JP2018161821A - Method for manufacturing high pressure tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disclose a technique for reducing the formation of recesses on a surface of a high pressure tank.SOLUTION: A method for manufacturing a high pressure tank includes the steps of: (A) forming a first not-yet-cured thermosetting resin layer on a liner; (B) forming a second not-yet-cured thermosetting resin layer on a surface of the first not-yet-cured thermosetting resin layer; and (C) after the step (B), heating from the outside of the second not-yet-cured thermosetting resin layer so that a second gelation time being a time until a second thermosetting resin gelates is longer than a first gelation time being a time until a first thermosetting resin gelates. When each of the first thermosetting resin and the second thermosetting resin is heated in the same temperature-increasing speed, the second thermosetting resin has a second standard gelation time being a time until the second thermosetting resin gelates longer than a first standard gelation time being a time until the first thermosetting resin gelates.SELECTED DRAWING: Figure 5

Description

  The technology disclosed in the present specification relates to a high-pressure tank.

  As a high-pressure tank filled with a fluid such as hydrogen gas at a high pressure, a high-pressure tank including a liner and an outer shell layer formed on the surface of the liner is known. The structure provided with a carbon fiber strong resin layer and a glass fiber resin layer as an outer shell layer is proposed (for example, refer patent document 1).

JP 2010-90938 A

  In the production of a high-pressure tank, when a layer containing an uncured resin is formed on a liner, gas may be involved in the resin. Moreover, gas is generated by a curing reaction when the resin is cured, and may be included in the resin. Due to the gas contained in these resins, a convex portion may be formed on the surface of the high-pressure tank when the resin is cured.

  In this specification, the technique which suppresses formation of the convex part in the surface of a high-pressure tank is disclosed.

  The technology disclosed in the present specification has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one form of the technique disclosed in this specification, a method for manufacturing a high-pressure tank is provided. The method for producing the high-pressure tank includes (A) a step of forming a first thermosetting resin uncured layer including a first uncured first thermosetting resin and fibers on a liner; A step of forming a second thermosetting resin uncured layer containing an uncured second thermosetting resin on the surface of the first thermosetting resin uncured layer; and (C) after the step (B), From the outside of the second thermosetting resin uncured layer, the second gelation time, which is the time until the second thermosetting resin gels, is the time until the first thermosetting resin gels. Heating the first thermosetting resin and the second thermosetting resin so as to be longer than the first gelation time, which is a time, and the second thermosetting resin comprises: When each of the first thermosetting resin and the second thermosetting resin is heated at the same rate of temperature rise, 2 is a time until gelation of the thermosetting resin and the second normal gelling time is longer than the first standard gel time is the time until gelation of the first thermosetting resin.

  In the manufacturing method of the high pressure tank of this form, in the step (C), the time until the second thermosetting resin gels (second gelation time) is the time until the first thermosetting resin gels. Since the heating is performed so as to be longer than the time (first gelation time), the second thermosetting resin is slower to gel than the first thermosetting resin. Therefore, since the first thermosetting resin gels in the state where the second thermosetting resin has fluidity, the second thermosetting resin is almost completely released from the inclusion gas of the first thermosetting resin uncured layer. The curable resin gels. Therefore, formation of the convex part on the surface of the high-pressure tank can be suppressed. Even if the encapsulated gas remains in the gelled first thermosetting resin and the surface of the gelled first thermosetting resin (contact surface with the second thermosetting resin) is not smooth, 2 Since the thermosetting resin has fluidity, the surface of the second thermosetting resin layer becomes smooth. Therefore, formation of the convex part on the surface of the high-pressure tank can be suppressed.

  The technology disclosed in this specification can be realized in various modes. For example, the present invention can be realized in the form of a high-pressure tank, a fuel cell system including the high-pressure tank, a moving body equipped with the fuel cell system, and the like.

It is sectional drawing which shows schematic structure of a high pressure tank. It is a table | surface which shows a composition of 1st thermosetting resin. It is a table | surface which shows a composition of 2nd thermosetting resin. It is a figure which shows the temperature-viscosity characteristic of 1st thermosetting resin and 2nd thermosetting resin. It is process drawing which shows the manufacturing method of a high pressure tank. It is a figure which shows the temperature increase delay time with respect to the 2nd thermosetting resin uncured layer of the 1st thermosetting resin uncured layer. It is explanatory drawing which shows a temperature measurement location. It is a figure which shows the temperature profile in process S18 of the manufacturing method of a high pressure tank. It is a figure which shows notionally the time-dependent change of the viscosity of 1st thermosetting resin and 2nd thermosetting resin in process S18 of the manufacturing method of a high pressure tank.

A. Embodiment:
A1. High pressure tank configuration:
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a high-pressure tank as an embodiment of the disclosed technique. In the present embodiment, the high-pressure tank 100 is for filling with compressed hydrogen, for example. The high-pressure tank 100 is mounted on a fuel cell vehicle in order to supply hydrogen to the fuel cell, for example. The high-pressure tank 100 is not limited to the fuel cell vehicle, and may be mounted on other vehicles such as an electric vehicle and a hybrid vehicle, or may be mounted on other moving bodies such as a ship, an airplane, and a robot. Moreover, you may be provided in stationary installations, such as a house and a building.

  The high-pressure tank 100 is a hollow container having a cylindrical portion 102 having a substantially cylindrical shape and substantially hemispherical dome portions 104 provided integrally at both ends thereof. In FIG. 1, the boundary between the cylindrical portion 102 and the dome portion 104 is indicated by a broken line. The high-pressure tank 100 includes a liner 10, a reinforcing layer 20, a protective layer 25, a base 30, and a base 40. Hereinafter, the liner 10 to which the base 30 and the base 40 are attached is also referred to as a “tank body”.

  The liner 10 is made of nylon resin and has a property (so-called gas barrier property) that blocks hydrogen and the like filled in the internal space from leaking outside. The liner 10 may be manufactured using another synthetic resin having a gas barrier property such as a polyethylene-based resin, or a metal such as stainless steel.

  The reinforcing layer 20 is formed so as to cover the outer surface of the tank body. Specifically, the reinforcing layer 20 is formed so as to cover the entire outer surface of the liner 10 and part of the caps 30 and 40. The reinforcing layer 20 is made of carbon fiber reinforced resin (CFRP), which is a composite material of the first thermosetting resin and carbon fiber, and has pressure resistance. In this embodiment, an epoxy resin is used as the first thermosetting resin.

  The protective layer 25 is formed on the reinforcing layer 20. The protective layer 25 is made of a glass fiber reinforced resin (GFRP), which is a composite material of the second thermosetting resin and glass fiber, and has higher impact resistance than the reinforcing layer 20. In this embodiment, an epoxy resin is used as the second thermosetting resin. However, when each of the first thermosetting resin and the second thermosetting resin is heated at the same rate of temperature increase, the second standard gelation is the time until gelation of the second thermosetting resin. The types and amounts of the curing accelerator and the curing agent are adjusted so that the time is longer than the first standard gelation time, which is the time until the first thermosetting resin is gelled. The composition of the first thermosetting resin and the second thermosetting resin will be described later.

  The bases 30 and 40 are respectively attached to the two open ends of the liner 10. The base 30 functions as an opening of the high-pressure tank 100 and also functions as an attachment portion for attaching piping and valves to the tank body. The caps 30 and 40 also function as attachment portions for attaching the tank body to a filament winding apparatus (hereinafter referred to as FW apparatus) when the reinforcing layer 20 and the protective layer 25 are formed.

  FIG. 2 is a table showing the composition of the first thermosetting resin. In this specification, a composition means the ratio of a component and its quantity. The first thermosetting resin consists of 40-50 wt% bisphenol A epoxy resin as the main agent, 1-10 wt% liquid rubber as the modifying agent, 30-40 wt% tetrahydrophthalic anhydride as the curing agent, and capsules as the curing accelerator. 1.0 to 2.0 wt% of type amines, 5 to 15 wt% of core-shell rubber as a reinforcing agent (toughness improvement), and 0.1 to 1.0 wt% of a thermoplastic polymer as an antifoaming agent. In addition, the ratio of each component is determined so that the ratio of each component is within the range of FIG. 2 and the total is 100 wt%.

  FIG. 3 is a table showing the composition of the second thermosetting resin. The second thermosetting resin is 55 to 65 wt% of bisphenol A type epoxy resin as a main agent, 35 to 45 wt% of tetrahydrophthalic anhydride as a curing agent, and 0.1 to 1.0 wt of capsule type amines as a curing accelerator. %, And 0.1 to 0.2 wt% of silicone as an antifoaming agent. In addition, the ratio of each component is determined so that the ratio of each component is within the range of FIG. 3 and the total is 100 wt%. The types and amounts of components other than the main agent including the curing agent and the curing accelerator contained in the first thermosetting resin and the second thermosetting resin are not limited to this embodiment, and can be changed as appropriate.

  FIG. 4 is a diagram showing temperature-viscosity characteristics of the first thermosetting resin and the second thermosetting resin. FIG. 4 shows a semilogarithmic graph with the viscosity axis as a logarithmic scale. The second gelation temperature T2 that is the gelation temperature of the second thermosetting resin is higher than the first gelation temperature T1 that is the gelation temperature of the first thermosetting resin. The gelation temperature refers to the temperature at which the viscosity suddenly changes from a fluid solution state to a gel state. Gel transition temperature, gel dissolution temperature, phase transition temperature, sol-gel phase transition temperature, gel It is synonymous with a term called a conversion point. Gelation means that the fluidity is lost, and in this embodiment, it means a state where the viscosity is increased so that the viscosity cannot be measured. The temperature-viscosity characteristics shown in FIG. 4 are obtained by using a E-type viscometer (for example, RE550H manufactured by Toki Sangyo Co., Ltd.) to heat a high temperature resin in a sol state at a low shear rate at a rate of 7 degrees / minute It can obtain | require from the viscosity curve obtained, making it. Also, using a rheometer (for example, a stress control type rheometer using a cone plate, Physica MCR series, manufactured by Anton Paar), a viscosity curve obtained while changing the temperature of a high-temperature resin in a sol state at a low shear rate, It can obtain | require from the viscoelastic curve obtained by measuring the temperature change of dynamic viscoelasticity. The temperature-viscosity characteristics are not limited to the measurement method of the present embodiment, and can be obtained by various known measurement methods. The viscosity measurement of the first thermosetting resin and the second thermosetting resin may be performed by the same method, and the gelation temperature may be determined based on the same standard. Since the second gelation temperature T2 which is the gelation temperature of the second thermosetting resin is higher than the first gelation temperature T1 which is the gelation temperature of the first thermosetting resin, the second thermosetting resin and the first thermosetting resin When each of the two thermosetting resins is heated at the same rate of temperature increase, the second standard gelation time, which is the time until gelation of the second thermosetting resin, is the same as that of the first thermosetting resin. It is longer than the first standard gelation time, which is the time until gelation. In this specification, the gelation time when the first thermosetting resin and the second thermosetting resin are heated at the “same temperature increase rate” is referred to as “standard” gelation time.

A2. Manufacturing method of high-pressure tank:
FIG. 5 is a process diagram showing a method for manufacturing the high-pressure tank 100. In the present embodiment, the high-pressure tank 100 (FIG. 1) is manufactured by a filament winding method (FW method). In step S12, a liner 10 and resin-impregnated fibers (resin-impregnated carbon fiber and resin-impregnated glass fiber) are prepared. Specifically, the tank body in which the base 30 and the base 40 are mounted on the liner 10 is set as a mandrel in an FW device (not shown), and the resin-impregnated carbon fiber and the resin-impregnated glass fiber wound around the bobbin are respectively FW Set to a predetermined position on the device. In this embodiment, the resin impregnated in the carbon fiber is a first thermosetting resin, and the resin impregnated in the glass fiber is a second thermosetting resin.

  In step S14, the resin-impregnated carbon fiber is wound around the outer surface of the tank body (including the outer surface of the liner 10). Specifically, the FW device is started, the tank body rotates, and the resin-impregnated carbon fiber is fed out from the bobbin, and the resin-impregnated carbon fiber is wound around the outer surface of the tank body. At this time, hoop winding, helical winding, etc. are combined suitably and a resin impregnation carbon fiber is wound. Hereinafter, the one in which the resin-impregnated carbon fiber is wound around the outer surface of the tank body is also referred to as “carbon fiber wound tank body”. When the resin-impregnated carbon fiber is wound with a predetermined number of turns and the resin-impregnated carbon fiber layer is formed, the resin-impregnated carbon fiber is cut, and the winding end (end) of the resin-impregnated carbon fiber is the end of the resin-impregnated glass fiber. Crimping (thermocompression bonding, etc.) is applied to the winding start end (start end). The resin-impregnated carbon fiber layer includes an uncured first thermosetting resin (before curing) and carbon fibers. The resin-impregnated carbon fiber layer in the present embodiment is also referred to as “first thermosetting resin uncured layer”.

  In step S16, resin-impregnated glass fibers are wound on the resin-impregnated carbon fiber layer of the carbon fiber-wound tank body formed in step S14, as in step S14, to form a resin-impregnated glass fiber layer. . The resin-impregnated glass fiber layer includes an uncured second thermosetting resin (before curing) and glass fibers. The resin-impregnated glass fiber layer in the present embodiment is also referred to as “second thermosetting resin uncured layer”.

  In step S18, through steps S14 and S16, the fiber-wound tank body in which the resin-impregnated carbon fiber layer and the resin-impregnated glass fiber layer are formed on the outer periphery of the liner 10 is placed in a heating furnace. Then, the first thermosetting resin of the resin-impregnated carbon fiber layer and the second thermosetting resin of the resin-impregnated glass fiber layer reach a curing temperature (for example, about 160 ° C.) while the fiber-wound tank body is rotated. To be heated. In the present embodiment, the second gelation time t2 which is the time until the second thermosetting resin gels is the first gelation time t1 which is the time until the first thermosetting resin gels. It is heated so that it becomes longer. Specifically, after heating for 50 minutes at a set temperature of 180 ° C. in the heating furnace, it is heated for 70 minutes at a set temperature of 160 ° C. The setting of the heating environment in step S18 will be described later.

  In the column of step S <b> 18 in FIG. 5, temporal changes in temperature and viscosity of the first thermosetting resin and the second thermosetting resin are conceptually illustrated. Since the second thermosetting resin uncured layer is formed outside the first thermosetting resin uncured layer, the fiber wound tank body is placed in a heating furnace, and the fiber wound tank body is placed. When heated from the outside, the temperature of the second thermosetting resin rises faster than that of the first thermosetting resin. Further, the second gelation time t2, which is the time for the second thermosetting resin of the second thermosetting resin uncured layer to gel, is the first thermosetting resin of the first thermosetting resin uncured layer. It is longer than the first gelation time t1, which is the time for gelation. That is, after the first thermosetting resin contained in the first thermosetting resin uncured layer as the inner layer is gelled, the second thermosetting resin contained in the second thermosetting resin uncured layer as the outer layer. Gels.

  When the first thermosetting resin and the second thermosetting resin are cured in step S18, the reinforcing layer 20 and the protective layer 25 are formed. Thereafter, the set temperature of the heating furnace is lowered and the high-pressure tank 100 is taken out.

  FIG. 6 is a diagram showing a temperature rise delay time of the first thermosetting resin uncured layer with respect to the second thermosetting resin uncured layer. The time until the second thermosetting resin uncured layer reaches 150 ° C. on the horizontal axis, and the time for the second thermosetting resin uncured layer to reach 150 ° C. on the vertical axis. It shows the delay time for the resin uncured layer (the time until the first thermosetting resin uncured layer reaches 150 ° C.—the time until the second thermosetting resin uncured layer reaches 150 ° C.). . FIG. 6 shows a case where a fiber-wound tank body is prepared using an epoxy resin (FIGS. 2 and 3) having the same composition as that of the present embodiment as the first thermosetting resin and the second thermosetting resin, and the heating environment is changed. The experiment of changing and heating was performed, and the results of measuring the temperature rising rate of each thermosetting resin uncured layer are shown (indicated by white circles in FIG. 6). The heating furnace is configured to be able to change the temperature increase rate of the furnace atmosphere temperature. For example, when setting the furnace temperature to 180 ° C., it is set to 180 ° C. (1 step), 140 ° C. → 180 ° C. (2 steps), 140 ° C. → 160 ° C. → 180 ° C. (3 steps), There is a setting for increasing the temperature in a stepless manner (linear, curved) with respect to time. The heating furnace includes a fan, and is configured to be able to adjust the wind speed of the fan and the angle of the wind with respect to the fiber wound tank body. In this experiment, the temperature setting speed of the first thermosetting resin and the second thermosetting resin are changed by changing the temperature setting of the heating furnace and the wind speed of the fan.

  FIG. 7 is an explanatory diagram showing temperature measurement locations. In the above experiment, as the measurement point Tm1 of the first thermosetting resin uncured layer, two points are measured at the dome portion and two points at the trunk portion. Similarly, as the measurement point Tm2 of the second thermosetting resin uncured layer, two points are measured at the dome portion and two points at the trunk portion. The resin temperature can be measured using a known resin temperature measuring device such as a thermocouple type or an infrared type. In FIG. 6, the average of each measurement point is illustrated.

  From this experimental result, the higher the rate of temperature rise of the second thermosetting resin uncured layer (the smaller the value on the horizontal axis in FIG. 6), the more the first thermosetting resin uncured layer (inner layer) and the second heat It can be seen that the temperature difference from the curable resin uncured layer (outer layer) increases.

  In the present embodiment, the second thermosetting resin has a lower content (wt%) of the curing accelerator than the first thermosetting resin (FIGS. 2 and 3), and the second thermosetting resin is The gelation temperature is higher than that of the first thermosetting resin (FIG. 4). When the first thermosetting resin and the second thermosetting resin are heated to have the same rate of temperature increase, the gelation time (second standard gelation time) of the second thermosetting resin is 1 It is longer than the gel time (first standard gel time) of the thermosetting resin. However, when heated from the outside of the fiber wound tank body, as shown in FIG. 6, the outer layer (second thermosetting resin uncured layer) and the inner layer (first thermosetting resin uncured layer) ) And there is a difference in the rate of temperature rise, so if the difference in temperature rise rate between the outer layer and the inner layer is large, the outer layer will gel before the inner layer, even if the gelation temperature of the outer layer is set high. there's a possibility that. Therefore, each heat is set so that the gelation time of the second thermosetting resin (second gelation time t2) in step S18 is longer than the gelation time of the first thermosetting resin (first gelation time t1). The temperature rising rate of the curable resin was adjusted.

A method for determining the heating environment in step S18 of the present embodiment will be described.
First, the composition of the first thermosetting resin and the second thermosetting resin is determined. In this embodiment, the amount of the curing accelerator is determined so that the gelation temperature of the second thermosetting resin is higher by about 30 ° C. than the gelation temperature of the first thermosetting resin. Here, the curing accelerator is reduced with respect to the content of the first thermosetting resin.

  Second, the temperature increase rate-gelation temperature characteristics of the first thermosetting resin and the second thermosetting resin, respectively, are obtained. Specifically, the first thermosetting resin is melted by heating alone at a constant temperature, temperature-viscosity characteristics are acquired, and gelation temperature is acquired. The same experiment is performed at a plurality of heating temperatures, and the temperature increase rate-gelation temperature characteristic is acquired. For the second thermosetting resin, the same experiment is performed for a plurality of heating temperatures identical to those of the first thermosetting resin, and the temperature increase rate-gelation temperature characteristic is acquired. This is because the gelation temperature varies depending on the heating rate.

Third, using the temperature rise delay time of the first thermosetting resin uncured layer of FIG. 6 with respect to the second thermosetting resin uncured layer and the above-described temperature rise rate-gelation temperature characteristics, The combination of the heating rate satisfying the relational expression (Equation 1) is found. That is, the combination of the temperature increase rate which makes the gelation time of 2nd thermosetting resin longer than the gelation time of 1st thermosetting resin is attached. In the present embodiment, the temperature increase rate indicated by an asterisk in FIG. 6 is determined.
(Gelation temperature of second thermosetting resin−initial tank temperature) / temperature increase rate of second thermosetting resin> (gelation temperature of first thermosetting resin−initial tank temperature) / first thermosetting Temperature rise rate of resin ... (Formula 1)
Here, the gelation temperature of the second thermosetting resin is the gelation temperature at the rate of temperature increase of the second thermosetting resin of the denominator, and the gelation temperature of the first thermosetting resin is the first of the denominator. It is the gelation temperature at the rate of temperature increase of the thermosetting resin. The initial tank temperature is a tank temperature when the fiber-wound tank main body is put into a heating furnace, and 25 ° C. (normal temperature) is used in this embodiment.

  Fourth, the steps S12 to S16 shown in FIG. 5 are performed to create a fiber-wound tank body, the heating environment of the heating furnace is changed, and the combination of the temperature rising speeds in the above third The heating method is determined. Specifically, the heating rate of the first thermosetting resin uncured layer and the second thermosetting resin uncured layer is changed by changing the heating rate of the atmospheric temperature in the heating furnace and the wind speed of the fan included in the heating furnace. Observe. The temperature measurement points are the same as the measurement points shown in FIG. The faster the rate of temperature rise in the furnace temperature, the faster the rate of temperature rise of the second thermosetting resin uncured layer, and the faster the fan speed, the greater the rate of temperature rise of the second thermosetting resin uncured layer. fast. If the wind speed of the fan is excessively high, problems such as cracks on the surface of the high-pressure tank may occur.

In the present embodiment, the heating environment is adjusted by the first to fourth so that the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin. The rate of temperature increase of the first thermosetting resin and the second thermosetting resin varies depending on, for example, the following factors.
(1) Thicknesses of the first thermosetting resin uncured layer and the second thermosetting resin uncured layer (2) Composition of the resin (components and ratio of the amount)
(3) Temperature increase rate of the atmospheric temperature in the heating furnace (4) Wind speed (air volume) of the fan provided in the heating furnace
(5) Fan angle of the furnace (wind angle relative to the tank)
(6) Self-heating of thermosetting resin In the present embodiment, the factor (1) is determined in advance according to the required performance of the high-pressure tank. The factor (5) is determined in advance when the heating furnace is set. Therefore, (2) to (4) were adjusted.

A3. Effects of the embodiment:
FIG. 8 is a diagram showing a temperature profile in step S18 of the method for manufacturing a high-pressure tank of the present embodiment. In FIG. 8, the temperature of the first thermosetting resin is indicated by a broken line, the temperature of the second thermosetting resin is indicated by a solid line, and the equipment temperature is indicated by a one-dot chain line. As the temperature of each thermosetting resin, among the measurement points Tm1 and Tm2 shown in FIG. 7, two measurement points for the body part are used, and the average is shown. As equipment temperature, the result of having measured the atmospheric temperature near the fiber wound tank in a heating furnace using the same measuring device as the measuring device of thermosetting resin temperature is illustrated.

  The rate of temperature increase of the first thermosetting resin and the second thermosetting resin changes with the passage of time. Therefore, the temperature range in which the curing reaction of the first thermosetting resin proceeds and the release (movement) of the inclusion gas of the first thermosetting resin is large (Ta (° C.) to Tb (° C.) in FIG. 8). Note the heating rate in). Here, the temperature range in which the release (movement) of the encapsulated gas of the first thermosetting resin is large is a temperature range in which the viscosity of the first thermosetting resin decreases. In the present embodiment, the temperature range is 80 ° C. to 120 ° C. Yes (Fig. 4). In this embodiment, the curing reaction proceeds at 80 ° C. or higher. When the temperature increase rate of the first thermosetting resin at temperatures Ta (° C.) to Tb (° C.) is R1, and the temperature increase rate of the second thermosetting resin is R2, the relationship of the above (formula 1) is satisfied. Yes. Thus, the temperature increase rate in the temperature range in which the curing reaction of the first thermosetting resin proceeds and the release (movement) of the inclusion gas of the first thermosetting resin is large is the above (Formula 1). When the heating environment is adjusted so as to satisfy the relationship, the gelation time of the second thermosetting resin becomes slower than the gelation time of the first thermosetting resin.

  FIG. 9 is a diagram conceptually showing a change over time in the viscosities of the first thermosetting resin and the second thermosetting resin in step S18 of the method for manufacturing a high-pressure tank of the present embodiment. According to the manufacturing method of the high-pressure tank in the present embodiment, the gelation time of the second thermosetting resin (t2 in FIG. 9) is longer than the gelation time of the first thermosetting resin (t1 in FIG. 9).

  As described above, in the present embodiment, when each of the first thermosetting resin and the second thermosetting resin is heated at the same rate of temperature increase, the second thermosetting resin is gelled. The second standard gelation time, which is the time for the above, is longer than the first standard gelation time, which is the time until the first thermosetting resin is gelled. And when heating a fiber wound tank main body with a heating furnace, it heats so that the gelling time of 2nd thermosetting resin may become longer than the gelling time of 1st thermosetting resin. Therefore, since the first thermosetting resin gels in the state where the second thermosetting resin has fluidity, the second thermosetting resin is almost completely released from the inclusion gas of the first thermosetting resin uncured layer. The curable resin gels. Even if the encapsulated gas remains in the gelled first thermosetting resin and the surface of the gelled first thermosetting resin (contact surface with the second thermosetting resin) is not smooth, 2 Since the thermosetting resin has fluidity, the surface of the second thermosetting resin layer becomes smooth. As a result, the formation of convex portions on the surface of the high-pressure tank can be suppressed.

B. Variation:
(1) The fluid stored in the high-pressure tank 100 is not limited to the compressed hydrogen described above, and may be a high-pressure fluid such as compressed nitrogen.

(2) As fibers contained in the reinforcing layer 20 and the protective layer 25, various fibers capable of constituting a fiber reinforced resin, such as carbon fibers, glass fibers, aramid fibers, dynea fibers, zylon fibers, and boron fibers, can be used. . The reinforcing layer 20 preferably has pressure resistance, and the protective layer 25 is preferably selected from fibers so that the impact resistance is higher than that of the reinforcing layer 20. When carbon fibers are used as the fibers of the reinforcing layer 20 and glass fibers or aramid fibers are used as the fibers of the protective layer 25, the reinforcing layer 20 having a higher pressure resistance and the protective layer 25 having a higher impact resistance than the reinforcing layer 20 are used. Is preferable.

(3) The protective layer 25 may be formed using only the second thermosetting resin. In that case, it is preferable to select a resin having desired impact resistance higher than that of the reinforcing layer 20 as the protective layer 25. In the case where the protective layer 25 is formed of only a resin, the protective layer 25 can be formed by spraying the resin and heating it by a known method such as spray coating. For example, in the above embodiment, when the protective layer 25 is formed of only the second thermosetting resin, the carbon fiber impregnated with the first thermosetting resin is wound around the liner 10 and then sprayed or the like. After the second thermosetting resin is sprayed by the well-known method, the reinforcing layer 20 and the protective layer 25 are formed by heating and curing the first thermosetting resin and the second thermosetting resin. be able to.

(4) In the said embodiment, although the same kind resin (epoxy resin) from which gelation temperature differs was used as 1st thermosetting resin and 2nd thermosetting resin, 1st thermosetting resin and 2nd thermosetting resin were used. The thermosetting resin may be a different type of thermosetting resin. For example, the first thermosetting resin may be an unsaturated polyester resin and the second thermosetting resin may be an epoxy resin. Moreover, you may reverse this. Even when different types of resins are used in this way, when each of the first thermosetting resin and the second thermosetting resin is heated at the same rate of temperature increase, the second thermosetting resin is gelled. The second standard gelation time that is the time until the first thermosetting resin is adjusted to be longer than the first standard gelation time that is the time until the first thermosetting resin is gelled. The difference in gelation time (difference in gelation temperature) can be set as appropriate. And in the heating process by a heating furnace, by heating so that the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin, the convex portions on the surface of the high-pressure tank are formed. Formation can be suppressed.

(5) The heating method (set temperature, maintenance time) by the heating furnace of the high-pressure tank manufacturing method is not limited to the above embodiment. Moreover, the determination method of a heating environment is not limited to the said embodiment. However, as in the above-described embodiment, the target value of the temperature increase rate of each thermosetting resin (for example, the temperature increase rate determined in the third method of determining the heating environment of the embodiment) is determined, The heating environment is such that each temperature increase rate in a temperature range where the curing reaction of the thermosetting resin proceeds and in which the gas contained in the first thermosetting resin is released (moved) is close to the target value. Is adjusted, it can be heated relatively easily such that the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin.

(6) The manufacturing method of the high-pressure tank 100 is not limited to the above embodiment. The heating temperature and the heating time can be appropriately changed according to the resin used, the tank shape, and the like. For example, it can be manufactured by a sheet winding method in which a sheet-like fiber reinforced resin is attached, RTM (Resin Transfer Molding) in which a resin is impregnated after attaching a sheet-like fiber.

  The present disclosure technique 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 disclosure. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Liner 20 ... Reinforcement layer 25 ... Protection layer 30 ... Base 40 ... Base 100 ... High pressure tank 102 ... Cylindrical part 104 ... Dome part T1 ... 1st gelation temperature T2 ... 2nd gelation temperature Tm1 ... Measurement point Tm2 ... Measurement Point t1 ... first gel time t2 ... second gel time

Claims (1)

A method for manufacturing a high-pressure tank, comprising:
(A) forming a first thermosetting resin uncured layer on the liner, which includes an uncured first thermosetting resin and fibers;
(B) forming a second thermosetting resin uncured layer containing an uncured second thermosetting resin on the surface of the first thermosetting resin uncured layer;
(C) After the step (B), from the outside of the second thermosetting resin uncured layer, the second gelation time, which is the time until the second thermosetting resin gels, Heating the first thermosetting resin and the second thermosetting resin by heating to be longer than the first gelation time, which is the time until the thermosetting resin is gelled,
With
The second thermosetting resin gels the second thermosetting resin when each of the first thermosetting resin and the second thermosetting resin is heated at the same rate of temperature increase. The method for producing a high-pressure tank, wherein the second standard gelation time, which is the time until the first thermosetting resin, is longer than the first standard gelation time, which is the time until the first thermosetting resin is gelled.

Images