JPH0560036A - High voltage current type fuel injection ignition device - Google Patents

Abstract

PURPOSE:To accelerate atomization of fuel by providing a fuel injection nozzle of which forward end part is electrically insulated from a main body, and applying a pulse-shape or impulse-shape high voltage of at least several throusand to several ten-throusand volts to the nozzle tip electrode. CONSTITUTION:For a fuel injection device in which high pressure fuel is supplied from an injection pump 3 through an injection pipe 4, a tip part of a fuel injection nozzle 7 where a needle valve is fitted in is electrically insulated from a main body so that a high voltage can be applied from a high voltage controller 1 to the injection nozzle 7. A pulse-shape or impulse-shape high voltage of several throusand to several ten-throusand is applied to the nozzle tip electrode when fuel is injected for electrifying the fuel so that atomization of the fuel can be accelerated. A corona discharge electrode may be provided at the fuel injecting nozzle tip part to electrify and gasify the fuel so that ignition of the fuel can be performed simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip electrode of an injection nozzle whose tip is electrically insulated from the main body in, for example, an electronically controlled gasoline injection device, an electronically controlled diesel injection device, a fuel injection device for a gas turbine and the like. Atomization of fuel by applying pulsed or impulse high voltage synchronized with injection, or by providing a corona discharge electrode in front of the injection nozzle and passing fuel through corona discharge synchronized with injection of fuel The present invention relates to a fuel injection device that accelerates fuel consumption and improves fuel efficiency. More specifically, in a gasoline engine of a type that directly injects fuel into a cylinder, a corona discharge electrode is provided on the entire surface of the injection nozzle to synchronize with fuel injection. When passing the fuel through the generated corona discharge, give sufficient energy to ignite the atomized fuel by using a positive corona discharge that has a relatively high ignitability. Things by, but relates to a fuel injection ignition system of the type which simultaneously perform the ignition of the atomized fuel.

[0002]

2. Description of the Related Art Fuel injectors have made remarkable progress in recent years, and in internal combustion engines, especially gasoline engines, electronically controlled fuel injectors have recently become widespread, contributing to an improvement in fuel consumption rate. ..

However, regarding fine atomization of fuel, which is one of the factors of fuel economy, it depends largely on the injection mode of the fuel and the shape of the nozzle of the injection valve, and in particular, the fuel is directly injected into the combustion chamber. In a diesel engine or a gasoline engine that is injected with, the performance gradually deteriorates due to the adhesion and consumption of carbon during incomplete combustion, which is one of the factors that hinder optimal combustion.

[0004]

The problem to be solved is that even if the performance of the injection nozzle of the fuel injection device is deteriorated or the temperature is low, the fuel can be atomized to a certain degree, and the fuel atomization is more economical. It is an object of the present invention to provide a fuel injection device or a fuel injection ignition device capable of igniting fuel at various air-fuel ratios.

[0005]

The first invention of the present application uses a fuel injection nozzle in which a nozzle holder, a needle valve, and a part of the nozzle are made of an insulator such as ceramics, and the tip of the nozzle is an electrode. The atomization of the fuel is promoted by applying a pulsed or impulse-shaped high voltage synchronized with the injection of the fuel to the tip electrode of the nozzle. Further, since the high voltage control system applies a high voltage in time with fuel injection, a pulse or impulse high voltage is generated by a signal from the fuel injection pump side or a displacement signal of the needle valve of the injection nozzle. .. The polarity of the applied voltage is normally applied negative, but an alternating voltage or positive can be applied depending on the size and mechanism of ethidine. The tip electrode of the injection nozzle, the casing, the engine body, etc. are electrically insulated, and even when viewed from the fuel passage surface, even if the fuel used is conductive, Even if a pulsed or impulse-like high voltage is applied to the tip electrode by using an insulating material or the like up to the injection pump or by designing a large inductance for the fuel injection pipe side viewed from the tip electrode,
The effect is negligible. In addition, the high voltage control system has a built-in alarm function, current limiting function, automatic stop function, etc. if insulation failure occurs in the power supply circuit including the tip electrode for some reason.

In the high voltage flow type fuel injection ignition device according to the second invention of the present application, the injection nozzle is formed at an appropriate position on the front surface of the injection nozzle and the front surface of the injection nozzle made of an insulating material such as ceramics. Pulsed or impulse-shaped, electrically insulated, composed of at least a pair of discharge electrodes mounted so that the atomized fuel passes through its discharge surface and synchronized with the injection of fuel to the discharge electrodes Is applied to generate a corona discharge between the discharge electrodes and accelerate atomization or gasification of fuel. The basic principle of discharge timing is the same as that of the first aspect of the invention described above, but depending on the polarity of corona discharge, the discharge power, the shape and position of the electrodes, and the quantity, for example, in the case of a gasoline engine, etc., this discharge electrode allows the spark plug to operate. Atomized fuel can be ignited in the same manner as fuel is ignited. Therefore, in this case, the function of the spark plug can also be provided. Further, if the high voltage flow type fuel injection ignition device is used to directly inject fuel into the cylinder of a gasoline engine, the air-fuel ratio can be improved. In other words, not as a static ideal air-fuel ratio, but as a change in the dynamic partial air-fuel mixture ratio as a function of time, in which the spray produced by fuel injection moves in a very short time in a part of the cylinder space. In the process of atomizing and diffusing the fuel, it is possible to save fuel as a whole by performing discharge ignition at a position close to the ideal air-fuel ratio.

[0007]

In the present invention, when the fuel is injected by the fuel injection device, the injection nozzle tip electrode is pulsed or impulse-shaped,
Normally, by applying a negative high voltage, the surface tension of the fuel to be sprayed can be apparently changed from near zero to negative, so in addition to the atomization action on the shape of the injection port of the injection nozzle, Furthermore, it has the effect of promoting atomization, and can maintain the fine atomization function of the injection nozzle for a long time. Further, since a pulsed or impulse-shaped voltage is applied, the influence of the high voltage on other parts is extremely small. In addition, the fineness of the spray naturally leads to improved fuel efficiency and purification of exhaust gas. In the second invention, since the atomization of the fuel to be sprayed is promoted by using the corona discharge current to promote the atomization of the sprayed fuel, it is a method that consumes a little more electric power than the first invention and also during spraying. Arc discharge tends to be a little unstable, but it not only charges the spray, but also has the effect of simultaneously providing thermal energy by the spark. As a result, when gasoline is used, it can be used in the same way as a spark plug of a gasoline vehicle. It is also possible to have the same function as a glow plug when starting a diesel vehicle.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of a high-voltage fuel injection device according to the first aspect of the present invention. 1 is a high-voltage control device, 2 is a signal line for synchronizing with an injection pump, 3 is an injection pump, and 4 is an injection pump. The injection pipe, 5 is a high voltage cable connecting the high voltage controller and the injection nozzle,
6 is an insulating nozzle holder, 7 is an injection nozzle, 8 is a needle valve, 9 is a nozzle spring, and 10 is an adjusting screw.

2 and 3 are cross-sectional views of the injection nozzle portion of a corona discharge type high voltage flow type fuel injection ignition device.
Reference numeral 11 is a nozzle holder, 12 is a nozzle, 13 is a needle valve, 14 is a nozzle spring, 15 is an adjusting screw, 16 is a corona electrode, 17 is a high voltage line for corona discharge, 18 is an injection port, and 19 is a corona electrode. Usually, one of the corona discharge electrodes is grounded to the case and the car body, and the other is wired as a high voltage.

[0010]

In the present invention, since a high voltage is applied to the injection nozzle of the fuel injection device, the atomization is more uniformly and finely atomized, so that the fuel efficiency is improved. In addition, it is possible to compensate to some extent for the performance deterioration of the injection nozzle due to long-term use by promoting high-voltage atomization.

Further, in the second invention, since atomization of the fuel atomized by high-voltage discharge is promoted, thermal energy can be applied to the jet stream at the same time when the atomized fuel is charged. In addition to the invention, a gasoline engine can also have an ignition function. By using a fuel injection device that also has these functions,
For example, in a gasoline engine, it is possible to burn with a more dilute mixture, and smooth operation without knocking is performed at low speeds. Also in a diesel engine, the sprayed fuel can be heated by the discharge of the electrodes, so that it can be expected to function as a glow plug. Therefore, by using the high voltage flow type fuel injection ignition device of the present invention, it becomes possible to construct an engine or the like having low fuel consumption and good driving performance.

[0012]

[Brief description of drawings]

FIG. 1 is a schematic diagram of a high-voltage fuel injection device.

FIG. 2 is a sectional view of an injection nozzle of a discharge type high voltage flow type fuel injection ignition device.

FIG. 3 is a view of the injection nozzle of FIG. 2 seen from the nozzle mouth direction.

[Explanation of symbols]

 1 High Voltage Controller 2 Synchronous Signal Line 3 Injection Pump 4 Injection Pipe 5 High Voltage Cable 6 Insulated Nozzle Holder 7 Injection Nozzle 8 Needle Valve 9 Nozzle Spring 10 Adjustment Screw 11 Nozzle Holder 12 Nozzle 13 Needle Valve 14 Nozzle Spring 15 Adjustment screw 16 Corona electrode 17 High-voltage line 18 Injection port 19 Corona electrode

Claims (3)

[Claims] 1. A fuel injection device having a fuel injection nozzle in which a tip portion of the fuel injection nozzle is electrically insulated from a main body, and a pulsed or impulse-shaped high voltage of at least several thousands to tens of thousands of volts at the time of fuel injection. Is applied to a nozzle tip electrode to charge the fuel and accelerate atomization of the fuel. 2. A fuel injection device having a corona discharge electrode at the tip of a fuel injection nozzle, at the time of fuel injection, corona discharge is made from a corona discharge electrode at the tip of the injection nozzle, and a jet flow is passed through the corona discharge to charge the fuel. A fuel injection device characterized by being gasified. 3. A fuel injection device having a corona discharge electrode at the tip of a fuel injection nozzle, wherein a corona discharge electrode at the tip of the injection nozzle causes a corona discharge having a strength capable of igniting atomized fuel during fuel injection. , A fuel injection and ignition device characterized by simultaneously promoting the gasification of fuel and igniting the fuel.