Occupant protection device

Abstract

Disclosed is an occupant protection device that contributes to an increase in waist restraint capability for an occupant. An occupant protection device 30 provided inside or below a seat cushion 2 of a vehicle seat 100 includes an airbag cushion 32 that can be inflated so as to push up a seat surface 26 of the seat cushion 2, and at least one inflator 34 (inflator 34a, 34b) that operates in a vehicle emergency. The at least one inflator 34 is configured so as to operate at least once in a vehicle emergency to supply inflation gas to the internal space of the airbag cushion 32, and the supply timing of the inflation gas is controlled, on the basis of sensing from the vehicle, by varying the timing at which the gas is generated from at least one or more gas generation units.

Description

Occupant protection devices

[0001] The present invention relates to an occupant protection device that is provided inside or below a seat cushion of a vehicle seat.

[0002] When a vehicle is involved in a frontal collision, an occupant wearing a seatbelt tends to move forward due to inertia. Patent Document 1 describes an occupant protection device that, in the event of such a frontal collision, instantly inflates an airbag in the vehicle seat to raise the front end of the seat cushion, thereby restricting the forward movement of the occupant's lower back.

[0003] Japanese Patent Application Laid-Open No. 2007-118820

[0004] In Patent Document 1, the airbag is fixed to the seat pan and pushes up the front lower end of the seat cushion when inflated. However, for example, in the later stages of a collision, the internal pressure of the inflated airbag may decrease due to the load from the occupant, which may reduce the restraining force on the occupant's waist.

[0005] An object of the present invention is to provide an occupant protection device that contributes to improving the performance of restraining the lumbar region of an occupant.

[0006] An occupant protection device according to one aspect of the present invention is an occupant protection device that is provided inside or below a seat cushion of a vehicle seat, and includes an airbag cushion that can be inflated to push up the seat surface of the seat cushion, and at least one inflator that is activated in the event of a vehicle emergency, and is configured to be activated at least twice in the event of the vehicle emergency and to supply inflation gas to the internal space of the airbag cushion at least twice.

[0007] According to this aspect, inflation gas is supplied to the airbag cushion at least twice, with a time interval between each supply. The first inflation of the airbag cushion pushes up the seat surface, restraining the occupant's lower back. Even if the internal pressure of the airbag cushion subsequently drops, the second inflation of the airbag cushion increases the internal pressure of the airbag cushion, thereby increasing the force pushing up the seat surface. Therefore, the restraining force on the occupant's lower back can be maintained.

[0008] As a more detailed example, consider a case where a vehicle experiences a frontal collision with an occupant seated in a normal posture on a seat cushion and wearing a seat belt. During this initial inflation, the airbag cushion lifts the area around the occupant's thighs, which is close to the buttocks, thereby restricting forward movement of the occupant's lower back and encouraging clockwise rotation of the occupant's pelvis (backward rotation of the lower back). This restricts movement of the occupant's chest. The airbag cushion then inflates a second time at a later timing (e.g., when the internal pressure of the airbag cushion decreases and the lower back restraining force may decrease). This allows the airbag cushion to again lift the area around the thighs, thereby controlling the behavior of the lower back (restricting forward movement and promoting backward rotation). Therefore, chest movement of the occupant can be restricted throughout the entire collision period, including the later stages of the collision, improving the lumbar restraint performance.

[0009] Another aspect of the present invention provides an occupant protection device that is provided inside or below a seat cushion of a vehicle seat, and includes an airbag cushion that is inflatable so as to push up the seat surface of the seat cushion, and at least one inflator that is activated in the event of a vehicle emergency, wherein the at least one inflator is configured to be activated at least once in the event of a vehicle emergency to supply inflation gas to the internal space of the airbag cushion, and the timing of supplying the inflation gas to the airbag cushion is controlled by varying the timing of gas generation from at least one gas generating unit based on sensing from the vehicle.

[0010] According to this aspect, since the timing of supplying inflation gas is controlled, it is possible to configure the airbag cushion so that inflation gas is supplied at least twice with a time interval between each supply, thereby suppressing movement of the occupant's chest and improving lumbar restraint performance throughout the entire collision period, including the later part of the collision period, as described above.

[0011] 1A is a perspective view showing the external shape of a vehicle seat provided with an occupant protection device according to an embodiment; FIG. 1B is a perspective view showing an internal frame structure of the vehicle seat of FIG. 1A; FIG. 1C is a diagram showing an occupant protection device according to an embodiment in a side cross section of the vehicle seat, where (a) shows the state before inflation of an airbag cushion and (b) shows the state after inflation of the airbag cushion; FIG. 1D is a block diagram showing the control configuration of the occupant protection device according to a first embodiment; FIG. 1E is a flowchart showing a control method of the occupant protection device according to the first embodiment; FIG. 1F is a graph showing the internal pressure of the airbag cushion over time when inflated twice for the first embodiment; FIG. 1G is a graph showing the chest deflection of an occupant over time in a vehicle emergency for the comparative example and the first embodiment; FIG. 1H is a diagram for explaining the effect of the occupant protection device according to an embodiment from another perspective, where (a) shows the comparative example and (b) shows the first embodiment; FIG. 1I is a block diagram showing the control configuration of the occupant protection device according to a second embodiment; and FIG. 1I is a flowchart showing a control method of the occupant protection device according to the second embodiment.

[0012] An occupant protection device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In this specification, up / down, left / right, and front / rear are defined as follows. When an occupant is seated in a seat (vehicle seat) in a normal posture, the direction the occupant faces is referred to as the forward direction, and the opposite direction is referred to as the rearward direction, and the axes of coordinates are referred to as the front / rear direction. Furthermore, when an occupant is seated in a vehicle seat in a normal 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, and the axes of coordinates are referred to as the left / right direction. Similarly, when an occupant is seated in a normal posture, the direction of the occupant's head is referred to as the upward direction, and the direction of the occupant's waist is referred to as the downward direction, and the axes of coordinates are referred to as the up / down direction.

[0013] In addition, in this document, "occupant" refers to a person with a physique equivalent to that of an average American man, conforming to the frontal collision test dummy (Hybrid III AM50 / frontal collision test dummy established by the NHTSA [National Highway Traffic Safety Administration] standard [49CFR Part 572 Subparts E and O]), with approximate dimensions of 175 cm in height, 88 cm in seated height, and 78 kg in weight.

[0014] 1A and 1B, a vehicle seat 100 includes a seat back 1 that supports the back of an 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 is, for example, a driver's seat or a passenger seat, but may also be a rear seat.

[0015] A back frame 10 and a seat frame 20, which form the framework of the seat, are provided inside the seat back 1 and the seat cushion 2, respectively. The back frame 10 and the seat frame 20 are made of processed metal parts or hard resin, and are connected to each other via a reclining mechanism 4. The seat frame 20 has a pair of side frames 22, 22 spaced apart on the left and right, and a seat pan 24 (see FIG. 2) is installed between the front portions of the pair of side frames 22, 22. The seat pan 24 is located below the front portion of the seat cushion 2, and springs 25 that support the seat cushion 2 are provided behind the seat pan 24.

[0016] The seat cushion 2 includes, for example, a seat pad made of urethane foam or the like that covers the surface and periphery of the seat frame 20, and a seat cover made of leather, fabric, or the like that covers the surface of the seat pad. The upper surface of the seat cover forms the surface on which the occupant sits, i.e., the seating surface 26 of the seat cushion 2.

[0017] The occupant protection device 30 is provided inside or below the seat cushion 2. For example, the occupant protection device 30 is provided inside the seat cushion 2 and covered by a seat cover. In this case, the occupant protection device 30 may be provided on the upper surface of the seat pan 24. Alternatively, if a seat pan 24 is not provided, the occupant protection device 30 may be provided on the seating frame 20. In another example, the occupant protection device 30 is provided below the seat cushion 2 rather than inside the seat cushion 2. In this case, for example, the occupant protection device 30 is attached to a bracket fixed to the vehicle seat 100 below the seat cushion 2. An example in which the occupant protection device 30 is provided on the upper surface of the seat pan 24 will be described below.

[0018] 2, the occupant protection device 30 includes an airbag cushion 32 that is inflatable so as to push up the seat surface 26 of the seat cushion 2, and at least one inflator 34 that is activated in the event of a vehicle emergency, such as a frontal collision of the vehicle.

[0019] The airbag cushion 32 is a bag that inflates when supplied with gas from the inflator 34. The airbag cushion 32 is formed into a bag shape by sewing or bonding one or more pieces of base fabric (e.g., nonwoven fabric) at appropriate positions, or by weaving using a one-piece woven (OPW) weave. The airbag cushion 32 is placed on the support surface 24a of the seat pan 24, for example, in a folded state. The folding manner may be arbitrary, for example, an accordion shape, a roll shape, or a combination thereof. The airbag cushion 32 in the folded state deploys when supplied with gas from the inflator 34, and inflates with the support surface 24a of the seat pan 24 as a reaction surface.

[0020] The inflator 34 is electrically connected to the vehicle ECU. For example, the inflator 34 receives a signal from the vehicle ECU detecting an impact during a frontal collision of the vehicle and is activated to instantly supply gas to the airbag cushion 32. The inflator 34 can be either a disk-type or a cylinder-type inflator, and can be filled with a gas generant, compressed gas, or both. Known inflators are generally classified into three types: pyrotechnic inflators, compressed gas inflators, and hybrid inflators. Pyrotechnic inflators rely solely on combustion to provide inflation gas, while compressed gas inflators use minimal explosives to open a chamber to release compressed inflation gas. Hybrid inflators combine combustion with compressed gas storage to fill the cushion with inflation gas. In one example of this embodiment, the cylinder-type inflator 34 has a squib (ignition device) at the open end of a bottomed cylinder. The squib then ignites the gas generating agent inside the cylinder, generating gas, which is then supplied into the airbag cushion 32 through a plurality of nozzles on the circumferential surface of the cylinder.

[0021] The airbag cushion 32 can be attached to the seat pan 24 by various methods. For example, the front and rear portions and / or the middle portion of the airbag cushion 32 can be attached to the seat pan 24 using fasteners such as bolts or rivets. In the example shown in FIG. 2 , the front and rear portions of the airbag cushion 32 are attached. The attachment points of the airbag cushion 32 to the seat pan 24 can also serve as attachment points for attaching the inflator 34 to the seat pan 24. For example, if the inflator 34 is a cylindrical body with a bottom, as described above, the cylindrical body is housed inside the airbag cushion 32 with its axis aligned with the left-right direction. Then, stud bolts 35 protruding from the outer periphery of the cylindrical body protrude outside the airbag cushion 32 and are inserted into the seat pan 24 from the mounting surface 24a side, and are fastened to the seat pan 24 with nuts. In this manner, the inflator 34 and the airbag cushion 32 are fastened together to the mounting surface 24a of the seat pan 24 by the stud bolts 35 and nuts.

[0022] The airbag cushion 32 is positioned so as to push up the area around the thighs near the buttocks of an occupant P who is seated on the seat cushion 2 in a normal posture and wearing a seat belt (not shown in FIG. 2 ). For example, the center 32c of the inflated airbag cushion 32 is located below the thighs of the occupant P near the buttocks. When inflated, the airbag cushion 32 lifts the area around the thighs near the buttocks of the occupant P via the seat surface 26, thereby lifting the entire area from the thighs to the knees of the occupant P. This applies a force that rotates the pelvis of the occupant P in a clockwise direction (retroflex rotation of the lower back). This action prevents the vertebrae of the occupant P from being pushed up, keeping the occupant P's spine in a downward position. In other words, because the spine is not pushed up, no phase difference occurs in the ribs, and no strain is placed on the occupant P's chest, while suppressing forward movement of the occupant P's lower back. It also suppresses the occurrence of the submarine phenomenon.

[0023] The airbag cushion 32 assumes a shape as shown in FIG. 2( b) when inflated and deployed. Specifically, when the airbag cushion 32 is inflated and deployed, the top of the front portion 32a is located higher than the top of the rear portion 32b. The front portion 32a is located forward of the center 32c of the airbag cushion 32, and the top of the front portion 32a may be near the front end of the airbag cushion 32. The rear portion 32b is located rearward of the center 32c of the airbag cushion 32, and the top of the rear portion 32b may be near the rear end of the airbag cushion 32. Comparing the amount of lifting of the occupant P by the front portion 32a and the rear portion 32b, it can be said that the top of the front portion 32a lifts the area from the thighs to the knees of the occupant P higher than the top of the rear portion 32b.

[0024] In this embodiment, at least one inflator 34 is configured to be activated at least twice in the event of a vehicle emergency, supplying inflation gas to the interior space of the airbag cushion 32 at least twice. For ease of explanation, an example in which the activation timing is two times will be described below. Examples of such two (multiple) inflations include a configuration in which two (multiple) inflators 34 are used, and a configuration in which one inflator 34 is used. The former will be described below as a first embodiment, and the latter as a second embodiment.

[0025] [First Embodiment] Fig. 3 shows a control configuration 60 including the inflators 34a, 34b of the occupant protection device 30. The at least one inflator 34 includes a first inflator 34a and a second inflator 34b. The inflators 34a, 34b are each configured to supply inflation gas to the interior space of the airbag cushion 32. The inflators 34a, 34b have the same performance. Having the same performance is desirable from the perspective of quality module management.

[0026] The inflators 34a, 34b can be arranged side by side, front to back or left to right. For example, the inflators 34a, 34b can be arranged at different positions in the longitudinal direction of the vehicle. For example, the front and rear of the airbag cushion 32 may be attached to the seat pan 24 by the inflator 34a at the front and the inflator 34b at the rear. The inflators 34a, 34b can also be arranged along the longitudinal direction of the vehicle. For example, in the case of cylindrical inflators 34a, 34b, the axes of the cylinders can be aligned in the longitudinal direction of the vehicle. In another embodiment, the inflators 34a, 34b can be arranged at different positions in the transverse direction of the vehicle, and in this case, they can be arranged along the transverse direction of the vehicle.

[0027] The controller 70 in the occupant protection device 30 is an electronic control unit (ECU) including a CPU 71, a memory 72, and an input / output interface 73, and is configured as, for example, a microcomputer. The CPU 71 executes desired calculations according to a control program and performs various processes and controls. The memory 72 includes, for example, a ROM and a RAM. The ROM stores the control program and control data processed by the CPU 71, and the RAM is primarily used as a work area for various control processes. An external sensor 75 and the inflators 34a, 34b are electrically connected to the input / output interface 73. The sensor 75 detects a vehicle collision and may be any of various known types, such as an acceleration sensor or a pressure sensor. With this configuration, the controller 70 receives an input signal from the sensor 75 and outputs an activation signal to the inflators 34a, 34b in the event of a vehicle emergency (determines whether the vehicle has experienced a frontal collision and, when it is determined that a frontal collision has occurred).

[0028] The controller 70 may be configured as an airbag ECU capable of communicating with the vehicle-side ECU, and may control the activation of not only the inflators 34a, 34b of the occupant protection device 30, but also inflators in other airbag devices (for example, a front airbag device, a curtain airbag device, etc.). In another embodiment, the vehicle-side ECU may determine whether or not the vehicle has experienced a frontal collision, and the controller 70 may receive collision information from the vehicle-side ECU and output an activation signal to the inflators 34a, 34b.

[0029] 4 is a flowchart showing a control method for the occupant protection device 30. This control method is executed by the controller 70 when a vehicle collision occurs (S10).

[0030] In this control method, the activation timings of the inflators 34a and 34b are made different. That is, the inflator 34a is activated at a first timing t1, and the inflator 34b is activated at a second timing t2 that is different from the first timing. Here, the controller 70 changes the output timing of the activation signal so that the second inflator 34b is activated later than the first inflator 34a. Specifically, first, the controller 70 outputs an activation signal to supply inflation gas from the first inflator 34a to the airbag cushion 32 (S11), and then outputs an activation signal to supply inflation gas from the second inflator 34b to the airbag cushion 32 (S12).

[0031] Here, the difference in activation timing (ignition delay time) between the inflators 34a and 34b is preferably, for example, 15 to 40 msec. If it is less than 15 msec, it will be almost the same as activating the inflators 34a and 34b simultaneously, which may result in an excessive increase in the internal pressure of the airbag cushion 32 at the initial stage of inflation. If it exceeds 40 msec, the internal pressure of the airbag cushion 32 will drop too much. By setting the difference in timing between 15 and 40 msec, the internal pressure of the airbag cushion 32 at the initial stage of inflation can be kept within an appropriate range, and the internal pressure of the airbag cushion 32 can be increased again before it drops too much.

[0032] Within the range of 15 to 40 msec, 25 msec or around 35 msec is preferable, but it should be noted that this delay time is significantly affected by the type and performance of the inflator used.

[0033] FIG. 5 is a graph showing the internal pressure of the airbag cushion 32 over time when the airbag cushion 32 is inflated twice. The internal pressure of the airbag cushion 32 is zero until a vehicle emergency occurs. When the inflator 34a is activated at a first timing t1 during a vehicle emergency, the internal pressure of the airbag cushion 32 increases. This causes the airbag cushion 32 to deploy and perform the first inflation. After reaching an initial peak value P1, the internal pressure of the airbag cushion 32 begins to decrease due to the load from the occupant P. Then, when the inflator 34b is activated at a second timing t2 before the internal pressure of the airbag cushion 32 has fully decreased, the internal pressure of the airbag cushion 32 increases again. This causes the airbag cushion 32 to perform the second inflation. After exceeding the initial peak value P1 and reaching a later peak value P2, the internal pressure of the airbag cushion 32 begins to decrease due to the load from the occupant P. The later peak value P2 is greater than the initial peak value P1, and if the inflators 34a, 34b have the same performance as described above, the later peak value P2 can be approximately twice the initial peak value P1.

[0034] 5, the second timing t2 may be the timing when the internal pressure of the airbag cushion 32 reaches, for example, 50% of the initial peak value P1. In other embodiments, the second timing t2 may be the timing when the internal pressure of the airbag cushion 32 reaches 70%, 60%, 40%, 30%, or 20% of the initial peak value P1.

[0035] The inflation and deployment behavior of the airbag cushion 32 can also be controlled by the location of the inflators 34a, 34b. For example, the inflator 34a, which is initially ignited, is positioned as far forward as possible in the longitudinal direction of the vehicle. For example, the inflator 34a is located toward the front of the vehicle, and the inflator 34b is located toward the rear of the vehicle. This allows the forward portion 32a of the folded airbag cushion 32 to be supplied with inflation gas earlier and in greater volume than the rear portion 32b upon initial ignition (first timing t1). Therefore, the forward portion 32a inflates and deploys earlier and to a greater extent than the rear portion 32b. Then, after the second ignition (second timing t2), the internal pressure of the airbag cushion 32 increases and reaches its maximum, causing the airbag cushion 32 to fully deploy, maximizing the upward force on the seat surface.

[0036] 6 is a graph showing the chest deflection of the occupant P over time in a vehicle emergency for the comparative example and the first embodiment. The occupant P is seated on the seat cushion 2 in a normal posture and wearing a seat belt. In the comparative example, the occupant protection device 30 is not provided. In the comparative example, the chest deflection of the occupant P continues to increase over time in a vehicle emergency.

[0037] In contrast, in the case of the first embodiment, in the event of a vehicle emergency, the first inflator 34a is activated at a first timing t1. This causes the airbag cushion 32 to inflate for the first time, lifting the area around the thighs of the occupant P, which is close to the buttocks. This suppresses forward movement of the occupant P's waist and encourages backward rotation of the occupant P's waist. This suppresses movement of the occupant P's chest. Note in FIG. 6 that chest deflection is reduced between timing t1 and timing t2 compared to the comparative example.

[0038] In the first embodiment, the second inflator 34b is activated at a subsequent timing t2. This causes the airbag cushion 32 to inflate a second time, again lifting the area near the thighs of the occupant P, which again controls the behavior of the occupant P's lower back (reducing forward movement and promoting backward rotation), thereby reducing movement of the occupant P's chest. Note that in Figure 6, the peak chest deflection is reduced after timing t2 compared to the comparative example.

[0039] In this way, according to the first embodiment, movement of the occupant P's chest can be suppressed throughout the entire collision period, including the later part of the collision period (for example, after timing t1), thereby improving the lumbar restraint performance.

[0040] 7A and 7B are diagrams illustrating the effects of the first embodiment from a different perspective, with FIG. 7A showing a comparative example and FIG. 7B showing the first embodiment. The comparative example does not include the occupant protection device 30. In the comparative example, in the event of a vehicle emergency, the sternum of the occupant P follows a linear path in the front-to-rear direction (see arrow 81). In contrast, in the first embodiment, in the event of a vehicle emergency, the sternum of the occupant P follows a circular path (see arrow 82). As a result, chest deflection is suppressed.

[0041] That is, in the first embodiment, when the airbag cushion 32 is deployed to restrain the occupant P's waist, a force acts to push the waist and the entire spine connected to it upward. As a result, the spine behind the occupant P's sternum moves upward while remaining stationary in the fore-and-aft direction of the vehicle. Since this movement occurs during a frontal collision, a force that moves the occupant P relatively forward is applied to the occupant P. However, as a result of the deployment of the airbag cushion 32, a force that moves the occupant P from the waist to the spine is applied upward, as described above, and the occupant P's sternum moves downward and forward of the occupant P. At this time, the occupant P's sternum falls forward and diagonally downward, which limits the reduction in the distance between the occupant P and the seat belt 300 and the front airbag cushion 310 relative to the direction of movement of the tip of the sternum (i.e., increases the gap). As a result, chest deflection due to the force applied to the occupant P from the seat belt 300 and the front airbag cushion 310 can be suppressed.

[0042] 8 and 9, a second embodiment will be described. Here, a single inflator 34 is used. Note that the same reference numerals are used to designate parts common to the first embodiment, and a description thereof will be omitted.

[0043] As shown in FIG. 8 , the inflator 34 has multiple squibs, including a first squib 400a and a second squib 400b, which are each ignited in the event of a vehicle emergency. As described above, either a disk-type or a cylinder-type inflator 34 can be used. For example, the inflator 34 has two (multiple) gas generating units corresponding to the squibs 400a and 400b. The inflator 34 generates gas by igniting a gas generating agent in one of the gas generating units with the squib 400a, and supplies the inflation gas to the airbag cushion 32. The inflator 34 also generates gas by igniting a gas generating agent in the other gas generating unit with the squib 400b, and supplies the inflation gas to the airbag cushion 32.

[0044] The controller 70 in the passenger protection device 30 includes a CPU 71, a memory 72, and an input / output interface 73, and receives an input signal from a sensor 75 and outputs an ignition signal to the squibs 400a, 400b in the event of a vehicle emergency.

[0045] As shown in FIG. 9 , the squibs 400a and 400b are activated at different timings. That is, the squib 400a is activated at a first timing t1, and the squib 400b is activated at a second timing t2. Specifically, first, an ignition signal is output from the first squib 400a to supply inflation gas to the airbag cushion 32 (S21), and then an ignition signal is output from the second squib 400b to supply inflation gas to the airbag cushion 32 (S22). The difference in ignition timing between the squibs 400a and 400b (t2-t1) may be, for example, 15 to 40 msec, similar to the difference in activation timing between the inflators 34a and 34b in the first embodiment.

[0046] Therefore, the second embodiment also functions in the same way as the first embodiment. That is, because the changes in internal pressure, chest deflection, etc. are as shown in Figures 5 to 7, movement of the chest of the occupant P is suppressed throughout the entire collision period, including the later part of the collision period (e.g., after time t1), and the lumbar restraint performance can be improved.

[0047] The occupant protection device 30 according to the embodiment including the first and second examples described above can be understood from another perspective as follows: That is, the occupant protection device 30 according to the embodiment is an occupant protection device 30 provided inside or below the seat cushion 2 of the vehicle seat 100, and includes an airbag cushion 32 that is inflatable so as to push up the sitting surface 26 of the seat cushion 2, and at least one inflator 34 that is activated in the event of a vehicle emergency, the at least one inflator 34 is configured to be activated at least once in the event of the vehicle emergency to supply inflation gas to the internal space of the airbag cushion 32, and the timing of supplying the inflation gas to the airbag cushion 32 is controlled by varying the timing of gas generation from at least one or more gas generators based on sensing from the vehicle (information from a sensor 75).

[0048] This means that the mass flow can be controlled by, for example, the explosive shape of the single inflator 34 or the compartment structure.

[0049] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0050] For example, instead of a configuration in which the airbag cushion 32 directly pushes up the seat surface 26, a push-up member may be interposed between the airbag cushion 32 and the seat surface 26. That is, when the airbag cushion 32 inflates, it may tilt or rotate a push-up member (for example, a plate with an upwardly inclined front end), thereby pushing up the seat surface 26 via the push-up member.

[0051] In addition, in consideration of the severity of the collision and the layout, the inflators 34a, 34b may have different performances. In this case, it is preferable that the output of the inflator 34b is greater than the output of the inflator 34a, but the reverse may be possible depending on the severity of the collision and the layout.

[0052] 5, the internal pressure data from the inflator 34 has two peaks (an initial peak value P1 and a later peak value P2), but is not limited to this. For example, the internal pressure data from the inflator 34 may be a gently rising straight line, or may be a two-step curve without a valley.

[0053] <Additional Considerations Regarding Various Embodiments> [Embodiment 1] An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an airbag cushion that is inflatable so as to push up a sitting surface of the seat cushion; and at least one inflator that is activated in a vehicle emergency, wherein the at least one inflator is configured to be activated at least once in the event of the vehicle emergency to supply inflation gas to an interior space of the airbag cushion, and the timing of supplying the inflation gas to the airbag cushion is controlled by varying the timing of gas generation from at least one gas generator based on sensing from the vehicle. [Embodiment 2] An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an airbag cushion that is inflatable so as to push up a sitting surface of the seat cushion; and at least one inflator that is activated in a vehicle emergency, wherein the at least one inflator is configured to be activated at least twice in the event of the vehicle emergency to supply inflation gas to the interior space of the airbag cushion at least twice.

[0054] [Embodiment 3] An occupant protection device according to embodiment 1 or 2, wherein the at least one inflator includes a first inflator and a second inflator, each capable of supplying inflation gas to the internal space of the airbag cushion, and the first inflator and the second inflator have different activation times in the event of a vehicle emergency.

[0055] [Embodiment 4] The occupant protection device of embodiment 3, wherein the first inflator and the second inflator have the same performance.

[0056] [Embodiment 5] The occupant protection device according to embodiment 3 or 4, wherein the first inflator and the second inflator are provided at different positions in the vehicle longitudinal direction.

[0057] [Embodiment 6] The passenger protection device according to any one of embodiments 3 to 5, wherein the second inflator is activated 15 to 40 msec later than the first inflator.

[0058] [Embodiment 7] An occupant protection device according to any one of embodiments 3 to 6, further comprising a controller connected to the first inflator and the second inflator, wherein the controller, in the event of a vehicle emergency, outputs an activation signal to the first inflator so that the first inflator activates at a first timing, and outputs an activation signal to the second inflator so that the second inflator activates at a second timing different from the first timing.

[0059] [Embodiment 8] The occupant protection device of embodiment 1 or 2, wherein the at least one inflator comprises an inflator having a plurality of squibs including a first squib and a second squib that are each ignited in the event of a vehicle emergency, and the first squib and the second squib have different ignition timings in the event of the vehicle emergency.

[0060] [Embodiment 9] The passenger protection device of embodiment 8, wherein the second squib ignites 15 to 40 msec later than the first squib.

[0061] [Embodiment 10] An occupant protection device according to embodiment 8 or 9, further comprising a controller connected to the inflator, wherein the controller, in the event of a vehicle emergency, outputs an ignition signal to the first squib so that the first squib ignites at a first timing, and outputs an ignition signal to the second squib so that the second squib ignites at a second timing different from the first timing.

[0062] [Embodiment 11] The occupant protection device according to any one of embodiments 1 to 10, wherein the airbag cushion is disposed on a seat pan and configured to inflate and deploy using the seat pan as a reaction surface.

[0063] 12. The occupant protection device of claim 11, wherein the airbag cushion is attached to the seat pan by the at least one inflator.

[0064] [Embodiment 13] An occupant protection device according to any one of embodiments 1 to 12, in which, when an occupant is seated on the seat cushion in a normal posture and wearing a seat belt, the inflation of the airbag cushion encourages the occupant's waist to rotate backward.

[0065] [Embodiment 14] The occupant protection device of embodiment 7, wherein the first timing is before the second timing, and the second timing is a timing after the internal pressure of the airbag cushion reaches an initial peak value due to activation of the first inflator and starts to decrease, but before it reaches its final decrease, and the internal pressure of the airbag cushion reaches a later peak value that exceeds the initial peak value due to activation of the second inflator.

[0066] [Embodiment 15] The occupant protection device according to any one of embodiments 1 to 13, wherein the airbag cushion, when inflated and deployed, has a top of the front portion positioned higher than a top of the rear portion.

[0067] [Embodiment 16] The occupant protection device of embodiment 5, wherein one of the first inflator and the second inflator, which is provided on the front side of the vehicle, is activated first.

[0068] 1...seat back, 2...seat cushion, 3...headrest, 4...reclining mechanism, 10...back frame, 20...seating frame, 22...side frame, 24...seat pan, 24a...support surface, 25...spring, 26...seat surface, 30...occupant protection device, 32...airbag cushion, 32a...front portion, 32b...rear portion, 32c...center, 34, 34a, 34b...inflator, 35...stud bolt, 60...control configuration, 70...controller, 71...CPU, 72...memory, 73...input / output interface, 75...sensor, 81, 82...arrows, t1...first timing, t2...second timing, 300...seat belt, 310...airbag cushion of front airbag, 400a, 400b...squib, P...occupant

Claims

1. An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an airbag cushion that is inflatable so as to push up the seat surface of the seat cushion; and at least one inflator that operates in the event of a vehicle emergency, wherein the at least one inflator is configured to operate at least once in the event of the vehicle emergency to supply inflation gas to the internal space of the airbag cushion, and the timing of the supply of inflation gas to the airbag cushion is controlled by varying the timing of gas generation from at least one gas generator based on sensing from the vehicle.

2. An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an airbag cushion that is inflatable so as to push up the seat surface of the seat cushion; and at least one inflator that operates in the event of a vehicle emergency, wherein the at least one inflator is configured to operate at least two times in the event of the vehicle emergency and to supply inflation gas to the internal space of the airbag cushion at least two times.

3. An occupant protection device as claimed in claim 1 or 2, wherein the at least one inflator includes a first inflator and a second inflator each capable of supplying inflation gas to the internal space of the airbag cushion, and the first inflator and the second inflator have different activation timings in the event of a vehicle emergency.

4. The passenger protection device according to claim 3, wherein the first inflator and the second inflator have the same performance.

5. The passenger protection device according to claim 3, wherein the first inflator and the second inflator are provided at different positions in the vehicle longitudinal direction.

6. An occupant protection device according to claim 3, wherein the second inflator is activated 15 to 40 msec after the first inflator.

7. An occupant protection device as described in claim 3, further comprising a controller connected to the first inflator and the second inflator, wherein, in the event of a vehicle emergency, the controller outputs an activation signal to the first inflator so that the first inflator is activated at a first timing, and outputs an activation signal to the second inflator so that the second inflator is activated at a second timing different from the first timing.

8. An occupant protection device as claimed in claim 1 or 2, wherein the at least one inflator comprises an inflator having a plurality of squibs including a first squib and a second squib that are each ignited in the event of a vehicle emergency, and the first squib and the second squib have different ignition timings in the event of the vehicle emergency.

9. An occupant protection device according to claim 8, wherein the second squib ignites 15 to 40 msec after the first squib.

10. An occupant protection device according to claim 8, further comprising a controller connected to the inflator, wherein, in the event of a vehicle emergency, the controller outputs an ignition signal to the first squib so that the first squib is ignited at a first timing, and outputs an ignition signal to the second squib so that the second squib is ignited at a second timing different from the first timing.

11. An occupant protection device as claimed in claim 1 or 2, wherein the airbag cushion is arranged on a seat pan and configured to inflate and deploy using the seat pan as a reaction surface.

12. The occupant protection device of claim 11, wherein said airbag cushion is attached to said seat pan by said at least one inflator.

13. An occupant protection device as claimed in claim 1 or 2, wherein, when an occupant is seated on said seat cushion in a normal posture and fastening a seat belt, the inflation of said airbag cushion encourages backward rotation of the occupant's waist.

14. An occupant protection device as described in claim 7, wherein the first timing is earlier than the second timing, and the second timing is a timing after the internal pressure of the airbag cushion has reached an initial peak value due to activation of the first inflator and has started to decrease but before it has reached its final decrease, and the internal pressure of the airbag cushion reaches a later peak value exceeding the initial peak value due to activation of the second inflator.

15. An occupant protection device as claimed in claim 1 or 2, wherein the top of the front portion of the airbag cushion is positioned higher than the top of the rear portion when the airbag cushion is inflated and deployed.

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