Tank manufacturing method

Abstract

To provide a technique for sufficiently impregnating a tank member with resin in which fibers are wound around a hollow member in two different ways.SOLUTION: A tank manufacturing method includes an arrangement step of arranging a tank member including a hollow member and a fiber layer in a mold, and an injection step. The fiber layer includes a first fiber layer formed in a first region of an outer surface of the hollow member, and a second fiber layer formed in a second region different from the first region of the outer surface of the hollow member. In the first fiber layer, a first fiber is wrapped around the first region in a manner in which the first fiber is woven into the second fiber, and in the second fiber layer, the first fiber is wrapped around the second region in a manner in which the first fiber is not woven into the second fiber. An injection step includes a first step of maintaining a pressure between an inner surface of the mold and an outer surface of the tank member at a predetermined pressure to impregnate the fiber layer with a resin, and a second step of maintaining the pressure higher than a predetermined pressure to impregnate the fiber layer with resin.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present specification discloses a tank manufacturing method for manufacturing a tank. [Background technology]

[0002] Patent Document 1 discloses a pressure vessel constructed by winding reinforcing fibers around a vessel body. The pressure vessel comprises a first reinforcing part in which reinforcing fibers are wound around the outer surface of the vessel body in a staggered weaving manner, and a second reinforcing part in which reinforcing fibers are wound around the outer surface of the vessel body in a Helmet-like manner. In the Helmet-like manner, the reinforcing fibers are not woven. The pressure vessel is impregnated with a thermosetting resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-26817 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, reinforcing fibers are wound around a container body in two different ways. This specification provides a technique for sufficiently impregnating a tank member in which fibers are wound around a hollow member in two different ways with resin. [Means for solving the problem]

[0005] The tank manufacturing method disclosed in the present specification includes an arrangement step of arranging a tank member including a hollow member and a fiber layer formed on an outer surface of the hollow member in a mold, and an injection step of injecting a resin to be impregnated into the fiber layer between an inner surface of the mold and the outer surface of the tank member after the arrangement step, the fiber layer including a first fiber layer formed in a first region of the outer surface of the hollow member, and a second fiber layer formed in a second region of the outer surface of the hollow member that is different from the first region, and in the first fiber layer, a first fiber extending in a first direction is interposed between a second fiber extending in a second direction intersecting the first direction. the first fiber and the second fiber are wound around the first region in a manner in which the first fiber is woven into the second fiber, and in the second fiber layer, the first fiber overlaps the second fiber, and the first fiber and the second fiber are wound around the second region in a manner in which the first fiber is not woven into the second fiber, and the injection process includes a first process of impregnating the fiber layer with the resin by maintaining a pressure between the inner surface of the mold and the outer surface of the tank member at a predetermined pressure, and a second process of impregnating the fiber layer with the resin after the first process by maintaining the pressure at a pressure higher than the predetermined pressure.

[0006] Due to constraints of the manufacturing process, the time for impregnating the resin is limited. For example, the pressure for injecting the resin is increased to increase the speed at which the resin is impregnated. However, if the pressure for injecting the resin is excessively increased, the gap between the first fiber and the second fiber becomes excessively narrow. In particular, the first fiber layer having a mode in which the first fiber is woven into the second fiber has a higher rate of narrowing of the gap between the first fiber and the second fiber than the second fiber layer having a mode in which the first fiber is not woven into the second fiber. If the gap between the first fiber and the second fiber becomes excessively narrow, the resin may not sufficiently impregnate the fiber layer. On the other hand, if the pressure remains low, the time for impregnating the resin becomes excessively long. In particular, the first fiber layer having the first fiber woven into the second fiber tends to have a longer flow path for the resin to be impregnated than the second fiber layer having the first fiber not woven into the second fiber. If the pressure remains low, there may not be enough time for the resin to fully impregnate the fiber layer.

[0007] According to the above configuration, in the first step of maintaining a relatively low predetermined pressure, the fiber layer is impregnated with resin while suppressing narrowing of the gap between the first fiber and the second fiber. Then, in the second step of maintaining a relatively high pressure, the fiber layer is impregnated with resin in a portion that has not yet been impregnated with resin. The portion is, for example, a lower portion of the first fiber layer (i.e., a portion close to the hollow member). By maintaining a pressure higher than the predetermined pressure, it is possible to promote impregnation of the portion with resin within a time limit. Both the first fiber layer and the second fiber layer can be sufficiently impregnated with resin.

[0008] Details and further improvements of the technology disclosed in this specification are described in the following "Forms for Carrying Out the Invention". [Brief description of the drawings]

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0010] (Configuration of tank manufacturing equipment 2; Figure 1) The tank manufacturing apparatus 2 is an apparatus for manufacturing a high-pressure tank for a fuel cell vehicle by impregnating a tank member 10 with resin. The tank member 10 is an intermediate product of a high-pressure tank. The tank member 10 includes a hollow member 18 and first to third fiber layers 12 to 16. The first to third fiber layers 12 to 16 are formed by winding fiber around the outer surface of the hollow member 18. The configuration of the tank member 10 will be described later. The fiber is, for example, carbon fiber.

[0011] The tank manufacturing device 2 includes a mold 26, a hardener tank 30, a pump 32, a base tank 40, a pump 42, and a mixer 50. The mold 26 includes an upper mold 20 and a lower mold 24. The upper mold 20 and the lower mold 24 overlap each other to form a space that conforms to the outer shape of the tank member 10. A pressure sensor 22 for measuring the pressure inside the mold 26 is provided on the inner surface of the upper mold 20. The pressure sensor 22 may be provided on the inner surface of the lower mold 24, or a plurality of pressure sensors 22 may be provided on at least one of the inner surfaces of the upper mold 20 and the lower mold 24.

[0012] The hardener tank 30 stores the hardener. The pump 32 pumps the hardener in the hardener tank 30 to the mixer 50. The pump 32 is installed on a flow path between the hardener tank 30 and the mixer 50.

[0013] The base agent tank 40 stores the base agent to be injected into the mold 26 in the injection process described below. The base agent is, for example, an epoxy resin. The base agent is mixed with a hardener and hardens through a chemical reaction between the two. The pump 42 pumps the base agent in the base agent tank 40 to the mixer 50. The pump 42 is installed on the path between the base agent tank 40 and the mixer 50.

[0014] The mixer 50 mixes the hardener in the hardener tank 30 with the base agent in the base agent tank 40. The mixer 50 includes a pump (not shown) that pressure-feeds the mixed material (i.e., a mixture of the base agent and the hardener) to the mold 26. In a modified example, the mixer 50 does not include a pump, and the mixture may be pressure-feed to the mold 26 by the pumps 32 and 42.

[0015] (Configuration of tank member 10; Figs. 2 to 4) The tank member 10 has a cylindrical, elongated outer shape. Both ends in the longitudinal direction of the tank member 10 (i.e., the hollow member 18 (not shown in FIG. 2)) are tapered nozzles. The first fiber layer 12 is formed on one of the ends, and the third fiber layer 16 is formed on the other of the ends. The second fiber layer 14 is formed in a region (e.g., a cylindrical region) of the hollow member 18 between the ends where the first fiber layer 12 and the third fiber layer 16 are formed.

[0016] In the first fiber layer 12, the first fibers 12a extending in a direction D1 are braided with the second fibers 12b extending in a direction D2 (hereinafter, referred to as a "braiding mode"), and the first fibers 12a and the second fibers 12b are wound around one end in the longitudinal direction of the hollow member 18. The direction D2 intersects with the direction D1, and the direction D2 has a predetermined angle α with respect to the direction D1. As shown in FIG. 3, the first fibers 12a and the second fibers 12b are alternately arranged above and below.

[0017] The third fibrous layer 16 is similar to the first fibrous layer 12, except that the first fibers 12a and the second fibers 12b are wrapped around the other longitudinal end of the hollow member 18.

[0018] In the second fiber layer 14, the first fibers 14a extending in the direction D1 overlap the second fibers 14b extending in the direction D2, and the first fibers 14a and the second fibers 14b are wound around the hollow member 18 in a region (e.g., a cylindrical region) between the first fiber layer 12 and the third fiber layer 16 in a manner in which the first fibers 14a are not woven with the second fibers 14b (hereinafter, referred to as a "Helcaliform"). As shown in FIG. 4, the first fibers 14a overlap the second fibers 14b.

[0019] (Tank manufacturing method; Figure 1) A description will be given of a tank manufacturing method for manufacturing a high-pressure tank by controlling the tank manufacturing apparatus 2 in Fig. 1. The tank manufacturing method includes a placement step and a pouring step.

[0020] In the placement process, the tank member 10 is placed in the mold 26, and mold clamping is performed to press the upper mold 20 against the lower mold 24. After that, degassing is performed to make the space inside the mold 26 (i.e., the space between the inner surface of the mold 26 and the outer surface of the tank member 10) close to a vacuum. Note that an apparatus for performing degassing is not shown in each drawing.

[0021] The injection process is performed after the placement process. In the injection process, the hardener in the hardener tank 30 and the base agent in the base agent tank 40 are pumped into the mixer 50. Then, the mixed material, i.e., the mixture of the base agent and the hardener, is pumped into the mold 26. The mixture flows between the inner surface of the mold 26 and the outer surface of the tank member 10. As the mixture hardens, it impregnates the fiber layers 12-16 of the tank member 10. The injection process is stopped when a predetermined amount of the mixture has been injected.

[0022] Although not shown in the drawings, after the mixture has hardened, the tank member 10 is removed from the mold 26. The fiber layers 12-16 of the removed tank member 10 are impregnated with the hardened mixture. By the tank manufacturing method described above, the high-pressure tank is completed.

[0023] (Injection process; Figure 5) In the injection step of this embodiment, the pressure inside the mold 26 is adjusted. The pressure is adjusted, for example, by the output of the pump of the mixer 50. Graph G1 in Fig. 5 shows the progress of the pressure inside the hollow member 18 in this embodiment, and graph G2 shows the progress of the pressure inside the mold 26 in this embodiment. In the graphs G1 and G2, the horizontal axis indicates time, and the vertical axis indicates pressure.

[0024] As the injection of the mixture begins, the pressure in the hollow member 18 and the pressure in the mold 26 increase. When the pressure in the mold 26 reaches a predetermined pressure P1 at timing t1, the tank manufacturing apparatus 2 adjusts the output of the pump of the mixer 50 so as to maintain the pressure in the mold 26 (i.e., the output value of the pressure sensor 22) at pressure P1. Between timing t1 and timing t2, the pressure in the mold 26 is maintained at pressure P1.

[0025] When the time t2 is reached, the tank manufacturing apparatus 2 increases the output of the pump of the mixer 50. This causes the pressure in the hollow member 18 and the pressure in the mold 26 to rise again. When the pressure in the mold 26 reaches a predetermined pressure P2 at the time t3, the tank manufacturing apparatus 2 adjusts the output of the pump of the mixer 50 so as to maintain the pressure in the mold 26 at pressure P2. Pressure P2 is higher than pressure P1. Between the time t3 and the time t4, the pressure in the mold 26 is maintained at pressure P2.

[0026] When the time t4 is reached, the tank manufacturing apparatus 2 stops the pump of the mixer 50. This stops the injection process. After the time t4, the hardening of the mixture progresses, and the pressure in the hollow member 18 and the pressure in the mold 26 decrease.

[0027] (Effects of this embodiment) Graphs G3 and G4 show a conventional injection process without adjusting the pressure inside the mold 26. Graph G3 shows the progress of the pressure inside the hollow member 18 in the conventional case, and graph G4 shows the progress of the pressure inside the mold 26 in the conventional case.

[0028] Due to restrictions such as manufacturing process constraints, there are limitations on the time for impregnating the mixture. In particular, the time for impregnating the mixture is restricted by the curing start time of the mixture. As shown in graph G3, conventionally, after the pressure in mold 26 rises to pressure P3, the pressure in mold 26 is not adjusted. Conventionally, the pressure in mold 26 levels off near pressure P3. For example, if pressure P3 is too low, the time for impregnating the mixture becomes longer, and there is a possibility that impregnation will not be completed within the time limit. In particular, a fiber layer (e.g., 12) having a braiding pattern tends to have a longer flow path for the mixture to impregnate compared to the fiber layer 14 having a helical pattern. Therefore, if pressure P3 is too low, there is a possibility that impregnation of the fiber layer having a braiding pattern will not be completed within the time limit. Note that the gap between the first fiber (e.g., 12a) and the second fiber (e.g., 12b) (hereinafter referred to as the "fiber gap") tends to be wider in the braiding pattern than in the helical pattern. Therefore, in the braiding pattern and the helical pattern, if the flow path of the mixture is the same, the braiding pattern is more likely to be impregnated than the helical pattern.

[0029] Also, in order to increase the speed at which the mixture is impregnated, pressure P3 may be adjusted higher. However, if pressure P3 is too high, the fiber gap becomes excessively narrow. In particular, a fiber layer having a braiding pattern has a higher rate of narrowing of the fiber gap compared to the fiber layer 14 having a helical pattern. If pressure P3 is too high, although the mixture impregnates the upper side of the fiber layer, there is a possibility that the mixture will not reach the lower side of the fiber layer. Depending on pressure P3, not only the fiber layer having a braiding pattern but also the fiber layer 14 having a helical pattern may not have the mixture reach the lower side (i.e., the portion close to the hollow member 18) of the fiber layer 14 (see Fig. 5).

[0030] In the injection process of this embodiment, between timing t1 and timing t2, the pressure in the mold 26 is maintained at a relatively low pressure P1. Thereby, while suppressing the narrowing of the fiber gaps, the mixture is impregnated into the fiber layers 12 to 16. Subsequently, between timing t3 and timing t4, the pressure in the mold 26 is maintained at a relatively high pressure P2. Thereby, the mixture is impregnated into the portions of the fiber layers 12 to 16 where the mixture has not yet been impregnated (for example, the lower portion of the first fiber layer 12). By maintaining the high pressure P2, the impregnation of the mixture into the relevant portion can be promoted within the time limit. The fiber layers 12 and 16 having the braiding mode and the fiber layer 14 having the helical mode can be sufficiently impregnated with the mixture.

[0031] Also, between timing t3 and timing t4, since the pressure in the mold 26 is maintained at a relatively high pressure P2, the voids generated on the surface of the mixture of the fiber layers 12 to 16 are crushed. The deterioration of the appearance quality of the tank member 10, which is the finished product, can be suppressed.

[0032] (Corresponding relationship) The mold 26 and the mixture are, respectively, examples of the "mold" and the "resin". The hollow member 18 and the tank member 10 are, respectively, examples of the "hollow member" and the "tank member". The fiber layers 12 to 16 are an example of the "fiber layer". The regions at both ends of the tank member 10, the fiber layers 12 and 16 are, respectively, examples of the "first region" and the "first fiber layer". The middle region of the tank member 10, the second fiber layer 14 are, respectively, examples of the "second region" and the "second fiber layer". The directions D1 and D2 are, respectively, examples of the "first direction" and the "second direction". The first fiber 12a and the second fiber 12b are, respectively, examples of the "first fiber" and the "second fiber". The pressure P1 in FIG. 5 is an example of the "predetermined pressure". The injection process from timing t1 to t2 and the injection process from timing t3 to t4 are, respectively, examples of the "first process" and the "second process".

[0033] Hereinafter, points to note regarding the techniques shown in the embodiments will be described: The external shape of the hollow member 18 (and the tank member 10) is not limited to a cylindrical shape, and may be, for example, a polygonal prism shape (for example, a square prism shape).

[0034] For example, a fiber layer having a Helical pattern may be formed in the regions at both ends of the hollow member 18. In this modification, the regions at both ends of the hollow member 18 are an example of a "second region."

[0035] For example, a fiber layer having a braided configuration may be formed in the cylindrical region of the hollow member 18. In this modification, the cylindrical region of the hollow member 18 is an example of the "first region."

[0036] The "resin" is not limited to a mixture, and may be, for example, a base material that does not include a hardener. In this case, the base material may be hardened by heating.

[0037] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0038] 2:Tank manufacturing equipment 10: Tank parts 12: First fiber layer 12a: First fiber 12b: Second fiber 14: Second fiber layer 14a: First fiber 14b: Second fiber 16: Third fiber layer 18: Hollow member 20: Upper mold 22: Pressure sensor 24: Lower mold 26: Mold 30: Hardener tank 32: Pump 40: Main agent tank 42: Pump 50: Mixer D1, D2: Direction G1, G2, G3, G4: Graph P1, P2, P3: Pressure t1, t2, t3, t4: Timing α: Angle

Claims

[Claim 1] a placement step of placing a tank member including a hollow member and a fiber layer formed on an outer surface of the hollow member in a mold; an injection step of injecting, by a pump, a resin to be impregnated into the fiber layer between an inner surface of the mold and an outer surface of the tank member after the placement step; Equipped with the fiber layer includes a first fiber layer formed in a first region of the outer surface of the hollow member, and a second fiber layer formed in a second region of the outer surface of the hollow member, the second region being different from the first region; In the first fiber layer, the first fibers extending in a first direction are woven with second fibers extending in a second direction intersecting the first direction, and the first fibers and the second fibers are wound around the first region; In the second fiber layer, the first fiber overlaps the second fiber, and the first fiber and the second fiber are wound around the second region in a manner that the first fiber is not woven into the second fiber; The injection step includes: a first step of impregnating the fiber layer with the resin by adjusting the output of the pump so as to maintain a predetermined pressure between the inner surface of the mold and the outer surface of the tank member; a second step of impregnating the fiber layer with the resin by adjusting the output of the pump so as to maintain the pressure higher than the predetermined pressure after the first step; A method for manufacturing a tank, comprising:

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