air bag

Abstract

This invention provides an air bag that allows for the simple implementation of a configuration in which two layers of bag sections are stacked. [Solution] An air bag 30 comprising two sheet materials 31 and 32, comprising: a first bag portion 40 having a first air chamber 41 that expands and contracts; a second bag portion 50 having a second air chamber 51 that expands and contracts; a bent portion 60 connecting the first bag portion 40 and the second bag portion 50, which is bent so that the first air chamber 41 and the second air chamber 51 overlap; a connecting pipe 33 extending from the first bag portion 40; and a locking piece 70 extending from the second bag portion 50. When the bent portion 60 is in a bent state, the connecting pipe 33 is connected to the locking piece 70.

Description

Technical Field

[0005] ,

[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 built into the seat back and seat cushion of the vehicle seat. Then, 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 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 that connects the first bag portion and the second bag portion and is bent so that the first air chamber and the second air chamber overlap; a first extension portion extending from the first bag portion; and a second extension portion extending from the second bag portion, wherein in the bent state where the bent portion is bent, the first extension portion is connected to the second extension portion. [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 according to the first embodiment. [Figure 2] Figure 2 is a front view of the air bag in the first embodiment. [Figure 3] Figure 3 is a front view of the air bag in the first embodiment. [Figure 4] Figure 4 is a cross-sectional view of the deflated air bag in the first embodiment. [Figure 5] Figure 5 is a cross-sectional view of the inflated air bag in the first embodiment. [Figure 6] Figure 6 is a front view of the air bag in the second embodiment. [Figure 7] Figure 7 is a cross-sectional view of the inflated air bag in the second embodiment. [Figure 8] Figure 8 is a front view of the air bag in the third embodiment. [Figure 9]Figure 9 is a front view of the air bag in the modified example. [Modes for carrying out the invention]

[0009] (First Embodiment) The following describes a first embodiment of a sheet equipped with an air bladder. <Configuration of the first 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 bladders 30, a support pad 110, a pump 120, a valve device 130, and piping 140. 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, and three air bladders 30 are arranged in the vertical direction. 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, a bending portion 60, and a locking piece 70. In the first embodiment, the first bag portion 40, the second bag portion 50, and the bending portion 60 are formed by joining 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 their thickness directions 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 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 has a pentagonal shape 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 and 32 so as to partition the second air chamber 51. In this regard, the second joint portion 52 also has a pentagonal shape similar to 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. For this reason, the two sheet materials 31 and 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 first 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 61 and a third joint portion 62. The connection flow path 61 extends linearly. The first end of the connection flow path 61 is connected to the first connection port 43 of the first bag portion 40, and the second end of the connection flow path 61 is connected to the second connection port 53 of the second bag portion 50. That is, the connection flow path 61 connects the first air chamber 41 and the second air chamber 51 so that air can flow from one of the first air chamber 41 and the second air chamber 51 to the other. Thus, air can flow from one of the first air chamber 41 and the second air chamber 51 to the other. The third joint portion 62 partitions the connection flow path 61. The third joint portion 62 is connected to the first joint portion 42 and the second joint portion 52.

[0019] In the first embodiment, the first joint 42, the second joint 52, and the third joint 62 are formed by high-frequency welding of two sheet materials 31 and 32. In other embodiments, the first joint 42, the second joint 52, and the third joint 62 may be formed by heat welding or laser welding of the two sheet materials 31 and 32. Alternatively, the first joint 42, the second joint 52, and the third joint 62 may be formed by bonding the two sheet materials 31 and 32 with an adhesive or the like.

[0020] The locking piece 70 extends from the second bag portion 50. More specifically, the locking piece 70 extends from the portion that constitutes the vertex of the pentagonal second joint portion 52 of the second bag portion 50. The locking piece 70 has a locking hole 71. The locking hole 71 is circular in shape. The locking hole 71 is provided near the tip of the locking piece 70. The locking piece 70 may be made of two sheet materials 31, 32, or it may be made of one of the two sheet materials 31, 32.

[0021] In the first embodiment, the connecting tube 33 is a connecting tube made of an elastic thermoplastic resin. In other embodiments, the connecting tube 33 may be a pipe made of metal or the like. The connecting tube 33 has a tube body 331 and two large-diameter sections 332. The tube body 331 is cylindrical. The tube body 331 is made of a thermoplastic resin such as polyurethane. The outer diameter of the tube body 331 is preferably less than or equal to the inner diameter of the locking hole 71 of the locking piece 70, and the outer diameter of the large-diameter section 332 is preferably larger than the inner diameter of the locking hole 71 of the locking piece 70. Also, the outer diameter of the large-diameter section 332 is larger than the outer diameter of the tube body 331. The two large-diameter sections 332 are spaced apart in the longitudinal direction of the tube body 331. In the following description, the portion between the two large-diameter sections 332 will be referred to as the small-diameter section 333. Therefore, in the longitudinal direction of the connecting pipe 33, the small-diameter portion 333 is located between the two large-diameter portions 332. In the first embodiment, the two large-diameter portions 332 are formed by joining two sheet materials 31 and 32 to the tube body 331.

[0022] The connecting pipe 33 is inserted into the first air chamber 41 via the communication port 44 of the first bag section 40. Air supplied to and discharged from the first air chamber 41 flows through the connecting pipe 33. The connecting pipe 33 extends from the vertices of the pentagonal first joint section 42 of the first bag section 40. The connecting pipe 33 is joined to the two sheet materials 31 and 32 while inserted into the first air chamber 41. The direction in which the connecting pipe 33 extends relative to the first bag section 40 corresponds to the direction in which the locking piece 70 extends relative to the second bag section 50. In other words, the angle between the alignment direction of the first bag section 40 and the second bag section 50 and the extension direction of the connecting pipe 33 is equivalent to the angle between the alignment direction of the first bag section 40 and the second bag section 50 and the extension direction of the locking piece 70.

[0023] <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 at the center in the longitudinal direction of the bent portion 60. In other words, the bent portion 60 is valley-folded along the reference line shown by the dashed line in Figure 2. 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.

[0024] As shown in Figures 3 and 4, the connecting pipe 33 is inserted into the locking hole 71 of the locking piece 70. More specifically, the small-diameter portion 333 of the connecting pipe 33 fits into the locking hole 71 of the locking piece 70. In this respect, the portion of the locking piece 70 in which the locking hole 71 is provided is located between the two large-diameter portions 332 of the connecting pipe 33. In this way, the connecting pipe 33, by being connected to the locking piece 70, positions the first air chamber 41 relative to the second air chamber 51. Positioning here does not mean that the relative positional relationship between the first air chamber 41 and the second air chamber 51 does not change at all, but rather that the positional relationship does not change significantly. In this respect, in the first embodiment, the connecting pipe 33 corresponds to the "first extension portion," and the locking piece 70 corresponds to the "second extension portion."

[0025] Furthermore, when inserting the connecting pipe 33 into the locking hole 71 of the locking piece 70, the locking hole 71 of the locking piece 70 must pass through the large-diameter portion 332 of the connecting pipe 33. For this reason, if the inner diameter of the locking hole 71 of the locking piece 70 is smaller than the outer diameter of the large-diameter portion 332 of the connecting pipe 33, the locking hole 71 of the locking piece 70 will pass through the large-diameter portion 332 of the connecting pipe 33 within the range in which the locking piece 70 can be elastically deformed.

[0026] <Support pad 110> As shown in Figure 1, the support pad 110 is shaped like a rectangular plate. The support pad 110 is made of a cushioning material such as urethane. The support pad 110 supports a plurality of air bladders 30 in a bent state. For example, the support pad 110 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 110. Thus, the method of supporting the air bladders 30 by the support pad 110 can be appropriately selected. The plurality of air bladders 30 and the support pad 110 are positioned between the surface of the seat back 12 and the cushion pad of the seat back 12.

[0027] <Other components of the pneumatic system 20> Pump 120 is located at the upstream end of piping 140. Pump 120 pumps air into the air bags 30. Pump 120 can be an electric pump equipped with an electric motor as its drive source. Valve device 130 is located downstream of pump 120 in piping 140. Valve device 130 preferably consists of multiple solenoid valves. Valve device 130 supplies air to the multiple air bags 30 by switching the connection destination of the multiple air bags 30 to pump 120. On the other hand, valve device 130 discharges air from the multiple air bags 30 by switching the connection destination of the multiple air bags 30 to the outside air. Piping 140 may be an elastic tube or a rigid pipe. The downstream end of piping 140 is connected to the connection pipes 33 of the multiple air bags 30. In Figure 1, the illustration is simplified, but it is preferable that the downstream end of piping 140 branches to the same number of air bags 30.

[0028] 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.

[0029] <Operation of the First Embodiment> The pneumatic system 20 inflates and deflates the multiple air bags 30 by driving the pump 120 and the valve device 130. As shown in Figures 4 and 5, when air is supplied to the air bags 30, air is supplied to the first air chamber 41 via the connecting pipe 33. Subsequently, the air supplied to the first air chamber 41 is supplied to the second air chamber 51 via the connecting passage 61 of the bent section 60. 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 second air chamber 51 via the connecting passage 61, and air is discharged from the first air chamber 41 via the connecting pipe 33. As a result, the first air chamber 41 and the second air chamber 51 contract in the stacking direction. In this way, the supply and exhaust of air to the air bags 30 is repeated, causing the air bags 30 to repeatedly inflate and deflate inside the seat back 12. As a result, the body of the user sitting in the seat 10 is massaged.

[0030] The first bag section 40 and the second bag section 50 are connected via a bent section 60, and also via a connecting pipe 33 and a locking piece 70. In other words, there are two connection points between the first bag section 40 and the second bag section 50. Therefore, even when the air bag 30 inflates and deflates with the first bag section 40 and the second bag section 50 stacked together, one of the first bag section 40 and the second bag section 50 is less likely to shift relative to the other. Thus, the first bag section 40 and the second bag section 50 inflate and deflate while maintaining their relative positional relationship.

[0031] <Effects of the First Embodiment> (1) In the bent state, the first air chamber 41 and the second air chamber 51 of the air bag 30 overlap. Therefore, compared to the case where the air bag 30 has a single air chamber, the air bag 30 can be inflated more in the stacking direction. In addition, the first bag section 40 having the first air chamber 41 and the second bag section 50 having the second air chamber 51 are connected via the connecting pipe 33 and the locking piece 70 in addition to the bent section 60. Therefore, when the air bag 30 inflates and deflates, displacement of one of the first bag section 40 and the second bag section 50 relative to the other can be suppressed. In this way, the air bag 30 can easily realize a configuration in which the bag sections are stacked in two layers.

[0032] (2) The locking piece 70 is connected to the connecting pipe 33 which is necessary for supplying and discharging air to the first air chamber 41. Therefore, the air bag 30 does not need to have anything to lock the locking piece 70 to, in addition to the connecting pipe 33.

[0033] (3) When the small-diameter portion 333 of the connecting pipe 33 is inserted into the locking hole 71 in the bent state, the portion of the locking piece 70 in which the locking hole 71 is provided is positioned between the two large-diameter portions 332 of the connecting pipe 33. As a result, the locking piece 70 is less likely to move in the longitudinal direction of the connecting pipe 33. In this way, when the air bag 30 expands and contracts, displacement of one of the first bag portion 40 and the second bag portion 50 relative to the other can be further suppressed.

[0034] (4) In the air bag 30, the first air chamber 41 and the second air chamber 51 are connected so that air flows through the connecting passage 61. In other words, the air bag 30 does not need to have another connecting pipe 33 connected to the second air chamber 51 in addition to the connecting pipe 33 connected to the first air chamber 41. Furthermore, since the connecting passage 61 is provided in the bent section 60 that connects the first bag section 40 and the second bag section 50, no new configuration is required to provide the connecting passage 61.

[0035] (Second Embodiment) The air bag 30A of the second embodiment will now be described. The air bag 30A of the second embodiment has a different configuration of the connecting pipe 33A compared to the air bag 30 of the first embodiment. Therefore, in the following description, components common to the first embodiment will be denoted by the same reference numerals as in the first embodiment and their descriptions will be omitted.

[0036] <Configuration of the second embodiment> As shown in Figure 6, the air bag 30A is composed of two sheet materials 31 and 32 and a connecting pipe 33A. The air bag 30A also includes a first bag section 40, a second bag section 50, a bent section 60, and a locking piece 70.

[0037] The connecting pipe 33A has a tube body 331 and a guide 334. The guide 334 is cylindrical in shape. The guide 334 is joined to the tube body 331. In the second embodiment, the guide 334 is constructed by welding two sheet materials 31 and 32 to the tube body 331. In this respect, the guide 334 may be formed when forming the first bag portion 40 and the second bag portion 50. In other embodiments, the guide 334 may be a metal or resin pipe. The coefficient of friction between the guide 334 and the locking piece 70 is smaller than the coefficient of friction between the tube body 331 and the locking piece 70. Also, the outer diameter of the guide 334 is less than or equal to the inner diameter of the locking hole 71 of the locking piece 70.

[0038] As shown by the dashed line in Figure 7, in the bent state, the connecting pipe 33A is inserted into the locking hole 71 of the locking piece 70. More specifically, the guide 334 of the connecting pipe 33A is housed in the locking hole 71 of the locking piece 70. In this way, the connecting pipe 33A is locked to the locking piece 70, thereby positioning the first air chamber 41 relative to the second air chamber 51. In this respect, in the second embodiment, the connecting pipe 33A corresponds to the "first extension" and the locking piece 70 corresponds to the "second extension".

[0039] <Operation of the second embodiment> As shown by the solid lines in Figure 7, when air is supplied to the air bag 30A, the first air chamber 41 and the second air chamber 51 inflate. Here, the first bag section 40 and the second bag section 50 are connected via the bent section 60, and also via the connecting pipe 33A and the locking piece 70. Therefore, even when the air bag 30A inflates with the first bag section 40 and the second bag section 50 stacked, one of the first bag section 40 and the second bag section 50 is less likely to shift relative to the other. Thus, the air bag 30A inflates and deflates while maintaining the stacked state of the first bag section 40 and the second bag section 50. Furthermore, in the second embodiment, the locking piece 70 is movable relative to the connecting pipe 33A in the longitudinal direction of the connecting pipe 33A. Therefore, as shown by the solid and dashed lines in Figure 7, when the air bag 30A inflates and deflates, the locking piece 70 slides against the connecting pipe 33A. In this respect, the guide 334 of the connecting pipe 33A in the second embodiment can be said to be configured to improve sliding performance with respect to the locking piece 70.

[0040] <Effects of the second embodiment> In addition to the effects (1), (2), and (4) of the first embodiment, the second embodiment can obtain the following effects.

[0041] (5) When the air bag 30A inflates and deflates, the locking piece 70 slides against the connecting pipe 33A. Therefore, when the air bag 30A inflates and deflates, one of the first bag portion 40 and the second bag portion 50 can be slightly misaligned relative to the other. In this way, when the air bag 30A inflates and deflates, it is possible to suppress the load on the connection between the connecting pipe 33A and the locking piece 70.

[0042] (Third embodiment) The air bag 30B of the third embodiment will now be described. Compared to the air bag 30 of the first embodiment, the air bag 30B of the third embodiment has a different configuration of the connecting pipe 33B and the locking piece 70B. Therefore, in the following description, components common to the first embodiment will be given the same reference numerals as in the first embodiment and their description will be omitted.

[0043] <Configuration of the third embodiment> As shown in Figure 8, the air bag 30B is composed of two sheet materials 31 and 32 and a connecting pipe 33B having a tube body 331. The air bag 30B also includes a first bag section 40, a second bag section 50, a bent section 60, and a locking piece 70B.

[0044] The locking piece 70B extends from the second bag portion 50. More specifically, the locking piece 70B extends from the portion that constitutes the vertex of the pentagonal second joint portion 52 of the second bag portion 50. The locking piece 70B has a locking hole 71B. The locking hole 71B is slit-shaped. The longitudinal direction of the locking hole 71B coincides with the longitudinal direction of the locking piece 70B. The locking piece 70B may be made of two sheet materials 31, 32, or it may be made of one of the two sheet materials 31, 32.

[0045] Although not shown in the diagram, in the bent state, the connecting pipe 33B is inserted into the locking hole 71B of the locking piece 70B. In this way, the connecting pipe 33B locks onto the locking piece 70B, thereby positioning the first air chamber 41 relative to the second air chamber 51. In this respect, in the third embodiment, the connecting pipe 33B corresponds to the "first extension" and the locking piece 70B corresponds to the "second extension".

[0046] <Operation of the Third Embodiment> When air is supplied to the air bag 30B, the first air chamber 41 and the second air chamber 51 inflate. Here, the first bag portion 40 and the second bag portion 50 are connected via the bent portion 60, and also via the connecting pipe 33B and the locking piece 70B. Therefore, even when the air bag 30B inflates with the first bag portion 40 and the second bag portion 50 stacked, one of the first bag portion 40 and the second bag portion 50 is less likely to shift relative to the other. Thus, the air bag 30B inflates and deflates while maintaining the stacked state of the first bag portion 40 and the second bag portion 50. Furthermore, in the third embodiment, the locking piece 70B is movable relative to the connecting pipe 33B in the direction in which the locking hole 71B of the locking piece 70B is formed. Therefore, when the air bag 30B inflates and deflates, the locking piece 70B slides against the connecting pipe 33B.

[0047] <Effects of the Third Embodiment> The third embodiment can obtain the following effects in addition to the effects (1), (2), and (4) of the first embodiment.

[0048] (6) When the air bag 30B inflates and deflates, the locking piece 70B moves relative to the connecting pipe 33B. As a result, when the air bag 30B inflates and deflates, one of the first bag section 40 and the second bag section 50 can be slightly misaligned relative to the other. In this way, when the air bag 30B inflates and deflates, it is possible to suppress the load on the connection part of the connecting pipe 33B and the locking piece 70B.

[0049] <Example of changes> The above-described embodiments can be implemented with the following modifications. The above-described embodiments and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0050] The air bag 30 according to the first embodiment may be changed to the air bag 30C shown in Figure 9. As shown in Figure 9, in the air bag 30C, the connecting pipe 33 extends from the first bag section 40. The longitudinal direction of the connecting pipe 33 coincides with the longitudinal direction of the connecting channel 61. Similarly, the locking piece 70C extends from the second bag section 50. The extending direction of the locking piece 70C coincides with the longitudinal direction of the connecting channel 61. Furthermore, the longitudinal direction of the connecting pipe 33, the longitudinal direction of the connecting channel 61, and the extending direction of the locking piece 70C coincide with the direction of the line segment connecting the center of the first air chamber 41 and the center of the second air chamber 51. According to this modification, in the air bag 30C, the first bag section 40 and the second bag section 50 are connected in a balanced manner. As a result, when the air bag 30C expands and contracts, it is possible to suppress displacement or tilting of one of the first bag section 40 and the second bag section 50 relative to the other.

[0051] In the first embodiment, the air bag 30 may be provided with a connecting pipe for supplying air to the second air chamber 51 of the second bag portion 50 and for discharging air from the second air chamber 51. In this case, the bent portion 60 does not need to have a connecting passage 61. The same applies to other embodiments.

[0052] In the first embodiment, the manner in which the connecting pipe 33 and the locking piece 70 are connected can be changed as appropriate. For example, the connecting pipe 33 and the locking piece 70 may be connected by welding and bonding, or by other means. In other words, the connecting pipe 33 and the locking piece 70 may be connected in a way that prevents them from being detached. The same applies to other embodiments.

[0053] In the first embodiment, the air bag 30 may include a locking piece 70 extending from the first bag portion 40. The locking piece 70 extending from the first bag portion 40 is connected to a locking piece 70 extending from the second bag portion 50. In this modified example, the locking piece 70 extending from the first bag portion 40 corresponds to the "first extension," and the locking piece 70 extending from the second bag portion 50 corresponds to the "second extension." Thus, the first bag portion 40 may be connected to the locking piece 70 of the second bag portion 50 via a configuration different from that of the connecting pipe 33.

[0054] In the first embodiment, the air bladder 30 may be built into the seat cushion 11. If the seat 10 includes 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. The same applies to other embodiments.

[0055] In the first embodiment, 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 or other areas 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. The same applies to other embodiments.

[0056] <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 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 that connects the first bag portion and the second bag portion and bends so that the first air chamber and the second air chamber overlap; a first extension portion extending from the first bag portion; and a second extension portion extending from the second bag portion, wherein in the bent state where the bent portion is bent, the first extension portion is connected to the second extension portion.

[0057] In the bent state, the first and second air chambers of the air bag overlap. Therefore, the air bag can expand significantly in the thickness direction of the two sheet materials compared to a case with a single air chamber. Furthermore, the first bag section having the first air chamber and the second bag section having the second air chamber are connected not only by the bent section but also by the first and second extended sections. Thus, when the air bag expands and contracts, displacement of one of the first and second bag sections relative to the other can be suppressed. In this way, the air bag can easily realize a configuration in which the bag sections are stacked in two layers.

[0058] In an air bag, the first extension is a connecting pipe through which air supplied to the first air chamber and air discharged from the first air chamber flows, and the second extension has a locking hole into which the connecting pipe is inserted, and it is preferable that in the bent state, the connecting pipe is inserted into the locking hole.

[0059] The air bag can have a connecting pipe, which is necessary for supplying and discharging air to the first air chamber, function as a first extension. Therefore, the air bag does not need to have a separate structure equivalent to the first extension in addition to the connecting pipe.

[0060] In an air bag, the connecting tube has two large-diameter sections and a small-diameter section having a smaller outer diameter than the two large-diameter sections, and it is preferable that the small-diameter sections are located between the two large-diameter sections in the longitudinal direction of the connecting tube.

[0061] When the small-diameter portion of the connecting pipe is inserted into the locking hole in the bent state, the portion of the second extension where the locking hole is provided is positioned between the two large-diameter portions of the connecting pipe. In this case, the second extension becomes less likely to move in the longitudinal direction of the connecting pipe. As a result, when the air bladder expands and contracts, displacement of one of the first or second bag portions relative to the other can be further suppressed.

[0062] In an air bag, it is preferable that the bent portion has a connecting channel through which air flows while 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.

[0063] In an air bag, the first air chamber and the second air chamber are connected so that air flows through a connecting channel. In other words, the air bag does not need to have a connecting pipe connected to the first air chamber and a connecting pipe connected to the second air chamber. Furthermore, since the connecting channel is provided at the bend connecting the first and second bag sections, there is no need to add any new components to provide the connecting channel.

[0064] In an air bag, the locking hole is preferably circular in shape. By making the inner diameter of the locking hole of the air bag equal to the outer diameter of the connecting pipe, the locking piece can be made less likely to move relative to the connecting pipe. In other words, when the air bag inflates and deflates, displacement of one of the first bag section and the second bag section relative to the other can be further suppressed.

[0065] In the aforementioned bent state, it is preferable that the locking hole is shaped like a slit extending in the longitudinal direction of the connecting pipe. When the air bag inflates and deflates, the second extension can move relative to the connecting pipe in the direction of slit formation. Therefore, by connecting the locking portion and the second extension, it is possible to prevent one of the first and second bag portions from being excessively restrained relative to the other. [Explanation of Symbols]

[0066] 10…Sheet, 20…Pneumatic system, 30,30A~30C…Air bag, 31,32…Sheet material, 33,33A,33B…Connecting tube, 331…Tube body, 332…Large diameter section, 333…Small diameter section, 334…Guide, 40…First bag section, 41…First air chamber, 42…First joint, 50…Second bag section, 51…Second air chamber, 52…Second joint, 60…Bend section, 61…Connecting channel, 62…Third joint, 70,70B,70C…Locking piece, 71,71B…Locking hole

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 connects the first bag portion and the second bag portion, and bends so that the first air chamber and the second air chamber overlap, A first extension portion extending from the first bag portion, It comprises a second extension portion extending from the second bag portion, In the bent state in which the bent portion is bent, the first extension portion is connected to the second extension portion. Air bladder.

2. The first extension is a connecting pipe through which air supplied to the first air chamber and air discharged from the first air chamber flows. The second extension has a locking hole into which the connecting pipe is inserted. In the aforementioned bent state, the connecting pipe is inserted into the locking hole. The air bag according to claim 1.

3. The connecting pipe has two large-diameter sections and a small-diameter section with an outer diameter smaller than the two large-diameter sections. In the longitudinal direction of the connecting pipe, the small diameter portion is provided between the two large diameter portions. The air bag according to claim 2.

4. The bent portion has a connecting channel through which air flows while 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. An air bag according to any one of claims 1 to 3.

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