Occupant protection devices

Abstract

An occupant protection device is disclosed that can suppress the occurrence of downward slippage and ensure initial lumbar restraint performance. The occupant protection device (30) includes: an airbag cushion (32) disposed inside or below the seat cushion (2) of a vehicle seat (100) and capable of expanding by pushing up the seat surface (26) of the seat cushion (2); and an inflator (34) that supplies gas for expansion into the airbag cushion (32) in the event of a vehicle emergency. The airbag cushion (32) includes: an expansion section (40) that expands using gas from the inflator (34); and an exhaust vent (42) that protrudes from the peripheral edge (32a) of the airbag cushion (32). When expanded, the airbag cushion (32) is configured such that, when a load is applied to the expansion section (40), the exhaust vent (42) opens, connecting the interior of the expansion section (40) to the exterior.

Description

Technical Field

[0001] This invention relates to an occupant protection device disposed inside or under the seat cushion of a vehicle seat. Background Technology

[0002] Typically, for occupants seated in a vehicle, the shoulder strap of the seatbelt crosses diagonally across the occupant's chest, while the lap belt crosses across their waist. In the event of a collision, the seatbelt restrains the occupant's movement. However, especially in a frontal collision, there is a possibility of the occupant's body slipping under the lap belt. Submarine movement is undesirable because the lap belt compresses the passenger's abdomen.

[0003] As a countermeasure against downward sliding, occupant protection devices that incorporate airbags within the seat cushion of a vehicle are known. For example, in Patent Document 1, in the event of a frontal collision, the airbag within the vehicle seat inflates instantaneously, pushing up the front end of the seat cushion, thereby restraining the occupant's waist and suppressing forward movement. Furthermore, in Patent Document 2, vent holes are formed on the airbag.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-118820

[0007] Patent Document 2: Japanese Patent Application Publication No. 2006-327577 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, in Patent Document 1, while restraining the occupant's waist, the airbag maintains a high-pressure state, and the upward thrust of the airbag on the occupant's thighs continues. Therefore, depending on the occupant's seating posture, the airbag may lift and rotate the occupant's waist backward. This phenomenon is particularly likely to occur when the occupant's center of gravity is relatively rearward, such as in a reclined (comfort) position where the vehicle seat is pushed back. If this happens, the seatbelt's lap belt disengages from the occupant's iliac crest, causing downward slippage.

[0010] On the other hand, in Patent Document 2, since the gas inside the airbag escapes through the vent, the aforementioned events or the occurrence of downward sliding can be suppressed. However, there is a problem of initial reduction in lumbar restraint performance, such as the gas inside the airbag escaping before sufficient restraint of the occupant's waist is achieved.

[0011] The purpose of this invention is to provide an occupant protection device that can suppress the occurrence of downward slippage and ensure initial lumbar restraint performance.

[0012] Problem Solving Methods

[0013] One aspect of the present invention relates to an occupant protection device disposed inside or beneath the seat cushion of a vehicle seat. It comprises: an airbag cushion capable of inflating by pushing against the seat surface; and an inflator supplying inflatable gas to the airbag cushion during an emergency. The airbag cushion includes: an inflatable portion that expands using gas from the inflator; and an exhaust vent protruding from the periphery of the airbag cushion. When inflated, the airbag cushion is configured such that, under load, the exhaust vent opens, connecting the interior of the inflatable portion to the exterior.

[0014] According to this method, for example, when an occupant is seated in a vehicle seat, the operation is as follows: In a vehicle emergency, the expansion section receiving gas from the inflator expands and pushes up the seat surface. During the initial stage of this expansion, the internal pressure of the expansion section is maintained because the exhaust vent is not open. Therefore, initial lumbar restraint performance can be ensured. After restraint, a load (e.g., a reaction force caused by the upward push) acts on the expansion section. When the load is applied, the internal pressure of the expansion section is higher than during the initial stage of expansion, and the exhaust vent, which was closed during the initial stage of expansion, opens, causing the internal pressure of the expansion section to decrease. Therefore, further upward pushing on the occupant's waist can be suppressed, preventing downward slippage. Furthermore, gentle restraint can be achieved using the stroke of the expansion section (contraction accompanying the decrease in internal pressure).

[0015] In some embodiments of the present invention, the airbag cushion may also include: a base fabric panel that constitutes the expansion and deployment portion; and a base fabric panel extension portion that is continuously disposed from the base fabric panel and constitutes an exhaust vent portion. Alternatively, the base fabric panel extension portion may also include: an upper extension panel and a lower extension panel that are opposed to each other in the vertical direction; and an exhaust vent that is formed between the upper and lower extension panels, or formed on at least one of the upper and lower extension panels. Furthermore, when the airbag cushion expands and deploys, the base fabric panel extension portion may be configured such that, before the load is applied to the expansion and deployment portion, the upper and lower extension panels are pressed together to close the exhaust vent, while on the other hand, when the load is applied to the expansion and deployment portion, the pressing of the upper and lower extension panels is released and the exhaust vent is opened.

[0016] From another perspective, in another aspect of the present invention, the exhaust vent has an exhaust port and a peripheral portion of the exhaust port. The inflatable airbag can be configured such that, before the load is applied to the inflatable portion, the peripheral portions are pressed together to block the exhaust port, while on the other hand, the load is applied to the inflatable portion to release the pressing of the peripheral portions and open the exhaust port.

[0017] Typically, in an inflatable airbag, the membrane surface tension increases as the internal pressure rises. According to the above method, during the airbag's inflating and deploying, before the load is applied, it is in a phase from the initial stage of expansion to the subsequent normal deployment (and possibly the end of expansion). During this phase, the internal pressure, in relation to the membrane surface tension, maintains the exhaust vents (the upper and lower extended panels or their surrounding areas) in a close or near-closed state. This closes the exhaust vents, ensuring initial waist restraint performance. On the other hand, by applying a load, the internal pressure of the inflatable section becomes higher than in the aforementioned phase. Furthermore, near the exhaust vents, the membrane surface tension increases less compared to other parts (the loaded areas) (i.e., the increase in internal pressure is relatively greater than the increase in membrane surface tension). Thus, the relative balance between internal pressure and membrane surface tension is reversed, the aforementioned close or near-closed state is eliminated, and the exhaust vents open. In this way, the internal pressure of the expansion section is reduced, thus suppressing further upward pressure on the occupant's waist. Attached Figure Description

[0018] Figure 1A This is a perspective view showing the external shape of a vehicle seat equipped with the occupant protection device according to the embodiment.

[0019] Figure 1B It is shown Figure 1A A three-dimensional diagram of the internal frame structure of a vehicle seat.

[0020] Figure 2 This is a top view showing the airbag cushion of the occupant protection device involved in the previous embodiment, which is installed on the seat floor of the vehicle seat.

[0021] Figure 3 This is a cross-sectional view of the occupant protection device involved in the embodiment that is installed after being mounted on the seat base of the vehicle seat.

[0022] Figure 3A This is a cross-sectional view of the occupant protection device according to a variation of the embodiment, showing the state in which the exhaust vent is sandwiched between the folded layers of the expanded portion after folding.

[0023] Figure 4AThis is a schematic cross-sectional view showing the state of the inflated airbag cushion of the occupant protection device according to the embodiment before the load is applied to the inflated part.

[0024] Figure 4B This is a schematic cross-sectional view showing the state of the inflated airbag cushion of the occupant protection device according to the embodiment when a load is applied to the inflated portion.

[0025] Figure 5 It is a graph showing the change in internal pressure of the airbag cushion of the occupant protection device according to the embodiment and the occupant protection device according to the comparative example.

[0026] Figure 6 The diagrams show the relationship between the occupant protection device and the occupant in the comparative example (without exhaust vents). (a) shows the normal state, (b) shows the initial stage (when restrained) of the vehicle in an emergency, and (c) shows the middle or late stage (after restraint) of the vehicle in an emergency.

[0027] Figure 7 The diagram illustrates the relationship between the occupant protection device and the occupant in another comparative example (with a round vent), (a) showing the normal state, (b) showing the initial stage (when restrained) of a vehicle emergency, and (c) showing the middle or later stage (after restraint) of a vehicle emergency.

[0028] Figure 8 The diagram illustrates the relationship between the occupant protection device and the occupant in the embodiment, with (a) showing the normal state, (b) showing the initial stage (when restrained) of a vehicle emergency, and (c) showing the middle or later stage (after restraint) of a vehicle emergency.

[0029] Figure 9 This is a cross-sectional view of the occupant protection device involved in Embodiment 2.

[0030] Figure 10 This is a cross-sectional view of the occupant protection device involved in Embodiment 3.

[0031] Figure 11 This is a top view showing the airbag cushion of the occupant protection device according to Embodiment 4.

[0032] Figure 12 This is a top view showing the airbag cushion of the occupant protection device according to Embodiment 5.

[0033] Figure 13 This is a perspective view showing the state of the airbag cushion of the occupant protection device according to Embodiment Six after it has expanded and deployed.

[0034] Figure 14 It is shown Figure 13Top view of the side panel of the airbag cushion, (A) shows one side panel and (B) shows the other side panel.

[0035] Figure 15 This is a top view showing the airbag cushion of the occupant protection device according to Embodiment Seven.

[0036] Figure 16 This is a top view showing the airbag cushion of the occupant protection device according to Embodiment 8. Detailed Implementation

[0037] Referring to the accompanying drawings, the occupant protection device according to a preferred embodiment of the present invention will be described. In this specification, the terms up / down, left / right, and front / back are defined as follows: When an occupant is seated in a proper posture in a vehicle seat, the direction the occupant is facing is called forward, and the opposite direction is called rearward; when representing coordinate axes, these are called front / back directions. Furthermore, when an occupant is seated in a proper posture in a vehicle seat, the occupant's right side is called the right direction, and the occupant's left side is called the left direction; when representing coordinate axes, these are called left / right directions. Similarly, when an occupant is seated in a proper posture, the direction of the occupant's head is called upward, and the direction of the occupant's waist is called downward; when representing coordinate axes, these are called up / down directions.

[0038] like Figure 1A and Figure 1B As shown, the vehicle seat 100 has: a seat back 1 that supports the back of the occupant; a seat cushion 2 for the occupant to sit on; 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 front passenger seat, but may also be a rear seat.

[0039] A seat frame 10 and a seat cushion 20, forming the seat skeleton, are respectively provided inside the seat back 1 and seat cushion 2. The seat frame 10 and seat cushion 20 are made of metal parts or hard resin and are connected to each other via a tilting mechanism 4. The seat cushion 20 has a pair of side frames 22, 22 arranged separately on the left and right sides, and a seat base plate 24 (see reference) is supported between the pair of side frames 22, 22. Figure 3 The seat cushion 2 may include, for example, a seat cushion made of polyurethane foam or the like covering the surface and surrounding area of ​​the seating frame 20; and a seat cover made of leather or fabric or the like covering the surface of the seat cushion. The upper surface of the seat cover forms the surface on which the occupant sits, i.e., the seat surface 26 of the seat cushion 2.

[0040] The occupant protection device 30 is disposed inside or below the seat cushion 2. For example, the occupant protection device 30 is disposed inside the seat cushion 2 and covered by the seat cover. In this case, the occupant protection device 30 may also be disposed on top of the seat base 24. Alternatively, if the seat base 24 is not provided, it may be disposed on the seat frame 20. In other examples, the occupant protection device 30 is not disposed inside the seat cushion 2, but is disposed below the seat cushion 2. In this case, for example, the occupant protection device 30 is mounted on a bracket fixed to the vehicle seat 100 below the seat cushion 2. The example of the occupant protection device 30 being disposed on top of the seat base 24 will be described below.

[0041] like Figure 2 and Figure 3 As shown, the occupant protection device 30 includes: an airbag cushion 32, which is inflatable and deployable; and an inflator 34, which supplies inflatable gas into the airbag cushion 32 during a vehicle emergency. A vehicle emergency refers to, for example, a frontal collision. Furthermore, in Figure 2 The air inflator 34 is omitted.

[0042] The inflator 34 is electrically connected to the vehicle-side ECU. For example, the inflator 34 receives the impact signal detected by the vehicle-side ECU when a frontal collision occurs and operates to instantaneously supply gas to the airbag cushion 32. Various inflators, such as a gas generating agent, compressed gas, or an inflator filled with both, can be used as the inflator 34. For example, the inflator 34 has an ignition device at the open end of a bottomed cylindrical body. Then, by igniting the gas generating agent inside the cylinder using this ignition device, gas is generated and supplied to the airbag cushion 32 for expansion and deployment through multiple nozzles on the circumferential surface of the cylinder.

[0043] The airbag cushion 32 has: an expansion and deployment portion 40, which expands and deploys by gas from the inflator 34; and an exhaust vent portion 42, which is provided protruding from the peripheral edge 32a of the airbag cushion 32.

[0044] The inflatable portion 40 constitutes most of the airbag cushion 32. The inflatable portion 40 has a capacity of approximately 4 to 6 liters when inflated. An exhaust vent portion 42 protrudes from one end of the inflatable portion 40 and is connected to it. Here, the exhaust vent portion 42 is located on the front side of the vehicle seat 100 in the fore-and-aft direction, protruding forward from the center of the front end of the inflatable portion 40. However, in other embodiments, the exhaust vent portion 42 may be located on the rear side of the vehicle seat 100 in the fore-and-aft direction, or protrude from other positions on the inflatable portion 40.

[0045] The interiors of the expansion section 40 and the exhaust vent section 42 are interconnected. The interior of the expansion section 40 is a closed space, except for the communication 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 side of the exhaust vent section 42 opposite to the communication portion 44. The exhaust port 46 is normally open. As described later, the exhaust port 46 is configured to initially close during a vehicle emergency, and then open.

[0046] The exhaust vent portion 42 is configured such that the root portion 42a on the peripheral edge 32a side of the airbag cushion 32 is narrower than the front portion 42b of the exhaust vent portion 42. Correspondingly, inside the exhaust vent portion 42, the length of the root portion 42a in the left-right direction is shorter than the length of the front portion 42b. Here, the exhaust vent portion 42 is configured to gradually narrow from the front portion 42b to the root portion 42a, and correspondingly, the interior of the exhaust vent portion 42 also gradually narrows from the front portion 42b to the root portion 42a. The connecting portion 44 is located at the root portion 42a, and the exhaust port 46 is located at the front portion 42b.

[0047] The airbag cushion 32 includes: a base fabric panel 50, which constitutes the expansion and deployment portion 40; and a base fabric panel extension 52, which constitutes the exhaust vent portion 42. The base fabric panel extension 52 is continuously provided from the base fabric panel 50. In the base fabric panel extension 52, the front end portion is formed to be wider than near the boundary with the base fabric panel 50. As described above, this is related to the configuration in the exhaust vent portion 42 where the root portion 42a is narrower than the front end portion 42b.

[0048] From another perspective, the airbag cushion 32 can also be viewed as having a necking structure 220 midway through the base fabric panel extension 52. "Midway through the base fabric panel extension 52" refers to the middle or end portion of the base fabric panel extension 52. In the necking structure, for example... Figure 2 As shown, a portion of the airbag cushion 32 in its extended planar state becomes narrower than the other portions (neck). Here, a necking structure 220 is provided such that the neck is formed at the root 42a of the exhaust vent portion 42, that is, at the end of the base fabric panel extension portion 52.

[0049] The base fabric panel 50 has an upper base fabric panel 50a and a lower base fabric panel 50b facing each other in the vertical direction. Similarly, the base fabric panel extension 52 has an upper extension panel 52a and a lower extension panel 52b facing each other in the vertical direction. Moreover, the upper extension panel 52a is continuously provided from the upper base fabric panel 50a, and the lower extension panel 52b is continuously provided from the lower base fabric panel 50b. In addition, an exhaust port 46 is formed between the upper extension panel 52a and the lower extension panel 52b. In other words, the exhaust vent portion 42 forms the peripheral portion 53 of the exhaust port 46 through the upper extension panel 52a and the lower extension panel 52b.

[0050] The upper base fabric panel 50a and the lower base fabric panel 50b can be panels that have been divided into two pieces (each a separate panel), or they can be panels formed by folding a single panel back and overlapping it. The upper extended panel 52a and the lower extended panel 52b are the same.

[0051] The following describes an example of folding a panel. First, a panel made of non-woven fabric or the like is folded back at its center along its length, so that the folded portions overlap each other vertically. Then, the upper base fabric panel 50a and upper extended panel 52a, which form the upper portion of this overlap, and the lower base fabric panel 50b and lower extended panel 52b, which form the lower portion, are sewn together at the seam 54, with their respective peripheral edges 50c and 52c sewn on. However, the vent 46 is not sewn. This sewing creates an air chamber inside the upper base fabric (upper base fabric panel 50a and upper extended panel 52a) and the lower base fabric (lower base fabric panel 50b and lower extended panel 52b) on the inside of the seam 54. By supplying gas from the inflator 34 into this air chamber, the expansion portion 40 expands into a bag shape.

[0052] The airbag cushion 32 has, for example, a front mounting point 60 and rear mounting points 62a and 62b, which serve as mounting points for the vehicle seat 100 to the seat base 24. The front mounting point 60 can also function as a mounting point for mounting the inflator 34 on the side of the vehicle seat 100. For example, when using the aforementioned bottomed cylindrical body as the inflator 34, the axial direction of the cylindrical body is aligned with the left-right direction, and it is housed inside the expansion portion 40. Then, a pair of studs 34a protruding from the outer periphery of the cylindrical body are protruded outwards from the airbag cushion 32 (below the lower base fabric panel 50b) and fastened to the seat base 24 by nuts. Thus, the inflator 34 and the airbag cushion 32 are fastened together to the seat base 24 by bolts 34a and nuts. This jointly fastened portion constitutes the front mounting point 60.

[0053] Rear mounting points 62a and 62b are located behind the front mounting point 60 in the fore-aft direction of the vehicle seat 100. The rear mounting points 62a and 62b are located at the rear corner of the peripheral edge 32a of the airbag cushion 32, and are separated from each other in the left-right direction. The rear mounting points 62a and 62b are, for example, holes in the fastener 70. The rear mounting points 62a and 62b are formed on the peripheral edge 50c of the upper base fabric panel 50a and the lower base fabric panel 50b, located outside the seam 54. Therefore, the rear mounting points 62a and 62b are not located on the inflated portion 40, but rather on the non-inflated portion of the airbag cushion 32.

[0054] The airbag cushion 32, mounted on the seat base 24, is at least partially folded before inflating. For example, the inflatable portion 40 is folded between the front mounting point 60 and the rear mounting points 62a, 62b. As an example, the inflatable portion 40 has multiple overlapping folds 64 on its front side, formed by folding into an accordion shape. In other embodiments, the inflatable portion 40 may be folded in a manner other than an accordion shape (e.g., rolled up), or multiple folds may be combined. The exhaust vent portion 42 may be positioned vertically on the front side of the folds 64, or it may be folded.

[0055] Or, like Figure 3A In the modified example shown, the exhaust vent 42 can also be sandwiched between the folded layers of the expanded portion 40 after folding. For example, the exhaust vent 42 can also be folded rearward from the root portion 42a, with the front end portion 42b sandwiched between the multiple folded portions 64 of the expanded portion 40. Furthermore, regarding other configurations of the exhaust vent 42, using... Figure 9 and 10 As will be described later. With the airbag cushion 32 installed, the inner surfaces of the upper extension panel 52a and the lower extension panel 52b are in contact with each other.

[0056] Alternatively, in other embodiments, the front mounting point 60 may be the same as the rear mounting points 62a and 62b, serving as a hole for fasteners. Alternatively, the position for mounting the inflator 34 may be located on the rear side of the airbag cushion 32, away from the exhaust port 46. This prevents leakage of gas from the inflator 34 from the exhaust port 46 during the initial phase of inflator 34 operation.

[0057] Next, refer to Figure 4A and Figure 4B The state progression of the inflated airbag 32 is explained. Figure 4A This shows the state of the expanded and deployed section 40 before the load is applied after expansion and deployment. Figure 4B This shows the state of the expanded and deployed section 40 under load after expansion and deployment.

[0058] like Figure 4A As shown, when the airbag cushion 32 receives gas from the inflator 34, the expansion portion 40 expands upwards while unfolding to untangle the fold line of the folded portion 64. Within the expanded airbag cushion 32, as indicated by arrow 80, the expansion portion 40 is stretched by internal pressure, generating membrane surface tension and rising. This closes the exhaust port 46. Specifically, the relative relationship between the internal pressure of the airbag cushion 32 and the rising membrane surface tension causes the upper extension panel 52a and the lower extension panel 52b (the peripheral portion 53 of the exhaust port 46) to adhere to each other, thereby closing the exhaust port 46. Therefore, gas within the expansion portion 40 will not leak from the exhaust port portion 42.

[0059] like Figure 4B As shown, when a load F is applied to the expansion section 40, the expansion section 40 deforms. For example, when the load F acts from the outside of the expansion section 40 to the inside, the internal pressure of the expansion section 40 is higher than at the initial stage of expansion. On the other hand, the surface tension of the membrane near the exhaust vent 42 does not increase much. As a result, the exhaust vent 42, which was in a closed state at the initial stage of expansion, opens. That is, the closeness between the upper extended panel 52a and the lower extended panel 52b (the peripheral portion 53 of the exhaust vent 46) is released, and the exhaust vent 46 is opened. As a result, the inside of the expansion section 40 is connected to the outside, and the gas inside the expansion section 40 leaks from the exhaust vent 42.

[0060] The opening principle of the exhaust vent 42 will be explained in more detail below. Typically, in a uniformly inflated airbag, the membrane surface tension increases as the internal pressure rises. This membrane surface tension varies depending on the radius of curvature and the deformation of the airbag itself (for example, the direction of the membrane surface tension changes up, down, left, and right before and after constraint due to the deformation of the airbag). The exhaust vent 42 is located far from the position where the load F acts, where the deformation caused by the load F on the airbag itself is small, and the radius of curvature does not change significantly. Therefore, it can be assumed that even if the load F acts, the membrane surface tension in the exhaust vent 42 will not be greater than in other parts (where the load F acts). On the other hand, in the expansion section 44, the internal pressure rises due to the gas from the inflator 34, the deformation of the airbag caused by the load F, etc.

[0061] Here, the internal pressure from the initial stage of expansion before the application of load F until the normal expansion process thereafter, in relation to the membrane surface tension, maintains the exhaust vent 42 in a closed or nearly closed state. As a result, the exhaust port 46 of the exhaust vent 42 is blocked. Subsequently, when load F is applied, the internal pressure of the expansion section 44 further increases; on the other hand, near the exhaust vent 42, compared to other parts (the parts to which load F is applied), the membrane surface tension does not rise as much (i.e., relatively speaking, the increase in internal pressure is greater than the increase in membrane surface tension). As a result, due to the balance between the internal pressure and membrane surface tension during expansion, the exhaust port 46 of the exhaust vent 42, which has been closed in a closed state since the initial stage of expansion, opens. That is, through the application of load F, the relative balance between internal pressure and membrane surface tension is reversed near the exhaust vent 42, the aforementioned closed or nearly closed state is released, and the exhaust port 46 opens.

[0062] Here, the load F may include, for example, the reaction force of the airbag cushion 32 pushing against the seat surface 26 when the occupant sits on the vehicle seat 100. The inflated portion 40 pushes against the seat surface 26, thereby lifting the occupant's thighs (e.g., near the occupant's buttocks). When the inflated portion 40 pushes against the occupant's thighs via the seat surface 26, a force based on the weight of the seat cushion 2 and the occupant, and the inertial force of the occupant's forward movement, act on the inflated portion 40 as a reaction force. The force acting at this time may be the load F that opens the exhaust vent 46. On the other hand, when the occupant is not seated on the vehicle seat 100, the load F does not act on the inflated portion 40. Therefore, it can also be understood that the conditions for opening the exhaust vent 42 include the pushing force on the occupant's thighs during occupant movement in an emergency (when the lumbar region is restrained).

[0063] Figure 5 This is a graph showing the change in internal pressure of the airbag cushion over time when an occupant sits in the vehicle seat. Curve Y1 represents the airbag cushion of the comparative example without the exhaust vent 42, and curve Y2 represents the airbag cushion 32 of the embodiment with the exhaust vent 42. Time t1 indicates the moment when the inflated airbag cushion presses against the occupant's thigh (when the lumbar region is restrained). Time t1 is, for example, 15 msec from the start of the airbag cushion's inflating and deploying. Up to time t1, the internal pressure in both the comparative example and the embodiment continues to rise almost identically.

[0064] In the comparative example shown by curve Y1, the internal pressure of the airbag cushion continued to rise even after time t1, eventually reaching a peak. Therefore, the airbag cushion of the comparative example continued to push the occupant's thighs upward with higher internal pressure even after the occupant's lumbar region was restrained.

[0065] In contrast, in the embodiment shown by curve Y2, after time t1, the rise in internal pressure of the airbag cushion 32 is suppressed, and it tends to decrease. This is because the exhaust port 46 is opened at time t1. Therefore, the airbag cushion 32 of the embodiment can provide the same initial lumbar restraint as the airbag cushion of the comparative example, and after lumbar restraint, it can continue to restrain the lumbar region with a lower internal pressure than the airbag cushion of the comparative example.

[0066] Next, further reference Figures 6-8 The operation of the occupant protection device 30 in the vehicle emergency according to the embodiment will be described while comparing it with the occupant protection devices according to the two comparative examples. Figure 6 The airbag cushion 32' involved in the comparative example that does not have an exhaust vent 42 (i.e., shown) Figure 5 (The airbag cushion of curve Y1), Figure 7 The illustration shows an airbag 32 in a comparative example where the expansion section does not have an exhaust vent 42, but instead has a circular vent hole (i.e., a circular exhaust vent is formed in a part of the expansion section). Figure 8 This refers to the airbag cushion 32 involved in the implementation. In the figures, (a) shows the normal state, (b) shows the initial stage of a vehicle emergency (with lumbar restraint), and (c) shows the middle or late stage of a vehicle emergency (after restraint).

[0067] First, in the comparative example that does not have an exhaust vent 42, such as Figure 6 As shown in (b), the inflated airbag cushion 32' pushes against the thighs of the occupant 107 via the seat surface 26, thus restraining the occupant 107's waist. However, while restraining the occupant 107's waist, the airbag cushion 32' remains under high pressure, continuing to push against the occupant 107's thighs. As a result, as indicated by arrow 90, the airbag cushion 32' can lift the occupant 107's waist and rotate it backward. Thus, as... Figure 6 As shown in (c), it is possible that the lap belt 105 of the seat belt may detach from the iliac crest 110 of the occupant 107 and the body of the occupant 107 may slide downwards into the underside of the lap belt 105.

[0068] In another comparative example with circular ventilation holes, such as Figure 7 As shown in (b), the inflated airbag cushion 32” pushes the occupant 107’s thighs up via the seat surface 26, but with Figure 6 Compared to the comparative example, its pushing force is weaker. This is because, in Figure 7 In the comparative example shown, after inflation and deployment began, gas leaked from the circular vents within the airbag cushion 32”, failing to maintain internal pressure. Therefore, the initial restraint on the occupant 107's waist was low, such as... Figure 7 As indicated by arrow 94 in (c), the forward movement of occupant 107 cannot be adequately constrained.

[0069] On the other hand, Figure 8 In the embodiment shown, since the exhaust vent 42 is closed until the waist of the occupant 107 is restrained, the initial restraint of the waist of the occupant 107 is... Figure 6 The comparison examples shown are the same (see reference). Figure 8 (b) Furthermore, after restraining the occupant 107's waist, the occupant's waist is more restrained due to the opening of the exhaust vent 42. Figure 6 The comparative example shown is milder. Therefore, it is possible to suppress the rearward rotation of the occupant's waist caused by the airbag cushion 32. Thus, as Figure 8 As shown in (c), the belt 105 is maintained in a position where it is attached to the iliac crest 110 of the occupant 107. In addition, forward movement of the occupant 107, as indicated by arrow 96, is suppressed. Figure 8 The waist constraint shown in (c) becomes a gentle constraint utilizing the stroke of the expansion section 40 (with contraction accompanied by a decrease in internal pressure).

[0070] As described above, the occupant protection device 30 according to the embodiment includes an airbag cushion 32 and an inflator 34. The airbag cushion 32 has an expansion and deployment portion 40, which expands and deploys by gas from the inflator 34; and an exhaust vent portion 42, which protrudes from the peripheral edge 32a of the airbag cushion 32. Furthermore, the expanded airbag cushion 32 is configured such that when a load F is applied to the expansion and deployment portion 40, the exhaust vent portion 42 opens, allowing communication between the interior and exterior of the expansion and deployment portion 40.

[0071] According to this structure, in a vehicle emergency, the expansion section 40, which receives gas from the inflator 34, expands and pushes up the seat surface of the seat cushion 2. In the initial stage of this expansion, the internal pressure of the expansion section 40 is maintained because the exhaust vent 42 is not open. Therefore, initial lumbar restraint performance can be ensured. Furthermore, due to the lumbar restraint, a load F acts on the expansion section 40. When the load F is applied, the internal pressure of the expansion section 40 is higher than in the initial stage of expansion, and the exhaust vent 42, which was in a closed state in the initial stage of expansion, opens. As a result, the internal pressure of the expansion section 40 decreases. Therefore, further upward movement of the occupant's lumbar region can be suppressed, and downward slippage can be prevented.

[0072] Thus, according to the embodiment, an occupant protection device 30 with an airbag cushion 32 having a self-adaptive exhaust vent 42 can be provided, which can both suppress the occurrence of downward slippage and ensure the initial lumbar restraint performance.

[0073] In particular, the exhaust vent portion 42 is configured such that the root portion 42a is narrower than the front portion 42b. Therefore, in the event of a vehicle emergency, the sealing performance of the exhaust vent portion 42 up to the point where the load F is applied to the expansion portion 40 can be improved.

[0074] In addition, according to Figure 3A In the modified example shown, since the exhaust vent 42 is sandwiched between the folded layers of the folded expansion section 40, leakage of gas from the exhaust port 46 of the exhaust vent 42 can be further suppressed during the initial expansion of the airbag cushion 32. Specifically, during the initial expansion, although the time before the membrane surface tension is tightened is short, a predetermined time is required for gas to leak from the exhaust port 46. However, as described above, by configuring the exhaust vent 42, structurally, the flow of gas toward the exhaust vent 42 can be suppressed during the initial expansion. Therefore, gas leakage during the initial expansion can be suppressed, and the initial waist restraint performance can be further improved.

[0075] Next, other implementation methods will be described. Furthermore, regarding these other implementation methods, the description will focus on their differences from the above-described implementation methods, omitting explanations of structures and functions common to the above-described implementation methods.

[0076] exist Figure 9 In the occupant protection device 30 according to Embodiment 2, the exhaust vent portion 42 of the airbag cushion 32 installed on the seat base 24 before expansion and deployment is folded over the upper part of the folded expansion and deployment portion 40. For example, the exhaust vent portion 42 is folded upward from the root portion 42a, and after facing the front of the plurality of fold-back portions 64 of the expansion and deployment portion 40, it is folded backward on the upper part of the uppermost fold-back portion 64, with the front end portion 42b facing backward in a state of overlapping with the upper part of the uppermost fold-back portion 64.

[0077] exist Figure 10 In the occupant protection device 30 according to Embodiment 3 shown, the exhaust vent 42 in the pre-expanded airbag cushion 32 mounted on the seat base 24 is folded into the folded expansion section 40. For example, the upper extension panel 52a and the lower extension panel 52b of the exhaust vent 42 are folded inward from the root portion 42a and inserted into the interior of the expansion section 40. The inserted upper extension panel 52a and lower extension panel 52b are, for example, located inside one of the plurality of fold-back sections 64.

[0078] According to implementation methods two and three, and Figure 3A The modified example shown is the same. Structurally, in the initial stage of expansion and deployment, the flow of gas to the exhaust vent 42 is suppressed. Therefore, in the initial stage of expansion and deployment of the airbag 32, the leakage of gas from the exhaust port 46 of the exhaust vent 42 can be further suppressed.

[0079] Figure 11The airbag 32 of the occupant protection device 30 according to Embodiment 4 is shown. Here, the exhaust vent 42 is temporarily engaged by blocking at least a portion of the exhaust vent 46, and this temporary engagement is eliminated by the expansion of the expansion portion 40.

[0080] For example, the exhaust vent 42 is temporarily sewn near the root 42a or between the root 42a and the front end 42b using a temporary suture 200. The temporary suture 200 sewn the upper extension panel 52a and the lower extension panel 52b together. The temporary suture 200 can completely or partially seal the exhaust vent 46 under normal conditions. The sewing force of the temporary suture 200 is less than that of the seam 54. Therefore, when the expansion portion 40 expands, the temporary suture 200 is cut due to the shape change or increase in membrane surface tension caused by the expansion portion 40. Therefore, according to Embodiment 4, leakage of gas from the exhaust vent 46 during the initial expansion phase can also be suppressed, further improving the initial waist restraint performance.

[0081] Figure 12 The airbag 32 of the occupant protection device 30 according to Embodiment 5 is shown. Here, the exhaust vent 42 has a sealing portion 210 that closes the exhaust port 46, and the sealing portion 210 is configured to open by expanding and unfolding the expansion portion 40.

[0082] For example, the sealing portion 210 is composed of a thin-film member. The sealing portion 210 is installed on the panels between the upper extended panel 52a and the lower extended panel 52b, cutting off the communication between the exhaust vent portion 42 and the expansion portion 40. When the expansion portion 40 expands, the sealing portion 210 breaks due to the shape change, increased film surface tension, or increased internal pressure caused by the expansion portion 40. Due to the breakage of the sealing portion 210, the exhaust vent portion 42 and the expansion portion 40 become connected. Therefore, according to Embodiment 5, leakage of gas from the vent 46 during the initial stage of expansion can also be suppressed, further improving the initial waist restraint performance.

[0083] Figure 13 and Figure 14 The airbag 32 of the occupant protection device 30 according to Embodiment 6 is shown. The exhaust vent 42 is not shown in the diagram. Here, the base fabric panel 50 constituting the expansion section 40, in addition to the upper base fabric panel 50a and the lower base fabric panel 50b, also has opposing side panels 300a and 300b. The side panels 300a and 300b are opposing each other in a direction orthogonal to the vertical direction and are respectively engaged with the upper base fabric panel 50a and the lower base fabric panel 50b.

[0084] For example, side panels 300a and 300b are paired (symmetrical), with seam lines 310a and 310b along their peripheral edges sewn onto the upper and lower base fabric panels 50a and 50b, respectively. Side panels 300a and 300b are not associated with (not joined to) the base fabric panel extension 52 that constitutes the exhaust vent portion 42. Side panels 300a and 300b define the height (cross-sectional shape) of the airbag cushion 32 when deployed.

[0085] The occupant protection device 30 described in Embodiment 6 can also achieve the same function as the embodiments described above. In particular, the airbag cushion 32, which is composed of a 3D shape as in Embodiment 6, can reduce the overall volume when it expands and deploys, while increasing the upward expansion (stroke or thickness), compared to the airbag cushion composed of a 2D shape as in the embodiments described above.

[0086] Figure 15 The airbag cushion 32 of the occupant protection device 30 according to Embodiment 7 is shown. Here, an exhaust port 46 is formed on at least one of the upper extended panel 52a and the lower extended panel 52b. Therefore, the front end 42b of the exhaust vent portion 42 is sewn and closed by the seam 54. The exhaust port 46 is, for example, a vent formed on the upper extended panel 52a, and is normally open. Alternatively, if the exhaust port 46 is also formed on the lower extended panel 52b, it may be formed at a position offset from the exhaust port 46 on the upper extended panel 52a. The occupant protection device 30 according to Embodiment 7 can also achieve the same function as the embodiments described above.

[0087] Figure 16 The airbag cushion 32 of the occupant protection device 30 according to Embodiment 8 is shown. In the above-described embodiments (specifically, with...) Figure 2 , 11 In embodiments (1, 12, and 15), a necking structure 220 is provided at the end of the base fabric panel extension 52. However, in this embodiment, the necking structure 220 is provided in the middle portion of the base fabric panel extension 52. Specifically, the necking structure 220 has a narrower neck than both of the root 42a and the front end 42b of the exhaust vent portion 42. Alternatively, there may be multiple necks between the root 42a and the front end 42b.

[0088] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit or explain the present invention. The elements, their configurations, materials, conditions, shapes, and dimensions included in each embodiment are not limited to the illustrated elements and can be appropriately modified, and the structures of each embodiment can be combined with each other.

[0089] Additionally, additional structures can be added to the above embodiments. For example, a treatment can be implemented to increase the surface tension of the membrane when the airbag cushion 32 expands and unfolds. Furthermore, a treatment can be implemented to improve the fit of the peripheral portion 53 of the exhaust port 46 when the airbag cushion 32 expands and unfolds. For example, a surface treatment can be implemented to use the inner surface of the base fabric panel 50 and / or the base fabric panel extension 52 as a friction surface, etc.

[0090] Symbol Explanation

[0091] 1… Seat backrest 2… Seat cushion

[0092] 3… headrest 4… tilting mechanism

[0093] 10… Seat frame 20… Seating frame

[0094] 22…Side frame 24…Seat base

[0095] 26…seat surface 30…occupant protection device

[0096] 32, 32', 32”... airbag cushion

[0097] 32a…peripheral edge

[0098] 34…Inflator 34a…Stud

[0099] 40…Expansion and unfolding section 42…Exhaust vent section

[0100] 42a…root 42b…front end

[0101] 44…Connecting part 46…Exhaust port

[0102] 50…base fabric panel 50a…upper base fabric panel

[0103] 50b…lower base fabric panel; 50c…peripheral edge.

[0104] 52…Base fabric panel extension 52a…Upper extension panel

[0105] 52b…lower extended panel 52c…peripheral edge

[0106] 53…surrounding area 54…seam

[0107] 60…front mounting point; 62a, 62b…rear mounting point

[0108] 64…Return section 70…Fasteners

[0109] 80, 90, 94, 96… Arrow 100… Vehicle seat

[0110] 105…Waist belt 107…Crew members

[0111] 110…Iliac crest of the occupant 200…Temporary suture

[0112] 210… Closure section 220… Necked structure

[0113] 300a, 300b… Side panels 310a, 310b… Seams

[0114] F…load Y1…curve

[0115] Y2…curve

Claims

1. An occupant protection device that is an occupant protection device provided inside or below a seat cushion of a vehicle seat, which comprises: an airbag cushion that is inflatable in a manner to push up a seat surface of the seat cushion; an inflator that supplies gas for inflation to the inside of the airbag cushion at the time of emergency of the vehicle, the airbag cushion having: an inflation portion that is inflated by the gas from the inflator; an exhaust vent portion that is provided protruding from a peripheral edge of the airbag cushion, the airbag cushion after inflation being configured such that, by a load acting on the inflation portion, the exhaust vent portion is opened, and the inside of the inflation portion is connected to the outside, the exhaust vent portion being provided in a manner to protrude from the inflation portion, the exhaust vent portion having a communication position that communicates with the inside of the inflation portion, and an exhaust port that is located on the opposite side of the communication position, the exhaust vent portion being configured such that the width of the root of the airbag cushion on the peripheral edge side thereof is narrower than the front end portion of the exhaust vent portion, the exhaust vent portion being configured such that the width gradually narrows from the front end portion to the root, the communication position being located at the root, and the exhaust port being located at the front end portion.

2. The occupant protection device according to claim 1, wherein the load includes a reaction force when the inflated airbag cushion pushes up the seat surface when an occupant is seated on the vehicle seat.

3. The occupant protection device according to claim 1 or 2, wherein the airbag cushion has: a base cloth panel that constitutes the inflation portion; a base cloth panel extension portion that is continuously provided from the base cloth panel and constitutes the exhaust vent portion.

4. The occupant protection device according to claim 3, wherein the base cloth panel extension portion has: an upper extension panel and a lower extension panel that are opposed in the vertical direction, the exhaust port being provided between the upper extension panel and the lower extension panel, or being formed in at least one of the upper extension panel and the lower extension panel, the base cloth panel extension portion being configured such that, before the load acts on the inflation portion at the time of inflation of the airbag cushion, the upper extension panel and the lower extension panel are in contact with each other to close the exhaust port, and on the other hand, by the load acting on the inflation portion, the contact of the upper extension panel and the lower extension panel is released and the exhaust port is opened.

5. The occupant protection device according to claim 4, wherein the base cloth panel has: an upper base cloth panel and a lower base cloth panel that are opposed to each other in the vertical direction, the upper extension panel being continuously provided from the upper base cloth panel, the lower extension panel being continuously provided from the lower base cloth panel.

6. The occupant protection device according to claim 5, wherein the base cloth panel further has side panels that are opposed to each other in a direction orthogonal to the vertical direction, and are joined to the upper base cloth panel and the lower base cloth panel.

7. The occupant protection device according to claim 3, wherein the airbag cushion has a necked structure at the middle of the base cloth panel extension portion.

8. The passenger protecting apparatus according to claim 1, wherein the exhaust vent portion has a peripheral portion of the exhaust port, the air bag cushion which is inflated and deployed is configured to occlude the exhaust port by the peripheral portions abutting against each other before the load is applied to the inflated and deployed portion, and on the other hand, to open the exhaust port by the load being applied to the inflated and deployed portion to release the abutment of the peripheral portions.

9. The passenger protecting apparatus according to claim 1, wherein the inflated and deployed portion is folded in a state before inflation and deployment, the exhaust vent portion is folded in a manner to overlap an upper portion of the inflated and deployed portion which is folded.

10. The passenger protecting apparatus according to claim 1, wherein the inflated and deployed portion is folded in a state before inflation and deployment, the exhaust vent portion is folded into the inflated and deployed portion which is folded.

11. The passenger protecting apparatus according to claim 1, wherein the inflated and deployed portion is folded in a state before inflation and deployment, the exhaust vent portion is sandwiched between folded layers of the inflated and deployed portion which is folded.

12. The passenger protecting apparatus according to claim 8, wherein the exhaust vent portion is temporarily joined in a manner to occlude at least a portion of the exhaust port, the temporary joining is released by inflation and deployment of the inflated and deployed portion.

13. The passenger protecting apparatus according to claim 1, wherein the exhaust vent portion is located on a front side in a front-rear direction of the vehicle seat.

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