Crew protection devices

Abstract

The present invention provides an occupant protection device that suppresses the lifting of the occupant's lower limbs during a vehicle collision and accurately supports the occupant's upper body with an airbag. [Solution] The occupant protection device 10 includes an airbag 30 that is folded and stored, and is configured to inflate and deploy when inflation gas is supplied to catch the occupant M, and an inflator 24 that releases the inflation gas supplied to the airbag 30. When inflation is complete, the airbag 30 has an upper body portion 30a1 configured to catch the upper body MU of the occupant M, and a lower body portion 30a2 which is integrally formed with the upper body portion 30a1 and configured to catch the knee portion MN of the occupant M.

Description

Technical Field

[0001] The present invention relates to an occupant protection device that protects an occupant sitting on a vehicle seat.

Background Art

[0002] Conventionally, as an occupant protection device that protects an occupant sitting on a vehicle seat, a seat belt that restrains the occupant to the seat is widely known. Further, in Patent Document 1, a configuration is described in which an airbag is provided in a lap belt portion that restrains the waist of the occupant in the seat belt, and the upper body of the occupant is received and protected by the airbag.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, in order for an occupant to sit comfortably, vehicles have been increasing in number that provide a wide space in front of the seat to expand the space for the occupant's feet. However, when such a wide space is provided in front of the seat, when the vehicle collides, it is difficult for the lower limbs of the occupant to contact members inside the vehicle such as the seat in front of the occupant or the instrument panel. Therefore, when only the upper body of the occupant is received by the airbag as in the configuration of Patent Document 1, the lower limbs of the occupant may be lifted by the impact associated with the collision of the vehicle, and accordingly, the upper body of the occupant may swing and the upper body of the occupant may not be accurately received by the airbag.

[0005] Therefore, an object of the present invention is to provide an occupant protection device that suppresses the lifting of the lower limbs of the occupant during a vehicle collision and can accurately receive the upper body of the occupant with an airbag.

Means for Solving the Problems

[0006] A typical configuration of the occupant protection device according to the present invention for solving the above problems is an occupant protection device for protecting an occupant seated in a seat, comprising: an airbag that is folded and stored, and configured to inflate and deploy when an inflation gas is supplied to catch the occupant; and an inflator that releases the inflation gas supplied to the airbag, wherein the airbag, when fully inflated, has an upper inflation section configured to catch the occupant's upper body, and a lower inflation section integrally formed with the upper inflation section and configured to catch the occupant's lower limbs.

[0007] According to the occupant protection device of the present invention, the lifting of the occupant's lower limbs during a vehicle collision can be suppressed, and the occupant's upper body can be accurately caught by the airbag. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the seat. [Figure 2] This is a left side view of the seat. [Figure 3] This is a front view of the seat with the occupant seated and wearing the seatbelt. [Figure 4] This is a cross-section of an airbag unit and a seat belt. [Figure 5] This is a front view of the seat with the airbag inflated. [Figure 6] This is a left side view of the seat with the airbag inflated. [Figure 7] This is a perspective view of an airbag unit in an inflated state. [Figure 8] This is a front view of the seat with the airbag inflated. [Figure 9] This is a left side view of the seat, showing the airbag in its state after inflation has begun but before inflation is complete. [Figure 10] This is a left side view of the seat with the airbag fully inflated. [Figure 11]This is a perspective view of a check valve. [Modes for carrying out the invention]

[0009] (First Embodiment) The following describes the occupant protection device 10 according to the first embodiment of the present invention. Note that the dimensions, materials, shapes, and relative arrangements of the components described below are not intended to limit the scope of this invention to those unless otherwise specifically stated.

[0010] Furthermore, in the following explanation, the left-right direction refers to the left and right directions of the seat 1 where occupant M, who is the protected person of the occupant protection device 10, is seated, specifically the left and right directions as seen from occupant M seated on seat 1. The front-rear direction refers to the front and rear directions of seat 1, specifically the front and rear directions as seen from occupant M seated on seat 1. The up-down direction refers to the upward and downward directions in the vertical direction.

[0011] The occupant protection device 10 protects occupant M, who is seated in seat 1 of the vehicle 50, by catching them with an airbag 30. Figure 1 is a perspective view of seat 1. Figure 2 is a left side view of seat 1, showing occupant M seated in seat 1 with seat belt 11 fastened by a dashed line. Figure 3 is a front view of seat 1 with occupant M seated and seat belt 11 fastened. Figure 4 is a cross-sectional view of the airbag unit 70 and seat belt 11 cut along the AA section shown in Figure 3.

[0012] As shown in Figures 1 to 4, the occupant protection device 10 comprises a seat belt 11, an airbag unit 70 attached to the seat belt 11 and including an airbag 30, and an inflator 24 that supplies inflation gas to the airbag 30. The occupant protection device 10 also comprises a control device 22 that controls the operation of the inflator 24, and an acceleration sensor 21 used for detecting collisions of the vehicle 50.

[0013] The seat belt 11 is a belt-like member that restrains the occupant M to the seat 1, and in this embodiment, it is formed of a synthetic fiber such as nylon. The seat belt 11 is configured to be able to be drawn out from a winding mechanism 15 provided inside the vicinity of the upper left edge of the backrest portion 1a of the seat 1. The lower end portion of the seat belt 11 is fixed to an anchor member 17 provided on the left side of the seat portion 1b of the seat 1.

[0014] A tongue 18 is attached to an intermediate portion of the seat belt 11. The tongue 18 is fastened to a buckle 19 provided on the right side of the seat portion 1b of the seat 1. The state where the occupant M is seated on the seat 1 and the tongue 18 is fastened to the buckle 19 is the state where the seat belt 11 is worn by the occupant M. Incidentally, the occupant M can release the fastening of the tongue 18 to the buckle 19 by pressing a release button (not shown) provided on the buckle 19 and remove the tongue 18 from the buckle 19.

[0015] The winding mechanism 15 has a pretensioner mechanism 16 configured to stop the drawing out in the case of a sudden draw out of the seat belt 11 and to wind up the drawn out seat belt 11 in the event of a collision or the like of the vehicle 50. The pretensioner mechanism 16 winds up the seat belt 11 by rotating the shaft around which the seat belt 11 is wound by operating a built-in gas generator (not shown).

[0016] The seat belt 11 in the state of being worn by the occupant M has a shoulder belt portion 12 that extends from the tongue 18 toward the winding mechanism 15 side, is disposed in front of the upper body MU of the occupant M, and is configured to restrain the upper body MU, and a lap belt portion 13 that extends from the tongue 18 toward the anchor member 17 side, is disposed in front of the waist MW of the occupant M, and is configured to restrain the waist MW.

[0017] The acceleration sensor 21 is attached to a front bumper (not shown) of the vehicle 50, and detects an impact generated due to a collision or the like of the vehicle 50 as acceleration. The control device 22 includes a CPU, a memory, and the like, and is attached at a predetermined position inside the vehicle 50. The control device 22 is electrically connected to the acceleration sensor 21, the inflator 24, and the pretensioner mechanism 16. The control device 22 transmits an activation signal to the inflator 24 and the pretensioner mechanism 16 according to the detection result of the acceleration sensor 21.

[0018] The inflator 24 includes a substantially cylindrical gas generation part 24a that generates inflation gas inside, and a tubular pipe part 24b that guides the inflation gas released from the gas generation part 24a to the airbag 30. The gas generation part 24a is attached to the rear surface of a seat frame 1c that supports the seat part 1b of the seat 1 by bolts or the like (not shown). The pipe part 24b extends leftward from the gas generation part 24a and is bent in a substantially L shape along the bottom surface to the side surface of the seat part 1b. The inflator 24 operates to generate inflation gas when an activation signal is input from the control device 22.

[0019] Next, the configuration of the airbag unit 70 will be described. FIG. 5 is a front view of the seat 1 in a state where the airbag 30 is inflated. FIG. 6 is a left side view of the seat 1 in a state where the airbag 30 is inflated. In FIGS. 5 and 6, an occupant M sitting on the seat 1 and wearing the seat belt 11 is shown by a two-dot chain line. FIG. 7 is a perspective view of the airbag unit 70 in a state where the airbag 30 is inflated, and the airbag cover 73 of the airbag unit 70 is omitted.

[0020] As shown in FIGS. 4 to 7, the airbag unit 70 includes an airbag 30, a bag connection part 72 that connects the airbag 30 to the lap belt part 13, and an airbag cover 73 that covers the folded airbag 30 and the bag connection part 72.

[0021] The airbag 30 comprises a bag body 30a configured to inflate and deploy to catch the occupant M when inflation gas is supplied, and a conduit 30b that guides the inflation gas released from the inflator 24 to the inlet 30a1c1 of the bag body 30a. Before inflation gas is supplied, the bag body 30a is folded and housed inside the airbag cover 73 (see Figure 4). In this embodiment, the bag body 30a is made of a base fabric for bags, which is a woven fabric formed by plain weaving polyester fibers or the like.

[0022] When fully inflated, the bag body 30a consists of a roughly triangular prism-shaped upper body portion 30a1 (upper inflatable portion) configured to support the upper body MU of the occupant M, and a roughly rectangular parallelepiped-shaped lower body portion 30a2 (lower inflatable portion) integrally formed with the upper body portion 30a1 and configured to support the knee portion MN, which is part of the occupant M's lower limbs. The upper body portion 30a1 and the lower body portion 30a2 are separated internally by a horizontally extending partition wall 30a3 provided inside the bag body portion 30a. The partition wall 30a3 has a communication opening 30a3a, through which the upper body portion 30a1 and the lower body portion 30a2 communicate. In this embodiment, the partition wall 30a3 is formed from the base fabric for the bag and is sewn and fixed to the inner circumference of the bag body portion 30a. Furthermore, in this embodiment, the state in which the bag body 30a has completed inflation refers to the state in which the bag body 30a can fully perform its function, and refers to the state in which the bag body 30a is unfolded in a predetermined position and shape.

[0023] The upper main body portion 30a1 is positioned directly in front of the occupant M and opposite to the occupant M's upper body MU. It has a rear wall portion 30a1a that contacts and supports the occupant M's upper body MU as it attempts to move forward during a collision with the vehicle 50, and a front wall portion 30a1b positioned on the front side opposite to the rear wall portion 30a1a. The upper main body portion 30a1 also has a lower wall portion 30a1c positioned below and supported by the occupant M's thigh portion MF, a left wall portion 30a1d positioned on the left side, and a right wall portion 30a1e positioned on the right side. The lower wall portion 30a1c is provided with two inlets 30a1c1, which are openings for allowing the expansion gas in the conduit portion 30b to flow into the bag main body portion 30a.

[0024] The lower main body portion 30a2 is positioned directly in front of the occupant M and opposite to the occupant M's knee portion MN. It has a rear wall portion 30a2a that contacts and supports the occupant M's knee portion MN as it tries to lift upward during a collision with the vehicle 50, and a front wall portion 30a2b positioned on the front side opposite to the rear wall portion 30a2a. The outer periphery of the front wall portion 30a2b of the lower main body portion 30a2 is connected to the outer periphery of the front wall portion 30a1b of the upper main body portion 30a1, and the outer periphery of the rear wall portion 30a2a of the lower main body portion 30a2 is connected to the outer periphery of the lower wall portion 30a1c of the upper main body portion 30a1. The lower main body portion 30a2 also has a left wall portion 30a2c positioned on the left side and a right wall portion 30a2d positioned on the right side.

[0025] Furthermore, a cylindrical flow straightening member 30a4 (guide member) is provided inside the bag body 30a. The flow straightening member 30a4 is a member that takes in the expansion gas flowing into the bag body 30a from the inlet 30a1c1 formed in the lower wall portion 30a1c of the upper body portion 30a1 and guides it to the lower body portion 30a2. The flow straightening member 30a4 in this embodiment is made of the base fabric for the bag.

[0026] One longitudinal end of the rectifier member 30a4 is provided with two connection ports 30a4a, which are openings connected to the two inlets 30a1c1 of the upper main body 30a1. The other longitudinal end of the rectifier member 30a4 is an outlet 30a4b for discharging the expansion gas that has flowed into the cylinder of the rectifier member 30a4 from the connection ports 30a4a, and this outlet 30a4b is located inside the lower main body 30a2. The rectifier member 30a4 is fixed to the bag main body 30a by sewing the periphery of the connection ports 30a4a to the periphery of the inlets 30a1c1 of the upper main body 30a1.

[0027] Furthermore, the intermediate portion 30a4c of the rectifying member 30a4, which is the part between the longitudinal connection port 30a4a and the discharge port 30a4b, is inserted through the communication port 30a3a of the partition wall 30a3. Here, a gap 30a5 is provided between the outer circumference of the intermediate portion 30a4c of the rectifying member 30a4 and the inner wall of the communication port 30a3a of the partition wall 30a3. This allows the expansion gas to pass back and forth between the upper main body portion 30a1 and the lower main body portion 30a2 through the gap 30a5.

[0028] The conduit section 30b is a cylindrical member that extends along the longitudinal direction of the wrap belt section 13 and is made of the same bag base fabric as the bag body section 30a. One end 30b2 of the conduit section 30b in the longitudinal direction is connected to the pipe section 24b of the inflator 24, and the other end 30b3 is connected to the inlet 30a1c1 of the bag body section 30a.

[0029] Specifically, one end 30b2 of the conduit section 30b and the pipe section 24b of the inflator 24 are fastened together with a clamp 27, thereby connecting them in a way that prevents the expansion gas from leaking out. In addition, a communication port 30b1 is formed at the other end 30b3 of the conduit section 30b, which is an opening that communicates with the inlet 30a1c1 of the bag body section 30a. The periphery of the inlet 30a1c1 of the bag body section 30a and the periphery of the communication port 30b1 of the conduit section 30b are sewn together, so that the other end 30b3 of the conduit section 30b and the bag body section 30a are connected with the inlet 30a1c1 and the communication port 30b1 in communication. As a result, the expansion gas released from the inflator 24 into the conduit section 30b of the airbag 30 flows into the inside of the bag body section 30a via the communication port 30b1 and the inlet 30a1c1.

[0030] The bag connecting portion 72 is a member that connects the wrap belt portion 13 and the airbag 30, and in this embodiment, it is made of the same base fabric as the base fabric for the bag that forms the airbag 30. The bag connecting portion 72 is a through hole that runs through its longitudinal direction and has a belt insertion portion 72a through which the wrap belt portion 13 is inserted. The upper surface of the bag connecting portion 72 is sewn to the lower surface of the conduit portion 30b of the airbag 30. With this configuration, the wrap belt portion 13 and the airbag 30 are connected via the bag connecting portion 72.

[0031] The airbag cover 73 is a cylindrical member attached to the wrap belt portion 13, and in this embodiment, it is made of the same base fabric as the base fabric for the bag that forms the airbag 30. The airbag cover 73 houses the entire bag body portion 30a, a part of the conduit portion 30b, the entire bag connecting portion 72, and a part of the wrap belt portion 13 of the folded airbag 30 inside the cylinder. When the bag body portion 30a inflates, the airbag cover 73 receives pressure from the bag body portion 30a and ruptures to form an opening, allowing the bag body portion 30a to be unfurled through this opening.

[0032] Next, the occupant protection operation of the occupant protection device 10 will be described. First, when the vehicle 50 collides, the acceleration sensor 21 detects this collision as acceleration. If the acceleration detected by the acceleration sensor 21 is above a predetermined level, the control device 22 determines that the vehicle 50 has collided and sends an operation signal to the inflator 24 and the pretensioner mechanism 16.

[0033] Next, the pretensioner mechanism 16 is activated, and the seat belt 11 attached to occupant M is retracted by the pretensioner mechanism 16. As a result, the lap belt portion 13 of the seat belt 11 is pulled towards the tongue 18 and the shoulder belt portion 12 is pulled towards occupant M's shoulder, stabilizing occupant M's seated position.

[0034] Next, the inflator 24 activates and releases expansion gas, which flows into the bag body 30a through the conduit section 30b of the airbag 30 and into the bag body 30a through the two inlets 30a1c1. The expansion gas that has flowed into the bag body 30a is first guided by the flow straightening member 30a4 and supplied to the lower body 30a2. This causes the lower body 30a2 to begin expanding.

[0035] Next, some of the expansion gas supplied to the lower main body 30a2 flows into the upper main body 30a1 through the communication port 30a3a of the partition wall 30a3, specifically the gap 30a5 between the intermediate portion 30a4c of the rectifying member 30a4 and the inner wall of the communication port 30a3a. This causes the upper main body 30a1 to begin expanding. Subsequently, when more expansion gas is supplied to the upper main body 30a1 and the lower main body 30a2, the upper main body 30a1 and the lower main body 30a2 complete their expansion. In this way, the bag main body 30a completes its expansion.

[0036] As described above, the expansion gas that flows into the bag body 30a from the inlet 30a1c1 of the upper body 30a1 is guided by the flow straightening member 30a4 and first supplied to the lower body 30a2. Therefore, the timing of the lower body 30a2's expansion start is earlier than the timing of the upper body 30a1's expansion start, and the timing of the lower body 30a2's expansion completion is also earlier than the timing of the upper body 30a1's expansion completion.

[0037] Subsequently, the upper body MU of occupant M, which attempts to move forward due to the impact of the collision with vehicle 50, is caught by the upper body portion 30a1 of the bag body portion 30a, and the knee portion MN of occupant M, which attempts to be lifted upward, is caught by the lower body portion 30a2. In this way, the occupant protection device 10 protects occupant M.

[0038] Thus, in this embodiment, the airbag 30 has an upper body portion 30a1 configured to support the upper body MU of the occupant M when inflation is complete, and a lower body portion 30a2 integrally formed with the upper body portion 30a1 and configured to support the knee portion MN, which is part of the occupant M's lower limbs. This provides the following effects.

[0039] In other words, if there is ample space in front of seat 1, the lower limbs of occupant M are less likely to come into contact with the seat in front of occupant M, instrument panel, or other internal components of vehicle 50 during a collision with vehicle 50. Therefore, if the bag body 30a of the airbag 30 does not have a lower body 30a2 when fully inflated, the impact of the collision with vehicle 50 may cause occupant M's lower limbs to lift, and consequently, occupant M's upper body MU may swing, potentially preventing the airbag body 30a from properly catching occupant M's upper body MU.

[0040] In contrast, in this embodiment, as described above, the bag body portion 30a of the airbag 30 has a lower body portion 30a2 when inflation is complete, so that the lower limbs of the occupant M, which tend to be lifted upward by the impact of the collision with the vehicle 50, are received by the lower body portion 30a2. Therefore, the swinging of the upper body MU caused by the lifting of the occupant M's lower limbs is suppressed. Accordingly, the occupant protection device 10 of this embodiment can suppress the lifting of the occupant M's lower limbs during a collision with the vehicle 50, and can accurately receive the upper body MU of the occupant M with the airbag 30.

[0041] Furthermore, the bag body portion 30a of the airbag 30 is equipped with a flow straightening member 30a4 that guides the inflation gas that flows into the bag body portion 30a from the inlet 30a1c1 of the upper body portion 30a1 to the lower body portion 30a2. As a result, the inflation start timing of the lower body portion 30a2 is earlier than the inflation start timing of the upper body portion 30a1, and the inflation completion timing of the lower body portion 30a2 is also earlier than the inflation completion timing of the upper body portion 30a1. With this configuration, the lower body portion 30a2 can receive the lower limbs of the occupant M at an early stage, stabilizing the occupant M's posture, and then the upper body portion 30a1 can receive the occupant M's upper body MU, allowing the airbag 30 to receive the occupant M's upper body MU more accurately.

[0042] (Second Embodiment) Next, an occupant protection device 10 according to a second embodiment of the present invention will be described. Parts that overlap with the description of the first embodiment will be omitted, using the same drawings or reference numerals.

[0043] The configuration of the occupant protection device 10 according to this embodiment differs from the configuration of the occupant protection device 10 according to the first embodiment only in that a flow straightening member 30a4 is not provided inside the bag body portion 30a of the airbag 30, and instead a check valve 30a6 is provided. In other words, the configuration of the occupant protection device 10 according to this embodiment is the same as the configuration of the first embodiment except for the internal structure of the bag body portion 30a. Therefore, the following will mainly describe the internal structure of the bag body portion 30a, and other descriptions will be omitted as appropriate.

[0044] Figure 8 is a front view of seat 1 with the airbag 30 inflated. Figure 9 is a left side view of seat 1 after the airbag 30 has started to inflate but before it has finished inflating. Figure 10 is a left side view of seat 1 with the airbag 30 fully inflated. In Figures 8 to 10, the occupant M, seated in seat 1 and fastened with a seat belt 11, is shown by a dashed line. Figure 11 is a perspective view of check valve 30a6, where Figure 11A shows the valve portion 30a6c of check valve 30a6 in a closed state, and Figure 11B shows the valve portion 30a6c of check valve 30a6 in an open state.

[0045] Similar to the occupant protection device 10 according to the first embodiment, the bag body 30a of the occupant protection device 10 according to this embodiment, when fully inflated, consists of a roughly triangular prism-shaped upper body 30a1 (upper inflatable part) configured to receive the upper body MU of the occupant M, and a roughly rectangular parallelepiped-shaped lower body 30a2 (lower inflatable part) integrally formed with the upper body 30a1 and configured to receive the knee portion MN, which is part of the lower limbs of the occupant M.

[0046] The upper body portion 30a1 and the lower body portion 30a2 are separated internally by a horizontally extending partition wall 30a3 provided inside the bag body portion 30a. The partition wall 30a3 has a communication opening 30a3a, through which the upper body portion 30a1 and the lower body portion 30a2 communicate. The partition wall 30a3 in this embodiment is formed from the base fabric for the bag and is sewn and fixed to the inner circumference of the bag body portion 30a.

[0047] Furthermore, a check valve 30a6 is provided at the communication opening 30a3a of the partition wall 30a3. In this embodiment, the check valve 30a6 is formed from the base fabric for the bag described above. The check valve 30a6 has a base portion 30a6a that extends horizontally and is partially sewn and fixed to the periphery of the communication opening 30a3a of the partition wall 30a3, a slit portion 30a6b formed in the base portion 30a6a, and a cylindrical valve portion 30a6c that extends downward from the slit portion 30a6b and is inserted into the communication opening 30a3a of the partition wall 30a3. The slit portion 30a6b is located inside the upper main body portion 30a1.

[0048] The valve portion 30a6c of the check valve 30a6 is closed before expansion gas is supplied to the bag body 30a, thereby sealing the communication port 30a3a of the partition wall 30a3. The valve portion 30a6c is opened when a predetermined amount of expansion gas flows into the upper body 30a1 from the inlet 30a1c1, causing the internal pressure of the upper body 30a1 to rise. This releases the seal on the communication port 30a3a by the check valve 30a6, allowing the upper body 30a1 and the lower body 30a2 to communicate.

[0049] Furthermore, as described above, the valve portion 30a6c of the check valve 30a6 opens as the internal pressure of the upper body portion 30a1 rises, and then closes again as the internal pressure of the lower body portion 30a2 rises when an amount of expansion gas exceeding a predetermined level flows from the upper body portion 30a1 to the lower body portion 30a2 through the communication port 30a3a. This seals the communication port 30a3a of the partition wall 30a3 again, restricting the inflow of expansion gas from the lower body portion 30a2 to the upper body portion 30a1. In other words, the check valve 30a6 seals the communication port 30a3a when an amount of expansion gas exceeding a predetermined level flows into the lower body portion 30a2, thereby restricting the inflow of expansion gas from the lower body portion 30a2 to the upper body portion 30a1.

[0050] The upper main body portion 30a1 is positioned directly in front of the occupant M and opposite to the occupant M's upper body MU. It has a rear wall portion 30a1a that contacts and supports the occupant M's upper body MU as it attempts to move forward during a collision with the vehicle 50, and a front wall portion 30a1b positioned on the front side opposite to the rear wall portion 30a1a. The upper main body portion 30a1 also has a lower wall portion 30a1c positioned below and supported by the occupant M's thigh portion MF, a left wall portion 30a1d positioned on the left side, and a right wall portion 30a1e positioned on the right side. The lower wall portion 30a1c is provided with two inlets 30a1c1, which are openings for allowing expansion gas from the conduit portion 30b to flow in.

[0051] The lower main body portion 30a2 is positioned directly in front of the occupant M and opposite to the occupant M's knee portion MN. It has a rear wall portion 30a2a that contacts and supports the occupant M's knee portion MN as it tries to lift upward during a collision with the vehicle 50, and a front wall portion 30a2b positioned on the front side opposite to the rear wall portion 30a2a. The outer periphery of the front wall portion 30a2b of the lower main body portion 30a2 is connected to the outer periphery of the front wall portion 30a1b of the upper main body portion 30a1, and the outer periphery of the rear wall portion 30a2a of the lower main body portion 30a2 is connected to the outer periphery of the lower wall portion 30a1c of the upper main body portion 30a1. The lower main body portion 30a2 also has a left wall portion 30a2c positioned on the left side and a right wall portion 30a2d positioned on the right side.

[0052] Next, the occupant protection operation of the occupant protection device 10 of this embodiment will be described. First, when the vehicle 50 collides, the acceleration sensor 21 detects this collision as acceleration. If the acceleration detected by the acceleration sensor 21 is above a predetermined level, the control device 22 determines that the vehicle 50 has collided and transmits an operation signal to the inflator 24 and the pretensioner mechanism 16.

[0053] Next, the pretensioner mechanism 16 is activated, and the seat belt 11 attached to occupant M is retracted by the pretensioner mechanism 16. As a result, the lap belt portion 13 of the seat belt 11 is pulled towards the tongue 18 and the shoulder belt portion 12 is pulled towards occupant M's shoulder, stabilizing occupant M's seated position.

[0054] Next, the inflator 24 activates and releases expansion gas, which flows into the bag body 30a through the conduit section 30b of the airbag 30 and into the bag body 30a through the two inlets 30a1 and c1. The expansion gas that flows into the bag body 30a is first supplied to the upper body 30a1, which causes the upper body 30a1 to begin expanding.

[0055] Next, when a predetermined amount of expansion gas flows into the upper body portion 30a1, the valve portion 30a6c of the check valve 30a6, which was previously closed, opens. This releases the seal on the communication port 30a3a by the check valve 30a6, and the upper body portion 30a1 and the lower body portion 30a2 communicate through the communication port 30a3a. Then, a portion of the expansion gas inside the upper body portion 30a1 is supplied to the lower body portion 30a2 via the slit portion 30a6b, valve portion 30a6c, and communication port 30a3a of the check valve 30a6.

[0056] Next, a predetermined amount of expansion gas is supplied to the lower body portion 30a2, and once the expansion of the lower body portion 30a2 is complete, the valve portion 30a6c of the check valve 30a6 is closed, and the communication port 30a3a of the partition wall 30a3 is sealed again by the check valve 30a6. After that, when expansion gas is further supplied to the upper body portion 30a1, the upper body portion 30a1 completes its expansion. In this way, the bag body portion 30a completes its expansion.

[0057] Subsequently, the upper body MU of occupant M, which attempts to move forward due to the impact of the collision with vehicle 50, is caught by the upper body portion 30a1 of the bag body portion 30a, and the knee portion MN of occupant M, which attempts to be lifted upward, is caught by the lower body portion 30a2. In this way, the occupant protection device 10 protects occupant M.

[0058] As described above, in this embodiment, the airbag 30 has an upper body portion 30a1 configured to receive the upper body MU of the occupant M when inflation is complete, and a lower body portion 30a2 integrally formed with the upper body portion 30a1 and configured to receive the knee portion MN, which is part of the lower limbs of the occupant M. As a result, similar to the occupant protection device 10 according to the first embodiment, the lower body portion 30a2 receives the lower limbs of the occupant M that tend to lift upward due to the impact of a collision with the vehicle 50. Therefore, the swinging of the upper body MU caused by the lifting of the lower limbs of the occupant M is suppressed. Accordingly, the occupant protection device 10 of this embodiment can suppress the lifting of the lower limbs of the occupant M during a collision with the vehicle 50 and accurately receive the upper body MU of the occupant M with the airbag 30.

[0059] Furthermore, the airbag body 30a of the airbag 30 is equipped with a check valve 30a6 that seals the communication port 30a3a when an amount of inflation gas exceeding a predetermined level flows into the lower body 30a2, thereby restricting the flow of inflation gas from the lower body 30a2 to the upper body 30a1. This increases the internal pressure of the upper body 30a1 and enhances the reaction force of the upper body 30a1, allowing the upper body 30a1 to more accurately support the upper body MU of the occupant M, which is heavier than the lower limbs.

[0060] Although the first and second embodiments described configurations in which the airbag 30 is provided on the lap belt portion 13 of the seat belt 11, the present invention is not limited thereto. That is, the airbag 30 may be provided in other positions as long as the airbag 30 has an upper body portion 30a1 configured to support the upper body MU of the occupant M when inflation is complete, and a lower body portion 30a2 formed integrally with the upper body portion 30a1 and configured to support the lower limbs of the occupant M.

[0061] For example, the airbag unit 70 may be attached to the shoulder belt portion 12 of the seat belt 11 in the same manner as described above, thereby providing the airbag 30 to the shoulder belt portion 12. Alternatively, the airbag 30 may be provided to the backrest portion 1a or seat portion 1b of the seat 1 instead of the seat belt 11. The same effects as described above can be obtained even with such a configuration.

[0062] Furthermore, although the occupant protection device 10 was described in the first and second embodiments using a so-called three-point seat belt 11 having a shoulder belt portion 12 and a lap belt portion 13 as an example, the present invention is not limited thereto. That is, even if the present invention is applied to a so-called two-point seat belt 11 having a lap belt portion 13 but no shoulder belt portion 12, the same effects as described above can be obtained. [Explanation of Symbols]

[0063] 1...Seat, 10...Occupant protection device, 11...Seat belt, 13...Wrap belt section, 24...Inflator, 30...Airbag, 30a1...Upper main body (upper inflation section), 30a1c1...Inlet, 30a2...Lower main body (lower inflation section), 30a3...Bulkhead, 30a3a...Communication port (opening), 30a4...Flow straightening member (guide member), 30a4a...Connection port, 30a4b...Discharge port, 30a6...Check valve, M...Occupant, MN...Knee (lower limb), MU...Upper body, MW...Waist

Claims

1. An occupant protection device that protects occupants seated in a seat, An airbag that is folded and stored, and is configured to inflate and deploy when inflation gas is supplied to catch the occupant, An inflator that releases the inflation gas supplied to the airbag, Equipped with, When inflation is complete, the airbag An upper inflatable section configured to support the upper body of the aforementioned occupant, A lower inflatable portion is integrally formed with the upper inflatable portion and configured to support the lower limbs of the occupant, A occupant protection device characterized by having the following features.

2. The airbag has a partition wall inside that separates the upper inflation section and the lower inflation section. The occupant protection device according to claim 1, characterized in that the upper expansion portion and the lower expansion portion are in internal communication through an opening formed in the bulkhead.

3. The aforementioned airbag, An inlet is provided in the upper expansion section for allowing the expansion gas released from the inflator to flow into the interior, A cylindrical guide member for guiding the inflation gas that flows into the airbag from the inlet to the lower inflation section, the guide member having a connection port connected to the inlet and an outlet located inside the lower inflation section for discharging the inflation gas that flows into the guide member from the connection port, The occupant protection device according to claim 2, characterized by comprising:

4. The occupant protection device according to claim 2, characterized in that the opening is provided with a check valve that restricts the inflow of the expansion gas from the lower expansion section to the upper expansion section when a predetermined amount of the expansion gas flows into the lower expansion section.

5. A seat belt for restraining the occupant to the seat, comprising a seat belt portion configured to restrain the occupant's waist, The occupant protection device according to any one of claims 1 to 4, characterized in that the airbag is attached to the lap belt portion.

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