JP4091461B2

JP4091461B2 - Rear seat airbag device

Info

Publication number: JP4091461B2
Application number: JP2003089167A
Authority: JP
Inventors: 裕之小林; 敏男行田; 武明加藤; 誠関塚; 成和今中
Original assignee: Tokai Rika Co Ltd; Toyoda Gosei Co Ltd
Current assignee: Tokai Rika Co Ltd; Toyoda Gosei Co Ltd
Priority date: 2003-03-27
Filing date: 2003-03-27
Publication date: 2008-05-28
Anticipated expiration: 2023-03-27
Also published as: JP2004291888A

Description

【０００１】
【発明の属する技術分野】
本発明は、衝突等による衝撃が車両に加わったときに、前席と後席との間において展開膨張するエアバッグを備えた後席用エアバッグ装置に関するものである。なお、本明細書において、「前席」とは、後方に他の席がある席を意味し、運転席及び助手席に限らない。また、「後席」とは、「前席」の後にある席を意味する。
【０００２】
【従来の技術】
従来のこの種の後席用エアバッグ装置としては、前席のシートベースフレームに設けられたエアバッグモジュールから、後席乗員に向かってエアバッグが展開するものがある。このエアバッグは、前席背もたれ部の後方において背もたれ部の背面に沿って上方に展開し、次いで、後席乗員の胸部あるいは頭部の前方で展開する（特許文献１参照。）。
【０００３】
【特許文献１】
特表２００２−５４２１００号公報
【０００４】
【発明が解決しようとする課題】
しかしながら、上記特許文献１に記載のエアバッグ装置では、前席と後席乗員との位置間隔に関係なく、エアバッグを一定の大きさまで展開膨張させているだけである。このため、前席の前後位置や、後席乗員の体格等の違い等によってエアバッグと後席乗員との位置関係が変化したときに、後席乗員に対する保護機能が低下する可能性がある。
【０００５】
本発明は、上記課題を解決するためになされたものであって、その目的は、前席と後席乗員との位置関係が変化しても、後席乗員に対する保護機能が低下し難い後席用エアバッグ装置を提供することにある。
【０００６】
【課題を解決するための手段】
以下、上記目的を達成するための手段及びその作用効果について記載する。
（１）請求項１に記載の発明は、前席から前席と後席との間に向けて展開膨張するエアバッグと、このエアバッグにガスを供給するインフレータとを備えた後席用エアバッグ装置において、後席乗員の着座状態と前席の前後調節位置及び前席の背もたれ部の倒れ角及び後席の前後調節位置及び後席背もたれ部の倒れ角の少なくとも一つとを検出し、この検出結果に基づいて前席の背もたれ部と後席乗員との間隔の推定値を求める検出手段と、予め重ね合わせられた状態でエアバッグに設けられて、インフレータからガスが供給されたときのガスの圧力に応じて前記予め重ね合わせられた状態とこの状態から展開した状態とのいずれかに維持されるものであって、前記予め重ね合わせられた状態と前記展開した状態とのいずれにあるかの違いによりエアバッグの展開膨張時の厚さを切り換える規制手段と、前記間隔の推定値に基づいてエアバッグの作動の要否を判定し、この判定を通じて作動させる必要がある旨の結果が得られたときにエアバッグを展開膨張させるとともに前記間隔の推定値に基づいて展開膨張時の厚さを調節し、この厚さの調節として、インフレータからのガスの発生量を制御してエアバッグへのガスの供給量を調節し、これにより前記規制手段の状態を前記予め重ね合わせられた状態と前記展開した状態とのいずれかに切り換える調節手段とを備えることを要旨としている。
【０００７】
上記発明によれば、前席と後席乗員との位置関係が変化しても、後席乗員に対する保護機能が低下し難いように、前席と後席との間でエアバッグが展開膨張する形態を調節することができる。また、ガス量を変更するだけの簡単な操作によってエアバッグが展開膨張する厚さが調節できるので、容易に実施できる。また、簡単に検出可能な各検出量から前席と後席乗員との間隔を推定することができるので、より高度で複雑な検出手段を用いる必要がなく、容易に実施できる。
【０００８】
（２）請求項２に記載の発明は、請求項１に記載の後席用エアバッグ装置において、前記調節手段は、前記間隔の推定値に基づくエアバッグの作動の要否の判定に加えて、前記後席乗員の着座状態が正しい状態にあるか否かによるエアバッグの作動の要否の判定を行い、これら判定のそれぞれによりエアバッグを作動させる必要がある旨の結果が得られたときにエアバッグを展開膨張させることを要旨としている。
【００１１】
（３）請求項３に記載の発明は、請求項１または２に記載の後席用エアバッグ装置において、前記規制手段は、複数の段階に設定されたガスの供給量に応じて破断する破断部が設けられるものであり、ガスが供給されたときに前記破断部が破断した状態にあるか破断していない状態にあるかの違いにより前記予め重ね合わせられた状態と前記展開した状態とのいずれかに維持され、これによりエアバッグの展開膨張時の厚さを切り換えるものであることを要旨としている。
【００１２】
上記発明によれば、エアバッグが展開膨張する厚さが異なってもその内圧を所定値以上確保することができるので、厚さを切り換えることによるエアバッグの保護機能の低下を防止することができる。
【００１３】
（４）請求項４に記載の発明は、請求項１〜３のいずれか一項に記載の後席用エアバッグ装置において、前記規制手段は、予め重ね合わせられた状態でエアバッグ内部に設けられるテザーであって、ガスが供給されたときに当該テザーが予め重ね合わせられた状態にあるかこの状態から展開した状態にあるかの違いによりエアバッグの展開膨張時の厚さを切り換えるものであることを要旨としている。
【００１４】
（５）請求項５に記載の発明は、請求項１〜３のいずれか一項に記載の後席用エアバッグ装置において、前記規制手段は、エアバッグの外周の一部が予め重ね合わせられた部位であって、ガスが供給されたときに当該部位が予め重ね合わせられた状態にあるかこの状態から展開した状態にあるかの違いによりエアバッグの展開膨張時の厚さを切り換えるものであることを要旨としている。
【００１５】
上記（４）または（５）に記載の発明によれば、エアバッグが展開膨張する厚さを簡単な構成によって切り換えることができる。
【００１６】
（６）請求項６に記載の発明は、請求項１〜５のいずれか一項に記載の後席用エアバッグ装置において、前記エアバッグは、前席の座部または座部の下側に収容されるものであり、前席の背もたれ部の背面に沿う態様で上方に向けて展開膨張するものであることを要旨としている。
【００１７】
上記発明によれば、前席と後席乗員との位置関係が変化しても後席乗員の膝下に干渉することなく展開膨張し、膝及び膝下を保護することができる。
【００１８】
（７）請求項７に記載の発明は、請求項１〜６のいずれか一項に記載の後席用エアバッグ装置において、前記エアバッグは、後席乗員の膝及び膝下に対応して扁平状に展開膨張するものであることを要旨としている。
【００１９】
上記発明によれば、前席と後席乗員の膝及び膝下との位置関係が変化しても、後席乗員の膝及び膝下に対する保護機能が低下し難い。
【００２０】
【発明の実施の形態】
以下、本発明を具体化した一実施形態を図１〜図８及び図１０に従って説明する。
【００２１】
図２に示すように、車両における前席１０の座部１１の下面には、後席１２に着座する後席乗員Ｍを保護するためのエアバッグモジュール１３が固定されている。
【００２２】
図３及び図４（ａ）に示すように、エアバッグモジュール１３は、座部１１に固定されるケース１４、ケース１４内に収容された一対のインフレータ１５ａ，１５ｂ、ケース１４に収容されるとともにインフレータ１５ａ，１５ｂが供給するガスによって展開膨張するエアバッグ１６を備えている。
【００２３】
図４（ｂ）に示すように、ケース１４は、後席１２側に向いた開口部１７を有し、この開口部１７から折り畳んだ状態のエアバッグ１６を後席１２側に展開させるようになっている。開口部１７は、エアバッグ１６の展開時にティアライン１８ａ，１８ｂで切り離されて上下に開く上側蓋部１９ａ及び下側蓋部１９ｂによって閉塞されている。
【００２４】
図５、図６及び図７に示すように、エアバッグ１６は、前席１０と後席１２との間で、前席１０の背もたれ部２０の背面２０ａに沿って略上方に展開膨張するようになっている。また、エアバッグ１６は、扁平状をなすように、しかも、前後方向視で略四角形に展開膨張するようになっている。
【００２５】
エアバッグ１６の内部には、前側の基布１６ａと後側の基布１６ｂとを連結するテザー２１ａ，２１ｂが設けられている。エアバッグ１６は、テザー２１ａ，２１ｂによって展開膨張する形状が制限されて厚さが切り換わる。図８に示すように、テザー２１ａ，２１ｂの中間部には、それぞれ破断部としてのティアシーム部２２ａ，２２ｂによって重合部２３ａ，２３ｂが設けられている。なお、ここで「破断」とは、ティアシーム部２２ａ，２２ｂのシームが破断されて、重合部２３ａ，２３ｂが延びることをいう。
【００２６】
重合部２３ａ，２３ｂは、第１インフレータ１５ａのみからガスが供給されたときには、図６に示すように、そのティアシーム部２２ａ，２２ｂが破断せず、重合状態を維持する。このため、エアバッグ１６は、薄く展開膨張し、展開膨張後の容積が制限されることで所定値以上の内圧となる。また、重合部２３ａ，２３ｂは、第１インフレータ１５ａに加えて第２インフレータ１５ｂからガスが供給されて内圧が増大したときには、図７に示すように、ティアシーム部２２ａ，２２ｂが破断して重合状態から展開する。このため、エアバッグ１６はより厚く展開膨張した状態で所定値以上の内圧となる。
【００２７】
図１に示すように、後席用エアバッグ装置３０は、エアバッグモジュール１３に加え、シートベルトセンサ３１、前席位置センサ３２、前席倒れ角センサ３３、後席位置センサ３４、後席倒れ角センサ３５、後席着座センサ３６及びコントローラ３７によって構成される。本実施形態では、前席位置センサ３２、前席倒れ角センサ３３、後席位置センサ３４、後席倒れ角センサ３５、後席着座センサ３６及びコントローラ３７が検出手段を構成し、第１インフレータ１５ａ、第２インフレータ１５ｂ、テザー２１ａ，２１ｂ及びコントローラ３７が調節手段を構成する。
【００２８】
シートベルトセンサ３１は、図示しない後席シートベルトのバックルに付設され、後席乗員Ｍがシートベルトをしているか否かを検出する。
前席位置センサ３２、前席倒れ角センサ３３、後席位置センサ３４、後席倒れ角センサ３５、後席着座センサ３６は、背もたれ部２０と後席乗員Ｍの膝Ｋｎとの位置関係を検出するための各種情報を検出する。前席位置センサ３２は、前席１０を前後に移動させる駆動モータ（図示しない）の回転量から前席１０の前後位置を検出し、前席倒れ角センサ３３は、背もたれ部２０を前後に傾動させる駆動モータ（図示しない）の回転量から背もたれ部２０の倒れ角を検出する。後席位置センサ３４は、後席１２を前後に移動させる駆動モータ（図示しない）の回転量から後席１２の前後位置を検出し、後席倒れ角センサ３５は、後席１２の背もたれ部２４を前後に傾動させる駆動モータ（図示しない）の回転量から背もたれ部２４の倒れ角を検出する。
【００２９】
後席着座センサ３６は、例えば後席１２の座部２５の前部、中央部及び後部にそれぞれ設けられている。各後席着座センサ３６は、後席乗員Ｍの着座状態、すなわち、後席乗員Ｍが座部２５の正しい位置に着座しているか否かを推定可能な、座部２５の前部、中央部及び後部における着座状態を検出する。後席乗員Ｍが座部２５の正しい位置に着座している状態は、前部、中央部及び後部の各後席着座センサ３６がいずれも後席乗員Ｍの着座を検出する。一方、例えば、後席乗員Ｍである子供が座部２５から立ち上がっているときには、いずれの後席着座センサ３６も後席乗員Ｍの着座を検出しない。また、後席乗員Ｍが座部２５に浅く腰掛けているときには、前部の後席着座センサ３６のみが着座を検出する。
【００３０】
図１０に示すプログラムを格納したコントローラ３７は、図示しない衝撃検出器から入力する衝撃検出結果を起点とした後述のプログラムの動作に基づき、エアバッグ１６を作動させるか否かを決定する。すなわち、コントローラ３７は、エアバッグ１６を作動させることを決定したときには、各センサ３２〜３６から入力した検出結果に基づき、以下に説明するエアバッグ１６の展開制御を行う。
【００３１】
図１０に示すように、コントローラ３７は、先ず、ステップ（以下、Ｓと略記する。）１００で、衝撃検出器から入力した衝撃検出結果から、エアバッグ１６を作動させるべきか否かを判定する。そして、エアバッグ１６を作動させるべき状態でないと判断したときには、本処理を終了する。
【００３２】
一方、Ｓ１００で、エアバッグ１６を作動させるべきであると判断したときには、次にＳ１１０で、シートベルトセンサ３１から入力した検出結果に基づき、後席乗員Ｍがシートベルトをしているか否かを判断する。そして、シートベルトをしていないと判断したときには、本処理を終了する。
【００３３】
Ｓ１１０で、後席乗員Ｍがシートベルトをしていると判断したときには、次に、Ｓ１２０で、各後席着座センサ３６の検出結果から、後席乗員Ｍの座部２５への着座状態が正しいか否か判断する。そして、後席乗員Ｍの着座状態が正しくなかったときには、エアバッグ１６を作動させることなく本処理を終了する。
【００３４】
一方、Ｓ１２０で、後席乗員Ｍの着座状態が正しかったときには、次にＳ１３０を実行する。
Ｓ１３０では、各センサ３２〜３６から入力した検出結果から、前席１０の背もたれ部２０の背面２０ａと後席乗員Ｍの膝Ｋｎとの間隔推定値Ｇを求める。この間隔推定値Ｇは、背もたれ部２０の背面２０ａの前後及び上下方向における位置と、後席乗員Ｍの膝Ｋｎの同位置とから求められる。なお、背もたれ部２０の背面２０ａの位置は、前席１０の前後位置、背もたれ部２０の倒れ角から求められる。後席乗員Ｍの膝Ｋｎの位置は、後席１２の前後位置、背もたれ部２４の倒れ角、後席乗員Ｍの着座状態から求められる。
【００３５】
Ｓ１３０を実行すると、次にＳ１４０で、間隔推定値Ｇが、予め設定されている第１間隔判定値Ｇ０以上であるか否かを判定することにより、背もたれ部２０の背面２０ａと後席乗員Ｍの膝Ｋｎとが、エアバッグ１６によって効果的に保護できない程度まで近づきすぎているか否かを判定する。そして、間隔推定値Ｇが第１間隔判定値Ｇ０未満であったときには、背もたれ部２０と膝Ｋｎとが近づき過ぎていると判断し、エアバッグ１６を作動させることなく本処理を終了する。
【００３６】
一方、Ｓ１４０で、間隔推定値Ｇが第１間隔判定値Ｇ０以上であったときには、背もたれ部２０と膝Ｋｎとが近づき過ぎていないと判断し、次にＳ１５０を実行する。
【００３７】
Ｓ１５０では、間隔推定値Ｇが、予め設定されている第２間隔判定値Ｇ１以上であるか否かを判定することにより、エアバッグ１６を展開膨張させる大きさを判断する。Ｓ１５０で、間隔推定値Ｇが第２間隔判定値Ｇ１未満であったときには、エアバッグ１６を薄く展開膨張させた方が適切であると判断し、次にＳ１６０で、第１インフレータ１５ａのみを作動させた後に、本処理を終了する。
【００３８】
一方、Ｓ１５０で、間隔推定値Ｇが第２間隔判定値Ｇ１以上であったときには、エアバッグ１６を大きく展開膨張させた方が適切であると判断し、次にＳ１７０で、第１インフレータ１５ａ及び第２インフレータ１５ｂを共に作動させた後に、本処理を終了する。
【００３９】
次に、以上のように構成された本実施形態の作用について説明する。
後席乗員Ｍがシートベルトを装着していないときや、着座状態が正しくないときには、エアバッグ１６を作動させるべき衝撃が車両に加わってもコントローラ３７はエアバッグ１６を作動させない。従って、車両に衝撃が加わっても、エアバッグ１６を作動させることが適切でないときにはその作動が停止される。
【００４０】
また、前席１０の前後位置が後席１２寄りに調節されていたり、背もたれ部２０が大きく後側に倒されていたりすると、背もたれ部２０の背面２０ａと、後席乗員Ｍの膝Ｋｎとの間隔が相対的に小さくなる。この状態で車両に衝撃が加わったとき、コントローラ３７は第１インフレータ１５ａのみを作動させる。このため、エアバッグ１６は、背もたれ部２０と後席乗員Ｍの膝下との間の比較的狭い空間において背もたれ部２０の背面２０ａに沿って上方に展開膨張し、扁平状に薄く膨らむ。従って、エアバッグ１６は、背もたれ部２０と後席乗員Ｍの膝Ｋｎとの間隔が狭いときにも、後席乗員Ｍの膝下に干渉することなく展開膨張し、背もたれ部２０に近い位置にある後席乗員Ｍの膝Ｋｎ及び膝下を保護する。
【００４１】
一方、前席１０の前後位置が後席１２から離れて調節されていたり、背もたれ部２０が起こされていたりすると、背もたれ部２０の背面２０ａと、後席乗員Ｍの膝Ｋｎとの間隔が相対的に大きくなる。この状態で車両に衝撃が加わったとき、コントローラ３７は第１インフレータ１５ａ及び第２インフレータ１５ｂを共に作動させる。このため、エアバッグ１６は、背もたれ部２０と後席乗員Ｍの膝下との比較的広い空間において背もたれ部２０の背面２０ａに沿って上方に展開膨張し、厚く膨らむ。従って、エアバッグ１６は、背もたれ部２０と膝Ｋｎとの間隔が広いときにも、後席乗員Ｍの膝下に干渉することなく展開膨張し、背もたれ部２０から遠い位置にある後席乗員Ｍの膝Ｋｎ及び膝下を保護する。
【００４２】
次に、以上詳述した本実施形態が有する効果を列記する。
（１）コントローラ３７（調節手段、検出手段）は、各センサ（検出手段）３２〜３６からの検出情報から前席１０の背もたれ部２０の背面２０ａと後席乗員Ｍの膝Ｋｎとの間隔（位置関係）を推定し、この推定結果に基づいてエアバッグ１６に供給するガス量を２段階に切り換える。エアバッグ１６は、供給されるガス量が少ないときには薄く展開膨張し、供給されるガス量が多いときには厚く展開膨張する。そして、エアバッグ１６は、前席１０の座部１１の下側に設けられ、背もたれ部２０の背面２０ａに沿ってほぼ上方に展開膨張する。その結果、前席１０の背もたれ部２０と後席乗員Ｍの膝Ｋｎとの間隔が変化しても、後席乗員Ｍの膝Ｋｎ及び膝下に対する保護機能が低下しない。
【００４３】
（２）コントローラ３７は、２つのインフレータ１５ａ，１５ｂの一方のみ又は両方を作動させ、エアバッグ１６に供給するガス量を２段階に切り換えることで、エアバッグ１６が展開膨張する厚さ（形態）を切り換える。従って、ガス量を切り換えるだけの簡単な操作によってエアバッグ１６が展開膨張する大きさを切り換えるので、容易に実施できる。
【００４４】
（３）エアバッグ１６のテザー２１ａ，２１ｂに設けられた重合部２３ａ，２３ｂのティアシーム部（破断部）２２ａ，２２ｂが、２段階で供給されるガスの圧力に応じて維持又は展開することにより、エアバッグ１６が展開膨張する厚さが切り換わる。従って、展開膨張する厚さが異なってもその内圧を所定値以上確保することができるので、大きさの変化によるエアバッグ１６の保護機能の低下を防止することができる。
【００４５】
（４）コントローラ３７は、前席１０の前後位置、その背もたれ部２０の倒れ角、後席１２の前後位置、その背もたれ部２４の倒れ角、後席乗員Ｍの着座状態から、前席１０の背もたれ部２０の背面２０ａと、後席乗員Ｍの膝Ｋｎとの間隔を推定する。従って、簡単に検出することができる各検出量から間隔を推定できるので、より高度で複雑なセンサを用いる必要がなく、容易に実施できる。
【００４６】
（５）エアバッグ１６は、前席１０の座部１１の下面に設けられるとともに、前席１０の背もたれ部２０の背面２０ａに沿って上方に展開膨張し、後席乗員Ｍの膝Ｋｎ及び膝下を保護するために、扁平状に展開膨張する。従って、背もたれ部２０と後席乗員Ｍの膝Ｋｎとの間隔が変化しても、膝Ｋｎ及び膝下に干渉することなく展開膨張し、また、膝Ｋｎ及び膝下に対する保護機能が低下し難い。
【００４７】
次に、上記一実施形態以外の実施形態を列記する。
・重合部２３ａ，２３ｂは、第１インフレータ１５ａのみからガスが供給されたときに重合状態が維持され、第１及び第２インフレータ１５ａ，１５ｂの両方からガスが供給されたときに重合状態から展開するものであればよく、ティアシーム部２２ａ，２２ｂの代わりに、接着によって重合状態が形成されてもよい。
【００４８】
・エアバッグは、供給されるガス量に応じて、展開膨張する大きさを切り換えることができればよい。例えば、図９（ａ）に示すように、その外周部に設けられた重合部４０のティアシーム部４１ａ，４１ｂ（破断部）をガス圧によって破断させ、重合部４０を展開させることで、図９（ｂ）に示すように展開する構成としてもよい。
【００４９】
・各センサ３２〜３６及びコントローラ３７が構成する検出手段は、前席の背もたれ部と後席乗員Ｍの膝下との位置関係を検出できれるものであればよい。例えば、車両のＢピラーに設けたカメラと、このカメラが撮像した背もたれ部と膝下の画像から、その間隔を求めるコンピュータからなる構成としてもよい。この場合には、複数の異なるセンサを必要とせず、部品点数及び組付工数が少なくなる。
【００５０】
・３段階に設定されたガス量に応じて２段階で破断するティアシーム部を有する重合部をテザーに設けた構成としてもよい。この場合には、前席１０の背もたれ部２０と後席乗員Ｍの膝Ｋｎとの間隔に応じて、エアバッグが展開膨張する大きさをより適切に設定することができるので、後席乗員Ｍの膝Ｋｎ及び膝下に対する保護機能がより一層低下し難い。
【００５１】
・エアバッグは、前席１０に設けられ、前席１０と後席１２との間において展開膨張するものであればよい。例えば、前席１０の座部１１に内蔵され、背もたれ部２０の背面２０ａに沿って上方に展開するものであってもよい。あるいは、背もたれ部２０の背面２０ａに設けられ、後席乗員Ｍの胸部あるいは頭部の前方に展開するものであってもよい。
【００５２】
【発明の効果】
請求項１〜７に記載の発明によれば、前席と後席乗員との位置関係が変化しても、後席乗員に対する保護機能が低下し難い。
【図面の簡単な説明】
【図１】本実施形態の後席用エアバッグ装置を示す電気ブロック図。
【図２】エアバッグモジュールが設けられた前席と後席を示す模式図。
【図３】エアバッグモジュールを示す模式側面図。
【図４】（ａ）はエアバッグモジュールを示す模式平面図、（ｂ）は同じく模式背面図。
【図５】エアバッグを示す模式背面図。
【図６】展開膨張したエアバッグを示す模式側面図。
【図７】同じく模式側面図。
【図８】テザーに設けられた重合部を示す模式斜視図。
【図９】（ａ）はエアバッグの外周部に設けられた重合部を示す模式図、（ｂ）は展開後の重合部を示す模式図。
【図１０】展開制御を示すフローチャート。
【符号の説明】
１０…前席、１１…座部、１２…後席、１５ａ…調節手段を構成する第１インフレータ、１５ｂ…同じく第２インフレータ、１６…エアバッグ、２０…背もたれ部、２０ａ…背面、２１ａ，２１ｂ…調節手段を構成するテザー、２２ａ，２２ｂ…破断部としてのティアシーム部、２３ａ，２３ｂ…重合部、３０…後席用エアバッグ装置、３１…検出手段を構成する前席位置センサ、３２…同じく前席倒れ角センサ、３３…同じく後席位置センサ、３４…同じく後席倒れ角センサ、３５…同じく後席荷重センサ、３６…検出手段及び調節手段を構成するコントローラ、４０…重合部、４１ａ，４１ｂ…破断部としてのティアシーム部、Ｋｎ…膝、Ｍ…後席乗員。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rear seat airbag device including an airbag that is deployed and inflated between a front seat and a rear seat when an impact due to a collision or the like is applied to a vehicle. In this specification, “front seat” means a seat with other seats behind, and is not limited to a driver seat and a passenger seat. The “rear seat” means a seat after the “front seat”.
[0002]
[Prior art]
As a conventional rear seat airbag device of this type, there is one in which an airbag is deployed toward a rear seat occupant from an airbag module provided in a seat base frame of a front seat. The airbag is deployed upward along the back of the backrest behind the backrest of the front seat, and then deployed in front of the chest or head of the rear seat occupant (see Patent Document 1).
[0003]
[Patent Document 1]
JP 2002-542100 A [0004]
[Problems to be solved by the invention]
However, in the airbag device described in Patent Document 1, the airbag is merely deployed and inflated to a certain size regardless of the position interval between the front seat and the rear seat occupant. For this reason, when the positional relationship between the airbag and the rear seat occupant changes due to the front / rear position of the front seat, the physique of the rear seat occupant, or the like, the protection function for the rear seat occupant may be reduced.
[0005]
The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a rear seat in which the protection function for the rear seat occupant is unlikely to deteriorate even if the positional relationship between the front seat and the rear occupant changes. The object is to provide an air bag device.
[0006]
[Means for Solving the Problems]
In the following, means for achieving the above object and its effects are described.
(1) The invention according to claim 1 is an air bag for a rear seat including an airbag that expands and inflates from the front seat toward the front seat and the rear seat, and an inflator that supplies gas to the airbag. In the bag device, the seating state of the rear seat occupant, the front seat front / rear adjustment position, the tilt angle of the front seat backrest portion, and the rear seat front / rear adjustment position and the rear seat backrest tilt angle are detected. Detection means for obtaining an estimated value of the distance between the backrest portion of the front seat and the rear seat occupant based on the detection result, and gas when the gas is supplied from the inflator provided in the airbag in a superimposed state Is maintained in either the pre-overlapped state or the state unfolded from this state in accordance with the pressure of the state, and is in the pre-overlapped state or the unfolded state To the difference A restricting means for switching a thickness of at airbag deployment Ri determines the necessity of operation of the airbag based on an estimate of the distance, the result indicating that there is a need to operate through this determination is obtained Sometimes the airbag is inflated and inflated, and the thickness at the time of inflating is adjusted based on the estimated value of the interval. As the adjustment of the thickness, the amount of gas generated from the inflator is controlled to The gist of the present invention is to provide an adjusting means for adjusting the supply amount of the control means, thereby switching the state of the restricting means between the pre-superposed state and the unfolded state .
[0007]
According to the above invention, even if the positional relationship between the front seat and the rear seat occupant changes, the airbag is deployed and inflated between the front seat and the rear seat so that the protection function for the rear seat occupant is unlikely to deteriorate. The form can be adjusted. Moreover, since the thickness which an airbag expand | deploys and can be adjusted with simple operation which only changes gas amount, it can implement easily. In addition, since the distance between the front seat and the rear seat occupant can be estimated from each detection amount that can be easily detected, it is not necessary to use a more sophisticated and complicated detection means, which can be easily performed.
[0008]
(2) The invention according to claim 2 is the rear seat airbag device according to claim 1, wherein the adjusting means is configured to determine whether or not the airbag needs to be operated based on the estimated value of the interval. When a determination is made as to whether or not the airbag needs to be operated based on whether or not the seated state of the rear seat occupant is in a correct state, and a result indicating that the airbag needs to be operated is obtained by each of these determinations. The main point is to deploy and inflate the airbag.
[0011]
(3) A third aspect of the present invention is the rear seat airbag device according to the first or second aspect, wherein the restricting means is a break that breaks in accordance with a gas supply amount set in a plurality of stages. A portion is provided, and when the gas is supplied, depending on whether the rupture portion is in a ruptured state or in an unruptured state, the pre-superposed state and the unfolded state The gist of the invention is that the thickness of the airbag is changed when the airbag is deployed and inflated.
[0012]
According to the above invention, even if the airbag is deployed and inflated in different thicknesses, the internal pressure can be secured at a predetermined value or more, so that the protection function of the airbag can be prevented from being lowered by switching the thickness. .
[0013]
(4) The invention according to claim 4 is the airbag device for a rear seat according to any one of claims 1 to 3, wherein the regulating means is provided in the airbag in a state of being overlapped in advance. The thickness of the airbag when it is deployed and inflated is changed depending on whether the tether is pre-superposed when the gas is supplied or whether it is deployed from this state. There is a summary.
[0014]
(5) The invention according to claim 5 is the rear seat airbag device according to any one of claims 1 to 3, wherein the regulating means is configured such that a part of the outer periphery of the airbag is overlapped in advance. The thickness of the airbag when it is deployed and inflated is changed depending on whether the region is pre-superposed when the gas is supplied or whether it is deployed from this state. There is a summary.
[0015]
According to the invention described in the above (4) or (5) , the thickness at which the airbag is deployed and inflated can be switched with a simple configuration.
[0016]
(6) The invention according to claim 6 is the airbag device for a rear seat according to any one of claims 1 to 5, wherein the airbag is located on a seat portion of the front seat or below the seat portion. The gist is that it is housed and expands and expands upward in a manner along the back surface of the backrest portion of the front seat.
[0017]
According to the said invention, even if the positional relationship of a front seat and a rear-seat passenger | crew changes, it expand | deploys without interfering under a knee of a rear-seat passenger | crew, and a knee and a knee can be protected.
[0018]
(7) The invention according to claim 7 is the rear seat airbag device according to any one of claims 1 to 6, wherein the airbag is flattened corresponding to the knees and below the knees of the rear seat occupant. The gist is that it expands and expands in a shape.
[0019]
According to the above invention, even if the positional relationship between the front seat and the knees and below the knees of the rear seat occupant changes, the protection function for the knees and below the knees of the rear seat occupant is unlikely to decrease.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. 1 to 8 and 10.
[0021]
As shown in FIG. 2, an airbag module 13 for protecting a rear seat occupant M seated on the rear seat 12 is fixed to the lower surface of the seat portion 11 of the front seat 10 in the vehicle.
[0022]
As shown in FIGS. 3 and 4A, the airbag module 13 is housed in a case 14 fixed to the seat portion 11, a pair of inflators 15 a and 15 b housed in the case 14, and the case 14. An airbag 16 that is deployed and inflated by gas supplied by the inflators 15a and 15b is provided.
[0023]
As shown in FIG. 4 (b), the case 14 has an opening 17 facing the rear seat 12, and the airbag 16 folded from the opening 17 is deployed to the rear seat 12 side. It has become. The opening 17 is closed by an upper lid portion 19a and a lower lid portion 19b that are separated by the tear lines 18a and 18b and opened up and down when the airbag 16 is deployed.
[0024]
As shown in FIGS. 5, 6, and 7, the airbag 16 is deployed and inflated substantially upward along the back surface 20 a of the backrest portion 20 of the front seat 10 between the front seat 10 and the rear seat 12. It has become. Further, the airbag 16 is deployed and inflated into a substantially square shape when viewed in the front-rear direction so as to have a flat shape.
[0025]
Inside the airbag 16, tethers 21a and 21b for connecting the front base fabric 16a and the rear base fabric 16b are provided. The shape of the airbag 16 that is deployed and inflated by the tethers 21a and 21b is limited, and the thickness of the airbag 16 is switched. As shown in FIG. 8, overlapping portions 23a and 23b are provided at the intermediate portions of the tethers 21a and 21b by tear seam portions 22a and 22b as fracture portions, respectively. Here, “break” means that the seams of the tear seam portions 22a and 22b are broken and the overlapping portions 23a and 23b extend.
[0026]
When the gas is supplied only from the first inflator 15a, the overlapping portions 23a and 23b do not break the tear seam portions 22a and 22b and maintain the overlapping state as shown in FIG. For this reason, the airbag 16 is thinly expanded and inflated, and the internal pressure becomes a predetermined value or more by limiting the volume after the expansion and expansion. Further, when the internal pressure is increased when the gas is supplied from the second inflator 15b in addition to the first inflator 15a and the internal pressure is increased, the overlapping portions 23a and 23b are ruptured and the tear seam portions 22a and 22b are overlapped as shown in FIG. Expand from. For this reason, the airbag 16 has an internal pressure greater than or equal to a predetermined value in a state where the airbag 16 is expanded and inflated.
[0027]
As shown in FIG. 1, in addition to the airbag module 13, the rear seat airbag device 30 includes a seat belt sensor 31, a front seat position sensor 32, a front seat tilt angle sensor 33, a rear seat position sensor 34, and a rear seat tilt. An angle sensor 35, a rear seat seating sensor 36, and a controller 37 are included. In the present embodiment, the front seat position sensor 32, the front seat tilt angle sensor 33, the rear seat position sensor 34, the rear seat tilt angle sensor 35, the rear seat seating sensor 36, and the controller 37 constitute detection means, and the first inflator 15a. The second inflator 15b, the tethers 21a and 21b, and the controller 37 constitute an adjusting means.
[0028]
The seat belt sensor 31 is attached to a buckle of a rear seat belt (not shown) and detects whether or not the rear seat occupant M is wearing a seat belt.
The front seat position sensor 32, the front seat tilt angle sensor 33, the rear seat position sensor 34, the rear seat tilt angle sensor 35, and the rear seat seat sensor 36 detect the positional relationship between the backrest 20 and the knee Kn of the rear seat occupant M. Detect various information to do. The front seat position sensor 32 detects the front / rear position of the front seat 10 from the amount of rotation of a drive motor (not shown) that moves the front seat 10 back and forth, and the front seat tilt angle sensor 33 tilts the backrest portion 20 back and forth. The tilt angle of the backrest 20 is detected from the amount of rotation of the drive motor (not shown). The rear seat position sensor 34 detects the front / rear position of the rear seat 12 from the amount of rotation of a drive motor (not shown) that moves the rear seat 12 back and forth, and the rear seat tilt angle sensor 35 is the backrest portion 24 of the rear seat 12. The tilt angle of the backrest 24 is detected from the amount of rotation of a drive motor (not shown) that tilts back and forth.
[0029]
The rear seat seating sensor 36 is provided, for example, at the front portion, the center portion, and the rear portion of the seat portion 25 of the rear seat 12. Each rear seat seating sensor 36 can estimate the seated state of the rear seat occupant M, that is, whether or not the rear seat occupant M is seated at the correct position of the seat portion 25. And the seating state in a rear part is detected. In the state in which the rear seat occupant M is seated at the correct position of the seat portion 25, the rear seat seat sensors 36 at the front, center, and rear portions all detect the seating of the rear seat occupant M. On the other hand, for example, when the child who is the rear seat occupant M stands up from the seat portion 25, none of the rear seat occupancy sensors 36 detects the seating of the rear seat occupant M. Further, when the rear seat occupant M is seated shallowly on the seat portion 25, only the front rear seat seating sensor 36 detects the seating.
[0030]
The controller 37 storing the program shown in FIG. 10 determines whether or not to operate the airbag 16 based on the operation of a program to be described later based on the impact detection result input from the impact detector (not shown). That is, when it is determined that the airbag 16 is to be operated, the controller 37 performs deployment control of the airbag 16 described below based on detection results input from the sensors 32 to 36.
[0031]
As shown in FIG. 10, the controller 37 first determines in step (hereinafter abbreviated as “S”) 100 whether or not the airbag 16 should be activated from the impact detection result input from the impact detector. . Then, when it is determined that the airbag 16 is not in a state to be activated, this process is terminated.
[0032]
On the other hand, when it is determined in S100 that the airbag 16 should be operated, in S110, based on the detection result input from the seatbelt sensor 31, it is determined whether or not the rear seat occupant M is wearing the seatbelt. to decide. If it is determined that the seat belt is not worn, the present process is terminated.
[0033]
If it is determined in S110 that the rear seat occupant M is wearing a seat belt, then in S120, the seating state of the rear seat occupant M on the seat 25 is correct from the detection result of each rear seat seat sensor 36. Determine whether or not. Then, when the seated state of the rear seat occupant M is not correct, the present process is terminated without operating the airbag 16.
[0034]
On the other hand, when the seated state of the rear seat occupant M is correct in S120, S130 is executed next.
In S130, the estimated distance G between the back surface 20a of the backrest 20 of the front seat 10 and the knee Kn of the rear seat occupant M is obtained from the detection results input from the sensors 32 to 36. The estimated distance G is obtained from the front / rear and vertical positions of the back surface 20a of the backrest 20 and the same position of the knee Kn of the rear seat occupant M. Note that the position of the back surface 20 a of the backrest portion 20 is obtained from the front-rear position of the front seat 10 and the tilt angle of the backrest portion 20. The position of the knee Kn of the rear seat occupant M is obtained from the front and rear positions of the rear seat 12, the tilt angle of the backrest 24, and the seated state of the rear seat occupant M.
[0035]
When S130 is executed, next, in S140, it is determined whether or not the estimated distance G is equal to or larger than the first predetermined distance determination value G0, whereby the back 20a of the backrest 20 and the rear seat occupant M are determined. It is determined whether the knee Kn is too close to the extent that it cannot be effectively protected by the airbag 16. When the estimated interval G is less than the first interval determination value G0, it is determined that the backrest 20 and the knee Kn are too close to each other, and the present process is terminated without operating the airbag 16.
[0036]
On the other hand, when the estimated interval value G is equal to or greater than the first interval determination value G0 in S140, it is determined that the backrest 20 and the knee Kn are not too close, and then S150 is executed.
[0037]
In S150, the size of the airbag 16 to be deployed and inflated is determined by determining whether or not the estimated interval value G is equal to or greater than a preset second interval determination value G1. If the estimated interval G is less than the second interval determination value G1 in S150, it is determined that it is appropriate to expand and inflate the airbag 16 thinly, and then only the first inflator 15a is activated in S160. Then, this process is terminated.
[0038]
On the other hand, when the estimated interval value G is equal to or greater than the second interval determination value G1 in S150, it is determined that it is appropriate to expand and inflate the airbag 16 more appropriately. Next, in S170, the first inflator 15a and After the second inflator 15b is actuated together, this process ends.
[0039]
Next, the operation of the present embodiment configured as described above will be described.
When the rear seat occupant M is not wearing a seat belt or when the seating state is not correct, the controller 37 does not activate the airbag 16 even if an impact to activate the airbag 16 is applied to the vehicle. Therefore, even if an impact is applied to the vehicle, the operation is stopped when it is not appropriate to operate the airbag 16.
[0040]
Further, when the front and rear positions of the front seat 10 are adjusted closer to the rear seat 12 or when the backrest portion 20 is largely tilted rearward, the back surface 20a of the backrest portion 20 and the knee Kn of the rear seat occupant M The interval is relatively small. When an impact is applied to the vehicle in this state, the controller 37 operates only the first inflator 15a. For this reason, the airbag 16 is expanded and inflated upward along the back surface 20a of the backrest 20 in a relatively narrow space between the backrest 20 and the knees of the rear seat occupant M, and thinly inflated flat. Accordingly, even when the distance between the backrest 20 and the knee Kn of the rear seat occupant M is narrow, the airbag 16 is deployed and inflated without interfering under the knee of the rear seat occupant M, and is in a position close to the backrest 20. The knee Kn and the lower knee of the rear seat occupant M are protected.
[0041]
On the other hand, when the front / rear position of the front seat 10 is adjusted away from the rear seat 12 or the backrest 20 is raised, the distance between the back surface 20a of the backrest 20 and the knee Kn of the rear seat occupant M is relative. Become bigger. When an impact is applied to the vehicle in this state, the controller 37 operates both the first inflator 15a and the second inflator 15b. Therefore, the airbag 16 is expanded and inflated upward along the back surface 20a of the backrest portion 20 in a relatively wide space between the backrest portion 20 and the knees of the rear seat occupant M, and is inflated thickly. Therefore, the airbag 16 is deployed and inflated without interfering with the knees of the backseat occupant M even when the distance between the backrest 20 and the knee Kn is wide, and the airbag 16 is far from the backrest 20. Protect knee Kn and below knee.
[0042]
Next, effects of the present embodiment described in detail above will be listed.
(1) The controller 37 (adjustment means, detection means) determines the distance between the back surface 20a of the backrest portion 20 of the front seat 10 and the knee Kn of the rear seat occupant M from the detection information from the sensors (detection means) 32 to 36 ( (Positional relationship) is estimated, and the amount of gas supplied to the airbag 16 is switched to two stages based on the estimation result. The airbag 16 expands and inflates thinly when the amount of gas supplied is small, and expands and inflates thickly when the amount of gas supplied is large. The airbag 16 is provided below the seat portion 11 of the front seat 10 and is deployed and inflated substantially upward along the back surface 20a of the backrest portion 20. As a result, even if the distance between the backrest portion 20 of the front seat 10 and the knee Kn of the rear seat occupant M changes, the protection function for the knee Kn and the lower knee of the rear seat occupant M does not deteriorate.
[0043]
(2) The controller 37 operates only one or both of the two inflators 15a and 15b, and switches the amount of gas supplied to the airbag 16 to two stages, whereby the airbag 16 is deployed and inflated (form) Switch. Therefore, since the magnitude | size which the airbag 16 expand | deploys is switched by simple operation which only switches the gas quantity, it can implement easily.
[0044]
(3) By maintaining or deploying the tear seam portions (breaking portions) 22a and 22b of the overlapping portions 23a and 23b provided in the tethers 21a and 21b of the airbag 16 according to the pressure of the gas supplied in two stages The thickness at which the airbag 16 is deployed and inflated is switched. Accordingly, the inner pressure can be ensured at a predetermined value or more even if the thickness of expansion and expansion is different, so that the deterioration of the protection function of the airbag 16 due to the change in size can be prevented.
[0045]
(4) The controller 37 determines the position of the front seat 10 from the front and rear positions of the front seat 10, the tilt angle of the backrest portion 20, the front and rear positions of the rear seat 12, the tilt angle of the backrest portion 24, and the seated state of the rear seat occupant M. The distance between the back surface 20a of the backrest 20 and the knee Kn of the rear seat occupant M is estimated. Therefore, since the interval can be estimated from each detection amount that can be easily detected, it is not necessary to use a more sophisticated and complicated sensor, and the operation can be easily performed.
[0046]
(5) The airbag 16 is provided on the lower surface of the seat portion 11 of the front seat 10 and is expanded and inflated upward along the back surface 20a of the backrest portion 20 of the front seat 10, so that the knee Kn and the lower knee of the rear seat occupant M In order to protect, it expands and expands in a flat shape. Therefore, even if the distance between the backrest 20 and the knee Kn of the rear seat occupant M is changed, it expands and expands without interfering with the knee Kn and below the knee, and the protective function against the knee Kn and below the knee is unlikely to decrease.
[0047]
Next, embodiments other than the one embodiment will be listed.
-The superposition | polymerization part 23a, 23b maintains a superposition | polymerization state, when gas is supplied only from the 1st inflator 15a, and expand | deploys from a superposition state when gas is supplied from both the 1st and 2nd inflators 15a, 15b. The polymerization state may be formed by adhesion instead of the tear seam portions 22a and 22b.
[0048]
-The air bag should just be able to switch the magnitude | size which expand | deploys according to the gas amount supplied. For example, as shown in FIG. 9 (a), tear seam portions 41a and 41b (breaking portions) of the overlapping portion 40 provided on the outer peripheral portion thereof are broken by the gas pressure, and the overlapping portion 40 is developed, whereby FIG. It is good also as a structure expand | deployed as shown to (b).
[0049]
-The detection means which each sensor 32-36 and the controller 37 comprise should just be able to detect the positional relationship of the backrest part of a front seat, and the lower-seat passenger | crew's M below knee. For example, it is good also as a structure which consists of a camera provided in B pillar of a vehicle, and the computer which calculates | requires the space | interval from the backrest part and the image under a knee which this camera imaged. In this case, a plurality of different sensors are not required, and the number of parts and assembly man-hours are reduced.
[0050]
-It is good also as a structure which provided the superposition | polymerization part which has a tear seam part which fractures | ruptures in two steps according to the gas amount set to three steps in the tether. In this case, the size of the airbag to be deployed and inflated can be set more appropriately in accordance with the distance between the backrest portion 20 of the front seat 10 and the knee Kn of the rear seat occupant M. Therefore, the rear seat occupant M The protective function for the knee Kn and the lower knee is more difficult to decrease.
[0051]
-An airbag should just be provided in the front seat 10 and expand | deployed between the front seat 10 and the rear seat 12. For example, it may be built in the seat portion 11 of the front seat 10 and developed upward along the back surface 20 a of the backrest portion 20. Alternatively, it may be provided on the back surface 20a of the backrest 20 and deployed in front of the chest or head of the rear seat occupant M.
[0052]
【The invention's effect】
According to the first to seventh aspects of the present invention, even if the positional relationship between the front seat and the rear seat occupant changes, the protection function for the rear seat occupant is unlikely to deteriorate.
[Brief description of the drawings]
FIG. 1 is an electric block diagram showing a rear seat airbag device of the present embodiment.
FIG. 2 is a schematic diagram showing a front seat and a rear seat provided with an airbag module.
FIG. 3 is a schematic side view showing an airbag module.
4A is a schematic plan view showing an airbag module, and FIG. 4B is a schematic rear view of the same.
FIG. 5 is a schematic rear view showing an airbag.
FIG. 6 is a schematic side view showing the airbag inflated and inflated.
FIG. 7 is a schematic side view of the same.
FIG. 8 is a schematic perspective view showing an overlapping portion provided in the tether.
9A is a schematic diagram showing a superposed portion provided on the outer peripheral portion of an airbag, and FIG. 9B is a schematic diagram showing a superposed portion after deployment.
FIG. 10 is a flowchart showing deployment control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Front seat, 11 ... Seat part, 12 ... Rear seat, 15a ... The 1st inflator which comprises an adjustment means, 15b ... The same 2nd inflator, 16 ... Air bag, 20 ... Backrest part, 20a ... Back, 21a, 21b ... tethers constituting adjusting means, 22a, 22b ... tear seam parts as breaking parts, 23a, 23b ... overlapping parts, 30 ... rear seat airbag device, 31 ... front seat position sensor constituting detecting means, 32 ... Front seat tilt angle sensor 33 ... similar rear seat position sensor 34 ... same rear seat tilt angle sensor 35 ... same rear seat load sensor 36 ... controller constituting detection means and adjustment means 40 ... overlapping unit 41a, 41b ... Tear seam portion as a breaking portion, Kn ... Knee, M ... Rear seat occupant.

Claims

In a rear seat airbag device comprising an airbag that expands and inflates from the front seat toward the front seat and the rear seat, and an inflator that supplies gas to the airbag.
Based on the detection result, the seating state of the rear seat occupant, the front seat front / rear adjustment position, the tilt angle of the front seat backrest, and the rear seat front / back adjustment position and the rear seat backrest tilt angle are detected. Detecting means for obtaining an estimated value of the distance between the backrest of the front seat and the rear seat occupant;
It is provided in the airbag in a pre-superposed state, and is maintained in either the pre-overlapped state or the deployed state depending on the gas pressure when the gas is supplied from the inflator. Restricting means for switching the thickness of the airbag when it is deployed and inflated depending on whether it is in the pre-superposed state or the deployed state,
Based on the estimated value of the interval, it is determined whether or not the airbag needs to be operated. When a result indicating that the airbag needs to be activated is obtained through this determination, the airbag is deployed and inflated, and based on the estimated value of the interval. The thickness at the time of deployment and inflation is adjusted, and as the adjustment of the thickness, the amount of gas generated from the inflator is controlled to adjust the amount of gas supplied to the airbag, thereby changing the state of the regulating means. An air bag device for a rear seat , comprising adjusting means for switching between a state of being overlaid in advance and the state of being deployed .

The rear seat airbag device according to claim 1,
In addition to determining whether or not the airbag needs to be operated based on the estimated value of the interval, the adjusting means determines whether or not the airbag needs to be operated based on whether or not the seated state of the rear seat occupant is in a correct state. And the airbag is deployed and inflated when a result indicating that the airbag needs to be activated is obtained by each of these determinations.

The rear seat airbag device according to claim 1 or 2,
The restricting means is provided with a rupture portion that breaks according to a gas supply amount set in a plurality of stages, and the rupture portion is in a state of being broken or broken when a gas is supplied. Depending on whether there is no state, it is maintained in either the pre-overlapped state or the deployed state, thereby switching the thickness of the airbag when it is deployed and inflated
A rear seat airbag device characterized by the above.

In the airbag apparatus for backseats as described in any one of Claims 1-3,
The restricting means is a tether provided inside the airbag in a state of being overlaid in advance, and when the gas is supplied, the tether is in a state of being overlaid in advance or in a state of being deployed from this state. The thickness when the airbag is deployed and inflated is switched depending on the difference
A rear seat airbag device characterized by the above.

In the airbag apparatus for backseats as described in any one of Claims 1-3,
The restricting means is a part in which a part of the outer periphery of the airbag is preliminarily overlapped, and when the gas is supplied, the part is in a state of being preliminarily superimposed or in a state of being developed from this state. The thickness when the airbag is deployed and inflated is switched depending on the difference
A rear seat airbag device characterized by the above.

In the airbag apparatus for backseats as described in any one of Claims 1-5,
The airbag is accommodated in the seat portion of the front seat or below the seat portion, and is deployed and inflated upward in a manner along the back surface of the backrest portion of the front seat.
A rear seat airbag device characterized by the above.

In the airbag apparatus for backseats as described in any one of Claims 1-6,
The airbag is deployed and inflated in a flat shape corresponding to the knee and lower knee of the rear seat occupant.
A rear seat airbag device characterized by the above.