JP6146330B2 - Manufacturing method of high-pressure tank - Google Patents

Description

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

  A conventional high-pressure tank has a carbon fiber reinforced plastic layer or a glass fiber reinforced plastic layer (hereinafter collectively referred to as a “fiber reinforced plastic layer” or “fiber reinforced” around a liner having a dome at both ends. It is called “resin layer”). Such a high-pressure tank usually forms a work in which a fiber reinforced plastic material (also referred to as a “fiber reinforced resin material”) is wound around a liner, and the work is heated (heated) to form a fiber reinforced plastic material layer ( It is also produced by curing a fiber reinforced resin material layer). For example, Patent Document 1 describes the following high-pressure tank manufacturing method. When the fiber reinforced plastic material layer is cured by raising the temperature of the curing furnace, the internal pressure of the workpiece is increased and adjusted so that the boiling temperature of water charged into the workpiece becomes the curing temperature. When the temperature of the workpiece is cooled by lowering the temperature of the curing furnace, the internal pressure of the workpiece is released and the outside air is supplied into the workpiece to cool the workpiece from the inside.

JP 2011-012764 A

  Here, the liner is often formed using a resin material having a gas barrier property, for example, a nylon resin material, from the viewpoint of weight reduction. For this reason, in the manufacturing method of Patent Document 1, when outside air is supplied to the inside of the workpiece while the workpiece is heated by heating, oxygen, water, or the like contained in the outside air adheres to the liner surface, and the liner surface is oxidized. In addition, there is a problem that the liner deteriorates due to moisture absorption into the liner. Further, during the curing, a part of the gas (usually a gas contained in the air) existing in the work may permeate the liner and diffuse into the liner and dissolve. The gas dissolved in the liner similarly causes deterioration of the liner. However, since the pressure of the gas dissolved in the liner is very small, there is also a problem that it is difficult to remove by the manufacturing method of Patent Document 1. Further, there is a problem that the cooling method for supplying the cooling of the outside air is not sufficient in terms of shortening the manufacturing time. In addition, it has been desired to reduce the cost and facilitate the manufacturing of the high-pressure tank.

  In order to achieve at least a part of the problems described above, the present invention can be implemented as the following forms.

(1) According to one aspect of the present invention, there is provided a method for manufacturing a high-pressure tank having a structure in which the periphery of a liner is covered with a fiber reinforced plastic layer. The high-pressure tank manufacturing method includes: (i) preparing a work in which a fiber reinforced resin material is wound around a liner; and (ii) having a boiling point lower than a curing temperature for curing the fiber reinforced resin material. Enclosing a liquid having the inside of the workpiece and heating the workpiece to the curing temperature; and (iii) reducing the pressure inside the workpiece by suction after completion of the step (ii). Prepare. According to the method of manufacturing a high-pressure tank of the above aspect, the liquid enclosed in the work boils and the pressure inside the work rises, whereby the temperature rise inside the work is accelerated, and the temperature of the work reaches the curing temperature. Ascent is assisted. In addition, by reducing the pressure inside the work by suction after the heating is completed, the temperature inside the work can be rapidly lowered without supplying outside air to the work. Compared to cooling the work with outside air. And can be cooled in a short time. Further, since cooling is possible by sucking the liquid and gas inside the workpiece without supplying outside air, the problem of liner deterioration described in the problem can be improved. Further, if the pressure inside the work is reduced to a pressure lower than the outside air, preferably a pressure value determined to be a vacuum state, the gas diffused and dissolved inside the liner described in the problem can be removed. is there.

  In addition, this invention can be implement | achieved with various forms, for example, can be implement | achieved in aspects, such as a manufacturing method of a high pressure tank, a manufacturing apparatus of a high pressure tank.

It is a schematic sectional drawing which shows typically the composition of the high-pressure tank manufactured by the manufacturing method of the embodiment of the present invention. It is explanatory drawing which shows the example of the manufacturing apparatus which enforces the manufacturing method of the high pressure tank as embodiment of this invention. It is explanatory drawing which shows the procedure of the manufacturing method of the high pressure tank as embodiment of this invention. It is explanatory drawing which shows the relationship between the temperature of the workpiece | work and the internal pressure of a workpiece | work in the manufacturing method of FIG.

  FIG. 1 is a schematic cross-sectional view schematically showing the configuration of a high-pressure tank manufactured by the manufacturing method of the embodiment of the present invention. The high-pressure tank 10 is configured by covering a liner 110 with a fiber reinforced resin layer (also referred to as a “fiber reinforced plastic layer”) 140, and the bases 120 and 130 are centered on the liner axis CX at both ends in the liner axis CX direction. It protrudes in the CX direction.

  The liner 110 is a hollow tank container centered on the liner axis CX, and is a joined product of a pair of liner parts divided into two at the center in the longitudinal direction along the liner axis CX. Each of the two-part liner parts is molded with a resin having an appropriate gas barrier property, such as nylon resin, and the liner parts of the molded parts are joined and laser welded to the joined parts. Is formed. Through this part joining, the liner 110 includes spherical dome portions 112 on both sides of the cylindrical cylinder portion 111 in the liner axis CX direction, and is an internal space for storing gas (hereinafter also referred to as “storage space”). 114).

  The fiber reinforced resin layer (fiber reinforced plastic layer) 140 is a fiber reinforced resin material (heated) that is wound so as to cover the liner 110 and the peripheral portion excluding the opening facing the liner axis CX direction of the caps 120 and 130. A fiber impregnated with a curable resin material) is cured to coat a part of the outer surface of the liner 110 and the caps 120 and 130.

  The caps 120 and 130 are made of a lightweight metal such as aluminum or an alloy thereof, and are provided in the dome portion 112 of the liner 110 around the liner axis CX. A female screw is engraved on the inner peripheral surface of the opening of the base 120, 130, and the functional part is screwed with the female screw of the functional part such as a pipe or a valve assembly. It is configured so that it can be screwed in. In FIG. 1, an example in which the valve assembly VA is connected to the base 120 is indicated by a two-dot chain line.

  For example, in the high-pressure tank 10 provided in the fuel cell system, the storage space 114 and a gas flow path (not shown) are connected via the valve assembly VA, and the storage space 114 is filled with hydrogen as a fuel gas. At the same time, hydrogen is released from the storage space 114 and used for power generation of the fuel cell.

  FIG. 2 is an explanatory diagram illustrating an example of a manufacturing apparatus that performs a method for manufacturing a high-pressure tank according to an embodiment of the present invention. The manufacturing apparatus 1000 includes a curing furnace 20, rotating rods (rotating units) 30 and 40, a liquid supply / discharge unit 50, and a control unit 60. The curing furnace 20 includes a furnace space in which a work 10P before formation of a high-pressure tank having an uncured fiber reinforced resin material layer 140P is set. The work 10P is attached to the openings of the caps 120 and 130. It is set in the furnace (furnace space) via the rotating rods 30 and 40. In the curing process described later, the work 10P can be evenly heated by appropriately rotating the rotating bars 30 and 40 by a driving device (not shown).

  The liquid supply / discharge unit 50 includes a liquid supply unit 510, a pump 520, a valve 530, a liquid pipe 540, a gas pipe 550, and a connection pipe 560. The connection pipe 560 is a pipe that extends from the valve 530 to the internal space 114 of the workpiece 10 </ b> P through the rotary rod 30. The connection pipe 560 is fixed to the inside of the rotary rod 30 via a non-illustrated sealed bearing, and the rotary bar 30 can rotate independently of the connection pipe 560. The liquid pipe 540 is a pipe that connects the liquid supply unit 510 and the valve 530, and the gas pipe 550 is a pipe that connects the pump 520 and the valve 530.

  The valve 530 can be independently operated to open and close between the liquid pipe 540 and the connection pipe 560 and open and close between the gas pipe 550 and the connection pipe 560. Therefore, the liquid can be supplied from the liquid supply unit 510 to the internal space 114 of the workpiece 10P by operating the valve 530. Further, by operating the valve 530, the pump 520 can suck gas and liquid from the internal space 114 of the workpiece 10P, and can supply outside air to the internal space 114 of the workpiece 10P. Further, the valve 530 may be provided with an opening / closing function that enables intake of outside air independently, and the interior space 114 may be in a released state when the workpiece 10P is set.

  The control unit 60 is a computer, and controls the operations of the curing furnace 20, the rotating rods 30 and 40, the liquid supply unit 510, the pump 520, and the valve 530, so that the fiber reinforced resin material of the workpiece 10 </ b> P by the manufacturing apparatus 1000 is controlled. The curing process of the layer 140P is executed.

  FIG. 3 is an explanatory diagram showing a procedure of a method for manufacturing a high-pressure tank as an embodiment of the present invention. FIG. 4 is an explanatory diagram showing the relationship between the workpiece temperature and the workpiece internal pressure in the manufacturing method of FIG.

  First, in step S10 of FIG. 3, the workpiece 10P before forming the high-pressure tank having the uncured fiber reinforced resin material layer 140P is set in the furnace of the curing furnace 20 (see FIG. 2). The workpiece 10P is prepared, for example, by forming a fiber reinforced resin material layer 140P by winding a fiber reinforced resin material around a liner 110 having caps 120 and 130 at both ends by a filament winding method (hereinafter referred to as FW method). Is done. An epoxy resin is generally used as the thermosetting resin material of the fiber reinforced resin material, but a thermosetting resin such as a polyester resin or a polyamide resin can also be used. In addition, as a reinforcing fiber (sliver fiber) wound around the liner by the FW method, glass fiber, carbon fiber, aramid fiber, or the like is used, and plural types (for example, glass fiber and carbon fiber) are wound by the FW method. By sequentially performing the above, the fiber reinforced resin material layer 140P can be formed by laminating resin material layers made of different fibers.

  Next, in step S20, a liquid is sealed inside the tank (internal space 114) of the workpiece 10P. As described above, the valve 530 and the liquid supply unit 510 are controlled by the control unit 60, and the liquid is supplied from the liquid supply unit 510 to the inside of the tank via the liquid pipe 540, the valve 530, and the connection pipe 560. To be executed. The liquid is a temperature for curing the thermosetting resin material contained in the fiber reinforced resin material (hereinafter referred to as “curing temperature”) at the pressure inside the tank (eg, atmospheric pressure) at the time of sealing. Various liquids having a boiling point Tb at a temperature lower than Tc are used. The liquid may be not only a pure liquid but also a solvent. For example, water having a curing temperature Tc of 150 ° C. and a boiling point Tb of 100 ° C. or alcohol having a lower temperature than 100 ° C. is used. In this example, water is used. The amount of liquid to be sealed will be described later.

  In step S30, the inside of the curing furnace 20 is heated so that the temperature of the workpiece 10P (hereinafter referred to as “work temperature”) becomes the curing temperature Tc. At this time, as shown in FIG. 4, the workpiece temperature rises with the passage of time from the temperature at the start of heating. The pressure inside the tank at the start of heating (hereinafter referred to as “in-work pressure”) is defined as pressure P1. The pressure P1 is normally set to atmospheric pressure (standard atmospheric pressure (1 atmospheric pressure)).

  Here, as shown in FIG. 4, as the work temperature rises due to heating, the liquid (water) inside the tank starts to evaporate, and when the work temperature reaches the boiling point Tb at time t1, the liquid in the work Since it boils and vaporizes, the internal pressure of the workpiece rises rapidly. At this time, since the volume inside the tank is constant, PV / T = k (V is the volume, P is the pressure in the volume, T is the temperature in the volume, and k is a constant) according to the increase in the pressure in the workpiece. The temperature inside the tank rises due to the adiabatic compression effect. For this reason, the temperature rise inside the workpiece is added to the temperature rise from the outside of the workpiece due to heating, and the rise in the workpiece temperature is accelerated, so that the workpiece temperature rises earlier, and the pressure in the workpiece becomes the pressure P2 at time t2. The workpiece temperature reaches the curing temperature Tc. The subsequent heating of the curing furnace 20 is controlled so that the furnace temperature and the workpiece temperature maintain the curing temperature Tc during the time until the heat treatment for curing is completed (curing completion time).

  Note that the amount of liquid enclosed in step S20 in FIG. 3 is the difference between the workpiece pressure (pressure P2) at the curing temperature Tc and the workpiece pressure (pressure P1) at the start of overheating, that is, the workpiece temperature described above is the curing temperature. The pressure is adjusted according to the pressure in the workpiece to be pressurized before reaching Tc. If the amount of liquid is small, the amount of pressurization is small, so the degree of assist in temperature rise is reduced, and the time for raising the workpiece temperature to the curing temperature Tc is lengthened. Also, if the amount of liquid is too large, it takes time to increase the temperature pressure of the liquid, whereas the increase in the internal pressure of the workpiece after reaching the boiling point is accelerated, and the time required to reach the curing temperature Tc after reaching the boiling point Tb. However, there is a possibility that the pressure inside the workpiece becomes too high and the liner 110 is deformed. Therefore, the amount of liquid to be sealed is adjusted in consideration of the time required to assist the rise and reach the curing temperature Tc, the pressure resistance of the liner 110, and the like.

  In Step S40, the process waits until a time (hereinafter referred to as “curing completion time”) from the time when the curing temperature Tc is reached until the curing process is completed. During this standby, as described above, in the curing furnace 20, the heating control is executed so that the furnace temperature and the workpiece temperature maintain the curing temperature Tc.

  In step S50, at the time t3 when the curing completion time elapses, heating in the furnace 20 is stopped and cooling from the outside of the work 10P by natural heat radiation is started, and in step S60, the inside of the tank is enclosed. The inside of the tank is depressurized by sucking gas (here, air containing water vapor) and liquid (here, water) when remaining. As described above, the valve 530 and the pump 520 are controlled by the control unit 60 (FIG. 2), and the gas inside the tank is sucked by the pump 520 through the connection pipe 560, the valve 530, and the gas pipe 550. To be executed.

  Here, as shown in FIG. 4, the internal pressure of the work decreases due to suction. At this time, the temperature inside the tank decreases due to the effect of adiabatic expansion according to the decrease in the pressure inside the work, contrary to the temperature rise inside the tank when the work internal pressure rises, and the temperature of the work 10P also changes accordingly. It is accelerated and lowered than cooling by natural heat dissipation. When the workpiece temperature falls to the boiling point Tb at time t3, the vapor (here, water vapor) that is vaporized and contained in the gas (here, air) is liquefied, and the internal pressure of the workpiece is suddenly lowered (rapidly). In response to this, the temperature inside the tank and the workpiece 10P also drop rapidly. As a result, the workpiece 10P can be cooled in a short time.

  The pressure reduction in step S60 is executed until the work internal pressure reaches the pressure P3, and then ends. The pressure P3 is preferably set to be equal to or lower than the starting pressure P1. In this example, it is assumed that the pressure P3 is set to a value that is determined to be a vacuum state (≈0 atm).

  As described above, in the method for manufacturing a high-pressure tank according to the present embodiment, the temperature inside the tank is increased by the effect of adiabatic compression obtained by boiling the liquid sealed inside the tank of the workpiece 10P and increasing the pressure inside the tank. To increase the workpiece temperature and accelerate the time for the workpiece temperature to rise to the curing temperature Tc. Further, when the work 10P is cooled after finishing the curing process by heating, the pressure inside the work is reduced, thereby generating a cooling effect by adiabatic expansion, cooling the inside of the tank, and rapidly cooling the work 10P. be able to. Furthermore, since the outside air is not supplied to the inside of the tank when the workpiece 10P is cooled, the liner described by the problem is caused by oxidation of the liner surface caused by adhesion of oxygen, water, etc. to the surface of the liner 110 or moisture absorption into the liner. 110 degradation can be suppressed. Further, since the pressure in the tank is reduced to a pressure P3 set to a value determined to be in a vacuum state (≈0 atm), the gas dissolved in the liner described in the problem can be excluded from the inside of the liner. it can. Note that the pressure P3 to be depressurized does not necessarily have to be a vacuum value, and may be set to a value equal to or lower than the pressure of the gas dissolved in the liner. If this is not taken into consideration, the value may be equal to or less than the starting pressure P1.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. 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-described 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 ... High pressure tank 10P ... Workpiece 20 ... Curing furnace 30, 40 ... Rotating rod 50 ... Liquid supply / discharge part 60 ... Control part 110 ... Liner 111 ... Cylinder part 112 ... Dome part 114 ... Internal space (storage space)
DESCRIPTION OF SYMBOLS 120,130 ... Base 140P ... Fiber reinforced resin material layer 510 ... Liquid supply part 520 ... Pump 530 ... Valve 540 ... Liquid piping 550 ... Gas piping 560 ... Connection piping 1000 ... Manufacturing apparatus VA ... Valve assembly CX ... Liner axis Tb ... Boiling point Tc: Curing temperature

Claims (1)

A method for producing a high-pressure tank having a structure in which a periphery of a liner is covered with a fiber reinforced resin layer,
(I) preparing a work in which a fiber reinforced resin material is wound around a liner;
(Ii) enclosing a liquid having a boiling point lower than a curing temperature for curing the fiber-reinforced resin material in the workpiece, and heating the workpiece to the curing temperature;
(Iii) After the completion of the step (ii), the heating of the workpiece is stopped to naturally cool the workpiece, and the adiabatic expansion effect generated by reducing the pressure inside the workpiece by suction is utilized. Cooling the workpiece ; and
A method for manufacturing a high-pressure tank.

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