air bag

Abstract

This invention provides an air bag that allows for the simple implementation of a two-tiered stacked bag structure. [Solution] The air bag 30 comprises a first bag portion 40 having a first air chamber 41 that expands and contracts and a first joint portion 42 that joins two sheet materials 31 and 32 so as to partition the first air chamber 41; a second bag portion 50 having a second air chamber 51 that expands and contracts and a second joint portion 52 that joins two sheet materials 31 and 32 so as to partition the second air chamber 51; a bending portion 60 having a connecting channel 70 that connects the first air chamber 41 and the second air chamber 51 and a third joint portion 61 that joins two sheet materials 31 and 32 so as to partition the connecting channel 70, and a bending portion 60 that bends so as to overlap the first air chamber 41 and the second air chamber 51. The bending portion 60 is provided in the intermediate channel 73 of the connecting channel 70 and further has an intermediate joint portion 62 that has higher bending rigidity than the sheet materials 31 and 32.

Description

Technical Field

[0001] The present invention relates to an airbag.

Background Art

[0002] Patent Document 1 describes a massage device mounted on a vehicle seat. The massage device includes an airbag that expands by air supply and contracts by exhaust, a pump that pumps air, a tube that connects the airbag and the pump, and a valve device that switches the air supply and exhaust to the airbag.

[0003] In the massage device, the airbag has a first bag portion and a second bag portion laminated on the first bag portion. The airbag is incorporated in the seat back and seat cushion of the vehicle seat, etc. And the massage device massages the user sitting on the seat by supplying air to the airbag. When air is supplied to the airbag, the two laminated bag portions expand, so that the force of the airbag pushing the user can be increased.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The airbag as described above is configured by welding a first bag portion formed by welding two sheet members and a second bag portion formed by welding another two sheet members. Specifically, the first bag portion and the second bag portion are welded by welding one sheet member constituting the first bag portion and one sheet member constituting the second bag portion. In this regard, it is desired to simply realize a configuration in which the bag portions are laminated in two stages.

Means for Solving the Problems

[0006] An air bag that solves the above problems is an air bag comprising two sheet materials, comprising: a first bag portion having a first air chamber that expands when air is supplied and contracts when exhausted, and a first joint portion that joins the two sheet materials so as to partition the first air chamber; a second bag portion having a second air chamber that expands when air is supplied and contracts when exhausted, and a second joint portion that joins the two sheet materials so as to partition the second air chamber; a bent portion having a connecting channel that connects the first air chamber and the second air chamber, and a third joint portion that joins the two sheet materials so as to partition the connecting channel, the bent portion being bent so as to overlap the first air chamber and the second air chamber, wherein the connecting channel has a first channel that connects to the first air chamber, a second channel that connects to the second air chamber, and an intermediate channel that is wider than both the first channel and the second channel and connects the first channel and the second channel, and the bent portion further has a rigid portion provided in the intermediate channel that has higher bending rigidity than the sheet materials. [Effects of the Invention]

[0007] The air bag can be easily constructed by stacking the bag sections in two layers. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view of a seat equipped with a pneumatic system. [Figure 2] Figure 2 is a front view of the air bag described above. [Figure 3] Figure 3 is a front view of the air bag in its deflated state. [Figure 4] Figure 4 is a cross-sectional view of the air bag in its contracted state. [Figure 5] Figure 5 is a cross-sectional view of the air bag in its inflated state. [Figure 6] Figure 6 is an enlarged plan view of the air bag connection channel in the first modified example. [Figure 7]Figure 7 is an enlarged plan view of the air bag connection channel in the second modified example. [Figure 8] Figure 8 is an enlarged plan view of the air bag connection channel in the third modification example. [Modes for carrying out the invention]

[0009] <Configuration of this embodiment> As shown in Figure 1, the seat 10 comprises a seat cushion 11, a seat back 12, and a pneumatic system 20.

[0010] The seat 10 is a vehicle seat, for example, used in the driver's seat, passenger seat, and rear seats of a vehicle. In other embodiments, the seat 10 may be a massage seat used in a facility or the like. The seat cushion 11 is mainly the part that supports the buttocks and thighs of the user sitting on the seat 10. The seat back 12 is mainly the part that supports the lower back and back of the user sitting on the seat 10.

[0011] <Pneumatic System 20> The pneumatic system 20 comprises a plurality of air bags 30, a support pad 80, a pump 91, a valve device 92, and piping 93. Preferably, the majority of the pneumatic system 20 is housed inside the seat 10.

[0012] <Air bag 30> Multiple air bladders 30 are built into the seat back 12. In the example shown in Figure 1, two air bladders 30 are arranged in the width direction of the seat back 12, and three air bladders 30 are arranged in the vertical direction of the seat back 12. In other embodiments, the number of air bladders 30 built into the seat back 12 can be changed as appropriate. Also, the arrangement of the air bladders 30 built into the seat back 12 can be changed as appropriate.

[0013] As shown in FIG. 2, the airbag 30 includes two sheet materials 31 and 32 and a connecting pipe 33. The airbag 30 also includes a first bag portion 40, a second bag portion 50, and a bending portion 60. In the first embodiment, the first bag portion 40, the second bag portion 50, and the bending portion 60 are formed by joining the two sheet materials 31 and 32. In the following description, the state of the airbag 30 shown in FIG. 2 is also referred to as the "deployed state".

[0014] The two sheet materials 31 and 32 are made of a thermoplastic resin having appropriate elasticity such as polyethylene. The two sheet materials 31 and 32 have the same shape. The two sheet materials 31 and 32 overlap with their thickness directions aligned. In the following description, the direction in which the two sheet materials 31 and 32 overlap in the thickness direction is also referred to as the "lamination direction".

[0015] The first bag portion 40 has a first air chamber 41, a first joint portion 42, a first connection port 43, and a communication port 44. When viewed from the lamination direction, the first air chamber 41 has a pentagonal shape. In other embodiments, the first air chamber 41 may have other polygonal shapes or a circular shape when viewed from the lamination direction. The first air chamber 41 expands by air supply and contracts by air exhaust. The first joint portion 42 joins the two sheet materials 31 and 32 so as to partition the first air chamber 41. In this regard, the first joint portion 42 also has a pentagonal shape similar to the first air chamber 41. The first connection port 43 and the communication port 44 open the first air chamber 41 to the outside of the first air chamber 41. Therefore, the two sheet materials 31 and 32 are not joined at the portions where the first connection port 43 and the communication port 44 are provided. In other words, the first joint portion 42 is interrupted at the portions where the first connection port 43 and the communication port 44 are provided. The first connection port 43 and the communication port 44 are located at the portions that form the vertices of the pentagonal first joint portion 42.

[0016] The second bag portion 50 has a second air chamber 51, a second joint portion 52, and a second connection port 53. The second air chamber 51 is pentagonal when viewed in the stacking direction. In other embodiments, the second air chamber 51 may have other polygonal shapes or a circular shape when viewed in the stacking direction. The second air chamber 51 expands by air supply and contracts by air exhaust. The second joint portion 52 joins two sheet materials 31, 32 so as to partition the second air chamber 51. In this regard, the second joint portion 52 is also pentagonal like the second air chamber 51. The second connection port 53 opens the second air chamber 51 to the outside of the second air chamber 51. Therefore, the two sheet materials 31, 32 are not joined at the portion where the second connection port 53 is provided. In other words, the second joint portion 52 is interrupted at the portion where the second connection port 53 is provided. The second connection port 53 is located at a portion constituting the vertex of the pentagonal second joint portion 52.

[0017] The second bag portion 50 has a configuration corresponding to the first bag portion 40. In the present embodiment, the second air chamber 51 of the second bag portion 50 has the same shape as the first air chamber 41 of the first bag portion 40. In other embodiments, the second air chamber 51 of the second bag portion 50 may have a shape different from the first air chamber 41 of the first bag portion 40. For example, the second air chamber 51 of the second bag portion 50 may have a different size from the first air chamber 41 of the first bag portion 40.

[0018] The bent portion 60 has a connection flow path 70, a third joint portion 61, and an intermediate joint portion 62. The connection flow path 70 extends linearly. The connection flow path 70 has a shape symmetric with respect to the longitudinal direction of the connection flow path 70. The connection flow path 70 has a first flow path 71, a second flow path 72, and an intermediate flow path 73. In the following description, the direction orthogonal to both the longitudinal direction and the stacking direction of the connection flow path 70 is referred to as the width direction, and the length in the width direction of the connection flow path 70 is referred to as the width. Note that the longitudinal direction of the connection flow path 70 can also be referred to as the direction in which air flows in the connection flow path 70.

[0019] The width of the first channel 71 is constant with respect to the longitudinal direction of the connecting channel 70. The first channel 71 is connected to the first connection port 43 of the first bag section 40. Thus, the first channel 71 is connected to the first air chamber 41 of the first bag section 40. Similarly, the width of the second channel 72 is constant with respect to the longitudinal direction of the connecting channel 70. The second channel 72 is connected to the second connection port 53 of the second bag section 50. Thus, the second channel 72 is connected to the second air chamber 51 of the second bag section 50.

[0020] The intermediate channel 73 connects the first channel 71 and the second channel 72. The intermediate channel 73 is wider than both the first channel 71 and the second channel 72. The intermediate channel 73 includes a first section 731, a second section 732, and an intermediate section 733. The first section 731 is connected to the first channel 71. The width of the first section 731 gradually narrows in the longitudinal direction of the connecting channel 70 towards the first channel 71. The second section 732 is connected to the second channel 72. The width of the second section 732 gradually narrows in the longitudinal direction of the connecting channel 70 towards the second channel 72. The intermediate section 733 connects the first section 731 and the second section 732. The width of the intermediate section 733 is constant in the longitudinal direction of the connecting channel 70. The intermediate section 733 is wider than both the first section 731 and the second section 732.

[0021] Here, the width of the intermediate channel 73 is the distance in the width direction between the third joint 61 that divides the intermediate channel 73. Also, the widths of the first part 731, the second part 732, and the intermediate part 733 are the distances in the width direction between the third joint 61 that divides the first part 731, the second part 732, and the intermediate part 733. In other words, the widths of the intermediate channel 73, the first part 731, the second part 732, and the intermediate part 733 are the widths without considering the intermediate joint 62.

[0022] In this way, the connecting channel 70 connects the first air chamber 41 and the second air chamber 51. As a result, air can flow from one of the first air chamber 41 to the other.

[0023] The third joint 61 defines the connecting channel 70. The third joint 61 is connected to the first joint 42 and the second joint 52. The intermediate joint 62 is provided in the intermediate channel 73. The intermediate joint 62 has an elliptical shape. In the front view shown in Figure 2, the longitudinal direction of the intermediate joint 62 is the longitudinal direction of the connecting channel 70, and the short direction of the intermediate joint 62 is the width direction of the connecting channel 70. Both ends of the intermediate joint 62 in the longitudinal direction are tapered. That is, the width of the intermediate joint 62 gradually decreases as it approaches the first channel 71 and gradually decreases as it approaches the second channel 72. In the longitudinal direction of the connecting channel 70, the length of the intermediate joint 62 is longer than the length of the intermediate section 733 of the intermediate channel 73. In this respect, the intermediate joint 62 extends across the first section 731, the second section 732 and the intermediate section 733 of the intermediate channel 73. The intermediate joint 62 also joins the central parts of the portions of the two sheet materials 31 and 32 that constitute the intermediate channel 73. Therefore, in the intermediate flow path 73, the portion through which air flows is divided in the width direction. The bending stiffness of the intermediate joint 62 is higher than the bending stiffness of the portion of the sheet material 31 that constitutes the intermediate flow path 73. In this respect, the intermediate joint 62 corresponds to a "rigid part". Here, bending stiffness is an indicator of how resistant a member is to bending deformation. More specifically, bending stiffness is the product of the second moment of area and Young's modulus of the member.

[0024] In the connecting channel 70, the width of the intermediate channel 73 where the intermediate joint 62 is provided is greater than or equal to the width of the first channel 71 where the intermediate joint 62 is not provided, and also greater than or equal to the width of the second channel 72 where the intermediate joint 62 is not provided. Therefore, even when the connecting channel 70 is provided with the intermediate joint 62, the cross-sectional area of ​​the connecting channel 70 is ensured. In other words, the provision of the intermediate joint 62 in the connecting channel 70 does not significantly obstruct the airflow from one of the first air chambers 41 and the second air chamber 51 to the other.

[0025] In the first embodiment, the first joint 42, second joint 52, third joint 61, and intermediate joint 62 are formed by high-frequency welding of two sheet materials 31 and 32. In other embodiments, the first joint 42, second joint 52, third joint 61, and intermediate joint 62 may be formed by heat welding or laser welding of two sheet materials 31 and 32. Alternatively, the first joint 42, second joint 52, third joint 61, and intermediate joint 62 may be formed by bonding two sheet materials 31 and 32 with an adhesive or the like.

[0026] In the first embodiment, the connecting pipe 33 is a connecting tube made of an elastic thermoplastic resin. In other embodiments, the connecting pipe 33 may be a pipe made of metal or the like. The connecting pipe 33 is inserted into the first air chamber 41 through the communication port 44 of the first bag portion 40. The connecting pipe 33 is joined to the two sheet materials 31 and 32 while inserted into the first air chamber 41. Air supplied to the first air chamber 41 and air discharged from the first air chamber 41 flow through the connecting pipe 33.

[0027] <Air bag 30 in a bent state> As shown in Figures 3 and 4, the air bag 30 can be bent (hereinafter also referred to as the "bent state"). In the bent state, the bent portion 60 is folded in a valley fold at the center in the longitudinal direction of the bent portion 60. In the bent state, the first air chamber 41 of the first bag portion 40 and the second air chamber 51 of the second bag portion 50 overlap in the stacking direction. That is, the first joint portion 42 of the first bag portion 40 and the second joint portion 52 of the second bag portion 50 overlap in the stacking direction.

[0028] As shown in Figure 4, in the bent state, the third joint 61 and the intermediate joint 62 of the bent portion 60 are bent. However, since the third joint 61 and the intermediate joint 62 of the bent portion 60 have appropriate bending rigidity, the radius of curvature of the bent portion 60 is a constant value greater than "0". For this reason, in the stacking direction, there is a gap between the portion of the sheet material 32 that constitutes the first channel 71 and the portion of the sheet material 32 that constitutes the second channel 72. In addition, although not shown in Figure 4, in the stacking direction, there is a gap between the portion of the sheet material 32 that constitutes the first part 731 of the intermediate channel 73 and the portion of the sheet material 32 that constitutes the second part 732 of the intermediate channel 73.

[0029] <Support pad 80> As shown in Figure 1, the support pad 80 is shaped like a rectangular plate. The support pad 80 is made of a cushioning material such as urethane. The support pad 80 supports multiple air bladders 30 in a bent state. For example, the support pad 80 may be provided with recesses of a size corresponding to the bent air bladders 30, and the air bladders 30 may be housed in these recesses. Alternatively, the first bag portion 40 of the air bladders 30 may be welded to the support pad 80. Thus, the method of supporting the air bladders 30 by the support pad 80 can be appropriately selected. The multiple air bladders 30 and the support pad 80 are positioned between the surface of the seat back 12 and the cushion pad of the seat back 12.

[0030] <Other components of the pneumatic system 20> Pump 91 is located at the upstream end of piping 93. Pump 91 pumps air into the air bags 30. Pump 91 may be an electric pump equipped with an electric motor as its drive source. Valve device 92 is located downstream of pump 91 in piping 93. Valve device 92 preferably includes a plurality of solenoid valves. Valve device 92 supplies air to the plurality of air bags 30 by switching the connection destination of the plurality of air bags 30 to pump 91. On the other hand, valve device 92 discharges air from the plurality of air bags 30 by switching the connection destination of the plurality of air bags 30 to the outside air. Piping 93 may be an elastic tube or a rigid pipe. The downstream end of piping 93 is connected to the connection pipe 33 of the plurality of air bags 30. In Figure 1, the illustration is simplified, but it is preferable that the downstream end of piping 93 branches to the same number of air bags 30.

[0031] The pneumatic system 20 may be configured to inflate and deflate multiple air bags 30 at different timings, or it may be configured to inflate and deflate multiple air bags 30 at the same timing.

[0032] <Operation of this embodiment> The pneumatic system 20 inflates and deflates multiple air bags 30 by driving a pump 91 and a valve device 92. As shown in Figures 3 to 5, when air is supplied to the air bags 30, air is supplied from the piping 93 to the first air chamber 41 via the connecting pipe 33, and air is supplied from the first air chamber 41 to the second air chamber 51 via the connecting passage 70. As a result, the first air chamber 41 and the second air chamber 51 expand in the stacking direction. On the other hand, when air is discharged from the air bags 30, air is discharged from the first air chamber 41 to the piping 93 via the connecting pipe 33, and air is discharged from the second air chamber 51 to the first air chamber 41 via the connecting passage 70. As a result, the first air chamber 41 and the second air chamber 51 contract in the stacking direction. The air flowing through the connecting passage 70 branches off to avoid the intermediate joint 62 when it flows through the intermediate passage 73 of the connecting passage 70. The branched air flows through the intermediate channel 73 of the connecting channel 70 before merging. In this way, the supply and exhaust of air to the air bag 30 is repeated, causing the air bag 30 to repeatedly expand and contract inside the seat back 12. As a result, the body of the user seated in the seat 10 is massaged.

[0033] As shown in Figures 4 and 5, when the air bag 30 inflates and deflates, the radius of curvature of the bent portion 60, where the connecting channel 70 is provided, increases or decreases. However, in the air bag 30 of this embodiment, the bent portion 60 has an intermediate joint portion 62 with high bending rigidity. Therefore, even when the radius of curvature of the bent portion 60 changes, the connecting channel 70 is less likely to become blocked. In other words, when the air bag 30 inflates and deflates, the airflow from one of the first air chambers 41 and the second air chamber 51 to the other is less likely to be obstructed.

[0034] <Effects of this embodiment> (1) The air bag 30 comprises a first bag section 40 having a first air chamber 41, a second bag section 50 having a second air chamber 51, and a bent section 60 that bends so that the first air chamber 41 and the second air chamber 51 overlap in the stacking direction. In the air bag 30, the bent section 60 has a connecting channel 70 that connects the first air chamber 41 and the second air chamber 51. Therefore, when air is supplied to the air bag 30, the first air chamber 41 and the second air chamber 51 can expand in the stacking direction. On the other hand, when air is exhausted from the air bag 30, the first air chamber 41 and the second air chamber 51 can contract in the stacking direction. In this way, the air bag 30 can easily realize a configuration in which the bag section is stacked in two layers.

[0035] (2) The bent portion 60 of the air bag 30 has an intermediate joint portion 62 with high bending rigidity. Therefore, even when the air bag 30 is supplied with air and vented in a bent state, it is possible to suppress the blockage of the connecting passage 70 of the bent portion 60.

[0036] (3) In the bent portion 60 of the air bag 30, the intermediate joint portion 62 is provided in the intermediate passage 73, which is the intermediate part of the connecting passage 70. The intermediate passage 73 is wider than the first passage 71 and the second passage 72, which are the parts on both sides of the connecting passage 70. In other words, even though the intermediate joint portion 62 is provided in the intermediate passage 73, the reduction in the cross-sectional area of ​​the intermediate passage 73 is suppressed. As a result, when the air bag 30 inflates and deflates, the pressure loss that occurs in the intermediate passage 73 of the connecting passage 70 can be reduced.

[0037] (4) In the intermediate channel 73, the width of the first portion 731 and the second portion 732 gradually changes with respect to the longitudinal direction of the connecting channel 70. As a result, the air bag 30 can suppress the abrupt change in the width of the intermediate channel 73 of the connecting channel 70 with respect to the longitudinal direction of the connecting channel 70. As a result, the air bag 30 can further reduce the pressure loss that occurs in the intermediate channel 73 of the connecting channel 70 when it inflates and deflates.

[0038] (5) In the air bag 30, the intermediate joint 62 is configured to taper in the longitudinal direction of the connecting passage 70. Therefore, when air flows through the intermediate passage 73, the intermediate joint 62 is less likely to be a source of pressure loss.

[0039] (6) During the manufacture of the air bag 30, it is possible to generate the intermediate joint 62 together with the first joint 42, the second joint 52, and the third joint 61. In this respect, the air bag 30 does not require a new configuration or a new manufacturing process in order to provide the intermediate joint 62.

[0040] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0041] The bent portion 60 of the air bag 30 can be changed to the bent portions 60A to 60C of the air bags 30A to 30C shown in Figures 6 to 8. As shown in Figure 6, the bent portion 60A of the air bag 30A according to the first modification example is provided with an intermediate joint portion 62A. In the longitudinal direction of the connecting channel 70, the length of the intermediate joint portion 62A is slightly longer than the intermediate portion 733 of the intermediate channel 73. Also, with respect to the longitudinal direction of the connecting channel 70, the distance between one third joint portion 61 and the intermediate joint portion 62A is constant, and the distance between the other third joint portion 61 and the intermediate joint portion 62A is constant. Therefore, pressure loss is less likely to occur when air flows through the intermediate channel 73. In the first modification example, in the longitudinal direction of the connecting channel 70, the length of the intermediate joint portion 62A may be shorter than the intermediate portion 733 of the intermediate channel 73.

[0042] As shown in Figure 7, the bent portion 60B of the air bag 30B according to the second modification example has a plurality of intermediate joints 62B1, 62B2, and 62B3 that are divided in the longitudinal direction of the connecting channel 70. The plurality of intermediate joints 62B1, 62B2, and 62B3 are arranged in order with spacing between them in the longitudinal direction of the connecting channel 70. When viewed from the stacking direction, the intermediate joints 62B1 and 62B2 have a triangular shape. Therefore, the width of the intermediate joints 62B1 and 62B2 widens towards the center in the longitudinal direction of the connecting channel 70. The intermediate joint 62B3 has a square shape. In other words, the width of the intermediate joint 62B3 is constant with respect to the longitudinal direction of the connecting channel 70. The ease with which the bend of the bent portion 60B of the air bag 30B can be adjusted by adjusting the spacing between the plurality of intermediate joints 62B1, 62B2, and 62B3.

[0043] As shown in Figure 8, the bent portion 60C of the air bag 30C according to the third modification example has two intermediate joints 62C1 and 62C2 that are divided in the width direction. The longitudinal direction of the two intermediate joints 62C1 and 62C2 coincides with the longitudinal direction of the connecting channel 70. A gap exists between the two intermediate joints 62C1 and 62C2. The air bag 30C can allow air to flow between the two intermediate joints 62C1 and 62C2.

[0044] The intermediate joint 62 does not necessarily have to be formed by joining two sheet materials 31 and 32. For example, the intermediate joint 62 may be formed by another sheet-like member. In this case, it is preferable that the other sheet-like member is joined to the two sheet materials 31 and 32.

[0045] The intermediate joint 62 can be an elastic body whose amount of elastic deformation increases as the bent portion 60 of the air bag 30 bends. In this case, the material of the elastic body may be metal or resin. The shape of the elastic body may be rod-shaped or flat plate-shaped. Furthermore, the elastic body does not have to be placed between the two sheet materials 31 and 32. For example, the elastic body may be attached to one of the sheet materials 31 or 32 so as to follow the surface of the sheet material 31 or 32. In this modified example, the elastic body corresponds to the "rigid part".

[0046] The intermediate joint 62 may be a rigid body that can be considered to not deform substantially when the air bag 30 expands and contracts. Preferably, this rigid body has an arc shape corresponding to the radius of curvature of the bent portion 60 when the air bag 30 is in a bent state. In this modified example, the rigid body corresponds to the "rigid part".

[0047] The third joint 61 may be wider than the first joint 42 and the second joint 52. In this case, the third joint 61 can function as an intermediate joint 62. In other words, the portion of the third joint 61 that is wider than the first joint 42 and the second joint 52 functions as a "rigid part".

[0048] The air bag 30 may have a moderate degree of curvature so that it remains bent when no external force is acting on it. For example, such curvature can be created by heating the bent portion 60 and keeping the air bag 30 bent for a period of time.

[0049] The air bladder 30 may be built into the seat cushion 11. If the seat 10 is equipped with an ottoman and armrests, the air bladder 30 may be built into the ottoman and armrests. Thus, the area massaged by the air bladder 30 is not limited to the user's back.

[0050] The use of the air bladder 30 is not limited to massaging the user. For example, the air bladder 30 may be used to support the user's lower back while seated on the seat 10. In this case, the air bladder 30 does not repeatedly inflate and deflate, but is maintained in an inflated state suitable for supporting the user.

[0051] <Summary of this embodiment> The air bag is an air bag comprising two sheet materials, and includes a first bag portion having a first air chamber that expands when air is supplied and contracts when exhausted, and a first joint portion that joins the two sheet materials so as to partition the first air chamber; a second bag portion having a second air chamber that expands when air is supplied and contracts when exhausted, and a second joint portion that joins the two sheet materials so as to partition the second air chamber; a bent portion having a connecting channel that connects the first air chamber and the second air chamber, and a third joint portion that joins the two sheet materials so as to partition the connecting channel, the bent portion being bent so as to overlap the first air chamber and the second air chamber, the connecting channel having a first channel that connects to the first air chamber, a second channel that connects to the second air chamber, and an intermediate channel that is wider than both the first channel and the second channel and connects the first channel and the second channel, and the bent portion further having a rigid portion provided in the intermediate channel that has higher bending rigidity than the sheet materials.

[0052] When the bent section is in a bent state (hereinafter also referred to as the "bent state"), the first air chamber and the second air chamber overlap. When air is supplied to one of the air chambers, air is supplied from one air chamber to the other via the connecting channel of the bent section. As a result, the first and second air chambers expand in the stacking direction. When air is discharged from one of the air chambers, air is discharged from the other air chamber to the first air chamber via the connecting channel of the bent section. As a result, the first and second air chambers contract in the stacking direction. In this way, the air bag can easily realize a configuration in which the bag section is stacked in two layers. Furthermore, the bent section has a rigid section with high bending rigidity. Therefore, the air bag can suppress the radius of curvature of the bent section from becoming extremely small in the bent state. As a result, the air bag can suppress the occlusion of the connecting channel of the bent section in the bent state.

[0053] In an air bag, the intermediate channel includes a first portion connected to the first channel, a second portion connected to the second channel, and an intermediate portion connecting the first and second portions. In the intermediate channel, the intermediate portion is wider than both the first and second channels, the width of the first portion of the intermediate channel gradually narrows towards the first channel, the width of the second portion of the intermediate channel gradually narrows towards the second channel, and the rigid portion is preferably provided across the first portion, the intermediate portion, and the second portion in the intermediate channel.

[0054] In the intermediate channel, the first and second sections gradually widen as they move away from the intermediate section. Therefore, the air bag can suppress abrupt changes in the width of the intermediate channel of the connecting channel relative to the longitudinal direction of the connecting channel. As a result, the air bag can reduce pressure loss in the intermediate channel of the connecting channel during inflation and deflation.

[0055] In an air bag, it is preferable that the width of the rigid portion gradually decreases as it approaches the first flow path and as it approaches the second flow path. In the air bag with the above configuration, the rigid section is configured to taper in the direction of airflow in the intermediate channel. Therefore, when air flows through the intermediate channel, the rigid section is less likely to be a source of pressure loss. As a result, the air bag can further reduce the pressure loss that occurs in the intermediate channel of the connecting channel when it inflates and deflates.

[0056] In an air bag, the rigid portion is preferably an intermediate joint that connects the portions of the two sheets that constitute the intermediate flow path. During the manufacturing of the air bag, it is possible to generate an intermediate joint along with the first, second, and third joints. In this respect, the air bag does not require a new configuration or a new manufacturing process to provide the intermediate joint. [Explanation of symbols]

[0057] 10…Sheet, 20…Pneumatic system, 30,30A~30C…Air bag, 31,32…Sheet material, 40…First bag section, 41…First air chamber, 42…First joint, 50…Second bag section, 51…Second air chamber, 52…Second joint, 60,60A~60C…Bent section, 61…Third joint, 62,62A,62B1~62B3,62C1,62C2…Intermediate joint (rigid section), 70…Connecting channel, 71…First channel, 72…Second channel, 73…Intermediate channel, 731…First section, 732…Second section, 733…Intermediate section

Claims

1. An air bag comprising two sheet materials, A first bag portion having a first air chamber that expands when air is supplied and contracts when exhausted, and a first joining portion that joins the two sheet materials so as to partition the first air chamber, A second bag portion having a second air chamber that expands when air is supplied and contracts when exhausted, and a second joining portion that joins the two sheet materials so as to partition the second air chamber, A bent portion having a connecting channel connecting the first air chamber and the second air chamber, and a third joining portion that joins the two sheet materials so as to partition the connecting channel, wherein the bent portion is bent so as to overlap the first air chamber and the second air chamber, The connecting channel comprises a first channel connected to the first air chamber, a second channel connected to the second air chamber, and an intermediate channel wider than both the first and second channels, connecting the first and second channels. The bent portion is provided in the intermediate channel and further has a rigid portion that has higher bending rigidity than the sheet material. Air bladder.

2. The intermediate flow path includes a first portion connected to the first flow path, a second portion connected to the second flow path, and an intermediate portion connecting the first portion and the second portion. In the aforementioned intermediate channel, the intermediate portion is wider than both the first channel and the second channel. The width of the first portion of the intermediate flow path gradually narrows as it approaches the first flow path. The width of the second portion of the intermediate channel gradually narrows as it approaches the second channel. The rigid portion is provided in the intermediate flow path, spanning the first portion, the intermediate portion, and the second portion. The air bag according to claim 1.

3. The width of the rigid portion gradually decreases as it approaches the first flow path, and also gradually decreases as it approaches the second flow path. The air bag according to claim 2.

4. The rigid portion is an intermediate joint that joins the portions of the two sheets that constitute the intermediate flow path. An air bag according to any one of claims 1 to 3.

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