JP4715730B2 - Knee airbag device with column - Google Patents

Description

  The present invention relates to a column-attached knee airbag device that restrains a passenger's knee by inflating and deploying a knee airbag from a column cover of a steering column at the time of a collision.

Conventionally, various knee-attached airbag devices have been proposed for the purpose of protecting the occupant's knee. For example, the following Patent Document 1 discloses a so-called column-attached knee airbag device in which an airbag module is disposed in a column cover of a steering column.
JP-A-9-104317 JP 2002-37003 A

  However, in the case of the above prior art, when the steering column is an electric column, it is conceivable that when the steering column contracts at the time of collision, the fixing portion of the steering column and the airbag module interfere with each other. Therefore, in this respect, the prior art has room for improvement.

  In view of the above-described facts, an object of the present invention is to obtain a column-attached knee airbag device that can suppress or prevent the contraction operation of a column tube during a collision as much as possible.

  The knee airbag device with a column according to the invention of claim 1 is stored in a folded state in a column cover that covers the rear end side of the steering column and receives a supply of gas from a gas generating means that operates at the time of collision. An airbag module configured to include a knee airbag that inflates and deploys to the knee side, and the airbag module and the column tube of the steering column are connected to each other, and the column tube is contracted when the column tube is contracted. It is characterized by having a link mechanism that avoids interference between the fixing portion of the steering column on the vehicle body side and the airbag module by displacing the airbag module to the lower side intersecting the column tube.

  According to a second aspect of the present invention, there is provided the column-attached knee airbag device according to the first aspect, wherein the link mechanism is arranged in an X shape in a side view and is connected to be rotatable around a connection pin. The second link is configured such that one end of the first link is connected to a fixed tube constituting the fixed side of the column tube or a fixed portion located in the vicinity thereof so as to be relatively rotatable, and the other end is air. It is connected to the module case of the bag module so as to be relatively rotatable, and one end portion of the second link is connected to the moving side tube constituting the moving side of the column tube or the moving side portion located in the vicinity thereof so as to be relatively rotatable. The end is connected to a module case included in the airbag module so as to be relatively rotatable, and the other end of the first link and the other of the second link. One of the parts is slidably supported in the long hole formed along the axial direction of the steering column, characterized in that.

  According to the first aspect of the present invention, when a collision occurs, the gas generating means is activated to generate gas. This gas flows into a knee airbag stored in a folded state in a column cover that covers the rear end side of the steering column, and inflates and deploys the knee airbag toward the occupant's knee. Thereby, a passenger | crew's knee is protected.

  By the way, when the secondary collision load of the occupant is input to the steering column, the column tube of the steering column contracts to absorb energy at the time of the secondary collision. At this time, it is conceivable that the fixing portion of the steering column to the vehicle body side relatively moves to the airbag module side and interferes with the airbag module.

  However, in the present invention, since the airbag module and the column tube of the steering column are connected by the link mechanism, when the column tube is contracted, the airbag module is attached to the column tube by utilizing the contraction operation of the column tube. It is displaced to the lower side where it intersects. This avoids interference between the fixing portion of the steering column on the vehicle body side and the airbag module.

  According to the second aspect of the present invention, the link mechanism is constituted by the first link and the second link which are arranged in an X shape in a side view and are connected so as to be relatively rotatable around the connecting pin.

  Here, at the time of contraction of the column tube, the contraction operation is performed by moving the moving side tube relative to the fixed side tube. At this time, one end of the first link is connected to the fixed side tube or a fixed side portion located in the vicinity thereof so as to be relatively rotatable, and one end of the second link is connected to the moving side tube or in the vicinity thereof. Since it is connected to the part so as to be relatively rotatable, when the moving side tube moves relative to the fixed side tube, the one end portion of the first link and the one end portion of the second link approach each other (the distance between them decreases). . Along with this, the other end of the first link and the other end of the second link also approach each other (the distance between the two decreases). At this time, one of the other end portions slides in the long hole. As a result, the module case of the air bag module is displaced downwardly intersecting the column tube by a distance corresponding to the link length, and interference between the fixing portion of the steering column to the vehicle body side and the air bag module is avoided. can do.

  Further, in the present invention, the link mechanism is arranged in an X shape in a side view and is constituted by the first link and the second link that are connected so as to be relatively rotatable around the connecting pin, so the structure is simple, The installation space can be reduced accordingly.

  As described above, the knee-attached airbag device according to the first aspect of the present invention has an excellent effect that it can suppress or prevent the contraction operation of the column tube at the time of collision as much as possible. .

  The knee-attached airbag device with a column according to the second aspect of the present invention has an excellent effect that it can be installed relatively easily in a narrow space.

[First Embodiment]
Hereinafter, an embodiment of a column-attached knee airbag device according to the present invention will be described with reference to FIGS. Note that the arrow FR in FIG. 1 indicates the front side of the vehicle, and the arrow UP indicates the upper side of the vehicle.

  FIG. 1 is a longitudinal sectional view showing an overall configuration of a column-attached knee airbag device 10 according to the present embodiment. FIG. 2 is an enlarged vertical cross-sectional view of the main part of the column-attached knee airbag device 10. In FIG. 2, the steering column 12 is drawn in a horizontal direction.

  As shown in these drawings, an opening 16 for inserting a steering column is formed on the driver's seat side of the instrument panel 14, and the steering column 12 is disposed in a state where the steering column 12 is tilted forward through the opening 16. Yes. A column cover 18 that covers the rear end side of the steering column 12 is disposed at a position facing the opening 16 of the instrument panel 14 so as to protrude toward the cabin 19. The column cover 18 has a vertically divided structure, and is composed of a column upper cover 20 and a column lower cover 22.

(Overall structure of steering column 12)
The steering column 12 of the present embodiment is an electric steering column, and in addition to an energy absorbing mechanism that absorbs energy by contracting when a secondary collision load in the column axial direction is input during a frontal collision, an occupant switch A tilting mechanism that adjusts the vertical angle of the steering wheel by swinging (swinging) the steering column up and down around the swing center axis by operation and a switch operation of the occupant switch the steering wheel in a predetermined stroke in the column axis direction. A telescopic mechanism that adjusts the front-rear position of the steering wheel by sliding within the range is provided.

  When the specific structure is outlined, the steering column 12 is provided with a cylindrical column tube 26, and a steering main shaft 28 is rotatably supported on the shaft core portion of the column tube 26. The steering main shaft 28 is divided into two in the column axis direction, and the upper shaft 28A and the lower shaft (not shown) are connected by spline fitting. Therefore, the upper shaft 28A can move relative to the lower shaft within a predetermined stroke range, but the upper shaft 28A cannot rotate relative to the lower shaft. A steering wheel 34 to which a driver's steering force is applied is fixed to a rear end portion of the upper shaft 28A by a lock nut. Accordingly, when the steering wheel 34 is rotated, the upper shaft 28A and the lower shaft are integrally rotated around the axis, and the intermediate shaft (not shown) connected to the lower shaft by a universal joint is rotated. The steering force is transmitted to the steering gear box.

  The column tube 26 that covers the steering main shaft 28 is also divided into two in the column axial direction (double tube structure), and is disposed on the inner tube 36 disposed on the passenger side and on the opposite passenger side (steering gear box side). The outer tube 38 is connected by spline fitting. Further, the outer tube 38 is set to have a diameter larger than that of the inner tube 36, and the inner tube 36 slides into the outer tube 38 and contracts at the time of a secondary collision with the occupant's steering wheel 34. Further, the outer tube 38 is supported by a pipe-like instrument panel reinforcement (not shown) that is a high-strength and high-rigidity member that extends in the instrument panel 14 along the vehicle width direction.

  Supplementing this point, at a predetermined position in the longitudinal direction of the instrument panel reinforcement, a steering support having portions extending to both the vehicle front side and the vehicle rear side across the instrument panel reinforcement in a plan view is fixed by welding or the like. Yes. On the front end side of the steering support, a lower bracket (not shown) is fixed to the upper front end of the outer tube 38 so as to be swingable about the swing center axis. Further, a housing 40 is fixed to the rear end side of the steering support and is formed in a substantially rectangular frame shape in which the column tube 26 is disposed in a penetrating state. During the tilt operation, the column tube 26 moves up and down in the housing 40. In other words, since a part of the tilt mechanism and a part of the telescopic mechanism part of the electric tilt / telescopic drive mechanism part are integrated with the outer tube 38, the outer tube 38 is supported by the tilt / telescopic drive mechanism part. As a result, the column tube 26 is hollowly supported in the substantially rectangular frame-shaped housing 40, and the steering column 12 is allowed to move up and down by a tilt operation.

(Overall configuration of the knee-attached airbag device 10)
Next, the overall configuration of the column-attached knee airbag device 10 will be described.

  The column-attached knee airbag device 10 includes a metal module case 48 formed in a substantially box shape, and an inflator as a gas generating means formed in a substantially cylindrical shape and accommodated on the inner rear end side of the module case 48. 50, and an airbag module 54 including a knee airbag 52 stored in a folded state on the inner front end side of the module case 48, and a lower surface side serving as an opening side of the airbag module 54 is closed. And an airbag door 60.

  A plurality of hook portions 56 are formed at predetermined intervals on the front wall portion 48A and the rear wall portion 48B of the module case 48. Correspondingly, on the inner side surface (the surface facing the inner tube 36) of the column lower cover 22, the front wall portion 22A and the rear wall portion 22B are provided on the inner tube 36 side at a predetermined interval in the column axial direction. It is erected. The front wall portion 22 </ b> A and the rear wall portion 22 </ b> B are formed with a locking hole 58 in which the hook portion 56 can be locked, and the hook module 56 is locked in the locking hole 58, whereby the airbag module 54. The open side of is closed.

  Further, the airbag door 60 is formed at a portion between the front wall portion 22A and the rear wall portion 22B of the column lower cover 22, and along the tear line (breaking portion) 62 configured as a thin portion in this embodiment. When the column lower cover 22 is broken, the airbag door 60 is deployed in front, rear, left and right.

  Moreover, although the knee airbag 52 is folded by bellows folding in FIG. 1, it is not restricted to this, You may fold by roll folding and you may fold combining both. Further, supplementing the deployed shape of the knee airbag 52, the central portion 52A that expands below the position where the steering column 12 is disposed is relatively thin due to the presence of the column lower cover 22. Both side portions 52B that expand on the side of the position are relatively thick because they expand between the instrument panel 14 and the occupants' knees.

  The airbag module 54 described above is an annular main body of a combination switch 68 fixed below the rear end side of the inner tube 36 of the steering column 12 and near the lower end 40A of the housing 40 and the rear end portion of the inner tube 36 described above. The portion 68A is disposed between the lower portion 68A ′.

(Structure of the main part of the column-attached knee airbag device 10)
Next, a configuration of a main part of the column-attached knee airbag device 10 will be described.

  As shown in FIGS. 2 and 3, the module case 48 of the airbag module 54 described above is connected to the column tube 26 via a link mechanism 70.

  If it demonstrates in detail, the link mechanism 70 is comprised by the 1st link 72 and the 2nd link 74 which are arrange | positioned at X shape by side view. One end portion 72 </ b> A of the first link 72 is pin-coupled via a first bracket 76 to the rear end portion of the outer tube 38 as a fixed side tube constituting the fixed side of the column tube 26. A mounting bracket 78 is fixed to the bottom wall portion 48 </ b> C of the module case 48, and the other end portion 72 </ b> B of the first link 72 is pin-coupled to the mounting bracket 78.

One end portion 74A of the second link 74 has a second bracket 80 on the rear end side of the inner tube 36 as a moving side tube constituting the moving side of the column tube 26 (adjacent position of a main body portion 68A of a combination switch 68 described later). Is pinned through. A long hole 82 is formed in the mounting bracket 78 along the column axial direction, and the other end 74B of the second link 74 is slidably pin-coupled (supported) in the long hole 82.
Moreover, the 1st link 72 and the 2nd link 74 are connected so that relative rotation is possible by the connection pin 84 arrange | positioned in the site | part which both cross | intersect.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  When a frontal collision occurs (or when a frontal collision is predicted), the state is detected by a collision detection unit (not shown) and output to the airbag ECU. When the airbag ECU determines that the airbag is activated, the driver side airbag device is activated to inflate the driver seat airbag on the steering wheel 34 and the column-attached knee airbag device 10 is also activated. Is done. That is, a predetermined current is passed through the inflator 50 of the column-attached knee airbag device 10 to activate the inflator 50. Thereby, gas is generated from the inflator 50 and supplied into the knee airbag 52 stored in the folded state, and the knee airbag 52 is inflated. When the inflation pressure of the knee airbag 52 acting on the column lower cover 22 reaches a predetermined value, the column lower cover 22 breaks along the tear line 62 set in the column lower cover 22, and the front door 60 </ b> A of the airbag door 60. In addition, the rear door 60B is expanded forward and backward, and a left door and a right door (not shown) are expanded left and right. As a result, the knee airbag 52 is inflated and deployed below and to the side of the steering column 12, and the occupant's knees are received by the left and right side portions 52B interposed between the instrument panel 14 and the occupant's knees. Protected.

  The impact at the time of a frontal collision is also absorbed by the energy absorption mechanism of the steering column 12. That is, when a frontal collision occurs, a thrust load from the steering gear box is input to the intermediate shaft, but energy is absorbed by the contraction of the intermediate shaft. Further, when the upper body of the occupant is received by the driver's seat airbag from the steering wheel 34 side, a load (arrow F in FIG. 1) is input to the steering column 12 through the steering wheel 34 in the axial direction. Is done. When the input load is equal to or greater than a predetermined value, the steering main shaft 28 and the column tube 26 contract (the upper side shaft 28A relatively moves axially into the lower side shaft, and the inner tube 36 becomes the outer tube. It moves in the axial direction relatively to the 38 side). The frictional energy generated in this process absorbs the collision energy input from the steering wheel 34 side.

  By the way, when the passenger's secondary collision load (arrow F in FIG. 1) is input to the steering column 12 and the column tube 26 of the steering column 12 contracts, the housing is a fixed portion of the steering column 12 to the vehicle body side. It is conceivable that the lower portion 40 </ b> A of the 40 moves relatively to the airbag module 54 side and interferes with the airbag module 54.

  However, in the present embodiment, since the airbag module 54 and the column tube 26 of the steering column 12 are connected by the link mechanism 70, the following operation is obtained.

  That is, if the state shown in FIG. 2 is a state when the steering column 12 is not contracted, when the column tube 26 is contracted from this state, as shown in FIG. 3, the inner tube 36 which is a moving side (sliding) tube. Is slid into the outer tube 38, which is a fixed side tube, to perform a contraction operation. At this time, one end 72A of the first link 72 is connected to the rear end of the outer tube 38 via the first bracket 76 so as to be relatively rotatable, and the one end 74A of the second link 74 is connected to the rear of the inner tube 36. Since it is connected to the end side (position adjacent to the main body 68 </ b> A of the combination switch 68) via the second bracket 80, when the inner tube 36 moves relative to the outer tube 38, the first link 72. One end portion 72A of the second link 74 approaches one end portion 72A of the second link 74 (that is, the relative distance between them decreases). Along with this, the other end portion 72B of the first link 72 and the other end portion 74B of the second link 74 also approach each other (that is, the relative distance between them decreases). At this time, the other end 74 </ b> B of the second link 74 slides in the long hole 82. As a result, the module case 48 of the airbag module 54 is displaced downwardly intersecting the column tube 26 by a distance corresponding to the link length, and the lower portion 40A of the housing 40, which is a fixed portion of the steering column 12 to the vehicle body side. And the module case 48 of the airbag module 54 can be prevented from interfering with each other. As a result, according to the present embodiment, it is possible to suppress or prevent the contraction operation of the column tube 26 from being inhibited at the time of a frontal collision as much as possible.

  Moreover, in the present embodiment, the airbag module 54 is forcibly and mechanically displaced to the interference avoidance position by the link mechanism 70 using the contraction operation of the column tube 26, so that the reliability of the operation is very high. high.

  Furthermore, in the present embodiment, the link mechanism 70 is arranged in an X shape in a side view and is configured by the first link 72 and the second link 74 that are connected so as to be relatively rotatable around the connecting pin 84. The structure of the mechanism is also simple. Therefore, it can be arranged relatively easily in a narrow space.

[Supplementary explanation of the above embodiment]
(1) In this embodiment described above, the column-attached knee airbag device 10 is activated by a frontal collision. However, the present invention is not limited to this, and a pre-crash sensor is mounted in the center of the front bumper. Thus, the column-attached knee airbag device 10 may be activated even when the frontal collision is predicted (forecast).

  (2) In the above-described embodiment, a configuration in which the module case 48 is displaced downward using the link mechanism 70 using the metal module case 48 is adopted, but the material has both flexibility and flexibility. It does not exclude a module case made of a cloth or the like. In this case, the inflator is displaced downward by the link mechanism. That is, a configuration may be adopted in which a bolt standing from the inflator is fixed to the mounting bracket and the inflator is displaced downward using the link mechanism 70 when the column is contracted. In this case, the fabric airbag case or knee airbag remains due to the internal pressure of the knee airbag, and may slightly interfere with the lower portion 40A of the housing 40. However, the airbag case and the knee airbag can be easily deformed. Therefore, the contraction operation of the column tube is not hindered at all.

  (3) In the present embodiment described above, the one end 72A of the first link 72 is connected to the rear end of the outer tube 38, and the one end 74A of the second link 74 is connected to the rear end of the inner tube 36. However, the present invention is not limited to this, and the one end portions 72A and 74A may be coupled to an object other than the tube located in the vicinity of the tube so as to be relatively rotatable. For example, the first link 72 may be coupled to the lower portion 40A of the housing 40 so as to be relatively rotatable, and the second link 74 may be relatively rotated to the lower portion 68A ′ of the main body portion 68A of the combination switch 68. You may connect to. In that case, it is preferable that the attachment positions of the one end portion 72A of the first link 72 and the one end portion 74A of the second link 74 are parallel to the column tube 26.

  (4) In the present embodiment described above, the X-shaped link mechanism 70 is used in a side view, but the present invention is not limited to this, and other link mechanisms may be used. For example, if stability may be slightly lacking, but the space in the direction perpendicular to the column axis is not enough to install the X link, the link is formed in a mountain shape (upper half of the X link) A plate-like member having the column axis direction as the longitudinal direction may be fixed to the pins constituting the connection point by welding or the like.

It is a longitudinal cross-sectional view which shows the whole structure of the knee airbag apparatus with a column which concerns on this embodiment in a side view. It is a principal part expanded longitudinal sectional view which expands and shows the principal part of the column-attached knee airbag device shown in FIG. FIG. 3 is an operation explanatory view corresponding to FIG. 2 showing a state in which the column tube is contracted from the state shown in FIG. 2.

Explanation of symbols

10 Knee airbag device with column 12 Steering column 18 Column cover 26 Column tube 36 Inner tube (moving side tube)
38 Outer tube (fixed side tube)
40 Housing (fixed part to the vehicle body)
48 Module case 50 Inflator (gas generating means)
52 knee airbag 54 airbag module 70 link mechanism 72 first link 72A one end 72B other end 74 second link 74A one end 74B other end 82 long hole 84 connecting pin

Claims (2)

A knee cover that is stored in a folded state in a column cover that covers the rear end side of the steering column and that is inflated and deployed to the occupant's knee side upon receipt of gas supplied from the gas generating means that operates in the event of a collision. An airbag module;
This airbag module is connected to the column tube of the steering column, and when the column tube is contracted, the airbag module is displaced downward by crossing the column tube by using the contraction operation of the column tube. A link mechanism for avoiding interference between the fixing part to the vehicle body side and the airbag module,
A knee-attached airbag device having a column. The link mechanism is configured by a first link and a second link which are arranged in an X shape in a side view and are connected so as to be relatively rotatable around a connecting pin.
One end of the first link is connected to a fixed tube constituting the fixed side of the column tube or a fixed portion located in the vicinity of the first tube, and the other end can be rotated relative to the module case of the airbag module. Connected to
One end of the second link is connected to a moving tube constituting the moving side of the column tube or a moving side portion located in the vicinity thereof so as to be relatively rotatable, and the other end is relatively rotated to a module case included in the airbag module. Concatenated,
Further, one of the other end of the first link and the other end of the second link is slidably supported in a long hole formed along the axial direction of the steering column.
The knee-attached airbag device with a column according to claim 1.

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