JP2005297840A - Active knee bolster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active knee bolster which is lightweight and capable of enhancing the absorbing performance of the collision energy. <P>SOLUTION: An actuator 32 of the active knee bolster 24 has a double structure consisting of an inner cylinder 48 with a lower limb constraint unit 30 supported thereby and an outer cylinder 46 which is fixed to an instrument panel reinforcement 33 of a vehicle body, and movably supports the inner cylinder 48 with an inflator 60 connected thereto. A plurality of balls 64 to stop the movement of the inner cylinder 48 by the gradual deformation of the outer cylinder 46 when the inner cylinder 48 is subjected to the load over the predetermined value forward of the vehicle body are arranged between an inclined portion 48D of the inner cylinder 48 and the outer cylinder 46. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an active knee bolster, and more particularly to an active knee bolster mounted on a vehicle such as an automobile.

Conventionally, in an active knee bolster mounted on a vehicle such as an automobile, a holding piece of a knee protection device that restrains an occupant's lower limb is movable in a pipe-shaped guide portion, and the knee protection device is attached to a seat. When it comes into contact with the seated occupant's knee, an impact load is applied at an angle shifted with respect to the axial direction of the holding piece, and the restraining teeth provided on the guide portion and the holding piece are arranged between the guide portion and the holding piece. A configuration is known in which a holding piece is held at a knee restraint position by deforming and engaging a tube made of a material that can be easily deformed (see, for example, Patent Document 1).
Japanese Patent No. 2528403

  However, the active knee bolster in the configuration of Patent Document 1 has a triple structure because the tube is arranged between the guide portion and the holding piece, and the thickness of the guide portion and the thickness of the holding piece to deform the tube. Thickness must be increased to increase strength. This increases the weight of the active knee bolster. Further, when the knee protection device comes into contact with the occupant's knee and receives a load, the restraining teeth provided on the guide portion and the holding piece immediately engage with each other with the tube interposed therebetween. As a result, a large load is applied to the occupant's knee, so that the collision energy absorption performance is reduced.

  An object of the present invention is to obtain an active knee bolster capable of reducing the weight and improving the collision energy absorption performance in consideration of the above facts.

The active knee bolster of the present invention according to claim 1 is an inner cylinder in which a knee protection device is supported at one end;
An outer cylinder fixed to the vehicle body, one end of which supports the inner cylinder movably, and the other end of which is connected to an operating device for moving the inner cylinder;
Disposed between the inner cylinder and the outer cylinder, and when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body, at least one of the inner cylinder and the outer cylinder is A stopper that stops the relative movement between the inner cylinder and the outer cylinder by gradually deforming,
It is characterized by having.

  Therefore, the active knee bolster is fixed to the vehicle body, the inner cylinder with the knee protection device supported at one end, the one end supports the inner cylinder in a movable manner, and the inner cylinder at the other end. Since it can be made into a double structure with the outer cylinder to which the actuating device for moving is connected, the weight can be reduced. In addition, in the state where the inner cylinder moves relative to the outer cylinder by the actuating device and the knee protection device supported by one end of the inner cylinder restrains the occupant's knee, the input load from the occupant's knee When the inner cylinder receives a load greater than or equal to a predetermined value from the rear of the vehicle body to the front of the vehicle body, a stopper disposed between the inner cylinder and the outer cylinder gradually removes at least one of the inner cylinder and the outer cylinder. By deforming, the relative movement between the inner cylinder and the outer cylinder can be gradually stopped. For this reason, the absorption performance of collision energy can be improved.

According to a second aspect of the present invention, in the active knee bolster according to the first aspect of the present invention, the stopper is configured such that the gap between the inner cylinder and the outer cylinder is gradually narrowed along the axial direction of the inner cylinder. And
A ball that is disposed in the inclined portion and deforms at least one of the inner cylinder and the outer cylinder when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body;
It is characterized by being.

  Therefore, in addition to the contents described in claim 1, when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body due to an input load from the occupant's knee, The ball disposed in the inclined portion whose gap between the inner cylinder and the inner cylinder is gradually narrowed gradually deforms at least one of the inner cylinder and the outer cylinder, so that the inner cylinder and the outer cylinder The relative movement of can be stopped gradually. As a result, the collision energy absorption performance can be improved. For this reason, in addition to the content of Claim 1, collision energy absorption performance can be improved with a simple configuration.

  The active knee bolster of the present invention according to claim 1 is fixed to the vehicle body, the inner cylinder having the knee protection device supported at one end, the one end movably supporting the inner cylinder, and the other The outer cylinder, which is connected between the inner cylinder and the outer cylinder, and the inner cylinder receives a load greater than a predetermined value from the rear of the vehicle body to the front of the vehicle body. In this case, since it has a stopper that stops relative movement between the inner cylinder and the outer cylinder by deforming at least one of the inner cylinder and the outer cylinder, the weight can be reduced and the collision energy can be absorbed. It has an excellent effect that the performance can be improved.

  According to a second aspect of the present invention, there is provided the active knee bolster according to the first aspect, wherein the stopper includes an inclined portion in which a gap between the inner cylinder and the outer cylinder is gradually narrowed along the axial direction of the inner cylinder, And a ball that deforms at least one of the inner cylinder and the outer cylinder when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body. In addition to the effects described above, the present invention has an excellent effect that the collision energy absorption performance can be improved with a simple configuration.

  A first embodiment of an active knee bolster according to the present invention will be described with reference to FIGS.

  In the figure, the arrow FR indicates the vehicle body front direction, and the arrow UP indicates the vehicle body upward direction.

  As shown in FIG. 6, the present embodiment includes an acceleration sensor 12 as a collision detection unit that detects deceleration of the vehicle body 10 and detects a collision of the vehicle body 10. Further, the acceleration sensor 12 is disposed on each of the left and right front side members, and the acceleration sensor 12 is connected to a control circuit 14 serving as control means having a microcomputer.

  In the instrument panel 18 of the vehicle body 10, active knee bolsters (lower limb restraining means) 24 are disposed in front of the left and right front seats 20, which are a driver seat and a passenger seat, respectively. The left and right lower limbs (especially knees) 28A of the occupant 28 seated on the front seat 20 are arranged in pairs on the left and right sides.

  The pair of left and right active knee bolsters 24 includes a lower limb restraining portion 30 as a knee protection device for restraining the left and right lower limbs 28A of the occupant 28 seated on the front seat 20 from the front of the vehicle body, and the lower limb restraining portion 30 of the occupant 28. It comprises an actuator 32 for moving to the lower limb restraining position on the lower limb 28A side.

  As shown in FIG. 5, the lower limb restricting portion 30 of the active knee bolster 24 abuts on the lower limb (particularly the knee) 28 </ b> A of the occupant 28 at the restraint position on the rear side of the vehicle body (the position of the two-dot chain line in FIG. 6). At the same time, a part of the general surface 18A of the instrument panel 18 is configured at the storage position (the position indicated by the solid line in FIGS. 5 and 6). The lower limb restraining portion 30 includes a rectangular panel 30A that comes into contact with the lower limb (especially knee) 28A of the occupant 28, and a substrate 30B disposed on the anti-restraining surface (front side of the vehicle body) of the panel 30A. Has been.

  As shown in FIG. 1, a reinforcement bracket 34 is fixed to the instrument panel reinforcement 33 of the vehicle body, and a mounting portion 34 </ b> A of the reinforcement bracket 34 is an inclined portion that extends from the vehicle body front upper side to the vehicle body rear lower side. ing. A plurality of stud bolts 36 are disposed on the attachment portion 34 </ b> A of the reinforcement bracket 34, and these stud bolts 36 pass through the attachment holes 40 of the leg bracket 38 fixed to the actuator 32. . A nut 42 is fastened to the stud bolt 36, and the leg bracket 38 is fixed to the reinforcement bracket 34 by the stud bolt 36 and the nut 42. The leg bracket 38 is formed with a reinforcing bead 38A.

  The actuator 32 has a double pipe structure including an outer cylinder 46 and an inner cylinder 48, and a leg bracket 38 is fixed to the outer peripheral portion of the outer cylinder 46. Further, a lower leg restraining portion 30 is fixed to a rear end portion 48A which is one end portion of the inner cylinder 48 by a bracket 50, and a piston cap is provided to a front end portion 48B which is the other end portion of the inner cylinder 48. 52 is disposed. An O-ring 54 is disposed in the groove 52A formed in the outer peripheral portion of the piston cap 52, and seals the gap between the outer cylinder 46 and the piston cap 52.

  A rear end portion 46A, which is one end portion of the outer cylinder 46, has a reduced diameter, and supports the inner cylinder 48 so as to be movable in the longitudinal direction of the vehicle body (the directions of arrows A and B in FIG. 1). The front end 46B, which is the other end of the outer cylinder 46, is closed by a cylinder cap 56, and one end 58A of the connect pipe 58 passes through the cylinder cap 56. Note that the tip of the end 58 </ b> A of the connect pipe 58 reaches the piston cap 52.

  The other end 58 </ b> B of the connect pipe 58 is connected to a known inflator 60 as an operating device, and the inflator 60 is electrically connected to the control circuit 14.

  As shown in FIG. 5, in this embodiment, gas is supplied from one inflator 60 to the left and right actuators 32, and the left and right connect pipes 58 are connected to the inflator 60.

  The inflator 60 is operated by a squib that is electrically connected to the control circuit 14 (see FIG. 5), and the gas generated from the inflator 60 is supplied to the left and right actuators 32 via the left and right connect pipes 58. When the gas is discharged into the outer cylinder 46, the gas pressure causes the inner cylinder 48 disposed on the axis of the outer cylinder 46 to linearly move in the occupant direction (in the direction of arrow A in FIG. 5), which is the rear of the vehicle body. It has become.

  As shown in FIG. 1, a convex portion 48 </ b> C whose diameter is increased on the outer peripheral side is formed in the vicinity of the front end portion 48 </ b> B of the inner cylinder 48, and the inner cylinder is interposed between the convex portion 48 </ b> C and the piston cap 52. A coil spring 61 wound around the outer periphery of 48 is disposed.

  As shown in FIG. 3, an inclined portion 48 </ b> D constituting a stopper is formed on the front side of the convex portion 48 </ b> C of the inner cylinder 48, and the inclined portion 48 </ b> D is a gap between the inner cylinder 48 and the outer cylinder 46. 62 is gradually narrowed from the front side of the vehicle body toward the rear side of the vehicle body along the direction of the axis 48E of the inner cylinder 48.

  A plurality of balls 64 made of steel balls or the like constituting a stopper are disposed in the gap 62 between the inner cylinder 48 and the outer cylinder 46, and between the balls 64 and the coil spring 61. A retainer 66 is provided.

  Therefore, the ball 64 is pressed against the inclined portion 48D by the coil spring 61 as an urging means via the retainer 66, and does not play.

  The plate thickness M 1 of the inner cylinder 48 is thicker than the plate thickness M 2 of the outer cylinder 46, and the outer cylinder 46 is more easily deformed than the inner cylinder 48. Further, the outer cylinder 46 may be more easily deformed than the inner cylinder 48 by making the strength of the inclined portion 48D of the inner cylinder 48 higher than the strength of the outer cylinder 46 by heat treatment or the like.

  As shown in FIG. 4, the retainer 66 has a ring shape made of metal, rubber or the like, and a wall portion 66B is formed on the vehicle body rear side surface 66A toward the vehicle body rear side. The wall portions 66B are formed with semicircular concave portions 66C at predetermined intervals along the circumferential direction, and one ball 64 is held in each of the concave portions 66C.

  Therefore, as shown in FIG. 3, when the inner cylinder 48 moves to the rear of the vehicle body with respect to the outer cylinder 46, the convex portion 48 </ b> C of the inner cylinder 48 becomes a rear end portion 46 </ b> A of the outer cylinder 46 whose diameter has been reduced. The ball 64 moves together with the retainer 66 to the rear of the vehicle body by the urging force of the coil spring 61 and is held in the gap between the inclined portion 48D of the inner cylinder 48 and the outer cylinder 46. It has become.

  When the inner cylinder 48 receives a load of a predetermined value or more in front of the vehicle body (in the direction of arrow B in FIG. 3), which is opposite to the moving direction, the plurality of balls 64 are moved in the outer circumferential direction (FIG. 3) by the inclined portion 48D. Are gradually pushed out in the direction of arrow C), and indentations are formed in the outer cylinder 46, which is weaker than the inner cylinder 48, and the outer cylinder 46 gradually expands in diameter, so that a lot of collision energy can be absorbed. ing.

  In the present embodiment, as shown in FIG. 6, the airbag device for the passenger seat and the driver seat are disposed on the upper portion 18 </ b> B of the instrument panel 18 and the steering wheel 68. The airbag bag body 70 (only the airbag for the driver's seat is shown in FIG. 6) is inflated and deployed toward the upper body 28B of the occupant 28 seated on the front seat 20. Moreover, the code | symbol 72 of FIG. 6 has shown the seatbelt.

  Next, the operation of this embodiment will be described.

  In this embodiment, the left and right actuators 32 of the active knee bolster 24 are fixed to the inner cylinder 48 in which the lower limb restraint portion 30 is supported by the rear end portion 48A and the instrument panel reinforcement 33 of the vehicle body, and the rear end portion 46A is Since the cylinder 48 is supported so as to be movable and the outer cylinder 46 is connected to the front end portion 46B of the inflator 60 that moves the inner cylinder 48, the weight can be reduced.

  Further, when the vehicle body 10 collides, the control circuit 14 first determines whether or not the vehicle body 10 has collided based on input signals from the acceleration sensors 12 respectively disposed on the left and right front side members. .

  When it is determined that the vehicle body 10 has collided, the control circuit 14 operates the inflator 60 of the active knee bolster 24. As a result, when the gas generated from the inflator 60 is released into the outer cylinders 46 of the left and right actuators 32 via the left and right connect pipes 58, the inner cylinder 48 disposed on the axis of the outer cylinder 46 is in the occupant direction. Move straight (in the direction of arrow A in FIG. 1).

  As a result, the lower limb restraining portions 30 fixed to the rear end portions 48A of the left and right inner cylinders 48 move linearly in the occupant direction (the direction of arrow A in FIG. 2), and as shown by the two-dot chain line in FIG. The lower limb restraining portion 30 contacts the left and right lower limbs 28A of the occupant 28 seated on the front seat 20 from the front of the vehicle body. Therefore, the left and right lower limbs 28 </ b> A of the occupant 28 can be restrained from the front of the vehicle body by the left and right lower limb restraining portions 30.

  Further, when the inner cylinder 48 moves to the rear of the vehicle body with respect to the outer cylinder 46, as shown in FIG. 3, the convex portion 48C of the inner cylinder 48 becomes a rear end portion 46A of the outer cylinder 46 whose diameter has been reduced. The ball 64 moves to the rear of the vehicle body together with the retainer 66 by the urging force of the coil spring 61 and is held in the gap between the inclined portion 48D of the inner cylinder 48 and the outer cylinder 46.

  As a result, the left and right lower limb restraint portions 30 are pressed by the left and right lower limbs 28A of the occupant 28, and the inner cylinder 48 moves from the lower limbs 28A toward the front of the vehicle body (in the direction of arrow B in FIG. 3) via the lower limb restraint portions 30. When a load of a predetermined value or more is received, the plurality of balls 64 are gradually pushed out in the outer peripheral direction (in the direction of arrow C in FIG. 3) by the inclined portion 48D, and the outer cylinder 46 having a lower strength than the inner cylinder 48, As shown by a two-dot chain line in FIG. 3, an indentation is formed, and the outer cylinder 46 gradually expands in diameter, so that a lot of collision energy can be absorbed.

  Therefore, the movement of the inner cylinder 48 toward the front of the vehicle body (in the direction of arrow B in FIG. 3) can be stopped gradually, and the impact energy absorption performance can be improved.

  Further, in the present embodiment, when a load of a predetermined value or more is received from the lower limb 28A toward the front of the vehicle body (in the direction of arrow B in FIG. 3) via the lower limb restraining portion 30, the plurality of balls 64 are caused by the inclined portion 48D. Since the outer cylinder 46 is gradually extruded in the outer peripheral direction (the direction of arrow C in FIG. 3) and the strength of the outer cylinder 46 is weaker than that of the inner cylinder 48 as shown by a two-dot chain line in FIG. With a simple configuration, the collision energy absorption performance can be improved.

  In the present embodiment, the amount of energy absorption can be easily adjusted by appropriately changing the thickness or material of the inner cylinder 48 or the outer cylinder 46, the diameter or number of the balls 64, and the like.

  Further, the retainer 66 and the coil spring 61 may be integrated with an elastic body.

  Moreover, it is good also as a structure which abbreviate | omitted the leg bracket 38 by fixing the outer cylinder 46 to the reinforcement bracket 34 directly.

  Next, a second embodiment of the active knee bolster according to the present invention will be described with reference to FIGS.

  In addition, the same member as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description.

  As shown in FIG. 7, the actuator 32 of this embodiment includes an outer cylinder 76 and an inner cylinder 78, and has a double pipe structure. The lower leg restraining portion 30 is fixed to the rear end portion 78A which is one end portion of the inner cylinder 78 by the bracket 50, and the piston cap 52 is attached to the front end portion 78B which is the other end portion of the inner cylinder 78. It is arranged. An O-ring 54 is disposed in the groove 52 </ b> A formed in the outer peripheral portion of the piston cap 52, and seals the gap between the outer cylinder 76 and the piston cap 52.

  A rear end portion 76A, which is one end portion of the outer cylinder 76, has an enlarged diameter, and a cylinder cap 80 disposed at the opening end portion moves the inner cylinder 78 in the vehicle longitudinal direction (the direction of arrow A and arrow B in FIG. 7). It is supported to be movable in the direction). The front end portion 76B, which is the other end portion of the outer cylinder 76, is closed by a wall 76C, and one end portion 58A of the connect pipe 58 passes through the wall 76C. Note that the tip of one end 58 </ b> A of the connect pipe 58 reaches the piston cap 52.

  The other end 58 </ b> B of the connect pipe 58 is connected to a known inflator 60 as a gas generator, and the inflator 60 is electrically connected to the control circuit 14.

  The inflator 60 is operated by a squib connected to the control circuit 14 (see FIG. 5), and the gas generated from the inflator 60 is discharged into the outer cylinders 76 of the left and right actuators 32 via the left and right connect pipes 58. Then, the inner cylinder 78 disposed on the axis of the outer cylinder 76 moves linearly in the occupant direction (arrow A direction in FIG. 8).

  A cylindrical lock bracket 82 is disposed in the inner peripheral portion of the inner cylinder 78 in the vicinity of the rear end portion 78A, and a lock cap 84 is provided in the opening of the rear end portion 82A of the vehicle body of the lock bracket 82. The rear end opening of the lock bracket 82 is fixed by caulking. A coil spring 61 wound around the outer peripheral portion of the inner cylinder 78 is disposed between the front end portion 82 </ b> B of the lock bracket 82 and the lock cap 84.

  As shown in FIG. 9, an inclined portion 82 </ b> C is formed in the vicinity of the front end portion 82 </ b> B of the lock bracket 82, and the inclined portion 82 </ b> C forms a gap 86 between the inner cylinder 78 and the lock bracket 82. The width gradually decreases from the rear side of the vehicle body toward the front side of the vehicle body along the direction of the axis 78C.

  A plurality of balls 64 made of steel balls or the like constituting a stopper are disposed in the gap 86 between the inner cylinder 78 and the lock bracket 82, and between the balls 64 and the coil spring 61. A retainer 66 is provided. Note that the front-rear direction of the retainer 66 is opposite to that of the first embodiment.

  As shown in FIG. 10, grooves 88 are formed in the inner peripheral portion 82 </ b> D of the lock bracket 82 at a predetermined interval along the circumferential direction along the longitudinal direction of the vehicle body. One groove 88 is formed along each groove 88. The ball 64 moves in the longitudinal direction of the vehicle body.

  The plate thickness M3 of the lock bracket 82 is thicker than the plate thickness M4 of the inner cylinder 78, and the inner cylinder 78 is more easily deformed than the lock bracket 82. Further, the inner cylinder 78 may be more easily deformed than the lock bracket 82 by making the strength of the lock bracket 82 higher than that of the inner cylinder 78 by heat treatment or the like.

  Therefore, as shown in FIG. 11, when the inner cylinder 78 moves to the rear of the vehicle body with respect to the outer cylinder 76, the outer peripheral portion 52 </ b> B of the piston cap 52 contacts the front end portion 82 </ b> B of the lock bracket 82. 78 stops and the urging force of the coil spring 61 moves the ball 64 together with the retainer 66 to the front of the vehicle body and is held in the gap between the inclined portion 82C of the lock bracket 82 and the inner cylinder 78. ing.

  In addition, when the inner cylinder 78 receives a load of a predetermined value or more in front of the vehicle body (in the direction of arrow B in FIG. 11), which is in the direction opposite to the moving direction, the plurality of balls 64 are moved in the inner circumferential direction (see FIG. 11 (in the direction of arrow D), the inner cylinder 78 is weaker than the lock bracket 82, and an indentation is formed as shown by a two-dot chain line in FIG. Therefore, a lot of collision energy can be absorbed.

  Next, the operation of this embodiment will be described.

  In this embodiment, the left and right actuators 32 of the active knee bolster 24 are fixed to the inner cylinder 78 in which the lower limb restraining portion 30 is supported by the rear end portion 78A and the instrument panel reinforcement 33 of the vehicle body, and the rear end portion 76A is Since the cylinder 78 is supported so as to be movable and the outer cylinder 76 is connected to the front end portion 76B of the inflator 60 that moves the inner cylinder 78, the weight can be reduced.

  Similarly to the first embodiment, when the vehicle body 10 collides, the control circuit 14 first determines that the vehicle body 10 is based on input signals from the acceleration sensors 12 respectively disposed on the left and right front side members. Determine if there is a collision.

  When it is determined that the vehicle body 10 has collided, the control circuit 14 operates the inflator 60 of the active knee bolster 24. As a result, when the gas generated from the inflator 60 is released into the outer cylinders 76 of the left and right actuators 32 via the left and right connect pipes 58, the inner cylinder 78 disposed on the shaft core of the outer cylinder 76 is occupant direction. Move straight (in the direction of arrow A in FIG. 8).

  As a result, the lower limb restraining portions 30 fixed to the rear end portions 78A of the left and right inner cylinders 78 linearly move in the occupant direction (the direction of arrow A in FIG. 8), and as shown by the two-dot chain line in FIG. The left and right lower limbs 28A of the occupant 28 seated on the seat 20 abut from the front of the vehicle. For this reason, the left and right lower limb restraining portions 30 restrain the left and right lower limbs 28A of the occupant 28 from the front of the vehicle body.

  When the inner cylinder 78 moves rearward of the outer cylinder 76 with respect to the outer cylinder 76, the outer peripheral portion 52B of the piston cap 52 contacts the front end portion 82B of the lock bracket 82 as shown in FIG. 78 stops and the urging force of the coil spring 61 moves the ball 64 together with the retainer 66 to the front of the vehicle body with respect to the inner cylinder 78, and into the gap between the inclined portion 82 </ b> C of the lock bracket 82 and the inner cylinder 78. Retained.

  As a result, the left and right lower limb restraint portions 30 and the left and right lower limbs 28A of the occupant 28 come into contact with each other, and the inner cylinder 78 is directed from the lower limbs 28A to the front of the vehicle body (in the direction of arrow B in FIG. 11) via the lower limb restraint portions 30. When a load greater than or equal to a predetermined value is received, the plurality of balls 64 are gradually pushed out in the inner circumferential direction (in the direction of arrow D in FIG. 11) by the inclined portion 82C, and the inner cylinder 78 is weaker than the lock bracket 82. In addition, as shown by a two-dot chain line in FIG. 11, a large amount of collision energy can be absorbed by forming an indentation and gradually reducing the diameter.

  For this reason, the movement of the inner cylinder 78 toward the front of the vehicle body (in the direction of arrow B in FIG. 11) can be gradually stopped, and the collision energy absorption performance can be improved.

  Further, in the present embodiment, when a load of a predetermined value or more is received from the lower limbs 28A toward the front of the vehicle body (in the direction of arrow B in FIG. 11) via the lower limb restraining portion 30, the plurality of balls 64 are moved by the inclined portions 82C. The inner cylinder 78, which is gradually pushed out in the inner circumferential direction (the direction of arrow D in FIG. 11) and is thinner than the lock bracket 82, is configured to gradually reduce the diameter as shown by a two-dot chain line in FIG. The impact energy absorption performance can be improved with a simple configuration.

  In the present embodiment, since the grooves 88 are formed along the vehicle body front-rear direction at predetermined intervals along the circumferential direction in the inner peripheral portion 82D of the lock bracket 82, the balls 64 are formed depending on the position and number of the grooves 88. It can be efficiently placed in the optimal place.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, in the above embodiment, the acceleration sensor 12 is used to determine the collision, but instead of this, by using a camera, a radar, or the like indicated by reference numeral 90 in FIG. It is good also as a structure which senses, ie, performs collision prediction and operates an active knee bolster.

  In the above embodiment, the active knee bolster of the present invention is applied to the front seats (driver's seat and front passenger seat). However, the active knee bolster of the present invention can also be applied to a seat other than the front seat such as a rear seat.

It is a sectional side view which shows the storing position of the active knee bolster which concerns on 1st Embodiment of this invention. It is a sectional side view which shows the restraint position of the active knee bolster which concerns on 1st Embodiment of this invention. It is a sectional side view which shows the one part restraint position of the active knee bolster which concerns on 1st Embodiment of this invention. It is the perspective view seen from the vehicle body slanting back which shows a part of active knee bolster which concerns on 1st Embodiment of this invention. 1 is a schematic plan view showing an active knee bolster according to a first embodiment of the present invention. It is a schematic sectional side view which shows the compartment front part to which the active knee bolster which concerns on 1st Embodiment of this invention was applied. It is a sectional side view which shows the storing position of the active knee bolster which concerns on 2nd Embodiment of this invention. It is a sectional side view which shows the restraint position of the active knee bolster which concerns on 2nd Embodiment of this invention. It is a sectional side view which shows the storing position of a part of active knee bolster which concerns on 2nd Embodiment of this invention. FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. 9. It is a sectional side view which shows the one part restraint position of the active knee bolster which concerns on 2nd Embodiment of this invention.

Explanation of symbols

24 Active knee bolster 30 Lower limb restraint part (knee protector)
32 Actuator 46 Outer cylinder 46A Outer cylinder rear end 46B Outer cylinder front end 48 Inner cylinder 48A Inner cylinder rear end 48B Inner cylinder front end 48D Inner cylinder inclined part (stopper)
52 Piston cap 56 Cylinder cap 58 Connect pipe 60 Inflator (actuator)
61 Coil spring 64 Ball (stopper)
66 Retainer 76 Outer cylinder 76A Outer cylinder rear end 76B Outer cylinder front end 78 Inner cylinder 78A Inner cylinder rear end 78B Inner cylinder front end 80 Cylinder cap 82 Lock bracket 82C Inclined portion of stopper (stopper)
84 Lock cap

Claims (2)

An inner cylinder with a knee protection device supported at one end;
An outer cylinder fixed to the vehicle body, one end of which supports the inner cylinder movably, and the other end of which is connected to an operating device for moving the inner cylinder;
Disposed between the inner cylinder and the outer cylinder, and when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body, at least one of the inner cylinder and the outer cylinder is A stopper that stops relative movement between the inner cylinder and the outer cylinder by deforming;
An active knee bolster characterized by comprising: The stopper has an inclined portion that gradually narrows the gap between the inner cylinder and the outer cylinder along the axial direction of the inner cylinder,
A ball that is disposed in the inclined portion and deforms at least one of the inner cylinder and the outer cylinder when the inner cylinder receives a load of a predetermined value or more from the rear of the vehicle body to the front of the vehicle body;
The active knee bolster according to claim 1, wherein:

Images