JP6776972B2 - How to make a high pressure tank - Google Patents

Description

The techniques disclosed herein relate to high pressure tanks.

As a high-pressure tank filled with a fluid such as hydrogen gas at a high pressure, a liner and a high-pressure tank provided with an outer shell layer formed on the surface of the liner are known. A configuration including a carbon fiber strong resin layer and a glass fiber resin layer as an outer shell layer has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-90938

In the manufacture of high-pressure tanks, when a layer containing an uncured resin is formed on a liner, gas may be involved in the resin. In addition, gas may be generated by the curing reaction when the resin is cured and may be contained 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.

This specification discloses a technique for suppressing the formation of convex portions on the surface of a high-pressure tank.

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

(1) According to a form of technology disclosed herein, a method of manufacturing a high pressure tank is provided. The method for manufacturing this high-pressure tank includes (A) a step of forming a first thermosetting resin uncured layer containing an uncured first thermosetting resin and fibers on a liner, and (B) the above. 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), The second gelling time, which is the time from the outside of the uncured layer of the second thermosetting resin to the gelation of the second thermosetting resin, is the time until the first thermosetting resin gels. The second thermosetting resin comprises a step of curing the first thermosetting resin and the second thermosetting resin by heating so as to be longer than the first gelation time, which is the time. When each of the first thermosetting resin and the second thermosetting resin is heated at the same heating rate, the second standard is the time until gelation of the second thermosetting resin. The gelation time is longer than the first standard gelation time, which is the time until gelation of the first thermosetting resin.

In the method for manufacturing a high-pressure tank of this form, in the step (C), the time until the second thermosetting resin gels (second gelation time) is until the first thermosetting resin gels. Since the heating is performed so as to be longer than the time (first gelation time), the gelation of the second thermosetting resin is slower than that of the first thermosetting resin. Therefore, in a state where the second thermosetting resin has fluidity, the first thermosetting resin gels, so that the gas contained in the uncured layer of the first thermosetting resin is almost completely released, and then the second heat is generated. The curable resin gels. Therefore, the formation of the convex portion on the surface of the high-pressure tank can be suppressed. Even if the contained 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, the first 2 Since the thermosetting resin has fluidity, the surface of the second thermosetting resin layer becomes smooth. Therefore, the formation of the convex portion on the surface of the high-pressure tank can be suppressed.

The techniques disclosed in the present specification can be realized in various aspects. For example, it can be realized in the form of a high-pressure tank, a fuel cell system including a high-pressure tank, a moving body equipped with the fuel cell system, or the like.

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

A. Embodiment:
A1. High pressure tank configuration:
FIG. 1 is a cross-sectional view showing a schematic configuration of a high-pressure tank as an embodiment of the disclosed technology. In the present embodiment, the high pressure tank 100 is for filling, for example, compressed hydrogen. The high-pressure tank 100 is mounted on a fuel cell vehicle, for example, to supply hydrogen to the fuel cell. The high-pressure tank 100 is not limited to a fuel cell vehicle, and may be mounted on other vehicles such as electric vehicles and hybrid vehicles, or may be mounted on other moving bodies such as ships, airplanes, and robots. Further, it may be provided in a stationary facility such as a house or a building.

The high-pressure tank 100 is a hollow container having a cylindrical portion 102 having a substantially cylindrical shape and a substantially hemispherical dome portion 104 integrally provided 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 of blocking hydrogen and the like filled in the internal space from leaking to the outside (so-called gas barrier property). The liner 10 may be made of another synthetic resin having a gas barrier property such as a polyethylene 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 a part of the bases 30 and 40. The reinforcing layer 20 is made of carbon fiber reinforced resin (CFRP: Carbon Fiber Reinforced Plastics), 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 glass fiber reinforced plastic (GFRP: Glass Fiber Reinforced Plastics), 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 heating rate, the second standard gelation is the time required for the second thermosetting resin to gel. The types and amounts of the curing accelerator and the curing agent are adjusted so that the time is longer than the first standard gelling time, which is the time until gelation of the first thermosetting resin. The composition of the first thermosetting resin and the second thermosetting resin will be described later.

The bases 30 and 40 are attached to the two open ends of the liner 10, respectively. The base 30 functions as an opening of the high-pressure tank 100 and also functions as an attachment portion for attaching a pipe or a valve to the tank body. Further, the bases 30 and 40 also function as attachment portions for attaching the tank body to the filament winding device (hereinafter, FW device) when forming the reinforcing layer 20 and the protective layer 25.

FIG. 2 is a table showing the composition of the first thermosetting resin. As used herein, the term "composition" means a component and a ratio thereof. The first thermosetting resin contains 40 to 50 wt% of bisphenol A type epoxy resin as the main agent, 1 to 10 wt% of liquid rubber as the modifier, 30 to 40 wt% of tetrahydrophthalic anhydride as the curing agent, and capsules as the curing accelerator. It contains 1.0 to 2.0 wt% of type amines, 5 to 15 wt% of core-shell rubber as a reinforcing agent (improved toughness), and 0.1 to 1.0 wt% of a thermoplastic polymer as a defoaming agent. 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 contains 55 to 65 wt% of bisphenol A type epoxy resin as the main agent, 35 to 45 wt% of tetrahydrophthalic anhydride as the curing agent, and 0.1 to 1.0 wt% of capsule type amines as the curing accelerator. %, Contains 0.1 to 0.2 wt% of silicone as an antifoaming agent. 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 type and amount of the 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 semi-logarithmic graph with the axis of viscosity as a logarithmic scale. The second gelling temperature T2, which is the gelling temperature of the second thermosetting resin, is higher than the first gelling temperature T1 which is the gelling temperature of the first thermosetting resin. The gelling temperature refers to the temperature at which the viscosity changes rapidly from a fluid solution state to a gel state, and the gel transition temperature, gel dissolution temperature, phase transition temperature, sol-gel phase transition temperature, and gel. It is synonymous with the term called chemical point. Gelation means that the fluidity is lost, and means that the viscosity is so high that the viscosity cannot be measured in the present embodiment. The temperature-viscosity characteristic shown in FIG. 4 is that a high-temperature resin in a sol state is heated at a low shear rate of 7 degrees / minute using an E-type viscometer (for example, RE550H manufactured by Toki Sangyo Co., Ltd.). It can be obtained from the viscosity curve obtained while allowing the mixture. In addition, a viscosity curve obtained by changing the temperature of a high-temperature resin in a sol state at a low shear rate using a rheometer (for example, a stress-controlled rheometer using a cone plate, Physica MCR series, manufactured by Antonio Par). It can be obtained from the viscoelasticity curve obtained by measuring the temperature change of dynamic viscoelasticity. The temperature-viscosity property is not limited to the measuring method of the present embodiment, and can be obtained by various known measuring methods. The viscosity of the first thermosetting resin and the second thermosetting resin may be measured by the same method, and the gelation temperature may be determined based on the same criteria. Since the second gelling temperature T2, which is the gelling temperature of the second thermosetting resin, is higher than the first gelling temperature T1 which is the gelling temperature of the first thermosetting resin, the first thermosetting resin and the first When each of the two thermosetting resins is heated at the same temperature rise rate, the second standard gelation time, which is the time until gelation of the second thermosetting resin, is that of the first thermosetting resin. It is longer than the first standard gelation time, which is the time to gelation. In the present specification, the gelation time when the first thermosetting resin and the second thermosetting resin are heated at the “same temperature rise rate” is referred to as a “standard” gelation time.

A2. High-pressure tank manufacturing method:
FIG. 5 is a process diagram showing a method for manufacturing the high pressure tank 100. In this embodiment, the high pressure tank 100 (FIG. 1) is manufactured by the filament winding method (FW method). In step S12, the liner 10 and the resin-impregnated fiber (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 attached to the liner 10 is set in the FW device (not shown) as a mandrel, and the resin-impregnated carbon fiber and the resin-impregnated glass fiber wound around the bobbin are FW, respectively. It is set in a predetermined position on the device. In the present embodiment, the resin impregnated in the carbon fibers is the first thermosetting resin, and the resin impregnated in the glass fibers is the 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, the resin-impregnated carbon fibers are fed out from the bobbin, and the resin-impregnated carbon fibers are wound around the outer surface of the tank body. At this time, the resin-impregnated carbon fiber is wound by appropriately combining hoop winding, helical winding, and the like. Hereinafter, a tank body in which resin-impregnated carbon fiber is wound around the outer surface of the tank body is also referred to as a “carbon fiber-wrapped tank body”. When the resin-impregnated carbon fiber is wound with a predetermined number of turns to form the resin-impregnated carbon fiber layer, the resin-impregnated carbon fiber is cut, and the winding end (end) of the resin-impregnated carbon fiber is the resin-impregnated glass fiber. It is crimped (heat crimped, etc.) to the winding start end (start end). The resin-impregnated carbon fiber layer contains an uncured (before curing) first thermosetting resin and carbon fibers. The resin-impregnated carbon fiber layer in the present embodiment is also referred to as a "first thermosetting resin uncured layer".

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

In step S18, the fiber-wrapped 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 put into the heating furnace through steps S14 and S16. Then, while the fiber-wrapped tank body is rotated, the first thermosetting resin of the resin-impregnated carbon fiber layer and the second thermosetting resin of the resin-impregnated glass fiber layer reach the curing temperature (for example, about 160 ° C.). To be heated. In the present embodiment, the second gelling time t2, which is the time until the second thermosetting resin gels, is the first gelling time t1 which is the time until the first thermosetting resin gels. It is heated to be longer than. Specifically, after heating at a set temperature of 180 ° C. for 50 minutes in a heating furnace, heating is performed at a set temperature of 160 ° C. for 70 minutes. The setting of the heating environment in step S18 will be described later.

In the column of step S18 of FIG. 5, the time course of the temperature and viscosity of the first thermosetting resin and the second thermosetting resin is conceptually illustrated. Since the second thermosetting resin uncured layer is formed outside the first thermosetting resin uncured layer, the fiber-wrapped tank body is put into a heating furnace, and the fiber-wrapped tank body is put into the heating furnace. When heated from the outside, the temperature of the second thermosetting resin rises faster than that of the first thermosetting resin. Further, the second gelling time t2, which is the time for the second thermosetting resin of the second thermosetting resin uncured layer to gel, is such that the first thermosetting resin of the first thermosetting resin uncured layer is used. 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 which is the inner layer gels, the second thermosetting resin contained in the second thermosetting resin uncured layer which is the outer layer Gells.

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. After that, 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 horizontal axis is the time required for the second thermosetting resin uncured layer to reach 150 ° C., and the vertical axis is the time required for the first thermosetting resin uncured layer to reach 150 ° C. The delay time with respect to the resin uncured layer (time until the first thermosetting resin uncured layer reaches 150 ° C.-time until the second thermosetting resin uncured layer reaches 150 ° C) is shown. .. In FIG. 6, a fiber-wrapped 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 set. An experiment of changing and heating is performed, and the result of measuring the heating rate of each thermosetting resin uncured layer is shown (indicated by white circles in FIG. 6). The heating furnace is configured so that the rate of temperature rise of the ambient temperature inside the furnace can be changed. For example, when setting the furnace temperature to 180 ° C, set to 180 ° C (1 step), set to 140 ° C → 180 ° C (2 steps), set to 140 ° C → 160 ° C → 180 ° C (3 steps), It has a setting for raising the temperature steplessly (straight line, curved line) with respect to time. Further, the heating furnace is provided with a fan, and is configured so that the wind speed of the fan and the angle of the wind with respect to the fiber-wrapped tank body can be adjusted. In this experiment, the temperature setting of the heating furnace and the wind speed of the fan are changed to change the heating rate of the first thermosetting resin and the second thermosetting resin.

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

From the results of this experiment, the faster the temperature rise rate of the second thermosetting resin uncured layer (the value on the horizontal axis in FIG. 6 is smaller), the more the first thermosetting resin uncured layer (inner layer) and the second heat. It can be seen that the temperature difference from the uncured layer (outer layer) of the curable resin becomes large.

In the present embodiment, the second thermosetting resin has a smaller 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 so as to have the same heating rate, the gelation time (second standard gelation time) of the second thermosetting resin is the second. 1 It is longer than the gelation time of the thermosetting resin (first standard gelation time). However, when heated from the outside of the fiber-wrapped tank body, as shown in FIG. 6, the outer layer (second thermosetting resin uncured layer) and the inner layer (first thermosetting resin uncured layer) ), Since there is a difference in the heating rate between the outer layer and the inner layer, if the difference in the heating rate between the outer layer and the inner layer is large, the outer layer gels before the inner layer even if the gelling temperature of the outer layer is designed to be 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 rate of temperature rise of the curable resin was adjusted.

The method of 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 the present embodiment, the amount of the curing accelerator is determined so that the gelling temperature of the second thermosetting resin is about 30 ° C. higher than the gelling temperature of the first thermosetting resin. Here, the amount of the curing accelerator is reduced with respect to the content of the first thermosetting resin.

Secondly, the temperature rise rate-gelling temperature characteristics of the first thermosetting resin and the second thermosetting resin, respectively, are acquired. Specifically, the first thermosetting resin is melted by heating it alone at a constant temperature to acquire the temperature-viscosity property and the gelation temperature. Perform the same experiment at multiple heating temperatures to obtain the heating rate-gelling temperature characteristics. For the second thermosetting resin, the same experiment is performed for a plurality of heating temperatures that are the same as those for the first thermosetting resin, and the temperature rise rate-gelling temperature characteristics are acquired. This is because the gelation temperature differs depending on the rate of temperature rise.

Thirdly, 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-mentioned temperature rising rate-gelling temperature characteristic, the following Find a combination of heating rates that satisfies the relational expression (Equation 1) of. That is, the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin. In the present embodiment, the temperature rising rate indicated by a star is determined in FIG.
(Gelification temperature of the second thermosetting resin-initial tank temperature) / Temperature rise rate of the second thermosetting resin> (Gelification temperature of the first thermosetting resin-initial tank temperature) / First thermosetting Resin temperature rise rate ... (Equation 1)
Here, the gelling temperature of the second thermosetting resin is the gelling temperature at the rate of temperature rise of the second thermosetting resin in the denominator, and the gelling temperature of the first thermosetting resin is the first in the denominator. It is the gelling temperature at the heating rate of the thermosetting resin. The initial tank temperature is the tank temperature when the fiber-wrapped tank body is placed in the 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 prepare the fiber-wrapped tank main body, the heating environment of the heating furnace is changed, and the combination of the heating rates given in the third step is obtained. Determine the heating method so that Specifically, the temperature rise rate of the atmospheric temperature in the heating furnace and the air speed of the fan provided in the heating furnace are changed to raise the temperature of the first thermosetting resin uncured layer and the second thermosetting resin uncured layer. Observe. The temperature measurement point is the same as the measurement point shown in FIG. The faster the temperature rise rate of the ambient temperature in the heating furnace, the faster the temperature rise rate of the second thermosetting resin uncured layer, and the faster the wind speed of the fan, the faster the temperature rise rate 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, so this is taken into consideration.

In the present embodiment, the heating environment is adjusted according to the first to fourth steps 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 rise of the first thermosetting resin and the second thermosetting resin varies depending on, for example, the following factors.
(1) Thickness of 1st Thermosetting Resin Uncured Layer and 2nd Thermosetting Resin Uncured Layer (2) Resin Composition (Components and Ratio of Their Amounts)
(3) Increasing rate of atmospheric temperature in the heating furnace (4) Wind speed (air volume) of the fan provided in the heating furnace
(5) Fan angle of the heating furnace (wind angle with respect to the tank)
(6) Self-heat generation of thermosetting resin In this embodiment, the factor (1) is predetermined according to the required performance of the high-pressure tank. The factor (5) is predetermined at the time of setting the heating furnace. Therefore, (2) to (4) were adjusted.

A3. Effect of 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 shown by a broken line, the temperature of the second thermosetting resin is shown by a solid line, and the equipment temperature is shown by a dashed line. As the temperature of each thermosetting resin, out of the measurement points Tm1 and Tm2 shown in FIG. 7, two measurement points of the body portion are used, and the average thereof is shown in the figure. As the equipment temperature, the result of measuring the ambient temperature in the vicinity of the fiber-wrapped tank in the heating furnace using the same measuring device as the thermosetting resin temperature measuring device is shown.

The rate of temperature rise 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 contained gas of the first thermosetting resin is large (Ta (° C.) to Tb (° C.) in FIG. 8). ) Pay attention to the rate of temperature rise. Here, the temperature range in which the contained gas of the first thermosetting resin is largely released (moved) is the temperature range in which the viscosity of the first thermosetting resin decreases, and in the present embodiment, it is 80 ° C. to 120 ° C. There is (Fig. 4). Further, in the present embodiment, the curing reaction proceeds at 80 ° C. or higher. Assuming that the temperature rise rate of the first thermosetting resin at temperatures Ta (° C.) to Tb (° C.) is R1 and the temperature rise rate of the second thermosetting resin is R2, the above relationship (Equation 1) is satisfied. There is. As described above, the temperature rise rate in the temperature range in which the curing reaction of the first thermosetting resin proceeds and the inclusion gas of the first thermosetting resin is released (moved) is large is the above (Equation 1). When the heating environment is adjusted so as to satisfy the above relationship, the gelling time of the second thermosetting resin becomes slower than the gelling time of the first thermosetting resin.

FIG. 9 is a diagram conceptually showing changes in 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 with time. According to the method for manufacturing a 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 heating rate, the gelation of the second thermosetting resin is achieved. The second standard gelation time, which is the time of, is longer than the first standard gelation time, which is the time until gelation of the first thermosetting resin. Then, when the fiber-wrapped tank body is heated in the heating furnace, it is heated so that the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin. Therefore, in a state where the second thermosetting resin has fluidity, the first thermosetting resin gels, so that the gas contained in the uncured layer of the first thermosetting resin is almost completely released, and then the second heat is generated. The curable resin gels. Even if the contained 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, the first 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. Modification example:
(1) The fluid contained in the high-pressure tank 100 is not limited to the above-mentioned compressed hydrogen, and may be a high-pressure fluid such as compressed nitrogen.

(2) As the fibers contained in the reinforcing layer 20 and the protective layer 25, various fibers capable of forming a fiber reinforced resin such as carbon fiber, glass fiber, aramid fiber, Dyneema fiber, Zylon fiber, and boron fiber can be used. .. It is preferable to select fibers so that the reinforcing layer 20 has pressure resistance and the protective layer 25 has higher impact resistance than the reinforcing layer 20. When carbon fiber is used as the fiber of the reinforcing layer 20 and glass fiber or aramid fiber is used as the fiber of the protective layer 25, the reinforcing layer 20 having high pressure resistance and the protective layer 25 having higher impact resistance than the reinforcing layer 20 are used. Is formed, which 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 a desired impact resistance higher than that of the reinforcing layer 20 as the protective layer 25. When the protective layer 25 is formed only of resin, the protective layer 25 can be formed by spraying the resin and then heating it by a well-known method such as spray coating. For example, in the above embodiment, when the protective layer 25 is formed only of the second thermosetting resin, the carbon fiber impregnated with the first thermosetting resin is wound around the liner 10 and then spray-coated or the like. The reinforcing layer 20 and the protective layer 25 are formed by spraying the second thermosetting resin and then heating to cure the first thermosetting resin and the second thermosetting resin by the well-known method of. be able to.

(4) In the above embodiment, the same type of resin (epoxy resin) having a different gelation temperature was used as the first thermosetting resin and the second thermosetting resin, but the first thermosetting resin and the second thermosetting resin were used. The sex 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, the reverse may be made. 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 heating rate, the second thermosetting resin gels. The second standard gelation time, which is the time until gelation, is adjusted to be longer than the first standard gelation time, which is the time until gelation of the first thermosetting resin. The difference in gelation time (difference in gelation temperature) can be set as appropriate. Then, in the heating step by the heating furnace, the convex portion on the surface of the high-pressure tank is heated by heating so that the gelation time of the second thermosetting resin is longer than the gelation time of the first thermosetting resin. The formation can be suppressed.

(5) The heating method (set temperature, maintenance time) in the heating furnace of the method for manufacturing the high-pressure tank is not limited to the above embodiment. Further, the method for determining the heating environment is not limited to the above embodiment. However, as in the above embodiment, the target value of the temperature rise rate of each thermosetting resin (for example, the temperature rise rate estimated in the third method of determining the heating environment of the embodiment) is determined, and the first. (1) A heating environment so that each temperature rise rate in a temperature range at which the curing reaction of the thermosetting resin proceeds and in a temperature range in which the contained gas of the first thermosetting resin is released (moved) is large, approaches the target value. Can be relatively easily heated so that the gelling time of the second thermosetting resin is longer than the gelling time of the first thermosetting resin.

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

The disclosed technology is not limited to the above-described embodiments and modifications, and can be realized with various configurations within a range that does not deviate from the gist thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems. , It is possible to replace or combine as appropriate in order to achieve a part or all of the above-mentioned effects. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 ... Liner 20 ... Reinforcing layer 25 ... Protective layer 30 ... Base 40 ... Base 100 ... High pressure tank 102 ... Cylindrical part 104 ... Dome part T1 ... First gelling temperature T2 ... Second gelling temperature Tm1 ... Measuring point Tm2 ... Measurement Point t1 ... 1st gelation time t2 ... 2nd gelation time

Claims (1)

It is a method of manufacturing a high-pressure tank.
(A) A step of forming a first thermosetting resin uncured layer containing an uncured first thermosetting resin and fibers on a liner.
(B) 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.
(C) After the step (B), the second gelling time, which is the time from the outside of the uncured layer of the second thermosetting resin until the second thermosetting resin gels, is the first. 1 A step of curing the first thermosetting resin and the second thermosetting resin by heating so as to be longer than the first gelation time, which is the time until the thermosetting resin gels.
With
In the second thermosetting resin, when each of the first thermosetting resin and the second thermosetting resin is heated at the same heating rate, the second thermosetting resin gels. the second standard gel time is the time until, Ri longer der than the first standard gel time is the time until gelation of the first thermosetting resin,
The process in the step (C) is
The gelling temperature of the single thermosetting resin and the second thermosetting resin, which were measured by heating at a plurality of temperatures,
The first thermosetting resin of the first thermosetting resin uncured layer formed on the liner and the first thermosetting resin uncured layer of the second thermosetting resin uncured layer, which were measured by heating at a plurality of temperatures. 2 The rate of temperature rise of thermosetting resin and
That it has been established on the basis of the method for manufacturing a high-pressure tank.

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