the same size as the width of the carbon fiber 51. In other words, the innermost helical layer 70 is formed so that the coverage rate is 50%.

After the step S205 shown in FIG. 5 is executed, the hoop layer 60 is formed by hoop-wrapping the carbon fibers 51 so that the coverage is 50% or more and 98% or less (step S210).

As shown in FIG. 2, the hoop layer 60 is formed by winding the carbon fiber 51 around the outer peripheral surface of the cylindrical portion 21 of the liner 20 while providing a constant gap G1. In the present embodiment, the hoop layer 60 is formed by winding the carbon fibers 51 so that the coverage is 95%.

After the step S210 shown in FIG. 5 is executed, it is determined whether or not a predetermined number of helical layers 70 and hoop layers 60 are formed (step S215). When it is determined that the helical layer 70 and the hoop layer 60 having a predetermined number of layers are not formed (step S215: NO), the process returns to the above-mentioned step S205. Therefore, after that, the helical layer 70 and the hoop layer 60 are further laminated on the helical layer 70 and the hoop layer 60 formed in the previous steps S205 and S210. As a result, the fiber layer 50 having the plurality of helical layers 70 and the plurality of hoop layers 60 is formed. In the present embodiment, each helical layer 70 other than the innermost layer is formed by winding carbon fibers 51 so that the coverage ratio is 90%.

When it is determined in step S215 that a predetermined number of helical layers 70 and hoop layers 60 have been formed (step S215: YES), the fiber layer forming step is completed.

In the fiber layer forming step of the present embodiment, the fiber layer 50 is formed so that the average value of the coverage rate in the hoop layer 60 is higher than the average value of the coverage rate in the helical layer 70. The average value of the coverage ratio in the hoop layer 60 is calculated by dividing the total coverage ratio of each hoop layer 60 by the number of layers of the hoop layer 60. Similarly, the average value of the coverage ratio in the helical layer 70 is calculated by dividing the total coverage ratio of each helical layer 70 by the number of layers of the helical layer 70.

As shown in FIG. 4, after the fiber layer forming step (step S110) is completed, the liner 20 on which the fiber layer 50 is formed is arranged inside the RTM type 300 (step S115).

FIG. 6 is a schematic cross-sectional view for explaining a state after the step S115 is executed. FIG. 6 shows a cross section including the axis CX of the high pressure tank 10 and the liner 20 as in FIG. In FIG. 6, only the cross section of the portion of the RTM type 300 adjacent to the high pressure tank 10 is shown.

The RTM type 300 includes an upper mold and a lower mold (not shown), and a resin injection port 320 is formed. By combining the upper mold and the lower mold, a void cavity 310 is formed inside the RTM type 300. The cavity 310 is designed in a shape and size that can accommodate the liner 20 on which the fiber layer 50 is formed. In this embodiment, the cavity 310 is formed to be slightly larger than the liner 20 on which the fiber layer 50 is formed. More specifically, when the liner 20 on which the fiber layer 50 is formed is arranged in the cavity 310, the entire area between the RTM type 300 and the liner 20 on which the fiber layer 50 is formed is 1 mm. It is formed so that a gap G3 is open.

After step S115 shown in FIG. 4, the temperature of the RTM type 300 is raised and evacuated from a vacuum suction port (not shown) (step S120). The temperature at the time of such temperature rise is set so as to satisfy the curing temperature of the resin used in the subsequent step, for example, about 160 ° C.

After the step S120, the resin is injected into the cavity 310 from the resin injection port 320, and the fiber layer 50 is impregnated with the resin (step S125). More specifically, the resin injected from the resin injection port 320 flows through the gap G3 shown in FIG. 6 so as to cover the entire outer surface of the fiber layer 50. Further, the resin that has passed through the gap G3 is impregnated in the fiber layer 50 by flowing in the thickness direction of the high pressure tank 10 through the gap G1 of the hoop layer 60 and the gap G2 of the helical layer 70.

After step S125, the resin is cured (step S130). The curing time of the resin is set based on the curing time (pot life) of the thermosetting resin used. In this embodiment, the curing time of the resin is set to 5 minutes. In step S130, the resin impregnated in the fiber layer 50 is cured to form the fiber resin layer 40. At the same time, the resin filled in the gap G3 is cured to form the resin layer 80. Therefore, the fiber reinforced resin layer 30 including the fiber resin layer 40 and the resin layer 80 is formed on the outer peripheral surface of the liner 20.

After the step S130, the high-pressure tank 10 is removed from the RTM type 300 by releasing the evacuation of the RTM type 300 and lowering the temperature to separate the upper mold and the lower mold of the RTM type 300 (step S135). As a result, the production of the high pressure tank 10 is completed.

In the present embodiment, the coverage rate corresponds to the subordinate concept of the ratio of the volume of the fiber member to the volume of the space around which the fiber member is wound in the means for solving the problem. Further, step S115 and step S125 are subordinate concepts of the resin impregnation step in the means for solving the problem, step S130 is a subordinate concept of the resin curing step in the means for solving the problem, and step S205 is a subconcept. The process S210 corresponds to a subordinate concept of the helical layer forming step in the means for solving the problem, and the step S210 corresponds to the subordinate concept of the hoop layer forming step in the means for solving the problem. Further, the RTM type 300 corresponds to the subordinate concept of the mold for curing the resin in the means for solving the problem, and the cavity 310 corresponds to the subordinate concept inside the mold in the means for solving the problem.

FIG. 7 is an explanatory diagram showing an example of the relationship between the thickness of the fiber layer that can be impregnated with the resin and the coverage rate. In FIG. 7, the vertical axis represents the thickness (mm) of the fiber layer that can be impregnated with the resin. In the bar graph of FIG. 7, the plain bar on the left side shows the fiber layer of the comparative example, and the hatched bar on the right side shows the fiber layer 50 of the present embodiment.

The fiber layer of the comparative example has a structure in which the coverage of each hoop layer is 100% and the coverage of each helical layer is 100%. In the fiber layer of the comparative example, since the carbon fibers are wound without gaps, the impregnation property of the resin is poor, and the resin is impregnated only about 4 mm. Here, in general, the fiber-reinforced resin layer of the high-pressure tank needs to have a predetermined thickness or more in order to secure the strength. When such a thickness is, for example, 20 mm, when a high-pressure tank is manufactured by the RTM method using the fiber layer of the comparative example, the portion corresponding to the thickness of 16 mm in the fiber-reinforced resin layer is regarded as a resin-unreachable portion that is not impregnated with resin. Occur.

On the other hand, in the fiber layer 50 of the present embodiment, the coverage of each hoop layer 60 is 95%, and the coverage of each helical layer 70 is 90% (the coverage of the innermost helical layer 70). Has a configuration of 50%). Therefore, since the gaps G1 and G2 are formed inside the fiber layer 50, the resin easily enters the gaps G1 and G2, the impregnation property of the resin in the thickness direction of the high pressure tank 10 is improved, and the resin is about 25 mm. Is impregnated up to. Therefore, the fiber-reinforced resin layer 30 having a thickness capable of ensuring the strength of the high-pressure tank 10, for example, a thickness of 20 mm or more described above can be formed.

According to the method for manufacturing the high-pressure tank 10 of the present embodiment described above, the fiber layer 50 is formed so that the coverage of each of the hoop layer 60 and the helical layer 70 is 50% or more and 98% or less. To. Therefore, the fiber layer 50 is formed with a gap G1 of the hoop layer 60 and a gap G2 of the helical layer 70. Therefore, in the step of impregnating the fiber layer 50 with the resin (step S125), the resin easily enters the gaps G1 and G2, and the fiber layer 50 has a coverage rate of 100% as compared with the structure of the fiber layer 50. The impregnation property of the resin to the whole can be improved.

Further, according to the method for manufacturing the high-pressure tank 10 of the present embodiment, the average value of the coverage rate in the hoop layer 60 is higher than the average value of the coverage rate in the helical layer 70. Therefore, since the hoop layer 60 having a high contribution rate to the strength of the high pressure tank 10 is formed denser than the helical layer 70, it is possible to suppress a decrease in the strength of the high pressure tank 10.

Since the fiber layer 50 has a coverage ratio of 50% in the innermost helical layer 70, the fiber layer 50 has a structure in which the gap G2 in the innermost layer is large. As a result, in the resin impregnation step, the fluidity of the resin on the outer surface of the liner 20 can be improved, the impregnation property can be improved, and the generation of unreachable portions of the resin that are not impregnated with the resin can be suppressed. In addition, since the innermost helical layer 70 has a low contribution rate to the strength of the high pressure tank 10, even if the coverage rate is relatively low at 50%, the decrease in strength of the high pressure tank 10 can be suppressed.

The cavity 310 of the RTM type 300 used in the present embodiment is between the RTM type 300 and the liner 20 on which the fiber layer 50 is formed when the liner 20 on which the fiber layer 50 is formed is arranged in the cavity 310. It is formed so as to have a gap G3 of 1 mm over the entire surface. Therefore, the injected resin can flow over the entire outer surface of the fiber layer 50 by passing through the gap G3, and the impregnation property can be improved.

Further, since the high-pressure tank 10 is manufactured using the RTM type 300, it is possible to suppress a decrease in the surface roughness on the outer peripheral surface of the high-pressure tank 10 and improve the dimensional accuracy of the outer diameter of the high-pressure tank 10. Therefore, it is possible to improve the stickability of labels on the outer peripheral surface of the high-pressure tank 10, and improve the mountability of the high-pressure tank 10 on a fuel cell vehicle or the like.

Further, when the high-pressure tank 10 is manufactured by the RTM method, a resin having a short pot life can be used as a material, so that the time required for the step of curing the resin can be significantly shortened. This effect will be described below.

FIG. 8 is an explanatory diagram showing an example of the relationship between the type of resin and the curing time. In FIG. 8, the vertical axis shows the time (minutes) required for curing the resin. In the bar graph of FIG. 8, the plain bar on the left side shows the epoxy resin for the toe prepreg (hereinafter, also referred to as “TPP”) of the comparative example, and the hatched bar on the right side is used in the present embodiment. The epoxy resin for the RTM method is shown. The epoxy resin for TPP is an epoxy resin used in the FW method in which carbon fibers impregnated with the resin are wound around a liner.

The epoxy resin for TPP does not cure while the carbon fibers are wound around the liner, and has a long pot life so that it cures after the carbon fibers have been wound. Therefore, for example, it takes a long time of about 160 minutes to cure the epoxy resin for TPP (252B epoxy resin).

On the other hand, the epoxy resin for the RTM method (manufactured by Nagase ChemteX Corporation) used in the present embodiment has a short pot life (about 5 minutes). This is because the resin is impregnated after the winding of the carbon fiber 51 is completed, so that it is not necessary to consider the time for winding the carbon fiber 51 around the liner 20 as the usable time of the resin.

Further, in the RTM method used in the present embodiment, the cost required for impregnation and curing of the resin can be significantly reduced. This effect will be described below.

FIG. 9 is an explanatory diagram showing an example of resin impregnation curing cost for each construction method. In FIG. 9, the vertical axis shows the cost required for impregnation and curing of the resin. In the bar graph of FIG. 9, the plain bar on the left side shows, as a comparative example, a method of manufacturing a carbon fiber impregnated with a resin in advance as a prepreg, winding the carbon fiber around a liner, and then curing the resin. The hatched bar on the right side indicates the RTM method used in this embodiment.

In the construction method of the comparative example, a step of manufacturing a prepreg is required, and as described above, a resin having a long pot life is used, so that it takes a long time to cure the resin. Therefore, the cost required for impregnation and curing of the resin is high. On the other hand, in the RTM method used in the present embodiment, the step of manufacturing the prepreg can be omitted, and the manufacturing process of the high-pressure tank 10 can be simplified. Further, since the resin having a short pot life may be used as described above, the time required for the step of curing the resin can be shortened. In addition, the structure of the fiber layer 50 as described above can improve the impregnation property of the resin, so that the time required for the step of impregnating the resin can be shortened.

B. Modification example:
B-1. Modification 1:
The structure of the fiber layer 50 in the above embodiment is merely an example and can be changed in various ways. For example, the fiber layer 50 was configured such that the coverage of each hoop layer 60 was 95%, and the coverage of each helical layer 70 other than the innermost layer was 90%, but the hoop layer 60 and The coverage of the helical layer 70 including the innermost layer may be any value of 50% or more and 98% or less, respectively. From the viewpoint of suppressing the decrease in strength of the high-pressure tank 10, the coverage of each hoop layer 60 is preferably 90% or more, and the coverage of each helical layer 70 other than the innermost layer is 80% or more. Is preferable. Further, the coverage of the innermost helical layer 70 is preferably 80% or less, more preferably 60% or less, from the viewpoint of suppressing a decrease in the impregnation property of the resin on the outer surface of the liner 20. Further, the coverage rate of each hoop layer 60 among the plurality of hoop layers 60 may be different, and the coverage rate of each helical layer 70 among the plurality of helical layers 70 is a different value. You may. Further, in the above embodiment, the fiber layer 50 has a plurality of hoop layers 60 and a plurality of helical layers 70, but the number of layers of the hoop layer 60 and the helical layer 70 may be singular. .. Further, the outermost layer of the fiber layer 50 is not limited to the hoop layer 60 and may be a helical layer 70. Further, other hoop layers and helical layers having a coverage rate of less than 50% may be provided within a range that does not reduce the strength of the high-pressure tank 10, and the coverage rate is within a range that does not reduce the impregnation property of the resin. It may have more than 98% other hoop and helical layers. Even with the above configuration, the same effect as that of the high-pressure tank 10 of the embodiment is obtained on the premise that the average value of the coverage of the hoop layer 60 is higher than the average value of the coverage of the helical layer 70.

B-2. Modification 2:
In the above embodiment, the coverage rate has been calculated based on the above formula (1), but the present invention is not limited thereto. For example, it may be calculated from the volume of the carbon fiber 51 wound around the unit volume in the state before winding and the unit volume, and the volume of the space around which the carbon fiber 51 is wound by any other method. The ratio of the carbon fiber 51 to the carbon fiber 51 may be calculated.

B-3. Modification 3:
In the above embodiment, the hoop layer 60 is formed by winding a carbon fiber 51 formed by bundling a large number of single fibers around the cylindrical portion 21 of the liner 20, but instead of this, a predetermined coverage ratio is provided. The hoop layer 60 may be formed by winding a sheet-like member made of carbon fiber having the hoop layer 60. Further, although the fiber layer 50 is formed of the carbon fiber 51, the fiber layer 50 may be formed of any other fiber member such as glass fiber instead of the carbon fiber 51. Even with such a configuration, the same effect as that of the high-pressure tank 10 of the embodiment can be obtained.

B-4. Modification 4:
The high-pressure tank 10 in the above embodiment includes the fiber resin layer 40 and the resin layer 80 as the fiber reinforced resin layer 30, but the resin layer 80 may be omitted. Further, the thickness of the resin layer 80 is not limited to 1 mm, and may be any value within, for example, 2 mm. Further, a protective layer made of a glass fiber reinforced resin may be further provided on the outer surface of the fiber reinforced resin layer 30. Even with such a configuration, the same effect as that of the high-pressure tank 10 of the embodiment can be obtained.

The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit of the present invention. For example, the embodiments corresponding to the technical features in each of the embodiments described in the column of the outline of the invention, the technical features in the modified examples are used to solve some or all of the above-mentioned problems, or the above-mentioned above. It is possible to replace or combine them as appropriate to achieve some or all of the effects. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 ... High-pressure tank 20 ... Liner 21 ... Cylindrical part 22 ... Dome part 30 ... Fiber reinforced resin layer 40 ... Fiber resin layer 50 ... Fiber layer 51 ... Carbon fiber 60 ... Hoop layer 70 ... Helical layer 80 ... Resin layer 90 ... Base 300 ... RTM type 310 ... Cavity 320 ... Resin injection port CX ... Axis line G1 ... Gap G2 ... Gap G3 ... Gap

Claims (1)

It is a method of manufacturing a high-pressure tank.
A fiber layer forming step of winding a fiber member around a liner which is a base material of the high-pressure tank to form a fiber layer on the outer peripheral surface of the liner.
A resin impregnation step of arranging the liner on which the fiber layer is formed inside a mold for curing a resin and impregnating the fiber layer with resin,
After the resin impregnation step, a resin curing step of curing the resin and
With
The fiber layer forming step includes a hoop layer forming step of forming a single or a plurality of hoop layers by hoop winding, and a helical layer forming step of forming a single or a plurality of helical layers by helical winding.
In the hoop layer forming step, in each of the single or a plurality of hoop layers, the ratio of the volume of the fiber member to the volume of the space around which the fiber member is wound is 50% or more and 98% or less. It is wound so that it becomes
In the helical layer forming step, in each of the single or plurality of helical layers, the fiber member is wound so that the ratio is 50% or more and 98% or less.
The average value of the ratio in one or more of the hoop layer, rather higher than the average value of the ratio of the one or more helical layers,
The helical layer forming step includes a step of forming the helical layer as the innermost layer of the fiber layer.
In the step of forming the helical layer as the innermost layer, the fiber member is wound so that the ratio is 50% or more and 80% or less.
Manufacturing method of high pressure tank.

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