Passenger protection device

Abstract

A rider protection device is disclosed that can suppress the occurrence of the submarine phenomenon and secure initial waist restraint performance. The passenger protection device (30) is installed inside or below the seat cushion (2) of the vehicle seat (100) and is equipped with an airbag cushion (32) that can be inflated and deployed to push up the seat surface (26) of the seat cushion (2), and an inflator (34) that supplies gas for inflatation and deployment to the inside of the airbag cushion (32) in case of a vehicle emergency. The airbag cushion (32) has an inflatation and deployment section (40) that is inflated and deployed by gas from the inflator (34), and an exhaust vent section (42) installed to protrude from the periphery (32a) of the airbag cushion (32). The inflated and deployed airbag cushion (32) is configured such that when a load is applied to the inflatation and deployment section (40), the exhaust vent section (42) opens to communicate the inside of the inflatation and deployment section (40) with the outside.

Description

Technology Field

[0001] The present invention relates to a passenger protection device installed inside or below the seat cushion of a vehicle seat. Background Technology

[0002] Generally, for a passenger seated in a vehicle, the shoulder belt of the seat belt is positioned diagonally across the front of the passenger's chest, and the wrap belt is positioned across the front of the passenger's waist. In the event of a vehicle collision, the seat belt restricts the passenger's movement. However, particularly in the event of a frontal collision, there is a possibility of a "submarine effect" occurring, where the passenger's body intrudes under the wrap belt. The submarine effect is undesirable because the wrap belt can compress the passenger's abdomen.

[0003] As a countermeasure against the submarine phenomenon, a occupant protection device is known in which an airbag is installed inside the seat cushion of a vehicle seat. For example, Patent Document 1 describes a method in which, upon a frontal collision of a vehicle, an airbag inside the vehicle seat is instantaneously inflated to push up the front portion of the seat cushion, thereby restraining the occupant's waist and inhibiting the occupant's forward movement. Additionally, Patent Document 2 describes a method in which a gas release hole is formed in the airbag. Prior art literature

[0004] Patent Document 1: Japanese Patent Publication No. 2007-118820 Patent Document 2: Japanese Patent Publication No. 2006-327577 The problem to be solved

[0005] However, in Patent Document 1, while the occupant's waist is restrained, the inside of the airbag is maintained at high pressure, and the airbag continues to push up the occupant's thigh area. Because of this, depending on the occupant's seating position, there is a possibility that the airbag will lift the occupant's waist and rotate it to the rear. This is particularly likely to occur when the occupant's center of gravity is located further back, such as in a reclining position (comfortable position) with the vehicle seat tilted back. For instance, if this phenomenon occurs, the seat belt's lap belt detaches from the occupant's ilium, resulting in a submarine effect.

[0006] On the other hand, in Patent Document 2, the occurrence of the aforementioned phenomenon or the submarine phenomenon can be suppressed because the gas inside the airbag escapes through the gas outlet. However, there is a problem in that the initial waist restraint performance is reduced because the gas inside the airbag escapes before the occupant's waist is sufficiently restrained.

[0007] The present invention aims to provide a rider protection device capable of suppressing the occurrence of the submarine phenomenon and securing initial waist restraint performance. means of solving the problem

[0008] A occupant protection device according to one embodiment of the present invention is an occupant protection device installed inside or below the seat cushion of a vehicle seat, comprising an airbag cushion capable of inflating and deploying to push up the seat surface of the seat cushion, and an inflator that supplies gas for inflating and deploying to the interior of the airbag cushion in the event of a vehicle emergency. The airbag cushion has an inflating and deploying section that inflates and deploys by gas from the inflator, and an exhaust vent section installed to protrude from the periphery of the airbag cushion. The inflated and deployed airbag cushion is configured such that when a load is applied to the inflating and deploying section, the exhaust vent section opens to communicate the interior of the inflating and deploying section with the exterior.

[0009] According to this configuration, for example, when a passenger is seated in a vehicle seat, it operates as follows. In the event of a vehicle emergency, the expansion expansion unit, supplied with gas from the inflator, expands and pushes up the seat surface of the seat cushion. During the initial stage of this expansion, the exhaust vent is not open, so the internal pressure of the expansion expansion unit is retained and supported. Therefore, it becomes possible to secure initial lumbar restraint performance. After restraint, a load (e.g., a reaction force due to the upward push) acts on the expansion expansion unit. When the load is applied, the internal pressure of the expansion expansion unit becomes higher than during the initial stage of expansion; consequently, the exhaust vent, which was closed during the initial stage, opens, and the internal pressure of the expansion expansion unit decreases. Consequently, further upward pushing of the passenger's lumbar area is suppressed, and the occurrence of the submarine phenomenon can be prevented. Additionally, soft restraint using the stroke (contraction due to the decrease in internal pressure) by the expansion expansion unit becomes possible.

[0010] In various embodiments of the present invention, the airbag cushion may have a bubble panel constituting an inflation / deployment section and a bubble panel extension section installed continuously from the bubble panel to constitute an exhaust vent section. Additionally, the bubble panel extension section may have an upper extension panel and a lower extension panel facing each other in the vertical direction, and an exhaust port formed between the upper extension panel and the lower extension panel or formed on at least one side of the upper extension panel and the lower extension panel. Furthermore, when the airbag cushion inflates / deploys, the bubble panel extension section may be configured such that the upper extension panel and the lower extension panel are in close contact with each other to close the exhaust port until the load is applied to the inflation / deployment section, and the close contact between the upper extension panel and the lower extension panel is released when the load is applied to the inflation / deployment section, thereby opening the exhaust port.

[0011] Viewing the above form from a different perspective, in another embodiment of the present invention, the exhaust vent may have an exhaust port and a surrounding portion of the exhaust port, and the inflated airbag cushion may be configured such that the surrounding portions are in close contact with each other to close the exhaust port until the load is applied to the inflated portion, and then the close contact of the surrounding portions is released so that the exhaust port is opened when the load is applied to the inflated portion.

[0012] In general, in an airbag cushion that inflates and deploys, the membrane surface tension increases as the internal pressure increases. According to the above configuration, when the airbag cushion inflates and deploys, prior to the application of a load, the inflated and deployed section is in a stage between the initial stage of inflatation and the subsequent stage of normal deployment (which may also include the stage where inflatation and deployment are completed). The internal pressure in this stage maintains the exhaust vent section (the upper extension panel and the lower extension panel or surrounding area) in a state of close contact or near close contact in relation to the membrane surface tension. In this way, the exhaust port of the exhaust vent section is closed to secure the initial waist restraint performance. Meanwhile, as a load is applied, the internal pressure of the inflated and deployed section becomes higher than the internal pressure in the above-described stage, while the membrane surface tension in the vicinity of the exhaust vent section does not rise significantly compared to other parts (the part where the load is applied) (i.e., the increase in internal pressure is relatively greater than the increase in membrane surface tension). Accordingly, the relative balance relationship between internal pressure and membrane surface tension is reversed, and the aforementioned tight or near-tight state is resolved, causing the exhaust port of the exhaust vent section to open. As a result, the internal pressure of the expansion / development section is reduced, and additional upward thrust of the occupant's waist is suppressed. Brief explanation of the drawing

[0013] FIG. 1A is a perspective view showing the external shape of a vehicle seat on which a passenger protection device according to an embodiment is installed. FIG. 1B is a perspective view showing the internal frame structure of the vehicle seat of FIG. 1A. FIG. 2 is a plan view showing an airbag cushion of a occupant protection device according to an embodiment before being installed in the seat pan of a vehicle seat. FIG. 3 is a cross-sectional view of a occupant protection device according to an embodiment after being installed on the seat pan of a vehicle seat. FIG. 3A is a cross-sectional view of a passenger protection device relating to a modified embodiment, showing the exhaust vent portion being sandwiched between the folded layers of the folded expansion expansion portion. FIG. 4A is a schematic cross-sectional view showing the state of an inflated airbag cushion of a occupant protection device according to an embodiment before a load is applied to the inflated / deployed part. FIG. 4B is a schematic cross-sectional view showing the state of an inflated airbag cushion of a occupant protection device according to an embodiment when a load is applied to the inflated / deployed part. FIG. 5 is a graph showing the change in internal pressure of each airbag cushion of the occupant protection device according to the embodiment and the occupant protection device according to the comparative example. FIG. 6 is a diagram showing the relationship between the occupant protection device and the occupant in a comparative example (no exhaust vent), where (a) is a normal state, (b) is an initial state (when restrained) during a vehicle emergency, and (c) is a schematic diagram showing the middle or later state (after restraint) during a vehicle emergency. FIG. 7 is a diagram showing the relationship between a occupant protection device and an occupant in a comparative example (with a circular vent hole), where (a) is a normal state, (b) is an initial state (when restrained) in a vehicle emergency, and (c) is a schematic diagram showing a mid-stage or late state (after restraint) in a vehicle emergency. FIG. 8 is a diagram showing the relationship between a occupant protection device and an occupant according to an embodiment, wherein (a) is a normal state, (b) is an initial state (when restrained) during a vehicle emergency, and (c) is a schematic diagram showing a middle or later state (after restraint) during a vehicle emergency. FIG. 9 is a cross-sectional view of a passenger protection device according to a second embodiment. FIG. 10 is a cross-sectional view of a passenger protection device according to a third embodiment. FIG. 11 is a plan view showing an airbag cushion of a passenger protection device according to a fourth embodiment. FIG. 12 is a plan view showing an airbag cushion of a passenger protection device according to the fifth embodiment. FIG. 13 is a perspective view showing the airbag cushion of the passenger protection device according to the 6th embodiment in an inflated and deployed state. FIG. 14 is a plan view showing the side panels of the airbag cushion of FIG. 13, where (A) shows one side panel and (B) shows the other side panel. FIG. 15 is a plan view showing an airbag cushion of a passenger protection device according to the seventh embodiment. FIG. 16 is a plan view showing an airbag cushion of a passenger protection device according to the eighth embodiment. Specific details for implementing the invention

[0014] A occupant protection device according to a suitable embodiment of the present invention will be described with reference to the attached drawings. In this specification, up and down, left and right, and front and back are defined as follows. When an occupant is seated in a seat (vehicle seat) in a regular posture, the direction the occupant is facing is referred to as the front, and the opposite direction is referred to as the rear; when indicating a coordinate axis, it is called the front-back direction. In addition, when an occupant is seated in a vehicle seat in a regular posture, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction; when indicating a coordinate axis, it is called the left-right direction. At the same time, when an occupant is seated in a regular posture, the direction of the occupant's head is referred to as the up direction, and the direction of the occupant's waist is referred to as the down direction; when indicating a coordinate axis, it is called the up-down direction.

[0015] As shown in FIGS. 1A and 1B, the vehicle seat (100) is equipped with a seat back (1) that supports the back of the occupant, a seat cushion (2) on which the occupant sits, and a headrest (3) that supports the head of the occupant. The vehicle seat (100) may be, for example, a driver's seat or a passenger seat, but may also be a rear seat.

[0016] Inside the seat back (1) and seat cushion (2), a seat frame (10) and a seating frame (20) forming the skeleton of the seat are installed, respectively. The seat frame (10) and the seating frame (20) are made by processing metal parts or hardened resin and are connected to each other via a reclining mechanism (4). The seating frame (20) has a pair of side frames (22, 22) spaced apart from each other on the left and right sides, and a seat pan (24) (see FIG. 3) is installed between the pair of side frames (22, 22). The seat cushion (2) has a seat pad made of, for example, urethane foam covering the surface and surroundings of the seating frame (20), and a seat cover made of leather or fabric covering the surface of the seat pad. The upper surface of the seat cover forms the surface on which the occupant sits, that is, the seat surface (26) of the seat cushion (2).

[0017] The occupant protection device (30) is installed inside or below the seat cushion (2). For example, the occupant protection device (30) is installed inside the seat cushion (2) and covered by a seat cover. In this case, the occupant protection device (30) may be installed on the upper surface of the seat pan (24). Alternatively, if the seat pan (24) is not installed, it may be installed on the seating frame (20). In another example, the occupant protection device (30) is installed not inside the seat cushion (2) but on the lower part of the seat cushion (2). In this case, for example, the occupant protection device (30) is installed on a bracket fixed to the vehicle seat (100) on the lower part of the seat cushion (2). Below, an example in which the occupant protection device (30) is installed on the upper surface of the seat pan (24) will be described.

[0018] As shown in FIGS. 2 and 3, the passenger protection device (30) comprises an inflatable airbag cushion (32) and an inflator (34) that supplies gas for inflatation and deployment to the inside of the airbag cushion (32) in the event of a vehicle emergency. A vehicle emergency is, for example, a frontal collision of a vehicle. Also, in FIG. 2, the inflator (34) is omitted.

[0019] The inflator (34) is electrically connected to the vehicle side (ECU). For example, the inflator (34) receives a signal from the vehicle side (ECU) detecting the impact during a frontal collision of the vehicle, operates, and instantaneously supplies gas toward the airbag cushion (32). Various materials can be used for the inflator (34), such as a gas generator, compressed gas, or a mixture of both. For example, the inflator (34) has an ignition device at the open end of a cylindrical body with a bottom. By igniting the gas generator inside the cylindrical body with this ignition device, gas is generated, and gas for expansion is supplied into the airbag cushion (32) through multiple ejection holes on the circumferential surface of the cylindrical body.

[0020] The airbag cushion (32) has an expansion expansion section (40) that expands and expands by gas from an inflator (34), and an exhaust vent section (42) installed to protrude from the periphery (32a) of the airbag cushion (32).

[0021] The expansion / deployment section (40) constitutes most of the airbag cushion (32). The capacity when the expansion / deployment section (40) is expanded / deployed is, for example, about 4 to 6 liters. The exhaust vent section (42) is continuous with the expansion / deployment section (40) so as to protrude from one end of the expansion / deployment section (40). Here, the exhaust vent section (42) is located on the front side in the front-rear direction of the vehicle seat (100) and is installed to protrude forward from the center of the front end of the expansion / deployment section (40). However, in other embodiments, the exhaust vent section (42) may be protruded from another location of the expansion / deployment section (40), such as being located on the rear side in the front-rear direction of the vehicle seat (100).

[0022] The expansion expansion section (40) and the exhaust vent section (42) are each connected internally. The interior of the expansion expansion section (40) is a closed space except for the connecting portion (44) with the interior of the exhaust vent section (42). The exhaust vent section (42) has an exhaust port (46) that connects the interior of the exhaust vent section (42) to the outside. The exhaust port (46) is located, for example, on the opposite side of the connecting portion (44) in the exhaust vent section (42). The exhaust port (46) is normally open. As described later, the exhaust port (46) is configured to be closed during the initial stages of a vehicle emergency and then opened.

[0023] The exhaust vent section (42) is configured such that the bottom section (42a) on the side of the periphery (32a) of the airbag cushion (32) is narrower than the front section (42b) of the exhaust vent section (42). In accordance with this configuration, the length in the left-right direction inside the exhaust vent section (42) is shorter at the bottom section (42a) than at the front section (42b). Here, the exhaust vent section (42) is configured to gradually narrow in width from the front section (42b) to the bottom section (42a), and in accordance with this, the interior of the exhaust vent section (42) is also gradually narrowed in width from the front section (42b) to the bottom section (42a). A communication section (44) is located at the bottom section (42a), and an exhaust port (46) is located at the front section (42b).

[0024] The airbag cushion (32) has a bubble panel (50) constituting the expansion / deployment section (40) and a bubble panel extension (52) constituting the exhaust vent section (42). The bubble panel extension (52) is installed continuously from the bubble panel (50). The bubble panel extension (52) is formed more widely at the leading edge of the bubble panel extension (52) than at the boundary with the bubble panel (50). This is related to the fact that, as described above, the exhaust vent section (42) is configured such that the bottom part (42a) is narrower than the leading edge (42b).

[0025] From a different perspective, it is also possible to understand that the airbag cushion (32) has a constricted structure (220) in the middle of the bubble panel extension (52). "Middle of the bubble panel extension (52)" refers to the middle or end of the bubble panel extension (52). In the constricted structure, for example, as shown in FIG. 2, a portion of the airbag cushion (32) in the longitudinal direction (here, the front-rear direction) in a flatly unfolded state is narrower than other parts (constricted portion). Here, the constricted structure (220) is installed so that the constricted portion is formed at the bottom part (42a) of the exhaust vent (42), that is, at the end of the bubble panel extension (52).

[0026] The bubble panel (50) has an upper bubble panel (50a) and a lower bubble panel (50b) facing each other in the vertical direction. Likewise, the bubble panel extension (52) has an upper extension panel (52a) and a lower extension panel (52b) facing each other in the vertical direction. The upper extension panel (52a) is installed continuously from the upper bubble panel (50a), and the lower extension panel (52b) is installed continuously from the lower bubble panel (50b). Additionally, an exhaust port (46) is formed between the upper extension panel (52a) and the lower extension panel (52b). In other words, the exhaust vent section (42) forms the surrounding area (53) of the exhaust port (46) by the upper extension panel (52a) and the lower extension panel (52b).

[0027] The upper bubble panel (50a) and the lower bubble panel (50b) may be panels divided into two pieces (each being an individual panel) or may be formed by folding a single panel back and overlapping it vertically. The same applies to the upper extension panel (52a) and the lower extension panel (52b).

[0028] An example of folding a single panel is described. First, a single panel made of non-woven fabric or the like is folded back at the center of its length direction, and the folded parts are overlapped vertically. Then, the upper part of the overlapped upper air bubble panel (50a) and upper extension panel (52a), and the lower part of the lower air bubble panel (50b) and lower extension panel (52b), are each sealed at the core (54). However, the seal is not made at the location of the exhaust port (46). Through such sealing, an air chamber is partitioned and formed inside the space between the upper air bubble (upper air bubble panel (50a) and upper extension panel (52a)) and the lower air bubble (lower air bubble panel (50b) and lower extension panel (52b)) located further inside the core (54). As gas from the inflator (34) is supplied to this chamber, the expansion expansion section (40) expands and expands into a pocket shape.

[0029] The airbag cushion (32) has, for example, a front installation point (60) and a rear installation point (62a, 62b) as installation points for the seat pan (24) of the vehicle seat (100). The front installation point (60) may also serve as an installation point for installing the inflator (34) on the vehicle seat (100) side. For example, if the cylindrical body with a bottom is used as the inflator (34), the axial direction of the cylindrical body is aligned with the left and right directions and accommodated inside the expansion / deployment section (40). Then, a pair of left and right stud bolts (34a) protruding from the outer circumference of the cylindrical body are protruded to the outside of the airbag cushion (32) (below the lower bubble panel (50b)) and fastened to the seat pan (24) by means of nuts. By doing so, the inflator (34) and the airbag cushion (32) are fastened together to the seat pan (24) by means of the stud bolts (34a) and nuts. The part connected together forms the front installation point (60).

[0030] The rear installation points (62a, 62b) are installed further back than the front installation point (60) in the front-rear direction of the vehicle seat (100). The rear installation points (62a, 62b) are installed at the rear corner of the periphery (32a) of the airbag cushion (32) and are spaced apart from each other in the left-right direction. The rear installation points (62a, 62b) are holes where, for example, a fixing device (70) is used. The rear installation points (62a, 62b) are formed on the periphery (50c) of the upper bubble panel (50a) and the lower bubble panel (50b) and are located further outward than the seam (54). Therefore, the rear installation points (62a, 62b) are installed in the non-inflated part of the airbag cushion (32), rather than the inflated deployment part (40).

[0031] The airbag cushion (32) installed on the seat pan (24) is folded in at least a portion before inflation and deployment. For example, the inflation and deployment section (40) is folded between the front installation point (60) and the rear installation point (62a, 62b). For example, the inflation and deployment section (40) has several back-folding sections (64) that overlap each other in the vertical direction by being folded in an accordion shape on the front side. In other embodiments, the inflation and deployment section (40) may be folded in a shape other than an accordion shape (e.g., a rolling shape) or a combination of several shapes. The exhaust vent section (42) may be installed so as to hang down on the front side of the back-folding section (64) or installed so as to be folded.

[0032] Alternatively, as shown in the modified example in FIG. 3A, the exhaust vent portion (42) may be inserted between the folded layers of the folded expansion expansion portion (40). For example, the exhaust vent portion (42) may be folded backward starting from the bottom portion (42a) and the front portion (42b) may be inserted between several back-folded portions (64) of the expansion expansion portion (40). In addition, other installation methods of the exhaust vent portion (42) will be described later using FIG. 9 and FIG. 10. In the installed state of the airbag cushion (32), the upper extension panel (52a) and the lower extension panel (52b) have their inner surfaces in contact with each other.

[0033] In addition, in another embodiment, the front installation point (60) may also be a hole using a fixing device, just like the rear installation point (62a, 62b). Also, the location where the inflator (34) is installed may be the rear side of the airbag cushion (32) so as to be away from the exhaust port (46). By doing this, it is possible to prevent gas from the inflator (34) from leaking out of the exhaust port (46) during the initial stage when the inflator (34) is operated.

[0034] Next, the state progression of the inflated airbag cushion (32) is described with reference to FIGS. 4A and FIG. 4B. FIG. 4A shows the state of the inflated deployment unit (40) after inflating and before a load is applied. FIG. 4B shows the state of the inflated deployment unit (40) after inflating and when a load is applied.

[0035] As shown in FIG. 4A, when the airbag cushion (32) receives gas supply from the inflator (34), the expansion expansion section (40) expands upward so that the fold line of the back-fold section (64) is resolved. In the expanded airbag cushion (32), as indicated by the arrow (80), the expansion expansion section (40) is pulled by internal pressure, and membrane surface tension is generated and rises. Accordingly, the exhaust port (46) is closed. That is, the internal pressure of the airbag cushion (32) in relation to the increased membrane surface tension brings the upper extension panel (52a) and the lower extension panel (52b) (the surrounding area (53) of the exhaust port (46)) into close contact with each other and closes the exhaust port (46). Accordingly, the gas inside the expansion expansion section (40) is prevented from leaking from the exhaust vent section (42).

[0036] As shown in FIG. 4B, when a load (F) is applied to the expansion development section (40), the expansion development section (40) deforms. For example, when a load (F) is applied from the outside of the expansion development section (40) toward the inside of the expansion development section (40), the internal pressure of the expansion development section (40) increases compared to the initial expansion development, while the membrane surface tension near the exhaust vent section (42) does not rise significantly, causing the exhaust vent section (42), which was in a tight state during the initial expansion development, to open. That is, the tightness between the upper extension panel (52a) and the lower extension panel (52b) (the area (53) around the exhaust port (46)) is released, and the exhaust port (46) is opened. As a result, the inside of the expansion development section (40) communicates with the outside, and gas inside the expansion development section (40) leaks out from the exhaust vent section (42).

[0037] The principle of opening the exhaust vent section (42) is explained in more detail as follows. In general, in an airbag cushion that expands evenly, the membrane surface tension increases as the internal pressure increases. This membrane surface tension also changes due to the radius of curvature or the deformation state of the airbag cushion itself (for example, due to the deformation of the airbag cushion, the direction of the membrane surface tension changes up, down, left, and right before and after constraining). The location where the exhaust vent section (42) is located is away from the location where the load (F) is applied, and in this location, the deformation caused by the load (F) on the airbag cushion itself is small, and the radius of curvature does not change significantly. For this reason, it can be assumed that even when the load (F) is applied, the membrane surface tension in the exhaust vent section (42) does not increase much compared to other parts (the part where the load (F) is applied). Meanwhile, in the expansion / deployment section (44), the internal pressure rises due to gas from the inflator (34) or deformation of the bag caused by the load (F).

[0038] Here, the internal pressure from the initial expansion phase before the load (F) is applied until normal expansion proceeds thereafter maintains the exhaust vent section (42) in a state of close contact or close contact in relation to the membrane surface tension. Accordingly, the exhaust port (46) of the exhaust vent section (42) is closed. Then, when the load (F) is applied, the internal pressure of the expansion phase (44) increases further, while, in the vicinity of the exhaust vent section (42), the membrane surface tension does not rise as much compared to other parts (where the load (F) is applied) (i.e., the rise in internal pressure is relatively greater than the rise in membrane surface tension). As a result, due to the balance relationship between the internal pressure and the membrane surface tension during expansion, the exhaust port (46) of the exhaust vent section (42), which had been closed in a close contact state since the initial expansion, is opened. That is, when a load (F) is applied, the relative balance relationship between the internal pressure of the exhaust vent (42) and the membrane surface tension is reversed, and the state of close contact or a state close to close contact is resolved, so that the exhaust port (46) is opened.

[0039] Here, the load (F) can include, for example, the reaction force when the inflated airbag cushion (32) pushes up the seat surface (26) while the passenger is seated on the vehicle seat (100). The inflated deployment unit (40) pushes up the seat surface (26) and, accordingly, lifts the passenger's thigh (for example, near the passenger's buttocks). When the inflated deployment unit (40) presses against the passenger's thigh through the seat surface (26), the force due to the weight of the seat cushion (2) and the passenger, or the inertial force of the passenger attempting to move forward, acts on the inflated deployment unit (40) as a reaction force to that pressure. The force acting at this time can be the load (F) that opens the exhaust port (46). Meanwhile, when the passenger is not in close contact with the vehicle seat (100), the load (F) does not act on the inflated deployment unit (40). Therefore, it is also possible to understand that the conditions for opening the exhaust vent (42) include when the passenger's thigh is pressed (when the waist is restrained) during vehicle emergency or passenger movement.

[0040] FIG. 5 is a graph showing the change in internal pressure of an airbag cushion over time when a passenger is seated in a vehicle seat. Curve (Y1) relates to an airbag cushion in a comparative example that does not have an exhaust vent (42), and curve (Y2) relates to an airbag cushion (32) in an embodiment that has an exhaust vent (42). Time (t1) represents the timing (when the waist area is restrained) when the inflated airbag cushion presses against the passenger's thigh. Time (t1) is, for example, 15 msec from the start of the inflatation of the airbag cushion. Up to time (t1), the internal pressure continues to rise in almost the same way in the comparative example and the embodiment.

[0041] In the comparative example shown on the curve (Y1), the internal pressure of the airbag cushion continues to rise even after time (t1) and then reaches leakage. Therefore, the airbag cushion in the comparative example continues to push up the occupant's thighs with an even higher internal pressure even after the occupant's waist is restrained.

[0042] In contrast, in the embodiment shown in curve (Y2), the rise in internal pressure of the airbag cushion (32) after time (t1) is suppressed and tends to decrease. This is because the exhaust port (46) is opened at time (t1). Therefore, the airbag cushion (32) of the embodiment enables the same initial waist restraint as the airbag cushion of the comparative example, and after the waist restraint, it can continue the waist restraint with a lower internal pressure than the airbag cushion of the comparative example.

[0043] Next, with further reference to FIGS. 6 to 8, the operation of the occupant protection device (30) according to the embodiment during a vehicle emergency is explained in comparison with the occupant protection device according to two comparative examples. FIG. 6 is an airbag cushion (32') according to a comparative example that does not have an exhaust vent section (42) (i.e., an airbag cushion representing the curve (Y1) of FIG. 5), FIG. 7 is an airbag cushion (32'') according to another comparative example that has a circular vent hole in the expansion / deployment section instead of the exhaust vent section (42) (i.e., a circular exhaust vent formed in a part of the expansion / deployment section), and FIG. 8 is an airbag cushion (32) according to the embodiment. In each figure, (a) represents the normal state, (b) represents the initial state during a vehicle emergency (when the waist is restrained), and (c) represents the middle or later state during a vehicle emergency (after restraint).

[0044] First, in a comparative example that does not have an exhaust vent (42), as shown in FIG. 6(b), the inflated airbag cushion (32') pushes up the thigh of the passenger (107) and restrains the waist of the passenger (107) through the seat surface (26). However, while restraining the waist of the passenger (107), the airbag cushion (32') is maintained at high pressure and continues to push up the thigh of the passenger (107). As a result, as indicated by the arrow (90), the airbag cushion (32') can lift the waist of the passenger (107) and rotate it to the rear. Then, as shown in FIG. 6(c), the wrap belt (105) of the seat belt may detach from the ilium (110) of the passenger (107), and a submarine phenomenon may occur in which the body of the passenger (107) infiltrates the lower side of the wrap belt (105).

[0045] In addition, in another comparative example having a circular vent hole, as shown in FIG. 7(b), the inflated airbag cushion (32'') pushes up the thigh of the passenger (107) through the seat surface (26), but the pushing force is weak compared to the comparative example of FIG. 6. This is because in the comparative example shown in FIG. 7, after the inflatation begins, the gas inside the airbag cushion (32'') leaks out through the circular vent hole, so the internal pressure is not retained. Therefore, the initial restraining force on the waist of the passenger (107) is low, and as shown by the arrow (94) in FIG. 7(c), the forward movement of the passenger (107) cannot be sufficiently restrained.

[0046] Meanwhile, in the embodiment shown in FIG. 8, the exhaust vent (42) is closed until the waist of the occupant (107) is restrained, so the initial restraint of the occupant's (107) waist is achieved in the same way as in the comparative example shown in FIG. 6 (see FIG. 8(b)). And after the waist of the occupant (107) is restrained, the exhaust vent (42) is opened, so the restraint of the occupant's waist is relaxed compared to the comparative example shown in FIG. 6. Therefore, the airbag cushion (32) is prevented from rotating the occupant's (107) waist to the rear. Accordingly, as shown in FIG. 8(c), the wrap belt (105) can be maintained in a state where it is hooked onto the iliac bone (110) of the occupant (107). In addition, the forward movement of the occupant (107) indicated by the arrow (96) is prevented. During the waist restraint shown in FIG. 8(c), a soft restraint is achieved using a stroke (contraction due to a decrease in internal pressure) by the expansion / displacement part (40).

[0047] As described above, the occupant protection device (30) according to the embodiment has an airbag cushion (32) and an inflator (34). The airbag cushion (32) has an expansion / deployment section (40) that expands and expands by gas from the inflator (34), and an exhaust vent section (42) installed to protrude from the periphery (32a) of the airbag cushion (32). The expanded airbag cushion (32) is configured such that when a load (F) is applied to the expansion / deployment section (40), the exhaust vent section (42) opens to communicate the interior of the expansion / deployment section (40) with the outside.

[0048] According to this configuration, when a vehicle emergency occurs, the expansion expansion unit (40), supplied with gas from the inflator (34), expands and expands, pushing up the seat surface of the seat cushion (2). In the initial stage of this expansion expansion, the internal pressure of the expansion expansion unit (40) is retained because the exhaust vent (42) is not open. Therefore, it becomes possible to secure the initial waist restraint performance. Then, due to the restraint of the waist, a load (F) is applied to the expansion expansion unit (40). When the load (F) is applied, the internal pressure of the expansion expansion unit (40) becomes higher than in the initial stage of expansion expansion, and the exhaust vent (42), which was in a tight state in the initial stage of expansion expansion, opens. Accordingly, the internal pressure of the expansion expansion unit (40) decreases. Therefore, it is possible to suppress further pushing up the occupant's waist and suppress the occurrence of the submarine phenomenon.

[0049] In this way, according to the embodiment, a occupant protection device (30) equipped with an airbag cushion (32) having a self-adaptive exhaust vent (42) can be provided, and the suppression of the occurrence of the submarine phenomenon and the securing of initial waist restraint performance can be achieved simultaneously.

[0050] In particular, the exhaust vent section (42) is configured so that the bottom section (42a) is narrower than the front section (42b). Because of this, the closure of the exhaust vent section (42) can be increased until the load (F) acts on the expansion section (40) in case of a vehicle emergency.

[0051] In addition, according to the modified example shown in FIG. 3A, since the exhaust vent portion (42) is sandwiched between the folded layers of the folded expansion portion (40), the leakage of gas from the exhaust port (46) of the exhaust vent portion (42) can be further suppressed during the initial expansion of the airbag cushion (32). Specifically, during the initial expansion, a slightly predetermined time is required until the membrane surface tension becomes tight, and gas may leak from the exhaust port (46) during this predetermined time. However, by arranging the exhaust vent portion (42) as described above, the flow of gas toward the exhaust vent portion (42) is suppressed structurally during the initial expansion. Therefore, gas leakage during the initial expansion is suppressed, and it becomes possible to further increase the initial waist restraint performance.

[0052] Next, other embodiments will be described. In addition, other embodiments will be described focusing on the differences from the above embodiments, and descriptions regarding components and operations common to the above embodiments will be omitted.

[0053] In the passenger protection device (30) according to the second embodiment shown in FIG. 9, in the airbag cushion (32) installed in the seat pan (24) before inflation and deployment, the exhaust vent portion (42) is folded so as to overlap the upper part of the folded inflation and deployment portion (40). For example, the exhaust vent portion (42) is folded upward starting from the bottom portion (42a) and faces all of the multiple back-fold portions (64) of the inflation and deployment portion (40), then folded backward so as to be placed on the upper part of the top back-fold portion (64), and the front portion (42b) faces backward while overlapping the upper part of the top back-fold portion (64).

[0054] In the passenger protection device (30) according to the third embodiment shown in FIG. 10, in the pre-inflation / deployment airbag cushion (32) installed in the seat pan (24), the exhaust vent portion (42) is tucked in within the folded inflation / deployment portion (40). For example, the exhaust vent portion (42) has an upper extension panel (52a) and a lower extension panel (52b) that are each folded inward starting from the bottom portion (42a) and inserted into the interior of the inflation / deployment portion (40). The inserted upper extension panel (52a) and lower extension panel (52b) are, for example, located inside one of several folded portions (64).

[0055] According to the second and third embodiments, just like the modified example shown in FIG. 3A, the flow of gas toward the exhaust vent (42) is suppressed during the initial expansion of the structure, so the leakage of gas from the exhaust port (46) of the exhaust vent (42) during the initial expansion of the airbag cushion (32) can be further suppressed.

[0056] FIG. 11 shows an airbag cushion (32) of a passenger protection device (30) according to a fourth embodiment. Here, the exhaust vent portion (42) is temporarily joined to close at least a part of the exhaust port (46), and this temporary joining is resolved by the expansion expansion portion (40) expanding.

[0057] For example, the exhaust vent section (42) is temporarily sealed by a temporary suture (200) near the base section (42a) or between the base section (42a) and the tip section (42b). The temporary suture (200) sews the upper extension panel (52a) and the lower extension panel (52b). The temporary suture (200) may completely close the exhaust port (46) in normal conditions or partially close the exhaust port (46). The sealing force of the temporary suture (200) is smaller than the sealing force of the seam (54). Because of this, when the expansion section (40) expands, the temporary suture (200) is cut due to the shape change or increased membrane surface tension caused by the expansion section (40). Therefore, even with the fourth embodiment, gas leakage from the exhaust port (46) during the initial expansion is suppressed, and it is possible to further increase the initial waist restraint performance.

[0058] FIG. 12 shows an airbag cushion (32) of a passenger protection device (30) according to a fifth embodiment. Here, the exhaust vent portion (42) has a closing portion (210) that closes the exhaust port (46), and the closing portion (210) is configured to open as the expansion / expansion portion (40) expands / expands.

[0059] For example, the closure part (210) is made of a thin film-shaped member. The closure part (210) is installed between the upper extension panel (52a) and the lower extension panel (52b) and blocks communication between the exhaust vent part (42) and the expansion development part (40). When the expansion development part (40) expands, the closure part (210) breaks under the influence of a shape change caused by the expansion development part (40), an increase in film surface tension, or an increase in internal pressure. By breaking the closure part (210), the exhaust vent part (42) and the expansion development part (40) communicate. Therefore, even with the fifth embodiment, gas leakage from the exhaust port (46) during the initial expansion development is suppressed, and it is possible to further increase the initial waist restraint performance.

[0060] FIGS. 13 and 14 illustrate an airbag cushion (32) of a passenger protection device (30) according to the sixth embodiment. Also, the exhaust vent (42) is omitted from the illustration. Here, the bubble panel (50) constituting the expansion / deployment section (40) has, in addition to the upper bubble panel (50a) and the lower bubble panel (50b), side panels (300a, 300b) facing each other. The side panels (300a, 300b) face each other in a direction orthogonal to the vertical direction and are respectively joined to the upper bubble panel (50a) and the lower bubble panel (50b).

[0061] For example, the side panels (300a, 300b) are formed in a paired shape (symmetrical shape) and each has a seam line (310a, 310b) along the periphery and is sewn to the upper bubble panel (50a) and the lower bubble panel (50b). The side panels (300a, 300b) are not associated (are not joined) with the bubble panel extension (52) that constitutes the exhaust vent portion (42). The side panels (300a, 300b) define the height (cross-sectional shape at deployment) when the airbag cushion (32) is deployed.

[0062] The same function as in the above embodiment can also be achieved by the occupant protection device (30) according to the 6th embodiment. In particular, according to the airbag cushion (32) formed with a 3D (three-dimensional) shape like the 6th embodiment, it is possible to increase the upward expansion (stroke or thickness) while reducing the overall volume when inflated compared to the airbag cushion formed with a 2D shape like the above embodiment.

[0063] FIG. 15 shows an airbag cushion (32) of a occupant protection device (30) according to the seventh embodiment. Here, the exhaust port (46) is formed on at least one side of the upper extension panel (52a) and the lower extension panel (52b). Accordingly, the tip portion (42b) of the exhaust vent portion (42) is sealed and closed by a seam (54). The exhaust port (46) is, for example, a vent hole formed in the upper extension panel (52a) and is normally open. In addition, if the exhaust port (46) is also formed in the lower extension panel (52b), it may be formed at a position offset from the exhaust port (46) of the upper extension panel (52a). The occupant protection device (30) according to the seventh embodiment can also perform the same function as the above embodiment.

[0064] FIG. 16 shows an airbag cushion (32) of a passenger protection device (30) according to the eighth embodiment. In the above-mentioned embodiments (specifically, embodiments according to FIG. 2, 11, 12 and 15), the constricted structure (220) is installed at the end of the bubble panel extension (52), but in this embodiment, the constricted structure (220) is installed in the middle of the bubble panel extension (52). Specifically, the constricted structure (220) has a constricted portion that is thinner than both of the bottom portion (42a) and the front portion (42b) of the exhaust vent portion (42). Additionally, there may be multiple constricted portions between the bottom portion (42a) and the front portion (42b).

[0065] Each embodiment described above is intended to facilitate understanding of the present invention and is not intended to limit the interpretation of the present invention. Each element, arrangement, material, condition, shape, and size provided by the embodiment is not limited to the examples provided and can be appropriately modified, and the configurations of each embodiment can be combined with one another.

[0066] In addition, it is possible to add additional configurations to the above-described embodiment. For example, a treatment may be applied to increase the membrane surface tension when the airbag cushion (32) is inflated and deployed. Additionally, a treatment may be applied to increase the adhesion of the surrounding area (53) of the exhaust port (46) when the airbag cushion (32) is inflated and deployed. As an example, a surface treatment may be applied to make the inner surface of the bubble panel (50) and / or the bubble panel extension (52) a friction surface. Explanation of the symbols

[0067] 1...Seat back, 2...Seat cushion, 3...Headrest, 4...Reclining mechanism, 10...Seat frame, 20...Seating frame, 22...Side frame, 24...Seat pan, 26...Seat surface, 30...Occupant protection device, 32, 32', 32''...Airbag cushion, 32a...Peripheral section, 34...Inflator, 34a...Stud bolt, 40...Inflation deployment section, 42...Exhaust vent section, 42a...Bottom section, 42b...Front section, 44...Culvert section, 46...Exhaust port, 50...Bubble panel, 50a...Upper bubble panel, 50b...Lower bubble panel, 50c...Peripheral section, 52...Bubble panel extension section, 52a...Upper extension panel, 52b...Lower extension panel, 52c...main edge, 53...periphery, 54...seam, 60...anterior mounting point, 62a, 62b...rear mounting point, 64...rear joint, 70...fixture, 80, 90, 94, 96...arrow, 100...vehicle seat, 105...wrap belt, 107...occupant, 110...occupant's ilium, 200...temporary suture, 210...closure, 220...constriction structure, 300a, 300b...side panel, 310a, 310b...seam line, F...load, Y1...curve, Y2...curve

Claims

Claim 1 A occupant protection device installed inside or below the seat cushion of a vehicle seat, wherein the occupant protection device comprises: an airbag cushion capable of inflating and deploying to push up the seat surface of the seat cushion; and an inflator that supplies gas for inflating and deploying inside the airbag cushion in the event of a vehicle emergency; wherein the airbag cushion has an inflating and deploying section that inflates and deploys by gas from the inflator; and an exhaust vent section installed to protrude from the periphery of the airbag cushion; wherein the inflated and deployed airbag cushion is configured such that the exhaust vent section opens when a load is applied to the inflating and deploying section, thereby communicating the interior of the inflating and deploying section with the exterior; and wherein the airbag cushion has a bubble panel constituting the inflating and deploying section; and a bubble panel extension section installed continuously from the bubble panel and constituting the exhaust vent section; wherein the bubble panel extension section comprises an upper extension panel and a lower extension panel facing each other in the vertical direction; A passenger protection device characterized by having an exhaust port configured between the upper extension panel and the lower extension panel or formed on at least one side of the upper extension panel and the lower extension panel; wherein, when the airbag cushion is inflated and deployed, the bubble panel extension part closes the exhaust port by the upper extension panel and the lower extension panel being in close contact with each other until the load is applied to the inflated deployment part, and the close contact between the upper extension panel and the lower extension panel is released so that the exhaust port is opened when the load is applied to the inflated deployment part, and the bubble panel has an upper bubble panel and a lower bubble panel facing each other in the vertical direction, the upper extension panel is installed continuously from the upper bubble panel, and the lower extension panel is installed continuously from the lower bubble panel. Claim 2 A occupant protection device according to claim 1, characterized in that the load includes the reaction force when the airbag cushion, which has been inflated and deployed, pushes up the seat surface when the occupant is seated on the vehicle seat. Claim 3 A passenger protection device according to claim 1 or 2, characterized in that the bubble panels face each other in a direction orthogonal to the vertical direction, and further have a side panel joined to the upper bubble panel and the lower bubble panel. Claim 4 A passenger protection device according to claim 1 or 2, characterized in that the bubble panel extension is formed more widely at the leading edge of the bubble panel extension than near the boundary with the bubble panel. Claim 5 A passenger protection device according to claim 1 or 2, wherein the airbag cushion has a constricted structure in the middle of the bubble panel extension. Claim 6 A passenger protection device according to claim 1 or 2, wherein the exhaust vent portion has an exhaust port and a surrounding portion of the exhaust port, and the inflated airbag cushion closes the exhaust port by the surrounding portions being in close contact with each other until the load is applied to the inflated portion, and the exhaust port is opened by releasing the close contact of the surrounding portions when the load is applied to the inflated portion. Claim 7 A passenger protection device according to claim 1 or 2, characterized in that the expansion expansion portion is folded in a state prior to expansion expansion, and the exhaust vent portion is folded so as to overlap with the upper part of the folded expansion expansion portion. Claim 8 A passenger protection device according to claim 1 or 2, characterized in that the expansion expansion portion is folded in a state prior to expansion expansion, and the exhaust vent portion is tucked in within the folded expansion expansion portion. Claim 9 A passenger protection device according to claim 1 or 2, wherein the expansion expansion portion is folded in a state prior to expansion expansion, and the exhaust vent portion is sandwiched between the folded layers of the folded expansion expansion portion. Claim 10 A passenger protection device according to claim 1 or 2, wherein the exhaust vent portion is temporarily joined to close at least a portion of the exhaust port, and the temporary joining is resolved by the expansion expansion portion expanding. Claim 11 A passenger protection device according to claim 1 or 2, characterized in that the exhaust vent portion is formed such that the bottom portion on the peripheral side of the airbag cushion is narrower than the front portion of the exhaust vent portion. Claim 12 A passenger protection device according to claim 1 or 2, characterized in that the exhaust vent portion is located on the front side in the front-rear direction of the vehicle seat. Claim 13 delete Claim 14 delete Claim 15 delete

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