JP2005206068A - Knee protection airbag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag capable of preventing interference with a key accessory so as to be damaged during the deployment and inflation, and correctly protecting knees of a driver. <P>SOLUTION: A knee protection airbag 40 is folded and stored below a steering column 2 on the forward side of a driver and on the lower side of a key cylinder 6 in which a key E with an accessory A hanging therefrom can be inserted, and deployed and inflated so as to protect knees of a driver when inflation gas flows in. The airbag 40 comprises a cover part 47 to cover a rear side of a vehicle in an area in a vicinity of a key cylinder 6 on an upper edge 40a side when deployment and inflation are completed, and a general part 46. The cover part 47 is constituted by sewing a column side wall part 42 and a driver side wall part 41 by a breakable sewing thread 50, and starting to inflate around the time of completion of inflation of the general part 47 by breaking the sewing thread 50. A sewn part 48 by the sewing thread 50 is arranged around an outer edge 48a of the cover part 47 and an inner side 48b thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a knee protecting airbag that can be deployed and inflated to protect a driver's knee.

Conventionally, an airbag of a knee protecting airbag device that protects a driver's knee has been folded and housed in a case disposed on the front side of the driver. When the inflation gas flows in, the airbag rises along the lower surface of the steering column and completes the deployment and inflation to protect the driver's knee. Furthermore, the airbag is provided with an inflated portion that covers the rear side of the vehicle in the region near the key cylinder when the inflating and inflating is completed, in the vicinity of the corner in the left-right direction on the upper edge side (see, for example, Patent Document 1).
International Publication No. 02/04261 Pamphlet

  However, at the place where the conventional knee protection airbag device is mounted, key accessories such as various subkeys and accessories may be suspended from the key inserted into the key cylinder. In that case, when the inflated portion of the airbag that is inflated and inflated comes into contact with the lower end side of the key accessory, in particular, when the lower end side of the key accessory comes in contact with the inflated portion in the orthogonal direction, the gas There is a risk of damaging the airbag so as to cause a leak.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object thereof is to provide an airbag that can prevent interference with a key accessory so as to be damaged when deployed and inflated, and can accurately protect a driver's knee. To do.

The airbag for knee protection according to the present invention is folded and stored below the steering column on the front side of the driver, and below the key cylinder into which a key with suspended accessories can be inserted,
A knee protecting airbag that protects the driver's knee by completing deployment and inflating while projecting from the storage part to the vehicle rear side while inflating gas flows,
While having a substantially plate shape including a column side wall portion located on the steering column side upon completion of expansion and expansion, and a driver side wall portion located on the driver side,
A cover portion that is disposed in the vicinity of the left and right corners on the upper edge side at the time of completion of expansion and expansion and covers the rear side of the vehicle in the vicinity of the key cylinder, and a general portion,
The cover is
The column side wall portion and the driver side wall portion are sewn with a breakable suture, and the suture portion is configured to start to expand from the vicinity of the expansion completion time of the general portion by the suture breakage. Is arranged in the vicinity of the outer edge of the cover portion and inside thereof.

  In the knee protection airbag according to the present invention, when inflating gas is introduced in a vehicle-mounted state, the general portion completes inflating while protruding from the storage portion to the vehicle rear side and rising, and the suture thread And the cover part begins to expand from the vicinity of the expansion completion time of the general part, thereby completing the expansion and expansion.

  At that time, even if key accessories such as subkeys and accessories are suspended from the key inserted into the key cylinder, the cover part that interferes with the key accessories reduces the inflow amount of the inflation gas at the beginning of placement, Because it is a thin plate, even if it interferes with the lower end side of the key accessory, it will not interfere so that it will be scratched, and conversely, deployment will be completed with the key accessory being flipped, and then gas leakage will occur. The suture can be ruptured and expanded thickly without causing any damage. In particular, in the cover part of the present invention, since the sutured portions by the suture are arranged near the outer edge of the cover part and the inside thereof, the development can be completed as a thin plate without fail.

  Note that if the cover part is not a thin plate, but is thickly expanded and interferes with the lower end of the key accessory in an orthogonal state, the key accessory may be damaged and gas leakage may occur. Will occur.

  Therefore, in the knee protection airbag according to the present invention, it is possible to prevent interference with the key accessory so as to be damaged during deployment and protect the driver's knee accurately.

  Further, in the knee protection airbag according to the present invention, it is possible to prevent damage from the key accessory by simply sewing the column side wall portion and the driver side wall portion of the cover portion with a breakable suture. It can be easily manufactured using conventional products.

  And it is desirable to form the stitching line of the stitching site in a one-stroke shape using continuous sutures.

  In such a configuration, when the cover part is inflated, if a part of the suture in the suture line is broken and the column side wall part and the driver side wall are separated, the separation is caused by the breakage or disconnection of the suture thread. It is easy to propagate to the entire length of the stitching line, the cover part can be rapidly expanded, and the knee can be accurately protected also by the area of the cover part that has completed the expansion.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A knee protection airbag device S in which the knee protection airbag 40 of the embodiment is used is shown in FIGS. The vehicle is disposed below the steering column 2 on the front side of the vehicle of the driver D so that the knee K can be protected.

  The vertical / front / rear / left / right relationship in this specification is based on the state in which the airbag device S is mounted on the vehicle, and is consistent with the vertical / front / rear / left / right relationship of the vehicle when mounted. It is.

  As shown in FIG. 1, the steering column 2 includes a main shaft 3 coupled to the steering wheel 1, a column tube 4 covering the periphery of the main shaft 3, and a column cover 5 covering the periphery thereof. Has been.

  The column cover 5 is made of a synthetic resin having a substantially rectangular tube shape or the like, and is disposed along the axial direction of the main shaft 3 so as to cover the main shaft 3 and the column tube 4 below the steering wheel 1. The column cover 5 is disposed so as to protrude obliquely upward and rearward from an instrument panel (hereinafter referred to as instrument panel) 10. A key cylinder 6 for inserting an ignition key E for starting the engine is disposed on the right side surface 5c of the column cover 5. In the case of the embodiment, an accessory (key accessory) A such as a sub key is suspended from the ignition key E inserted into the key cylinder 6 by using a connection tool J such as a connection ring. It is connected.

  The knee protection airbag device S stores the folded airbag 40, the inflator 21 that supplies inflation gas to the airbag 40, the folded airbag 40 and the inflator 21, and opens the vehicle rear side. A case 13 and an airbag cover 29 that covers the vehicle rear side of the case 13 are provided.

  As shown in FIGS. 1 to 3, the case 13 is made of sheet metal and is arranged on the lower side of the steering column 2. The case 13 has a substantially square cylindrical peripheral wall portion 14 and a bottom wall that closes the vehicle front side of the peripheral wall portion 14. And a substantially rectangular opening 13a on the vehicle rear side. A plurality of locking portions 15 for assembling the side wall portions 31 and 32 of the airbag cover 29 to the case 13 are respectively provided on the outer surface sides of the wall portions 14 a and 14 b facing the top and bottom of the peripheral wall portion 14 of the case 13. (15U · 15D) are provided.

  The locking portion 15U disposed on the outer surface side of the upper wall portion 14a can be inserted into the locking hole 31a of the upper side wall portion 31 of the airbag cover 29 to lock the periphery of the locking hole 31a. It is configured as a locking hook. A plurality of locking hooks 15 </ b> U are arranged along the left-right direction of the vehicle corresponding to the locking holes 31 a of the upper side wall portion 31. The locking portion 15D is configured as a locking projection that can be inserted into the locking hole 32a of the lower wall portion 32 of the airbag cover 29. The locking projection 15D also corresponds to the locking hole 32a of the lower wall portion 32. A plurality of vehicles are arranged along the left-right direction of the vehicle. Then, a hook 16 is inserted into each locking projection 15D to prevent the locking projection 15D from coming off from the locking hole 32a after being inserted into the locking hole 32a. The saddle member 16 is fixed to the case 13 by inserting the insertion portion 16a between the outer surface of the lower side wall portion 32 and the inner peripheral surface of each locking projection 15D.

  Furthermore, the through-hole 14d which can penetrate the edge part of the main body 22 of the inflator 21 is formed in the wall part 14c of the right side in the surrounding wall part 14 (refer FIG. 3). The bottom wall portion 17 is formed with two insertion holes 17a through which the bolts 23d of the inflator 21 are inserted.

  The case 13 includes a flange portion 19 that extends outward from the peripheral wall portion 14 around the opening 13a. The case 13 is fixed to the body side of the vehicle by projecting brackets (not shown) from predetermined portions of the flange portion 19, the peripheral wall portion 14, and the bottom wall portion 17.

  As shown in FIGS. 2 and 3, the inflator 21 is configured as a cylinder type in which the axial direction is disposed along the left-right direction of the vehicle, and includes a substantially cylindrical main body 22 and a diffuser 23. The main body 22 includes a substantially cylindrical general portion 22a and a small-diameter small-diameter portion 22b protruding from the end surface of the general portion 22a, and a plurality of gas discharge ports 22c are disposed on the outer peripheral surface of the small-diameter portion 22b. It is configured. And the connector 26 which connected the lead wire 27 for an operation signal input to the end surface apart from the small diameter part 22b in the general part 22a is connected.

  The diffuser 23 has a substantially cylindrical shape that can cover the main body 22, and a plurality of gas outlets 23 a through which the expansion gas can flow out are disposed on the rear surface of the vehicle mounted state. The diffuser 23 includes a plurality (two in the embodiment) of bolts 23d that protrude toward the front side of the vehicle. Further, the diffuser 23 includes a plurality of clamping portions 23 c for holding the main body 22. The main body 22 is fixed to the diffuser 23 by inserting the main body 22 into the diffuser 23 from the insertion hole 23b with the small-diameter portion 22b at the head, and further pressing each clamping portion 23c toward the outer peripheral surface of the general portion 22a. Then, the main body 22 can be fixed to the diffuser 23, and each bolt 23 d is inserted into the insertion hole 17 a of the bottom wall portion 17 of the case 13 and the nut 24 is tightened to fix the inflator 21 to the case 13. be able to.

  The inflator 21 receives an operation signal via the lead wire 27 when the airbag operation circuit mounted on the vehicle detects a frontal collision of the vehicle. At the same time, the inflator 21 is mounted on the steering wheel 1. An airbag device (not shown) is also activated.

  The airbag cover 29 is configured to be able to cover the vehicle rear side in the vicinity of the opening 13 a of the case 13 and in the vicinity of the flange portion 19, and is connected and held to the case 13. As shown in FIGS. 1 and 8, the airbag cover 29 is disposed on the side of the lower panel 10b on the peripheral edge of the column cover 5 in the instrument panel 10 composed of the upper panel 10a and the lower panel 10b, and protrudes from the instrument panel 10. Covers the lower edge.

  The airbag cover 29 is disposed around the door portions 37 and 38 that cover the opening 13a of the case 13 on the vehicle rear side, as shown in FIGS. And a general portion 30 that is surrounded by the lower panel 10b when mounted on the vehicle. The airbag cover 29 is formed of a portion including the door portions 37 and 38 and the side wall portions 31, 32, 33, and 34 from a thermoplastic elastomer such as polyolefin, and the surrounding general portion 30 is made of polypropylene or the like. It is a two-color molded product formed from a synthetic resin.

  The door portions 37 and 38 are formed in a substantially rectangular plate shape, and are configured by disposing a thin portion to be broken 36 having a substantially H shape around the door portions 37 and 38. The planned break portion 36 has a continuous or intermittent groove on the front surface of the airbag cover 29 so that the door portions 37 and 38 are easily broken when pushed by the inflating airbag 40. Provided and formed. When the planned breakage portion 36 is pushed by the airbag 40 and breaks, the door portion 37 opens upward with the upper wall portion 31 and the vicinity of the upper end side as a hinge portion, and the door portion 38 opens on the lower end side. The vicinity of the lower side wall portion 32 is opened as a hinge portion by opening downward.

  In addition, at the portion around the door portions 37 and 38, four side wall portions 31, 32, 33, and 34 that protrude toward the vehicle front side so as to be adjacent to the peripheral wall portion 14 on the outer peripheral side of the peripheral wall portion 14 of the case 13. Is formed. And the upper side wall part 31 arrange | positioned at the upper part side of the case surrounding wall part 14 and the lower side wall part 32 arrange | positioned at the lower part side of the surrounding wall part 14 become a site | part which connects and holds the airbag cover 29 to the case 13, These As described above, each of the locking portions 15 (15U, 15D) disposed on the peripheral wall portion 14 is inserted into each of the wall portions 31 and 32, and the peripheral portions of the locking portions 15 are locked. Locking holes 31a and 32a are respectively formed.

  And the airbag 40 of embodiment is formed from the woven fabric which consists of polyester, polyamide yarn, etc. which have flexibility, and the shape at the time of completion | finish of expansion | deployment is shown to FIG. The left and right width dimensions that can protect both knees K of the driver D are substantially rectangular plates. Further, the airbag 40 is configured so that the driver side wall portion 41 is disposed on the driver D side and the column side wall portion 42 is disposed on the column cover 5 side when deployment and inflation are completed. The walls 41 and 42 are formed in substantially the same shape. In the airbag 40 of the embodiment, a single woven fabric in which the walls 41 and 42 are connected to each other on the lower edge (lower end) 40b side is folded in two at the lower edge 40b, and a suture 49 is used. It is formed by stitching the outer peripheral edges together.

  Further, as shown in FIGS. 3 and 7, two insertion holes 43a and 43a and one insertion hole 43b are formed in the portion 43 of the column side wall portion 42 on the lower edge 40b side of the airbag 40. The insertion holes 43 a and 43 a are for inserting the bolts 23 d of the inflator 21, and the insertion hole 43 b is for inserting the main body 22 of the inflator 21. The airbag 40 is attached to the case 13 by causing the main body 22 of the inflator 21 to protrude from the insertion hole 43 b and sandwiching the peripheral edge 43 of each insertion hole 43 a between the diffuser 23 and the bottom wall portion 17 of the case 13. It has been. That is, the airbag 40 is attached and fixed to the bottom wall portion 17 of the case 13 with the peripheral edge of the insertion hole 43 a as the attachment portion 43.

  Further, in the airbag 40, tethers 44 and 45 arranged along the left-right direction are arranged in two upper and lower stages. The tethers 44 and 45 are arranged so that the wall portions 41 and 42 can be connected to maintain the airbag 40 in a plate shape when the inflation is completed. Each of the tethers 44 and 45 is formed of two cloth materials 44a and 45a, respectively.

  Further, in the airbag 40, a cover that covers the rear side of the vehicle in a region near the key cylinder 6 as a substantially rectangular parallelepiped shape that is disposed in the vicinity of the right corner C in the left-right direction on the upper edge side as an inflated portion when the deployment and inflation is completed. A part 47 and a general part 46 excluding the cover part 47 are provided. The cover portion 47 is configured to cover the region of the accessory A hanging from the key E inserted into the key cylinder 6 from the vehicle rear side when the expansion and expansion are completed.

  As shown in FIGS. 4, 6, 8, B 9, the cover 47 is formed by sewing the driver side wall 41 and the column side wall 42 with the breakable suture 50, and breaking the suture 50. The general portion 46 is configured to start expanding from the vicinity of the expansion completion time. As shown in FIG. 4, the suture part 48 by the suture thread 50 includes a U-shaped part 48 a along the vicinity of the outer edge of the cover portion 47, and a U-shaped part 48 b inside thereof. Has been. Further, in the airbag 40, the outer edge portion 48a and the inner portion 48b are connected by the connecting portion 48c, and the stitching line of the stitching portion 48 is formed in a one-stroke J-shape using the continuous suture 50. Has been.

  The breaking strength of the suture thread 50 is lower than the breaking strength of the suture thread 49 so that the suture thread 50 can be broken, and the internal pressure of the airbag 40 has increased to a predetermined value or more after the general portion 46 has been inflated. At this time, the setting is made so that the suture thread 50 at the suture site 48 can be broken and the cover portion 47 can be rapidly expanded.

  The airbag 40 is manufactured by using a suture 49 before folding one sheet material for the airbag 40 provided with the insertion holes 43a and 43b at a portion on the lower edge 40b side of the airbag 40. Then, the cloth materials 44a and 45a are stitched at predetermined positions of the sheet material, and the cloth material 44a and the cloth material 45a are stitched together and folded in two at the lower edge 40b. The airbag 40 can be manufactured by sewing the outer peripheral edges of the person side wall portion 41 and the column side wall portion 42 with the suture thread 49 and further forming the suture portion 48 using the suture thread 50. By the way, the outer peripheral edges of the wall portions 41 and 42 are sewn together so that the inflator 21 can be inserted and a part thereof is left without being sewn, and after the inflator 21 is inserted, the unsewn portion is sewn.

  Next, assembly of the airbag device S will be described. First, the assembled inflator 21 is housed in the airbag 40 so that the bolts 23d protrude from the insertion holes 43a and the end portions of the main body 22 protrude from the insertion holes 43b. Subsequently, the unstitched portions left between the outer peripheral edges of the wall portions 41 and 42 are stitched, and the airbag 40 is folded so as to be housed in the case 13.

  The folding of the airbag 40 is performed by a horizontal folding process in which a lateral fold is made and a vertical folding process in which a lateral width of the airbag 40 is adjusted by attaching a fold in the front-rear direction (vertical direction). Is doing. And in the case of embodiment, after performing a horizontal folding process, the vertical folding process is performed and the airbag 40 is folded. That is, as shown in FIG. 7A, the column side wall portion 42 and the driver side wall portion 41 are overlapped and flattened. First, in the side folding process, as shown in FIGS. The upper edge 40a side of the airbag 40 is wound on the side of the column side wall 42 so as to be folded in the direction, and is folded by roll folding approaching the lower edge 40b side. Next, in the vertical folding process, the left and right end portions 52b and 52b of the folded folded portion 52 are folded as shown in FIGS. It folds so that it may arrange | position below the center part 52a of the site | part 52. FIG.

  Then, after the folding process is completed, the airbag 40 is wrapped with a wrapping film (not shown) that can be broken to prevent collapse. At this time, the bolt 23d of the inflator 21 and the end of the main body 22 protruding from the insertion holes 43a and 43b are protruded from the wrapping film. In addition, as a wrapping film, you may utilize cloth materials, tape materials, and string materials, such as the woven fabric which formed the airbag 40 other than a resin-made sheet material.

  Thereafter, each bolt 23d of the inflator 21 is protruded from the insertion hole 17a, and the end portion of the inflator body 22 is protruded from the insertion hole 14d, so that the inflator 21 is folded into the case 13 together with the folded airbag 40. By storing and fastening a spring nut (not shown) to each bolt 23d, the inflator 21 and the airbag 40 can be stored in the case 13 and attached to the case 13.

  Next, the airbag cover 29 is assembled to the case 13. The air bag cover 29 is assembled to the case 13 by attaching the side wall portions 31, 32, 33, and 34 of the air bag cover 29 to the case peripheral wall portion 14 on the opening 13a side. The locking projections 15D are inserted into the locking holes 31a of the side wall portion 31 and inserted into the locking holes 32a of the lower side wall portion 32 so as to protrude to the outer surface side of the lower side wall portion 32. Between the outer surface of the side wall portion 32 and the inner peripheral surface of each locking projection 15D, the insertion portion 16a of the saddle member 16 is inserted, the bolt 23d is passed through the saddle member 16, and the nut 24 is fastened to the bolt 23d. Then, the airbag cover 29 can be connected and held to the case 13, and the airbag device S can be assembled.

  For mounting the airbag device S on the vehicle, the connector 26 connected to the lead wire 27 is connected to the main body 22 of the inflator 21 and a predetermined bracket extending from the case 13 is connected and fixed to the vehicle body side. At the same time, if the lead wire 27 is connected to the airbag operation circuit, the airbag device S can be mounted on the vehicle.

  At this time, the upper panel 10a, the lower panel 10b, and the like are already attached to the vehicle. The under cover 11 may be attached after the airbag device S is mounted on the vehicle.

  After the air bag device S is mounted on the vehicle, if an operation signal is input to the main body 22 of the inflator 21 via the lead wire 27, the inflation gas is discharged from the gas discharge port 22c of the inflator 21, and the inflation gas is discharged. Then, the air flows into the airbag 40 through the gas outlet 23a of the diffuser 23. The airbag 40 expands to break a wrapping film (not shown) and pushes the door portions 37 and 38 of the airbag cover 29 to break the planned break portion 36. Then, the airbag 40 opens the door portions 37 and 38, and projects toward the vehicle rear side from the opening 13a of the case 13 as a storage portion, as shown by a two-dot chain line in FIG. It expands and expands so as to largely protrude upward along the column cover lower surface 5a.

  In the embodiment, when the airbag 40 flows in the inflation gas and protrudes from the case 13, the airbag 40 is unfolded and expanded and inflated in a substantially reverse process of the folding process of the airbag 40. Therefore, as shown in FIGS. 8A and 8B, the airbag 40 that is inflated and inflated raises the end portions 52b and 52b of the folding portion 52 and eliminates the folding of the roll fold, while The edge 40a side is raised along the lower surface (rear surface) 5a of the column cover 5 to the vicinity of the upper end 5b of the column cover 5 to expand and expand.

  At this time, in the airbag 40, the general part 46 completes the expansion, breaks the suture 50, and the cover part 47 starts to expand from the vicinity of the completion of the expansion of the general part 46 to complete the deployment and inflation. Become.

  At this time, even if the key accessory A such as a sub key or an accessory is suspended from the key E inserted into the key cylinder 6, the cover portion 47 that interferes with the key accessory A is shown in FIG. Since the inflow amount of the expansion gas is reduced at the beginning of the arrangement and is formed into a thin plate shape, even if it interferes with the lower end Ab side of the key accessory A, it does not interfere so as to be damaged. In such a state, the deployment is completed, and then the suture thread 50 can be broken and expanded thickly without causing gas leakage. In particular, in the cover portion 47, the suture portion 48 by the suture thread 50 is configured to include an outer edge portion 48 a near the outer edge of the cover portion 47 and an inner portion 48 b thereof. Deployment can be completed as a thin plate.

  Therefore, in the knee protection airbag 40 of the embodiment, it is possible to prevent the knee accessory K from being interfered with the key accessory A so as to be damaged during deployment and to protect the knee K of the driver D accurately.

  In the knee protection airbag 40 according to the embodiment, the column accessory 42 and the driver sidewall 41 of the cover 47 are simply sutured with the breakable suture 50, and the key accessory A is damaged. Therefore, it can be easily manufactured using a conventional product. In particular, in the airbag 40 of the embodiment, the outer peripheral edges of the wall portions 41 and 42 are also sewn using the sutures 49, and can be easily performed by the sewing operation using the two types of sutures 49 and 50. Can be manufactured.

  Furthermore, in the airbag 40, the expansion of the general portion 46 is completed quickly because there is no volume of the cover portion 47. And, in particular, if the general portion 46 completes the inflation, the airbag 40 is arranged until a portion 40aa on the upper end 40a side excluding at least the cover portion 47 is located near the arrangement position when the inflation is completed. As shown by the two-dot chain line in FIG. 1 and FIG. 8B, the entire airbag 40 can be disposed on the front side of the knee K before the knee K of the driver D greatly advances. . Further, the knee K of the driver D can be accurately protected by the general portion 46 that has already been inflated and the cover portion 47 that is inflated thereafter.

  Therefore, in the airbag 40 of the embodiment, even if the forward speed of the knee K of the driver D is high, the airbag 40 is easily inserted between the knee K of the driver D and the column cover 5 and the lower panel 10b. 40 can be disposed, and the knee K of the driver D can be protected accurately.

  In the case of the embodiment, the general portion 46 that completes the inflation before the cover portion 47 of the airbag 40 is located on both the left and right sides of the tethers 44 and 45 from the vicinity of the lower end 40b of the airbag 40 when the inflation is completed to the vicinity of the upper end 40a. It comprises the part 46a * 46b (refer B of FIG.4, 8) extended substantially linearly. Therefore, the inflation gas G discharged from the inflator 21 smoothly flows from the lower end 40b side to the upper end 40a side of the airbag 40 using the straight portions 46a and 46b of the general portion 46. The arrangement of the upper end 40a side of the 40 is performed quickly, and the entire airbag 40 can be further arranged on the front side of the knee K before the knee K of the driver D greatly advances. .

  Furthermore, in the airbag 40 of the embodiment, the stitching line of the stitching portion 48 of the cover portion 47 is formed in a single stroke using a continuous suture 50. Therefore, when the cover part 47 after the expansion of the general part 46 is expanded, if a part of the suture thread 50 in the sewing line is broken and the column side wall part 42 and the driver side wall 51 are separated, the suture thread The separation or breakage of 50 is easily propagated to the entire length of the stitching line, and the cover 47 can be rapidly expanded, and the knee K can be accurately positioned by the region of the cover 47 that has completed the expansion. Can be protected.

  If this point is not taken into account, as shown in the knee protection airbag 40A shown in FIG. 10, a U-shaped outer edge portion 48a along the vicinity of the outer edge of the cover portion 47 is used as a stitched portion 48A provided in the cover portion 47. And a U-shaped inner part 48b on the inner side thereof, and these parts 48a and 48b may not be connected to each other.

  Further, regarding the stitched portion 48 of the cover portion 47, the portion 48 b inside the outer edge portion 48 a near the outer edge of the cover portion 47 is an area inside the outer edge portion 48 a, and the walls 41 and 42 are stitched by the suture thread 50. In addition to the U-shape as in the embodiment, it may be a V-shape, a simple I-shape, a single-letter shape, or a dot shape. Of course, a plurality of rows such as a double shape or a triple shape may be arranged with the U-shape, V-shape, I-shape, etc. inward.

  Further, the outer edge portion 48a in the vicinity of the outer edge of the cover portion 47 needs to be able to maintain the cover portion 47 in a plate shape together with the inner portion 48b before the suture 50 is broken, that is, before the cover portion 47 is expanded. In the vicinity of the outer edge of the cover part 47, a linearly sewn part parallel to each other is provided in the vicinity of the left and right edges of the cover part 47, or in the vicinity of the lower edge of the cover part 47, for example. A single straight or curved suture site may be provided and configured. However, in order to maintain the entire region of the cover portion 47 in a plate shape, the outer edge portion 48a is formed on the outer peripheral edge of the upper edge 40a and the right edge 40d of the airbag 40, like the stitched portion 48a of the airbag 40 / 40A. It is desirable that the outer edge of the cover portion 47 be continuously disposed along with a part.

  In the embodiment, the case where the key cylinder 6 is arranged on the right side surface 5c of the steering column 2 (column cover 5) itself has been described. However, the key cylinder 6 is arranged on the left side surface of the column 2 or the column cover. Even when it is arranged at a position away from 5, it is possible to apply the present invention by providing the airbag with a cover portion that interferes with the accessory A of the key E inserted into the key cylinder 6.

It is a schematic longitudinal cross-sectional view of the vehicle front-back direction which shows the use condition of the airbag apparatus using the knee protection airbag which is one Embodiment of this invention. It is a general | schematic expanded longitudinal cross-sectional view of the vehicle front-back direction of the airbag apparatus for knee protection of embodiment. It is a general | schematic expansion horizontal longitudinal cross-sectional view of the vehicle front-back direction in the airbag apparatus for knee protection of embodiment, and respond | corresponds to the III-III site | part of FIG. It is a schematic front view which shows the airbag of the deployment state incorporating the inflator of embodiment. It is a schematic sectional drawing of the VV site | part of FIG. It is a schematic fragmentary sectional view which shows the state before the expansion | swelling of the cover part after completion of expansion | swelling of the general part of an airbag, and respond | corresponds to the VI-VI site | part of FIG. It is a figure explaining the folding process of the airbag of an embodiment. It is a schematic front view explaining the operation state in the knee protection airbag device of an embodiment in order. It is a schematic side view explaining the operation state in the knee protection airbag device of an embodiment in order. It is a schematic front view which shows the expansion | deployment state which incorporated the inflator in the airbag of the modification of embodiment.

Explanation of symbols

2 ... Steering column,
5 ... Column cover,
6 ... Key cylinder,
40 ・ 40A… Airbag,
40a ... upper end and upper edge of the airbag
41 ... Driver side wall,
42 ... Column side wall,
46 ... General Department,
47. Cover part,
48, 48A ... suture site,
48a ... outer edge part,
48b ... inner part,
50 ... suture,
E ... key,
A ... (Key accessories) Accessories,
D ... Driver,
K ... Knee.

Claims (2)

Folded and stored below the steering column on the front side of the driver and on the lower side of the key cylinder into which the key with suspended accessories can be inserted,
A knee protecting airbag that protects the driver's knee by completing deployment and inflating while projecting from the storage part to the vehicle rear side while inflating gas flows,
While having a substantially plate shape including a column side wall portion located on the steering column side when the expansion and expansion are completed, and a driver side wall portion located on the driver side,
A cover portion that is disposed in the vicinity of the left and right corners on the upper edge side at the time of completion of expansion and expansion and covers the rear side of the vehicle in the vicinity of the key cylinder, and a general portion,
The cover part is
The column side wall portion and the driver side wall portion are sewn with a breakable suture and configured to begin to expand from the vicinity of the completion of expansion of the general portion due to the breaking of the suture. A knee protection airbag characterized in that a suture site by a suture is disposed near and inside the outer edge of the cover portion.   The knee protection airbag according to claim 1, wherein the stitching line at the stitching site is formed in a one-stroke shape using a continuous suture.

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