JP3954910B2

JP3954910B2 - Check valve for hydraulic continuously variable transmission

Info

Publication number: JP3954910B2
Application number: JP2002181349A
Authority: JP
Inventors: 豪朗野崎; 安久望月; 謙悟笹原
Original assignee: Yanmar Co Ltd
Current assignee: Yanmar Co Ltd
Priority date: 2002-06-21
Filing date: 2002-06-21
Publication date: 2007-08-08
Anticipated expiration: 2022-06-21
Also published as: JP2004028131A

Description

【０００１】
【発明の属する技術分野】
本発明は、油圧ポンプと油圧モータとで構成され一対のメイン油路を備える油圧式無段変速機を、同一の油路板に２つ配置した構成における、メイン油路とチャージ回路との間に設けられるチェックバルブの構成に関する。
【０００２】
【従来の技術】
従来から、油圧ポンプと油圧モータとで構成され、一対のメイン油路を有する油圧式無段変速機（以下ＨＳＴ式変速機）においては、例えば、図７に示すように、油路板３２に形成された各メイン回路３２ｍ・３２ｍとチャージ回路３２ｃとの間に、コイルバネ９３ｂによりバルブ部材９３ａを付勢して構成されるチェックバルブ９３が、それぞれ設けられていた。該チェックバルブ９３の各構成部材は、油路板３２の左右端部から内側のチャージ回路側へ、メイン回路３２ｍ・３２ｍと直交する方向に挿入されている。また、バルブ部材９３ａが圧接して、メイン回路３２ｍとチャージ回路３２ｃとの間をシールするためのバルブシート９４が、油路板３２に形成されていた。
【０００３】
【発明が解決しようとする課題】
しかし、２つの油圧式無段変速機を左右に並べて一つの油路板に配置する場合には、前記チェックバルブ９３をメイン回路３２ｍと直交する方向に挿入することができるのは、各油圧式無段変速機の左右外側（油路板３２の左右端部側）に位置するチェックバルブ９３のみで、左右内側（油路板３２の左右中央部側）に位置するチェックバルブ９３をメイン回路３２ｍと直交する方向に挿入することができなくなる。また、チェックバルブ９３をメイン回路３２ｍと直交する方向、即ち左右外側から挿入した場合は、メイン回路３２ｍと直交する方向（上下方向）にしかスペースを確保できない場合等には、チェックバルブ９３のメンテナンスを行うことができなかった。
【０００４】
【課題を解決するための手段】
本発明の解決しようとする課題は以上の如くであり、次に該課題を解決するための手段を説明する。
請求項１においては、２ポンプ２モータ式ＨＳＴ（１）を、油圧ポンプ（１１）および油圧モータ（１２）により構成される第一ＨＳＴ（１０）と、油圧ポンプ（２１）および油圧モータ（２２）により構成される第二ＨＳＴ（２０）により構成し、該第一ＨＳＴ（１０）は車両の走行変速用に、第二ＨＳＴ（２０）は車両の操向旋回用に用い、
該第一ＨＳＴ（１０）の油圧ポンプ（１１）と油圧モータ（１２）、及び第二ＨＳＴ（２０）の油圧ポンプ（２１）と油圧モータ（２２）とを、一枚の油路板（３２）上に配置して構成し、該油圧ポンプ（１１）と油圧モータ（１２）との間を連結する一対のメイン油路（１３ｍ）と、該油圧ポンプ（２１）と油圧モータ（２２）との間を連結する一対のメイン油路（２３ｍ）とを、同一の油路板（３２）に穿設配置し、各ＨＳＴ（１０・２０）のそれぞれのメイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）との間に設けられる油圧式無段変速機のチェックバルブ（３５）において、該チェックバルブ（３５）は、軸方向に貫通孔を有するスリーブ（３６）を、各メイン油路（１３ｍ・２３ｍ）の油路板端面近傍に形成されるバルブ孔（３２ｈ）に、メイン油路（１３ｍ・２３ｍ）方向へ摺動自在に嵌挿し、該バルブ孔（３２ｈ）のスリーブ（３６）より奥側に軸方向に貫通孔を有するシート部材（３７）を嵌装し、該スリーブ（３６）をシート部材（３７）側に付勢する付勢部材（３８）を設けて、該スリーブ（３６）とシート部材（３７）とが当接状態にあるときは、メイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）とが分断され、スリーブ（３６）とシート部材（３７）とが離間状態にあるときはメイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）とが連通されるように構成し、該シート部材（３７）はバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）に着座して、該着座用段差（３２ｄ）への着座部外径をスリーブ（３６）の外径よりも小さく形成し、該スリーブ（３６）は、シート部材（３７）側の小径部（３６ｂ）と油路板端面側の大径部（３６ａ）とを有する段差形状に形成され、該シート部材（３７）の外径をスリーブ（３６）の大径部（３６ａ）の外径と同一又は小さく形成したものである。
【０００５】
請求項２においては、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）の内周に、上端を閉じたピストン部材（５２）を油路板（３２）端面側から摺動自在に挿入し、該スリーブ（３６）の大径部（３６ａ）とピストン部材（５２）との間に両者を離間方向に付勢する付勢部材（３８）を介装し、該シート部材（３７）におけるバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）への着座部外径を、前記ピストン部材（５２）の外径と同一又は小さく形成したものである。
【０００６】
請求項３においては、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）と、バルブ孔（３２ｈ）との間に隙間を設け、該隙間に上端を閉じたピストン部材（５２）を油路板端面側から挿入し、該スリーブ（３６）とシート部材（３７）との間に両者を離間方向に付勢する付勢部材（３８）を介装し、シート部材（３７）におけるバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）への着座部外径をピストン部材（５２）の外径と同一又は小さく形成したものである。
【０００７】
請求項４においては、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）内周に円筒状部材（６２）を嵌装するとともに、該内周に円筒状部材（６２）を嵌装した部分の大径部（３６ａ）の肉厚を、他部よりも薄く形成したものである。
【０００８】
【発明の実施の形態】
次に、本発明の実施の形態を説明する。図１は本発明のチェックバルブが装着される２ポンプ２モータ式ＨＳＴを示す側面断面図、図２は同じく正面断面図、図３はチェックバルブを示す側面断面図、図４はチェックバルブの第二実施例を示す側面断面図、図５はチェックバルブの第三実施例を示す側面断面図、図６はチェックバルブの第四実施例を示す側面断面図、図７は従来のチェックバルブを示す側面断面図である。
【０００９】
本発明のチェックバルブが装着される油圧式無段変速機の概略構成について説明する。図１、図２には、２ポンプ２モータ式の油圧式無段変速機（以降ＨＳＴと記す）１を示しており、２ポンプ２モータ式ＨＳＴ１は、油圧ポンプ１１および油圧モータ１２により構成される第一ＨＳＴ１０と、油圧ポンプ２１および油圧モータ２２により構成される第二ＨＳＴ２０とを、一枚の油路板３２に配置して構成されている。例えば、第一ＨＳＴ１０及び第二ＨＳＴ２０の一方は車両の走行用に、他方は旋回用に用いられている。
【００１０】
第一ＨＳＴ１０を構成する油圧ポンプ１１は、駆動軸１１ａ、該駆動軸１１ａが挿嵌され駆動軸１１ａと共に回動するシリンダブロック１１ｂ、該シリンダブロック１１ｂに摺動自在に挿嵌されたプランジャ１１ｅおよび該プランジャ１１ｅに当接した可動斜板１１ｃにより構成され、可変容量式油圧ポンプに構成されている。可動斜板１１ｃはプランジャ１１ｅの摺動量を規制し、該油圧ポンプ１１の作動油の吐出量を調節可能に構成されている。油路板３２には一対のメイン回路１３ｍ・１３ｍが設けられており、油圧ポンプ１１より作動油が該メイン回路１３ｍを介して油圧モータ１２に供給される。
【００１１】
油圧モータ１２は油圧ポンプ１１と同様に、油路板３２に挿嵌され、その一端をハウジング３１により回動自在に支持された出力軸１２ａ、該出力軸１２ａが挿嵌され駆動軸１２ａと共に回動するシリンダブロック１２ｂ、該シリンダブロック１２ｂに摺動自在に挿嵌されたプランジャ１２ｅおよび該プランジャ１２ｅに当接した固定斜板１２ｃにより構成されている。該シリンダブッロク１２ｂは出力軸１２ａとともに回動する構成になっており、該シリンダブッロク１２ｂにはプランジャ１２ｅが摺動自在に挿嵌されている。該プランジャ１２ｅはハウジング３１に固設された固定斜板１２ｃに当接している。
【００１２】
上記の構成により、駆動力が駆動軸１１ａに入力され、油圧ポンプ１１が駆動される。該油圧ポンプ１１により吐出された作動油は油路板３１を介して油圧モータ１２に供給され、該作動油により油圧モータ１２が駆動され、該駆動力が出力軸１２ａに伝達される。また、第二ＨＳＴ２０を構成する油圧ポンプ２１及び油圧モータ２２も、前記油圧ポンプ１１及び油圧モータ１２と同様に構成されている。
【００１３】
前記油路板３２には、チャージ回路３２ｃが形成されており、該チャージ回路３２ｃと、第一ＨＳＴ１０のメイン回路１３ｍ・１３ｍ、及び第二ＨＳＴ２０のメイン回路２３ｍ・２３ｍとの間には、それぞれチェックバルブ３５が介装されている。そして、各メイン回路１３ｍ・２３ｍの作動油が不足した場合には、チャージ回路３２ｃ３２ｃから該チェックバルブ３５を介して、メイン回路１３ｍ・２３ｍへ作動油が補給されるように構成している。また、チェックバルブ３５は、油路板３２における各メイン回路１３ｍ・２３ｍの上端部に形成されるバルブ孔３２ｈに、油路板３２の上端面からメイン回路１３ｍ・２３ｍ方向（上下方向）に挿入されている。
【００１４】
次に、各メイン回路１３ｍ・２３ｍとチャージ回路３２ｃとの間に設けられるチェックバルブ３５について説明する。図３に示すように、各チェックバルブ３５は、スリーブ３６を、各メイン回路１３ｍ・２３ｍの油路板３２端面近傍に形成されるバルブ孔３２ｈに対して、メイン回路１３ｍ・２３ｍ方向（上下方向）へ摺動自在に嵌挿し、該バルブ孔３２ｈのスリーブ３６より内側（下方）にシート部材３７を嵌装し、該スリーブ３６とバルブ孔３２ｈを上方から塞ぐキャップ３９との間に介装され、該スリーブ３６をシート部材３７側に付勢するコイルバネ３８を設けて構成されている。スリーブ３６は、シート部材３７側の小径部３６ｂと油路板３２端部のキャップ３９側の大径部３６ａとを有する段差形状に形成されており、シート部材３７は、スリーブ３６の小径部３６ｂ先端が当接するシート部３７ｂが形成された円筒状部材にて構成されている。
【００１５】
スリーブ３６がシート部材３７と当接状態にあるときはメイン油路１３ｍ・２３ｍとチャージ回路とが分断され、スリーブ３６とシート部材３７とが離間状態にあるときはメイン油路１３ｍ・２３ｍとチャージ回路３２ｃとが連通されるように構成されている。また、コイルバネ３８が収納されるバネ室３６ｄは、スリーブ３６の小径部３６ｂに形成される連通孔３６ｃ及びシート部３７ｂの連通孔３７ａを通じて、メイン回路１３ｍ・２３ｍと連通しており、メイン回路１３ｍ・２３ｍ内の圧力が、スリーブ３６の閉方向受圧面３６ｅにかかっている。また、スリーブ３６の大径部３６ａと小径部３６ｂとの間に形成される段差部３６ｆには、チャージ回路３２ｃ内の圧力が、スリーブ３６の開方向にかかっている。
【００１６】
そして、閉方向受圧面３６ｅにかかるメイン回路１３ｍ・２３ｍ内の圧力にコイルバネ３８の付勢力を加えた、スリーブ３６の閉方向（スリーブ３６とシート部材３７とが当接する方向）にかかる力が、段差部３６ｆに対してスリーブ３６の開方向（スリーブ３６とシート部材３７とが離間する方向）にかかるチャージ回路３２ｃ内の圧力よりも大きいときには、スリーブ３６はシート部材３７に当接して閉じ、チャージ回路３２ｃとメイン回路１３ｍ・２３ｍとが分断される。一方、閉方向受圧面３６ｅにかかる圧力とコイルバネ３８の付勢力とを加えた力よりも、段差部３６ｆにかかる力の方が大きくなると、スリーブ３６とシート部材３７から離間して開き、チャージ回路３２ｃとメイン回路１３ｍ・２３ｍとが連通する。即ち、各メイン回路１３ｍ・２３ｍの作動油が不足してスリーブ３６の閉方向にかかる力が減少すると、チャージ回路３２ｃ３２ｃから該チェックバルブ３５を介して、メイン回路１３ｍ・２３ｍへ作動油が補給されるように構成されている。
【００１７】
バルブ孔３２ｈとメイン回路１３ｍ・２３ｍとの間には着座用段差３２ｄが形成されており、該着座用段差３２ｄにシート部材３７が着座している。そして、シート部材３７の着座部の径Ｄ２は、該シート部材３７の外径Ｄ３よりも小径に形成され、該シート部材３７の外径Ｄ３は、スリーブ３６の大径部３６ａの外径Ｄ１と同じか小さく形成されている。このように形成することで、シート部材３７にかかる上向きの圧力の受圧面積径Ｄ２の方が、下向きの力の受圧面積径Ｄ１よりも小さくなり、該シート部材３７が上方へ浮き上がることを防止することができる。
【００１８】
以上の如く構成されるチェックバルブ３５は、スリーブ３６やシート部材３７を、メイン回路１３ｍ・２３ｍと同じ方向の上下方向から挿入して構成されているため、２つの第一・第二ＨＳＴ１０・２０を左右に並べて一つの油路板３２に配置する場合であっても、全てのメイン回路１３ｍ・２３ｍに対してチェックバルブ３５を組み込むことができ、第一・第二ＨＳＴ１０・２０の上下方向にしかスペースがない場合でも、該チェックバルブ３５のメンテナンスを容易に行うことが可能となる。また、スリーブ３６が当接するシート部材３７は、油路板３２と別体に形成されて、バルブ孔３２ｈに摺動自在に嵌装されているので、耐磨耗性のある部材を用いることで耐久性を向上することができるとともに、仕組み性や分解性等、メンテナンス性の向上を図ることができる。
【００１９】
次に、チェックバルブ３５の第二実施例について説明する。図４に示すように、チェックバルブ４５は、図３に示したチェックバルブ３５のバネ室３６ｄ内に上端を閉じたピストン４２を上下摺動自在に嵌装し、該ピストン４２とスリーブ３６との間にコイルバネ３８を介装したものである。前述のチェックバルブ３５の場合は、スリーブ３６をバルブ孔３２ｈに対して摺動自在に嵌挿しているため、該スリーブ３６とバルブ孔３２ｈとの間からメイン回路１３ｍ・２３ｍ内の作動油が漏れ出して第一・第二ＨＳＴ１０・２０の効率が低下することとなるが、本例のチェックバルブ４５では、メイン回路１３ｍ・２３ｍ内の作動油が低圧側に漏れだすためには、スリーブ３６とピストン４２との間、及びスリーブ３６とバルブ孔３２ｈとの間の２箇所を通過する必要があるため、作動油の漏れ量を少なくすることができる。また、スリーブ３６及びピストン４２を耐磨耗性がある部材で構成することで、両者間の隙間を長期間に渡って一定に保つことができるので、耐久性も向上することができる。尚、シート部材３７の着座部の径Ｄ２は、ピストン４２の外径Ｄ４と同一径か小径に形成されており、該シート部材３７が上方へ浮き上がることを防止している。
【００２０】
次に、チェックバルブ３５の第三実施例について説明する。図５に示すように、チェックバルブ５５は、図３に示したバルブ孔３２ｈとスリーブ３６の大径部３６ａとの間に、上端を閉じたピストン５２を、上方から上下摺動自在に嵌装し、該ピストン５２とスリーブ３６との間にコイルバネ３８を介装したものである。一般的に、スリーブ３６を嵌挿するバルブ孔３２ｄが形成される油路板３２は、鋳鉄製であるため摩耗しやすく耐久性がさほど高いとはいえない。従って、本例においては、スリーブ３６が摺接するピストン５２の材質を耐磨耗性材料とすることで、該スリーブ３６とピストン５２との間の隙間を長期間一定に保持することができ、耐久性を向上することができる。また、スリーブ３６とピストン５２との間を所定寸法に構成していれば、スリーブ３６を嵌挿するバルブ孔３２ｄの径は多少ラフに形成しても、メイン回路１３ｍ・２３ｍ内の作動油の漏れには影響がないため、バルブ孔３２ｄの加工時間や加工費用を低減することができる。尚、シート部材３７の着座部の径Ｄ２は、ピストン５２の外径Ｄ５と同一径か小径に形成されており、該シート部材３７が上方へ浮き上がることを防止している。
【００２１】
次に、チェックバルブ３５の第四実施例について説明する。図６に示すように、チェックバルブ５５は、図３に示したチェックバルブ３５のスリーブ３６における大径部３６ａに円筒状部材６２を嵌装するとともに、該大径部３６ａの内壁を切り欠いて肉厚を他部よりも薄くした肉薄部３６ｔを形成したものである。このように構成することで、スリーブ３６がシート部材３７に当接してチェックバルブ５５が閉じているときには、肉薄部３６ｔがバネ室３６ｄ内の圧力により撓んで、大径部３６ａの外側方向へ膨らみ、該大径部３６ａの外周面とバルブ孔３２ｈの内周面との間の隙間が小さくなる（あるいは隙間がなくなる）ため、大径部３６ａとバルブ孔３２ｈとの間からの、メイン回路１３ｍ・２３ｍ内の作動油の漏れを減少することができる。一方、メイン回路１３ｍ・２３ｍ内の圧力が減少してチェックバルブ５５が開く際には、肉薄部３６ｔの撓み度合いが減少して大径部３６ａの外周面とバルブ孔３２ｈの内周面との間の隙間が大きくなるため、スリーブ３６が摺動する際の摺動抵抗は殆ど生じない。そして、スリーブ３６が上方摺動してキャップ３９の下面に当接する場合は、高剛性の部材で構成される円筒状部材６２が当接してストッパーの役割を果たすこととなるため、スリーブ３６の上端面３６ｅが摩耗することを防止することができる。
【００２２】
【発明の効果】
本発明は以上の如く構成したので、次のような効果を奏するのである。
請求項１においては、２ポンプ２モータ式ＨＳＴ（１）を、油圧ポンプ（１１）および油圧モータ（１２）により構成される第一ＨＳＴ（１０）と、油圧ポンプ（２１）および油圧モータ（２２）により構成される第二ＨＳＴ（２０）により構成し、該第一ＨＳＴ（１０）は車両の走行変速用に、第二ＨＳＴ（２０）は車両の操向旋回用に用い、該第一ＨＳＴ（１０）の油圧ポンプ（１１）と油圧モータ（１２）、及び第二ＨＳＴ（２０）の油圧ポンプ（２１）と油圧モータ（２２）とを、一枚の油路板（３２）上に配置して構成し、該油圧ポンプ（１１）と油圧モータ（１２）との間を連結する一対のメイン油路（１３ｍ）と、該油圧ポンプ（２１）と油圧モータ（２２）との間を連結する一対のメイン油路（２３ｍ）とを、同一の油路板（３２）に穿設配置し、各ＨＳＴ（１０・２０）のそれぞれのメイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）との間に設けられる油圧式無段変速機のチェックバルブ（３５）において、該チェックバルブ（３５）は、軸方向に貫通孔を有するスリーブ（３６）を、各メイン油路（１３ｍ・２３ｍ）の油路板端面近傍に形成されるバルブ孔（３２ｈ）に、メイン油路（１３ｍ・２３ｍ）方向へ摺動自在に嵌挿し、該バルブ孔（３２ｈ）のスリーブ（３６）より奥側に軸方向に貫通孔を有するシート部材（３７）を嵌装し、該スリーブ（３６）をシート部材（３７）側に付勢する付勢部材（３８）を設けて、該スリーブ（３６）とシート部材（３７）とが当接状態にあるときは、メイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）とが分断され、スリーブ（３６）とシート部材（３７）とが離間状態にあるときはメイン油路（１３ｍ・２３ｍ）とチャージ回路（３２ｃ）とが連通されるように構成し、該シート部材（３７）はバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）に着座して、該着座用段差（３２ｄ）への着座部外径をスリーブ（３６）の外径よりも小さく形成し、該スリーブ（３６）は、シート部材（３７）側の小径部（３６ｂ）と油路板端面側の大径部（３６ａ）とを有する段差形状に形成され、該シート部材（３７）の外径をスリーブ（３６）の大径部（３６ａ）の外径と同一又は小さく形成したので、全てのメイン回路に対してチェックバルブを組み込むことができ、油圧式無段変速機の上下方向にしかスペースがない場合でも、該チェックバルブのメンテナンスを容易に行うことが可能となる。さらに、シート部材が上方へ浮き上がることを防止することができる。
また、スリーブが当接するシート部材は、油路板と別体に形成されて、バルブ孔に摺動自在に嵌装されているので、耐磨耗性のある部材を用いることで耐久性を向上することができるとともに、仕組み性や分解性等、年メンテナンス性の向上を図ることができる。
【００２３】
請求項２に記載の如く、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）の内周に、上端を閉じたピストン部材（５２）を油路板（３２）端面側から摺動自在に挿入し、該スリーブ（３６）の大径部（３６ａ）とピストン部材（５２）との間に両者を離間方向に付勢する付勢部材（３８）を介装し、該シート部材（３７）におけるバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）への着座部外径を、前記ピストン部材（５２）の外径と同一又は小さく形成したので、
メイン回路内の作動油が低圧側に漏れだすためには、スリーブとピストンとの間、及びスリーブとバルブ孔ｈとの間の２箇所を通過する必要があるため、作動油の漏れ量を少なくすることができる。さらに、シート部材が上方へ浮き上がることを防止することができる。
また、スリーブ及びピストンを耐磨耗性がある部材で構成することで、両者間の隙間を長期間に渡って一定に保つことができるので、耐久性も向上することができる。
【００２４】
請求項３に記載の如く、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）と、バルブ孔（３２ｈ）との間に隙間を設け、該隙間に上端を閉じたピストン部材（５２）を油路板端面側から挿入し、該スリーブ（３６）とシート部材（３７）との間に両者を離間方向に付勢する付勢部材（３８）を介装し、シート部材（３７）におけるバルブ孔（３２ｈ）とメイン油路（１３ｍ・２３ｍ）との間の着座用段差（３２ｄ）への着座部外径をピストン部材（５２）の外径と同一又は小さく形成したので、
スリーブが摺接するピストンの材質を耐磨耗性材料とすることで、該スリーブとピストンとの間の隙間を長期間一定に保持することができ、耐久性を向上することができる。さらに、シート部材が上方へ浮き上がることを防止することができる。
また、スリーブとピストンとの間を所定寸法に構成していれば、スリーブを嵌挿するバルブ孔の径は多少ラフに形成しても、メイン回路内の作動油の漏れには影響がないため、バルブ孔の加工時間や加工費用を低減することができる。
【００２５】
請求項４に記載の如く、請求項１に記載の油圧式無段変速機のチェックバルブにおいて、前記スリーブ（３６）における大径部（３６ａ）内周に円筒状部材（６２）を嵌装するとともに、該内周に円筒状部材（６２）を嵌装した部分の大径部（３６ａ）の肉厚を、他部よりも薄く形成したので、チェックバルブが閉じているときには、大径部とバルブ孔との間の隙間が小さくなる（あるいは隙間がなくなる）ため、大径部とバルブ孔との間からの、メイン回路内の作動油の漏れを減少することができる。
一方、メイン回路内の圧力が減少してチェックバルブが開く際には、大径部とバルブ孔との間の隙間が大きくなるため、スリーブが摺動する際の摺動抵抗は殆ど生じない。
そして、スリーブが上方摺動してバルブ孔の上端面に当接する場合は、高剛性の部材で構成される円筒状部材が当接してストッパーの役割を果たすこととなるため、スリーブの上端面が摩耗することを防止することができる。
【図面の簡単な説明】
【図１】本発明のチェックバルブが装着される２ポンプ２モータ式ＨＳＴを示す側面断面図である。
【図２】同じく正面断面図である。
【図３】チェックバルブを示す側面断面図である。
【図４】チェックバルブの第二実施例を示す側面断面図である。
【図５】チェックバルブの第三実施例を示す側面断面図である。
【図６】チェックバルブの第四実施例を示す側面断面図である。
【図７】従来のチェックバルブを示す側面断面図である。
【符号の説明】
１２ポンプ２モータ式ＨＳＴ
１０第一ＨＳＴ
２０第二ＨＳＴ
１３ｍ・２３ｍメイン回路
３２油路板
３２ｃチャージ回路
３２ｈバルブ孔
３５チェックバルブ
３６スリーブ
３６ａ小径部
３６ｂ大径部
３６ｆ段差部
３７シート部材
３８コイルバネ[0001]
BACKGROUND OF THE INVENTION
The present invention provides a hydraulic continuously variable transmission that includes a hydraulic pump and a hydraulic motor and includes a pair of main oil passages, in which two hydraulic continuously variable transmissions are arranged on the same oil passage plate, between the main oil passage and the charge circuit. The present invention relates to a configuration of a check valve provided in the above.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a hydraulic continuously variable transmission (hereinafter referred to as an HST transmission) that includes a hydraulic pump and a hydraulic motor and has a pair of main oil passages, for example, as shown in FIG. Between the formed main circuits 32m and 32m and the charge circuit 32c, a check valve 93 configured by urging the valve member 93a with a coil spring 93b is provided. Each component of the check valve 93 is inserted in the direction orthogonal to the main circuits 32m and 32m from the left and right ends of the oil passage plate 32 to the inner charge circuit side. In addition, a valve seat 94 for sealing the space between the main circuit 32 m and the charge circuit 32 c is formed on the oil passage plate 32 by the pressure contact of the valve member 93 a.
[0003]
[Problems to be solved by the invention]
However, when two hydraulic continuously variable transmissions are arranged side by side on one oil passage plate, the check valve 93 can be inserted in a direction perpendicular to the main circuit 32m. Only the check valve 93 located on the left and right outer sides (the left and right end portions of the oil passage plate 32) of the continuously variable transmission, the check valve 93 located on the left and right inner sides (the left and right center portions of the oil passage plate 32) is connected to the main circuit 32m. Cannot be inserted in a direction perpendicular to the direction. In addition, when the check valve 93 is inserted from the direction orthogonal to the main circuit 32m, that is, from the left and right outer sides, when the space can be secured only in the direction (vertical direction) orthogonal to the main circuit 32m, maintenance of the check valve 93 is performed. Could not do.
[0004]
[Means for Solving the Problems]
The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.
In claim 1, the second pump 2-motor type HST (1), first as one HST (10) constituted by a hydraulic pump (11) and a hydraulic motor (12), a hydraulic pump (21) and the hydraulic motor (22 The second HST (20) is used for traveling shifting of the vehicle, the second HST (20) is used for steering turning of the vehicle,
The hydraulic pump (11) and hydraulic motor (12) of the first HST (10) and the hydraulic pump (21) and hydraulic motor (22) of the second HST (20) are connected to a single oil passage plate (32). And a pair of main oil passages (13m) connecting the hydraulic pump (11) and the hydraulic motor (12), the hydraulic pump (21) and the hydraulic motor (22) A pair of main oil passages (23m) connecting between the two are drilled and arranged in the same oil passage plate (32), and charged with each main oil passage (13m · 23m) of each HST (10 · 20). In the check valve (35) of the hydraulic continuously variable transmission provided between the circuit (32c) and the check valve (35), a sleeve (36) having a through hole in the axial direction is connected to each main oil passage ( 13m / 23m) Valve formed near end face of oil passage plate (32h) is slidably fitted in the direction of the main oil passage (13m, 23m), and a seat member (37) having a through hole in the axial direction on the back side from the sleeve (36) of the valve hole (32h). When an urging member (38) that is fitted and urges the sleeve (36) toward the sheet member (37) is provided, and the sleeve (36) and the sheet member (37) are in contact with each other When the main oil passage (13m / 23m) and the charge circuit (32c) are separated and the sleeve (36) and the seat member (37) are in a separated state, the main oil passage (13m / 23m) and the charge circuit ( 32c) and the seat member (37) is seated on a seating step (32d) between the valve hole (32h) and the main oil passage (13m, 23m). Three seating outer diameters on the step (32d) The sleeve (36) is formed in a stepped shape having a small diameter portion (36b) on the seat member (37) side and a large diameter portion (36a) on the end face side of the oil passage plate. The outer diameter of the formed sheet member (37) is the same as or smaller than the outer diameter of the large diameter portion (36a) of the sleeve (36).
[0005]
According to a second aspect of the present invention, in the check valve for the hydraulic continuously variable transmission according to the first aspect, a piston member (52) whose upper end is closed is provided on the inner periphery of the large diameter portion (36a) of the sleeve (36). An urging member (slidably inserted from the end face side of the oil passage plate (32) and urging both in the separating direction between the large diameter portion (36a) of the sleeve (36) and the piston member (52) ( 38), and the seat member outer diameter of the seat member (37) on the seat step (32d) between the valve hole (32h) and the main oil passage (13m, 23m) is set to the piston member (37). 52) which is the same or smaller than the outer diameter.
[0006]
According to claim 3, in the check valve of the hydraulic continuously variable transmission according to claim 1 , a gap is provided between the large diameter portion (36a) of the sleeve (36) and the valve hole (32h), A piston member (52) whose upper end is closed in the gap is inserted from the end face side of the oil passage plate, and an urging member (38) that urges both the sleeve (36) and the seat member (37) in the separating direction. ), And the seat portion outer diameter of the seat member (37) between the valve hole (32h) and the main oil passage (13m, 23m) to the seating step (32d) is outside the piston member (52). The diameter is the same as or smaller than the diameter.
[0007]
According to a fourth aspect of the present invention, in the check valve for the hydraulic continuously variable transmission according to the first aspect, the cylindrical member (62) is fitted on the inner periphery of the large diameter portion (36a) of the sleeve (36), The thickness of the large-diameter portion (36a) at the portion where the cylindrical member (62) is fitted to the inner periphery is formed thinner than the other portions.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. FIG. 1 is a side sectional view showing a two-pump two-motor HST equipped with the check valve of the present invention, FIG. 2 is a front sectional view, FIG. 3 is a side sectional view showing the check valve, and FIG. FIG. 5 is a side sectional view showing a third embodiment of the check valve, FIG. 6 is a side sectional view showing a fourth embodiment of the check valve, and FIG. 7 shows a conventional check valve. It is side surface sectional drawing.
[0009]
A schematic configuration of a hydraulic continuously variable transmission equipped with the check valve of the present invention will be described. 1 and FIG. 2 show a two-pump two-motor hydraulic continuously variable transmission (hereinafter referred to as HST) 1, and the two-pump two-motor HST 1 is composed of a hydraulic pump 11 and a hydraulic motor 12. The first HST 10 and the second HST 20 constituted by the hydraulic pump 21 and the hydraulic motor 22 are arranged on a single oil passage plate 32. For example, one of the first HST 10 and the second HST 20 is used for running the vehicle, and the other is used for turning.
[0010]
The hydraulic pump 11 constituting the first HST 10 includes a drive shaft 11a, a cylinder block 11b into which the drive shaft 11a is fitted and rotated together with the drive shaft 11a, a plunger 11e slidably fitted into the cylinder block 11b, and The movable swash plate 11c is in contact with the plunger 11e and is a variable displacement hydraulic pump. The movable swash plate 11c is configured to regulate the sliding amount of the plunger 11e and to adjust the discharge amount of the hydraulic oil of the hydraulic pump 11. The oil path plate 32 is provided with a pair of main circuits 13m and 13m, and hydraulic oil is supplied from the hydraulic pump 11 to the hydraulic motor 12 through the main circuit 13m.
[0011]
Similar to the hydraulic pump 11, the hydraulic motor 12 is inserted into the oil passage plate 32, and one end of the hydraulic motor 12 is rotatably supported by the housing 31, and the output shaft 12a is inserted and rotated together with the drive shaft 12a. The cylinder block 12b moves, the plunger 12e is slidably inserted in the cylinder block 12b, and the fixed swash plate 12c is in contact with the plunger 12e. The cylinder block 12b is configured to rotate together with the output shaft 12a, and a plunger 12e is slidably inserted into the cylinder block 12b. The plunger 12 e is in contact with a fixed swash plate 12 c fixed to the housing 31.
[0012]
With the above configuration, the driving force is input to the drive shaft 11a, and the hydraulic pump 11 is driven. The hydraulic oil discharged by the hydraulic pump 11 is supplied to the hydraulic motor 12 through the oil passage plate 31, and the hydraulic motor 12 is driven by the hydraulic oil, and the driving force is transmitted to the output shaft 12a. Further, the hydraulic pump 21 and the hydraulic motor 22 constituting the second HST 20 are configured in the same manner as the hydraulic pump 11 and the hydraulic motor 12.
[0013]
The oil passage plate 32 is formed with a charge circuit 32c. Between the charge circuit 32c and the main circuits 13m and 13m of the first HST 10 and the main circuits 23m and 23m of the second HST 20, respectively. A check valve 35 is interposed. And when the hydraulic fluid of each main circuit 13m * 23m runs short, it is comprised so that hydraulic fluid may be replenished to the main circuit 13m * 23m via this check valve 35 from the charge circuit 32c32c. The check valve 35 is inserted in the valve hole 32h formed at the upper end of each main circuit 13m / 23m in the oil passage plate 32 from the upper end surface of the oil passage plate 32 in the main circuit 13m / 23m direction (vertical direction). Has been.
[0014]
Next, the check valve 35 provided between the main circuits 13m and 23m and the charge circuit 32c will be described. As shown in FIG. 3, each check valve 35 has a sleeve 36 in the main circuit 13m / 23m direction (vertical direction) with respect to a valve hole 32h formed near the end face of the oil passage plate 32 of each main circuit 13m / 23m. And a seat member 37 is fitted inside (lower) the sleeve 36 of the valve hole 32h, and is interposed between the sleeve 36 and a cap 39 that closes the valve hole 32h from above. A coil spring 38 for urging the sleeve 36 toward the sheet member 37 is provided. The sleeve 36 is formed in a stepped shape having a small diameter portion 36 b on the sheet member 37 side and a large diameter portion 36 a on the cap 39 side at the end of the oil passage plate 32, and the sheet member 37 is formed of a small diameter portion 36 b of the sleeve 36. It is comprised by the cylindrical member in which the sheet | seat part 37b with which the front-end | tip contact | abutted was formed.
[0015]
When the sleeve 36 is in contact with the seat member 37, the main oil passages 13m and 23m are separated from the charge circuit, and when the sleeve 36 and the seat member 37 are in a separated state, the main oil passages 13m and 23m are charged. The circuit 32c is configured to communicate with the circuit 32c. The spring chamber 36d in which the coil spring 38 is accommodated communicates with the main circuits 13m and 23m through a communication hole 36c formed in the small diameter portion 36b of the sleeve 36 and a communication hole 37a of the seat portion 37b. -The pressure within 23 m is applied to the closing direction pressure receiving surface 36 e of the sleeve 36. Further, the pressure in the charge circuit 32 c is applied in the opening direction of the sleeve 36 to the step portion 36 f formed between the large diameter portion 36 a and the small diameter portion 36 b of the sleeve 36.
[0016]
The force applied in the closing direction of the sleeve 36 (the direction in which the sleeve 36 and the sheet member 37 abut), which is the pressure in the main circuits 13m and 23m applied to the closing direction pressure receiving surface 36e, and the biasing force of the coil spring 38, When the pressure in the charging circuit 32c is higher than the stepped portion 36f in the opening direction of the sleeve 36 (the direction in which the sleeve 36 and the sheet member 37 are separated), the sleeve 36 abuts against the sheet member 37 and closes. The circuit 32c and the main circuits 13m and 23m are divided. On the other hand, when the force applied to the stepped portion 36f is larger than the force applied to the pressure applied to the closing direction pressure receiving surface 36e and the urging force of the coil spring 38, the sleeve 36 and the seat member 37 are opened apart from each other. 32c communicates with the main circuits 13m and 23m. That is, when the hydraulic oil in the main circuits 13m and 23m is insufficient and the force applied in the closing direction of the sleeve 36 decreases, the hydraulic oil is supplied from the charge circuit 32c32c to the main circuits 13m and 23m via the check valve 35. It is comprised so that.
[0017]
A seating step 32d is formed between the valve hole 32h and the main circuits 13m and 23m, and a seat member 37 is seated on the seating step 32d. And the diameter D2 of the seating part of the seat member 37 is formed smaller than the outer diameter D3 of the seat member 37, and the outer diameter D3 of the seat member 37 is equal to the outer diameter D1 of the large diameter part 36a of the sleeve 36. They are the same or smaller. By forming in this way, the pressure receiving area diameter D2 of the upward pressure applied to the sheet member 37 is smaller than the pressure receiving area diameter D1 of the downward force, and the sheet member 37 is prevented from floating upward. be able to.
[0018]
The check valve 35 configured as described above is configured by inserting the sleeve 36 and the seat member 37 from above and below in the same direction as the main circuits 13m and 23m. Can be incorporated in all the main circuits 13m and 23m even in the case where they are arranged side by side on one oil passage plate 32, and in the vertical direction of the first and second HSTs 10 and 20. Even when there is only a space, the check valve 35 can be easily maintained. Further, since the sheet member 37 with which the sleeve 36 abuts is formed separately from the oil passage plate 32 and is slidably fitted into the valve hole 32h, a wear-resistant member is used. In addition to improving durability, it is possible to improve maintainability such as mechanism and decomposability.
[0019]
Next, a second embodiment of the check valve 35 will be described. As shown in FIG. 4, the check valve 45 has a piston 42 whose upper end is closed in the spring chamber 36d of the check valve 35 shown in FIG. A coil spring 38 is interposed therebetween. In the case of the aforementioned check valve 35, the sleeve 36 is slidably inserted into the valve hole 32h, so that hydraulic fluid in the main circuits 13m and 23m leaks from between the sleeve 36 and the valve hole 32h. As a result, the efficiency of the first and second HSTs 10 and 20 is reduced. In the check valve 45 of this example, in order for the hydraulic oil in the main circuits 13m and 23m to leak to the low pressure side, the sleeve 36 and Since it is necessary to pass through two places between the piston 42 and between the sleeve 36 and the valve hole 32h, the amount of hydraulic oil leakage can be reduced. In addition, since the sleeve 36 and the piston 42 are made of wear-resistant members, the gap between the two can be kept constant over a long period of time, so that the durability can be improved. In addition, the diameter D2 of the seating portion of the seat member 37 is formed to be the same diameter or smaller than the outer diameter D4 of the piston 42, and the seat member 37 is prevented from floating upward.
[0020]
Next, a third embodiment of the check valve 35 will be described. As shown in FIG. 5, the check valve 55 is fitted between the valve hole 32h shown in FIG. 3 and the large-diameter portion 36a of the sleeve 36 so that the piston 52 with its upper end closed can be slid up and down from above. A coil spring 38 is interposed between the piston 52 and the sleeve 36. In general, the oil passage plate 32 in which the valve hole 32d into which the sleeve 36 is inserted is formed is made of cast iron, and thus is easily worn and cannot be said to have a very high durability. Therefore, in this example, the material of the piston 52 that is in sliding contact with the sleeve 36 is made of an abrasion-resistant material, so that the gap between the sleeve 36 and the piston 52 can be kept constant for a long period of time. Can be improved. In addition, if the sleeve 36 and the piston 52 are configured to have a predetermined size, the operating oil in the main circuits 13m and 23m can be obtained even if the valve hole 32d into which the sleeve 36 is inserted is somewhat rough. Since the leakage is not affected, the processing time and processing cost of the valve hole 32d can be reduced. In addition, the diameter D2 of the seating portion of the seat member 37 is formed to be equal to or smaller than the outer diameter D5 of the piston 52, and prevents the seat member 37 from floating upward.
[0021]
Next, a fourth embodiment of the check valve 35 will be described. As shown in FIG. 6, the check valve 55 has a cylindrical member 62 fitted into the large diameter portion 36a of the sleeve 36 of the check valve 35 shown in FIG. 3, and the inner wall of the large diameter portion 36a is cut away. A thin portion 36t having a thinner thickness than the other portions is formed. With this configuration, when the sleeve 36 is in contact with the seat member 37 and the check valve 55 is closed, the thin portion 36t is bent by the pressure in the spring chamber 36d and bulges outward from the large diameter portion 36a. Since the gap between the outer peripheral surface of the large-diameter portion 36a and the inner peripheral surface of the valve hole 32h becomes small (or the gap disappears), the main circuit 13m from between the large-diameter portion 36a and the valve hole 32h.・ Leakage of hydraulic oil within 23m can be reduced. On the other hand, when the pressure in the main circuits 13m and 23m decreases and the check valve 55 opens, the degree of bending of the thin portion 36t decreases, and the outer peripheral surface of the large-diameter portion 36a and the inner peripheral surface of the valve hole 32h. Since the gap between them becomes large, there is almost no sliding resistance when the sleeve 36 slides. When the sleeve 36 slides upward and comes into contact with the lower surface of the cap 39, the cylindrical member 62 made of a high-rigidity member comes into contact and serves as a stopper. It is possible to prevent the end face 36e from being worn.
[0022]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
In claim 1, a two-pump two-motor HST (1) is divided into a first HST (10) composed of a hydraulic pump (11) and a hydraulic motor (12), a hydraulic pump (21) and a hydraulic motor (22). ), The first HST (10) is used for shifting the vehicle, the second HST (20) is used for steering turning of the vehicle, and the first HST (20) is used. The hydraulic pump (11) and the hydraulic motor (12) of (10) and the hydraulic pump (21) and the hydraulic motor (22) of the second HST (20) are arranged on a single oil passage plate (32). A pair of main oil passages (13m) for connecting the hydraulic pump (11) and the hydraulic motor (12), and for connecting the hydraulic pump (21) and the hydraulic motor (22). A pair of main oil passages (23m), and the same oil passage plate (32), a check valve (35 of a hydraulic continuously variable transmission provided between the main oil passages (13m, 23m) and the charge circuit (32c) of each HST (10, 20). ), The check valve (35) includes a sleeve (36) having a through hole in the axial direction in a valve hole (32h) formed in the vicinity of the end face of the oil passage plate of each main oil passage (13m, 23m). A seat member (37) having a through hole in the axial direction on the back side from the sleeve (36) of the valve hole (32h) is fitted and slidably fitted in the main oil passage (13m / 23m) direction, A biasing member (38) that biases the sleeve (36) toward the seat member (37) is provided, and when the sleeve (36) and the seat member (37) are in contact with each other, the main oil passage ( 13m / 23m) and charge circuit (32c) And the main oil passage (13m / 23m) and the charge circuit (32c) are communicated with each other when the sleeve (36) and the seat member (37) are separated from each other. (37) is seated on the seating step (32d) between the valve hole (32h) and the main oil passage (13m, 23m), and the outer diameter of the seating portion on the seating step (32d) is set to the sleeve (36). The sleeve (36) is formed in a stepped shape having a small diameter portion (36b) on the seat member (37) side and a large diameter portion (36a) on the oil path plate end surface side. Since the outer diameter of the seat member (37) is the same as or smaller than the outer diameter of the large-diameter portion (36a) of the sleeve (36), a check valve can be incorporated into all main circuits. Space only in the vertical direction of continuously variable transmission Even if no, it is possible to easily perform maintenance of the check valve. Furthermore, the sheet member can be prevented from floating upward.
In addition, the seat member with which the sleeve abuts is formed separately from the oil passage plate and is slidably fitted into the valve hole, so durability is improved by using a wear-resistant member. In addition, it is possible to improve annual maintenance such as mechanism and decomposability.
[0023]
As described in claim 2, in the check valve of the hydraulic stepless transmission according to claim 1, the inner periphery of the large diameter portion (36a) in the sleeve (36), the piston member (52 closing the upper end ) Is slidably inserted from the end face side of the oil passage plate (32), and is urged between the large diameter portion (36a) of the sleeve (36) and the piston member (52) in the separating direction. The piston member is provided with an outer diameter of a seating portion on a seating step (32d) between a valve hole (32h) and a main oil passage (13m, 23m) in the seat member (37). Since it is formed to be the same or smaller than the outer diameter of the member (52),
In order for the hydraulic oil in the main circuit to leak to the low pressure side, it is necessary to pass through two places between the sleeve and the piston and between the sleeve and the valve hole h, so the amount of hydraulic oil leakage is reduced. can do. Furthermore, the sheet member can be prevented from floating upward.
Further, since the sleeve and the piston are made of a wear-resistant member, the gap between the two can be kept constant over a long period of time, so that the durability can be improved.
[0024]
According to a third aspect of the present invention , in the check valve for the hydraulic continuously variable transmission according to the first aspect, a gap is formed between the large diameter portion (36a) of the sleeve (36) and the valve hole (32h). An urging member that is provided and inserts a piston member (52) whose upper end is closed in the gap from the end face side of the oil passage plate, and urges both the sleeve (36) and the sheet member (37) in the separating direction. (38), and the seat member outer diameter of the seating step (32d) between the valve hole (32h) and the main oil passage (13m, 23m) in the seat member (37) is defined as the piston member (52). Because it was formed to be the same or smaller than the outer diameter of
By making the material of the piston with which the sleeve slides into wear-resistant material, the gap between the sleeve and the piston can be kept constant for a long period of time, and the durability can be improved. Furthermore, the sheet member can be prevented from floating upward.
In addition, if the sleeve and the piston are configured to have a predetermined size, even if the diameter of the valve hole into which the sleeve is inserted is formed somewhat rough, it does not affect the leakage of hydraulic oil in the main circuit. The processing time and processing cost of the valve hole can be reduced.
[0025]
According to a fourth aspect of the present invention , in the check valve for the hydraulic continuously variable transmission according to the first aspect, the cylindrical member (62) is fitted to the inner periphery of the large diameter portion (36a) of the sleeve (36). In addition, since the thickness of the large-diameter portion (36a) where the cylindrical member (62) is fitted to the inner periphery is formed thinner than the other portions, when the check valve is closed, Since the gap between the valve hole is small (or the gap is eliminated), the leakage of hydraulic oil in the main circuit from between the large diameter portion and the valve hole can be reduced.
On the other hand, when the pressure in the main circuit decreases and the check valve opens, the gap between the large diameter portion and the valve hole increases, so that almost no sliding resistance occurs when the sleeve slides.
When the sleeve slides upward and comes into contact with the upper end surface of the valve hole, a cylindrical member made of a highly rigid member comes into contact with the sleeve and acts as a stopper. Abrasion can be prevented.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a two-pump two-motor HST equipped with a check valve of the present invention.
FIG. 2 is a front sectional view of the same.
FIG. 3 is a side sectional view showing a check valve.
FIG. 4 is a side sectional view showing a second embodiment of the check valve.
FIG. 5 is a side sectional view showing a third embodiment of the check valve.
FIG. 6 is a side sectional view showing a fourth embodiment of the check valve.
FIG. 7 is a side cross-sectional view showing a conventional check valve.
[Explanation of symbols]
1 2 pump 2 motor type HST
10 1st HST
20 Second HST
13m / 23m Main circuit 32 Oil passage plate 32c Charge circuit 32h Valve hole 35 Check valve 36 Sleeve 36a Small diameter part 36b Large diameter part 36f Step part 37 Sheet member 38 Coil spring

Claims

A two-pump, two-motor HST (1) is a first HST (10) configured by a hydraulic pump (11) and a hydraulic motor (12), and a first HST (10) configured by a hydraulic pump (21) and a hydraulic motor (22). The first HST (10) is used for shifting the vehicle, the second HST (20) is used for steering and turning of the vehicle, and the first HST (10) is a hydraulic pump. (11), the hydraulic motor (12), and the hydraulic pump (21) and the hydraulic motor (22) of the second HST (20) are arranged on a single oil passage plate (32), A pair of main oil passages (13m) connecting between the hydraulic pump (11) and the hydraulic motor (12), and a pair of main oil passages connecting between the hydraulic pump (21) and the hydraulic motor (22). (23m) is drilled and arranged in the same oil passage plate (32). Each of the main oil passage of the HST (10 · 20) (13m · 23m) and the charge circuit in the check valve (35) of the hydrostatic continuously variable transmission provided between (32c), said check valve (35) In the main oil passage (13m / 23m) direction, the sleeve (36) having a through hole in the axial direction is inserted into a valve hole (32h) formed in the vicinity of the oil passage plate end face of each main oil passage (13m · 23m). A seat member (37) having a through hole in the axial direction on the back side from the sleeve (36) of the valve hole (32h) is fitted, and the sleeve (36) is inserted into the seat member (37). ) Side is provided, and when the sleeve (36) and the seat member (37) are in contact with each other, the main oil passage (13m, 23m) and the charge circuit (32c) ) And split, The main oil passage (13m, 23m) and the charge circuit (32c) are communicated with each other when the hub (36) and the seat member (37) are in a separated state, and the seat member (37) is a valve Seat on the seating step (32d) between the hole (32h) and the main oil passage (13m, 23m), and set the seating portion outer diameter to the seating step (32d) from the outer diameter of the sleeve (36). The sleeve (36) is formed in a stepped shape having a small diameter portion (36b) on the seat member (37) side and a large diameter portion (36a) on the end face side of the oil passage plate, 37) A check valve for a hydraulic continuously variable transmission, wherein the outer diameter of 37) is formed to be the same as or smaller than the outer diameter of the large diameter portion (36a) of the sleeve (36).

2. A check valve for a hydraulic continuously variable transmission according to claim 1, wherein a piston member (52) whose upper end is closed is provided on the inner periphery of the large diameter portion (36a) of the sleeve (36). A biasing member (38) is inserted between the large-diameter portion (36a) of the sleeve (36) and the piston member (52) so as to be slidable from the end face side and biased in the separating direction. The seat portion outer diameter of the seat member (37) between the valve hole (32h) and the main oil passage (13m, 23m) to the seating step (32d) is defined as the outer diameter of the piston member (52). A check valve for a hydraulic continuously variable transmission, which is the same or smaller.

The check valve for the hydraulic continuously variable transmission according to claim 1, wherein a gap is provided between the large diameter portion (36a) of the sleeve (36) and the valve hole (32h), and the upper end is closed in the gap. The piston member (52) is inserted from the end face side of the oil passage plate, and a biasing member (38) for biasing both in the separating direction is interposed between the sleeve (36) and the seat member (37), The outer diameter of the seating portion on the seating step (32d) between the valve hole (32h) and the main oil passage (13m, 23m) in the seat member (37) is the same as or smaller than the outer diameter of the piston member (52). A check valve for a hydraulic continuously variable transmission.

The check valve for a hydraulic continuously variable transmission according to claim 1, wherein a cylindrical member (62) is fitted to the inner periphery of the large diameter portion (36a) of the sleeve (36), and the inner periphery is cylindrical. check valves of the hydrostatic continuously variable transmission, characterized in that the wall thickness of the large diameter portion of the portion fitted member (62) (36a), formed thinner than the other portion.