Knee-protecting airbag device

1. A knee-protecting airbag device mountable on a vehicle, comprising:

a case provided with an airbag emergence opening at a lower end region thereof;

an inflatable airbag that is housed in and mounted on the case in a folded-up configuration, the airbag including:

a vehicle body side panel deployable towards a vehicle body structure;

an occupant side panel deployable towards a seat of the vehicle;

a mounting inflatable region that is located in a lower end region of the airbag as deployed and is secured to the case;

a knee-protecting region that is deployable in such a manner as to extend rearwardly and upwardly from the mounting inflatable region for protecting knees of a vehicle occupant; and

an auxiliary inflatable region on the occupant side panel at a rear of the mounting inflatable region of the airbag as deployed, wherein the auxiliary inflatable region is deployable at the rear of the mounting inflatable region and in a vicinity of the case so as to protrude downward;

an inflator for feeding an inflation gas to the airbag, the inflator being generally cylindrical in outer contour and including a mounting means with which the inflator and airbag are mounted on the case;

a first tether that is disposed inside the mounting inflatable region of the airbag and joins the vehicle body side panel and the occupant side panel for regulating a clearance between the vehicle body side panel and the occupant side panel at airbag deployment,

wherein the first tether is located proximate to the inflator; and

a plurality of partitioning tethers arranged at a front and a rear of the auxiliary inflatable region, the plurality of partitioning tethers partition the mounting inflatable region, the auxiliary inflatable region, and the knee-protecting region.

2. The knee-protecting airbag device according to claim 1 , wherein the first tether is deployable in front of the inflator.

3. The knee-protecting airbag device according to claim 2 , wherein:

the first tether is formed into a band deployable generally along a left and right direction; and

a first end in a width direction of the first tether is joined to the vehicle body side panel generally entirely while a second end in the width direction of the first tether is joined to the occupant side panel generally entirely, such that the first tether is disposed over a generally entire area in a left and right direction of the mounting inflatable region.

4. The knee-protecting airbag device according to claim 1 , wherein the first tether is deployable within an area immediately below the case in a front and rear direction.

5. The knee-protecting airbag device according to claim 1 , wherein the first tether is brought into contact with the inflator at airbag deployment.

6. The knee-protecting airbag device according to claim 5 , wherein the first tether is deployable at a rear of the inflator.

7. The knee-protecting airbag device according to claim 6 , wherein:

the first tether is formed into a band deployable generally along a left and right direction; and

a first end in a width direction of the first tether is joined to the vehicle body side panel generally entirely while a second end in the width direction of the first tether is joined to the occupant side panel generally entirely, such that the first tether is disposed over a generally entire area in a left and right direction of the mounting inflatable region.

8. The knee-protecting airbag device according to claim 1 , wherein

the first tether is disposed over a generally entire area in a left and right direction of the mounting inflatable region,

the first tether includes a gas communication hole that provides gas communication, and

the inflator is provided with a plurality of gas discharge ports on a first end of an axial direction, the gas discharge ports being located in a region coincided with the gas communication hole in the left and right direction.