JPS61167163A - Fuel injector - Google Patents

Abstract

PURPOSE:To sufficiently atomize fuel even in the low-speed operation range by arranging, inside an intake system, an injection valve having a piezoelectric element at the basic edge of a plunger arranged and by arranging an ionization electrode surrounding the injection outlet of the injection valve. CONSTITUTION:A fuel injection valve 10 is installed onto the upstream side of a throttle valve 2, positioned on the center line of a suction pipe. A valve body 22 for opening and closing an injection port 19 is fixed onto a valve rod 21 which extends forward at the top edge of a plunger 20. A piezoelectric element 23 is fitted between the bottom surface of a plunger chamber 17 and the basic edge surface of the plunger 20. Said piezoelectric element 23 vibrates, sharply reacting with the applied voltage, and correctly vibrates, even with the markedly high frequency. The fuel jetted-out in mist form from the injector 10 is electrified by an ionization electrode 25, and a portion of the ionized fuel is attracted to a deflecting electrode 26 and introduced into a fuel recovering device 27. Thus, fuel can be sufficiently atomized even in the low- speed operation range.

Description

【発明の詳細な説明】 本発明は主に自動重工／ジンに燃料を供給するための燃
料噴射装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a fuel injection device for fueling automatic heavy equipment/engines.

従来技術とその問題点 エンジンの吸気系に噴射弁から燃料を噴射するにあたっ
て、吸気マニホルドにエンジンのシリンダ毎に噴射弁を
設けるか、または吸気系の絞り弁上流側に噴射弁を設け
、エンジンの運転状態に応じて電子式の制御ユニットか
ら発せられる駆動信号パルスによって噴射弁を開閉し燃
料を噴射させることは周知である。Prior art and its problems When injecting fuel from an injection valve into the intake system of an engine, an injection valve is provided for each cylinder of the engine in the intake manifold, or an injection valve is provided upstream of the throttle valve in the intake system. It is well known that fuel is injected by opening and closing an injection valve using drive signal pulses issued from an electronic control unit depending on operating conditions.

噴射弁は電磁力で駆動され、一般に第３図に示すように
先端に噴口４１を有する弁本体４２に電磁コイル４３と
プランジャ４４とを内蔵させ。The injection valve is driven by electromagnetic force, and generally has an electromagnetic coil 43 and a plunger 44 built into a valve body 42 having a nozzle 41 at its tip, as shown in FIG.

電磁コイル４３に駆動信号パルスを送り励磁と消磁とを
繰返すことによってプランジャ４４を往復動させ、この
プランジャ４４の先端に設けた弁体４５によって噴口４
１ヲ開閉するようになつている。By sending a drive signal pulse to the electromagnetic coil 43 and repeating excitation and demagnetization, the plunger 44 is reciprocated, and the valve body 45 provided at the tip of the plunger 44 closes the nozzle 4.
1. It is designed to open and close.

このような電磁駆動の噴射弁は、第一に形状的に噴口４
１を有する先端側に比べ電磁コイル３３を包んだ基端側
かかなり大径であり、従って絞り弁上流側に設置する方
式の燃料噴射装置においては、吸気系の通路有効面積が
著しく狭くなるのでその周囲を拡げなげればならないと
いう問題がある。This type of electromagnetically driven injection valve has the following characteristics:
1, the diameter of the proximal end that surrounds the electromagnetic coil 33 is considerably larger than that of the distal end, and therefore, in a fuel injection device installed upstream of the throttle valve, the effective area of the passage in the intake system becomes significantly narrower. The problem is that the area around it needs to be expanded.

第二に機能的に可動部である電磁コイル４３の動作に不
満足な点があり、エンジンが高速回転したとき応答性が
遅いために充分な制御ができず、また低速回転域の燃料
消費量が少ない場合は動作が不安定になるばかりか噴射
された燃料の微粒化が不充分で燃焼状態を悪化するとい
う問題がある。Secondly, there are some unsatisfactory points in the operation of the electromagnetic coil 43, which is a functionally movable part, and when the engine rotates at high speed, the response is slow, making it impossible to control it sufficiently, and the fuel consumption in the low speed range is low. If the amount is too small, there is a problem that not only the operation becomes unstable but also the atomization of the injected fuel is insufficient and the combustion condition deteriorates.

管３．吸気マニホルド４は吸気系５を構成し本発明は、
噴口を開閉する弁体を先端に有し弁本体内を往復動する
プランジャの基端に圧電素子を配置した噴射弁が吸気系
の内部に設置さね、この噴射弁の噴口の出口を囲んでイ
オン化電極が設置されているとともに、帯電した燃料噴
射流な囲んで偏向電極および燃料回収器が設置されてい
る構成としたことによって前記問題点を解決するための
手段とした。Tube 3. The intake manifold 4 constitutes an intake system 5, and the present invention includes:
An injection valve is installed inside the intake system, and has a valve body at its tip that opens and closes the nozzle, and a piezoelectric element at the base end of a plunger that reciprocates within the valve body. A means for solving the above-mentioned problems is provided by providing a configuration in which an ionizing electrode is installed, and a deflection electrode and a fuel recovery device are installed surrounding the charged fuel jet stream.

本発明の実施例を図面に基いて説明すると。An embodiment of the present invention will be described based on the drawings.

エアクリーナ１を通った空気は絞り弁２を有する吸気ｇ
３を経て吸気マニホルド４からエンジン６に吸込まれ、
排出ガスは排気マニホルド７から触媒８を経て排気管９
より大気中に放出されるもので、エアクリーナ１．吸気
られた圧電素子２３を装入して構成され、プラている。The air that has passed through the air cleaner 1 is drawn into an intake g with a throttle valve 2.
3 and is sucked into the engine 6 from the intake manifold 4,
Exhaust gas flows from the exhaust manifold 7 through the catalyst 8 to the exhaust pipe 9.
Air cleaner 1. It is constructed by inserting an inhaled piezoelectric element 23, and is made of plastic.

噴射弁１０は吸気管３の中心線上に位置させて絞り弁２
の上流側に設置され、燃料夕／り１１の燃料は燃料ポン
プ１２を有する燃料管１３を通って噴射弁１０の弁室１
８に送られ噴口１９から円錐状に拡げられて噴射させら
れるものであり、弁室１８の燃料は戻し管１４の圧力調
整器１５によって所定圧力に調整されるのである。The injection valve 10 is located on the center line of the intake pipe 3 and the throttle valve 2
The fuel in the fuel tank 11 passes through a fuel pipe 13 having a fuel pump 12 and enters the valve chamber 1 of the injection valve 10.
The fuel in the valve chamber 18 is regulated to a predetermined pressure by the pressure regulator 15 in the return pipe 14.

噴射弁１０は、弁本体１６にプランジャ室１７と弁室１
８とを設けるとともに弁室１８の先端に噴口１９ヲ設け
、プランジャ室１７に往復動可能に装入したプランジャ
２０の先端前方へ延びる弁棒２１に前記噴口１９を開閉
する弁体２２を固着し。The injection valve 10 has a plunger chamber 17 and a valve chamber 1 in a valve body 16.
8 and a nozzle 19 is provided at the tip of the valve chamber 18, and a valve body 22 for opening and closing the nozzle 19 is fixed to a valve rod 21 extending forward at the tip of a plunger 20 inserted into the plunger chamber 17 so as to be reciprocally movable. .

更にプランジャ室１７の底面とプランジャ２００基端面
との間にプランジャ２０とほぼ同径に作ンジャ室１７の
先端部側面に接続開口した二つの燃料通路２４ｍ、２４
ｂに前記燃料管１３および戻し管１４がそれぞれ接続し
ている。圧電素子２３は電圧を印加すると機械的歪み即
ち振動を発生する物質で作られ、チタン酸バリウム、チ
タン酸鉛、ジルコン酸鉛或いは三成分系のセラミックス
、人工結晶、有機高分子物質など圧電現象を示す物質が
使用可能であるが、圧電率が大きく且つ温度変化の影響
を受けにくいものが好ましい。また、圧電素子２３は二
個以上を重ねて使用することもあり、更にプランジャ室
１７とプランジャ２０とに固着すればこれらを互いに常
時接触させるばねが不要である。Furthermore, two fuel passages 24m and 24 are formed between the bottom surface of the plunger chamber 17 and the base end surface of the plunger 200 and have a diameter approximately the same as that of the plunger 20, and are connected and opened on the side surface of the tip end of the plunger chamber 17.
The fuel pipe 13 and the return pipe 14 are respectively connected to b. The piezoelectric element 23 is made of a material that generates mechanical strain, that is, vibration when a voltage is applied, and is made of a material that exhibits piezoelectric phenomena, such as barium titanate, lead titanate, lead zirconate, three-component ceramics, artificial crystals, and organic polymer materials. Although the materials shown below can be used, it is preferable to use a material that has a high piezoelectric constant and is not easily affected by temperature changes. Furthermore, two or more piezoelectric elements 23 may be used in stacks, and if they are fixed to the plunger chamber 17 and the plunger 20, there is no need for a spring to keep them in constant contact with each other.

前記噴射弁１０の噴口１９の出口を囲んでイオ／化電極
２５が設置され、更にその少し下流側において吸気管３
の内側周面に偏向電極２６および樋状の燃料回収器２７
が設置され、この燃料回収器２７はポンプ２８を有する
回収管２９によって燃料タンク１１に接続されている。An ionization electrode 25 is installed surrounding the outlet of the nozzle 19 of the injection valve 10, and further downstream of the ionization electrode 25, the intake pipe 3
A deflection electrode 26 and a gutter-shaped fuel recovery device 27 are provided on the inner peripheral surface of the
is installed, and this fuel recovery device 27 is connected to the fuel tank 11 by a recovery pipe 29 having a pump 28.

電子式の制御ユニッ）３０には吸気圧力センサ３１．エ
ンジン回転速度センサ３２．排出ガス組成分センサ３３
からの電気信号が連続的に人力され、データ処理して全
運転域に亘り燃料ポ／プ１２．噴射弁１０に適切な駆動
信号を送るとともに、イオン化電極２５．偏向電極２６
に適切な電圧または周波数の電流を印加するもので、制
御二二ツ）３０には前記以外に吸入空気温度、エンジン
温度、絞り非温度などエンジンの運転状態を検出するセ
ンナからの電気信号が必要に応じて人力される。The electronic control unit) 30 includes an intake pressure sensor 31. Engine rotation speed sensor 32. Exhaust gas composition sensor 33
The electrical signals from the fuel pump 12. In addition to sending appropriate drive signals to the injector 10, the ionization electrode 25. Deflection electrode 26
In addition to the above, electrical signals from the sensor are required to detect engine operating conditions such as intake air temperature, engine temperature, and throttle temperature. Manpower will be provided depending on the situation.

噴射弁１０の噴口１９から円錐状に拡がりながら霧状に
噴射された燃料はイオン化電極２５によって帯電し９次
でイオン化した燃料の一部はその噴射流を囲んで配置し
た偏向電極２６に吸引されて燃料回収器２７に入り、そ
れ以外の燃料がエンジン６に供給されるのである。ここ
で、燃料噴射量は噴射弁１０の圧電素子２３に加えられ
る駆動信号パルスのデユーティ比によって決定され、エ
ンジン供給量はイオン化電極２５および偏向電極２６に
印加される電圧または周波数によって制御される。The fuel injected in the form of a mist while expanding conically from the nozzle 19 of the injection valve 10 is charged by the ionization electrode 25, and a part of the 9-order ionized fuel is attracted to the deflection electrode 26 arranged around the injection stream. The remaining fuel enters the fuel recovery device 27 and is supplied to the engine 6. Here, the fuel injection amount is determined by the duty ratio of the drive signal pulse applied to the piezoelectric element 23 of the injection valve 10, and the engine supply amount is controlled by the voltage or frequency applied to the ionization electrode 25 and the deflection electrode 26.

本発明によると、噴射弁を圧電素子の振動によって駆動
するようにしたので、従来の電磁力駆動のものに比べて
著しく小形となり吸気系に通路有効面積を著しく狭くす
ることなくそのまま設置できるものであり、且つ圧電素
子は印加電圧に鋭敏に反応して振動するとともに著しく
高い振動数でも正確に振動するので、エンジンの全運転
域に亘ってすぐれた応答性、安定性をもって燃料を噴射
し、従って低速運転域でも燃料を充分に微粒化できるの
である。According to the present invention, since the injection valve is driven by the vibration of a piezoelectric element, it is significantly smaller than the conventional one driven by electromagnetic force, and can be installed as is in the intake system without significantly narrowing the effective passage area. In addition, the piezoelectric element vibrates in response to applied voltage and vibrates accurately even at extremely high frequencies, so fuel can be injected with excellent responsiveness and stability over the entire operating range of the engine. The fuel can be atomized sufficiently even in low-speed operating ranges.

また、噴射した燃料をイオン化し一部を偏向させて回収
するようにしたので、噴射弁のデユーティ比を大幅に変
えることなく最も安定した作動範囲内で開閉を行なわせ
、エンジン運転状態に応じて燃料回収量を変えエンジン
供給量を適正に制御できるものである。In addition, the injected fuel is ionized and a portion is deflected and recovered, allowing the injector to open and close within the most stable operating range without significantly changing the duty ratio, allowing the valve to open and close according to engine operating conditions. It is possible to appropriately control the amount of fuel supplied to the engine by changing the amount of fuel recovered.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は不発明の実施例を示す配置図、第２図は噴射弁
の縦断面図、第３図は従来の噴射弁の縦断面図である。 ２・・・・・・絞り弁、５・・・・・・吸気系、６・・
・・・・エンジン、１０・・・・・・噴射弁、１６・・
・・・・弁本体、１９・・曲・噴口、２０・・・・・・
グラ／ジャ、２２・・・・・弁体、２３・・・・・・圧
電素子、２５・・・・・・イオン化電極、２６・・・・
・・偏向電極、２７・・・・・・燃料回収器、３０・・
・・・・制御ユニット。 第２図　　　　第３図 １０−、−ｎｌ　ｇ弁　　　　　　２ｏ・・−プランジ
゛ヤ／６．−４ｆ本体　２２・−・弁体 ／９．、、、貴　　　０　　　　　　　　２３−・圧電
素手手続補正書（方式） ％式％］ ２　発明の名称 燃料噴射装置 ３　補正をする者 事件との関係　特許出願人 住所　　　東京部品用凶兆品用５丁目１番１２号氏名（
名称）　株式会社　日本気化器製作所４　代理人（〒１
０４） 住所　東京都中央区京橋３丁目５番３号（竹河岸ビル）
５　補正命令の日付　　昭和６０年　４月３０日発送６
　補正の対象 図面FIG. 1 is a layout diagram showing an embodiment of the invention, FIG. 2 is a longitudinal sectional view of an injection valve, and FIG. 3 is a longitudinal sectional view of a conventional injection valve. 2... Throttle valve, 5... Intake system, 6...
...Engine, 10...Injection valve, 16...
...Valve body, 19...Curve/nozzle, 20...
Gra/ja, 22... Valve body, 23... Piezoelectric element, 25... Ionization electrode, 26...
...Deflection electrode, 27...Fuel recovery device, 30...
····Controller unit. Fig. 2 Fig. 3 10-, -nl g valve 2o...-plunger/6. -4f main body 22... Valve body/9. ,,,you 0 23- Piezoelectric bare hand procedure amendment (method) % formula %] 2 Name of the invention Fuel injection device 3 Relationship to the case of the person making the amendment Patent applicant address 5-1, Tokyo Parts Co., Ltd. Name 12 (
Name) Nippon Kakariki Seisakusho Co., Ltd. 4 Agent (〒1
04) Address: 3-5-3 Kyobashi, Chuo-ku, Tokyo (Takegashi Building)
5 Date of amendment order Sent on April 30, 19856
Drawings subject to correction

Claims (1)

【特許請求の範囲】 噴口を開閉する弁体を先端に有し弁本体内 を往復動するプランジャの基端に圧電素子を配置した噴
射弁が吸気系の内部に設置され、この噴射弁の噴口の出
口を囲んでイオン化電極が設置されているとともに、帯
電した燃料噴射流を囲んで偏向電極および燃料回収器が
設置されていることを特徴とする燃料噴射装置。[Scope of Claims] An injection valve is installed inside the intake system, and has a valve body at its tip that opens and closes the nozzle, and a piezoelectric element arranged at the base end of a plunger that reciprocates within the valve body. An ionizing electrode is installed surrounding an outlet of the fuel injection device, and a deflection electrode and a fuel recovery device are installed surrounding an electrically charged fuel injection stream.