JP4389636B2 - Air bag device for knee protection - Google Patents

Description

  The present invention relates to a knee protection airbag device in which an airbag that expands and inflates by inflating gas can protect a knee of a passenger such as a driver or a passenger on a passenger seat.

  2. Description of the Related Art Conventionally, in a knee protection airbag device that protects a passenger's knee, such as a driver, an airbag that is folded so as to be deployed and inflatable on the front side of a seated passenger's knee, and an inflator that supplies inflation gas to the airbag And a case for storing and holding the folded airbag and the inflator. The inflator is a cylindrical cylinder type housed in an airbag, and a diffuser that rectifies the inflation gas discharged from the inflator is disposed around the inflator (see, for example, Patent Document 1).

  In addition, the inflator is mounted on the vehicle with a gas discharge port for discharging the inflation gas disposed at one end, and the axial direction along the left-right direction.

The diffuser allows the inflation gas from the gas discharge port of the inflator disposed at the end in the left-right direction to flow in the left-right direction of the case so that the folded and stored airbag is evenly expanded and inflated left and right. A plurality of openings are provided along the left-right direction to allow the inflation gas to flow out from the gas discharge port so that the gas flows in the airbag evenly from side to side with respect to the vicinity of the center. Adjustments were made so that the side closer to the outlet was smaller and the side away from the gas outlet was larger.
JP 2003-170800 A

  However, in the conventional airbag device for knee protection, since the inflation gas is rectified in the portion close to the inflator in the airbag, that is, the position in the case, the inflation portion that protects the knee of the airbag is If it is placed on the upper edge of the airbag that protrudes from the case, if it collides with the inner peripheral surface of the case and the flow of the inflation gas changes, it will be used for inflation at the knee protection inflation part away from the case There is a possibility that the gas pressure may not be approximately equal in each part along the left-right direction. Furthermore, if a tether that regulates the thickness at the time of completion of inflation is disposed in the airbag, the tether changes the flow of the inflation gas in cooperation with the cancellation of the folding, and the knee protection inflation portion There is also a risk of promoting non-uniform gas pressure.

  Then, when the gas pressure in the knee protection inflatable portion is uneven, the occupant approaches immediately before the airbag is completely inflated, and the knee interferes with the high gas pressure portion in the knee protective inflatable portion. In this case, the knee protection inflatable part can protect the vicinity of the knee in the event of a vehicle collision, but there is room for improvement in order to further protect the vicinity of the knee. was there.

  The present invention solves the above-mentioned problem, and the gas pressure in the knee protection inflating portion of the airbag in the middle of deployment and inflation can be made substantially uniform at each site along the left-right direction, and approaches. An object of the present invention is to provide a knee protection airbag device capable of accurately protecting the vicinity of a passenger's knee.

The airbag device for knee protection according to the present invention is configured to inflate inflation gas so as to be able to protect an occupant's knee, project from the storage portion to the vehicle rear side, and expand and expand upward.
An airbag body having an occupant side wall portion located on the occupant side at the time of completion of inflation, and a vehicle body side wall portion located on the vehicle body side;
A tether that connects the occupant side wall and the vehicle body side wall to regulate the thickness of the airbag body when the inflation is completed;
An airbag comprising:
A knee protection airbag device comprising:
The airbag body is configured to dispose a knee protection inflatable portion on the upper edge side when the inflation is completed,
The inner periphery of the airbag body along the left-right direction so that the tether divides the interior of the airbag body vertically below the knee protection inflatable portion at the position where the tether is separated from the storage part of the airbag body when inflation is completed. It is connected to the entire area of the surface, and has a plurality of gas circulation holes, and is arranged,
The opening area is adjusted so that the gas pressure of the gas for inflation in the knee protection inflatable portion is substantially equal in each part along the left-right direction, and the air bag body at the time of completion of inflation It is characterized in that it is disposed away from the inner peripheral surface of the airbag body as a position deviating from the front side of the position of interference with the occupant's shin .

  In the knee protection airbag device according to the present invention, the tethers below the knee protection inflatable portion have the opening areas of the plurality of gas flow holes adjusted, and when the airbag body is deployed and inflated, the plurality of gas flow holes The pressure of the inflation gas flowing into the knee protection inflatable part after passing through is substantially uniform at each part along the left-right direction, so that the knee protection inflatable part interferes with the vicinity of the occupant's knee approaching during the inflation. However, it is possible to protect the vicinity of the knee accurately without pressing the vicinity of the knee unnecessarily.

  In particular, since these gas flow holes are away from the inner peripheral surface of the airbag body and are not in contact with the inner peripheral surface of the airbag body, the gas pressure can be adjusted accurately by adjusting the opening area. By the way, if a part of the periphery of the gas flow hole is constituted by the inner peripheral surface of the airbag body, the gas flow hole is guided by the inner peripheral surface of the airbag body and passes through the inflation gas. It is difficult to adjust the gas pressure by adjusting the opening area.

  And since the tethers whose opening areas of the plurality of gas circulation holes are adjusted are arranged at the positions of the free spaces separated from the storage parts in the airbag main body when the inflation is completed, the inner peripheral surface side of the case and The expansion gas can flow upward through the gas flow holes in the rectified state without being affected by the expansion gas that has changed its flow due to the collision, and the gas pressure is dispersed as much as possible. First, the gas pressure in the knee protection inflatable portion can be made substantially uniform at each portion along the left-right direction for each airbag.

  In the airbag of the airbag device according to the present invention, the lower portion of the airbag main body partitioned by the tether arranged in the left-right direction is inflated widely, and the airbag on the upper side of the tether is Since the upper part of the bag body begins to inflate, the airbag body expands and expands widely and expands upward, and the lower part of the airbag body moves forward before deployment is completed. It is possible to protect the shin below the knee with good cushioning properties.

  Therefore, in the airbag device for knee protection according to the present invention, the gas pressure in the knee protection inflating portion of the airbag in the middle of deployment and inflation can be made substantially uniform at each portion along the left-right direction, and approached. The area around the knees of the passengers can be protected accurately.

Furthermore , the gas flow hole is disposed at a position away from the front side of the position of interference with the occupant's shin in the airbag body when the inflation is completed.

  That is, at the position where the gas circulation holes are arranged in the tether, the tether is easy to extend, and it is difficult to avoid increasing the distance between the occupant side and the side wall of the vehicle body from the other parts and increasing the thickness of the airbag body. If the gas flow hole is located away from the position where it interferes with the shin, the shin of the passenger and the occupant's shin should be properly protected by the airbag body without unnecessarily pressing the shin. Can do.

  Further, if the tethers in the airbag body are arranged in a plurality of stages in the vertical direction, the rectifying action of the inflation gas passing through the gas flow holes of each tether can be enhanced, and further during the deployment and expansion. The gas pressure in the knee protection inflatable portion of the airbag body can be made uniform at each part along the left-right direction. Furthermore, the thickness of the airbag main body at the time of completion of inflation can be regulated by each part, and it is easy to maintain the overall plate shape of the airbag main body at the time of completion of inflation by eliminating partial swelling.

  In this case, the area from the lower edge side of the airbag body at the time of completion of the inflation to at least immediately below the knee protection inflating portion may be folded through a roll folding process in which the upper edge side is roll-folded on the side wall portion of the vehicle body. desirable.

  In other words, even when the gas flow holes of the tethers arranged in a plurality of stages in the vertical direction coincide with each other in the vertical direction, such folding of the airbag body unwinds the roll fold when the folding is canceled. In the state, the expansion gas is obstructed by the roll folding part, and it becomes difficult to directly enter the gas flow hole at the upper position, and the gas pressure is increased at each part along the left and right direction in the knee protection expansion part. Does not impede the action and effect of making it approximately equal. Furthermore, this roll folding part is formed by roll-folding the upper edge side on the side of the vehicle body side wall, and when unfolding and unfolding upward, even if the space between the passenger and the vehicle body is narrow, the passenger side It is easy to complete the deployment by approaching the vehicle body side while suppressing the protrusion to the vehicle body.

  In this case, before the roll folding process, the knee protection inflatable portion is desirably folded through an upper edge folding process in which the upper edge side is folded into the airbag body so that the upper edge side approaches the lower edge side of the airbag body. .

  In such a configuration, the occupant side wall portion and the vehicle body side wall portion near the upper edge of the airbag body are merely folded in the front-rear direction of the vehicle. As a result, the upper edge easily protrudes upward, and the folding is quickly eliminated. In addition, even if the occupant side wall portion and the vehicle body side wall portion around the upper edge folded into the airbag body come into contact with the vicinity of the knee or the vehicle body and the frictional resistance is large, the vicinity of the knee or the vehicle body Then, the upper edge of the airbag body that is not in direct contact easily and quickly protrudes upward. Therefore, if the area on the upper edge side of the airbag body during deployment that interferes with the vicinity of the knee in the airbag body is folded into the airbag body, the vicinity of the passenger's knee is very close to the knee protection airbag device. However, the upper edge side of the airbag body easily enters the narrow gap between the vicinity of the knee and the vehicle body by the inflow of the inflation gas, completes the deployment, and further, by the inflow of the inflation gas It expands thickly and can protect the knee area accurately.

  When the airbag main body is configured to flow inflating gas from one side in the left-right direction on the lower edge side of the airbag main body when inflation is completed, a plurality of gas circulations are provided. The holes may be arranged by adjusting the opening area so that the side close to the inflow position of the expansion gas is small and the side away from the inflow position of the expansion gas is large.

  In such a configuration, a cylinder type inflator in which a gas discharge port is arranged on the end side with respect to the case as a storage part for storing the airbag, the axial direction thereof is along the left-right direction of the case, The present invention can be applied to a knee protecting airbag device that is configured to be held. That is, in such a knee protection airbag device, even if an inflator is provided outside the case or in the airbag body, the inflation gas flowing in from the axial end of the inflator is not completely inflated. However, even in such a case, the gas pressure in the knee protection inflating part of the airbag body during the deployment and inflation is reduced in the left-right direction. It can be made substantially uniform at each part along, and the vicinity of the occupant's knee approaching can be protected accurately.

  In such a knee protection airbag device, a cylinder type inflator can be used to dispose the inflator within the width of the case in the left-right direction. And can be configured compactly.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The knee protection airbag device S according to the embodiment can protect a knee K (KL / KR) of a driver M as an occupant. -As shown in 4, it is arrange | positioned under the steering column 2 which is the driver | operator's M vehicle front side.

  In addition, the upper and lower sides, the left and right, and the front and rear in this specification correspond to the upper and lower, left and right, and front and rear of the vehicle when the knee protection airbag device S is mounted on the vehicle.

  As shown in FIG. 1, the steering column 2 includes a column main body 3 connected to the steering wheel 1 and a column cover 6 disposed so as to cover the column main body 3 below the steering wheel 1. Has been. The column main body 3 includes a main shaft 4 and a column tube 5 that covers the periphery of the main shaft 4.

  The column cover 6 is made of a synthetic resin having a substantially rectangular tube shape, and is disposed along the axial direction of the column body 3 so as to cover the column body 3. A rear surface 6a of a portion of the column cover 6 that protrudes from an instrument panel (hereinafter abbreviated as “instrument panel”) 8 has a substantially rectangular plate shape, and is formed in a curved shape that rises rearward in the vehicle front-rear direction.

  The knee protection airbag device S includes a folded airbag 39, an inflator 26 that supplies inflation gas to the airbag 39, a case 11 that houses the folded airbag 39 and opens the rear side of the vehicle. 11 is provided with a retainer 19 for attaching the airbag 39, and an airbag cover 32 for covering the rear side of the opening 11a of the airbag 39 in the case 11 for the vehicle.

  As shown in FIGS. 1 to 3, the case 11 is made of sheet metal and is disposed on the lower side of the steering column 2. The case 11 has a bottomed box shape, and extends from the outer peripheral edge of the bottom wall portion 15 to the rear side in a substantially rectangular tube shape, with a substantially rectangular plate-like bottom wall portion 15 disposed on the front end side of the case 11. In addition, the peripheral wall portion 12 is configured to be provided with a protruding opening 11a of the substantially rectangular airbag 39 at the rear end. A plurality of locking claws 13 for assembling the airbag cover 32 to the case 11 project from the outer surface side of the wall portions 12 a and 12 b facing the top and bottom of the peripheral wall portion 12. In the case of the embodiment, a plurality of the locking claw portions 13 are arranged on the upper wall portion 12a and the lower wall portion 12b (four in the case of the embodiment), and the tip 13a is bent forward of the vehicle. Thus, the distal end 13a side can be locked to the peripheral edge of the locking hole 35c formed in the upper and lower wall portions 35a and 35b of the side wall portion 35 described later of the airbag cover 32. In the case of the embodiment, each locking claw portion 13 is formed with a predetermined cut in the upper and lower wall portions 12a and 12b, and is cut and raised from the upper and lower wall portions 12a and 12b. It is formed integrally with the walls 12a and 12b.

  A substantially rectangular shape in which a retainer 22 (to be described later) of the retainer 19 can be inserted into an end portion side of the vehicle inner side I (the connector 29 side of the inflator 26, see FIG. 3) in the bottom wall portion 15, that is, the left edge side in the embodiment. An insertion hole 15a that is open in the front is formed so as to penetrate along the front-rear direction. In addition, the bottom wall 15 protrudes toward the vehicle front side (the inflator 26 side) on the end side of the vehicle outer side O (the head 28 side of the inflator 26), that is, the right edge side, and the head of the inflator 26 described later. A guide channel 17 that can cover the periphery of the portion 28 is provided. Furthermore, a through-hole 15 b for inserting a bolt 21 (described later) of the retainer 19 is formed in a portion of the bottom wall portion 15 that is on the vehicle outer side O from the guide flow path 17.

  The guide channel 17 guides the inflation gas G from the gas discharge port 28a disposed in the head portion 28 of the inflator 26 to the inflow opening 43 of the airbag body 40. A part of the right edge side of the wall portion 15 is formed so as to protrude to the front side of the vehicle, and has a substantially rectangular parallelepiped box shape with the rear side opened. An insertion hole 17 b for inserting the head 28 of the inflator 26 into the guide channel 17 is provided in the wall portion 17 a of the vehicle interior I in the guide channel 17.

  The case 11 is provided with a plurality of mounting brackets (not shown) for mounting and fixing the case 11 to the vehicle body side at predetermined positions of the peripheral wall portion 12, and these mounting brackets are arranged on the vehicle body side. It is attached and fixed to an instrument panel reinforcement (not shown) or the like disposed in the box.

  As shown in FIGS. 2, 3, and 6, the retainer 19 is made of sheet metal, and includes a substrate portion 20 and a holding portion 22 that is disposed so as to protrude from the substrate portion 20 and is connected to the inflator 26. It is prepared for. The substrate portion 20 is formed in a rectangular plate shape slightly smaller than the bottom wall portion 15 of the case 11, and sandwiches the vicinity of the periphery of the inflow opening 43 of the airbag 39 between the rear surface of the bottom wall portion 15 and the airbag. It is comprised so that the opening 43 periphery of 39 may be hold | maintained. A substantially square communication hole 20 a that communicates with the guide channel 17 and the opening 43 of the airbag 39 is formed in the substrate portion 20 at a position corresponding to the guide channel 17. A bolt 21 is provided on the right end side beyond the communication hole 20a of the base plate 20 so as to protrude toward the front of the vehicle and to fix the retainer 19 to the bottom wall 15 in an auxiliary manner. Further, a reinforcing rib 20b extending to the rear side of the vehicle is formed on the outer peripheral edge of the substrate portion 22.

  The holding portion 22 extends from the base plate portion 20 through the bottom wall portion 15 of the case 11 and the airbag 39 and is connected to the inflator 26, and the retainer 19 is attached to the case 11 using the inflator 26 as a scissors. Is. And in the case of embodiment, the holding | maintenance part 22 is made into the cross-sectional mouth shape which protrudes in the vehicle front side of the case 11 through the insertion hole 15a arrange | positioned in the bottom wall part 15, and the insertion hole 44 of the airbag 39. The pressing pieces 22a and 22a that can press the inflator 26 toward the case bottom wall 15 are caulked above and below the front end. The main body 27 of the inflator 26 is stepped by a concave groove that can prevent the inflator 26 from coming out of the guide channel 17 when the pressing pieces 22a and 22a are caulked and the inflator 26 is held by the holding unit 22. A portion 27a is formed.

  The inflator 26 is a cylinder type, and is disposed outside the bottom wall portion 15 on the front side of the case 11 with the axial direction extending in the left-right direction, as shown in FIGS. The inflator 26 includes a substantially columnar main body 27 and a head 28 disposed on one end side of the main body 27. The head portion 28 has a smaller diameter than the main body portion 27 and includes a plurality of gas discharge ports 28 a that can discharge the expansion gas G on the outer peripheral surface. Further, a connector 29 to which an operation signal input lead wire 30 is connected is connected to an end portion of the main body portion 27 away from the head portion 28. Further, a stepped portion 27 a made of a concave groove that can be engaged with each pressing piece 22 a of the holding portion 22 is formed at a portion of the main body portion 27 where the holding portion 22 is disposed.

  The inflator 26 according to the embodiment has a length dimension slightly smaller than the width dimension of the case bottom wall portion 15 in the left-right direction, and the head 28 is positioned at one end side in the left-right direction of the bottom wall portion 15 (in the embodiment, It is arranged so as to be offset toward the right edge side which becomes the vehicle outer side O).

  As shown in FIGS. 2 to 4, the airbag cover 32 is formed of an olefin-based thermoplastic elastomer, configured to cover the vehicle rear side of the case 11, and assembled to the case 11. The airbag cover 32 is disposed on the lower panel 8b side of the instrument panel 8 including the upper panel 8a and the lower panel 8b, and a door disposition portion 34 disposed near the protruding opening 11a of the case 11; And a general part 33 arranged around the door arrangement part 34.

  A lower panel 8 b is disposed around the door arrangement portion 34 adjacent to the door arrangement portion 34. In the case of the embodiment, the door arrangement portion 34 and the lower panel 8b are arranged such that the surface on the vehicle rear side is substantially flush (see FIGS. 2 and 3). And the door arrangement | positioning part 34 is arrange | positioned in the site | part which becomes the periphery of the door part 38 and the door part 38, and is a substantially square cylindrical side wall arrange | positioned so that the upper and lower sides and right and left of the case surrounding wall part 12 may be covered. And a portion 35.

  The door portion 38 is formed slightly larger than the opening 11a of the case 11 and has a substantially rectangular plate shape covering the opening 11a. In the embodiment, the door portion 38 includes two door portions 38 that open in the vertical direction. These door portions 38 are provided with hinge portions 37 serving as rotation centers at the time of opening at the upper end and the lower end, and at portions that are substantially H-shaped when viewed from the vehicle rear side around the door portion 38. A thin-walled fracture portion 36 is arranged.

  The upper and lower wall portions 35a and 35b of the side wall portion 35 are assembled pieces for assembling the airbag cover 32 to the case 11, and the locking claws 13 formed on the case peripheral wall portion 12 are respectively locked to the periphery. A locking hole 35c that is opened in a substantially rectangular shape is provided.

  As shown in FIGS. 2 and 3, the general portion 33 is located on the vehicle front side from the door disposition portion 34 by the thickness of the lower panel 8 b so as not to interfere with the lower panel 8 b disposed around the door disposition portion 34. It is formed so as to be recessed.

  The air bag 39 is formed from a woven fabric made of flexible polyester, polyamide yarn, or the like as shown in FIGS. 1 to 9, and is disposed in the air bag body 40 and the air bag body 40. And tethers 56 and 57 for regulating the thickness of the airbag main body 40 when the inflation is completed.

  The airbag body 40 has a substantially rectangular plate shape as shown in the two-dot chain lines of FIGS. 1 and 4 and FIGS. 5 and 6 and the knee KL of the driver M as an occupant. The shape has a width dimension in the left-right direction that can protect the KR.

  The airbag body 40 is configured as a knee protection inflatable portion 47 on the upper edge 40a side at the time of completion of deployment and as a shin protection inflation portion 48 below the knee protection inflation portion 47, and as an occupant at the time of completion of deployment. A vehicle body side wall portion 41 located on the vehicle body side column cover 6 side and a vehicle body side wall portion 42 located on the vehicle body side column cover 6 side. It is an airbag. Further, in the case of the embodiment, the airbag main body 40 is formed by using a single woven fabric, folded on the lower edge 40b side at the time of completion of deployment and stitched together. .

  In the case of the embodiment, the length dimension L0 in the vertical direction of the knee protection inflatable portion 47 at the completion of the expansion is about 180 to 200 mm.

Further, an inflow opening 43 and insertion holes 44 and 45 are formed in a portion of the vehicle body side wall portion 42 on the lower edge 40b side of the airbag body 40 when the inflation is completed (see FIGS. 3 and 10). The inflow opening 43 corresponds to the guide channel 17 and the communication hole 20a of the retainer 19, and is disposed at a position on the right edge 40d side of the airbag body 40 and is discharged from the gas discharge port 28a of the inflator 26. The inflation gas G will flow into the airbag body 40. The insertion hole 44 is for inserting the holding portion 22 of the retainer 19 and is disposed at a position on the left edge 40 c side of the airbag body 40. The insertion hole 45 is for inserting the bolt 21 of the retainer 19 and is disposed on the right edge 40 d side from the inflow opening 43. The airbag main body 40 projects the holding portion 22 of the retainer 19 from the insertion hole 44 and projects the bolt 21 of the retainer 19 from the insertion hole 45, so that the periphery of the opening 43 extends between the case bottom wall portion 15 and the retainer 19. The substrate 11 is sandwiched between and attached to the case 11.

  Further, the tethers 56 and 57 are arranged in two upper and lower stages so as to connect the occupant side wall 41 and the vehicle body side wall 42 of the airbag body 40. These tethers 56 and 57 are sewn and connected to the entire area of the inner peripheral surface 40e of the airbag body 40 along the left-right direction so as to divide the interior of the airbag body 40 vertically. A circulation hole 58 is provided and disposed. Each of the tethers 56 and 57 has a strip shape (rectangular plate shape) that is long in the left-right direction.

  The upper tether 56 is located immediately below the knee protection expansion portion 47 and is disposed so as to partition the knee protection expansion portion 47 and the shin protection expansion portion 48. The lower tether 57 is mounted on the vehicle. When the airbag body 40 is completely deployed and inflated, the airbag body 40 is disposed at a position separated from the case 11 toward the vehicle rear side.

  Each gas flow hole 58 is disposed away from the inner peripheral surface 40e of the airbag body 40, and the gas pressure of the inflation gas G in the knee protection inflating portion 47 is substantially equal at each part along the left-right direction. The opening area is adjusted so as to be uniform. In the case of the embodiment, three gas flow holes 58A, 58B, 58C, 58D, 58E, and 58F are disposed in each of the tethers 56 and 57.

In the lower tether 57 that is the upstream side of the inflation gas G from the inflator 26, the side where each gas circulation hole 58D, 58E, 58F is close to the gas discharge port 28a of the inflator 26 in the left-right direction. That is, the side closer to the inflow opening 43 is set as a small opening area, and the opening area is increased as the distance from the inflow opening 43 increases. That is, the gas flow hole 58D which is closest to the inlet opening 43 in the right edge 40d of the airbag body 40, as the smallest opening area, most from the inflow opening 43 in the left edge 40c of the airbag body 40 The gas flow holes 58F that are separated from each other have the largest opening area, and the gas flow holes 58E between the flow holes 58D and 58F have an opening area that is substantially intermediate between the holes 58D and 58F. These opening shapes are formed in an oval shape in which the length in the front-rear direction connecting the occupant side wall portion 41 and the vehicle body side wall portion 42 to each other is long, and the length in the left-right direction is shortened. It is comprised so that the expansion | extension of the front-back direction in the arrangement | positioning site | part may be suppressed. In addition, if the length of the hole 58 is shortened in the front-rear direction and the length in the left-right direction is increased, the hole 58 is easily opened in the front-rear direction, and the tether 57 is easily extended in the front-rear direction at the portion where the flow hole 58 is disposed.

  Further, in the case of the tether 56 directly below the knee protection inflating portion 47, in the case of the embodiment, the gas flow holes 58A, 58B, and 58C have the same opening shape because the gas flow holes 58 in the tether 57 have a large rectifying action. And the gas pressure of each part in the left-right direction in the knee protection expansion part 47 is set so that it may become substantially equal as the same opening area.

  Furthermore, the arrangement positions of these gas circulation holes 58 are arranged at positions that are away from the front side of the interference position with the shin L of the driver M in the airbag main body 40 when the inflation is completed. Therefore, since the left and right shins L of the driver M are arranged substantially along the up-and-down direction, in the case of the embodiment, the gas flow holes 58 between the tether 57 and the tether 56 are defined as positions that are separated from the shins L. The holes 58A are arranged above the hole 58D, the hole 58B is arranged above the hole 58E, and the hole 58C is arranged above the hole 58F.

  Next, the mounting of the knee protection airbag device S of the embodiment on a vehicle will be described. First, when manufacturing the airbag 39, a predetermined cloth material is prepared in a state where the occupant side and the vehicle body side wall portions 41 and 42 are connected to the lower edge 40b side of the airbag body 40, and the air in the cloth material is prepared. The corresponding edges in the front-rear direction of the tethers 56 and 57 are stitched to one of the passenger side and vehicle body side wall portions 41 and 42 on the inner peripheral surface 40e side of the bag body 40, and then the lower edge 40b of the airbag body 40 The other edge in the front-rear direction of each of the tethers 56 and 57 is stitched to the other vehicle body side and the occupant side wall portions 42 and 41 while folding the side in half. Further, the tethers 56 and 57 are folded in the vicinity of the middle in the front-rear direction, and the left and right edges of the tethers 56 and 57 are overlapped, and the outer peripheral edges of the passenger side and the vehicle body side wall portions 41 and 42 are overlapped. Thus, the airbag 39 can be manufactured by sewing the outer peripheral edges of the wall portions 41 and 42 together with the left and right edges of the tethers 56 and 57 together.

  In addition, before sewing the peripheries of the outer peripheral edges of the wall portions 41 and 42, the holding portion 22 is protruded from the insertion hole 44 formed in advance in the prepared cloth material, and the bolt 21 is inserted from the insertion hole 45. The retainer 19 is stored in the airbag body 40 so as to protrude.

  Then, the airbag body 40 is folded together with the tethers 56 and 57. In the folding process of the airbag main body 40, in order to reduce the dimensions in the vertical direction and the horizontal direction so as to be accommodated in the case 11 from a state where the occupant side and the vehicle body side wall portions 41 and 42 are overlapped and flattened, It is folded through a horizontal folding step for folding along the left-right direction and a vertical folding step for folding along the vertical direction, and in the case of the embodiment, in the horizontal folding step, the upper edge folding step and It is folded by performing a roll folding process.

  In the upper edge folding step, as shown in FIGS. 10A and 10B, the airbag body 40 is arranged such that the upper edge 40a side of the airbag body 40 when the inflation is completed approaches the lower edge 40b side when the inflation is completed. The occupant side wall portion 41 and the vehicle body side wall portion 42 on the upper edge 40a side are respectively folded to form the upper edge folding portion 51. Such a folding method in which the occupant side wall portion 41 and the vehicle body side wall portion 42 are individually folded and the edge 40a is inserted into the airbag body 40 is generally referred to as cactus folding.

  Further, in this upper edge folding step, as shown in the XX cross-sectional view, the upper edge 40a is folded by placing the fold line 51a protruding on the lower edge 40b side on the upper edge 40a side against the tether 56 at the upper end. If configured, the length dimension in the vertical direction on the upper edge 40a side folded into the airbag body 40, that is, the length dimension L1 in the vertical direction of the upper edge folding portion 51 can be easily set for each airbag 39. The air bag 39 can be stabilized, and the working efficiency when the airbag 39 is folded can be improved. Incidentally, in the XX cross-sectional view, the tether 56 and the fold 51a of the upper edge folding portion 51 are illustrated with a gap, but actually, the fold 51a is applied to the tether 56 and the tether 56 56 is folded so as to extend by being pushed toward the lower edge 40b. In the case of the embodiment, the length dimension L1 of the upper edge folding portion 51 is about 50 mm.

  Then, in the roll folding process after the upper edge folding process, as shown in FIGS. 10B and 10C, the upper edge 52 side after the upper edge folding process is placed on the side of the vehicle body side wall 42 when the expansion is completed. A roll fold portion 53 is formed by folding the roll so as to approach the lower edge 40b.

  Next, as shown in FIGS. 10C and 10D, as the longitudinal folding process is performed so that the width dimension in the left-right direction is narrowed, the left and right ends 53b of the roll folding portion 53 are folded so as to approach the center 53a. The folding of the main body 40 is completed.

  After the folding of the airbag main body 40 is completed, the airbag main body 40 is wrapped with a wrapping film (not shown) that can be broken to prevent collapse. At this time, the holding portion 22 and the bolt 21 of the retainer 19 protruding from the insertion holes 44 and 45 are protruded from the wrapping film, and the inflow opening 43 in the wrapping film is also opened.

  Subsequently, the folded airbag 39 is moved together with the retainer 19 so that the holding portion 22 and the bolt 21 of the retainer 19 protrude from the insertion hole 15 a and the through hole 15 b formed in the case bottom wall portion 15, respectively. And housed in the case 11. Then, the nut 24 is screwed into the bolt 21 protruding from the through hole 15b.

  Thereafter, the head portion 28 of the inflator 26 is inserted into the guide channel 17 through the insertion hole 17a so as to be inserted into the holding portion 22 from the head portion 28 side, and each pressing piece 22a of the holding portion 22 is inserted. The retainer 19 can be fixed to the case bottom wall 15 and the inflator 26 and the air bag 39 can be fixed to the case 11 by crimping the inflator 26 against the inflator 26 so that the inflator 26 cannot be removed from the holding portion 22. Can be assembled.

  Thereafter, the airbag cover 32 is assembled to the case 11 so that the tip 13a of each locking claw 13 is locked to the periphery of each locking hole 35c. Then, a mounting bracket (not shown) of the case 11 is fixedly attached to the instrument panel reinforcement on the body side, and at the same time, the connector 29 connected to the lead wire 30 is connected to the main body 27 of the inflator 26. Thereafter, if the instrument panel 8 and the under cover 9 (see FIGS. 1, 2, and 4) are attached, the knee protection airbag device S can be mounted on the vehicle.

  After the airbag device S is mounted on the vehicle, if an operation signal is input to the main body 27 of the inflator 26 via the lead wire 30, the inflation gas G is discharged from the gas discharge port 28a formed in the head 28. The inflation gas G flows into the airbag main body 40 through the opening 43 of the airbag main body 40, and the airbag main body 40 pushes the door portion 38 open as shown in FIGS. 11 projecting from the projecting opening 11a to the vehicle rear side, and further expanding and inflating while eliminating the folding in the folding process, thereby completing the expansion.

  In that case, in the knee protection airbag device S of the embodiment, the tethers 56 and 57 below the knee protection inflatable portion 47 of the airbag body 40 have the opening areas of the plurality of gas flow holes 58 adjusted. When the airbag body 40 is deployed and inflated, as shown in FIG. 7, the pressure of the inflation gas G flowing into the knee protection inflating portion 47 through the plurality of gas flow holes 58 is substantially uniform at each portion along the left-right direction. Therefore, even if the knee protection inflating portion 47 interferes with the vicinity of the knee K of the driver M approaching in the middle of the expansion, the knee K is not unnecessarily pressed and the knee K is accurately detected. The neighborhood can be protected.

  In particular, these gas flow holes 58 are not separated from the inner peripheral surface 40e of the airbag main body 40 and are not in contact with the inner peripheral surface 40e of the airbag main body 40. Therefore, the gas pressure can be accurately adjusted by adjusting the opening area. Can be adjusted. Incidentally, if a part of the periphery of the gas circulation hole 58 is constituted by the inner peripheral surface 40e itself of the airbag main body 40, the gas circulation hole 58 is guided by the inner peripheral surface 40e of the airbag main body 40. Therefore, it is difficult to adjust the gas pressure by adjusting the opening area.

  And the tethers 56 and 57 whose opening areas of the plurality of gas flow holes 58 are adjusted are arranged at the positions of the free space separated from the case 11 as the storage portion in the airbag main body 40 when the inflation is completed. Then, the expansion gas G is allowed to flow upward through the gas flow holes 58 in a rectified state without being affected by the expansion gas G that has collided with the inner peripheral surface of the case 11 and changed the flow. Thus, the gas pressure in the knee protection inflatable portion 47 can be made substantially uniform at each portion along the left-right direction for each airbag 39 without causing the gas pressure to vary as much as possible.

  In addition, in the state where the lower portion 48 of the airbag body 40 partitioned by the tether 56 disposed along the left-right direction is inflated widely, the upper portion 47 of the airbag body 40 on the upper side of the tether 56 is Since the airbag body 40 begins to expand, the airbag body 40 is expanded and expanded widely, and is expanded and expanded upward, so that the lower portion 48 side of the airbag body 40 moves forward before the deployment is completed. The shin L and the like below the knee K can be protected with good cushioning properties.

  Therefore, in the airbag device S for knee protection of the embodiment, the gas pressure in the knee protection inflating portion 47 of the airbag 39 in the middle of deployment and inflation can be made substantially uniform at each part along the left-right direction, The vicinity of the knee K of the driver M approaching can be protected accurately.

  In the embodiment, the gas flow hole 58 is disposed at a position away from the front side of the interference position with the shin L of the driver M in the airbag main body 40 when the inflation is completed. Therefore, at the position where the gas flow holes 58 of the tethers 56 and 57 are arranged, the tethers 56 and 57 are easy to extend in the front-rear direction, and the separation distance between the occupant side and the vehicle body side wall parts 41 and 42 as shown in FIGS. If the gas flow hole 58 of the tether 56/57 is disposed at a position away from the position where it interferes with the shin L, it is difficult to avoid increasing the thickness of the airbag body 40 from the other part. Without pressing the shin L unnecessarily, the heel L of the driver M as well as the knee K can be accurately protected by the airbag body 40.

  Note that the position where the gas flow hole 58 is disengaged from the front side of the shin L only needs to be a state in which the shin L is not unnecessarily compressed. It suffices if it is away from the center of the left and right direction protruding to the left and right, so that, for example, in the projection state on the front side of the shin L, a part of the periphery of the gas circulation hole 58 is slightly It may overlap.

  Further, in the embodiment, the tethers 56 and 57 in the airbag main body 40 are arranged in a plurality of stages in the vertical direction, and the rectifying action of the inflation gas G passing through the gas flow holes 58 of the respective tethers 56 and 57 is achieved. As a result, the gas pressure in the knee protection inflating portion 47 of the airbag main body 40 in the middle of deployment and inflation can be made even at each portion along the left-right direction. Furthermore, the thickness of the airbag main body at the time of completion of inflation can be regulated by each part, and it is easy to maintain the overall plate shape of the airbag main body 40 at the time of completion of inflation by eliminating partial swelling.

  Of course, if the above points are not taken into consideration, only one stage of tether may be arranged. In the embodiment, the opening shape and the opening area of the plurality of gas flow holes 58 provided in the upper tether 56 are set to be equal, but the gas pressure of each part along the left-right direction in the knee protection inflating part 47 is equal. Needless to say, the opening area may be adjusted if necessary for the purpose.

  Furthermore, in the airbag 39 of the embodiment, the area from the lower edge 40b side of the airbag body 40 to at least immediately below the knee protection inflating portion 47 at the time of completion of inflation rolls the upper edge 52 side on the vehicle body side wall portion 42 side. It is folded through a roll folding process. Therefore, as in the embodiment, even when the gas flow holes 58 of the tethers 56 and 57 arranged in a plurality of stages in the vertical direction coincide with each other in the vertical direction, the roll fold is unwound when the folding is canceled. The expansion gas G is obstructed by the roll folding portion 53 and it becomes difficult to directly enter the gas flow hole 58 at the upper position, and each portion along the left-right direction in the knee protection expansion portion 47 It does not hinder the action and effect of making the gas pressure substantially equal. Further, the roll folding portion 53 is formed by roll-folding the upper edge 52 side on the side of the vehicle body side wall 42, and when the folding is canceled and the vehicle is expanded upward, Even if the interval is narrow, the protrusion to the driver M side is suppressed, and it is easy to approach the vehicle body 6 side and complete the deployment.

  Furthermore, in the case of the embodiment, before the roll folding step, the knee protection inflatable portion 47 is folded into the airbag body 40 so that the upper edge 40a side approaches the lower edge 40b side of the airbag body 40. The airbag body 40 is folded by providing an upper edge folding process. Therefore, the occupant side wall portion 41 and the vehicle body side wall portion 42 in the vicinity of the upper edge 40a of the airbag body 40 are merely folded in the front-rear direction of the vehicle. When pushed, the upper edge 40a easily protrudes upward, and the folding is quickly eliminated. In addition, even if the occupant side wall 41 and the vehicle body side wall portion 42 around the upper edge 40a folded into the airbag body 40 are in contact with the knee K or the vehicle body 6 and the frictional resistance is large, The upper edge 40a of the airbag main body 40 that is not in direct contact with the vicinity of the knees K or the vehicle body 6 easily and quickly protrudes upward. For this reason, if the area 47 on the upper edge 40a side during deployment of the airbag body 40 that interferes with the vicinity of the knee K in the airbag body 40 is folded into the airbag body 40, the area around the knee K of the driver M is the knee. Even when the protective airbag device S is very close, the upper edge 40a side of the airbag body 40 easily enters the narrow gap between the vicinity of the knee K and the vehicle body 6 due to the inflow of the inflation gas G. Thus, the deployment is completed, and further, the expansion of the expansion gas G allows the expansion to be thick, and the vicinity of the knee K can be protected accurately.

  In the case where the side folding process of the airbag 39 is performed only by the roll folding process without performing the upper edge folding process, as shown in parentheses in FIG. If the air bag body 40 interferes with the vicinity of the knee K of the driver M, who is extremely approaching, in such a state that the air bag body 40 is not completely eliminated, the air bag body 40 is connected to the upper edge 40a of the air bag body 40 at the rear side of the vehicle. The downstream portion 40g of the inflation gas G is inflated. Between the vicinity of the knee K and the vehicle body 6, an upper edge 40a of the airbag body 40 and a downstream portion 40g of the inflation gas G connected to the upper edge 40a are provided. Further, if the upper edge 40a of the airbag body 40 does not come out between the vehicle body 6 and the downstream portion 40g due to friction or the like, the operation is performed by the expansion of the downstream portion 40g and the expansion of the upper edge 40a itself. Site of the air bag body 40 that is interfering with the near knee K of M is, bulging thick, which could lead to a situation to press the vicinity of the knee K of the driver M to the rear of the vehicle, which is not preferable.

  In addition, in the embodiment, the airbag main body 40 causes the inflation gas G to flow in a biased manner from one right edge 40d side in the left-right direction on the lower edge 40b side of the airbag main body 40 when the inflation is completed. Although configured, the gas flow holes 58D, 58E, and 58F of the tether 57 reduce the opening area on the side close to the inflow position of the expansion gas G and increase the side away from the inflow position of the expansion gas G. Thus, it is adjusted and arranged.

  In such a configuration, as in the embodiment, the cylinder-type inflator 26 in which the gas discharge port 28a is disposed on the end side with respect to the case 11 serving as a storage portion for storing the airbag 39 is arranged in the axial direction. Can be applied to the knee protection airbag device S configured to be held along the left-right direction of the case 11. That is, in the knee protection airbag device S as in the embodiment, even if the inflator 26 is provided outside the case 11 or in the airbag body 40, the inflation flows from the axial end side of the inflator 26. The working gas G flows in a biased manner from the right edge 40d side in the left-right direction on the lower edge 40b side of the airbag body 40 when the inflation is completed. Even in this case, the airbag body in the middle of deployment and inflation The gas pressure in the 40 knee protection inflating portions 47 can be made substantially equal in each part along the left-right direction, and the vicinity of the knee K of the driver M approaching can be protected accurately. .

  In such a knee protection airbag device S, since the inflator 26 can be disposed within the lateral width of the case 11 using the cylinder-type inflator 26, The size can be reduced and the apparatus can be made compact.

  Moreover, in the airbag apparatus S for knee protection of embodiment, the passenger | crew side and vehicle body side wall parts 41 and 42 can mutually be maintained in the airbag main body 40 so that the airbag main body 40 at the time of completion of expansion | deployment can be maintained in a substantially plate shape. A plurality of tethers 56 and 57 for regulating thickness to be connected are arranged side by side in the vertical direction, and are respectively arranged along the left and right direction. The fold 51a of the folding part 51 is applied to the tether 56 at the upper end, and the upper edge 40a side is folded. Therefore, the vertical dimension L1 of the upper edge folding part 51 formed in the upper edge folding process can be easily stabilized for each airbag 39, and the working efficiency when folding the airbag 39 is improved. can do.

  In the embodiment, the vertical folding process for narrowing the width dimension in the left-right direction is performed after the horizontal folding process so that it can be stored in the case 11 as a storage part, but the vertical folding process is performed before the horizontal folding process, Alternatively, it may be performed between the upper edge folding process and the roll folding process, and if the width dimension of the case 11 in the left-right direction is large, the vertical folding process need not be performed.

  In the knee protection airbag device S of the embodiment, the guide flow path that covers the head 28 of the inflator 26 and guides the inflation gas G from the gas discharge port 28 a to the inflow opening 43 of the airbag body 40. 17 is provided in the case 11, but the guide channel 17 covering the head 28 is provided so that the retainer 19 is inserted through the insertion hole 15 c of the bottom wall portion 15 and the airbag opening 43. Also good.

  Furthermore, in the airbag apparatus S for knee protection of the embodiment, the inflator 26 is disposed outside the case 11, and the airbag body 40 is not stored in the airbag body 40 without requiring the handling of the inflator 26 to be handled with care. Therefore, the folding of the airbag main body 40 can be easily automated. Of course, if this point is not considered, the inflator 26 is accommodated in the airbag main body 40 and the airbag main body 40 is folded, as described in the technical document 1, etc. In addition, the airbag body 40 may be configured to be housed in the case 11.

  Furthermore, in the embodiment, the knee protecting airbag device S for the driver M is illustrated, but the knee protecting airbag device of the present invention may be mounted on the front side of the passenger seat.

It is a schematic longitudinal cross-sectional view of the vehicle front-back direction which shows the use condition of the airbag apparatus for knee protection which is one Embodiment of this invention. FIG. 4 is a schematic enlarged longitudinal sectional view of the knee protection airbag device in the vehicle front-rear direction, showing a II-II portion of FIG. 3. It is a schematic cross-sectional view of the III-III part of FIG. It is the schematic front view seen from the vehicle back side which shows the use condition of the airbag apparatus for knee protection of embodiment. It is a front view of the airbag used in an embodiment. It is the longitudinal cross-sectional view which expanded the airbag which accommodated the retainer independently, and respond | corresponds to the VI-VI site | part of FIG. It is the longitudinal cross-sectional view which expanded the airbag alone, and respond | corresponds to the VII-VII site | part of FIG. It is a cross-sectional view of the inflated air bag alone, corresponding to VIII-VIII site of FIG. Is a cross-sectional view of the inflated air bag alone, it corresponds to the IX-IX site of FIG. It is a figure explaining the folding process of the airbag of an embodiment. It is a schematic longitudinal cross-sectional view which shows the state at the time of the action | operation of the airbag apparatus for knee protection of embodiment. It is a schematic longitudinal cross-sectional view which shows the state at the time of the completion | finish of operation | movement of the airbag apparatus for knee protection of embodiment.

Explanation of symbols

11 ... (storage part) case,
39 ... Airbag,
40 ... Airbag body,
40a ... upper edge,
40b ... lower edge,
40e ... inner peripheral surface,
41 ... the passenger side wall,
42 ... side wall of vehicle body,
47 ... Knee protection inflatable part,
48 ... shin protection expansion part,
56, 57 ... tether,
58 (58A, 58B, 58C, 58D, 58E, 58F) ... gas flow hole,
G ... expansion gas,
K (KL / KR) ... Knee,
L ... Shin,
M ... Crew,
S: Air bag device for knee protection.

Claims (5)

In order to protect the occupant's knees, as a configuration that allows inflation gas to flow in, protrudes from the storage site to the vehicle rear side, and expands and expands upward,
An airbag body having an occupant side wall portion located on the occupant side at the time of completion of inflation, and a vehicle body side wall portion located on the vehicle body side;
A tether that connects the occupant side wall and the vehicle body side wall to regulate the thickness of the airbag body when the inflation is completed;
An airbag comprising:
A knee protection airbag device comprising:
The airbag main body is configured to dispose a knee protection inflatable portion on the upper edge side when inflation is completed,
The tether is positioned along the left-right direction so as to divide the inside of the airbag body vertically below the knee protection inflating portion at a position separated from the storage site in the airbag body when the inflation is completed. It is connected to the entire area of the inner peripheral surface of the airbag body, and has a plurality of gas circulation holes, and is arranged,
As the position where the plurality of gas circulation holes are separated from the inner peripheral surface of the airbag main body and are removed along the left-right direction from the front side of the interference position with the occupant's shin in the airbag main body when the inflation is completed, A knee protection airbag device comprising gas circulation holes respectively disposed on a left edge side and a right edge side of an airbag body . A plurality of the gas flow holes are disposed between the two gas flow holes respectively disposed on the left edge side and the right edge side of the airbag body as positions where the gas flow holes are disengaged from the front side of the interference position with the occupant's shin. The knee protection airbag device according to claim 1, wherein the knee protection airbag device is configured to include a gas circulation hole . The knee protection airbag device according to claim 1 , wherein the tether is arranged in a plurality of stages in the vertical direction. The opening area of the gas flow hole that is farthest from the inflow position of the expansion gas in the tether is set larger than the opening area of the gas flow hole that is closest to the inflow position of the expansion gas. The knee protection airbag device according to any one of claims 1 to 3, wherein the knee protection airbag device is provided. The airbag body is configured to flow inflatedly from one edge side in the left-right direction on the lower edge side of the airbag body when inflation is completed,
The plurality of gas flow holes in the tether located at least at the lowermost end have an opening area that is smaller on the side close to the inflow position of the expansion gas and larger on the side away from the inflow position of the expansion gas. The knee protection airbag device according to any one of claims 1 to 4, wherein the knee protection airbag device is adjusted and disposed.

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