JP2003090268A - Vaporizer for internal combustion engine - Google Patents
Vaporizer for internal combustion engineInfo
- Publication number
- JP2003090268A JP2003090268A JP2001283497A JP2001283497A JP2003090268A JP 2003090268 A JP2003090268 A JP 2003090268A JP 2001283497 A JP2001283497 A JP 2001283497A JP 2001283497 A JP2001283497 A JP 2001283497A JP 2003090268 A JP2003090268 A JP 2003090268A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- valve
- chamber
- passage
- primary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/30—Use of alternative fuels, e.g. biofuels
Abstract
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は内燃機関に向けて液化石
油ガス（ＬＰＧ）、圧縮天然ガス（ＣＮＧ）等のガス燃
料を供給する燃料供給装置に関し、そのうちガス燃料源
内のガス燃料を１次減圧室にて所定の１次圧に減圧する
とともに２次減圧室にて略大気圧状態の２次圧に減圧す
るベーパーライザに関する。
【０００２】
【従来の技術】従来のベーパーライザＶについて図４に
より説明する。２０は、筐体Ｂを１次調圧室２１と１次
減圧室２２とに区分する１次ダイヤフラムであり、１次
ダイヤフラム２０は１次調圧室２１内に縮設して配置さ
れる１次スプリング２３のバネ力によって１次減圧室２
２側へ押圧される。２４は１次減圧室２２内において回
転自在に支承される第１次支持杆２５の一端に配置され
る１次弁であり、この１次弁２４は１次減圧室２２に開
口する燃料流入路２６を開閉制御する。又前記第１支持
杆２５の他端は前記１次ダイヤフラム２０に係止され
る。２７は、１次減圧室２２から外部に向かって開口す
る１次燃料吐出路であり、該１次燃料吐出路は、スロー
ロック弁２８によって開閉される。２９は、前記スロー
ロック弁と連結杆２９Ａを介して連結され、スローロッ
ク弁２８に対して開閉操作力を付与するスローロックダ
イヤフラムであり、スローロックダイヤフラム２９によ
って画成されるスローロック受圧室３０内にはスローロ
ックダイヤフラム２９を図４において右方へ押圧するス
ローロックスプリング３１が縮設される。いいかえると
スローロックスプリング３１はスローロック弁２８が１
次燃料吐出路２７を閉塞する側へ付勢するといえる。そ
してスローロック受圧室３０には負圧導入路３２を介し
て機関の運転によって生起する負圧が導入される。本例
では負圧導入路３２の上流側は後述するミキシングボデ
ーの吸気路に連絡される。３３は１次燃料吐出路２７を
流れるガス燃料量を調圧、制御する１次調整スクリュー
であり、先端にテーパー針弁部が形成される。筐体Ｂ
は、更に２次ダイヤフラム３４によって２次調圧室３５
と２次減圧室３６とに区分され、２次減圧室３６には１
次減圧室２２に連なる２次燃料流入路３７と外部に向か
う２次燃料吐出路３８とが開口する。３９は２次減圧室
３６内に回転自在に支承配置される第２支持杆であり、
この第２支持杆３９の一端に２次燃料流入路３７を開閉
する２次弁４０が配置されるとともにその他端は２次ダ
イヤフラム３４に係止される。又、前記第２支持杆は２
次スプリング４１のバネ力によって反時計方向へ付勢さ
れるもので、これによって２次弁４０は２次燃料流入路
３７を閉塞する側へ押圧される。そして、ベーパーライ
ザＶの燃料流入路２６には、ガス燃料としての液化石油
ガス（ＬＰＧ）が供給される。液化石油ガス（以下ＬＰ
Ｇという）を使用する際、ガス燃料源Ｔ１内の約５ｋｇ
/ｃｍ２ の圧力を有するＬＰＧは、直接的に燃料導入
路２６に供給される。一方ＬＰＧに代えて圧縮天然ガス
（以下ＣＮＧという）を使用することができるもので、
このときガス燃料源Ｔ２内の約２００ｋｇ/ｃｍ２ の
圧力を有するＣＮＧは、１次レギュレターＲによって約
６ｋｇ/ｃｍ２ の圧力を減圧され、この減圧されたＣ
ＮＧが燃料流入路２６へ供給される。Ｍは、前記ベーパ
ーライザからのガス燃料の供給を受け、機関に向けて空
気とガス燃料との混合気を図示せぬ吸気管を介して供給
するミキシングボデーで以下よりなる。ミキシングボデ
ーＭは内部を吸気路４０が貫通して穿設され、その上流
にミキサーベンチュリー部４１が形成される。前記吸気
路はミキシングボデーＭに回転自在に支承された絞り弁
軸４２に取着された絞り弁４３にて開閉制御され、一方
ミキサーベンチュリー部４１には複数のメーンポート４
４が開口して形成されるもので、このメーンポート４４
は、ミキサーベンチュリー部４１を囲繞して形成された
環状溝部４５を介して２次圧燃料導入路４６に連絡され
る。又、４７は絞り弁４３より下流側の吸気路４０Ａに
開口するアイドルポートであり、これには１次圧燃料導
入路４８が連絡される。そして、前記２次圧燃料導入路
は、ベーパーライザＶの２次燃料吐出路３８に接続さ
れ、１次圧燃料導入路４８は１次燃料吐出路２７に接続
される。
【０００３】ベーパーライザＶにおいて、１次弁２４
は、ガス燃料自身が有する燃料圧力（ＬＰＧにあっては
約５ｋｇ／ｃｍ２の燃料圧力、ＣＮＧにあっては１次レ
ギュレターＲによって減圧された約６ｋｇ/ｃｍ２の燃
料圧力）によって燃料流入路２６を開放し、前記ガス燃
料が１次減圧室２２内へ供給される。そして１次減圧室
２２内の圧力が所定の圧力（例えば０.３ｋｇ／ｃ
ｍ２）を超えて上昇すると、１次ダイヤフラム２０が１
次スプリング２３のバネ力に抗して１次調圧室２１側へ
移動し、これによって第１支持杆２５が反時計方向へ回
転して１次弁２４が燃料流入路２６を閉塞し、もって１
次減圧室２２内のガス燃料圧力を０．３ｋｇ／ｃｍ２に
調圧できる。一方、１次減圧室２２内のガス燃料圧力が
０．３ｋｇ／ｃｍ２以下の圧力に低下すると、１次スプ
リング２３は、１次ダイヤフラム２０を１次減圧室２２
側へ押圧して移動させ、これによって第１支持杆２５は
時計方向に回転して１次弁２４は燃料流入路２６を開放
する。従って燃料流入路２６より高圧力状態のガス燃料
が１次減圧室２２内へ供給され、これによって１次減圧
室２２内のガス燃料圧力を再び所定の０．３ｋｇ／ｃｍ
２に復帰させることができる。以後、上記１次弁の動作
がくり返し行なわれることによって、１次減圧室２２内
には、１次圧としての所定の０．３ｋｇ／ｃｍ２の圧力
を有するガス燃料が維持されるものである。そして、機
関が始動されると、ミキシングボデーＭの絞り弁４３よ
り下流側の吸気路４０Ａ内に負圧が生ずるもので、この
負圧は負圧導入路３２を介してスローロック受圧室３０
内へ導入される。これによるとスローロックダイヤフラ
ム２９は、スローロックスプリング３１のバネ力に抗し
て図において左方へ移動し、（いいかえるとスローロッ
ク受圧室３０側へ移動する）このスローロックダイヤフ
ラム２９の左方移動が連結杆２９Ａによってスローロッ
ク弁２８に伝達され、スローロック弁２８は１次燃料吐
出路２７を開放する。以上によると、１次圧を有する１
次減圧室２２内のガス燃料は、１次調整スクリュー３３
によってその量が制御され、このガス燃料が１次燃料吐
出路２７、１次圧燃料導入路４８、を介してアイドルポ
ート１７へ供給され、これによって機関の始動及び低開
度運転が行なわれる。
【０００４】一方、２次減圧室３６にあっては、ガス燃
料は大気圧まで減圧される。前述の如く、１次減圧室２
２内のガス燃料圧力は０．３ｋｇ／ｃｍ２に調圧される
もので、この０．３ｋｇ／ｃｍ２の圧力を有するガス燃
料は２次燃料流入路３７を介して２次弁４０に作用し、
２次弁４０は２次燃料流入路３７を開放し、２次減圧室
３６内にガス燃料が供給される。ここで、２次減圧室３
６内のガス燃料圧力が大気圧以上に上昇すると、２次ダ
イヤフラム３４は２次調圧室３５側へ変位し、これによ
ると第２支持杆３９は２次スプリング４１のバネ力によ
って反時計方向へ回転して２次弁４０は２次燃料流入路
３７を閉塞し、これによって２次減圧室３６内のガス燃
料圧力を大気圧に復帰させる。又、２次減圧室３６内の
ガス燃料圧力が大気圧以下に低下すると、２次ダイヤフ
ラム３４は２次スプリング４１のバネ力に抗して２次減
圧室３６側へ変位し、これによると第２支持杆３９は時
計方向へ回転して２次弁４４は２次燃料流入路３７を開
放し、これによって２次減圧室３６内のガス燃料圧力を
大気圧に復帰させる。以後、上記２次弁４０が前記動作
をくり返し行なうことによって２次減圧室３６内のガス
燃料圧力を２次圧としての大気圧に維持できる。そし
て、絞り弁４３が吸気路４０を中開度及び高開度に開放
することによると、ミキサーベンチュリー部４１には絞
り弁開度に応じた高い負圧が生起するもので、この負圧
はメーンポート４４、環状溝部４５、２次圧燃料導入路
４６、２次燃料吐出路３８を介して２次減圧室３６に作
用し、２次減圧室３６内に維持される大気圧状態にある
ガス燃料がメーンポート４４を介してミキサーベンチュ
リー部４１に吸出され、これによって絞り弁４３の中及
び高開度運転が行なわれる。
【０００５】
【発明が解決しようとする課題】かかる従来のベーパー
ライザを用いることによると、絞り弁を低開度から高開
度に向けて連続的に開閉動作を行なうスナップ動作時に
おいて機関の運転性が阻害される恐れがある。これは以
下の理由による。絞り弁４３の低開度時において、絞り
弁４３より下流側の吸気路４０Ａ内には大なる負圧が生
起され、この大なる負圧が負圧導入路３２を介してスロ
ーロック受圧室３０内に導入される。以上によると、ス
ローロックダイヤフラム２９はスローロックスプリング
３１のバネ力に抗してスローロック受圧室３０側へ変位
し、これによると、スローロック弁２８が１次燃料吐出
路２７を開放し、１次減圧室２２内の１次圧を有するガ
ス燃料がアイドルポート４７を介してミキシングボデー
Ｍの吸気路４０に供給され、これによって絞り弁４３の
低開度運転が行なわれる。そして、かかる絞り弁４３の
低開度状態から絞り弁４３が急激に開放されると、吸気
路４０内の負圧は一時的に低下（大気圧に近づくこと）
するもので、この低下した負圧が負圧導入路３２を介し
てスローロック受圧室３０内へ導入されると、スローロ
ックダイヤフラム２９は、スローロックスプリング３１
のバネ力によって２次減圧室３６側（図において右方）
へ移動する。以上によると、スローロック弁２８はスロ
ーロックダイヤフラム２９と同期して図において右方へ
移動し、１次燃料吐出路２７を閉塞し、アイドルポート
４７から吸気路４０内に向かう１次圧を有するガス燃料
の供給を一時的に停止することになる。そして、前記絞
り弁の開及び閉動作が連続的に行なわれるスナップ動作
が行なわれると、吸気路４０内を流れるガス燃料の混合
気濃度は希薄化し、機関の回転数が所定の回転数より低
下し、機関が停止する恐れがある。
【０００６】本発明は前記不具合に鑑み成されたもので
絞り弁が低開度から高開度に向けて連続的に開閉される
スナップ動作時において、ガス燃料の供給が遮断され
て、ガス燃料の混合気濃度が希薄化されることがなく、
安定した機関の運転を得ることのできる内燃機関用のベ
ーパーライザを提供することを目的とする。
【０００７】
【課題を達成する為の手段】本発明になる内燃機関用の
ベーパーライザは前記課題を達成する為に、ガス燃料源
内のガス燃料を、１次減圧室にて所定の１次圧に減圧す
るとともに２次減圧室にて略大気圧状態の２次圧に調圧
するベーパーライザにおいて；１次減圧室から外部に向
かって開口する１次燃料吐出路に、該通路を吸気路内の
負圧に応じて開閉するスローロック弁が配置されるとと
もにスローロック弁に開閉操作力を付与するスローロッ
クダイヤフラムによって区分されるスローロック受圧室
と吸気路とを連絡する負圧導入路に圧力制御弁が配置さ
れ、前記圧力制御弁を、吸気路内に生起する負圧が一定
負圧値以上において、弁孔によって区分される上流室と
下流室とを連通し、それ以下の負圧で弁孔を閉塞する逆
止弁と、弁孔を迂回して上流室と下流室を連絡するバイ
パス通路に配置され、一定開口をもって常時連通する制
御オリフィスと、によって形成したことを特徴とする。
【０００８】
【作用】絞り弁の低開度において、圧力制御弁の逆止弁
には吸気路内に生起する大なる負圧が作用し、逆止弁は
弁孔を開放保持する。従って、吸気路内の大なる負圧
は、弁孔、負圧導入路を介してスローロック受圧室内へ
導入され、これによってスローロック弁は１次燃料吐出
路を開放保持し、１次減圧室内の１次圧を有するガス燃
料が１次燃料吐出路、アイドルポートを介して吸気路内
へ供給される。一方、絞り弁が前記低開度状態から急激
に高開度に開放されると、吸気路内の負圧は大きく低下
するもので、この低下した負圧が逆止弁に作用すると、
逆止弁は即座に弁孔を閉塞する。以上によると、スロー
ロック受圧室内には大なる負圧が保持され、スローロッ
ク弁は依然として１次燃料吐出路を開放保持する。従っ
て、絞り弁が連続的に開及び閉動作されるスナップ動作
が行なわれた際において、１次燃料吐出路からガス燃料
の供給が一時的に停止されることがなく機関の運転を安
定して行なうことができる。一方、スローロック受圧室
内の大なる負圧の一部はバイパス通路、制御オリフィス
を介して下流室から上流室に向けて微少にリークされる
ので、スローロック受圧室内の大なる負圧は徐々に弱め
られるので、混合気濃度の適性化を達成できる。
【０００９】
【実施例】以下、本発明になる内燃機関用のベーパーラ
イザの一実施例を図により説明する。図１は本発明にな
る内燃機関用のベーパーライザの一実施例を示す縦断面
図。図２は図１において用いられる圧力制御弁の縦断面
図。図３は図１のＡ−Ａ線における縦断面図、である。
本発明になるベーパーライザは、従来のベーパーライザ
に対し、圧力制御弁Ｐが付加されたものである。尚、従
来と同一なる構成部分は同一符号を使用して説明を省略
する。圧力制御弁Ｐは以下よりなる。（特に図２，図３
によって説明する）１は一側端面１Ａと他側端面１Ｂと
を備える仕切壁体であり、一側端面１Ａから他側端面１
Ｂに向けて弁孔２とバイパス通路３とが貫通して穿設さ
れる。前記弁孔２とパイパス通路３とは仕切壁体１内に
並列に形成されるもので、弁孔２とバイパス通路３とは
直接的に連絡されない。４は、仕切壁体１の一側端面１
Ａ上に配置される。凹部４Ａを有する有底カップ状の上
流カバーであり、凹部４Ａには上流通路４Ｂが開口す
る。５は仕切壁体１の一側端面１Ａ上に配置される薄板
状をなす制御板であり、この制御板５には仕切壁体１の
弁孔１を開閉しうる逆止弁６と、バイパス通路３に臨ん
で制御オリフィス７とが形成される。具体的にこの制御
板５は、例えば０．５ミリメートル程度の板厚を有する
薄板ステンレス材料で形成されるもので、逆止弁６はＵ
字状の舌片部により形成され、制御オリフィス７は微少
孔で形成される。尚、この逆止弁６の開弁特性及び制御
オリフィス７が微少孔の径はそれぞれの機関への適合テ
ストによって決定される。８は、仕切壁体１の他側端面
１Ｂ上に配置される。凹部８Ａを有する有底カップ状の
下流カバーであり、凹部８Ａには下流通路８Ｂが開口す
る。そして、前記仕切壁体１の一側端面１Ａ上に制御板
５と上流カバー４が配置され、他側端面１Ｂ上に下流カ
バー８が配置され、この状態において上流カバー４、制
御板５、仕切壁体１、下流カバー８がネジ９によって一
体的に組みつけられる。以上によると、仕切壁体１の一
側端面１Ａと上流カバー４の凹部４Ａとによって上流室
ＰＡが形成され、他側端面１Ｂと下流カバー８の凹部８
Ａとによって下流室ＰＢが形成され、この上流室ＰＡに
上流通路４Ｂが開口し、下流室ＰＢに下流通路８Ｂが開
口する。又、制御板５はその外周が仕切壁体１の一側端
面１Ａと上流カバー４とによって固定的に支持されるも
ので、このとき逆止弁６は弁孔２に臨んで配置され、制
御オリフィス７はバイパス通路３に臨んで配置される。
尚、制御板５は仕切壁体１の一側面１Ａと気密的に当接
配置されるもので、この気密保持の為のシールリング、
接着等の記載は省略された。従って、弁孔２と上流室Ｐ
Ａとは逆止弁６をもってのみ開閉制御され、バイパス通
路３は制御オリフィス７をもってのみ上流室ＰＡと連結
される。制御板５、逆止弁６の周囲と弁孔２が連通され
ることがなく、制御オリフィス７の周囲とバイパス通路
３が連通されることもない。尚、４Ｃは逆止弁６の基部
を仕切壁体１の一側端面１Ａに押圧する為の押圧部であ
る。
【００１０】そして、前記圧力制御弁Ｐの上流通路４Ｂ
が吸気路４０Ａに向かう上流側負圧導入路３２Ａに接続
され、下流通路８Ｂがスローロック受圧室３０に向かう
下流側負圧導入路３２Ｂに接続される。これが図１に示
される。
【００１１】そして本発明になるベーパーライザは、以
下の作用をなす。絞り弁４３の低開度時における一定開
度運転時において、吸気路４０内には一定負圧値以上の
大なる負圧が生起するもので、この大なる負圧は上流側
負圧導入路３２Ａ、上流通路４Ｂから圧力制御弁Ｐの上
流室ＰＡ内に導入される。そして、この大なる負圧が上
流室ＰＡ内にある逆止弁６に作用すると、逆時弁６は弁
孔２を開孔するもので、上流室ＰＡ内の大なる負圧は弁
孔２、下流室ＰＢ、下流通路８Ｂ、下流側負圧導入路３
２Ｂを介してベーパーライザＶのスローロック受圧室３
０内に導入される。この大なる負圧がスローロック受圧
室３０に作用することによると、スローロックダイヤフ
ラム２９は、スローロックスプリング１１のバネ力に抗
して図において左方へ移動し、これによってスローロッ
ク弁２８が１次燃料吐出路２７を開放保持する。以上に
よると、１次減圧室２２内の一次圧を有するガス燃料が
１次燃料吐出路２７、１次圧燃料導入路４８、アイドル
ポート４７を介して吸気路４０内に供給され、もって絞
り弁４３の低開度運転が行なわれる。尚、絞り弁４３の
中、高開度運転は前述の如く従来と同様に行なわれるの
で説明は省略する。
【００１２】次に絞り弁４３の低開度から絞り弁４３が
連続的に開閉されるスナップ動作時について説明する。
絞り弁４３が低開度より急激に吸気路４０を開放する
と、吸気路４０内を流れる空気流れが遅くなり負圧は大
きく低下（大気圧に近づく）し、一定負圧値以下とした
もので、この一定負圧値以下の負圧が上流側負圧導入路
３２Ａを介して圧力制御弁Ｐの上流室ＰＡに達する。こ
れによると上流室ＰＡ内の逆止弁６は負圧の低下によっ
て即座に弁孔２を閉塞するもので、一定負圧値以下の負
圧がスローロック受圧室３０内に達することがなく、ス
ローロック受圧室３０内の負圧を絞り弁４３の低開度運
転時における高負圧状態に維持し、その負圧が低下する
ことが抑止される。従って、スローロック弁２８は継続
して１次燃料吐出路２７を開放保持できるので、１次減
圧室２２内の１次圧を有するガス燃料を継続的にアイド
ルポート４７を介して吸気路４０内に供給できる。一
方、前記による絞り弁４３の開放状態から、スナップ動
作による絞り弁４３の低開度への閉弁動作によると、絞
り弁４３より下流側の吸気路４０Ａ内には一定負圧値以
上の大なる負圧が生起するもので、かかる大なる負圧が
圧力制御弁Ｐの逆止弁６に作用すると、前記において閉
弁状態にある逆止弁６は再び弁孔２を開放し、大なる負
圧が再びスローロック受圧室３０に作用し、前述の如く
スローロック弁２８が１次燃料吐出路２７を開放保持す
る。
【００１３】以上によると、絞り弁４３の低開度状態に
おいて、スローロック受圧室３０内には絞り弁４３より
下流側の吸気路４０Ａ内の一定負圧値以上の大なる負圧
が作用してスローロック弁２８が１次燃料吐出路２７を
開放保持し、又、絞り弁４３が低開度状態から急激に
中、高開度状態に開放された際、絞り弁４３より下流側
の吸気路４０Ａ内の負圧が一定負圧値以下に低下して
も、逆止弁６が即座に弁孔２を閉塞してスローロック受
圧室３０内に前記状態において導入された高い負圧を維
持することができたので、スローロック弁２８が１次燃
料吐出路２７を依然として開放保持でき、更に前記絞り
弁の中、高開度状態から絞り弁４３が低開度状態に戻さ
れた際、吸気路４０Ａ内には再び一定負圧値以上の負圧
が生起し、この負圧は逆止弁６を開放して弁孔２よりス
ローロック受圧室内へ導入され、スローロック弁２８が
１次燃料吐出路２７を開放保持できる。
【００１４】以上の如く、本発明になるベーパーライザ
によると、絞り弁４３を低開度から中、高開度に開放
し、再び絞り弁４３を低開度へ戻すスナップ動作時にお
いて、吸気路４０内の負圧が一定負圧値以下に低下して
も、スローロック受圧室３０内には一定負圧値以上の負
圧を常時確保できたもので、前記スナップ動作時におい
てアイドルポート４７より継続的にガス燃料を安定供給
でき、機関の運転性が阻害されることがない。
【００１５】又、圧力制御弁Ｐには弁孔２を迂回して上
流室ＰＡと下流室ＰＢとを連絡するバイパス通路３を設
け、該バイパス通路３に制御オリフィス７を設けたもの
で、これによると必要以上にスローロック受圧室３０内
の負圧を大なる負圧状態に保持することがない。例えば
スナップ動作をした後に機関を停止する場合、（これは
二輪車においてよく行なわれる動作である）スローロッ
ク受圧室３０内には前述の如く大なる負圧が保持され、
これによってスローロック弁が１次燃料吐出路２７を開
放保持し、機関の停止時にあっても依然として１次燃料
吐出路２７から１次圧を有する燃料がアイドルポート４
７より供給される。これに対し、本発明のベーパーライ
ザにあっては、バイパス通路３に制御オリフィス７が配
置され、スローロック受圧室３０内に保持される大なる
負圧が制御オリフィス７を介して徐々に大気側に放出さ
れ、スローロック受圧室３０内の負圧を一定時間経過し
た後に低下でき、スローロック弁２８にて１次燃料吐出
路２７を閉塞したので、１次圧を有するガス燃料がアイ
ドルポート４７より供給され続けることがない。尚、か
かる制御オリフィス７の孔径はスナップ動作時における
スローロック受圧室３０内の圧力保持特性及び機関停止
時におけるスローロック受圧室３０内の負圧解放特性よ
り最適に決定されるものである。又、前記逆止弁及び制
御オリフィスの構造は前記実施例に限定されるものでな
い。
【００１６】
【発明の効果】以上の如く、本発明になる内燃機関用の
ベーパーライザによると、１次減圧室から外部に向かっ
て開口する１次燃料吐出路に、該通路を吸気路内の負圧
に応じて開閉するスローロック弁が配置されるとともに
スローロック弁に開閉操作力を付与するスローロックダ
イヤフラムによって区分されるスローロック受圧室と吸
気路とを連絡する負圧導入路に圧力制御弁が配置され、
前記圧力制御弁を、吸気路内に生起する負圧が一定負圧
値以上において、弁孔によって区分される上流室と下流
室とを連通し、それ以下の負圧で弁孔を閉塞する逆止弁
と、弁孔を迂回して上流室と下流室を連絡するバイパス
通路に配置され、一定開口をもって常時連通する制御オ
リフィスと、によって形成したので、機関のスナップ動
作時において、安定したガス燃料を供給でき、良好な機
関の運転性を得ることができるとともにスナップ動作直
後に機関を停止した際等において無用なガス燃料の供給
を停止できるとともに混合気濃度が濃化傾向をなすこと
が抑止できる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for supplying a gaseous fuel such as liquefied petroleum gas (LPG) or compressed natural gas (CNG) to an internal combustion engine. The present invention relates to a vapor riser in which a gas fuel in a gas fuel source is reduced to a predetermined primary pressure in a primary pressure reducing chamber and is reduced to a substantially atmospheric pressure secondary pressure in a secondary pressure reducing chamber. 2. Description of the Related Art A conventional vaporizer V will be described with reference to FIG. Reference numeral 20 denotes a primary diaphragm that divides the housing B into a primary pressure regulating chamber 21 and a primary pressure reducing chamber 22. The primary diaphragm 20 is arranged in a reduced form in the primary pressure regulating chamber 21. Primary decompression chamber 2 by the spring force of the next spring 23
Pressed to two sides. Reference numeral 24 denotes a primary valve disposed at one end of a primary support rod 25 rotatably supported in the primary decompression chamber 22. The primary valve 24 is a fuel inflow passage opening to the primary decompression chamber 22. 26 is opened and closed. The other end of the first support rod 25 is locked to the primary diaphragm 20. Reference numeral 27 denotes a primary fuel discharge passage that opens outward from the primary pressure reducing chamber 22, and the primary fuel discharge passage is opened and closed by a slow lock valve 28. Reference numeral 29 denotes a slow lock diaphragm which is connected to the slow lock valve via a connecting rod 29A and applies an opening / closing operation force to the slow lock valve 28, and a slow lock pressure receiving chamber 30 defined by the slow lock diaphragm 29. Inside, a slow lock spring 31 for pressing the slow lock diaphragm 29 rightward in FIG. 4 is contracted. In other words, the slow lock spring 31 has the slow lock valve 28 of 1
It can be said that the next fuel discharge passage 27 is urged toward the closing side. Then, the negative pressure generated by the operation of the engine is introduced into the slow lock pressure receiving chamber 30 through the negative pressure introducing passage 32. In this example, the upstream side of the negative pressure introduction path 32 is connected to an intake path of a mixing body described later. Reference numeral 33 denotes a primary adjustment screw for adjusting and controlling the amount of gas fuel flowing through the primary fuel discharge passage 27, and a tapered needle valve portion is formed at the tip. Case B
Is further adjusted by a secondary diaphragm 34 to a secondary pressure regulating chamber 35.
And a second decompression chamber 36, and one
A secondary fuel inflow passage 37 connected to the next decompression chamber 22 and a secondary fuel discharge passage 38 facing the outside are opened. 39 is a second support rod rotatably supported in the secondary decompression chamber 36,
A secondary valve 40 for opening and closing the secondary fuel inflow passage 37 is disposed at one end of the second support rod 39, and the other end is locked by the secondary diaphragm 34. Also, the second support rod is 2
The secondary valve 41 is urged in the counterclockwise direction by the spring force of the next spring 41, whereby the secondary valve 40 is pressed to the side that closes the secondary fuel inflow passage 37. Then, liquefied petroleum gas (LPG) as gas fuel is supplied to the fuel inflow passage 26 of the vaporizer V. Liquefied petroleum gas (hereinafter LP)
G), about 5 kg in the gas fuel source T1
LPG having a pressure of / cm 2 is supplied directly to the fuel introduction channel 26. On the other hand, compressed natural gas (hereinafter referred to as CNG) can be used instead of LPG,
At this time, CNG having a pressure of about 200 kg / cm 2 in the gas fuel source T2 is reduced in pressure by about 6 kg / cm 2 by the primary regulator R.
NG is supplied to the fuel inflow passage 26. M is a mixing body which receives the supply of gas fuel from the vapor riser and supplies a mixture of air and gas fuel to the engine via an intake pipe (not shown). The mixing body M is provided with an intake passage 40 penetrating therethrough, and a mixer venturi portion 41 is formed upstream thereof. The intake passage is controlled to be opened and closed by a throttle valve 43 attached to a throttle valve shaft 42 rotatably supported by the mixing body M, while a plurality of main ports 4 are provided in the mixer venturi section 41.
The main port 44 is formed with an opening.
Is connected to a secondary pressure fuel introduction passage 46 through an annular groove 45 formed surrounding the mixer venturi portion 41. Reference numeral 47 denotes an idle port that opens to the intake passage 40A downstream of the throttle valve 43, and is connected to a primary pressure fuel introduction passage 48. The secondary pressure fuel introduction path is connected to the secondary fuel discharge path 38 of the vapor riser V, and the primary pressure fuel introduction path 48 is connected to the primary fuel discharge path 27. In the vaporizer V, the primary valve 24
The fuel inlet passage by a fuel pressure having a gas fuel itself (in the LPG about 5 kg / cm 2 of the fuel pressure, fuel pressure of about 6 kg / cm 2 In the CNG reduced in pressure by the primary regulator R) 26 is opened, and the gaseous fuel is supplied into the primary decompression chamber 22. Then, the pressure in the primary decompression chamber 22 becomes a predetermined pressure (for example, 0.3 kg / c).
m 2 ), the primary diaphragm 20
It moves toward the primary pressure regulating chamber 21 against the spring force of the next spring 23, whereby the first support rod 25 rotates counterclockwise, and the primary valve 24 closes the fuel inflow passage 26. 1
The gas fuel pressure in the next decompression chamber 22 can be adjusted to 0.3 kg / cm 2 . On the other hand, when the gas fuel pressure in the primary decompression chamber 22 is reduced to a pressure of 0.3 kg / cm 2 or less, the primary spring 23 moves the primary diaphragm 20 to the primary decompression chamber 22.
The first support rod 25 is rotated clockwise, and the primary valve 24 opens the fuel inflow passage 26. Accordingly, the gas fuel in a high pressure state is supplied from the fuel inflow passage 26 into the primary decompression chamber 22, whereby the gas fuel pressure in the primary decompression chamber 22 is again reduced to a predetermined value of 0.3 kg / cm.
2 can be returned. Thereafter, by repeatedly performing the operation of the primary valve, gas fuel having a predetermined primary pressure of 0.3 kg / cm 2 is maintained in the primary decompression chamber 22. . When the engine is started, a negative pressure is generated in the intake passage 40A downstream of the throttle valve 43 of the mixing body M, and the negative pressure is generated through the negative pressure introduction passage 32 to the slow lock pressure receiving chamber 30.
Introduced into. According to this, the slow lock diaphragm 29 moves to the left in the drawing against the spring force of the slow lock spring 31 (in other words, moves to the slow lock pressure receiving chamber 30 side), and the slow lock diaphragm 29 moves to the left. Is transmitted to the slow lock valve 28 by the connecting rod 29A, and the slow lock valve 28 opens the primary fuel discharge passage 27. According to the above, 1 having the primary pressure
The gas fuel in the secondary pressure reducing chamber 22 is
The gas fuel is supplied to the idle port 17 through the primary fuel discharge passage 27 and the primary pressure fuel introduction passage 48, whereby the engine is started and the low opening operation is performed. On the other hand, in the secondary pressure reducing chamber 36, the gas fuel is reduced to atmospheric pressure. As described above, the primary decompression chamber 2
Gas fuel pressure in 2 intended to be pressed 0.3 kg / cm 2 two tone, gas fuel having a pressure of 0.3 kg / cm 2 is applied to the 2 Tsugiben 40 via the secondary fuel inlet passage 37 And
The secondary valve 40 opens the secondary fuel inflow passage 37, and gaseous fuel is supplied into the secondary pressure reducing chamber 36. Here, the secondary decompression chamber 3
When the gas fuel pressure in the cylinder 6 rises above the atmospheric pressure, the secondary diaphragm 34 is displaced toward the secondary pressure regulating chamber 35, whereby the second support rod 39 is moved counterclockwise by the spring force of the secondary spring 41. Then, the secondary valve 40 closes the secondary fuel inflow passage 37, thereby returning the gas fuel pressure in the secondary pressure reducing chamber 36 to the atmospheric pressure. When the gaseous fuel pressure in the secondary pressure reducing chamber 36 falls below the atmospheric pressure, the secondary diaphragm 34 is displaced toward the secondary pressure reducing chamber 36 against the spring force of the secondary spring 41. The second support rod 39 rotates clockwise, and the secondary valve 44 opens the secondary fuel inflow passage 37, thereby returning the gas fuel pressure in the secondary pressure reducing chamber 36 to the atmospheric pressure. Thereafter, the secondary valve 40 repeats the above operation, whereby the gas fuel pressure in the secondary pressure reducing chamber 36 can be maintained at the atmospheric pressure as the secondary pressure. When the throttle valve 43 opens the intake passage 40 to a medium opening degree and a high opening degree, a high negative pressure corresponding to the throttle valve opening degree is generated in the mixer venturi section 41, and this negative pressure is A gas in an atmospheric state maintained in the secondary pressure reducing chamber 36 through the main port 44, the annular groove 45, the secondary pressure fuel introducing path 46, and the secondary fuel discharging path 38 to act on the secondary pressure reducing chamber 36. Fuel is sucked into the mixer venturi section 41 through the main port 44, whereby the inside of the throttle valve 43 and the high opening operation are performed. According to the conventional vapor riser, the operation of the engine during a snap operation in which the throttle valve is continuously opened and closed from a low opening to a high opening is performed. Sex may be impaired. This is for the following reason. When the throttle valve 43 is at a low opening degree, a large negative pressure is generated in the intake passage 40 </ b> A downstream of the throttle valve 43, and the large negative pressure is generated through the negative pressure introduction passage 32 and the slow lock pressure receiving chamber 30. Introduced within. According to the above description, the slow lock diaphragm 29 is displaced toward the slow lock pressure receiving chamber 30 against the spring force of the slow lock spring 31. According to this, the slow lock valve 28 opens the primary fuel discharge passage 27 and Gas fuel having a primary pressure in the secondary pressure reducing chamber 22 is supplied to the intake path 40 of the mixing body M via the idle port 47, whereby the throttle valve 43 is operated at a low opening degree. Then, when the throttle valve 43 is rapidly opened from the low opening degree state of the throttle valve 43, the negative pressure in the intake passage 40 is temporarily reduced (approaching the atmospheric pressure).
When the reduced negative pressure is introduced into the slow lock pressure receiving chamber 30 through the negative pressure introduction passage 32, the slow lock diaphragm 29
Due to the spring force of the secondary decompression chamber 36 (right side in the figure)
Move to According to the above description, the slow lock valve 28 moves rightward in the figure in synchronization with the slow lock diaphragm 29, closes the primary fuel discharge passage 27, and has a primary pressure flowing from the idle port 47 into the intake passage 40. The gas fuel supply will be temporarily stopped. Then, when a snap operation is performed in which the opening and closing operations of the throttle valve are continuously performed, the concentration of the gas-fuel mixture flowing in the intake passage 40 is diluted, and the engine speed falls below a predetermined speed. And the engine may stop. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and in a snap operation in which a throttle valve is continuously opened and closed from a low opening to a high opening, supply of gas fuel is cut off, The mixture concentration of is not diluted,
It is an object of the present invention to provide a vapor riser for an internal combustion engine that can obtain stable operation of the engine. In order to achieve the above object, a vaporizer for an internal combustion engine according to the present invention uses a gas fuel in a gas fuel source at a predetermined primary pressure in a primary pressure reducing chamber. In a vapor riser, the pressure is reduced to a secondary pressure of approximately atmospheric pressure in a secondary pressure reducing chamber; a primary fuel discharge passage opening from the primary pressure reducing chamber to the outside; A slow lock valve that opens and closes in response to a negative pressure is arranged, and a pressure control is applied to a negative pressure introduction passage that connects a slow lock pressure receiving chamber and an intake passage divided by a slow lock diaphragm that applies an opening and closing operation force to the slow lock valve. A valve is disposed, and when the negative pressure generated in the intake passage is equal to or higher than a predetermined negative pressure value, the pressure control valve communicates with the upstream chamber and the downstream chamber divided by the valve hole, and the valve is controlled at a negative pressure less than that. Check valve to close the hole And a control orifice that is arranged in a bypass passage that bypasses the valve hole and connects the upstream chamber and the downstream chamber, and that is always in communication with a fixed opening. When the throttle valve has a low opening, a large negative pressure generated in the intake passage acts on the check valve of the pressure control valve, and the check valve keeps the valve hole open. Therefore, a large negative pressure in the intake passage is introduced into the slow lock pressure receiving chamber through the valve hole and the negative pressure introducing passage, whereby the slow lock valve keeps the primary fuel discharge passage open and holds the primary fuel discharge chamber. Is supplied into the intake passage via the primary fuel discharge passage and the idle port. On the other hand, when the throttle valve is rapidly opened from the low opening state to the high opening state, the negative pressure in the intake passage is greatly reduced.When the reduced negative pressure acts on the check valve,
The check valve immediately closes the valve hole. According to the above, a large negative pressure is held in the slow lock pressure receiving chamber, and the slow lock valve still holds the primary fuel discharge passage open. Therefore, when the snap operation in which the throttle valve is continuously opened and closed is performed, the operation of the engine can be stably performed without temporarily stopping the supply of the gas fuel from the primary fuel discharge path. Can do it. On the other hand, a part of the large negative pressure in the slow lock pressure receiving chamber is slightly leaked from the downstream chamber to the upstream chamber via the bypass passage and the control orifice. Since it is weakened, it is possible to achieve an appropriate mixture concentration. An embodiment of a vaporizer for an internal combustion engine according to the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of a vaporizer for an internal combustion engine according to the present invention. FIG. 2 is a longitudinal sectional view of the pressure control valve used in FIG. FIG. 3 is a longitudinal sectional view taken along line AA of FIG.
The vaporizer according to the present invention is obtained by adding a pressure control valve P to a conventional vaporizer. Note that the same components as those in the related art are denoted by the same reference numerals, and description thereof is omitted. The pressure control valve P includes the following. (Especially, FIGS. 2 and 3
1) is a partition wall provided with one side end face 1A and the other side end face 1B, and from one side end face 1A to the other side end face 1
The valve hole 2 and the bypass passage 3 penetrate and are drilled toward B. The valve hole 2 and the bypass passage 3 are formed in parallel in the partition wall 1, and the valve hole 2 and the bypass passage 3 are not directly connected. 4 is one end face 1 of the partition wall 1
A. It is a bottomed cup-shaped upstream cover having a recess 4A, and an upstream passage 4B opens in the recess 4A. Reference numeral 5 denotes a thin plate-shaped control plate disposed on one side end surface 1A of the partition wall 1. The control plate 5 includes a check valve 6 that can open and close the valve hole 1 of the partition wall 1, and a bypass. A control orifice 7 is formed facing the passage 3. Specifically, the control plate 5 is formed of a thin stainless steel material having a thickness of, for example, about 0.5 mm, and the check valve 6 is
The control orifice 7 is formed by a small hole. The valve opening characteristics of the check valve 6 and the diameter of the control orifice 7 having a minute hole are determined by a test suitable for each engine. 8 is arranged on the other end surface 1B of the partition wall 1. It is a bottomed cup-shaped downstream cover having a recess 8A, and a downstream passage 8B opens in the recess 8A. A control plate 5 and an upstream cover 4 are arranged on one end 1A of the partition wall 1, and a downstream cover 8 is arranged on the other end 1B. In this state, the upstream cover 4, the control plate 5, the partition The wall 1 and the downstream cover 8 are integrally assembled by screws 9. According to the above description, the upstream chamber PA is formed by the one end face 1A of the partition wall 1 and the recess 4A of the upstream cover 4, and the other end face 1B and the recess 8 of the downstream cover 8 are formed.
A forms a downstream chamber PB, the upstream passage 4B opens in the upstream chamber PA, and the downstream passage 8B opens in the downstream chamber PB. The control plate 5 has its outer periphery fixedly supported by the one end face 1A of the partition wall 1 and the upstream cover 4. At this time, the check valve 6 is arranged facing the valve hole 2, and the control plate 5 is controlled. The orifice 7 is arranged facing the bypass passage 3.
Note that the control plate 5 is disposed in airtight contact with one side 1A of the partition wall 1, and a seal ring for maintaining the airtightness is provided.
Descriptions such as adhesion are omitted. Therefore, the valve hole 2 and the upstream chamber P
A is controlled to open and close only by the check valve 6, and the bypass passage 3 is connected to the upstream chamber PA only by the control orifice 7. Neither the control plate 5 nor the check valve 6 and the valve hole 2 communicate with each other, nor does the control orifice 7 and the bypass passage 3 communicate with each other. Reference numeral 4C denotes a pressing portion for pressing the base of the check valve 6 against one end surface 1A of the partition wall 1. The upstream passage 4B of the pressure control valve P
Is connected to the upstream negative pressure introduction path 32A toward the intake path 40A, and the downstream passage 8B is connected to the downstream negative pressure introduction path 32B toward the slow lock pressure receiving chamber 30. This is shown in FIG. The vaporizer according to the present invention has the following functions. When the throttle valve 43 is operated at a constant opening at a low opening, a large negative pressure that is equal to or greater than a constant negative pressure value is generated in the intake passage 40. 32A is introduced into the upstream chamber PA of the pressure control valve P from the upstream passage 4B. When the large negative pressure acts on the check valve 6 in the upstream chamber PA, the check valve 6 opens the valve hole 2, and the large negative pressure in the upstream chamber PA is reduced by the valve hole 2. , Downstream chamber PB, downstream passage 8B, downstream negative pressure introduction passage 3
Slow lock pressure receiving chamber 3 of vaporizer V via 2B
Introduced in 0. According to this large negative pressure acting on the slow lock pressure receiving chamber 30, the slow lock diaphragm 29 moves to the left in the drawing against the spring force of the slow lock spring 11, thereby causing the slow lock valve 28 to move. The primary fuel discharge passage 27 is kept open. According to the above, the gas fuel having the primary pressure in the primary pressure reducing chamber 22 is supplied into the intake path 40 through the primary fuel discharge path 27, the primary pressure fuel introduction path 48, and the idle port 47, and thus the throttle valve 43 is performed. Since the high opening operation of the throttle valve 43 is performed in the same manner as in the prior art as described above, the description is omitted. Next, a description will be given of a snap operation in which the throttle valve 43 is continuously opened and closed from the low opening degree of the throttle valve 43.
When the throttle valve 43 opens the intake passage 40 more rapidly than the low opening degree, the airflow flowing in the intake passage 40 is slowed down, the negative pressure is greatly reduced (approaching the atmospheric pressure), and the negative pressure is set to a fixed negative pressure value or less. The negative pressure equal to or lower than the predetermined negative pressure value reaches the upstream chamber PA of the pressure control valve P via the upstream negative pressure introducing passage 32A. According to this, the check valve 6 in the upstream chamber PA immediately closes the valve hole 2 due to the decrease in the negative pressure, and the negative pressure equal to or lower than the constant negative pressure value does not reach the slow lock pressure receiving chamber 30. The negative pressure in the slow lock pressure receiving chamber 30 is maintained at a high negative pressure state when the throttle valve 43 is operated at a low opening degree, and the negative pressure is prevented from lowering. Therefore, the slow lock valve 28 can continuously keep the primary fuel discharge passage 27 open, so that the gas fuel having the primary pressure in the primary pressure reducing chamber 22 is continuously supplied to the intake passage 40 through the idle port 47. Can be supplied. On the other hand, according to the closing operation of the throttle valve 43 to the low opening degree by the snap operation from the open state of the throttle valve 43 as described above, a large negative pressure equal to or more than a certain negative pressure value is present in the intake passage 40A downstream of the throttle valve 43. When such a large negative pressure acts on the check valve 6 of the pressure control valve P, the check valve 6 in the closed state opens the valve hole 2 again and becomes large. The negative pressure again acts on the slow lock pressure receiving chamber 30, and the slow lock valve 28 keeps the primary fuel discharge passage 27 open as described above. According to the above description, when the throttle valve 43 is in the low opening state, a large negative pressure greater than or equal to the predetermined negative pressure in the intake passage 40A downstream of the throttle valve 43 acts in the slow lock pressure receiving chamber 30. When the slow lock valve 28 keeps the primary fuel discharge passage 27 open and the throttle valve 43 is rapidly opened from the low opening state to the middle or high opening state, the intake air downstream of the throttle valve 43 is taken. Even if the negative pressure in the passage 40A drops below a certain negative pressure value, the check valve 6 immediately closes the valve hole 2 to maintain the high negative pressure introduced into the slow lock pressure receiving chamber 30 in the above state. Therefore, the slow lock valve 28 can still hold the primary fuel discharge path 27 open, and when the throttle valve 43 is returned from the high opening state to the low opening state in the throttle valve, In the intake passage 40A, a negative pressure equal to or higher than the predetermined negative pressure value is generated again. Stop valve 6 opens the introduced from the valve hole 2 to the slow locking pressure chamber, the slow lock valve 28 can be opened holds the primary fuel discharge passage 27. As described above, according to the vapor riser according to the present invention, when the throttle valve 43 is opened from a low opening to a medium opening and a high opening, and the throttle valve 43 is returned to a low opening again during the snap operation, the intake passage is closed. Even if the negative pressure in the pressure 40 falls below the predetermined negative pressure value, a negative pressure higher than the predetermined negative pressure value can always be ensured in the slow lock pressure receiving chamber 30. Gas fuel can be supplied stably continuously, and the operability of the engine is not hindered. The pressure control valve P is provided with a bypass passage 3 which bypasses the valve hole 2 and connects the upstream chamber PA and the downstream chamber PB. The bypass passage 3 is provided with a control orifice 7. According to this, the negative pressure in the slow lock pressure receiving chamber 30 is not maintained at a large negative pressure state more than necessary. For example, when the engine is stopped after performing the snap operation, a large negative pressure is held in the slow lock pressure receiving chamber 30 as described above (this is an operation often performed in a motorcycle).
As a result, the slow lock valve keeps the primary fuel discharge passage 27 open, and even when the engine is stopped, the fuel having the primary pressure still flows from the primary fuel discharge passage 27 to the idle port 4.
7. On the other hand, in the vapor riser of the present invention, the control orifice 7 is disposed in the bypass passage 3, and the large negative pressure held in the slow lock pressure receiving chamber 30 gradually increases through the control orifice 7 to the atmosphere side. The negative pressure in the slow lock pressure receiving chamber 30 can be reduced after a certain period of time has elapsed, and the primary fuel discharge passage 27 is closed by the slow lock valve 28. There will be no more supply. The diameter of the control orifice 7 is determined optimally based on the pressure holding characteristics in the slow lock pressure receiving chamber 30 during the snap operation and the negative pressure releasing characteristics in the slow lock pressure receiving chamber 30 when the engine is stopped. Further, the structures of the check valve and the control orifice are not limited to the above-described embodiment. As described above, according to the vapor riser for an internal combustion engine according to the present invention, the primary fuel discharge passage opening outward from the primary pressure reducing chamber is provided with the passage in the intake passage. A slow lock valve that opens and closes in response to a negative pressure is arranged, and a pressure control is applied to a negative pressure introduction passage that connects a slow lock pressure receiving chamber and an intake passage divided by a slow lock diaphragm that applies an opening and closing operation force to the slow lock valve. The valve is located,
When the negative pressure generated in the intake passage is equal to or higher than a predetermined negative pressure value, the pressure control valve communicates with the upstream chamber and the downstream chamber divided by the valve hole, and closes the valve hole with a negative pressure less than the reverse pressure. The control valve is formed by a stop valve and a control orifice which is arranged in a bypass passage which bypasses the valve hole and connects the upstream chamber and the downstream chamber, and which is always communicated with a constant opening. , It is possible to obtain good operability of the engine, to stop the supply of unnecessary gas fuel when the engine is stopped immediately after the snap operation, and to suppress the tendency of the mixture concentration to increase. .
【図面の簡単な説明】
【図１】本発明になる内燃機関用のベーパーライザの一
実施例を示す縦断面図。
【図２】図１に用いられる圧力制御弁の縦断面図。
【図３】図２のＡ−Ａ線における縦断面図。
【図４】従来の内燃機関用のベーパーライザを示す縦断
面図。
【符号の説明】
２ 弁孔
３ バイパス通路
６ 逆止弁
７ 制御オリフィス
２２ １次減圧室
２６ ２次減圧室
２７ １次燃料吐出路
２８ スローロック弁
２７ スローロックダイヤフラム
３０ スローロック受圧室
３２ 負圧導入路
Ｐ 圧力制御弁BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing one embodiment of a vapor riser for an internal combustion engine according to the present invention. FIG. 2 is a longitudinal sectional view of a pressure control valve used in FIG. FIG. 3 is a longitudinal sectional view taken along line AA of FIG. 2; FIG. 4 is a longitudinal sectional view showing a conventional vaporizer for an internal combustion engine. [Description of Signs] 2 Valve hole 3 Bypass passage 6 Check valve 7 Control orifice 22 Primary pressure reducing chamber 26 Secondary pressure reducing chamber 27 Primary fuel discharge path 28 Slow lock valve 27 Slow lock diaphragm 30 Slow lock pressure receiving chamber 32 Negative pressure Inlet path P Pressure control valve
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高田 美博 埼玉県和光市中央１−４−１ 株式会社本 田技術研究所内 (72)発明者 田中 弘志 埼玉県和光市中央１−４−１ 株式会社本 田技術研究所内 (72)発明者 田邉 和也 埼玉県和光市中央１−４−１ 株式会社本 田技術研究所内 (72)発明者 野中 達司 栃木県塩谷郡高根沢町宝積寺2000番地 株 式会社ケーヒン栃木開発センター内 (72)発明者 阪田 栄作 栃木県塩谷郡高根沢町宝積寺2000番地 株 式会社ケーヒン栃木開発センター内 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshihiro Takada 1-4-1 Chuo, Wako-shi, Saitama Field Technology Research Institute (72) Inventor Hiroshi Tanaka 1-4-1 Chuo, Wako-shi, Saitama Field Technology Research Institute (72) Inventor Kazuya Tanabe 1-4-1 Chuo, Wako-shi, Saitama Field Technology Research Institute (72) Inventor Tatsushi Nonaka 2000 Hozoji Temple, Takanezawa-cho, Shioya-gun, Tochigi Prefecture Keihin Tochigi Development Center (72) Inventor Eisaku Sakata 2000 Hozoji Temple, Takanezawa-cho, Shioya-gun, Tochigi Prefecture Keihin Tochigi Development Center
Claims (1)
２２にて所定の１次圧に減圧するとともに２次減圧室１
６にて略大気圧状態の２次圧に調圧するベーパーライザ
において；１次減圧室２２から外部に向かって開口する
１次燃料吐出路２７に、該通路を吸気路内の負圧に応じ
て開閉するスローロック弁２８が配置されるとともにス
ローロック弁２８に開閉操作力を付与するスローロック
ダイヤフラム２９によって区分されるスローロック受圧
室３０と吸気路４０とを連絡する負圧導入路３２に圧力
制御弁Ｐが配置され、前記圧力制御弁を、吸気路内に生
起する負圧が一定負圧値以上において、弁孔２によって
区分される上流室ＰＡと下流室ＰＢとを連通し、それ以
下の負圧で弁孔２を閉塞する逆止弁６と、弁孔２を迂回
して上流室ＰＡと下流室ＰＢを連絡するバイパス通路３
に配置され、一定開口をもって常時連通する制御オリフ
ィス７と、によって形成したことを特徴とする内燃機関
用のベーパーライザ。Claims: 1. A gas pressure in a gas fuel source is reduced to a predetermined primary pressure in a primary pressure reducing chamber, and a gas pressure in a secondary pressure reducing chamber is reduced.
In a vapor riser which regulates the secondary pressure to a substantially atmospheric pressure state at 6; a primary fuel discharge passage 27 which opens from the primary pressure reducing chamber 22 to the outside is connected to the primary fuel discharge passage 27 in accordance with a negative pressure in the intake passage. A slow lock valve 28 that opens and closes is disposed, and a pressure is applied to a negative pressure introduction passage 32 that connects a slow lock pressure receiving chamber 30 and an intake passage 40 separated by a slow lock diaphragm 29 that applies an opening and closing operation force to the slow lock valve 28. A control valve P is disposed to communicate the pressure control valve with the upstream chamber PA and the downstream chamber PB separated by the valve hole 2 when the negative pressure generated in the intake passage is equal to or higher than a predetermined negative pressure value. A check valve 6 that closes the valve hole 2 by the negative pressure, and a bypass passage 3 that bypasses the valve hole 2 and connects the upstream chamber PA and the downstream chamber PB.
And a control orifice 7 which is arranged at a constant opening and communicates constantly with a fixed opening.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001283497A JP4096536B2 (en) | 2001-09-18 | 2001-09-18 | Vaporizer for internal combustion engines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001283497A JP4096536B2 (en) | 2001-09-18 | 2001-09-18 | Vaporizer for internal combustion engines |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003090268A true JP2003090268A (en) | 2003-03-28 |
| JP4096536B2 JP4096536B2 (en) | 2008-06-04 |
Family
ID=19106976
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001283497A Expired - Fee Related JP4096536B2 (en) | 2001-09-18 | 2001-09-18 | Vaporizer for internal combustion engines |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4096536B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006299958A (en) * | 2005-04-21 | 2006-11-02 | ＴＩ Ｗａｌｂｒｏ Ｊａｐａｎ株式会社 | Regulator for gas engine |
| JP2008255830A (en) * | 2007-04-02 | 2008-10-23 | Walbro Japan Inc | Mixture device for gaseous fuel and air |
| KR100958878B1 (en) | 2008-02-29 | 2010-05-20 | 피엔케이산업(주) | Controller for idling of vaporizer for a LPG vehicle |
| CN105443979A (en) * | 2014-08-29 | 2016-03-30 | 西安德森新能源装备有限公司 | A water-bath type vaporizer and a vehicle gas-supplying system of liquefied natural gas |
-
2001
- 2001-09-18 JP JP2001283497A patent/JP4096536B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006299958A (en) * | 2005-04-21 | 2006-11-02 | ＴＩ Ｗａｌｂｒｏ Ｊａｐａｎ株式会社 | Regulator for gas engine |
| JP2008255830A (en) * | 2007-04-02 | 2008-10-23 | Walbro Japan Inc | Mixture device for gaseous fuel and air |
| KR100958878B1 (en) | 2008-02-29 | 2010-05-20 | 피엔케이산업(주) | Controller for idling of vaporizer for a LPG vehicle |
| CN105443979A (en) * | 2014-08-29 | 2016-03-30 | 西安德森新能源装备有限公司 | A water-bath type vaporizer and a vehicle gas-supplying system of liquefied natural gas |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4096536B2 (en) | 2008-06-04 |
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