JP3897252B2

JP3897252B2 - Starter

Info

Publication number: JP3897252B2
Application number: JP2002363023A
Authority: JP
Inventors: 寛金田; 村田　　光広; 伸二宇佐見; 一夫平間; 達彌齋藤
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2002-12-13
Filing date: 2002-12-13
Publication date: 2007-03-22
Anticipated expiration: 2022-12-13
Also published as: JP2004190648A

Description

【０００１】
【発明の属する技術分野】
本発明は、エンジンを始動する際に使用する始動装置に関するものである。さらに詳しくは、遊星歯車を用いた減速機を備える始動装置に関するものである。
【０００２】
【従来の技術】
内燃機関（以下単に「エンジン」という。）は、その始動に際して始動装置（以下、適宜「スタータ」という。）による回転駆動を必要とする。この始動装置には、ギヤ式スタータ等があるが、いずれも電気モータ（以下単に「モータ」という。）が駆動源である点で共通する。エンジンの始動には、その種類や排気量にも依るが、比較的大きなトルクが必要となる。このため、モータでエンジンを直接クランキングさせようとすると、モータの体格が自ずと大きくなってしまう。そこで、軽量コンパクト化が求められる最近の始動装置では、減速機をモータとエンジンとの間に介在させて、減速比を大きくすることにより始動に必要な高トルクを得ている。
【０００３】
この減速機にも種々あるが、コンパクトで大きな減速比の得られる遊星歯車式減速機が多用されている。この減速機では、モータからサンギヤへ入力された駆動力がプラネタリギヤを支承するキャリアから高トルクで出力される。この前提として、その出力に応じて生じる大きな反力（トルク）がインターナルギヤで受承されなければならない。つまり、インターナルギヤは周方向への回動が拘束されている必要がある。
【０００４】
ところで、エンジンは吸気、圧縮等の工程によって、回転に必要なトルクが急激に変動し、その回転数も脈動する。スタータのモータはこのような荷重変動等に巧く追従できないため、インターナルギヤに作用する上記反力も一定しない。その結果、インターナルギヤを単に拘束しただけでは、インターナルギヤの振動等によってエンジン始動時に不快音が発生し得る。
そこで、インターナルギヤ等へ作用する荷重変動等を緩和、吸収するために、インターナルギヤとその拘束部分との間にゴム等の弾性体からなる緩衝部材を配設することが行われている。このような開示は、例えば、下記の特許文献１にある。
【０００５】
【特許文献１】
特開平５−５２１６６号公報
【０００６】
【発明が解決しようとする課題】
上記特許文献１では、インターナルギヤの側面から軸方向に延在する突起を緩衝部材（弾性体）で保持するようにしているから、外径方向へスタータが大型化することはない。しかし、この場合、インターナルギヤに係合した回動板に別途摩擦板を押圧させて、その間で発生する摩擦力によってインターナルギヤを拘束させている。このため、始動装置の構造が複雑となっている。また、特許文献４で使用されている緩衝部材は略直方体状のゴムであり、その収納部の内壁との接触面積が大きい。このため、緩衝部材の圧縮作動性が良くなく摩耗等も生じ易く、信頼性の向上を図り難い。また、その緩衝部材はインターナルギヤの周方向の反力を受承するに過ぎず、その軸方向の支持については具体的に開示されていない。
【０００７】
本発明は、このような事情に鑑みて為されたものであり、始動時の不快音等の解消と共に緩衝部材の耐久性や全体的な信頼性の向上を図れる始動装置を提供することを目的とする。
【０００８】
【課題を解決するための手段および発明の効果】
そこで、本発明者はこの課題を解決すべく鋭意研究し、試行錯誤を重ねた結果、緩衝部材をインターナルギヤの外周側ではなくその軸方向側方に配設すると共にその緩衝部材の軸方向側に弾性突部を設けることを思いつき、本発明を完成するに至った。
すなわち、本発明の始動装置は、駆動モータと、該駆動モータから入力を受けて回転するサンギヤと該サンギヤの外周側に該サンギヤと同心的に配設されるインターナルギヤと該サンギヤおよび該インターナルギヤに噛合するプラネタリギヤと該プラネタリギヤを回転自在に支承すると共に該サンギヤの入力を減速して出力するキャリアと周方向へ可動な状態で配設された該インターナルギヤの回転を拘束する回転拘束手段を有する減速機とを備え、該駆動モータが該減速機を介してエンジンを始動回転させる始動装置において、
前記回転拘束手段は、前記インターナルギヤに設けられ、該インターナルギヤと一体的に回動する可動係止部と、該可動係止部に対向し、かつ、該可動係止部と周方向に対峙して周方向に不動な状態で配設された不動係止部と、少なくとも該可動係止部と不動係止部との間に弾性保持されて前記駆動モータが前記減速機を介してエンジンを始動回転させる際に前記インターナルギヤに作用する反動を弾性的に受承する弾性塊部と該弾性塊部の軸方向側の少なくとも一方から突出して前記インターナルギヤを軸方向に弾性保持する弾性突部とを有する緩衝部材と、からなることを特徴とする（請求項１）。
【０００９】
本発明の始動装置の場合、減速機のインターナルギヤは、可動係止部、不動係止部および緩衝部材とからなる回転拘束手段によって、少なくとも一方への回転が規制される。
次に、始動装置によるエンジンの始動開始時、インターナルギヤはキャリアからの出力と反対方向に反力（反対方向のトルク）を受ける。この反力はインターナルギヤと一体的に回動する可動係止部から緩衝部材の弾性塊部を介して不動係止部によって受承されて、インターナルギヤは反力方向の回転が拘束される。ここで、インターナルギヤに作用する反力は、弾性塊部の存在によって、弾性的に穏やかに不動係止部によって受承される。従って、各部に衝撃的な荷重が加わることもなく、係止部材同士の直接接触による不快音等が生じることもない。また、この緩衝部材はいわゆる防振材の役割をも果すため、減速機やその周囲で生じる振動や音をも吸収し得る。こうして、本発明の減速機は、比較的簡易な構造でありながら、始動装置の作動時に発生する振動や不快音等を十分に低減できる。
【００１０】
ところで、本発明の緩衝部材は、上記弾性塊部に加えて、その軸方向側の少なくとも一方から突出した弾性突部を有する。この弾性突部は、前記インターナルギヤを軸方向に弾性保持する。つまり、先ず、弾性突部はインターナルギヤのスラスト軸受のような機能を果す。そして、インターナルギヤの振動やブレ等が抑制されるので、インターナルギヤの摩耗等を招くことなく、安定した減速出力が得られる。
またこの弾性突部は、弾性塊部の軸方向側の端面等よりも突出しているため、緩衝部材の軸方向側にある摺動壁面との接触面積が非常に小さくなる。このため、弾性塊部の軸方向側の側面が全面的に、弾性塊部を収納するケースの壁面等と摺接する場合に比べて、弾性塊部の圧縮作動時の動きが非常にスムーズとなる。加えて、その弾性突部が摺動壁面等と主に摺接することから、弾性塊部自体の摩耗や劣化等を生じることがほとんどなく、緩衝部材の信頼性を向上させることができる。
【００１１】
さらに前記弾性突部を前記弾性塊部の前記不動係止部側に設けると好適である（請求項２）。
これにより、弾性突部自体も実質的にほとんど摺動しなくなり、弾性塊部のみならず弾性突部の摩耗も抑制されて、緩衝部材の信頼性ひいては始動装置の信頼性が一層向上する。また、弾性突部を設けることで、その付近の弾性塊部の剛性が向上して、始動装置の作動時等に圧縮された弾性塊部の不用意な変形も抑制できるので、より緩衝部材の信頼性が向上し得る。
【００１２】
前記回転拘束手段は、さらに、前記可動係止部から所定間隔おいて配設され該可動係止部と一体的に回動する可動当接部と、該可動当接部に対向して軸方向へ延びると共に該可動当接部と周方向に対峙して周方向に不動な状態で配設された不動当接部とを有し、該可動係止部および該不動係止部による前記弾性塊部の圧縮量を該可動当接部と該不動当接部との当接によって制限可能とすると好適である（請求項３）。
【００１３】
この場合、インターナルギヤに大きな反力が作用したときでも、その回転は可動当接部と不動当接部とが当接するまでの範囲に制限されている。従って、上記可動係止部および不動係止部による弾性塊部の圧縮量も所定範囲内に制限される。これにより、圧縮量の過多による緩衝部材の破損、損傷、早期疲労等を未然に防止できる。そして、緩衝部材の信頼性ひいては始動装置の信頼性が向上する。さらに、インターナルギヤに大きな反力が作用する場合でも、可動当接部と不動当接部とがいわゆる回り止として作用して、その回転が規制されるため、駆動モータからの入力が効率良く減速されてキャリアから出力される。
【００１４】
なお、本発明の始動装置では、可動係止部と不動係止部とが弾性塊部により弾性保持されているので、可動係止部へ加わる荷重は始動装置の作動当初から弾性的であり緩やかである。また、エンジン始動後等に弾性塊部が復帰する場合も、可動係止部へ加わる力は緩やかである。ここで、弾性塊部が可動係止部と不動係止部との間に弾性保持されている状態は、例えば、略弾性塊状の緩衝部材を少し圧縮させつつ、可動係止部と不動係止部との間へ組込むことで得られる。
こうして、不快音等の抑制された、信頼性や効率の高い始動装置が得られる。また、可動当接部と不動当接部との間隔を調整することで上記弾性塊部に許容される圧縮量（最大圧縮量）を容易に設定変更できるので、その減速機の設計自由度も大きい。
【００１５】
ところで、緩衝部材としてはバネ、合成樹脂、合成ゴム等種々考え得るが、本発明のように緩衝部材が合成ゴムからなると、形状自由度が大きく、性能、信頼性、コスト、組付け等の点で好ましい。特に、弾性塊部が合成ゴムからなる場合、弾性塊部の最大圧縮率が１０〜３０％に収るように前記可動当接部および前記不動当接部を配置すると好適である（請求項４）。
【００１６】
合成ゴムの一般的な許容最大圧縮率は、耐久性を考えて通常２０％前後と言われているが、本発明の弾性塊部のように始動時の僅かな時間しか使用されないものは、その圧縮率が２０％を超えても、その信頼性が長期間損われることはない。但し、圧縮率が３０％を超えると、弾性塊部等の破損や損傷等を招き得るため好ましくない。そこで本発明の場合、その圧縮率を３０％内に納めた。なお、可動当接部および不動当接部を設けているのでその圧縮率の上限を制限することは容易である。圧縮率の下限を１０％としたのは、弾性塊部の弾性を有効利用するためである。
【００１７】
これまで、可動係止部によって弾性塊部が圧縮される場合について主に説明してきた。しかし、可動係止部に作用する力の方向は、エンジン始動前後で変化する。このため、可動係止部ひいてはインターナルギヤは、その反力方向と逆方向へも回転し得る。このときも僅かかもしれないが、減速機で振動や不快音を発生し得る。このような振動や不快音等も低減されるのが好ましい。
【００１８】
そこで、前記緩衝部材は、前記弾性塊部を形成する主弾性塊部と、前記可動係止部と前記不動当接部との間に弾性保持される副弾性塊部と、該可動係止部を跨いで該主弾性塊部と該副弾性塊部とを架橋する架橋部とを有し、該主弾性塊部の該副弾性塊部に対する周方向長比は４〜６であると好適である（請求項５）。
これにより、可動係止部は副弾性塊部によって主弾性塊部の裏側でも弾性保持される。その結果、可動係止部ひいてはインターナルギヤはいずれの回転方向にも弾性保持された状態となる。よって、可動係止部は一層安定して保持された状態となり、減速機で生じる不快音等は著しく低減され得る。また、主弾性塊部と副弾性塊部とは架橋部で連結されているので、組付けや部品管理が非常に容易となる。
【００１９】
ここで、主弾性塊部の副弾性塊部に対する周方向長比を４〜６としたのは、主弾性塊部の圧縮方向により大きな力（つまり、始動時の反力）が作用する一方、副弾性塊部の圧縮方向（反力の反対方向）に作用する力はあまり大きくはないからである。周方向長比が４未満では主弾性塊部の耐久性の確保が難しくなり、逆に周方向長比が６を超えるとコンパクト化を図りづらくなるからである。なお、周方向長比は、主弾性塊部と副弾性塊部の中心円弧長で比較すれば良い。
上記弾性塊部（または主弾性塊部）は、周方向の略中央部が端部よりも細く括れ周方向に収縮自在であると好適である（請求項６）。
【００２０】
本発明の場合、緩衝部材がインターナルギヤに作用する反力を穏やかに吸収するには、その弾性塊部が変形し易いことが必要である。そこで、上記のように弾性塊部の中央部が括れていると、少なくともその中央部で変形抵抗が小さくなる。また、弾性塊部を圧縮したとき、その括れた部分が周囲へ膨張し、その部分で圧縮に伴う形状変化を起すため、弾性塊部の弾性が有効に利用される。こうして、略中央に括れ部分を設けることで、衝撃吸収能の大きな緩衝部材が得られる。なお、上記弾性塊部は、逆に端部では括れていないため、その両端部では可動係止部および不動係止部に安定して保持される。
【００２１】
本発明の場合、配設する緩衝部材の形態や数量等は特に限定されないが、始動装置のコンパクト化やインターナルギヤの安定した作動を確保するために、周方向の３カ所以上に緩衝部材をそれぞれ均等に配設すると好ましい。そこで、前記可動係止部および前記可動当接部と前記不動係止部および前記不動当接部は、それぞれ、３対以上周方向に均等に配設されていると好適である（請求項７）。同様に、前記可動当接部および前記不動当接部は、それぞれ、３対以上周方向に均等に配設されていると好適である（請求項８）。
【００２２】
これにより、始動開始時のインターナルギヤの傾きや偏りを抑制でき、始動装置の滑らかな作用が確保される。また、始動開始時の反力等も複数の弾性塊部で受けられるため、緩衝部材を小型化し安定した衝撃吸収能が得られる。
なお、複数箇所に緩衝部材を設ける場合、それが環状に一体化されていると部品管理や組付等の点で好ましい。もっとも、例えば、上記主弾性塊部、副弾性塊部および架橋部等を１個として、これを複数用いて組付ける方が一層好ましい。主弾性塊部の圧縮等に伴う緩衝部材相互間の引きずり等を防止して緩衝部材の信頼性の向上を図れるからである。
【００２３】
ところで、上記可動係止部と可動当接部とはインターナルギヤと一体的に回転するとしても、両者が一体である必要は必ずしもない。例えば、インターナルギヤと可動係止部および可動当接部とが別部材で構成されて、両者が一体的に回転するようような係止関係にあっても良い。
もっとも、それらを一体とすることで、部品管理や組付けが容易となり好ましい。また、複雑な形状のものでも樹脂一体成形によれば比較的容易に低コストで得ることができる。
【００２４】
そこで、前記インターナルギヤと前記可動係止部と前記可動当接部とは、樹脂一体成形された略有底円筒状の樹脂部材とし、インターナルギヤは、樹脂部材の円筒内周面に形成された内歯とし、可動係止部および可動当接部は、それぞれ、樹脂部材の外側底面から軸方向に突出した可動係止突起および可動当接突起とすると好適である（請求項９）。
なお、本発明の場合、インターナルギヤや可動係止部に作用する反力等は緩衝部材によって十分に衝撃吸収されるから、それらが樹脂一体成形されたものであっても、破損、損傷等は生じず、耐摩耗性等にも優れ、信頼性も高い。
【００２５】
もっとも、回転が拘束された不動係止部や不動当接部は、上記樹脂部材等とは独立して、下記ケース等として別途設ける必要がある。
すなわち、前記不動係止部および不動当接部は、それぞれ、前記樹脂部材の底面外側に対向して回転が規制された略有底円筒状のケースの底面から軸方向に突出した不動係止突起および不動当接突起であり、前記緩衝部材は、該ケースの円筒内部に設けられた凹部に収納されると好適である（請求項１０）。
【００２６】
なお、上記不動係止部や不動当接部についていう「不動」とは、実質的に回動しないという意味であって、多少のがたつき等を問題とするものではない。また、本発明の始動装置は、ギア式スタータに限らず、他のタイプのスタータでも良い。さらに、本明細書でいう「周方向」または「軸方向」とは、減速機の回転中心軸に対するものである。
【００２７】
【発明の実施の形態】
次に、実施形態を挙げ、本発明をより詳しく説明する。
（第１実施形態）
本発明の始動装置の一実施形態であるギヤ式スタータ（以下単に「スタータ」という。）Ｓを図１に示す。このスタータＳは、主に、減速機１０と、モータ８０とマグネットスイッチ９０とからなる。モータ８０の出力は減速機１０を介して、後述のキャリア１３から外周面にヘリカルスプラインの形成された出力軸へ伝達される。そのヘリカルスプライン上には、オーバランニングクラッチ（ワンウェイクラッチ）８２とピニオンギヤ８３とが配設されている。そのオーバランニングクラッチ８２およびピニオンギヤ８３は、始動時、マグネットスイッチ９０によるレバー操作によって軸方向へ（図１の左側へ）押し出される。そして、ピニオンギヤ８３は、エンジンのクランクシャフトに取付けられたリングギヤに一時的に噛合し、エンジンをクランキングする。エンジンが始動すると、オーバランニングクラッチ８２によってスタータＳのピニオンギヤ８３は空転し、モータ８０の過回転が防止されるようになっている。
【００２８】
ところで、減速機１０は、モータ８０から延在するモータ主軸８１に形成したサンギヤ１１と、その周囲に配設されサンギヤ１１に噛合する３つのプラネタリギヤ１２と、このプラネタリギヤ１２を自転および公転可能に支持するキャリア１３と、プラネタリギヤ１２の外周側に配設されてプラネタリギヤ１２に噛合するインターナルギヤ１４９を円筒内面に備えた円筒樹脂部材１４と、この円筒樹脂部材１４の軸方向前方側（図１の左側）に設けられた収納ケース１８（ケース）と、円筒樹脂部材１４と収納ケース１８との間に介在する緩衝部材１５とからなる。円筒樹脂部材１４の軸方向後端面には覆板１９が設けられており、モータ８０のモータハウジングの前方部を閉口すると共に円筒樹脂部材１４の軸後方への移動が規制されている。
【００２９】
次に、本実施形態の特徴部分である円筒樹脂部材１４と緩衝部材１５と収納ケース１８とからなる回転拘束手段について説明する。
円筒樹脂部材１４は、図２に示すように略有底円筒状をしており、熱可塑性樹脂によって一体成形されたものである。上記インターナルギヤ１４９も、後方（図右側）に位置する円筒内面に一体成形されている。円筒樹脂部材１４の前方にある環状の底面には、軸方向前方に突出した３対の可動係止突起１４１および可動当接突起１４２が、放射状かつ均等に設けられている。可動当接突起１４２の肉厚は可動係止突起１４１の肉厚よりも厚く、大きな反力を安定して受承できるようにしてある。
【００３０】
また、円筒樹脂部材１４は、底面の内周側および外周側から前方に少し突出した内環状突起１４５および外環状突起１４６を備える。そして、それらと上記可動係止突起１４１および可動当接突起１４２とによって、少し窪んだ主可動凹部１４３および副可動凹部１４４が交互に形成されている。なお、これらの主可動凹部１４３および副可動凹部１４４の周方向長比は、上記可動係止突起１４１を隣接する可動当接突起１４２間のいずれに配置するかにより容易に調整できる。
【００３１】
緩衝部材１５は、図３に示すように主弾性塊部１５１と副弾性塊部１５２とその両者を架橋して連結する架橋部１５３とかなり、耐油性の合成ゴム（ＮＢＲ等）により一体成形されたものである。ここで、耐油性の合成ゴムを使用したのは、摺動抵抗低減等のために使用するグリスが付着しても劣化等せず、緩衝部材１５の機能が長期間維持されるようにするためである。
【００３２】
主弾性塊部１５１は扇型ブロック状であり略中央部の周囲が括れた状態となっている。また、上記収納ケース１８に接する主弾性塊部１５１の外周端側には半球状の弾性突起１５４（弾性突部）が両面側に設けられている。副弾性塊部１５２も扇型ブロック状であるが、主弾性塊部１５１よりは周方向長がかなり短い。本実施形態では、主弾性塊部１５１と副弾性塊部１５２との周方向長比を約５：１とした。架橋部１５３は、主弾性塊部１５１と副弾性塊部１５２との内側端部を帯状に連結するものである。
【００３３】
収納ケース１８は、図４に示すように略円盤状をしており、アルミニウム合金製鋳物に適宜切削加工を施したものである。収納ケース１８の前方（図左側）はほぼ平面板状に形成されているが、その裏側（図右側）には軸方向後方に突出した３対の不動係止突起１８１および不動当接突起１８２が放射状かつ均等に設けられている。不動当接突起１８２の肉厚は不動係止突起１８１の肉厚よりも厚く、大きな反力を安定して受承できるようにしてある。
【００３４】
また、収納ケース１８は、裏面側の内周側および外周側からは後方に突出した内環状突起１８５および外環状突起１８６を備える。そして、それらと上記不動係止突起１８１および不動当接突起１８２とによって、窪んだ主不動凹部１８３および副不動凹部１８４が交互に形成されている。なお、これらの主不動凹部１８３および副不動凹部１８４の周方向長比は、上記不動係止突起１８１を隣接する不動当接突起１８２間のいずれに配置するかにより容易に調整できる。
収納ケース１８は外周部に係止片１８９を有する。この係止片１８９はスタータＳのハウジングに係合して（図示せず）、収納ケース１８が周方向に回転しないように拘束してある。
【００３５】
次に、上記円筒樹脂部材１４、緩衝部材１５および収納ケース１８の組付けについて図５および図６を用いて説明する。図５に三者の分解配置図を示したものであり、図６は緩衝部材１５を円筒樹脂部材１４に組付けた状態を示すものである。なお、図６は、便宜上、緩衝部材１５が円筒樹脂部材１４に組み付けた状態を示すが、実際には、緩衝部材１５が収納ケース１８に組付けられた後に、円筒樹脂部材１４が組付けられる。これを踏まえて以下説明する。
【００３６】
先ず、緩衝部材１５を収納ケース１８に組付ける。この際、収納ケース１８の不動係止突起１８１と不動当接突起１８２との間に緩衝部材１５を嵌め込むようにして組付ける。そして、円筒樹脂部材１４に形成された可動係止突起１４１を、緩衝部材１５の主弾性塊部１５１および副弾性塊部１５２の間に押込むようにして組付ける。これにより、主弾性塊部１５１および副弾性塊部１５２は、可動係止突起１４１を弾性的に挟持した状態となる。このような緩衝部材１５と円筒樹脂部材１４との組付けを周方向の３カ所で行う。これにより、不動係止突起１８１は円筒樹脂部材１４の可動当接突起１４２と緩衝部材１５の主弾性塊部１５１との間にほぼ挟持された状態となる。一方、不動当接突起１８２は、円筒樹脂部材１４の可動係止突起１４１との間で緩衝部材１５の副弾性塊部１５２を弾性的に挟持した状態となる。
【００３７】
なお、円筒樹脂部材１４の内環状突起１４５および外環状突起１４６と、収納ケース１８の内環状突起１８５および外環状突起１８６とは、それぞれ、対応するように形成されており、円筒樹脂部材１４と収納ケース１８とによってほぼ機密された内部空間が形成される。そして、この内部空間内に緩衝部材１５の全部が収納されることとなる。このとき、緩衝部材１５の主弾性塊部１５１の端部両面側に設けられた弾性突起１５４によって、円筒樹脂部材１４は収納ケース１８に対して軸方向（スラスト方向）に弾性的に支承された状態となる。この弾性突起１５４は半球状をしていて、壁面と略点接触状態となるため、円筒樹脂部材１４の収納ケース１８に対する回動はほとんど妨げられず、弾性突起１５４の摩耗や劣化等も少ない。また、円筒樹脂部材１４は周方向の均等な３カ所で弾性突起１５４により支承されるため、非常に安定した姿勢を保つ。従って、インターナルギヤ１４９の傾き等による駆動力の伝達ロスやその摩耗等を十分に抑制、低減できる。
【００３８】
次に、スタータＳによるエンジン始動開始前後における円筒樹脂部材１４、緩衝部材１５および収納ケース１８の作動について図７を用いて説明する。図７（ａ）、（ｂ）はそれぞれスタータＳの作動前後の様子を平面的に展開した断面図である。
図７（ａ）からも明らかなように、スタータＳの作動前には、収納ケース１８の不動係止突起１８１および不動当接突起１８２と円筒樹脂部材１４の可動係止突起１４１とによって形成された空間（主不動凹部１８３）に緩衝部材１５が弾性圧縮された状態で嵌入されている。また、その緩衝部材１５の前後周方向では、その不動係止突起１８１とそれに隣接した別の不動当接突起１８２との間の空間（副不動凹部１８４）に円筒樹脂部材１４の可動当接突起１４２が遊嵌されている。そして、スタータＳの作動前、緩衝部材１５は取付時の予圧縮量を除いて実質的に圧縮されておらず、可動当接突起１４２も不動当接突起１８２から離れた位置つまり不動係止突起１８１側にある。
【００３９】
一方、スタータＳが作動を開始すると、円筒樹脂部材１４はインターナルギヤ１４９から図の矢印方向（図上方）へ反力を受ける。この反力によって、その可動係止突起１４１は緩衝部材１５の主弾性塊部１５１をその反力方向へ圧縮する。本実施形態では、スタータＳの作動前から可動係止突起１４１と主弾性塊部１５１とが弾性密着した状態となっているため、円筒樹脂部材１４に作用する反力は可動係止突起１４１を介して主弾性塊部１５１で当初から穏やかに吸収され、急激な衝撃荷重等が作用することもない。なお、この圧縮動作の際、緩衝部材１５および可動係止突起１４１は、主不動凹部１８３が案内溝の機能を果し、それによってガイドされる。また、可動当接突起１４２は、副不動凹部１８４が案内溝の機能を果し、それによってガイドされる。
【００４０】
上記反力がさらに大きくなり、可動係止突起１４１による主弾性塊部１５１の圧縮量が限界付近（例えば、圧縮量３０％）に達すると、その可動係止突起１４１と一体的に回転する可動当接突起１４２が固定された収納ケース１８の不動当接突起１８２に当接する（図７（ｂ）の状態）。すると、これ以降、円筒樹脂部材１４は反力方向に回転できず、可動係止突起１４１によって主弾性塊部１５１の圧縮量が上記限界圧縮量（最大圧縮量）を超えないようになっている。
【００４１】
なお、エンジン始動後等に円筒樹脂部材１４に作用していた反力が解放されると、緩衝部材１５および円筒樹脂部材１４は図７（ｂ）の状態から図７（ａ）の状態へ戻る。このとき、可動係止突起１４１は別の不動当接突起１８２（図７の下側にある不動当接突起１８２）に向って逆回転（復帰）するが、そもそも作用している力が弱く、さらには両者間に副弾性塊部１５２も存在するため、その際に各部に衝撃荷重等が加わったりその周囲で不快音等が発生することはほとんどない。
【００４２】
このように、本実施形態のスタータＳは、その作動時の反力を緩衝部材１５によって緩和しつつ受止めると共に緩衝部材１５の損傷等をも防止し、静粛であると共に信頼性の高いものとなっている。そして、樹脂製のインターナルギヤ１４９を使用した場合でも、十分な信頼性が確保されている。
【図面の簡単な説明】
【図１】本発明に係る実施形態であるスタータの全体を示す要部断面図である。
【図２】その始動装置に用いた円筒樹脂部材を示す斜視図である。
【図３】その始動装置に用いた緩衝部材を示す斜視図である。
【図４】その始動装置に用いた収納ケースを示す斜視図である。
【図５】その円筒樹脂部材、緩衝部材および収納ケースの配置を示す分解斜視図である。
【図６】円筒樹脂部材に緩衝部材を組込んだ様子を示す斜視図である。
【図７】円筒樹脂部材、緩衝部材および収納ケースの作動を示す平面展開図であり、同図（ａ）はスタータの作動前を示し同図（ｂ）スタータの作動中を示す。
【符号の説明】
Ｓ始動装置
１０減速機
１１サンギヤ
１２プラネタリギヤ
１３キャリア
１４円筒樹脂部材
１４１可動係止突起
１４２可動当接突起
１４９インターナルギヤ
１５緩衝部材
１５１主弾性塊部
１５２副弾性塊部
１５３架橋部
１５４弾性突起
１８収納ケース
１８１不動係止突起
１８２不動当接突起[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starting device used when starting an engine. More specifically, the present invention relates to a starting device including a reduction gear using a planetary gear.
[0002]
[Prior art]
An internal combustion engine (hereinafter simply referred to as “engine”) requires rotational driving by a starter (hereinafter referred to as “starter” as appropriate) upon starting. The starter includes a gear type starter and the like, all of which are common in that an electric motor (hereinafter simply referred to as “motor”) is a drive source. A relatively large torque is required to start the engine, although it depends on the type and displacement. For this reason, if the engine is directly cranked by the motor, the physique of the motor naturally increases. Therefore, in a recent starter that is required to be lightweight and compact, a high speed required for starting is obtained by interposing a reduction gear between the motor and the engine and increasing the reduction ratio.
[0003]
Although there are various types of reduction gears, planetary gear type reduction gears that are compact and provide a large reduction ratio are frequently used. In this reduction device, the driving force input from the motor to the sun gear is output with high torque from the carrier that supports the planetary gear. As a premise, a large reaction force (torque) generated according to the output must be received by the internal gear. That is, the internal gear needs to be restricted from rotating in the circumferential direction.
[0004]
By the way, the torque required for rotation of the engine suddenly fluctuates by processes such as intake and compression, and the rotation speed also pulsates. Since the starter motor cannot skillfully follow such load fluctuations, the reaction force acting on the internal gear is not constant. As a result, if the internal gear is simply restrained, an unpleasant noise may be generated when starting the engine due to vibration of the internal gear or the like.
Therefore, in order to alleviate and absorb load fluctuations acting on the internal gear and the like, a buffer member made of an elastic body such as rubber is disposed between the internal gear and its restraining portion. . Such a disclosure is disclosed in Patent Document 1 below, for example.
[0005]
[Patent Document 1]
JP-A-5-52166
[0006]
[Problems to be solved by the invention]
In Patent Document 1, since the protrusion extending in the axial direction from the side surface of the internal gear is held by the buffer member (elastic body), the starter is not enlarged in the outer diameter direction. However, in this case, the friction plate is separately pressed by the rotating plate engaged with the internal gear, and the internal gear is restrained by the frictional force generated therebetween. For this reason, the structure of the starting device is complicated. Moreover, the buffer member used in Patent Document 4 is a substantially rectangular parallelepiped rubber and has a large contact area with the inner wall of the storage portion. For this reason, the compression operability of the buffer member is not good, wear and the like are likely to occur, and it is difficult to improve reliability. Moreover, the buffer member only receives the reaction force in the circumferential direction of the internal gear, and the support in the axial direction is not specifically disclosed.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a starter capable of eliminating the unpleasant noise at the start and improving the durability and overall reliability of the buffer member. And
[0008]
[Means for Solving the Problems and Effects of the Invention]
Therefore, the present inventor has intensively studied to solve this problem, and as a result of repeated trial and error, the buffer member is disposed not in the outer peripheral side of the internal gear but in the axial direction thereof, and in the axial direction of the buffer member. The inventors came up with the idea of providing an elastic protrusion on the side and completed the present invention.
That is, the starting device of the present invention includes a drive motor, a sun gear that rotates by receiving an input from the drive motor, an internal gear that is disposed concentrically with the sun gear on the outer peripheral side of the sun gear, the sun gear, and the interface. A planetary gear meshing with a null gear, a planetary gear that rotatably supports the planetary gear, and a carrier that decelerates and outputs the input of the sun gear and a rotation constraint that restrains rotation of the internal gear that is arranged in a circumferentially movable state A starting device for starting and rotating the engine via the speed reducer,
The rotation restraining means is provided on the internal gear, and is configured to move integrally with the internal gear. The rotational locking means is opposed to the movable locking portion, and is circumferential with the movable locking portion. And a stationary locking portion disposed in a stationary state in the circumferential direction, and elastically held between at least the movable locking portion and the stationary locking portion, and the drive motor is interposed via the speed reducer. An elastic lump that elastically receives a reaction acting on the internal gear when the engine is started and rotated, and protrudes from at least one of the elastic lump on the axial direction side to elastically hold the internal gear in the axial direction. And a shock-absorbing member having an elastic protrusion.
[0009]
In the case of the starter of the present invention, the rotation of the internal gear of the speed reducer to at least one is restricted by the rotation restricting means including the movable locking portion, the non-moving locking portion, and the buffer member.
Next, when starting the engine by the starter, the internal gear receives a reaction force (torque in the opposite direction) in the direction opposite to the output from the carrier. This reaction force is received from the movable locking portion that rotates integrally with the internal gear by the stationary locking portion via the elastic mass portion of the buffer member, and the internal gear is restrained from rotating in the reaction force direction. The Here, the reaction force acting on the internal gear is elastically and gently received by the stationary locking portion due to the presence of the elastic mass portion. Therefore, a shocking load is not applied to each part, and unpleasant noise due to direct contact between the locking members does not occur. Moreover, since this buffer member also plays the role of what is called a vibration isolator, it can also absorb the vibration and sound which generate | occur | produce around a reduction gear and its periphery. Thus, the speed reducer of the present invention has a relatively simple structure, but can sufficiently reduce vibrations, unpleasant sounds, and the like that are generated when the starter is operated.
[0010]
By the way, the buffer member of this invention has the elastic protrusion which protruded from at least one of the axial direction side in addition to the said elastic mass part. The elastic protrusion elastically holds the internal gear in the axial direction. That is, first, the elastic protrusion functions as a thrust bearing of an internal gear. Further, since vibration and vibration of the internal gear are suppressed, stable deceleration output can be obtained without causing wear of the internal gear.
Moreover, since this elastic protrusion protrudes from the end surface etc. of the axial direction side of an elastic lump part, the contact area with the sliding wall surface in the axial direction side of a buffer member becomes very small. For this reason, compared with the case where the side surface on the axial direction side of the elastic mass portion is entirely in sliding contact with the wall surface of the case housing the elastic mass portion, the movement of the elastic mass portion during the compression operation becomes very smooth. . In addition, since the elastic projection mainly comes into sliding contact with the sliding wall surface or the like, the elastic mass portion itself hardly undergoes wear or deterioration, and the reliability of the buffer member can be improved.
[0011]
Further, it is preferable that the elastic protrusion is provided on the side of the stationary locking portion of the elastic mass portion (Claim 2).
As a result, the elastic protrusion itself hardly slides and wear of the elastic protrusion as well as the elastic mass part is suppressed, and the reliability of the buffer member and the reliability of the starting device is further improved. In addition, by providing the elastic protrusion, the rigidity of the elastic mass portion in the vicinity thereof is improved, and it is possible to suppress inadvertent deformation of the elastic mass portion compressed during the operation of the starter, etc. Reliability can be improved.
[0012]
The rotation restraining means further includes a movable contact portion that is disposed at a predetermined interval from the movable locking portion and rotates integrally with the movable locking portion, and an axial direction facing the movable contact portion. And the movable abutting portion and a stationary abutting portion that is disposed in a circumferentially stationary state in opposition to the movable abutting portion, and the elastic mass formed by the movable locking portion and the immovable locking portion. It is preferable that the amount of compression of the portion can be limited by the contact between the movable contact portion and the non-moving contact portion.
[0013]
In this case, even when a large reaction force acts on the internal gear, the rotation is limited to a range until the movable contact portion and the non-moving contact portion contact each other. Therefore, the compression amount of the elastic mass portion by the movable locking portion and the non-moving locking portion is also limited within a predetermined range. Thereby, breakage, damage, early fatigue, etc. of the buffer member due to excessive compression can be prevented in advance. And the reliability of a buffer member and by extension, the reliability of a starting device improves. Further, even when a large reaction force acts on the internal gear, the movable contact portion and the non-moving contact portion act as a so-called detent and the rotation is restricted, so that the input from the drive motor is efficient. Decelerated and output from carrier.
[0014]
In the starting device of the present invention, since the movable locking portion and the non-moving locking portion are elastically held by the elastic mass portion, the load applied to the movable locking portion is elastic from the beginning of operation of the starting device and is moderate. It is. In addition, even when the elastic mass portion returns after the engine is started, the force applied to the movable locking portion is moderate. Here, the state in which the elastic mass portion is elastically held between the movable locking portion and the non-moving locking portion is, for example, a little compression of the substantially elastic lump-shaped buffer member, It is obtained by incorporating it between the parts.
In this way, a reliable and highly efficient starting device in which unpleasant noise is suppressed can be obtained. Moreover, since the compression amount (maximum compression amount) allowed for the elastic mass portion can be easily changed by adjusting the distance between the movable contact portion and the non-moving contact portion, the degree of freedom in designing the speed reducer is also improved. large.
[0015]
By the way, as the buffer member, various types such as a spring, a synthetic resin, and a synthetic rubber can be considered. However, when the buffer member is made of synthetic rubber as in the present invention, the degree of freedom in shape is large, and performance, reliability, cost, assembly, etc. Is preferable. In particular, when the elastic mass portion is made of synthetic rubber, it is preferable to dispose the movable contact portion and the non-moving contact portion so that the maximum compression rate of the elastic mass portion is 10 to 30%. ).
[0016]
The general allowable maximum compression rate of synthetic rubber is usually said to be around 20% in consideration of durability, but those that are used only for a short time at the start, such as the elastic mass part of the present invention, Even if the compression rate exceeds 20%, its reliability is not impaired for a long time. However, if the compression ratio exceeds 30%, it is not preferable because breakage or damage of the elastic mass portion or the like may be caused. Therefore, in the case of the present invention, the compression ratio is kept within 30%. In addition, since the movable contact part and the non-moving contact part are provided, it is easy to limit the upper limit of the compression rate. The reason why the lower limit of the compression ratio is set to 10% is to effectively use the elasticity of the elastic mass.
[0017]
So far, the case where the elastic mass portion is compressed by the movable locking portion has been mainly described. However, the direction of the force acting on the movable locking portion changes before and after the engine is started. For this reason, a movable latching | locking part and by extension, an internal gear can rotate to the reverse direction to the reaction force direction. Although it may be slight also at this time, a vibration and an unpleasant noise may be generated with a reduction gear. It is preferable to reduce such vibrations and unpleasant sounds.
[0018]
Therefore, the buffer member includes a main elastic mass portion that forms the elastic mass portion, a secondary elastic mass portion that is elastically held between the movable locking portion and the non-moving contact portion, and the movable locking portion. It is preferable that the circumferential length ratio of the main elastic mass portion to the secondary elastic mass portion is 4 to 6 with a bridging portion that bridges the main elastic mass portion and the secondary elastic mass portion. (Claim 5).
Thereby, the movable locking portion is elastically held also on the back side of the main elastic lump portion by the sub elastic lump portion. As a result, the movable locking portion and thus the internal gear are elastically held in any rotational direction. Therefore, the movable locking portion is more stably held, and unpleasant noise generated by the speed reducer can be significantly reduced. Moreover, since the main elastic lump part and the subelastic lump part are connected by the bridge | crosslinking part, an assembly | attachment and component management become very easy.
[0019]
Here, the reason why the circumferential length ratio of the main elastic mass portion to the sub-elastic mass portion is 4 to 6 is that a larger force (that is, a reaction force at the start) acts in the compression direction of the main elastic mass portion, This is because the force acting in the compression direction (opposite to the reaction force) of the sub-elastic mass is not so large. This is because if the circumferential length ratio is less than 4, it is difficult to ensure the durability of the main elastic mass portion. Conversely, if the circumferential length ratio exceeds 6, it is difficult to achieve compactness. In addition, what is necessary is just to compare the circumferential direction length ratio by the center circular arc length of a main elastic lump part and a subelastic lump part.
The elastic mass portion (or main elastic mass portion) is preferably such that the substantially central portion in the circumferential direction is narrower than the end portion and can be contracted in the circumferential direction (Claim 6).
[0020]
In the case of the present invention, in order for the buffer member to gently absorb the reaction force acting on the internal gear, the elastic mass portion needs to be easily deformed. Therefore, when the central portion of the elastic mass portion is constricted as described above, the deformation resistance is reduced at least in the central portion. Further, when the elastic mass portion is compressed, the constricted portion expands to the surroundings and causes a shape change accompanying the compression at the portion, so that the elasticity of the elastic mass portion is effectively used. Thus, by providing the constricted portion at substantially the center, a shock absorbing member having a large impact absorbing ability can be obtained. In addition, since the said elastic mass part is not constricted in an edge part conversely, in the both ends, it is stably hold | maintained at a movable latching | locking part and a fixed latching | locking part.
[0021]
In the case of the present invention, the form and quantity of the buffer member to be arranged are not particularly limited, but in order to ensure a compact starter and a stable operation of the internal gear, buffer members are provided at three or more locations in the circumferential direction. It is preferable to arrange them equally. Therefore, it is preferable that the movable locking portion, the movable contact portion, the immovable locking portion, and the non-moving contact portion are each equally disposed in three or more pairs in the circumferential direction. ). Similarly, it is preferable that the movable contact portion and the non-moving contact portion are equally disposed in the circumferential direction in three pairs or more (Claim 8).
[0022]
Thereby, the inclination and bias of the internal gear at the start of starting can be suppressed, and the smooth operation of the starting device is ensured. Further, since the reaction force and the like at the start of starting can be received by the plurality of elastic mass portions, the shock absorbing member can be downsized and a stable shock absorbing ability can be obtained.
In addition, when providing a buffer member in multiple places, it is preferable at points, such as component management and an assembly, if it is integrated in cyclic | annular form. However, for example, it is more preferable to assemble the main elastic mass portion, the sub elastic mass portion, the cross-linking portion, and the like by using a plurality of them. This is because it is possible to improve the reliability of the buffer member by preventing dragging between the buffer members accompanying the compression of the main elastic mass portion.
[0023]
By the way, even if the said movable latching | locking part and a movable contact part rotate integrally with an internal gear, both do not necessarily need to be integral. For example, the internal gear, the movable locking portion, and the movable contact portion may be configured as separate members, and may be in a locking relationship such that both rotate integrally.
However, it is preferable to integrate them so that parts management and assembly become easy. Even complicated shapes can be obtained relatively easily and at low cost by resin integral molding.
[0024]
Therefore, the internal gear, the movable locking portion, and the movable contact portion are formed of a resin-molded substantially bottomed cylindrical resin member, and the internal gear is formed on the cylindrical inner peripheral surface of the resin member. Preferably, the movable locking portion and the movable contact portion are a movable locking projection and a movable contact projection that protrude in the axial direction from the outer bottom surface of the resin member, respectively (claim 9).
In the case of the present invention, the reaction force acting on the internal gear and the movable locking part is sufficiently shock-absorbed by the buffer member, so that even if they are integrally molded with resin, breakage, damage, etc. No wear, excellent wear resistance, etc., and high reliability.
[0025]
However, the stationary locking portion and the stationary contact portion whose rotation is constrained need to be provided separately as the following case or the like independently of the resin member or the like.
That is, the stationary locking portion and the stationary contact portion are each a stationary locking projection that protrudes in the axial direction from the bottom surface of the substantially bottomed cylindrical case that faces the outside of the bottom surface of the resin member and whose rotation is restricted. It is preferable that the buffer member is housed in a recess provided inside the cylinder of the case.
[0026]
Note that the term “immobility” as used with respect to the immovable locking portion and the immovable contact portion means that the immovable locking portion and the immovable contact portion do not substantially rotate, and there is no problem with some backlash or the like. The starting device of the present invention is not limited to a gear type starter, and may be another type of starter. Furthermore, the “circumferential direction” or “axial direction” in the present specification refers to the rotation center axis of the speed reducer.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail with reference to embodiments.
(First embodiment)
FIG. 1 shows a gear type starter (hereinafter simply referred to as “starter”) S which is an embodiment of the starting device of the present invention. The starter S mainly includes a speed reducer 10, a motor 80, and a magnet switch 90. The output of the motor 80 is transmitted via the speed reducer 10 from a carrier 13 described later to an output shaft having a helical spline formed on the outer peripheral surface. An overrunning clutch (one-way clutch) 82 and a pinion gear 83 are arranged on the helical spline. The overrunning clutch 82 and the pinion gear 83 are pushed out in the axial direction (to the left in FIG. 1) by lever operation by the magnet switch 90 at the time of starting. The pinion gear 83 temporarily meshes with a ring gear attached to the crankshaft of the engine, and cranks the engine. When the engine is started, the overrunning clutch 82 causes the pinion gear 83 of the starter S to idle so that the motor 80 is prevented from over-rotating.
[0028]
By the way, the speed reducer 10 supports the sun gear 11 formed on the motor main shaft 81 extending from the motor 80, the three planetary gears 12 disposed around the sun gear 11 and meshing with the sun gear 11, and the planetary gear 12 so as to be able to rotate and revolve. Carrier 13, a cylindrical resin member 14 provided on the inner surface of the planetary gear 12, which is disposed on the outer peripheral side of the planetary gear 12 and meshes with the planetary gear 12, and an axially forward side of the cylindrical resin member 14 (see FIG. 1). A storage case 18 (case) provided on the left side) and a buffer member 15 interposed between the cylindrical resin member 14 and the storage case 18. A cover plate 19 is provided on the rear end surface in the axial direction of the cylindrical resin member 14 to close the front portion of the motor housing of the motor 80 and to restrict the movement of the cylindrical resin member 14 to the rear side of the shaft.
[0029]
Next, the rotation restraining means comprising the cylindrical resin member 14, the buffer member 15, and the storage case 18, which is a characteristic part of the present embodiment, will be described.
The cylindrical resin member 14 has a substantially bottomed cylindrical shape as shown in FIG. 2 and is integrally formed of a thermoplastic resin. The internal gear 149 is also integrally formed on a cylindrical inner surface located rearward (right side in the figure). On the annular bottom surface in front of the cylindrical resin member 14, three pairs of movable locking projections 141 and movable contact projections 142 that project forward in the axial direction are provided radially and equally. The thickness of the movable contact projection 142 is larger than the thickness of the movable locking projection 141 so that a large reaction force can be received stably.
[0030]
The cylindrical resin member 14 includes an inner annular protrusion 145 and an outer annular protrusion 146 that slightly protrude forward from the inner peripheral side and the outer peripheral side of the bottom surface. Then, the main movable concave portion 143 and the sub movable concave portion 144 which are slightly depressed are alternately formed by the movable locking projection 141 and the movable contact projection 142. The circumferential length ratio of the main movable concave portion 143 and the sub movable concave portion 144 can be easily adjusted depending on where the movable locking projection 141 is disposed between the adjacent movable contact projections 142.
[0031]
As shown in FIG. 3, the buffer member 15 is integrally formed with a main elastic mass portion 151, a secondary elastic mass portion 152, and a bridging portion 153 that bridges and connects both of them, and is made of oil-resistant synthetic rubber (NBR or the like). It is a thing. Here, the oil-resistant synthetic rubber is used in order to maintain the function of the buffer member 15 for a long period of time without deterioration even when grease used for reducing sliding resistance adheres. It is.
[0032]
The main elastic block 151 has a fan-shaped block shape and is in a state where the periphery of the substantially central portion is constricted. In addition, hemispherical elastic protrusions 154 (elastic protrusions) are provided on both sides on the outer peripheral end side of the main elastic mass 151 in contact with the storage case 18. The sub-elastic mass 152 is also a fan-shaped block, but its circumferential length is considerably shorter than the main elastic mass 151. In the present embodiment, the circumferential length ratio between the main elastic mass 151 and the secondary elastic mass 152 is about 5: 1. The bridging portion 153 connects the inner end portions of the main elastic lump portion 151 and the sub elastic lump portion 152 in a band shape.
[0033]
The storage case 18 has a substantially disk shape as shown in FIG. 4 and is obtained by appropriately cutting an aluminum alloy casting. The front (left side in the figure) of the storage case 18 is formed in a substantially flat plate shape, but on the back side (right side in the figure), there are three pairs of fixed locking protrusions 181 and fixed contact protrusions 182 protruding rearward in the axial direction. Radially and evenly provided. The thickness of the stationary contact projection 182 is thicker than the thickness of the stationary locking projection 181 so that a large reaction force can be received stably.
[0034]
Further, the storage case 18 includes an inner annular protrusion 185 and an outer annular protrusion 186 that protrude rearward from the inner peripheral side and the outer peripheral side on the back side. The main stationary recess 183 and the secondary stationary recess 184 that are recessed are alternately formed by the stationary locking projection 181 and the stationary contact projection 182. The circumferential length ratio of the main immovable recess 183 and the auxiliary immovable recess 184 can be easily adjusted depending on which of the immovable locking projections 181 is disposed between the adjacent immovable contact projections 182.
The storage case 18 has a locking piece 189 on the outer periphery. The locking piece 189 engages with the housing of the starter S (not shown) and is restrained so that the storage case 18 does not rotate in the circumferential direction.
[0035]
Next, assembly of the cylindrical resin member 14, the buffer member 15, and the storage case 18 will be described with reference to FIGS. FIG. 5 shows an exploded view of the three parties, and FIG. 6 shows a state in which the buffer member 15 is assembled to the cylindrical resin member 14. 6 shows a state in which the buffer member 15 is assembled to the cylindrical resin member 14 for the sake of convenience. Actually, the cylindrical resin member 14 is assembled after the buffer member 15 is assembled to the storage case 18. . Based on this, it will be described below.
[0036]
First, the buffer member 15 is assembled to the storage case 18. At this time, the buffer member 15 is assembled so as to be fitted between the stationary locking projection 181 and the stationary contact projection 182 of the storage case 18. Then, the movable locking projection 141 formed on the cylindrical resin member 14 is assembled so as to be pushed between the main elastic mass portion 151 and the sub elastic mass portion 152 of the buffer member 15. Thereby, the main elastic mass portion 151 and the sub elastic mass portion 152 are in a state of elastically holding the movable locking protrusion 141. Assembly of the buffer member 15 and the cylindrical resin member 14 is performed at three locations in the circumferential direction. As a result, the immovable locking projection 181 is almost sandwiched between the movable contact projection 142 of the cylindrical resin member 14 and the main elastic mass portion 151 of the buffer member 15. On the other hand, the non-moving contact protrusion 182 is in a state in which the secondary elastic mass 152 of the buffer member 15 is elastically sandwiched between it and the movable locking protrusion 141 of the cylindrical resin member 14.
[0037]
The inner annular projection 145 and the outer annular projection 146 of the cylindrical resin member 14 and the inner annular projection 185 and the outer annular projection 186 of the storage case 18 are formed so as to correspond to each other. A substantially secret internal space is formed by the storage case 18. And all of the buffer member 15 will be accommodated in this internal space. At this time, the cylindrical resin member 14 was elastically supported in the axial direction (thrust direction) with respect to the storage case 18 by the elastic projections 154 provided on both end sides of the main elastic mass portion 151 of the buffer member 15. It becomes a state. Since the elastic protrusion 154 is hemispherical and is in a substantially point contact state with the wall surface, the rotation of the cylindrical resin member 14 with respect to the storage case 18 is hardly hindered, and the elastic protrusion 154 is less worn and deteriorated. Further, since the cylindrical resin member 14 is supported by the elastic protrusions 154 at three equal positions in the circumferential direction, it maintains a very stable posture. Therefore, it is possible to sufficiently suppress and reduce the transmission loss of the driving force due to the inclination of the internal gear 149 and the wear thereof.
[0038]
Next, operations of the cylindrical resin member 14, the buffer member 15, and the storage case 18 before and after the start of the engine start by the starter S will be described with reference to FIG. FIGS. 7A and 7B are cross-sectional views in which the state before and after the starter S is operated is two-dimensionally developed.
As apparent from FIG. 7A, before the starter S is actuated, it is formed by the immovable locking projection 181 and the immovable abutting projection 182 of the storage case 18 and the movable locking projection 141 of the cylindrical resin member 14. The buffer member 15 is fitted into the space (main immovable recess 183) in an elastically compressed state. Further, in the front-rear circumferential direction of the buffer member 15, the movable contact protrusion of the cylindrical resin member 14 is inserted into a space (sub-removable recess 184) between the fixed locking protrusion 181 and another fixed contact protrusion 182 adjacent thereto. 142 is loosely fitted. Before the starter S is actuated, the buffer member 15 is not substantially compressed except for the pre-compression amount at the time of attachment, and the movable contact protrusion 142 is also away from the fixed contact protrusion 182, that is, the fixed locking protrusion. 181 side.
[0039]
On the other hand, when the starter S starts operating, the cylindrical resin member 14 receives a reaction force from the internal gear 149 in the direction of the arrow in the figure (upward in the figure). Due to this reaction force, the movable locking projection 141 compresses the main elastic mass 151 of the buffer member 15 in the reaction force direction. In the present embodiment, since the movable locking projection 141 and the main elastic mass portion 151 are in elastic contact before the starter S is actuated, the reaction force acting on the cylindrical resin member 14 causes the movable locking projection 141 to move. Accordingly, the main elastic mass 151 is gently absorbed from the beginning, and a sudden impact load or the like does not act. During this compression operation, the buffer member 15 and the movable locking projection 141 are guided by the main immovable recess 183 serving as a guide groove. Further, the movable abutment protrusion 142 is guided by the auxiliary immovable recess 184 serving as a guide groove.
[0040]
When the reaction force is further increased and the amount of compression of the main elastic mass portion 151 by the movable locking projection 141 reaches a limit (for example, 30% compression), the movable locking projection 141 rotates integrally with the movable locking projection 141. The contact protrusion 142 contacts the stationary contact protrusion 182 of the storage case 18 to which the contact protrusion 142 is fixed (the state shown in FIG. 7B). Thereafter, the cylindrical resin member 14 cannot rotate in the reaction force direction, and the compression amount of the main elastic mass portion 151 does not exceed the above limit compression amount (maximum compression amount) by the movable locking projection 141. .
[0041]
When the reaction force acting on the cylindrical resin member 14 after the engine is started is released, the buffer member 15 and the cylindrical resin member 14 return from the state shown in FIG. 7B to the state shown in FIG. 7A. . At this time, the movable locking projection 141 rotates backward (returns) toward another stationary contact projection 182 (the stationary contact projection 182 on the lower side of FIG. 7), but the acting force is weak in the first place. Furthermore, since there is also a secondary elastic mass portion 152 between them, an impact load or the like is not applied to each portion at that time, and unpleasant noise or the like is hardly generated around the portion.
[0042]
As described above, the starter S of the present embodiment receives the reaction force during operation by the buffer member 15 while relaxing the buffer member 15 and prevents damage to the buffer member 15, etc., and is quiet and highly reliable. It has become. Even when the resin internal gear 149 is used, sufficient reliability is ensured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing an entire starter according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a cylindrical resin member used in the starting device.
FIG. 3 is a perspective view showing a buffer member used in the starting device.
FIG. 4 is a perspective view showing a storage case used in the starting device.
FIG. 5 is an exploded perspective view showing the arrangement of the cylindrical resin member, the buffer member, and the storage case.
FIG. 6 is a perspective view showing a state in which a buffer member is incorporated in a cylindrical resin member.
FIG. 7 is a developed plan view showing the operation of the cylindrical resin member, the buffer member and the storage case. FIG. 7 (a) shows the starter before operation, and FIG. 7 (b) shows the starter in operation.
[Explanation of symbols]
S starter
10 Reducer
11 Sungear
12 Planetary gear
13 Career
14 Cylindrical resin material
141 Movable locking projection
142 Movable contact protrusion
149 Internal gear
15 cushioning member
151 Main elastic mass
152 Secondary elastic mass
153 Crosslinked part
154 Elastic protrusion
18 Storage case
181 Fixed locking projection
182 Immovable contact protrusion

Claims

A drive motor;
A sun gear that rotates in response to an input from the drive motor, an internal gear that is disposed concentrically with the sun gear on the outer peripheral side of the sun gear, a planetary gear that meshes with the sun gear and the internal gear, and the planetary gear that is rotatable. A drive motor comprising: a carrier that supports and decelerates and outputs an input of the sun gear; and a speed reducer having a rotation restraining means that restrains rotation of the internal gear arranged in a movable state in the circumferential direction. In the starting device for starting and rotating the engine via the speed reducer,
The rotation restraining means is
A movable locking portion provided on the internal gear and rotating integrally with the internal gear;
An immovable locking portion that faces the movable locking portion and is arranged in a circumferentially opposed state to the movable locking portion;
Elastically received at least between the movable locking portion and the non-moving locking portion and elastically receiving a reaction that acts on the internal gear when the drive motor starts and rotates the engine via the speed reducer. And a shock-absorbing member that protrudes from at least one of the elastic mass portions in the axial direction and elastically holds the internal gear in the axial direction.

The starting device according to claim 1, wherein the elastic protrusion is provided on the stationary locking portion side of the elastic mass portion.

The rotation restraining means is further provided with a movable contact portion that is disposed at a predetermined interval from the movable locking portion and rotates integrally with the movable locking portion;
The movable abutting portion extends in the axial direction facing the movable abutting portion, and has a stationary abutting portion disposed in a circumferentially opposed state against the movable abutting portion,
The starting device according to claim 1, wherein the amount of compression of the elastic mass portion by the movable locking portion and the non-moving locking portion can be limited by contact between the movable contact portion and the non-moving contact portion.

The elastic mass portion is made of synthetic rubber,
The starter according to claim 3, wherein the movable contact portion and the non-moving contact portion are disposed at a position where the maximum compression rate of the elastic mass portion is 10 to 30%.

The buffer member includes a main elastic mass portion that forms the elastic mass portion, a secondary elastic mass portion that is elastically held between the movable locking portion and the non-moving contact portion, and straddles the movable locking portion. And having a bridging portion for bridging the main elastic mass portion and the secondary elastic mass portion,
The starting device according to claim 3, wherein a circumferential length ratio of the main elastic mass portion to the sub elastic mass portion is 4 to 6.

The starter according to claim 1, wherein the elastic lump portion is narrower at a substantially central portion in the circumferential direction than the end portion and can be contracted in the circumferential direction.

The starter according to claim 1, wherein the movable locking portion and the stationary locking portion are equally disposed in the circumferential direction in three or more pairs.

4. The starter according to claim 3, wherein the movable contact portion and the non-moving contact portion are equally arranged in three or more pairs in the circumferential direction.

The internal gear, the movable locking portion, and the movable contact portion are made of a substantially bottomed cylindrical resin member integrally molded with resin,
The internal gear is composed of internal teeth formed on the cylindrical inner peripheral surface of the resin member,
The starter according to claim 3, wherein the movable locking portion and the movable contact portion include a movable locking protrusion and a movable contact protrusion that protrude in the axial direction from the outer bottom surface of the resin member, respectively.

The immovable locking portion and the immovable contact portion are respectively an immovable locking projection and an immobile protruding in the axial direction from the bottom surface of the substantially bottomed cylindrical case whose rotation is restricted facing the outer bottom surface of the resin member. A contact protrusion,
The starting device according to claim 9, wherein the buffer member is housed in a recess provided inside the cylinder of the case.