Seat-mounted airbag device

Abstract

The present disclosure provides a seat-mounted airbag device. The seat-mounted airbag device includes an airbag main body including an outer airbag portion and an inner airbag portion. The outer airbag portion includes a front-rear chamber, a left-right chamber, a top chamber, and a tether. The front-rear chamber is configured to deploy from a side of a head of an occupant and to a front side, and is disposed at the side of the head. The left-right chamber is configured to deploy from a front side end of the front-rear chamber to an inner side in a seat width direction, and is disposed at a front side of a face of the occupant. The top chamber is configured to deploy from an inner side end of the left-right chamber to a rear side, and is disposed at the other side of the head. The tether links the front-rear chamber and the top chamber. The inner airbag portion is disposed to deploy between the front-rear chamber, the left-right chamber, and the top chamber.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a seat-mounted airbag device. BACKGROUND

[0002] Conventionally, there is known a passenger restraint device that includes a safety airbag module having a high-rigidity support chamber mounted on one side of a seat back and deployed in an "L" shape as viewed from above at the time of a front surface collision of a vehicle, and a low-rigidity absorption chamber formed in a convex shape toward a passenger side on a restraint surface of the support chamber at a front side of a head of the passenger (for example, refer to International Publication No. 2019 / 166268) SUMMARY

[0003] However, in the seat-mounted airbag device that is deployed on one side, since a fixing point at a rear side of the safety airbag body becomes a cantilever support at one side of the seat back, the safety airbag body rotates in a direction away from the head of the passenger with the fixing point as a center during an upper body restraint process in the latter half of the collision. Further, since the restraint surface of the absorption chamber is provided in a convex shape, the head of the passenger easily deviates from the center of the absorption chamber to the outside. As a result, there is a concern that the head of the passenger is pulled out of the safety airbag body.

[0004] Further, in a safety airbag device that is deployed from a rear side of the head of the passenger to restrain the upper body (chest) of the passenger, there is a possibility that the safety airbag body is lifted during the restraint process so that the restraint is not sufficiently performed. As a countermeasure for this situation, a structure that restrains only the head of the passenger by the safety airbag body is considered. However, since a large tensile load acts on only the head of the passenger at the time of the restraint, there is a possibility that the inclination (rear curvature) of the neck of the passenger becomes large.

[0005] Therefore, an object of the present disclosure is to obtain a seat-mounted airbag device that can suppress the head of the passenger from being pulled out of the safety airbag body and the inclination of the neck of the passenger at the time of the head restraint of the passenger.

[0006] To achieve the above object, a seat-mounted airbag apparatus according to a first aspect of the present disclosure includes a main airbag body configured to include: an outer airbag portion having a front-rear chamber, a left-right chamber, and a top-end chamber, and having a tether, wherein the front-rear chamber passes from one side of a passenger's head and deploys toward a seat front side by gas injected from an inflator that operates in response to detection or prediction of a vehicle collision, and is disposed at the one side of the passenger's head; the left-right chamber deploys toward a seat width direction inner side from a seat front side end of the front-rear chamber, and is disposed at a seat front side of the passenger's face; the top-end chamber deploys toward a seat rear side from a seat width direction inner side end of the left-right chamber, and is disposed at the other side of the passenger's head; the tether links the front-rear chamber and the top-end chamber; and an inner airbag portion disposed so as to deploy between the front-rear chamber and the left-right chamber and the top-end chamber by the gas flowing from the outer airbag portion, and having a head restraint surface that restrains the passenger's head.

[0007] According to the first aspect, when a vehicle collision is detected or predicted, the inflator is operated to inject gas, thereby causing the outer airbag portion to deploy. That is, the front-rear chamber of the outer airbag portion passes from one side of a passenger's head and deploys toward a seat front side, and is disposed at the one side of the passenger's head, and the left-right chamber deploys toward a seat width direction inner side from a seat front side end of the front-rear chamber, and is disposed at a seat front side of the passenger's face. Also, the top-end chamber of the outer airbag portion deploys toward a seat rear side from a seat width direction inner side end of the left-right chamber, and is disposed at the other side of the passenger's head, and the front-rear chamber and the top-end chamber are linked by the tether. Further, the inner airbag portion having a head restraint surface that restrains the passenger's head is disposed so as to deploy between the front-rear chamber and the left-right chamber and the top-end chamber by the gas flowing from the outer airbag portion. That is, the front surface portion and the left and right side surface portions of the inner airbag portion having the head restraint surface are covered by the outer airbag portion.

[0008] Therefore, the inner side airbag portion receives a reaction force from the outer side airbag portion. Thus, the occupant's head is restrained by the inner side airbag portion while being pressed toward the seat front side. That is, it is possible to restrain the amount of movement of the occupant's head toward the front side to be smaller than the amount of movement of the occupant's chest toward the front side determined by the restraining force of the seat belt, when the occupant's head is restrained. In other words, it is possible to make the occupant's head travel toward the front side longer, and thus to restrain the tensile load acting on the occupant's head lower. Thus, it is possible to restrain the occupant's neck from leaning backward. Further, since the front-rear chamber and the top end chamber are linked together by the tether, the top end chamber is difficult to move in a direction away from the front-rear chamber. Thus, it is possible to restrain the occupant's head from escaping from the airbag main body.

[0009] Further, the seat-mounted type airbag device of the second mode is such that, in the seat-mounted type airbag device of the first mode, a protruding portion protruding toward the seat rear side compared to the front-rear chamber side is formed at the top end chamber side in the head restraint surface of the inner side airbag portion when viewed from above.

[0010] According to the second mode, a protruding portion protruding toward the seat rear side compared to the front-rear chamber side is formed at the top end chamber side in the head restraint surface of the inner side airbag portion when viewed from above. Therefore, when the occupant's head restraint by the inner side airbag portion is performed, the occupant's head will be difficult to escape toward the top end chamber side. That is, the occupant's head escape from the airbag main body is more effectively restrained.

[0011] Further, the seat-mounted type airbag device of the third mode is such that, in the seat-mounted type airbag device of the second mode, a length in the seat front-rear direction of the inner side airbag portion except for the protruding portion is set to be longer compared to a length in the seat width direction when viewed from above.

[0012] According to the third mode, a length in the seat front-rear direction of the inner side airbag portion except for the protruding portion is set to be longer compared to a length in the seat width direction when viewed from above. Therefore, compared to a case where the length in the seat front-rear direction of the inner side airbag portion except for the protruding portion is set to be shorter compared to the length in the seat width direction, it is possible to ensure a longer amount of travel of the occupant's head toward the seat front side. Thus, the occupant's neck is restrained from leaning backward.

[0013] Further, the seat-mounted type airbag device of the fourth aspect is such that, in the seat-mounted type airbag device of the first aspect, the inboard airbag portion is formed in a substantially elliptical shape having a predetermined thickness in the seat width direction in a plan view, and is obliquely arranged with respect to the seat front-rear direction in a manner such that the seat rear side end portion thereof is distanced from the front-rear chamber.

[0014] According to the fourth aspect, the inboard airbag portion is formed in a substantially elliptical shape having a predetermined thickness in the seat width direction in a plan view, and is obliquely arranged with respect to the seat front-rear direction in a manner such that the seat rear side end portion thereof is distanced from the front-rear chamber. Therefore, the occupant's head is restrained in a manner of being sandwiched by the outboard airbag portion and the inboard airbag portion. Thus, the occupant's head from the airbag main body can be suppressed. Further, the occupant's head can be made to travel longer to the front right, and thus the tensile load acting on the occupant's head can be suppressed to be lower. Thus, the occupant's neck can be suppressed from reclining.

[0015] Further, the seat-mounted type airbag device of the fifth aspect is such that, in the seat-mounted type airbag device of any one of the first to fourth aspects, a ventilation hole through which the gas is discharged is formed in the inboard airbag portion, and an opening area of the ventilation hole is set to be larger than an opening area of a flow inlet for allowing the gas to flow from the outboard airbag portion to the inboard airbag portion.

[0016] According to the fifth aspect, the opening area of the ventilation hole formed in the inboard airbag portion is set to be larger than the opening area of the flow inlet for allowing the gas to flow from the outboard airbag portion to the inboard airbag portion. Therefore, the internal pressure of the inboard airbag portion decreases at the time of the occupant's head restraint, and thus the inboard airbag portion becomes soft. Thus, the occupant's head can be made to travel longer to the front right, and thus the occupant's head from the airbag main body can be suppressed, and the occupant's neck can be suppressed from reclining.

[0017] Further, the seat-mounted type airbag device of the sixth aspect is such that, in the seat-mounted type airbag device of any one of the first to fourth aspects, a check valve that allows the inflow of the gas from the outboard airbag portion to the inboard airbag portion and restricts the outflow of the gas from the inboard airbag portion to the outboard airbag portion is provided at a flow inlet for allowing the gas to flow from the outboard airbag portion to the inboard airbag portion, and a variable ventilation hole that is closed when the gas is flowing from the outboard airbag portion to the inboard airbag portion and is opened at the time of the occupant's head restraint is provided in the inboard airbag portion.

[0018] According to the sixth aspect, a variable vent hole is provided on the inner side airbag portion, the variable vent hole being closed when gas is flowing from the outer side airbag portion to the inner side airbag portion and being opened when the occupant's head is restrained. Thus, when the occupant's head is restrained, the internal pressure of the inner side airbag portion decreases, so that the inner side airbag portion becomes soft. Thus, since the occupant's head can be made to travel further to the side, the occupant's head is prevented from being pulled out of the airbag main body, and the occupant's neck is prevented from being tilted backward.

[0019] Further, the seat-mounted type airbag device according to the seventh aspect is the seat-mounted type airbag device according to any one of the first to sixth aspects, in which the tether is formed in a substantially "Y" shape in plan view with one end portion attached to the top end chamber, and the other end portions on the front side and the rear side, which are spaced apart in the seat front-rear direction, are attached to the front-rear chambers, respectively.

[0020] According to the seventh aspect, the tether is formed in a substantially "Y" shape in plan view with one end portion attached to the top end chamber, and the other end portions on the front side and the rear side, which are spaced apart in the seat front-rear direction, are attached to the front-rear chambers, respectively. In this case, if the top end chamber and the front-rear chambers are connected by a linear tether, when the occupant's head is restrained, the front-rear chambers can be bent from the portions to which the tether is attached, so that the occupant's head can be pulled out of the airbag main body. In contrast, since the other end portions on the front side and the rear side of the tether are attached to the front-rear chambers, which are spaced apart in the seat front-rear direction, the tension of the tether is dispersed, so that the bending of the front-rear chambers is suppressed. Thus, the occupant's head is prevented from being pulled out of the airbag main body.

[0021] As described above, according to the present disclosure, in the seat-mounted type airbag device, the occupant's head can be prevented from being pulled out of the airbag main body when the occupant's head is restrained, and the occupant's neck can be prevented from being tilted backward. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a side view showing a state after deployment of the seat-mounted type airbag device according to the first embodiment.

[0023] Figure 2 is a plan view showing a state after deployment of the seat-mounted type airbag device according to the first embodiment.

[0024] Figure 3FIG. 6 is a partially enlarged schematic front view for showing an inflow port between the outboard airbag portion and the inboard airbag portion of the airbag main body of the seat-mounted type airbag device according to the first embodiment.

[0025] Figure 4 FIG. 7 is a plan view for showing a state after deployment of the seat-mounted type airbag device according to a modification of the first embodiment.

[0026] Figure 5 FIG. 8 is a plan view for showing a state after deployment of the seat-mounted type airbag device according to the second embodiment.

[0027] Figure 6 FIG. 9 is a plan view for showing a state after deployment of the seat-mounted type airbag device according to the third embodiment.

[0028] Figure 7A FIG. 10 is a plan view for showing a state at an early stage of deployment of the seat-mounted type airbag device according to the fourth embodiment.

[0029] Figure 7B FIG. 11 is a plan view for showing a state at a late stage of deployment of the seat-mounted type airbag device according to the fourth embodiment.

[0030] Figure 8A FIG. 12 is a partially enlarged side cross-sectional view for showing a structure of the variable vent. Figure 7A FIG. 13 is a partially enlarged side cross-sectional view for showing a structure of the variable vent.

[0031] Figure 8B FIG. 14 is a partially enlarged side cross-sectional view for showing a structure of the variable vent. Figure 7B FIG. 15 is a partially enlarged side cross-sectional view for showing a structure of the variable vent. DETAILED DESCRIPTION

[0032] Hereinafter, the embodiments according to the present disclosure will be described in detail based on the drawings. In addition, in order to facilitate the description, the arrow mark UP indicated in each drawing is assumed to be a seat upward direction, the arrow mark FR is assumed to be a seat front direction, and the arrow mark RH is assumed to be a seat right direction. Therefore, in the following description, in the case where the up-down, front-rear, and left-right directions are described without being particularly described, the up-down, front-rear, and left-right directions are assumed to indicate the up-down, front-rear, and left-right directions of the vehicle seat. Furthermore, the left-right direction is synonymous with the seat width direction.

[0033] As shown in FIG. 1, the seat-mounted type airbag device 1 according to the first embodiment is provided with an airbag main body 2 and an inflator 3. Figure 1 Figure 2 ​As shown, a seat-mounted airbag device (hereinafter, simply referred to as "airbag device") 30 according to the present embodiment is provided at the seat width direction outer side (the left side as shown) of a vehicle seat 10. In addition, although the vehicle seat 10 according to the present embodiment is described as a rear seat, the airbag device 30 can also be provided at a front seat. Further, as one example, the rear seat is a rear seat on the side of a side window glass (omitted from the drawing) on the right side.

[0034] Accordingly, the airbag main body 32 described later passes between the head Ph of the occupant P on the side of the side window glass and the head of the occupant (omitted from the drawing) on the center seat side and deploys. In addition, the airbag main body 32 can also pass between the side window glass and the head Ph of the occupant P and deploy. Further, as one example, the "occupant P" in the present embodiment refers to an occupant corresponding to a dummy AM50 (50th percentile of an American adult male).

[0035] <First Embodiment>

[0036] First, the airbag device 30 according to the first embodiment will be described. As shown in Figure 1 Figure 2 , the vehicle seat 10 has a seat cushion 12 on which the occupant P sits (supports the hips and thighs of the occupant P), a seat back 14 that supports the back of the occupant P, and a headrest 16 that supports the head Ph of the occupant P.

[0037] Further, at the left side (one side) of the headrest 16, a housing portion 20 that houses the airbag main body 32 described later is disposed. In addition, the housing portion 20 is supported on side frames (omitted from the drawing) that constitute the left and right side portions of a seat back frame provided inside the seat back 14.

[0038] If described in detail, the side frame is formed in a flat plate shape extending in the up-down direction, and on the outer surface thereof, a cylindrical inflator 18 (refer to Figure 1 ) is integrally installed in such a manner that the axis center portion thereof faces the up-down direction via a bracket (omitted from the drawing) or the like. Further, on the outlet port (omitted from the drawing) that is the upper end portion of the inflator 18, the lower end portion of a metal pipe (omitted from the drawing) that is a supply pipe is installed by fitting, and the upper portion of the metal pipe is inserted into and fixed to the housing portion 20.

[0039] Thus, the housing portion 20 is supported on the side frame via the inflator 18 and the metal pipe. In addition, the rear end portion of the airbag main body 32 described later is installed at the upper end portion of the metal pipe, so that gas ejected from the inflator 18 can be supplied to the inside of the airbag main body 32.​

[0040] The inflation device 18 is electrically connected to the airbag ECU (not shown) installed on the vehicle, and the detection devices such as the acceleration sensor installed on the vehicle (not shown) are also electrically connected to the airbag ECU. Therefore, when a collision is detected by the detection device, the inflation device 18 will operate via the airbag ECU to instantaneously eject gas.

[0041] Alternatively, the inflation device 18 may not be a structure that operates by detecting a vehicle collision, but rather a structure that operates by predicting a vehicle collision using a collision prediction sensor or the like (figure omitted).

[0042] like Figure 1 , Figure 2 As shown, the airbag device 30 has an airbag body 32, which is ejected by gas from the inflation device 18, causing a portion of the housing 20 to rupture and eject, and deploying forward from the rear side (specifically the left rear side) of the head Ph of the occupant P seated on the vehicle seat 10. Furthermore, the airbag body 32 is configured as a dual airbag structure comprising an outer airbag portion 33 and an inner airbag portion 22.

[0043] The outer airbag 33 has a front and rear chamber 34, left and right chambers 35, and a top chamber 36. The front and rear chambers 34 extend forward from the left side of the head Ph of the occupant P and are positioned on the left side of the head Ph of the occupant P (between the head Ph of the occupant P on the side window glass side and the head of the occupant on the center seat side, not shown). The left and right chambers 35 extend inward from the front end of the front and rear chambers 34 in the seat width direction and are positioned in front of the face of the occupant P. The top chamber 36 extends rearward from the inner end of the left and right chambers 35 in the seat width direction and is positioned on the right side of the head Ph of the occupant P.

[0044] Furthermore, the outer airbag portion 33 has a strap 38 of predetermined width, which connects the middle portion of the upper end of the front and rear chambers 34 to the top (rear) portion of the upper end of the top chamber 36. That is, one end 38A of the strap 38 is sewn onto the top (rear) portion of the upper end of the top chamber 36, and the other end 38B of the strap 38 is sewn onto the middle portion of the upper end of the front and rear chambers 34.

[0045] Thus, the outer side airbag portion 33 is provided in a state of being bent into a substantially "J" shape in plan view, so that it can restrain at least the head Ph of the occupant P together with the inner side airbag portion 22. In addition, as shown in Figure 2 Since the tether 38 is located at the upper side of the head Ph of the occupant P, it does not interfere (touch) with the head Ph of the occupant P.

[0046] The inner side airbag portion 22 is configured in a manner of being deployed between the front and rear chambers 34, the left and right chambers 35 and the top end chamber 36, in other words, in the space surrounded by the front and rear chambers 34, the left and right chambers 35 and the top end chamber 36, by inflow of gas from the outer side airbag portion 33, with a height equivalent to that of the outer side airbag portion 33.

[0047] If described in detail, the inner side airbag portion 22 has a left side surface portion 24 opposed to the front and rear chamber 34, a front surface portion 25 opposed to the left and right chambers 35, a right side surface portion 26 opposed to the top end chamber 36, and a rear surface portion 28 opposed to the head Ph of the occupant P. In addition, as shown in Figure 1 Figure 2 The rear surface portion 28 becomes a head restraint surface that restrains the head Ph of the occupant P.

[0048] Further, the inner side airbag portion 22 has an upper surface portion 23 that extends integrally rearward from the upper end portion of the front surface portion 25, with its peripheral portion being attached at the upper end portions of the left side surface portion 24, the right side surface portion 26 and the rear surface portion 28 by sewing, and a lower surface portion 27 that extends integrally rearward from the lower end portion of the front surface portion 25, with its peripheral portion being attached at the lower end portions of the left side surface portion 24, the right side surface portion 26 and the rear surface portion 28 by sewing.

[0049] Further, as shown in Figure 3 At the rear surface central portion of the left and right chambers 35 and the central portion of the front surface portion 25, opening portions 35A and 25A, respectively, of circular shape in front view are formed, and the peripheral portions of the respective opening portions 35A and 25A are integrally joined together with the reinforcing cloth 41 by sewing. Thus, a structure is obtained in which the outer side airbag portion 33 and the inner side airbag portion 22 are integrally joined together, and the gas inflow port 40 from the left and right chambers 35 to the inner side airbag portion 22 is formed.

[0050] ​Further, at the top chamber 36 side in the rear surface portion 28 (head restraint surface) of the inner airbag portion 22, a protruding portion 29 protruding toward the rear side compared to the front-rear chamber 34 side in the rear surface portion 28 (head restraint surface) is integrally formed when viewed from above. The protruding portion 29 protrudes in a substantially "V" shape when viewed from above, and a surface thereof opposite to the front-rear chamber 34 is an inclined surface 29A disposed obliquely with respect to the front-rear direction. Further, the length of the inner airbag portion 22 in the front-rear direction excluding the protruding portion 29 is longer than the length in the seat width direction when viewed from above.

[0051] Next, the operation of the airbag device 30 according to the first embodiment configured as described above will be described.

[0052] When the detection device detects that the vehicle has undergone a front surface collision, the inflator 18 operates, and gas is instantaneously ejected from the inside of the airbag main body 32. When the gas is ejected into the inside of the airbag main body 32, the housing portion 20 is ruptured by the deployment of the airbag main body 32 (by being pressed from the inside by the airbag main body 32).

[0053] Further, the outer airbag portion 33 and the inner airbag portion 22 of the airbag main body 32 are deployed from the housing portion 20 toward the front side through the left side of the head Ph of the occupant P (a gap between the head Ph of the occupant P on the side window glass side and the head of the occupant on the center seat side, not shown).

[0054] That is, when the front-rear chamber 34 of the outer airbag portion 33 is inflated and deployed at the left side of the head Ph of the occupant P, the gas flows from the front side end portion of the front-rear chamber 34 into the left-right chambers 35, and the left-right chambers 35 are inflated and deployed toward the inside in the seat width direction, and are disposed at the front side of the face of the occupant P.

[0055] Further, the gas further flows from the left-right chambers 35 into the top chamber 36, and the top chamber 36 is deployed from the seat width direction inside end portion of the left-right chambers 35 toward the rear side, and is disposed at the right side of the head Ph of the occupant P. At this time, the position of the top chamber 36 is limited by the tether 38 so as not to be too far from the front-rear chamber 34.

[0056] Further, when the gas flows into the left-right chambers 35, the gas flows from the left-right chambers 35 into the inner airbag portion 22 through the inflow port 40, and the inner airbag portion 22 is inflated and deployed between the front-rear chamber 34 and the left-right chambers 35 and the top chamber 36.

[0057] Here, the rear surface portion 28 of the inner airbag portion 22 is provided as a head restraint surface that restrains the head Ph of the occupant P. That is, the front surface portion 25 and the left and right side portions 24 and 26 of the inner airbag portion 22 having the head restraint surface are covered by the outer airbag portion 33.

[0058] Therefore, when the head restraint surface (the rear surface portion 28) of the inner airbag portion 22 is pressed toward the front side, the inner airbag portion 22 can receive a reaction force from the outer airbag portion 33 (in particular, the rear surface of the left and right chambers 35 opposite to the front surface portion 25 becomes a reaction surface). Thus, the head Ph of the occupant P seated on the vehicle seat 10 can be restrained by the inner airbag portion 22 while being pressed toward the front side of the inner airbag portion 22.

[0059] That is, it is possible to restrain the case where the amount of movement of the head Ph of the occupant P toward the front side is smaller than the amount of movement of the chest of the occupant P toward the front side determined by the restraining force of the seat belt, at the time of head restraint of the occupant P. In other words, it is possible to make the stroke of the head Ph of the occupant P toward the front side longer, and thus it is possible to restrain the tensile load acting on the head Ph of the occupant P lower (it is possible to obtain a low load / high stroke F-S characteristic). Thus, it is possible to restrain the inclination of the neck of the occupant P.

[0060] Further, since the front-rear chamber 34 and the tip chamber 36 are connected together by the tether 38, the tip chamber 36 is difficult to move in a direction away from the front-rear chamber 34. Thus, it is possible to restrain the case where the head Ph of the occupant P is pulled out of the airbag main body 32 (the inner airbag portion 22 and the outer airbag portion 33).

[0061] Further, when viewed from above, a protruding portion 29 protruding toward the rear side compared to the front-rear chamber 34 side is formed at the tip chamber 36 side in the head restraint surface (the rear surface portion 28) of the inner airbag portion 22. Therefore, when the head restraint of the occupant P by the inner airbag portion 22 is performed, the head Ph of the occupant P is difficult to be pulled out toward the tip chamber 36. That is, it is possible to more effectively restrain the case where the head Ph of the occupant P is pulled out of the airbag main body 32.

[0062] Further, the surface of the protruding portion 29 opposite to the front-rear chamber 34 becomes an inclined surface 29A arranged obliquely with respect to the front-rear direction. Therefore, when the head Ph of the occupant P presses the inclined surface 29A, it is possible to generate a counteracting torque at the rear end portion of the outer airbag portion 33 to the rotation torque that rotates the outer airbag portion 33 in a direction away from the head Ph of the occupant P. Thus, it is possible to further restrain the case where the head Ph of the occupant P is pulled out of the airbag main body 32.

[0063] Furthermore, when viewed from above, the length of the inner airbag section 22 in the fore-aft direction, excluding the protrusion 29, is set to be longer than its length in the seat width direction. Therefore, compared to a case where the length of the inner airbag section 22 in the fore-aft direction, excluding the protrusion 29, is set to be shorter than its length in the seat width direction, a longer forward head travel distance for occupant P can be ensured. Thus, posterior head tilt of occupant P can be more effectively suppressed.

[0064] (Modified example)

[0065] In addition, such as Figure 4 As shown, the tether 38 can also be configured as a tether 39 that is roughly "Y" shaped when viewed from above. That is, the tether 39 can also be configured such that one end 39A is sewn onto the top part (rear end) of the upper end of the top chamber 36, and the other end 39B on the front side and the other end 39C on the rear side are sewn onto the middle part of the upper end of the front and rear chambers 34, respectively.

[0066] Therefore, it is possible to more effectively prevent the head Ph of occupant P from exiting the airbag body 32. That is, if a straight tether 38 is used to connect the top chamber 36 and the front and rear chambers 34, then when the head of occupant P is restrained, the front and rear chambers 34 may exit from the part where the tether 38 is installed ( Figure 2 The other end 38B of the tether 38 shown bends outward in the direction of seat width, so that the head Ph of the occupant P may come out of the airbag body 32.

[0067] In this case, when a tether 39 is formed into a roughly "Y" shape when viewed from above, the front end 39B and the rear end 39C of the tether 39 are installed on the upper ends of the front and rear chambers 34 at a distance apart in the front-rear direction. This allows the tension of the tether 39 to be dispersed, thereby suppressing the bending of the front and rear chambers 34. As a result, it is possible to suppress the possibility of the occupant P's head Ph exiting from the airbag body 32.

[0068] Furthermore, preferably, the other end 39C of the tether 39 is installed as far as possible on the rear side of the front and rear chambers 34. This further suppresses the possibility of bending of the front and rear chambers 34. In addition, the tether 39 is not limited to being formed in a roughly "Y" shape when viewed from above using a single piece of fabric, but can also be formed by sewing two straight pieces of fabric together, as shown in the figure, in a roughly "Y" shape when viewed from above.

[0069] <Second Implementation>

[0070] Next, the airbag device 30 according to the second embodiment will be described. Also, the same symbols are assigned to portions equivalent to those of the above-described first embodiment, and detailed description (including common effects) will be appropriately omitted.

[0071] As shown in FIG. 6, the airbag main body 32 of the airbag device 30 according to the second embodiment differs from the above-described first embodiment only in that it is provided as an inboard airbag portion 42 equivalent to a so-called driver seat side airbag, instead of the inboard airbag portion 22, and an inflow port 40 is formed on the top chamber 36, instead of being formed on the left and right chambers 35. Figure 5 This inboard airbag portion 42 is formed in a circular shape in side view, and in a substantially elliptical shape having a predetermined thickness in the seat width direction in plan view. Also, the inboard airbag portion 42 is obliquely arranged with respect to the front-rear direction in such a manner that the rear side end portion thereof is distanced from the front-rear chamber 34.

[0072] According to the inboard airbag portion 42 of this structure, the head Ph of the occupant P is restrained in a manner of being sandwiched by the front-rear chamber 34 of the outboard airbag portion 33 and the head restraint face 42A of the inboard airbag portion 42. Thereby, it is possible to suppress the head Ph of the occupant P from escaping from the airbag main body 32.

[0073] Further, since the head Ph of the occupant P can pass between the front-rear chamber 34 of the outboard airbag portion 33 and the inboard airbag portion 42 and move toward the front side, it is possible to make the head Ph of the occupant P travel a long distance. Therefore, it is possible to suppress the tensile load acting on the head Ph of the occupant P to be low, and thereby it is possible to suppress the occupant P's neck from leaning backward.

[0074] <Third Embodiment>

[0075] Next, the airbag device 30 according to the third embodiment will be described. Also, the same symbols are assigned to portions equivalent to those of the above-described second embodiment, and detailed description (including common effects) will be appropriately omitted.

[0076] As shown in FIG. 7, the airbag main body 32 of the airbag device 30 according to the third embodiment differs from the above-described second embodiment only in that it is provided as an inboard airbag portion 42 equivalent to a so-called driver seat side airbag, instead of the inboard airbag portion 22, and an inflow port 40 is formed on the top chamber 36, instead of being formed on the left and right chambers 35.

[0077] Figure 6 ​As shown, the airbag body 32 of the airbag device 30 according to the third embodiment differs from the second embodiment in the following aspects: the inner airbag portion 42 in the second embodiment is arranged along the front-rear direction (and is not arranged at an angle relative to the front-rear direction); the inlet 40 is formed on the left and right chambers 35 instead of the top chamber 36; and the vent 44 for venting gas is formed on the inner airbag portion 42.

[0078] Vent 44 is formed at an appropriate position in, for example, the upper surface portion of the inner airbag portion 42, and its opening area S2 is set to be the same as the opening area S1 of the inlet 40 for allowing gas to flow from the outer airbag portion 33 to the inner airbag portion 42 (see reference). Figure 3 This is relatively large (for example, it is set as S2 = S1 × 2).

[0079] The inner airbag section 42, with its vent 44 of such a size, can reduce the internal pressure of the inner airbag section 42 when the occupant P's head is restrained, thereby making the inner airbag section 42 more flexible. As a result, since the occupant P's head Ph can travel a longer distance forward, it is possible to suppress the possibility of the occupant P's head Ph dislodging from the airbag body 32, and it is also possible to suppress the backward tilting of the occupant P's neck.

[0080] <Fourth Implementation>

[0081] Finally, the airbag device 30 according to the fourth embodiment will be described. Furthermore, the same symbols are used for parts equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0082] like Figures 7A to 8B As shown, the airbag body 32 of the airbag device 30 according to the fourth embodiment differs from the first embodiment in the following aspects: a variable vent 46 for venting gas is provided on the inner airbag part 22, and a one-way valve 50 is provided on the inlet 40 for allowing gas to flow from the outer airbag part 33 to the inner airbag part 22.

[0083] The one-way valve 50 is configured to allow gas to flow in while it is flowing from the outer airbag section 33 to the inner airbag section 22. Furthermore, the one-way valve 50 is configured to close when the flow of gas from the outer airbag section 33 to the inner airbag section 22 stops, thereby restricting the outflow of gas from the inner airbag section 22 to the outer airbag section 33.

[0084] The variable vent hole 46 is constituted by a circular-shaped vent hole 47 formed on the upper surface portion 23 of the front and rear chamber 34 side and the rear surface portion 28 side of the inboard airbag portion 22, and a cover member 48 that closes the vent hole 47 from the inside at the time of the inflation and deployment of the inboard airbag portion 22 (when the gas flows from the left and right chambers 35 of the outboard airbag portion 33 to the inboard airbag portion 22), and opens the vent hole 47 at the time of the head restraint of the occupant P.

[0085] The cover member 48 is, for example, a cloth member that extends in the front and rear direction by a predetermined width (a width capable of closing the vent hole 47), and is constituted by the same base cloth as the inboard airbag portion 22. Also, the front and rear direction one end portion and the other end portion of this cover member 48 are respectively attached to the upper surface portion 23 of the front and rear chamber 34 side and the rear surface portion 28 side (both sides in the front and rear direction of the vent hole 47) of the inboard airbag portion 22 by sewing or the like.

[0086] According to the inboard airbag portion 22 that adopts this structure, at the time of the inflation and deployment at which the gas flows from the outboard airbag portion 33, the one-way valve 50 opens to set the internal pressure of the inboard airbag portion 22 to be the same as the internal pressure of the outboard airbag portion 33. Due to this, since a tension toward the outside in the front and rear direction acts on the cover member 48, the vent hole 47 is closed from the inside by this cover member 48.

[0087] Also, since the inflow of the gas from the outboard airbag portion 33 is in a stopped state at the time of the head restraint of the occupant P, the one-way valve 50 is set to a closed state, so the internal pressure of the outboard airbag portion 33 is maintained in a high pressure state, and further the inboard airbag portion 22 is pressed from the rear surface portion 28 (head restraint surface) side toward the front by the head Ph of the occupant P. That is, the upper surface portion 23 of the front and rear chamber 34 side of the inboard airbag portion 22 is deformed toward the front. Due to this, the tension toward the outside in the front and rear direction that acts on the cover member 48 is released, so the front and rear direction central portion of this cover member 48 is deflected toward the lower side to open the vent hole 47.

[0088] Therefore, at the time of the head restraint of the occupant P, it is possible to reduce the internal pressure of the inboard airbag portion 22 while maintaining the internal pressure of the outboard airbag portion 33 in a high pressure state, so it is possible to make the inboard airbag portion 22 soft. Due to this, since it is possible to make the head Ph of the occupant P travel long to the front, it is possible to suppress the occupant P from being ejected from the airbag main body 32, and it is possible to suppress the occupant P from leaning back at the neck.

[0089] While the seat-mounted type airbag device 30 according to the present embodiment has been described above based on the drawings, the seat-mounted type airbag device 30 according to the present embodiment is not limited to the illustrated content, and can be appropriately designed with variations within the scope of the gist of the present disclosure. For example, the seat-mounted type airbag device 30 according to the present embodiment can also appropriately combine the structures in each of the embodiments (including the variations).

[0090] Further, the opening and closing structure of the cover member 48 constituting the variable vent hole 46 is not limited to the above-described structure. The cover member 48 can be provided in any structure as long as it is closed when the air flow flows from the outboard airbag portion 33 (the left and right chambers 35) to the inboard airbag portion 22, and is opened (opened by the head Ph of the occupant P pressing the inboard airbag portion 22 to the front side) when the head of the occupant P is restrained.

[0091] Symbol Explanation

[0092] 22… inboard airbag portion;

[0093] 28… rear surface portion (head restraint surface);

[0094] 29… protruding portion;

[0095] 30… airbag device (seat-mounted type airbag device);

[0096] 32… airbag main body;

[0097] 33… outboard airbag portion;

[0098] 34… front and rear chambers;

[0099] 35… left and right chambers;

[0100] 36… top end chamber;

[0101] 38… tether;

[0102] 39… tether;

[0103] 40… inflow port;

[0104] 42… inboard airbag portion;

[0105] 44… vent hole;

[0106] 46… variable vent hole;

[0107] 50… one-way valve;

[0108] P… occupant;

[0109] Ph… head.

Claims

1. A seat-mounted airbag device, wherein, The airbag body comprises: The outer airbag unit has front and rear chambers, left and right chambers, and a top chamber, and is equipped with a tether. The front and rear chambers are propelled by gas ejected from an inflation device that operates based on detecting or predicting a vehicle collision, passing through one side of the occupant's head and extending towards the front of the seat, and are positioned on one side of the occupant's head. The left and right chambers extend inward in the width direction from the front and rear chambers towards the front of the seat and are positioned on the front side of the occupant's face. The top chamber extends inward in the width direction from the left and right chambers towards the rear of the seat and is positioned on the other side of the occupant's head. The tether connects the front and rear chambers and the top chamber. The inner airbag section is configured to deploy between the front and rear chambers, the left and right chambers, and the top chamber by means of gas flowing in from the outer airbag section, and has a head restraint surface for restraining the occupant's head.

2. The seat-mounted airbag device as described in claim 1, wherein, When viewed from above, a protrusion is formed on the top chamber side of the head restraint surface of the inner airbag portion, which protrudes toward the rear of the seat compared to the front and rear chamber sides.

3. The seat-mounted airbag device as described in claim 2, wherein, When viewed from above, the length of the inner airbag portion in the fore-and-aft direction of the seat, excluding the protrusion, is set to be longer than the length in the width direction of the seat.

4. The seat-mounted airbag device as described in claim 1, wherein, When viewed from above, the inner airbag portion is formed into a generally elliptical shape with a predetermined thickness in the width direction of the seat, and is tilted relative to the fore-and-aft direction of the seat so that its rear end is moved away from the front and rear chambers.

5. The seat-mounted airbag device as described in any one of claims 1 to 4, wherein, A vent is formed on the inner side of the airbag to allow the gas to escape. The opening area of ​​the vent is set to be larger than the opening area of ​​the inlet for allowing the gas to flow from the outer airbag section to the inner airbag section.

6. The seat-mounted airbag device as described in any one of claims 1 to 4, wherein, A one-way valve is provided at the inlet for allowing the gas to flow from the outer airbag section to the inner airbag section. The one-way valve allows the gas to flow from the outer airbag section to the inner airbag section and restricts the gas to flow from the inner airbag section to the outer airbag section. A variable vent is provided on the inner airbag section. The variable vent is closed when gas is flowing from the outer airbag section to the inner airbag section and is opened when the occupant's head is restrained.

7. The seat-mounted airbag device as described in any one of claims 1 to 4, wherein, The tether is formed into a roughly Y-shaped form when viewed from above, with one end mounted on the top chamber, and the other end of the tether, which is spaced apart in the front and rear directions of the seat, is respectively mounted on the front and rear chambers.

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