JP4254451B2 - Air bag device for knee protection - Google Patents

Description

  The present invention relates to a knee protection airbag device capable of protecting the knees of a seated occupant by an airbag that is inflated by inflating gas.

Conventionally, an airbag device for protecting a knee for protecting an occupant's knee has a configuration in which an airbag incorporating an inflator is folded and stored in a case (see, for example, Patent Document 1). The inflator was provided with a main body capable of discharging the inflation gas, and a mounting bolt for mounting and fixing the inflator to the case by projecting so as to be substantially orthogonal to the axial direction of the main body. In the conventional knee protection airbag device, the end of the inflator body built into the airbag protrudes from the case through the insertion hole formed in the airbag and the lead wire is connected. It was the composition to connect with.
JP 2003-205816 A

  However, in the conventional knee protection airbag device, the inner diameter dimension of the insertion hole formed in the airbag is set to be substantially the same as the outer dimension of the inflator body from the viewpoint of ensuring the sealing performance. Therefore, since it is difficult to insert the inflator into the airbag through the insertion hole, an opening that allows the inflator to be easily inserted into the airbag is provided in the airbag. As a result, after the inflator is inserted into the airbag, it is necessary to sew and close the opening, which increases the number of manufacturing steps for the airbag.

  The present invention solves the above-described problems, and an object thereof is to provide a knee protection airbag device in which an inflator can be easily inserted into an airbag and the number of manufacturing steps and cost can be reduced.

The airbag device for knee protection according to the present invention is disposed in front of the knees of a seated occupant,
A folded airbag, an inflator that is accommodated in the airbag and supplies inflation gas to the airbag, a case that is substantially box-shaped with the vehicle rear side opened, and that accommodates the airbag and the inflator; Configured with
The inflator
A body capable of discharging inflation gas;
A projection bolt for projecting so as to be substantially orthogonal to the axial direction of the main body, and for fixing the inflator to the case,
Configured with
Airbag
With an insertion hole capable of projecting the end of the main body in the inflator and a mounting hole capable of projecting the mounting bolt,
For protecting the knee, the main body of the inflator protruding from the insertion hole is protruded from the case, and the mounting bolt of the inflator protruding from the mounting hole is fixed to the case together with the inflator. In the airbag device,
The insertion hole has the same inner diameter as the outer diameter of the main body of the inflator,
The peripheral edge of the insertion hole in the airbag is provided with a slit communicating with the insertion hole, and is accommodated in the case with the slit closed so that the airbag can be brought into contact with the inner peripheral surface when the airbag is deployed and inflated. ,
The slit is set to a length that allows the main body of the inflator to be inserted together with the mounting bolt together with the insertion hole , and the opening of the slit can be suppressed during expansion and expansion of the airbag. A direction from the insertion hole side to the front end side is arranged so as to be substantially along the same direction as the tension direction of the base fabric.

  In the knee protecting airbag device of the present invention, the insertion hole formed in the airbag allows the slit to communicate with the periphery. For this reason, if the slit is expanded when the inflator is inserted into the airbag, the inflator can be easily accommodated in the airbag using the insertion hole and the slit. As a result, unlike the conventional knee protection airbag device, it is not necessary to provide the airbag with an opening for accommodating the inflator, and the operation of stitching the opening is not necessary. As a result, the manufacturing cost of the knee protection airbag device can be reduced, and at the same time, the workability of inserting the inflator into the airbag can be improved, so that the number of manufacturing steps of the knee protection airbag device can be reduced. Can do.

  Therefore, in the knee protection airbag device of the present invention, the inflator can be easily inserted into the airbag, and the number of manufacturing steps and costs can be reduced.

  In the knee protection airbag device according to the present invention, in the state in which the airbag is housed in the case, the slit disposed at the periphery of the insertion hole is closed, and the portion of the periphery of the insertion hole is inflated and expanded by the airbag. Sometimes, it is stored so that it can contact the inner peripheral surface of the case. Therefore, when the airbag is deployed and inflated, the slit does not open due to contact with the inner peripheral surface of the case, and the inflation gas discharged from the inflator can be prevented from leaking from the slit, and the air at the completion of the inflation can be prevented. Gas leakage from the bag can be suppressed.

Further, in the knee protecting airbag device of the present invention, even if the base fabric around the periphery of the insertion hole is pulled when the airbag is deployed and inflated, the direction in which the slit extends from the insertion hole side to the tip side is the tensile direction of the base fabric toward the same direction as, since it is arranged to be substantially along, upon airbag deployment, that slit is opened, it can be minimized. Therefore, it is possible to further suppress the expansion gas discharged from the inflator from leaking from the slit.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 4, the knee protection airbag device S of the embodiment is a steering on the front side of the vehicle of the driver MD so as to protect the knee K (KL / KR) of the driver MD as an occupant. It is disposed below the column 9.

  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 9 includes a column main body 10 connected to the steering wheel 8 and a column cover 13 disposed so as to cover the column main body 10 below the steering wheel 8. Has been. The column body 10 includes a main shaft 11 and a column tube 12 that covers the periphery of the main shaft 11.

  The column cover 13 is made of a synthetic resin having a substantially rectangular tube shape, and is disposed along the axial direction of the column main body 10 so as to cover the column main body 10. A rear surface 13a of a portion of the column cover 13 that protrudes from an instrument panel (hereinafter abbreviated as “instrument panel”) 14 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 accommodates a folded airbag 44, an inflator 37 that supplies inflation gas to the airbag 44, the folded airbag 44 and the inflator 37, and opens the vehicle rear side. The case 17 and an airbag cover 26 that covers the vehicle rear side of the opening in the case 17 are provided.

  As shown in FIGS. 2 to 4, the case 17 is made of sheet metal and is disposed on the lower side of the steering column 9, and has a box-shaped main body 18 and a panel extending outward from the rear end of the main body 18. Part 23. The main body 18 includes a substantially square cylindrical peripheral wall 19 and a bottom wall 21 that closes the vehicle front side of the peripheral wall 19, and includes a substantially rectangular opening 18 a on the vehicle rear side. ing. A plurality of locking claws for assembling upper and lower connecting wall portions 29 and 30 (to be described later) of the airbag cover 26 to the case 17 on the outer surface sides of the wall portions 19 a and 19 b facing each other in the vertical direction of the peripheral wall portion 19. 20 is provided. In the embodiment, the locking claw 20 is integrated with the panel portion 23 and is separated from the main body portion 18. Each locking claw 20 has a substantially Z-shaped cross section and is inserted into the locking holes 29a and 30a of the connecting walls 29 and 30 in the airbag cover 26 to lock the peripheral edges of the locking holes 29a and 30a. It is possible.

  Further, the side wall 19c of the peripheral wall 19 is formed with an insertion hole 19d through which a main body 38 to be described later of the inflator 37 can be inserted (see FIG. 3). Further, two insertion holes 21 a for allowing the attachment bolts 39 c of the inflator 37 to be inserted are formed in the bottom wall portion 21.

  The panel portion 23 is formed separately from the main body portion 18 and surrounds the periphery of the opening 18 a of the case 17. As shown in FIG. 4, the panel portion 23 is provided with a connecting portion 24 for connecting and fixing the case 17 to the body 1 side. In the case of the embodiment, the connecting portions 24 are formed at five locations, two locations above the main body portion 18, near the lower left corner, and near the upper and lower ends of the right side. As shown in FIG. 4, brackets 4, 5, 6, and 7 are disposed on the body 1 side to which the connecting portions 24 are connected. The brackets 4 and 5 for connecting the connecting portions 24A and 24B disposed on the upper side are connected to the instrument panel reinforcement 2 on the body 1 side. The brackets 6 and 7 for connecting the connecting portions 24C and 24D disposed on the lower side are connected to a center brace, a front body pillar, etc. (not shown) on the body 1 side. Further, as shown in FIG. 2, the panel portion 23 is formed with an insertion hole 23 a through which the upper wall portion 29 of the airbag cover 26 is inserted.

  The airbag cover 26 is formed of a thermoplastic elastomer such as olefin, and is configured to cover the vehicle rear side of the case 17 and is assembled to the case 17. The airbag cover 26 is disposed on the lower panel 14b side of the instrument panel 14 including the upper panel 14a and the lower panel 14b. The airbag cover 26 includes a door disposition portion 28 disposed near the opening 18a of the case 17 and a door arrangement. A covering portion 27 is provided around the installation portion 28 so as to be able to cover the vehicle rear side of the panel portion 23. The door arrangement portion 28 includes a door portion 35 and upper, lower, left, and right side wall portions 29, 30, 31, and 32 that are disposed near the periphery of the door portion 35. Yes.

  The door portion 35 is formed to be slightly larger than the opening 18a of the case 17 and has a substantially rectangular plate shape covering the opening 18a. The door part 35 is comprised from the two door parts opened to an up-down direction in embodiment. The door portion 35 is provided with a hinge portion 34 serving as a rotation center at the time of opening at the upper end and the lower end, and the portion around the door portion 35 is substantially H-shaped when viewed from the vehicle rear side. The planned fracture portion 33 is arranged.

  The upper side wall portion 29, the lower side wall portion 30, the left side wall portion 31, and the right side wall portion 32 are adjacent to the outer peripheral side of the peripheral wall portion 19 in the case main body portion 18 so as to protrude to the vehicle front side. It is arranged. In the case of the embodiment, the upper side wall portion 29 disposed in the vicinity of the upper wall portion 19a of the peripheral wall portion 19 and the lower side wall portion 30 disposed in the vicinity of the lower wall portion 19b serve as the airbag cover 26. The connecting wall is connected to the case 17. A plurality of locking holes 29a and 30a for locking the locking claws 20 are formed in the upper and lower side wall portions 29 and 30, respectively.

  As shown in FIGS. 2 and 3, the inflator 37 is configured as a cylinder type whose axial direction is disposed along the left-right direction of the vehicle, and includes a substantially columnar body 38 and a diffuser 39. . A plurality of gas discharge ports 38 a are arranged on one end side of the main body 38. Then, a connector 41 connected with an operation signal input lead wire 42 is connected to the other end 38 b side of the main body 38. The diffuser 39 includes a substantially cylindrical sheet metal holding cylinder portion 39a capable of covering the main body 38, and a plurality (two in the embodiment) of mounting bolts 39c protruding from the holding cylinder portion 39a. Yes. The holding cylinder part 39a has a plurality of gas outlets 39b through which the expansion gas discharged from the gas discharge port 38a of the main body 38 can flow out open on the vehicle rear side surface of the holding cylinder part 39a mounted in the vehicle. Configured.

  The inflator 37 has an airbag operating circuit mounted on the vehicle via a lead wire 42 together with an airbag device (not shown) mounted on the steering wheel 8 when a frontal collision of the vehicle is detected. An operation signal is input.

  The airbag 44 is formed from a single woven fabric made of flexible polyester, polyamide yarn, or the like, and as shown in FIGS. The mounting portion 46 accommodates the inflator 37 on the lower end side, and a protection portion 45 that is disposed above the mounting portion 46 and has a width dimension in the left-right direction larger than that of the mounting portion 46. The attachment portion 46 is housed in the case main body portion 18 when the airbag 44 is completely inflated and inflated, and is a portion held by the case main body portion 18 using the inflator 37.

  Further, the airbag 44 folds an airbag material made of a single woven fabric at a lower end portion of the airbag 44, and sews tethers 54 and 55, which will be described later, with sutures, and also folds and opposes the portion. These peripheral edges are formed by sewing with a suture thread. The airbag 44 includes an occupant side wall portion 51 on the driver MD side and a vehicle body side wall portion 52 on the column cover 13 side each having a substantially fan shape.

  The tethers 54 and 55 are disposed in the region of the protective portion 45 in the airbag 44, and are protected by regulating the separation distance between the occupant side wall portion 51 and the vehicle body side wall portion 52 when the airbag 44 is deployed and inflated. The portion 45 can be deployed so as to smoothly enter between the knee K of the driver MD and the column cover 13. In the case of the embodiment, the tethers 54 and 55 are arranged in two vertical stages along the left-right direction. Each of the tethers 54 and 55 is composed of two cloth materials, and each cloth material is sewn to the occupant side wall portion 51 and the vehicle body side wall portion 52, and the end portions of the corresponding cloth materials are sewn together. Is formed.

An insertion hole 47 having a substantially circular opening through which the main body 38 of the inflator 37 can be inserted is formed in the right edge portion of the attachment portion 46 on the lower side of the vehicle body side wall portion 52 (which becomes the left edge portion in FIG. 5). Yes. The insertion hole 47 has an inner diameter dimension substantially the same as the outer diameter dimension of the inflator body 38. In addition, a slit 48 is arranged around the insertion hole 47 so as to communicate with the insertion hole 47. When the airbag 44 is deployed and inflated, the slit 48 faces in the same direction as the pulling direction of the base fabric of the airbag 44 at the periphery of the insertion hole 47 and is substantially along the direction from the insertion hole 47 side to the tip 48a side. In the case of the embodiment, the tip 48a side is arranged so as to protrude toward the outer edge side of the airbag 44 (see FIG. 5). Moreover, when the slit 48 is expanded as shown by a two-dot chain line in FIG. 5, the length of the inflator 37 and the mounting bolt 39 c along with the insertion hole 47 can be inserted. As shown in FIG. 3, the peripheral portion of the insertion hole 47 contacts the inner peripheral surface of the case main body 18 when the airbag 44 is folded and stored in the case main body 18 or when the airbag 44 is inflated. It will be accommodated in the case body 18 so as to come into contact.

  Further, two attachment holes 49 and 49 into which the attachment bolts 39c of the inflator 37 can be inserted are formed in the portion of the attachment portion 46 on the lower side of the vehicle body side wall portion 52.

  Next, the mounting of the knee protection airbag device S of the embodiment on a vehicle will be described. First, the inflator 37 is stored in the airbag 44. Specifically, the inflator 37 is inserted into the attachment portion 46 of the airbag 44 from the gas discharge port 38a side so that the insertion hole 47 is inserted while the slit 48 is opened. Then, the mounting bolt 39 c is protruded from each mounting hole 49, and the end portion 38 b of the inflator main body 38 is protruded from the insertion hole 47, and the inflator 37 is accommodated in the airbag 44. After the inflator 37 is stored, the slit 48 around the insertion hole 47 is closed.

  Thereafter, the airbag 44 is folded. Specifically, as shown in FIG. 7A, from the state where the occupant side wall 51 and the vehicle body side wall 52 are overlapped and flattened, the left and right edges 44a and 44b are placed on the occupant side wall 51 side. Fold it up. Next, as shown in FIGS. 7B and 7C, the upper edge 44c of the airbag 44 is wound around the side wall portion 52 so as to be wound with a crease along the left-right direction, and is turned into D in FIG. As shown, the left and right edges 57a and 57b of the roll-folded portion 57 are folded on the side of the occupant side wall 51 so that the case body 18 can be accommodated, and the folding of the airbag 44 is completed. Thereafter, the airbag 44 is wrapped with a wrapping material (not shown) that can be broken to prevent it from collapsing. At this time, the mounting bolt 39c of the inflator 37 protruding from the mounting hole 49 and the insertion hole 47 and the end 38b of the main body 38 are projected from the wrapping material.

  Next, the mounting bolt 39c of the inflator 37 is protruded from the insertion hole 21a and fixed with the nut 40, and the end 38b of the inflator body 38 is protruded from the insertion hole 19d so that the inflator 37 is folded. 44 is housed in the case body 18.

  Thereafter, the airbag cover 26 is assembled to the case 17. Specifically, the airbag cover 26 is moved to the case 17 side so that the upper wall portion 29 is inserted into the insertion hole 23a of the panel portion 23, and the locking hole portions of the upper and lower wall portions 29 and 30 are moved. The airbag cover 26 can be assembled to the case 17 by inserting the locking claws 20 into the 29a and 30a and locking them to the peripheral edges of the locking holes 29a and 30a.

  Then, each connecting portion 24 of the case 17 is attached and fixed to the body 1 side using the brackets 4, 5, 6, and 7, and at the same time, the connector 41 to which the lead wire 42 is connected is connected to the inflator body 38. . After that, if the instrument panel 14 and the under cover 15 (see FIGS. 1 and 2) are attached, the airbag device S can be mounted on the vehicle.

  If the operation signal is input to the inflator body 38 through the lead wire 42 after the airbag device S is mounted on the vehicle, the inflation gas is discharged from the gas discharge port 38a of the inflator 37, and the inflation gas is converted into the diffuser 39. Then, the air flows into the airbag 44 through the gas outlet 39b. The airbag 44 is inflated to break a wrapping material (not shown), presses the door portion 35 of the airbag cover 26, and breaks the planned break portion 33. And the door part 35 will open up and down centering on the hinge part 34, and the airbag 44 will expand | deploy and inflate as shown with the dashed-two dotted line of FIG.

  And in the airbag apparatus S of embodiment, the insertion hole 47 formed in the attaching part 46 of the airbag 44 makes the slit 48 communicate with the periphery. Therefore, if the slit 48 is expanded when the inflator 37 is inserted into the airbag 44, the inflator 37 can be easily stored in the airbag 44 using the insertion hole 47 and the slit 48. be able to. As a result, unlike the conventional knee protection airbag device, it is not necessary to provide the airbag with an opening for accommodating the inflator, and the operation of stitching the opening is not necessary. As a result, the manufacturing cost of the knee protection airbag device S can be reduced, and at the same time, the workability of inserting the inflator 37 into the airbag 44 is improved, and therefore the number of manufacturing steps of the knee protection airbag device S is improved. Can also be reduced.

  Therefore, in the knee protection airbag device S of the embodiment, the operation of inserting the inflator 37 into the airbag 44 is easy, and the number of manufacturing steps and cost can be reduced.

  In the airbag device S of the embodiment, in the state in which the airbag 44 is housed in the case 17, the slit 48 disposed at the periphery of the insertion hole 47 is closed, and the portion 46 a at the periphery of the insertion hole 47 is When the bag 44 is deployed and inflated, the bag 44 is stored so as to be able to contact the inner peripheral surface of the peripheral wall portion 19 of the case body 18 (see FIG. 3). Therefore, when the airbag 44 is deployed and inflated, the slit 48 does not open due to contact with the inner peripheral surface of the peripheral wall portion 19 of the case body 18, and the inflation gas discharged from the inflator 37 leaks from the slit 48. This can suppress the gas leakage from the airbag 44 when the inflation is completed.

Further, in the airbag apparatus S of the embodiment, the slit 48 faces substantially the same direction as the tensile direction of the base fabric of the airbag 44 that forms the peripheral portion 46a of the insertion hole 47 when the airbag is deployed and inflated. It is the structure which arrange | positions the direction which goes to the front-end | tip 48a side from the insertion hole 47 side so that it may follow. That is, in the airbag device S of the embodiment, even when the portion 46a at the periphery of the insertion hole 47 is pulled when the airbag 44 is deployed and inflated, the slit 48 is in the same direction as the tensile direction of the base fabric constituting the portion 46a. Since the direction from the insertion hole 47 side to the front end 48a side is arranged so as to be substantially along, the opening of the slit 48 can be suppressed as much as possible when the airbag 44 is deployed and inflated. Therefore, it is possible to further suppress the expansion gas discharged from the inflator 37 from leaking from the slit 48. Of course, if this point is not taken into consideration, the slit may be disposed so as to intersect with the pulling direction of the base fabric of the airbag 44 constituting the portion 46a around the insertion hole 47.

  In the embodiment, the knee protection airbag device S that is disposed below the steering column 9 and protects the knee of the driver MD is described as an example. However, the knee protection airbag device of the present invention is described. Can be applied to a knee protection airbag device disposed in front of the passenger seat in order to protect the knees of the passenger seated in 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. It is a general | schematic expanded longitudinal cross-sectional view of the vehicle front-back direction of the airbag apparatus for knee protection. It is a schematic sectional drawing of the III-III site | part of FIG. It is the schematic front view seen from the vehicle rear side which shows the use condition of the airbag apparatus for knee protection. It is a rear view of the airbag used by embodiment. It is a general | schematic expanded sectional view of the VI-VI site | part of FIG. It is the schematic which shows folding of the airbag of embodiment.

Explanation of symbols

17 ... Case,
18 ... body part,
26 ... Airbag cover,
37 ... Inflator,
38 ... body,
38b ... the end,
39c ... mounting bolts,
44 ... Airbag,
47 ... insertion hole,
48 ... Slit,
48a ... tip,
49 ... Mounting hole,
K (KL / KR) ... Knee,
MD ... Crew,
S: Air bag device for knee protection.

Claims (1)

Placed in front of the knees of the seated occupant,
A folded airbag, an inflator that is accommodated in the airbag and supplies inflation gas to the airbag, and has a substantially box shape with an opening on the rear side of the vehicle, and accommodates the airbag and the inflator. A case to be configured, and
The inflator is
A body capable of discharging inflation gas;
And a mounting bolt for mounting and fixing the inflator to the case while projecting so as to be substantially orthogonal to the axial direction of the main body,
Configured with
The airbag is
With an insertion hole capable of projecting the end of the main body in the inflator and a mounting hole capable of projecting the mounting bolt,
The inflator body protruded from the insertion hole is protruded from the case, and the inflator mounting bolt protruded from the attachment hole is attached to the case and fixed to the case together with the inflator. In the airbag device for knee protection with a fixed configuration,
The insertion hole has an inner diameter dimension substantially the same as an outer diameter dimension of the main body of the inflator,
A state in which the periphery of the insertion hole in the airbag is provided with a slit communicating with the insertion hole, and the slit is closed so as to be able to contact the inner peripheral surface of the case when the airbag is deployed and inflated In the case,
The slit is set to a length that allows the main body of the inflator to be inserted together with the mounting bolt together with the insertion hole , and the slit can be prevented from opening when the airbag is deployed and inflated. A direction from the insertion hole side to the front end side is arranged so as to be substantially in line with the pulling direction of the airbag fabric at the periphery of the hole. Air bag device for knee protection.

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