JPH03145565A - Fuel feeding device for engine - Google Patents
Fuel feeding device for engineInfo
- Publication number
- JPH03145565A JPH03145565A JP28257989A JP28257989A JPH03145565A JP H03145565 A JPH03145565 A JP H03145565A JP 28257989 A JP28257989 A JP 28257989A JP 28257989 A JP28257989 A JP 28257989A JP H03145565 A JPH03145565 A JP H03145565A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- pressure
- negative pressure
- valve
- chamber
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 137
- 230000001105 regulatory effect Effects 0.000 claims abstract description 33
- 239000002828 fuel tank Substances 0.000 claims abstract description 9
- 230000001276 controlling effect Effects 0.000 abstract 1
- 239000012528 membrane Substances 0.000 description 7
- 230000035485 pulse pressure Effects 0.000 description 6
- 230000033228 biological regulation Effects 0.000 description 4
- 238000006073 displacement reaction Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000005192 partition Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000036544 posture Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- HOXINJBQVZWYGZ-UHFFFAOYSA-N fenbutatin oxide Chemical compound C=1C=CC=CC=1C(C)(C)C[Sn](O[Sn](CC(C)(C)C=1C=CC=CC=1)(CC(C)(C)C=1C=CC=CC=1)CC(C)(C)C=1C=CC=CC=1)(CC(C)(C)C=1C=CC=CC=1)CC(C)(C)C1=CC=CC=C1 HOXINJBQVZWYGZ-UHFFFAOYSA-N 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Landscapes
- Fuel-Injection Apparatus (AREA)
- Control Of The Air-Fuel Ratio Of Carburetors (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
本発明は小排気量のエンジンに燃料(ガソリン)を供給
する装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for supplying fuel (gasoline) to a small displacement engine.
[従来の技術]
小形車両、産業機械、発電機などを駆動する比較的小排
気量のエンジンに燃料を供給する手段として広く用いら
れている気化器の内で、固定ベンチュリ気化器は低速燃
料と主燃料とを別通路で供給するので燃料のつながりが
不安定になりやすいとともに通路構成が複雑であり、可
変ベンチュリ気化器はベンチュリピストンとその案内な
どきわめて高い加工精度を要求する個所が多い、などの
問題をもっている。また、燃料調整手段が浮子式のもの
は大きな傾斜に対応できず、腹式のものはさまざまな姿
勢に対応できる反面燃料の制御精度がよくない、などの
問題がある。[Prior Art] Among the carburetors that are widely used as a means of supplying fuel to relatively small displacement engines that drive small vehicles, industrial machinery, generators, etc., fixed venturi carburetors are used for low-speed fuel and Because the main fuel is supplied through a separate passage, the fuel connection tends to be unstable and the passage configuration is complicated.Variable venturi carburetors have many parts that require extremely high machining precision, such as the venturi piston and its guide. I have a problem. In addition, float-type fuel adjustment means cannot cope with large inclinations, and belly-type ones can cope with various postures, but the fuel control accuracy is poor.
一方、ベンチュリ負圧などで燃料を吸気路に吸出す前記
の気化器に対して、第二次世界大戦中に航空機エンジン
用気化器の結氷対策として実用化されたいわゆる噴射気
化器がある。この気化器はベンデイックス社製のストロ
ンバーブ型気化器が広く知られており、ベンチュリ入口
動圧とベンチュリ負圧との差圧力で駆動される燃料圧力
制御弁、絞り弁に連動する燃料流量制御弁、ベンチュリ
負圧で駆動される燃料噴射弁を経て燃料を正圧力で吸気
路に噴射するものである。On the other hand, in contrast to the above-mentioned carburetor that sucks fuel into the intake passage using a venturi negative pressure, there is a so-called injection carburetor that was put into practical use during World War II as a countermeasure against freezing in aircraft engine carburetors. The Strombarb type carburetor manufactured by Bendex is widely known as this carburetor, and the fuel pressure control valve is driven by the differential pressure between the venturi inlet dynamic pressure and the venturi negative pressure, and the fuel flow control valve is linked to the throttle valve. , fuel is injected into the intake passage at positive pressure via a fuel injection valve driven by venturi negative pressure.
そして、このようないわゆる噴射気化器はさまざまな姿
勢に対して燃料の制御精度が高いという利点をもってい
る反面、燃料通路に前記三つの弁が直列に配置され、更
に始動や加速のための燃料供給手段が別途に設けられて
いるため燃料系統がきわめて複雑であるという欠点をも
っているのを改善し、燃料通路には燃料圧力調整手段の
みを配置した構成の燃料供給装置が特開平1−3203
1号公報に開示されている。Although such a so-called injection carburetor has the advantage of highly accurate fuel control in various postures, the three valves mentioned above are arranged in series in the fuel passage, and the fuel supply for starting and acceleration is difficult. Japanese Patent Laid-Open No. 1-3203 discloses a fuel supply device having a structure in which only a fuel pressure regulating means is disposed in the fuel passage, which improves the drawback that the fuel system is extremely complicated due to the provision of a separate means.
It is disclosed in Publication No. 1.
前記公報に開示されている技術は本発明の発明者、特許
出願人が提供したものであって、燃料をほぼ一定の正圧
力に調整して吸気路へ開口した主ノズルに送る燃料圧力
調整器と、ベンチュリ負圧と吸気マニホルド負圧との差
圧力に応じて主ノズルの有効面積を変える計量ニードル
を動作させエンジン吸気量に応じて有効面積を増減させ
る燃料流量調整器とを具えている。The technology disclosed in the above-mentioned publication was provided by the inventor and patent applicant of the present invention, and is a fuel pressure regulator that adjusts fuel to a substantially constant positive pressure and sends it to a main nozzle that opens into an intake passage. and a fuel flow regulator that operates a metering needle that changes the effective area of the main nozzle in response to the differential pressure between the venturi negative pressure and the intake manifold negative pressure to increase or decrease the effective area in accordance with the engine intake air amount.
ところが、燃料圧力調整器の燃料をほぼ一定の正圧力に
維持させる調圧室は、燃料ポンプから送られてくる燃料
を調圧室の燃料圧力に応じて制御させるように(至)く
ダイヤフラムによって大気から仕切られている密閉構造
であるので、調圧室で一時的に停滞する燃料から気泡が
分離したときや燃料蒸気を発生したとき、これらが調圧
室の上部に溜ってダイヤフラムの動きを変調させ、燃料
圧力を適正に制御することができなくなるという不都合
を生じる。However, the pressure regulating chamber that maintains the fuel in the fuel pressure regulator at a nearly constant positive pressure is equipped with a diaphragm that controls the fuel sent from the fuel pump according to the fuel pressure in the pressure regulating chamber. Since it has a sealed structure that is separated from the atmosphere, when air bubbles separate from the temporarily stagnant fuel in the pressure regulation chamber or fuel vapor is generated, these accumulate in the upper part of the pressure regulation chamber and prevent the movement of the diaphragm. This causes the problem that the fuel pressure cannot be properly controlled.
[発明が解決しようとする課題]
本発明はこのように燃料圧力調整器の調圧室に空気や燃
料蒸気が溜って燃料圧力を適正に制御できなくなるとい
う前記技術がもっている課題を解決しようとするもので
あって、燃料圧力調整器の正常な機能を損わずに調圧室
から空気や燃料蒸気を排出することができる燃料供給装
置を提供することを目的とする。[Problems to be Solved by the Invention] The present invention thus seeks to solve the problem that the above-mentioned technology has, in which air and fuel vapor accumulate in the pressure regulating chamber of the fuel pressure regulator, making it impossible to properly control the fuel pressure. It is an object of the present invention to provide a fuel supply device that can discharge air and fuel vapor from a pressure regulating chamber without impairing the normal function of a fuel pressure regulator.
[課題を解決するための手段]
本発明は固定ベンチュリおよび絞り弁を有する吸気路と
、前記吸気路に開口し計量ニードルにより有効面積が可
変の主ノズルと、燃料をほぼ一定の正圧力に調整して前
記主ノズルに送る燃料圧力調整器と、ベンチュリ負圧と
絞り弁の側方またはその下流側の吸気負圧との差圧力に
応じ゛て前記計量ニードルを動作させエンジン吸気量に
ほぼ対応して前記主ノズルの有効面積を変化させる燃料
調整器とを具えたエンジンの燃料供給装置がもっている
前記課題を解決するため次の手段を講じた。[Means for Solving the Problems] The present invention includes an intake passage having a fixed venturi and a throttle valve, a main nozzle that opens into the intake passage and whose effective area is variable with a metering needle, and adjusts the fuel to a substantially constant positive pressure. and a fuel pressure regulator that sends the fuel to the main nozzle, and operates the metering needle in accordance with the differential pressure between the venturi negative pressure and the intake negative pressure on the side of the throttle valve or downstream thereof, so as to correspond approximately to the engine intake air amount. In order to solve the above-mentioned problems of an engine fuel supply system including a fuel regulator that changes the effective area of the main nozzle, the following measures have been taken.
即ち、前記燃料圧力調整器の燃料をほぼ一定の正圧力に
維持させる調圧室の高所に燃料タンクに達する戻し通路
を開口させ、燃料流量を制限する絞りを前記戻し通路に
設けた。That is, a return passage that reaches the fuel tank is opened at a high point in the pressure regulating chamber that maintains the fuel in the fuel pressure regulator at a substantially constant positive pressure, and a throttle that restricts the fuel flow rate is provided in the return passage.
或いは、温度が低いとき閉じるがまたは小さい開度とさ
れ温度が高いとき大きく開く温度弁を絞りに代えて戻し
通路に設けた。Alternatively, a temperature valve that closes when the temperature is low and has a small opening and opens wide when the temperature is high is provided in the return passage instead of the throttle.
[作用コ
調圧室で燃料中の気泡が分離し或いは燃料蒸気が発生し
たとき、これらは高所に接続した戻し通路によって直ち
に排出され調圧室の燃料圧力を狂わせない、絞りはエン
ジンが要求する燃料の一部が必要以上に戻し通路に流れ
るのを防ぐ、また、温度弁は高温時に大量に発生する燃
料蒸気を自由に排出させる。[Effect: When air bubbles in the fuel separate or fuel vapor is generated in the pressure regulating chamber, these are immediately discharged through a return passage connected to a high place to prevent the fuel pressure in the pressure regulating chamber from going out of order. The temperature valve prevents a portion of the fuel from flowing into the return passage more than necessary, and also allows the fuel vapor, which is generated in large quantities at high temperatures, to be freely discharged.
[実施例] 図面を参照して本発明の詳細な説明する。[Example] The present invention will be described in detail with reference to the drawings.
本体lの竪方向へ延びる単一の吸気路2に固定ベンチュ
リ3と絞り弁4とが設置されているとともに、この本体
lの外側面に燃料ポンプ5、燃料圧力調整器25、燃料
流量調整器55が設けられている。A fixed venturi 3 and a throttle valve 4 are installed in a single intake passage 2 extending in the vertical direction of the main body l, and a fuel pump 5, a fuel pressure regulator 25, and a fuel flow regulator are installed on the outer surface of the main body l. 55 are provided.
燃料ポンプ5は第5図を参照して1本体1の一つの側面
にダイヤプラムからなるポンプ膜6、ポンプ胴体7、ダ
イヤフラムからなる仕切膜8゜カバー9を順に重ねて止
ねじにより一体に締付は固定し、本体1とポンプ膜6と
の間をポンプばね10が装入されたパルス室11.ポン
プ膜6とポンプ胴体7との間をポンプ室12、ポンプ胴
体7と仕切膜8との開会吸込室13および吐出室14、
仕切膜8とカバー9との間を大気室15としたよく知ら
れているパルス式ダイヤフラムポンプであって5エンジ
ンのクランクケースに発生したパルス圧をパルス圧通路
16によってパルス室11に導入しポンプ膜6を往復動
させて燃料入口17から吸込室13に入った燃料を入口
逆止弁18よリポンプ室12に吸込み、次で出口逆止弁
19より吐出室14に吐出することも従来のものと同じ
である。尚、入口逆止弁18と出口逆止弁19はゴム板
で作られ、ポンプ胴体7にリベット2oによって片持ち
式に支持されている。Referring to FIG. 5, the fuel pump 5 is constructed by stacking a pump membrane 6 made of a diaphragm, a pump body 7, a partition membrane 8° made of a diaphragm, and a cover 9 in this order on one side of the main body 1, and tightening them together with a set screw. The attachment is fixed, and a pulse chamber 11. in which a pump spring 10 is inserted is inserted between the main body 1 and the pump membrane 6. A pump chamber 12 is formed between the pump membrane 6 and the pump body 7, a suction chamber 13 and a discharge chamber 14 are formed between the pump body 7 and the partition membrane 8,
This is a well-known pulse type diaphragm pump that has an atmospheric chamber 15 between a partition membrane 8 and a cover 9, and the pulse pressure generated in the crankcase of the engine is introduced into the pulse chamber 11 through a pulse pressure passage 16. It is also conventional to reciprocate the membrane 6 to suck the fuel that has entered the suction chamber 13 from the fuel inlet 17 into the re-pump chamber 12 through the inlet check valve 18 and then discharge it into the discharge chamber 14 through the outlet check valve 19. is the same as Incidentally, the inlet check valve 18 and the outlet check valve 19 are made of a rubber plate, and are supported by the pump body 7 in a cantilevered manner by a rivet 2o.
燃料圧力調整器25は第5.6図を参照して、本体Iの
前記とは別の側面に配置された圧力調整弁26と調圧室
36とを有している。圧力調整弁26は燃料ポンプ5の
吐出室14と燃料導入路21によって接続された弁室2
7、弁室27に装入された弁体28および弁ばね29、
弁座30を有しており、弁室27と調圧室36とを連通
する弁座口31が弁体28によって開閉される。弁体2
8の後方へ延びる案内桁32は気化器本体1に固着され
て弁室27を塞いだプラグ33の案内孔34に密嵌して
弁体28を直線往復動させ、弁体28の前方へ延びる作
動術35は弁座口31を緩く貫通して調圧室36に突出
しダイヤフラム37に接している。このダイヤフラム3
7は本体lに調整器胴体38と重ねて一体に固定されて
おり、ダイヤフラム37と調整器胴体38との間は大気
室39を形成し調圧ばね40が装入されている。Referring to FIG. 5.6, the fuel pressure regulator 25 has a pressure regulating valve 26 and a pressure regulating chamber 36 arranged on a side surface of the main body I different from the above. The pressure regulating valve 26 is a valve chamber 2 connected to the discharge chamber 14 of the fuel pump 5 by a fuel introduction passage 21.
7. Valve body 28 and valve spring 29 inserted into valve chamber 27;
It has a valve seat 30 , and a valve seat opening 31 that communicates the valve chamber 27 and the pressure regulating chamber 36 is opened and closed by the valve body 28 . Valve body 2
The guide spar 32 extending toward the rear of the valve body 8 is tightly fitted into the guide hole 34 of the plug 33 that is fixed to the carburetor body 1 and closes the valve chamber 27, causing the valve body 28 to reciprocate linearly, and extending toward the front of the valve body 28. The actuator 35 loosely passes through the valve seat opening 31 and protrudes into the pressure regulating chamber 36 and is in contact with the diaphragm 37 . This diaphragm 3
7 is fixed to the main body 1 overlappingly with the regulator body 38, and an atmospheric chamber 39 is formed between the diaphragm 37 and the regulator body 38, and a pressure regulating spring 40 is inserted therein.
圧力調整弁26の弁体28は調圧室36の燃料圧力と弁
ばね29および調圧ばね40のばね荷重とによって定ま
るダイヤフラム37の位置に応じて弁座口31を開閉す
るものであって、調圧室36の燃料圧力が高くなると閉
弁し低くなると開弁して燃料ポンプ5から弁室27に送
られてきた燃料壱〇。The valve body 28 of the pressure regulating valve 26 opens and closes the valve seat port 31 according to the position of the diaphragm 37 determined by the fuel pressure in the pressure regulating chamber 36 and the spring loads of the valve spring 29 and the pressure regulating spring 40. When the fuel pressure in the pressure regulating chamber 36 becomes high, the valve closes, and when it becomes low, the valve opens, and the fuel 1 is sent from the fuel pump 5 to the valve chamber 27.
05〜0.2kg/cm程度の範囲内の一定正圧力に調
整し、調圧室36の燃料をこの範囲内の正圧力に維持す
る。The fuel pressure in the pressure regulating chamber 36 is maintained at a constant positive pressure within this range.
調整器胴体38の外側には保護カバー41がねじ42に
よって取外し可能に固定してあり、これらに囲まれた空
間は調整器胴体38にねじ43によって片持ち式に取付
けた板状のバイメタル44を内蔵したバイメタル室45
を形成している。このバイメタル44の自由端部は調整
器胴体38を貫通してダイヤフラム37に接するバイメ
タルロッド46が結合されている。バイメタル44は温
度が低いときバイメタルロッド46を押してダイヤフラ
ム37を調圧室36の方へ移動させ、圧力調整弁26を
大きく開かせて燃料ポンプ5から送られてくる燃料を大
量に調圧室36に導入し、燃料圧力を高くするように働
く、温度が高いときバイメタルロッド46はダイヤフラ
ム37から離れてダイヤフラム37を正常な位置に戻し
て燃料を前記範囲内の一定正圧力に調整させる。A protective cover 41 is removably fixed to the outside of the regulator body 38 with screws 42, and the space surrounded by these covers a plate-shaped bimetal 44 that is cantilevered to the regulator body 38 with screws 43. Built-in bimetal chamber 45
is formed. A bimetal rod 46 that passes through the regulator body 38 and contacts the diaphragm 37 is connected to the free end of the bimetal 44 . When the temperature is low, the bimetal 44 pushes the bimetal rod 46 to move the diaphragm 37 toward the pressure regulating chamber 36, widening the pressure regulating valve 26, and transferring a large amount of fuel sent from the fuel pump 5 to the pressure regulating chamber 36. When the temperature is high, the bimetallic rod 46 separates from the diaphragm 37 and returns the diaphragm 37 to its normal position to adjust the fuel to a constant positive pressure within the range.
調圧室36の燃料は第4.6図を参照して、本体lに形
成された燃料通路47を通り、固定ベンチュリ3の最狭
部に向かって突出した主ノズル(またはニードルジェッ
ト〉48の先端から噴射し、吸入空気と混合してエンジ
ンに供給される。Referring to FIG. 4.6, the fuel in the pressure regulating chamber 36 passes through a fuel passage 47 formed in the main body l, and enters a main nozzle (or needle jet) 48 that protrudes toward the narrowest part of the fixed venturi 3. It is injected from the tip, mixes with intake air, and is supplied to the engine.
燃料通路47は電磁弁49によってエンジンが運転され
ているとき開くがエンジンが停止すると閉じられる。The fuel passage 47 is opened by a solenoid valve 49 when the engine is running, but is closed when the engine is stopped.
燃料通路47は調圧室36の低い所に開口しておす、調
圧室36の最も高い所には図示しない燃料タンクに達す
る戻し通路50が開口している。The fuel passage 47 opens at a lower part of the pressure regulation chamber 36, and a return passage 50 which reaches a fuel tank (not shown) opens at the highest part of the pressure regulation chamber 36.
次に、第4.5図を参照して、燃料流量調整器55は本
体1の前記とは更に別の側面にダイヤフラム56を挟ん
で固定されたハウジング57と、このハウジング57に
設置した負圧制御弁80とを有している。ダイヤフラム
56のハウジング57側は第一負圧室58を形成し、本
体1側は第二負圧室59を形成しており、第一負圧室5
8は固定ベンチュリ3の最狭部に開口した第一負圧路6
0および絞り99を有していて燃料ポンプ5のパルス室
11に開口した補助負圧路61のいずれかと負圧制御弁
80によって接続される。第二負圧室59はアイドル位
置における絞り弁4の側方で吸気路2に開口しておりそ
して絞り69を有する第二負圧路62が接続されており
、更に第一負圧室58と第二負圧室59とにはダイヤフ
ラム56を押す押圧ばね63とバランスばね64とがそ
れぞれ装入されている。Next, referring to FIG. 4.5, the fuel flow regulator 55 includes a housing 57 fixed to another side of the main body 1 with a diaphragm 56 in between, and a negative pressure installed in the housing 57. It has a control valve 80. The housing 57 side of the diaphragm 56 forms a first negative pressure chamber 58, the main body 1 side forms a second negative pressure chamber 59, and the first negative pressure chamber 5
8 is a first negative pressure path 6 opened at the narrowest part of the fixed venturi 3
0 and an auxiliary negative pressure path 61 having a throttle 99 and opening into the pulse chamber 11 of the fuel pump 5 by a negative pressure control valve 80 . The second negative pressure chamber 59 opens into the intake passage 2 on the side of the throttle valve 4 in the idle position, is connected to a second negative pressure passage 62 having a throttle 69, and is further connected to the first negative pressure chamber 58. A pressure spring 63 and a balance spring 64 that press the diaphragm 56 are inserted into the second negative pressure chamber 59, respectively.
第一負圧路60は第3.4.7図を参照してアイドル位
置における絞り弁4の前記と反対の側方で吸気路2に開
口した第一補正通路65と、固定ベンチュリ3の上流側
で吸気路2に開口した第二補正通路67とを有している
。これらの補正通路65.67は絞り66.68をもっ
ており、ベンチュリ負圧が急激に変化しても第一負圧路
60を通って第一負圧室58に入るまでに圧力変化をや
わらげるように働き、その結果ダイヤフラム56は衝撃
的に動かされることがない。Referring to FIG. 3.4.7, the first negative pressure passage 60 includes a first correction passage 65 that opens into the intake passage 2 on the opposite side of the throttle valve 4 in the idle position, and a first correction passage 65 that opens into the intake passage 2 upstream of the fixed venturi 3. It has a second correction passage 67 that opens into the intake passage 2 on the side. These correction passages 65 and 67 have throttles 66 and 68, so that even if the venturi negative pressure changes suddenly, the pressure change is softened until it passes through the first negative pressure path 60 and enters the first negative pressure chamber 58. so that the diaphragm 56 is not moved impulsively.
第二負圧室59は第4,8図を参照して、第二負圧路6
2のほかに大気例えば図示しないエアクリーナの内部に
開口した補正通路70が接続されており、この補正通路
70は大気取入れ側で二つに分岐していて、その第一分
岐路71には本体1に外部から手動で調整可能にねじ込
んだ調整ねじ72の先端の針片73が差込まれ、第二分
岐路74には温度弁75が設けられている。温度弁75
は片持ち式の板状のバイメタル76の自由端に取付けた
針状の弁体77を有しており、温度が低いとき弁孔78
を大きく開き温度が高いとき閉じる。Referring to FIGS. 4 and 8, the second negative pressure chamber 59 is connected to the second negative pressure path 6.
In addition to the main body 1, a correction passage 70 is connected to the atmosphere, for example, the inside of an air cleaner (not shown), and this correction passage 70 is branched into two on the air intake side. A needle piece 73 at the tip of an adjustment screw 72 screwed in manually and adjustable from the outside is inserted into the second branch passage 74, and a temperature valve 75 is provided in the second branch passage 74. temperature valve 75
has a needle-shaped valve body 77 attached to the free end of a cantilevered plate-shaped bimetal 76, and when the temperature is low, the valve hole 78
Open wide and close when the temperature is high.
(’J圧制御弁80は第5,9図を参照して、弁室81
、弁室81の両側に向かい合せに設けた弁座82.83
、弁室81に内蔵された弁体84.戻しばね85を有し
ており、第一の弁座82は第一負圧路60の弁室81へ
の開口を囲んでいるとともに第二の弁座83は補助負圧
路61の弁室81への開口を囲んでいる。戻しばね85
は弁体84を第二の弁座83に押付けて補助負圧路61
を閉じ、第一負圧路60を弁室81、出口路86を経て
第一負圧室58に連通させるように働く。(For the J pressure control valve 80, refer to Figures 5 and 9.
, valve seats 82 and 83 provided facing each other on both sides of the valve chamber 81.
, a valve body 84 built into the valve chamber 81 . The first valve seat 82 surrounds the opening of the first negative pressure path 60 to the valve chamber 81, and the second valve seat 83 surrounds the opening of the auxiliary negative pressure path 61 to the valve chamber 81. surrounding the opening to. Return spring 85
presses the valve body 84 against the second valve seat 83 to open the auxiliary negative pressure path 61
, and serves to communicate the first negative pressure passage 60 with the first negative pressure chamber 58 via the valve chamber 81 and the outlet passage 86.
第二の弁座83と補助負圧路61の一部とはハウジング
57に固定した案内片87に形成されており、弁体84
から延びるロッド89が補助負圧路61を緩く貫通しそ
の前方で案内片87の案内孔88を気密に貫通して大気
室90に突出している。大気室90はハウジング57の
くぼみによって形成され、その開放端面はカバー91と
重ねてハウジング57に一体に固定したダイヤフラム9
2によって塞がれているが、空気フィルタ110を有す
る開口111によって大気に連通している(第2図)、
カバー91とダイヤフラム92とに囲まれた部分は負圧
室93を形成し、始動ばね94が装入されているととも
に、吸気路2の絞り弁4よりも下流側の部分と絞り95
を有する負圧通路96によって接続されている。The second valve seat 83 and a part of the auxiliary negative pressure path 61 are formed on a guide piece 87 fixed to the housing 57, and the valve body 84 is formed on a guide piece 87 fixed to the housing 57.
A rod 89 extending from the auxiliary negative pressure path 61 loosely passes through the guide hole 88 of the guide piece 87 in front thereof in an airtight manner and projects into the atmospheric chamber 90 . The atmospheric chamber 90 is formed by a recess in the housing 57, and its open end surface is covered with a diaphragm 9 that is integrally fixed to the housing 57, overlapping the cover 91.
2, but communicates with the atmosphere by an opening 111 with an air filter 110 (FIG. 2),
A portion surrounded by the cover 91 and the diaphragm 92 forms a negative pressure chamber 93, in which a starting spring 94 is inserted, and a portion of the intake path 2 downstream of the throttle valve 4 and the throttle 95.
They are connected by a negative pressure passage 96 having a .
燃料流量調整器55のダイヤフラム56の中心部には計
量ニードル79が固着されており、この計量ニードル7
9は第二負圧室59を横切り案内23を貫通して固定ベ
ンチュリ3の反対側に位置する主ノズル48に差込まれ
ている。計量ニードル79の先端の前方には、本体lに
外部から手動で調整可能にねじ込んだねじ97の先端に
設けたストッパ98が主ノズル48の後方において燃料
通路47に突出して配置されている。A metering needle 79 is fixed to the center of the diaphragm 56 of the fuel flow regulator 55.
9 crosses the second negative pressure chamber 59 , passes through the guide 23 , and is inserted into the main nozzle 48 located on the opposite side of the fixed venturi 3 . In front of the tip of the metering needle 79, a stopper 98 is disposed at the tip of a screw 97 that is screwed into the main body 1 so as to be manually adjustable from the outside, and protrudes into the fuel passage 47 behind the main nozzle 48.
計量ニードル79はエンジンの通常の運転状態で第一負
圧路60によって第一負圧室58に導入されたベンチュ
リ負圧、第二負圧路62によって第二負圧室59に導入
された絞り弁4の側方の吸気負圧、押圧ばね63および
バランスばね64の荷重によって定まるダイヤフラム5
6の位置に応じて直線往復動し、主ノズル48の有効面
積を変えてエンジンに供給される燃料流量を変える。即
ち、絞り弁4がアイドル位置のときおよび小開度のとき
第二負圧路62の吸気路2に開口したボート62aには
高い負圧が発生しており、ベンチュリ負圧は低いのでダ
イヤフラム56は第二負圧室59の方へ大きく移動して
主ノズル48の有効面積を小さくする。絞り弁4が大き
く開くとベンチュリ負圧と絞り弁4の側方の吸気負圧と
の差が小さくなり、成る開度以上ではベンチュリ負圧の
方が高くなるのでダイヤフラム56は第一負圧室58の
方へ次第に大きく移動して主ノズル48の有効面積を大
きくする。このようなダイヤフラム56の動きによって
、吸入空気量と燃料流量とを基本的に比例させ空燃比を
一定とすることができる。The metering needle 79 controls the venturi negative pressure introduced into the first negative pressure chamber 58 through the first negative pressure path 60 and the throttle introduced into the second negative pressure chamber 59 through the second negative pressure path 62 in the normal operating state of the engine. The diaphragm 5 is determined by the intake negative pressure on the side of the valve 4 and the loads of the pressure spring 63 and balance spring 64.
The main nozzle 48 reciprocates in a straight line depending on the position of the main nozzle 48, and changes the effective area of the main nozzle 48 to change the fuel flow rate supplied to the engine. That is, when the throttle valve 4 is at the idle position or at a small opening, a high negative pressure is generated in the boat 62a of the second negative pressure path 62 that opens into the intake path 2, and since the venturi negative pressure is low, the diaphragm 56 moves largely toward the second negative pressure chamber 59, reducing the effective area of the main nozzle 48. When the throttle valve 4 opens wide, the difference between the venturi negative pressure and the intake negative pressure on the sides of the throttle valve 4 becomes small, and when the opening is greater than the opening, the venturi negative pressure becomes higher, so the diaphragm 56 closes in the first negative pressure chamber. 58 to increase the effective area of the main nozzle 48. By such movement of the diaphragm 56, the intake air amount and the fuel flow rate can be made basically proportional, and the air-fuel ratio can be kept constant.
本発明の装置が製造されたとき、燃料圧力調整器25、
主ノズル48、燃料流量調整器55、計量ニードル79
の寸法誤差、組立ての狂いによって主ノズル48からエ
ンジンに供給される燃料流量がエンジン要求流量と異な
る場合がある。このような場合、調整ねじ72を回して
針片73を前後へ動かし、第一分岐路71の有効面積を
変えて第二負圧室62に導入される空気量を変え、第二
負圧室69の負圧を規準値よりも高く或いは低くするこ
とによってダイヤフラム56の動きを修正し、燃料流量
をエンジン要求流量と一致させる。When the device of the invention is manufactured, the fuel pressure regulator 25;
Main nozzle 48, fuel flow regulator 55, metering needle 79
The fuel flow rate supplied to the engine from the main nozzle 48 may differ from the engine required flow rate due to dimensional errors or assembly errors. In such a case, turn the adjustment screw 72 to move the needle piece 73 back and forth to change the effective area of the first branch path 71 and change the amount of air introduced into the second negative pressure chamber 62. By making the negative pressure at 69 higher or lower than the standard value, the movement of diaphragm 56 is modified to match the fuel flow rate with the engine required flow rate.
また、ダイヤフラム56が絞り弁4のアイドル位置のと
きの高い負圧で第二負圧室59の方へ犬きく移動したと
き、計量ニードル79が主ノズル48に必要異常に深く
差込まれて燃料流量をエンジン要求流量よりも減少させ
ることがある。或いは絞り弁4が開いた位置から急激に
閉じて第二負圧室59の負圧が急激に高くなってダイヤ
フラム56がオーバストロークし計量ニードル79を主
ノズル48に衝突させて破損するという心配がある。そ
のために、ねじ97を回してストッパ98を前後に移動
させ、アイドル時に適正流量の燃料を供給する位置、或
いは主ノズル48に衝突する少し手前の位置で計量ニー
ドル79の先端がストッパ98に衝ってそれ以上は差込
まれないように調整する。Furthermore, when the diaphragm 56 moves sharply toward the second negative pressure chamber 59 due to the high negative pressure when the throttle valve 4 is in the idle position, the metering needle 79 is inserted abnormally deeply into the main nozzle 48 and the fuel is The flow rate may be reduced below the engine required flow rate. Alternatively, there is a fear that the throttle valve 4 may suddenly close from the open position and the negative pressure in the second negative pressure chamber 59 will suddenly increase, causing the diaphragm 56 to overstroke and cause the metering needle 79 to collide with the main nozzle 48, causing damage. be. To do this, turn the screw 97 to move the stopper 98 back and forth, so that the tip of the metering needle 79 hits the stopper 98 at a position where a proper flow of fuel is supplied at idle, or at a position slightly before hitting the main nozzle 48. Adjust so that no more can be inserted.
次に、エンジンが始動するときの動作を説明する。Next, the operation when the engine starts will be explained.
小形車両、産業機械、発電機などを駆動する比較的小排
気量のエンジンはガバナをもっており、吸入空気量を制
御する絞り弁はエンジンが停止しているとき半開または
全開とされている。Relatively small displacement engines that drive small vehicles, industrial machinery, generators, etc. have governors, and the throttle valves that control the amount of intake air are half open or fully open when the engine is stopped.
エンジンは絞り弁を開いたまよ始動し急激に高速回転す
るようになるが、成る回転速度に達するとガバナが働い
て絞り弁をアイドル位置まで閉じさせ、その後は運転者
の操作によって絞り弁を所要開度とするものである。The engine starts with the throttle valve open and rapidly begins to rotate at high speed, but when it reaches that speed, the governor works to close the throttle valve to the idle position, and then the driver operates the throttle valve to open it as required. It is something that should be taken as a degree.
このため、エンジンがクランキングを行なっているとき
ベンチュリ負圧、絞り弁4の側方の吸気負圧、絞り弁4
の下流側の吸気負圧はいずれも低い、従って、負圧通路
96によって絞り弁4の下流側と接続されている負圧室
93に導入される負圧は低く、始動ばね94がダイヤフ
ラム92を大気室90の方へ移動させてロッド89を押
し、弁体84を第一の弁座82に押付けて第一負圧路6
0を閉じ補助負圧路61を開いている。For this reason, when the engine is cranking, the venturi negative pressure, the intake negative pressure on the side of the throttle valve 4, the throttle valve 4
The intake negative pressure on the downstream side of the throttle valve 4 is low. Therefore, the negative pressure introduced into the negative pressure chamber 93 connected to the downstream side of the throttle valve 4 by the negative pressure passage 96 is low, and the starting spring 94 causes the diaphragm 92 to Move it toward the atmospheric chamber 90 and push the rod 89, press the valve body 84 against the first valve seat 82, and open the first negative pressure path 6.
0 is closed and the auxiliary negative pressure path 61 is opened.
エンジンのクランクケースに発生するパルス圧の平均値
は2サイクルエンジンおよび4サイクルエンジンのいず
れであってもマイナスであって、補助負圧路61から弁
室81.出口路86を経て第一負圧室58に負圧が導入
される。このため、ダイヤフラム56は第一負圧室58
の方へ少し移動して主ノズル48から供給される始動用
燃料を増加させることができる。エンジンが完爆すると
吸気負圧はクランキング時に比べて高くなるので負圧室
93に導入される負圧が高くなってダイヤフラム92を
負圧室93の方へ移動させロッド89から離れる。この
ため、弁体84は戻しばね85のばね力で第一の弁座8
2から離れ第二の弁座83に押付けられ、第一負圧路6
0を第一負圧室58に連通させる。The average value of the pulse pressure generated in the engine crankcase is negative regardless of whether it is a 2-cycle engine or a 4-cycle engine, and is negative from the auxiliary negative pressure path 61 to the valve chamber 81. Negative pressure is introduced into the first negative pressure chamber 58 via the outlet passage 86 . Therefore, the diaphragm 56 is connected to the first negative pressure chamber 58.
The starting fuel supplied from the main nozzle 48 can be increased by moving a little towards the main nozzle 48. When the engine completely explodes, the intake negative pressure becomes higher than during cranking, so the negative pressure introduced into the negative pressure chamber 93 becomes higher, causing the diaphragm 92 to move toward the negative pressure chamber 93 and away from the rod 89. Therefore, the valve body 84 is moved to the first valve seat 8 by the spring force of the return spring 85.
2 and is pressed against the second valve seat 83, and the first negative pressure path 6
0 is communicated with the first negative pressure chamber 58.
このように、エンジンの始動時に燃料流量を増加させる
ことは低い温度のときに有効であり、そのために補助負
圧路61に温度弁100が設けられている、この温度弁
100は片持ち式の板状のバイメタル101の自由端に
取付けた針状の弁体102を有しており、温度が低いと
き弁孔103を大きく開き温度が高いとき閉じる。従っ
て、温度が高いときにエンジンが始動すると、第一負圧
路60は負圧制御弁80によって閉鎖され補助負圧路6
1は温度弁+00によって閉鎖されて0するため第一負
圧室58は大気圧となっている。このため、ダイヤフラ
ム56は第二負圧室59の方へ移動して主ノズル48か
ら供給される燃料流量をエンジンが完爆するまで少量と
する。As described above, increasing the fuel flow rate when starting the engine is effective when the temperature is low, and for this purpose, the temperature valve 100 is provided in the auxiliary negative pressure path 61. This temperature valve 100 is of a cantilever type. It has a needle-shaped valve body 102 attached to the free end of a plate-shaped bimetal 101, and the valve hole 103 opens wide when the temperature is low and closes when the temperature is high. Therefore, when the engine is started when the temperature is high, the first negative pressure path 60 is closed by the negative pressure control valve 80 and the auxiliary negative pressure path 60 is closed.
1 is closed by the temperature valve +00 and becomes 0, so the first negative pressure chamber 58 is at atmospheric pressure. Therefore, the diaphragm 56 moves toward the second negative pressure chamber 59 and reduces the flow rate of fuel supplied from the main nozzle 48 until the engine completely explodes.
更に、エンジンのクランクケースに発生させるパルス圧
を第一負圧室58に導入するとき、パルス圧の平均値が
低いとダイヤフラム56を充分に吸引して燃料を増加さ
せることができない。Furthermore, when the pulse pressure generated in the engine crankcase is introduced into the first negative pressure chamber 58, if the average value of the pulse pressure is low, the diaphragm 56 cannot be sufficiently suctioned to increase the amount of fuel.
そのために補助負圧路6Iに一方向弁105が設けられ
ている。この一方向弁+05は第9図を参照して球状の
弁体106とばね107とを有しており、燃料ポンプ5
のパルス室11から送られてくるパルス圧の一定以上の
負圧成分が弁体106に作用したときばね107を圧縮
して弁孔108を開く、従って、エンジンのクランキン
グ時に第一負圧室58を高い負圧とすることができる。For this purpose, a one-way valve 105 is provided in the auxiliary negative pressure path 6I. This one-way valve +05 has a spherical valve body 106 and a spring 107, as shown in FIG.
When the negative pressure component of the pulse pressure sent from the pulse chamber 11 acts on the valve body 106, it compresses the spring 107 and opens the valve hole 108. Therefore, when the engine is cranked, the first negative pressure chamber 58 can be at a high negative pressure.
エンジンが完爆した後は、先に述べたように絞り弁4が
大きく開かれているので急激に回転速度が高くなり、次
にガバナが働いて絞り弁4をアイドル位置まで閉じさせ
る。このとき、第二負圧路62の吸気路2へ開口したボ
ート62aは絞り弁4の上流側から下流側に突然移行し
て第二負圧室59の圧力が急激に変化するのを防ぐため
、ボート62aは吸気路2の軸線方向へ向かって複数個
設けられている。また、ベンチュリ負圧は絞り弁4が閉
じるに従って低くなるので、第一負圧室58の圧力が急
激に変化する心配がある。そこで、第一補正通路65の
吸気路2へ開口したボート65aを吸気路2の軸線方向
へ向かって複数個設けた。これらのボート62a、65
aの配列によって絞り弁4がアイドル位置の近くで動い
たときの第一負圧室58と第二負圧室59の圧力の急激
な変化を避けることができ、ダイヤフラム56の動きを
安定化して燃料流量を急激に変化させたり計量ニードル
79をオーバストロークさせて燃料流量を大幅に狂わせ
たりしない。After the engine has completely exploded, the throttle valve 4 is wide open as described above, so the rotational speed increases rapidly, and then the governor operates to close the throttle valve 4 to the idle position. At this time, in order to prevent the boat 62a opened to the intake path 2 of the second negative pressure path 62 from suddenly shifting from the upstream side to the downstream side of the throttle valve 4 and the pressure in the second negative pressure chamber 59 to change suddenly. , a plurality of boats 62a are provided in the axial direction of the intake passage 2. Furthermore, since the venturi negative pressure decreases as the throttle valve 4 closes, there is a concern that the pressure in the first negative pressure chamber 58 may change rapidly. Therefore, a plurality of boats 65a opening into the intake passage 2 of the first correction passage 65 are provided in the axial direction of the intake passage 2. These boats 62a, 65
With the arrangement a, it is possible to avoid sudden changes in the pressures of the first negative pressure chamber 58 and the second negative pressure chamber 59 when the throttle valve 4 moves near the idle position, thereby stabilizing the movement of the diaphragm 56. Do not change the fuel flow rate suddenly or overstroke the metering needle 79 to cause a large deviation in the fuel flow rate.
第二負圧路62は特開平1−32031号公報に開示さ
れているように絞り弁4の下流側で吸気路2に開口させ
ることも可能である。この場合は。The second negative pressure path 62 can also be opened into the intake path 2 on the downstream side of the throttle valve 4, as disclosed in Japanese Patent Application Laid-Open No. 1-32031. in this case.
第二負圧室59の圧力の急激な変化を避けるため、絞り
69および補正通路70の針片73が有効に働<。In order to avoid sudden changes in the pressure in the second negative pressure chamber 59, the throttle 69 and the needle piece 73 of the correction passage 70 work effectively.
第4図に見られるように、第二負圧室59の最も低い位
置に第二負圧路62を接続し、高い位置に補正通路70
を接続すると、計量ニードル79を伝わって第二負圧室
59に入った燃料が空気と一結に第二負圧路62を通っ
て吸気路2に排出され、第二負圧室59にためられるこ
とがない、補正通路70の第一分岐路71の有効面積を
調整する針片73は、第二負圧室59に導入される空気
流量を制御して第二負圧室59の負圧を調整し、ダイヤ
フラム56の位置従って主ノズル48から供給される燃
料流量を適正とするように働く、第二分岐路74の温度
弁75は温度が低いときに弁孔78を大きく開いて第二
負圧室59に大量の空気を導入し、第二負圧室59の負
圧を低下させてダイヤフラム56を通常よりも第一負圧
室58の方へ移動させ、燃料流量を増加するように働く
。As seen in FIG. 4, the second negative pressure passage 62 is connected to the lowest position of the second negative pressure chamber 59, and the correction passage 70 is connected to the highest position.
When connected, the fuel that has passed through the metering needle 79 and entered the second negative pressure chamber 59 is discharged together with the air through the second negative pressure path 62 to the intake path 2, and is stored in the second negative pressure chamber 59. The needle piece 73 that adjusts the effective area of the first branch path 71 of the correction passage 70 that is not affected by the air flow controls the air flow rate introduced into the second negative pressure chamber 59 to reduce the negative pressure of the second negative pressure chamber 59. The temperature valve 75 of the second branch 74 opens the valve hole 78 wide when the temperature is low, and works to adjust the position of the diaphragm 56 and thus the fuel flow rate supplied from the main nozzle 48. A large amount of air is introduced into the negative pressure chamber 59, the negative pressure in the second negative pressure chamber 59 is lowered, and the diaphragm 56 is moved more toward the first negative pressure chamber 58 than usual, thereby increasing the fuel flow rate. work.
本発明の要旨は、第6図に示されているように調圧室3
6の高い所に燃料タンクに達する戻し通路50を開口さ
せたことである。The gist of the present invention is as shown in FIG.
The reason is that the return passage 50 that reaches the fuel tank is opened at a high point of No. 6.
この戻し通路50は燃料に含まれている気泡が調圧室3
6で分離したとき、またはエンジンが停止した後に高い
温度のため燃料が蒸気を発生したとき、これらの空気や
燃料蒸気を排出するものである。また、エンジン運転中
は燃料の一部が戻し通路50を通って燃料タンクに戻る
ように、燃料ポンプ5から調圧室36に送られる燃料流
量をエンジン要求量よりも多くするように設定しておく
ことにより、殊に燃料圧力調整器25の温度上昇を抑制
することができる0本実施例では、低温時に増量する燃
料やエンジンの高負荷時に要求される燃料の一部を必要
以上に戻し通路50に流れさせず、且つ空気や蒸気の排
出を妨げないように考慮した絞り51が戻し通路50の
入口部分に設けられている。This return passage 50 allows air bubbles contained in the fuel to pass through the pressure regulating chamber 3.
6, or when the fuel generates steam due to high temperature after the engine has stopped, these air and fuel vapors are discharged. Further, while the engine is operating, the fuel flow rate sent from the fuel pump 5 to the pressure regulating chamber 36 is set to be greater than the amount required by the engine so that a portion of the fuel returns to the fuel tank through the return passage 50. In this embodiment, a portion of the fuel that increases at low temperatures or that is required when the engine is under high load is returned to the return path more than necessary. A throttle 51 is provided at the entrance of the return passage 50 in order to prevent the flow through the return passage 50 and to prevent the discharge of air and steam from being obstructed.
第11図には燃料圧力調整器25の調圧室36から空気
や燃料蒸気を燃料タンクに排出するための別の実施例が
示されている。この実施例では、調圧室36の最も高い
所に開口しており図示しない燃料タンクに達する戻し通
路+50に温度弁+51が設けられている。この温度弁
151は片持ち式の板状のバイメタル152の自由端に
取付けた針状の弁体153を有しており、温度が低いと
き弁孔154を閉鎖するかまたは小さく開き、温度が高
いとき大きく開く、これによって温度が低いときに増量
する燃料の一部を必要以上に戻し通路150に流れさせ
ず、温度が高いときに燃料蒸気を自由に排出することが
できる。FIG. 11 shows another embodiment for discharging air and fuel vapor from the pressure regulating chamber 36 of the fuel pressure regulator 25 into the fuel tank. In this embodiment, a temperature valve +51 is provided in a return passage +50 that opens at the highest point of the pressure regulating chamber 36 and reaches a fuel tank (not shown). This temperature valve 151 has a needle-shaped valve body 153 attached to the free end of a cantilevered plate-shaped bimetal 152, and when the temperature is low, the valve hole 154 is closed or slightly opened, and when the temperature is high, the valve hole 154 is closed or slightly opened. By doing so, a portion of the fuel that increases when the temperature is low is not allowed to flow into the return passage 150 more than necessary, and fuel vapor can be freely discharged when the temperature is high.
[発明の効果]
本発明によると、燃料圧力調整器の燃料をほぼ一定の正
圧力を維持させて一時的に滞留させる調圧室の高所に戻
し通路を開口させたので、燃料から分Ntシた空気や燃
料蒸気を直ちに排出させ調圧室の燃料圧力を狂わせない
ものである。[Effects of the Invention] According to the present invention, since the return passage is opened at a high place in the pressure regulating chamber where the fuel of the fuel pressure regulator is maintained at a substantially constant positive pressure and temporarily retained, Nt is removed from the fuel. This is to immediately exhaust air and fuel vapor to prevent the fuel pressure in the pressure regulating chamber from going out of order.
また、戻し通路に絞りを設けるときは燃料の一部を必要
以上に逃してエンジン運転を不調にするという心配がな
く、また温度弁を設けるときは高温時に大量に発生する
燃料蒸気を自由に排出し、燃料圧力調整器の正常な機能
を損わせないものである。In addition, when a throttle is installed in the return passage, there is no need to worry about unnecessarily escaping a portion of the fuel and causing engine malfunction, and when a temperature valve is installed, the fuel vapor that is generated in large quantities at high temperatures can be freely discharged. However, it shall not impair the normal functioning of the fuel pressure regulator.
第1図は本発明の一実施例を示す平面図、第2図は一部
切載した正面図、第3図は第1図のA−A線に沿う拡大
断面図、第4図は第1図のB −B線に沿う拡大断面図
、第5図は第2図のC−G線に沿う拡大断面図、第6図
は第2図のD−D線に沿う拡大断面図、第7図は第2図
のE−E線に沿う拡大断面部分図、第8図は第1図のF
−F線に沿う拡大断面部分図、第9図は第1図のG−G
線に沿う拡大断面部分図、第1O図は全体の部品と通路
との関係を説明する図、第11図は燃料圧力調整器の戻
し通路の異なる実施例を示す断面図である。Fig. 1 is a plan view showing one embodiment of the present invention, Fig. 2 is a partially cutaway front view, Fig. 3 is an enlarged sectional view taken along the line A-A in Fig. 1, and Fig. 4 is a 1, FIG. 5 is an enlarged sectional view taken along line C-G in FIG. 2, FIG. 6 is an enlarged sectional view taken along line D-D in FIG. Figure 7 is an enlarged partial cross-sectional view taken along line E-E in Figure 2, and Figure 8 is F in Figure 1.
- An enlarged partial cross-sectional view taken along line F, Figure 9 is GG in Figure 1.
FIG. 1O is a diagram illustrating the relationship between the overall parts and the passage, and FIG. 11 is a sectional view showing a different embodiment of the return passage of the fuel pressure regulator.
Claims (1)
記吸気路に開口し計量ニードルにより有効面積が可変の
主ノズルと、燃料をほぼ一定の正圧力に調整して前記主
ノズルに送る燃料圧力調整器と、ベンチュリ負圧と絞り
弁の側方またはその下流側の吸気負圧との差圧力に応じ
て前記計量ニードルを動作させエンジン吸気量にほぼ対
応して前記主ノズルの有効面積を変化させる燃料流量調
整器とを具えたエンジンの燃料供給装置において; 前記燃料圧力調整器の燃料をほぼ一定の正圧力に維持さ
せる調圧室の高所に燃料タンクに達する戻し通路が開口
しており、燃料流量を制限する絞りが前記戻し通路に設
けられていることを特徴とする燃料供給装置。 2、請求項1記載のエンジンの燃料供給装置における絞
りに代えて、温度が低いとき閉じるかまたは小さい開度
とされ温度が高いとき大きく開く温度弁が戻し通路に設
けられていることを特徴とする燃料供給装置。[Scope of Claims] 1. An intake passage having a fixed venturi and a throttle valve, a main nozzle that opens into the intake passage and whose effective area is variable with a metering needle, and a main nozzle that adjusts fuel to a substantially constant positive pressure. A fuel pressure regulator that sends fuel to the nozzle operates the metering needle according to the differential pressure between the venturi negative pressure and the intake negative pressure on the side of the throttle valve or downstream thereof, and controls the main nozzle in accordance with the engine intake air amount. a fuel flow regulator for varying the effective area of the fuel pressure regulator; a return passage reaching a fuel tank at a high point in the pressure regulating chamber for maintaining the fuel in the fuel pressure regulator at a substantially constant positive pressure; A fuel supply device characterized in that the return passage is open and a throttle for restricting the fuel flow rate is provided in the return passage. 2. In place of the throttle in the engine fuel supply system according to claim 1, a temperature valve is provided in the return passage, which closes or has a small opening when the temperature is low and opens wide when the temperature is high. fuel supply device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28257989A JPH03145565A (en) | 1989-10-30 | 1989-10-30 | Fuel feeding device for engine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28257989A JPH03145565A (en) | 1989-10-30 | 1989-10-30 | Fuel feeding device for engine |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH03145565A true JPH03145565A (en) | 1991-06-20 |
Family
ID=17654331
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP28257989A Pending JPH03145565A (en) | 1989-10-30 | 1989-10-30 | Fuel feeding device for engine |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH03145565A (en) |
-
1989
- 1989-10-30 JP JP28257989A patent/JPH03145565A/en active Pending
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