JP2006242247A - Gas vessel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas vessel allowing liner components to be suitably jointed to each other and capable of improving productivity; and to provide its manufacturing method. <P>SOLUTION: This gas vessel includes: a resin liner 11 composed by jointing the liner components 21 and 22 each having at least a hollow cylindrical part to each other; and a reinforcing layer 12 arranged in the circumference of the resin liner 11. A joint part 34 of the liner component 21 is jointed to a joint part 44 of the liner component 22 throughout the circumferential direction by laser welding. The joint part 34 and the joint part 44 are formed of a laser-transmitting resin and a laser-absorbing resin, respectively. By imparting a pressure difference between the inside and the outside of the liner components 21 and 22 in the state in contact with each other in the laser welding, adhesion between the joint parts 34 and 44 is increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas container for storing a gas such as hydrogen, and more particularly to a gas container in which a resin liner serving as an inner shell is formed by joining a plurality of liner constituent members and a method for manufacturing the same.

Conventionally, as a gas container for storing hydrogen and CNG (compressed natural gas), from the viewpoint of weight reduction, the inner shell is composed of a resin liner, and the outer peripheral surface of the resin liner is reinforced with a reinforcing layer (outer shell) such as FRP. What has been developed. As this type of resin liner, for example, a pair of bowl-shaped (substantially cylindrical members) liner constituent members are formed of a thermoplastic resin such as polyethylene, and the ends of the pair of liner constituent members are welded together by hot plate welding. What was joined by doing is known (for example, refer to patent documents 1).
JP 2004-211783 A (FIGS. 2 and 5)

  However, in the joining method in which the liner constituent members are welded to each other by heat plate, it takes much time and cost to manufacture the resin liner. Further, in the hot plate welding method, melting burrs are easily generated, and it is difficult to manage the positioning accuracy between the liner constituent members. Furthermore, the liner body may be deformed by the influence of heating, and it is difficult to control the heat.

  An object of the present invention is to provide a gas container and a method for manufacturing the same that can appropriately join liner constituent members and improve productivity.

  The gas container of the present invention is a gas container having a resin liner formed by joining a plurality of liner components each having a hollow cylindrical shape, and a reinforcing layer disposed on the outer periphery of the resin liner. The joint portions of the plurality of liner constituent members are joined to each other by laser welding.

  In addition, another gas container of the present invention has a resin liner formed by joining a plurality of liner components each having a hollow cylindrical shape, and a reinforcing layer disposed on the outer periphery of the resin liner. A gas container, wherein a joint portion of one liner constituent member and a joint portion of another liner constituent member are joined to each other has a laser weld portion in which these joint portions are joined to each other by laser welding. It is what.

  According to these configurations, in the process of manufacturing the resin liner, since the joining portion of one liner constituent member and the joining portion of another liner constituent member are joined by laser welding, the resin liner can be obtained in a short time and at low cost. Can be configured. Therefore, the productivity of the gas container can be increased. In addition, by using laser welding, the joints can be locally heated at a low temperature, so that the thermally affected portion can be minimized with respect to the liner component member, resulting in melting burrs and the like. You don't have to.

  Here, the “liner constituent member having at least a part (one end side) of a hollow cylindrical shape” includes that the liner constituent member has a cylindrical shape, an annular shape, a bowl shape, a dome shape or the like as a whole. For example, when a resin liner is constituted by a pair of (half-split) liner constituent members, each liner constituent member is formed in a bowl shape as a whole. Further, when the resin liner is constituted by three or more liner constituent members, the liner constituent members at both ends of the resin liner are each formed in a bowl shape as a whole, and the liner constituent members located between them are hollow as a whole. It is formed in a cylindrical shape or an annular shape.

  In the case of the gas container according to the present invention, it is preferable that the joint portions are joined to each other by laser welding over the circumferential direction of the resin liner.

  According to this structure, the whole circumference | surroundings of joining parts are line-welded with a laser. Thereby, the leak of the gas from the joint part of junction parts is blocked | prevented and it becomes possible to ensure the airtightness of a resin liner appropriately.

In these cases, it is preferable that the joint portion of one liner constituent member to be joined to each other is made of a laser transmitting member, and the joint portion of the other liner constituent member is made of a laser absorbing member.
Alternatively, it is preferable that one liner constituting member joined to each other is made of a laser transmitting member, and the other liner constituting member is made of a laser absorbing member.

  According to these configurations, in the process of manufacturing the resin liner, when laser is irradiated from the laser transmissive joint side, the laser absorptive joint is heated and melted, and the laser transmission is performed by heat transfer from the joint. The joints of these are heated and melted.

  As described above, the bonding portions can be appropriately bonded to each other by giving the bonding portions the property of transmitting or absorbing the laser. Further, the characteristics of this type of laser may be given only to the joint portion, but the liner constituent member can be easily manufactured by giving the entire liner constituent member including the joint portion.

  In this case, it is preferable that the joining portion made of the laser-transmitting member is located on the outside of the resin liner, and the joining portion made of the laser-absorbing member is located on the inside of the resin liner.

  According to this configuration, in the process of manufacturing the resin liner, the laser beam can be irradiated from the outside of the resin liner (the outside of the liner constituent member) to easily join the joint portions. That is, in the process of manufacturing the resin liner, it is not necessary to position the laser irradiation device inside the liner constituting member, and the joining portions can be joined with good workability. This is also useful for reducing the size of the resin liner.

  In these cases, in the vicinity of the laser welded portion between the joint portion of one liner constituent member and the joint portion of the other liner constituent member, there is an engagement structure that engages these joint portions so as to closely contact each other. It is preferable to be provided.

  According to this configuration, in the process of manufacturing the resin liner, laser welding can be performed while the bonding portions are brought into close contact with each other with the engagement structure, so that poor welding of laser welding can be suppressed and bonding accuracy can be increased. . Further, by providing the engagement structure, the jig can be simplified or unnecessary. Here, the engagement structure includes, for example, snap fitting, press fitting, and screwing.

  In these cases, at least one of the plurality of liner constituting members has a communication portion for communicating the hollow inside and the outside of the resin liner on the opposite side to the joint portion to be joined to the other liner constituting member. It is preferable that

  According to this configuration, the gas can be filled in or discharged from the hollow interior of the resin liner via the communicating portion.

  The method for manufacturing a gas container according to the present invention is a method for manufacturing a gas container having a resin liner formed by joining a plurality of liner components each having a hollow cylindrical shape, and should be joined to each other. The joint portion of the other liner constituent member should be composed of a laser transmissive member, and the joint portion of the other liner constituent member should be composed of a laser absorbing member, and should be joined to each other after the first step. A second step of bringing the joint portions of the liner constituent members into contact with each other, and after the second step, laser is irradiated from the joint portion side made of a laser transmissive member, and the joint portions in contact are joined together by laser welding. And a third step.

  According to this configuration, first, a laser transmitting or absorbing characteristic is imparted to the joining portion of the liner constituent member, and then the laser is transmitted from the laser transmitting joining side while bringing the joining portions into contact with each other. Irradiate. The laser-absorbing joint is heated and melted by laser irradiation, and the laser-permeable joint is heated and melted by heat transfer from the joint, and then cooled and solidified, so that the interface between the joints is Be joined.

  As described above, since the laser welding is used for joining the liner constituent members, the resin liner can be configured in a short time and at a low cost. In addition, since the joint portions can be locally heated, it is possible to minimize the thermal influence on the liner constituting member, and it is not necessary to cause a melting burr or the like.

  In this case, the second step is performed by bringing the laser-transmitting bonding portion into contact with the laser-absorbing bonding portion from the outside, and the third step is a laser irradiation apparatus disposed outside the liner constituting member. Therefore, it is preferable to perform the irradiation by irradiating the laser from the laser-transmitting joint side.

  According to this configuration, it is not necessary to position the laser irradiation device inside the liner constituting member, and the joining portions can be easily joined with good workability.

  In these cases, it is preferable that the third step includes irradiating a laser with a pressure difference applied between the inside and outside of the two liner constituent members to be joined to each other.

According to this configuration, the joints are laser-welded in a state where the degree of adhesion between the joints is increased by the pressure difference. Thereby, the welding defect of laser welding can be suppressed and joining accuracy can be improved. Further, by increasing the joining accuracy, it is possible to appropriately ensure the strength and airtightness of the resin liner.
Here, the application of the pressure difference may be stopped when the bonding reaction between the bonded portions has progressed to some extent by laser irradiation. In other words, the pressure difference may be applied for at least one time during the irradiation from the start of the laser irradiation.

  In this case, it is preferable that the application of the pressure difference in the third step is performed by adjusting at least one of the internal pressure and the external pressure of the two liner constituent members to be joined to each other.

  In this case, it is preferable that the application of the pressure difference in the third step is performed by setting the insides of the two liner constituting members to be joined to each other substantially in a sealed state and reducing or pressurizing the sealed space.

According to this configuration, since the pressure in the sealed space inside the two liner constituent members is adjusted, the above-described pressure difference can be applied more simply than adjusting these external pressures.
Here, the pressurization of the sealed space includes, for example, the case of injecting a gas having a temperature higher than that of the outside of the sealed space in addition to the case of injecting the compressed gas therein.

  In this case, it is preferable that the application of the pressure difference in the third step is performed by depressurizing or pressurizing the sealed space via a communication portion provided in at least one of the two liner constituent members to be joined to each other. .

  According to this configuration, the sealed space can be depressurized or pressurized using the communication part effectively. In addition, after manufacturing as a gas container, gas can be filled in or discharged from the hollow interior of the resin liner through this communication portion.

  In these cases, in the second step, the joint portions of the two liner constituent members to be joined to each other are arranged so as to overlap in the axial direction of the liner constituent members, and the overlapped portions are brought into contact with each other. It is preferred that this is done.

  According to this configuration, for example, the contact area between the joints can be increased as compared with a case where the joints are simply abutted. In particular, since the overlapping portions in the axial direction are in contact with each other, the pressure difference applied during laser welding increases the adhesion between the joints, and the joint accuracy between the joints can be further enhanced. .

  In these cases, it is preferable to further include a step of performing an annealing process between the second step and the third step in a state where the joint portions of the two liner constituent members to be joined to each other are brought into contact with each other.

  According to this configuration, the liner constituent member self-shrinks due to the annealing treatment, and the degree of adhesion between the joint portions increases. Thereby, in the state which the adhesion degree of junction parts increased, the junction parts can be laser-welded, and it becomes possible to raise the joining precision. Further, since the degree of adhesion is increased by the annealing treatment, for example, a device such as a pump for applying the pressure difference can be reduced in size and simplified.

  In these cases, in the third step, laser welding is performed on the joint portions in contact with each other in the circumferential direction of the liner constituent member while rotating the two liner constituent members to be joined relative to the laser irradiation apparatus. It is preferable to be performed.

  According to this configuration, since the two liner constituent members are rotated relative to the laser irradiation apparatus, the entire circumference of the joints is line-welded by the laser. Thereby, it becomes possible to ensure the airtightness of the resin liner appropriately.

  Here, “relatively rotate” means to rotate only two liner components to be joined, to rotate only the laser irradiation device, to rotate both in the same direction or in the opposite direction, Is included. In particular, rotating only two liner components among them can be the simplest in positioning and device configuration.

  In these cases, it is preferable that the third step is performed in a low oxygen atmosphere.

  According to this configuration, it is possible to suppress oxidation of the bonded portion melted by laser irradiation. As a result, it is possible to suppress welding defects such as burning due to oxidation during laser welding and laser transmission defects associated therewith. Here, the low oxygen atmosphere refers to an atmosphere that is lower in oxygen than air, and includes, for example, an inert gas atmosphere or a substantially vacuum state.

  In these cases, the first step may be performed by configuring one liner constituent member to be bonded to each other with a laser-transmitting member and configuring the other liner constituent member with a laser-absorbing member. ,preferable.

  According to this configuration, the entire liner constituent member including the joint portion is a member having characteristics with respect to the laser, so that the liner constituent member can be simplified compared with the case where only the joint portion has such characteristics. Can be manufactured.

  In this case, after the third step, a step of shaving at least one outer peripheral surface of the two liner constituent members so that a joint between the outer peripheral surfaces of the two liner constituent members joined by laser welding is flush. It is preferable to provide.

  For example, as described above, when the joint portions are overlapped with each other in the axial direction, unevenness may occur on the outer peripheral surface of the joint. Therefore, by providing the above steps, the outer peripheral surface of at least one liner constituent member can be shaved so that the joint of the outer peripheral surface can be flush. This is useful, for example, in providing a reinforcing layer on the outer periphery of the resin liner.

  According to the gas container and the manufacturing method thereof of the present invention, since the laser welding is used for joining the liner constituent members, the liner constituent members can be joined appropriately, and productivity can be improved.

  Hereinafter, a gas container and a manufacturing method thereof according to preferred embodiments of the present invention will be described with reference to the accompanying drawings. This gas container has a resin liner in which a plurality of liner constituent members are joined by laser welding. Below, the structure of a gas container is demonstrated first, and the manufacturing method of a gas container is demonstrated after that. In the second to fifth embodiments, a modification example of the manufacturing method will be mainly described, and in the remaining embodiments, other structures of the gas container will be mainly described. In the second and subsequent embodiments, portions common to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

<First Embodiment>
As shown in FIG. 1, the gas container 1 includes a sealed cylindrical container body 2 as a whole, and caps 3 and 3 attached to both ends of the container body 2 in the longitudinal direction. The inside of the container body 2 is a storage space 5 for storing various gases. The gas container 1 can be filled with a normal pressure gas, or can be filled with a gas whose pressure is increased as compared with the normal pressure. That is, the gas container 1 of the present invention can function as a high-pressure gas container.

  For example, in a fuel cell system, the fuel gas prepared in a high pressure state is decompressed and used for power generation of the fuel cell. The gas container 1 of the present invention can be applied to store high-pressure fuel gas, and can store hydrogen as fuel gas, compressed natural gas (CNG gas) as raw fuel, and the like. The pressure of hydrogen filled in the gas container 1 is, for example, 35 MPa or 70 MPa, and the pressure of CNG gas is, for example, 20 MPa. Hereinafter, a high-pressure hydrogen gas container will be described as an example.

  The container body 2 has a two-layer structure of an inner resin liner 11 (inner shell) having gas barrier properties and a reinforcing layer 12 (outer shell) disposed on the outer periphery of the resin liner 11. The reinforcing layer 12 is made of, for example, FRP containing carbon fiber and an epoxy resin, and is wound around so as to cover the outer surface of the resin liner 11.

  The base 3 is made of a metal such as stainless steel, and is provided at the center of the hemispherical end wall portion of the container body 2. A female screw is engraved on the inner peripheral surface of the opening of the base 3, and functional parts such as piping and a valve assembly 14 (valve body) can be screwed into the base 3 via the female screw. ing. In FIG. 1, an example in which the valve assembly 14 is provided only on one of the caps 3 and 3 is indicated by a two-dot chain line.

  For example, the gas container 1 on the fuel cell system is connected between the storage space 5 and an external gas flow path (not shown) via a valve assembly 14 in which piping elements such as valves and joints are integrated. The storage space 5 is filled with hydrogen and hydrogen is released from the storage space 5. As will be described later, in the process of manufacturing the gas container 1, a pipe is connected to the base 3 to adjust the pressure in the storage space 5. In addition, although the nozzle | cap | die 3,3 was provided in the both ends of the gas container 1, of course, you may provide the nozzle | cap | die 3 only in one edge part.

  The resin liner 11 is constituted by joining a pair of liner constituent members 21 and 22 (split bodies) having substantially the same shape divided into two at the center in the longitudinal direction by laser welding. That is, the resin liner 11 inside the hollow is configured by joining the liner constituting members 21 and 22 of the half hollow body by laser welding.

  The pair of liner constituting members 21, 22 have body portions 31, 41 extending a predetermined length in the axial direction of the resin liner 11. Both end sides in the axial direction of the body portions 31 and 41 are open.

  One liner constituting member 21 includes a return portion 32 formed at a reduced diameter end portion on one end side of the body portion 31, a communication portion 33 opened in the center of the return portion 32, and the other end of the body portion 31. And a joining portion 34 formed at the substantially cylindrical end portion on the side.

  The other liner constituting member 22 includes a return portion 42 formed at a reduced diameter end portion on one end side of the barrel portion 41, a communication portion 43 opened at the center of the return portion 42, and the other end of the barrel portion 41. And a joining portion 44 formed at the substantially cylindrical end portion on the side.

  The return portions 32 and 42 function to secure the strength of the liner constituent members 21 and 22. The caps 3 and 3 are located between the outer peripheral surfaces of the return portions 32 and 42 and the end portions of the reinforcing layer 12. When the base 3 is provided only at one end, the return portions 32 and 42 and the communication portions 33 and 43 are not formed on one of the pair of liner constituting members 21 and 22, but the trunk portion 31 and One end side of the body 41 is formed as a closed end.

  Here, in this specification, the liner constituting members 21 and 22 are members constituting the resin liner 11 having a split structure, and at least one end side (part) has a hollow cylindrical shape as described above. Say things. Therefore, the shape of the liner constituent members 21 and 22 includes that the overall shape is a cylindrical shape, an annular shape, a bowl shape, a dome shape, or the like.

  FIG. 2 is an enlarged cross-sectional view around the joints 34 and 44. In FIG. 2, the reinforcing layer 12 is omitted.

  One joining portion 34 has a joining end surface 51 inclined at a predetermined angle and an extending portion 52 extending in the axial direction of the resin liner 11. The joint end surface 51 is formed so as to be chamfered inward (inverted taper shape). The extending portion 52 is connected to the distal end portion which is the outer side in the radial direction of the joining end surface 51 and is formed in a substantially cylindrical shape.

  Similarly, the other joining portion 44 has a joining end surface 61 inclined at a predetermined angle and an extending portion 62 extending in the axial direction of the resin liner 11. The joining end face 61 is formed so as to be chamfered outward (tapered). The extending portion 62 is connected to the distal end portion that is the radially inner side of the joining end surface 61 and is formed in a substantially cylindrical shape.

  In the state in which the liner constituting members 21 and 22 are abutted with each other, the one joining portion 34 and the other joining portion 44 are aligned with each other, and the joining end surfaces 51 and 61 are aligned with each other of the resin liner 11. Contact in the circumferential direction. In this state, the joint portions 34 and 44 are disposed so as to overlap in the axial direction of the resin liner 11, and the overlapped portions are in contact with each other in the circumferential direction of the resin liner 11.

  Here, the overlapping portions are one of the outer extending portion 52 and the outer peripheral surface near the joint portion 44 in contact with the inner peripheral surface, and the other is the inner extending portion 62. This is the inner peripheral surface in the vicinity of the joint 34 that is in contact with the outer peripheral surface. By providing such extended portions 52 and 62, the adhesion between the joint portions 34 and 44 can be increased in the manufacturing process of the gas container 1 described later. In addition, although the angle of both joining end surfaces 51 and 61 is arbitrary, it should just be an angle which can permeate | transmit or receive the laser from the laser torch 140 (laser irradiation apparatus).

  In the present embodiment, the liner constituting member 21 having the joint portion 34 located on the outer side in the resin liner 11 is formed of a laser transmissive thermoplastic resin. On the other hand, the liner constituting member 22 having the joint portion 44 located on the inner side in the resin liner 11 is formed of a laser-absorbing thermoplastic resin.

  The laser-transmitting thermoplastic resin only needs to be transparent to the laser so that energy necessary for laser welding reaches the bonding end surface 61 of the bonding portion 44 on the laser absorption side. Therefore, even a laser-transmitting thermoplastic resin may have a slight laser-absorbing characteristic.

  Examples of the laser-transmitting thermoplastic resin include polyethylene, polypropylene, nylon 66, and the like, and those obtained by adding a reinforcing fiber such as glass fiber or a colorant to these may be used. For example, the laser transmissive liner component 21 is formed in white, translucent or transparent.

The laser-absorbing thermoplastic resin only needs to have an absorptivity with respect to the laser and may be any one that generates heat and melts with the absorbed laser. Examples of the laser-absorbing thermoplastic resin include polyethylene, polypropylene, nylon 66, and the like, and those obtained by adding a reinforcing fiber such as glass fiber or a colorant to these may be used.
For example, when the laser-absorbing thermoplastic resin is formed of the same resin as the laser-transmitting thermoplastic resin, it is formed by adding more carbon than the laser-transmitting thermoplastic resin. Therefore, the laser-absorbing liner constituting member 22 is formed in black, for example.

  The joining end surfaces 51 and 61 of the laser transmitting joint 34 and the laser absorbing joint 44 are joined by laser welding. Laser welding is performed by irradiating a laser with a laser torch 140 from the outside of the joint portion 34 to heat and melt the resin of the joint end face 61 and heat and melt the resin of the joint end face 51 by heat transfer from the joint end face 61. Is called.

  Therefore, the laser welded portion 70 in the joint portion where the joint portions 34 and 44 are joined is a portion where both the joint end surface 61 and the joint end surface 51 are melted, and both the laser-absorbing and laser-transmitting resins are used. It is in an intertwined state.

The entire liner constituting members 21 and 22 may not be made of a laser transmitting or laser absorbing resin. For example, each of the liner constituent members 21 and 22 may partially have a laser transmitting property or a laser absorbing property, for example, only the joint portions 34 and 44 are formed of a laser transmitting or laser absorbing resin. .
Further, for example, both of the pair of liner constituting members 21 and 22 are made of a laser-transmitting resin, and the joining end face 51 (or 44) of the joining portion 34 (or 44) of one of the liner constituting members 21 (or 22). Alternatively, an absorbent having laser absorptivity may be applied to 61), or a sheet containing such an absorbent may be attached.

Here, with reference to FIG. 3 and FIG. 4, the manufacturing method of the gas container 1 is demonstrated.
First, a pair of liner constituent members 21 and 22 and two caps 3 and 3 are formed (S1). At this time, for example, one preformed base 3 is placed in the mold, a laser-transmitting thermoplastic resin is injected into the mold, and the liner constituting member 21 and the base 3 are integrally molded (insert molding). To do.)

  In addition, by a similar procedure, a laser-absorbing thermoplastic resin is injected to integrally form the liner constituting member 22 and the base 3. Thus, each liner constituent member 21 and 22 can be molded with high molding accuracy by using injection molding. Instead of injection molding, rotational molding or blow molding may be used.

  Next, the liner constituent members 21 and 22 with the base 3 are disposed in, for example, a lateral orientation in the chamber 101, the liner constituent members 21 and 22 are brought into contact with each other, and the joint portions 34 and 44 are brought into contact with each other (S2). In this state, as described above, the joint portions 34 and 44 are disposed so as to overlap in the axial direction, and the joint end surfaces 51 and 61 are in contact with each other in the circumferential direction. Thus, the resin liner 11 is in a state where the liner constituent members 21 and 22 are temporarily joined (temporary joined).

  Thereafter, a stopper (not shown) is screwed and connected to the base 3 of the liner constituent member 22 and a pipe 121 is screwed and connected to the base 3 of the liner constituent member 21 so that the inside of the temporarily bonded resin liner 11 is substantially sealed. To do. The cap 3 for screwing and connecting the plug and the pipe 121 may be reversed.

  Next, the inert gas supply device 110 connected to the chamber 101 is driven to fill the chamber 101 with an inert gas (S3). The inert gas supply device 110 includes, for example, a gas cylinder 111 that stores an inert gas, a gas pipe 112 that connects the gas cylinder 111 and the chamber 101, and an inert gas in the gas cylinder 111 provided on the gas pipe 112. And a chamber pump 113 that pumps the gas into the chamber 101.

  Examples of the inert gas include argon, nitrogen, and helium. By filling the inert gas with the inert gas supply device 110, the inside of the chamber 101 outside the resin liner 11 is set to an inert gas atmosphere. By maintaining such an inert gas atmosphere, it is possible to suppress oxidation of the joint portions 34 and 44 during laser welding in a subsequent process.

  As the next step, the negative pressure generator 120 connected to the temporarily bonded resin liner 11 is driven to depressurize the substantially sealed space of the resin liner 11 (S4). The negative pressure generator 120 includes, for example, a pipe 121 connected to the base 3 and a liner pump 122 that is provided on the pipe 121 outside the chamber 101 and depressurizes the inside of the resin liner 11. Yes.

  By driving the liner pump 122, the inside of the resin liner 11 becomes negative pressure. When the pressure in the resin liner 11 becomes lower than the pressure in the chamber 101, a pressure difference is generated between the inside and outside of the resin liner 11. This pressure difference increases the degree of adhesion between the joint portions 34 and 44. In particular, since the joint portions 34 and 44 overlap each other in the axial direction and the overlapping portions are in contact with each other, the adhesion between the joint portions 34 and 44 is further increased.

  Here, prior to laser welding, based on the detection result by the concentration sensor 131 provided in the chamber 101, it is confirmed whether or not the inside of the chamber 101 has reached a predetermined inert gas concentration (S5). When the predetermined concentration is reached, the driving of the inert gas supply device 110 may be stopped.

  Further, based on the detection result by the pressure sensor 132 provided in the chamber 101 and the detection result by the pressure sensor 133 provided in the pipe 121, whether or not the differential pressure level inside and outside the resin liner 11 has reached a predetermined value. Confirm (S5).

  When the differential pressure level reaches a predetermined value, the drive of the negative pressure generator 120 is stopped and a shut-off valve (not shown) provided on the pipe 121 may be closed. However, the driving of the negative pressure generator 120 is continued (controlled) during laser welding in the subsequent process so that the pressure difference between the inside and outside of the resin liner 11 is maintained at a predetermined level even during laser welding. Good. The arrangement positions of the two pressure sensors 132 and 133 are not limited to the above.

  As the next step, the laser torch 140 is driven to join the joint portions 34 and 44 of the resin liner 11 by laser welding (S6). The laser torch 140 irradiates the contact end surfaces 51 and 61 in contact with each other from the outside of the laser-transmitting joint 34. The irradiated laser passes through the laser-transmitting bonding portion 34 and reaches the laser-absorbing bonding end surface 61, and the resin on the bonding end surface 61 is heated and melted. Further, the heat transfer from the joining end face 61 heats and melts the resin of the laser transmitting joining end face 51. Then, the melted resin is cooled and solidified to form a laser welding portion 70 that integrally joins the joint portions 34 and 44 to each other.

  Here, at the time of laser welding (S6), in synchronization with the laser irradiation by the laser torch 140, a rotating device (not shown) is driven to rotate the temporarily bonded resin liner 11 about its axis. By doing so, the laser-absorbing bonding end surface 61 is sequentially heated and melted in the circumferential direction, and the laser-absorbing bonding end surface 61 is sequentially heated and melted in the circumferential direction by this heat transfer. Therefore, the laser welding part 70 which joined the joining end surfaces 51 and 61 integrally over the circumferential direction by rotating the resin liner 11 at least 1 time, maintaining the substantially cylindrical shape of the resin liner 11 is provided. It is formed.

  Instead of rotating the resin liner 11 directly, the laser torch 140 may be rotated directly around the resin liner 11. Alternatively, both the resin liner 11 and the laser torch 140 may be rotated in the same direction or in the opposite direction. However, as described above, rotating the resin liner 11 can be simplified in terms of positioning of the resin liner 11 and device configuration.

  In laser welding as described above, the area of the portion for laser welding can be increased by devising the shapes of the two joint portions 34 and 44. Specifically, as shown in FIG. 2, the joining end surfaces 51 and 61 are inclined with respect to the axial direction of the resin liner 11, so that the joining end surfaces 51 and 61 are orthogonal to the axial direction of the resin liner 11. Compared to the case, the contact area between the joining end faces 51 and 61 can be increased. Thereby, the laser welding part 70 can be made large enough, and the joining strength of the resin liner 11, etc. can be improved suitably.

  Further, since the laser welding is performed in a state where a differential pressure is generated inside and outside the resin liner 11, the joining end faces 51 and 61 are joined to each other in a state where the adhesion degree between the joining portions 34 and 44 is increased. Thereby, since joining end surface 51,61 is favorably joined by laser welding, the intensity | strength and airtightness of the resin liner 11 can be ensured appropriately.

  In addition, a pressure jig for bringing the joint portions 34 and 44 into close contact with each other can be simplified or unnecessary. Furthermore, the joint structure between the overlapped joint portions 34 and 44 can effectively cause the adhesion force generated by the differential pressure to act on the joint portions 34 and 44, thereby improving the laser welding reaction. Can be advanced.

  Furthermore, since the laser welding process is performed in an inert gas atmosphere, oxidation of the joint portions 34 and 44 is suppressed. As a result, it is possible to avoid charring due to local oxidation between the joint portions 34 and 44, laser transmission defects and pinholes, and the like, which join the joint end surfaces 51 and 61 well and appropriately. be able to. When the laser welding is completed, the resin liner 11 is changed from the temporarily joined state to the fully joined state (that is, the completely joined state), and the storage space 5 is formed in the hollow interior.

  The laser emitted from the laser torch 140 can be a semiconductor laser or the like, but is not limited to this. Considering the properties including the thickness of the resin of the laser-transmitting liner constituting member 21, etc. It is selected appropriately. In the laser welding process, various conditions such as the laser output (irradiation amount) and the rotation speed of the resin liner 11 may be set as appropriate according to the properties of the liner constituent members 21 and 22.

  After completion of laser welding, the inside of the chamber 101 and the resin liner 11 are returned to atmospheric pressure (S7). Next, the projection at the joint portion on the outer peripheral surface of the resin liner 11 is cut (S8). The projecting portion includes a peripheral portion including the extending portion 52 of the laser-transmitting joint portion 34, and is formed so as to project over the circumferential direction of the resin liner 11 and outward in the radial direction of the resin liner 11. (See FIG. 2).

  In the cutting process of S8, the projecting portion is cut in the circumferential direction so that the joint portion on the outer peripheral surface of the resin liner 11 is flush with (substantially the same outer diameter). Finally, the reinforcing layer 12 is formed on the outer surface of the resin liner 11 by a filament winding method or the like (S9), whereby the gas container 1 is manufactured.

  As described above, according to the present embodiment, since laser welding is used for joining the liner constituting member 21 and the liner constituting member 22, the resin liner 11 can be manufactured in a short time and at low cost. Thereby, productivity of the gas container 1 can be improved as a whole. Further, as described above, since laser welding is performed in an inert gas atmosphere and the degree of adhesion between the joint portions 34 and 44 is increased by applying a differential pressure, bonding failure can be suppressed. The resin liner 11 with high bonding accuracy can be manufactured.

  Depending on the shape of the joint portions 34, 44, the protrusion at the joint portion on the outer peripheral surface of the resin liner 11 may be formed by both liner constituent members 21, 22. In that case, what is necessary is just to grind both the outer peripheral surfaces of the two liner structural members 21 and 22 in the cutting process of S8.

Second Embodiment
Next, with reference to FIG. 5 and FIG. 6, the manufacturing method of the gas container 1 which concerns on 2nd Embodiment is demonstrated centering on difference. The difference from the first embodiment is that a heated gas supply device 160 is provided as a differential pressure generating device instead of the negative pressure generating device 120, and accordingly, S4 of the manufacturing process is changed to S4 ′. .

  The heated gas supply device 160 can be configured in the same manner as the inert gas supply device 110. For example, the heated gas supply device 160 is provided on a gas cylinder 161 that stores an inert gas, a pipe 162 that connects the gas cylinder 161 to the die 3 of the resin liner 11 in a temporarily bonded state, and a pipe 162 outside the chamber 101. And a liner pump 163 that pumps the inert gas in the gas cylinder 161 into the resin liner 11.

  The inert gas supplied into the resin liner 11 may be a different type of gas from the inert gas supplied into the chamber 101, or the same type of gas. When the same kind of gas is used, the gas cylinder 161 may be omitted and the gas cylinder 111 for the chamber 101 may be shared by the heated gas supply device 160.

  The liner pump 163 includes a heater (not shown) that heats the inert gas from the gas cylinder 161. Therefore, when the liner pump 163 is driven, the heated inert gas is supplied into the resin liner 11. Needless to say, the liner pump 163 may not be provided with a heater. For example, the pipe 162 may be provided with a heating means such as a heater.

  S4 ′ of the manufacturing process is performed by driving the heated gas supply device 160 connected to the temporarily bonded resin liner 11 to supply the heated inert gas to the substantially sealed space of the resin liner 11. . When the resin liner 11 is filled with a predetermined amount of inert gas, the internal pressure of the resin liner 11 increases. When the internal pressure of the resin liner 11 becomes higher than the internal pressure of the chamber 101 (that is, the external pressure of the resin liner 11), a pressure difference is generated between the inside and outside of the resin liner 11.

  Therefore, also in this embodiment, a pressure difference can be generated inside and outside the resin liner 11. Thereby, in the laser welding process (S6) which becomes a post process, the joining parts 34 and 44 can be laser-welded in a state where the adhesion degree between the joining parts 34 and 44 is increased. It is preferable to control the driving of the liner pump 163 so that the pressure difference between the inside and outside of the resin liner 11 is maintained at a predetermined level even during laser welding.

<Third Embodiment>
Next, with reference to FIG. 7 and FIG. 8, the manufacturing method of the gas container 1 which concerns on 3rd Embodiment is demonstrated centering on difference. The difference from the first embodiment is that a vacuum generator 170 is provided instead of the inert gas supply device 110, and a heated air supply device 180 is provided as a differential pressure generator instead of the negative pressure generator 120. That is, along with these, S3 to S5 in the manufacturing process are changed to S3 ″ to S5 ″.

  The vacuum generator 170 includes, for example, a vacuum pump 171 that sucks air in the chamber 101, a buffer tank 172 that temporarily stores air sucked by the vacuum pump 171, and air that connects the chamber 101 and the buffer tank 172. And a pipe 173.

  By driving the vacuum pump 171 on the air pipe 173, the chamber 101 can be set in a vacuum state. Note that a sensor for detecting the degree of vacuum in the chamber 101 may be provided in the air pipe 173 on the upstream side (chamber 101 side) of the vacuum pump 171 and the driving of the vacuum pump 171 may be controlled based on the detection result of the sensor.

  The heated air supply device 180 heats the air in the chamber 101 sucked by the vacuum generator 170 and supplies it to the resin liner 11. For example, the warming air supply device 180 is provided with a liner pump 181 that pumps air stored in the buffer tank 172 into the resin liner 11 and a liner pump 181, and the base 3 and the buffer of the resin liner 11. And a pipe 182 for joining the tank 172.

  The liner pump 181 has a built-in oil diffusion heater (not shown) for heating the air from the buffer tank 172. Therefore, when the liner pump 181 is driven, the air heated by the heater is supplied into the resin liner 11.

  Instead of the configuration in which a heater is provided in the liner pump 181, for example, a heating unit such as a heater may be provided in the pipe 182 or the buffer tank 172. Further, the heated air supply device 180 can be configured, for example, as the heated gas supply device 160 of the second embodiment, but by injecting air into the resin liner 11 evacuated from the chamber 101. , Can increase the overall efficiency on the system.

  In S3 ″ of the manufacturing process of the present embodiment, evacuation is performed in the chamber 101 in which the temporarily bonded resin liner 11 is installed. This is performed by driving the vacuum pump 171 for a predetermined time, whereby the chamber 101 is evacuated.

  The next step S <b> 4 ″ is performed by driving the liner pump 181 and supplying the heated air to the substantially sealed space of the resin liner 11. When a predetermined amount of warming air is filled into the resin liner 11, the internal pressure of the resin liner 11 increases.

  When the internal pressure of the resin liner 11 becomes higher than the internal pressure of the chamber 101 (that is, the external pressure of the resin liner 11), a pressure difference is generated between the inside and outside of the resin liner 11. Whether or not this pressure difference has reached a predetermined level (optimal differential pressure level) is confirmed by, for example, the pressure sensor 132 in the chamber 101 and the pressure sensor 133 on the pipe 182 (S5 ″), and the next laser. The process proceeds to the welding step (S6).

  Therefore, even in the present embodiment, a pressure difference can be generated inside and outside the resin liner 11, so that in the laser welding step (S 6), which is a subsequent step, the degree of adhesion between the joint portions 34 and 44 is increased. The joining portions 34 and 44 can be laser-welded. Moreover, since laser welding can be performed under a vacuum state, the joining end surfaces 51 and 61 can be favorably and appropriately joined together by appropriately suppressing the oxidation of the joining portions 34 and 44.

  Furthermore, a useful point compared with the above embodiments is that impurities that can adhere to the outer surface of the resin liner 11 and the like can be sucked (removed) together with air when the chamber 101 is evacuated. . Further, it is useful that the air tightness of the resin liner 11 can be immediately confirmed after the completion of laser welding (S6). For example, heated air is supplied to the inside of the resin liner 11 after the laser welding is completed, and a pressure change inside and outside the resin liner 11 is detected by the pressure sensor 132, thereby confirming the airtightness after the welding. be able to.

  In the description of the first to third embodiments described above, the pressure inside the resin liner 11 is adjusted to apply a pressure difference to the inside and outside of the resin liner 11. Of course, instead of this configuration, by adjusting the pressure outside the resin liner 11, that is, the pressure inside the chamber 101 between the outer wall of the resin liner 11 and the inner wall of the chamber 101, a pressure difference is created between the inside and outside of the resin liner 11. You may make it provide. Further, both the internal pressure and the external pressure of the resin liner 11 may be adjusted.

<Fourth embodiment>
Next, with reference to FIG. 9 and FIG. 10, it demonstrates centering around difference about the manufacturing method of the gas container 1 which concerns on 4th Embodiment. The main difference from the first embodiment is that an annealing process (S14) of the resin liner 11 in a temporarily bonded state is performed prior to the laser welding process (S15). In addition, since S11 and S12 of a manufacturing process are the same as S1 and S2 of 1st Embodiment, and S15-S18 are the same as S6-S9 of 1st Embodiment, detailed description about these is abbreviate | omitted.

  In S13 of the manufacturing process, the inside of the chamber 101 in which the temporarily bonded resin liner 11 is provided is evacuated. This is performed, for example, by driving the vacuum pump 191 of the vacuum generator 190 and sucking the air in the chamber 101 through the air pipe 192 connected to the chamber 101. The vacuum generator 190 can be configured similarly to the vacuum generator 170 of the third embodiment.

  In the annealing process (annealing) of S14 in the next step, first, the interior of the chamber 101 is heated to heat the resin liner 11 to a predetermined temperature. Then, after maintaining this heating state for a predetermined time, the inside of the chamber 101 is cooled and the resin liner 11 is cooled.

  Although the residual stress of the resin liner 11 is removed by this annealing treatment, the liner constituent members 21 and 22 self-shrink at this time, so that the adhesion between the joint portions 34 and 44 increases. Thereby, in the laser welding process (S15) after completion of the annealing treatment, the joining portions 34 and 44 in a state where the adhesion degree is increased can be laser-welded.

  Therefore, also according to the present embodiment, the joining portions 34 and 44 can be favorably and appropriately joined by laser welding. In addition, since the annealing process is performed in a vacuum, the laser welding process can be directly performed after the annealing process is completed.

  Also in the present embodiment, the above-described differential pressure generator (the negative pressure generator 120 of the first embodiment, the heated gas supply device 160 of the second embodiment, and the heated air supply device 180 of the third embodiment). May be used supplementarily. By doing so, the degree of adhesion between the joint portions 34 and 44 can be further increased. In addition, since the degree of adhesion between the joint portions 34 and 44 is increased by the annealing treatment, the components of the differential pressure generating device (for example, the liner pumps 122, 163, and 181) can be reduced in size and simplified.

<Fifth Embodiment>
Next, with reference to FIG. 11, it demonstrates centering around difference about the gas container 1 which concerns on 5th Embodiment. The difference from the first embodiment is that the resin liner 11 of the gas container 1 is composed of three liner constituent members 201, 202, and 203. In FIG. 11, the reinforcing layer 12 is omitted.

  The resin liner 11 is configured by joining three liner constituting members 201, 202, and 203 divided in three in the longitudinal direction by laser welding. The two liner constituting members 201 and 202 located at both ends are formed in a bowl shape as a whole. The liner constituting member 203 located at the center is formed in a cylindrical or annular shape as a whole. The two liner constituting members 201 and 202 at both ends are integrally formed with the base 3 by, for example, injection molding. The central liner constituting member 203 is formed by, for example, injection molding.

  Each of the two liner constituent members 201 and 202 at both ends has joint portions 213 and 223 on the side opposite to the caps 3 and 3 in addition to the return portions 211 and 221 and the communication portions 212 and 222. The central liner constituting member 203 has joint portions 231 and 232 on both end sides opened in the axial direction.

  In addition, about these junction parts (213,223,231,232), it comprised simply by the end surface orthogonal to an axial direction, but the irradiation property of a laser and the adhesiveness by a differential pressure are made like 1st Embodiment. It is preferable to consider the configuration.

  These joint portions (213, 223, 231 and 232) have laser transmission characteristics or laser absorption characteristics. For example, the two liner constituent members 201 and 202 at both ends are formed of a laser-transmitting thermoplastic resin, and the central liner constituent member 203 is formed of a laser-absorbing thermoplastic resin. Of course, this may be reversed, and each of the liner constituting members 201, 202, 203 may partially have a laser transmitting property or a laser absorbing property. In the resin liner 11, the joint portions 213 and 231 are joined to each other by laser welding, and the joint portions 223 and 232 are joined to each other by laser welding.

  The manufacturing method of each embodiment mentioned above can be applied to the manufacturing method of the gas container 1 of this embodiment. Here, the case where the three liner constituent members 201, 202, 203 are simultaneously joined by laser welding will be briefly described.

  First, three liner constituent members 201, 202, 203 including a liner constituent member (201, 202) with a base 3 are formed, and these are arranged in the chamber 101 to join the joints 213, 231 and the joints 223. 232 are brought into contact with each other to form the resin liner 11 in a temporarily bonded state.

  Next, for example, the inside of the chamber 101 is placed in an inert gas atmosphere or in a vacuum state, and a resin liner is formed by a differential pressure generator (for example, the negative pressure generator 120, the heated gas supply device 160, and the heated air supply device 180 of the above embodiment). The substantially sealed space 11 is depressurized or pressurized, and a predetermined pressure difference is set inside and outside the resin liner 11.

  Next, while rotating the temporarily bonded resin liner 11 around its axis or rotating the two laser torches 140 around the resin liner 11, the bonding portions 213 and 231 and the bonding portions 223 and 232 are lasered. It joins over the circumferential direction by welding. As a result, the three liner constituting members 201, 202, 203 are integrally joined, and the resin liner 11 in the final joined state is manufactured. Then, the gas container 1 is manufactured through a predetermined process (for example, S7 to S9 in the first embodiment).

  Therefore, even if the resin liner 11 is constituted by the three liner constituting members 201, 202, and 203 as in the present embodiment, the highly productive gas container 1 can be manufactured as in the above embodiment.

  In addition, although the example which performed the process of temporary joining, laser welding, etc. simultaneously about three liner structural members 201,202,203 was demonstrated, of course, you may perform these processes separately. Moreover, although the case where there were three liner structural members was demonstrated, four or more are the same. That is, the present invention can be applied to the resin liner 11 in which a plurality of liner constituent members arranged in the axial direction are joined.

<Other embodiments>
Various modifications can be applied to the gas container 1 of the present invention described above. For example, an engagement structure that engages so as to bring the joint portions into close contact may be provided in the vicinity of the laser welded portion between the joint portion of one liner constituent member and the joint portion of another liner constituent member. An example of the engagement structure is a screwing structure. An example in which this screwing structure is applied to the resin liner 11 having a two-part structure shown in the first embodiment will be briefly described.

  For example, as a screwing structure, a screw is engraved on the outer peripheral surface of the extending portion 62 of the joint portion 44 shown in FIG. 2, and the inner peripheral surface of the body portion 31 near the joint portion 34 is correspondingly formed. Engrave female threads. By doing so, prior to laser welding of the joint portions 34 and 44, the joint end surfaces 51 and 61 are brought into contact with each other and the male screw and the female screw are screwed together to constitute the resin liner 11 in a temporarily joined state. be able to.

  Thereby, in the case of laser welding, it can be stuck so that bonding parts 34 and 44 may not leave, and the joining accuracy of laser welding can be raised further. The threaded portion of the external screw / female screw may also be laser welded. Further, this type of engagement structure is not limited to a screwed structure, and may be, for example, a snap fit or a press fit.

  The laser welding described for the gas container 1 can be applied not only to the resin liner 11 but also to various resin molded products such as automobile parts and piping parts. For example, even when the intake manifold is composed of a plurality of resin molding materials and the resin molding materials are joined together by laser welding, the structure of the joints described above, the application of a pressure difference during laser welding, Application of an inert gas atmosphere or a vacuum state can increase the bonding accuracy.

It is sectional drawing which shows the structure of the gas container which concerns on 1st Embodiment. It is sectional drawing which expands and shows the junction part of the gas container which concerns on 1st Embodiment. It is explanatory drawing explaining the manufacturing method of the gas container which concerns on 1st Embodiment. It is a flowchart which shows the process of the manufacturing method of the gas container which concerns on 1st Embodiment. It is explanatory drawing explaining the manufacturing method of the gas container which concerns on 2nd Embodiment. It is a flowchart which shows the process of the manufacturing method of the gas container which concerns on 2nd Embodiment. It is explanatory drawing explaining the manufacturing method of the gas container which concerns on 3rd Embodiment. It is a flowchart which shows the process of the manufacturing method of the gas container which concerns on 3rd Embodiment. It is explanatory drawing explaining the manufacturing method of the gas container which concerns on 4th Embodiment. It is a flowchart which shows the process of the manufacturing method of the gas container which concerns on 4th Embodiment. It is sectional drawing which shows the structure of the gas container which concerns on 5th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Gas container, 11 Resin liner, 12 Reinforcement layer, 21 Liner structural member, 22 Liner structural member, 33 Communication part, 34 Joint part, 43 Communication part, 44 Joint part, 70 Laser welding part, 140 Laser torch, 201 Liner structural member 202 liner constituent member, 203 liner constituent member, 213 joint portion, 223 joint portion, 231 joint portion, 232 joint portion

Claims (19)

A resin liner formed by joining a plurality of liner components having at least a hollow cylindrical shape;
A reinforcing layer disposed on the outer periphery of the resin liner;
A gas container comprising:
The gas containers in which the joint portions of the plurality of liner constituent members are joined to each other by laser welding. A resin liner formed by joining a plurality of liner components having at least a hollow cylindrical shape;
A reinforcing layer disposed on the outer periphery of the resin liner;
A gas container comprising:
The gas container which has the laser welding part which the junction part where the junction part of one liner structural member, and the junction part of the other liner structural member joined, joined these joint parts mutually by laser welding.   The gas container according to claim 1 or 2, wherein the joint portions are joined to each other by laser welding along a circumferential direction of the resin liner.   4. The joint part of one liner constituent member joined to each other is made of a laser transmitting member, and the joint part of the other liner constituent member is made of a laser absorbing member. A gas container according to 1.   The gas container according to any one of claims 1 to 3, wherein one liner constituent member joined to each other is made of a laser transmitting member, and the other liner constituent member is made of a laser absorbing member.   6. The joint according to claim 4, wherein the joining portion made of the laser transmissive member is located outside the resin liner, and the joining portion made of the laser absorbing member is located inside the resin liner. Gas container.   At least one of the plurality of liner constituting members has a communication portion for communicating the hollow interior and the outside of the resin liner on the opposite side to the joint portion to be joined to the other liner constituting member. The gas container according to any one of claims 1 to 6. A method for producing a gas container having a resin liner constituted by joining a plurality of liner components having a hollow cylindrical shape at least partially,
A first step of configuring a joint portion of one liner constituent member to be joined to each other with a laser transmitting member and a joint portion of the other liner constituent member with a laser absorbing member;
After the first step, a second step of bringing the joint portions of the liner constituent members to be joined together into contact with each other;
After the second step, a third step of irradiating the laser from the joint portion made of the laser-transmissive member and joining the joint portions in contact with each other by laser welding;
The manufacturing method of the gas container which has. The second step is performed by bringing the laser-transmitting bonding portion into contact with the laser-absorbing bonding portion from the outside,
The method of manufacturing a gas container according to claim 8, wherein the third step is performed by irradiating a laser from the laser-transmitting joint side with a laser irradiation device disposed outside the liner constituting member.   10. The method for manufacturing a gas container according to claim 8, wherein the third step includes irradiating a laser in a state where a pressure difference is applied to the inside and outside of the two liner constituent members to be joined to each other.   The production of the gas container according to claim 10, wherein the application of the pressure difference in the third step is performed by adjusting at least one of an internal pressure and an external pressure of two liner constituent members to be joined to each other. Method.   12. The gas container according to claim 11, wherein the application of the pressure difference in the third step is performed by setting the inside of two liner constituent members to be joined to each other substantially in a sealed state and reducing or pressurizing the sealed space. Manufacturing method.   The application of the pressure difference in the third step is performed by depressurizing or pressurizing the sealed space via a communication portion provided in at least one of two liner constituent members to be joined to each other. The manufacturing method of the gas container of description.   The second step is performed by arranging joint portions of two liner constituent members to be joined to each other so as to overlap each other in the axial direction of the liner constituent members, and bringing the overlapped portions into contact with each other. Item 14. The method for producing a gas container according to any one of Items 8 to 13.   15. The method according to any one of claims 8 to 14, further comprising a step of performing an annealing process between the second step and the third step in a state where the joint portions of the two liner constituent members to be joined to each other are in contact with each other. A method for producing a gas container according to claim 1.   In the third step, the two joining members to be joined to each other are rotated relative to the laser irradiation apparatus, and the joining portions in the contact state are laser-welded in the circumferential direction of the liner constituting member. The method for producing a gas container according to any one of claims 8 to 15, wherein   The method of manufacturing a gas container according to any one of claims 8 to 16, wherein the third step is performed in a low oxygen atmosphere.   18. The first step is performed by configuring one liner constituent member to be bonded to each other with a laser transmitting member and configuring the other liner constituent member with a laser absorbing member. The manufacturing method of the gas container as described in any one of these.   After the third step, the method further comprises a step of cutting at least one outer peripheral surface of the two liner constituent members such that a joint between the outer peripheral surfaces of the two liner constituent members joined by laser welding is flush with each other. The method for manufacturing a gas container according to any one of claims 8 to 18.

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