KR20070063881A - An injector of engine in a car - Google Patents

Abstract

An injector of a vehicle engine is provided to reduce soot and exhaust gas and to improve output and fuel efficiency by finishing fuel injection at the state where an intake valve is shut, even when a large amount of fuel injection is required due to engine loads. An injector of a vehicle engine includes a needle(2) which is lifted by the magnetization of a coil assembly(1) to open an injection hole; and a stopper protruded from a nozzle body(N) so as to limit the elevating degree of the needle. The stopper is a piezo stopper(10) constituted by a piezo element(11). The piezo element is connected to an insert body(12) inserted into a mounting hole of the nozzle body, and protruded toward the inside of the nozzle body. The piezo element has a lower surface which is transformed when power is applied.

Description

An injector of engine in a car}

1 is a cutaway perspective view of a typical injector,

2 is a schematic configuration diagram of a conventional injector,

3 is a graph showing a relationship between fuel injection timing and injection time determined in an engine control unit;

4 is a configuration diagram of an injector according to the present invention;

5 is a graph showing the injection characteristics of the injector according to the present invention.

** Description of the symbols for the main parts of the drawings **

1: coil assembly, 2: needle,

10: piezo stopper, 11: piezo element part,

12: insert body, 13: wire,

20: engine control unit, N: nozzle body.

The present invention relates to an injector of an automobile engine, and more particularly, to an injector of an automobile engine capable of improving exhaust characteristics and performance characteristics under high load driving conditions by improving atomization and evaporation rate of fuel flowing into a cylinder.

The injector of the present invention is an injector which is operated by an engine control unit (ECU) and injects fuel supplied at a predetermined pressure into the intake pipe of the engine.

As shown in FIG. 1, the injector includes a coil assembly 1 that receives electric power and generates a magnetic force, a needle 2 that is pulled upward when the magnetic force is generated in the coil assembly 1, and the needle 2. It is configured to include a valve seat (3) that the lower end of the) abuts to block the injection hole (4).

Therefore, when power is applied to the coarse assembly 1, the needle 2 moves upward and the injection hole 4 is opened, so that fuel is injected into the intake pipe.

Also, as shown in FIG. 2, the conventional injector is provided with a stopper 5 which is installed with the end protruding from the nozzle body N to limit the lift amount (rising amount) of the needle 2. .

Therefore, the injection fuel amount of the conventional injector is determined as a function of the time that the needle 2 is lifted (time that the injection hole 4 is open).

On the other hand, Figure 3 shows the relationship between the fuel injection timing and the injection time determined in the engine control unit.

In general, the injection fuel amount is determined based on the intake air amount, and the fuel injection start and end points are determined based on the intake air amount.

As shown in (a), the fuel injection is finished before the intake valve is opened, and the fuel injected into the intake pipe is atomized and evaporated in the intake pipe, and then the intake valve is opened and introduced into the cylinder.

If, as in (b), the operating condition of the engine is increased in speed and the load is high, the engine control unit requires an increase in fuel quantity, and in order to satisfy this demand, the injector immediately after the intake of the previous cycle is completed. And even proceed through the suction cycle of the current cycle.

This is because the conventional injector lifts the needle 2 as described above by the stopper 5 so that the adjustment of the injection fuel amount is possible only by the injection time adjustment.

However, when the injection is carried out under the above conditions, a part of the injected fuel does not go through the atomization and evaporation process in the intake pipe and immediately flows into the cylinder, resulting in poor atomization and poor mixing with air. Because of this, there was a problem in that the combustion characteristics deteriorated (generated unburned emissions such as soot, soot).

Accordingly, the present invention has been made to solve the above problems, the adjustment of the needle lift to enable the adjustment of the fuel injection amount to be made by the needle lift control as well as the injection time, even before the intake process of the next cycle even a large amount of fuel It is an object of the present invention to provide an injector of an automobile engine that is capable of terminating the spraying process and thus undergoes sufficient atomization and evaporation process and improves mixing with air.

The present invention for achieving the above object,

In the injector of an automobile engine having a needle which is raised by magnetization of the coil assembly to open the injection hole, and a stopper which is installed in a state protruding from the nozzle body to limit the amount of lifting of the needle,

The stopper is characterized in that the piezo stopper consisting of a piezo element.

That is, the fuel injection amount can be adjusted by varying the lift limit position of the needle by using the deformation of the stopper.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

4 is a block diagram of an injector according to the present invention.

In the present invention, the stopper is changed in the injector having the same structure as before.

That is, the injector basically includes a coil assembly 1 which is supplied with power and magnetized, and a needle 2 which is opened and lowered by the coil assembly 1 to open and close. The piezo stopper 10 is provided as a stopper for limiting the lift.

The piezo stopper 10 is formed of a piezo element, and a piezo element (piezoelectric element) refers to an element in which deformation in proportion to the voltage occurs or a reverse reaction occurs when a voltage is applied.

In the piezo stopper 10, the piezoelectric element part 11 is exposed to the outside of the inner circumferential surface of the nozzle body N to serve as a stopper, and an insert body 12 connected to the piezoelectric element part 11 is connected to the nozzle body. It is inserted into and fixed to the mounting groove formed on the inner circumferential surface of (N), the piezo element portion 11 is connected to the engine control unit 20 via a wire 13 passing through the nozzle body (N) to control the current It is supposed to be authorized.

When it is necessary to increase the fuel injection amount, the engine control unit 20 applies a voltage to the piezoelectric element unit 11 to cause deformation of the element.

Naturally, the piezoelectric element part 11 is manufactured to cause deformation of the lower end part when a voltage is applied. That is, in Fig. 4 it is to be modified to a position higher than the basic position.

Hereinafter, the effect of the present invention will be described.

The engine control unit (ECU) 20 determines the stroke of each cylinder from the signals of the engine crank and the cam sensor, calculates the time between strokes, and comprehensively calculates the driver's acceleration intention transmitted from the driver's accelerator pedal operation signal. Judgment is made to determine the fuel injection amount.

The fuel injection amount is a fuel amount that is firstly corrected by adjusting the magnetization time of the coil assembly 1 to the basic fuel injection amount, and in the present invention, when it is necessary to inject a larger amount of fuel, the piezoelectric element 11 is deformed. The secondary injection amount correction is made to increase the injection amount by adjusting the time.

In actual operation, the engine control unit 20 performs the piezo stopper under normal operating conditions, i.e., when the injection end point does not affect the atomization and evaporation process of the injected fuel in the intake pipe (injection is performed with the intake valve closed). No current is applied to (10).

Accordingly, the lower surface of the piezoelectric element 11 is positioned at the basic position, so that fuel injection is performed under the same conditions as in the prior art. (The fuel amount is controlled only by the injection time.)

However, when the operating conditions of the piezo stopper 10 (injection is performed with the intake valve opened), the piezoelectric element 11 is deformed by supplying current to the piezo stopper 10.

Therefore, since the lower end surface of the piezoelectric element 11 rises from the basic position, that is, the needle lift increases, so that the injection flow rate per unit time increases.

Therefore, it is possible to inject the required injection amount before the intake stroke of the next cycle is started, that is, while the intake valve is closed.

5 shows the degree of injection increase with time before and after the time when the piezo stopper 10 is operated during fuel injection. As shown, it can be seen that a larger amount of fuel is injected after the piezo stopper 10 is operated.

Therefore, the atomization and evaporation of the fuel particles, and the mixture with the air is insufficient, the fuel is not supplied into the cylinder, it is possible to prevent the phenomenon that the combustion characteristics deteriorate.

As described above, according to the present invention, even when the amount of injection fuel required according to the engine load conditions is large, it is possible to stop the injection of fuel while the intake valve is always closed, so that atomization, evaporation rate and air and It is possible to improve the mixing characteristics of the exhaust characteristics (soot and harmful exhaust gas reduction) and performance characteristics (increased output, improved fuel economy) generated under high load operating conditions.

Claims (3)

An automobile engine having a needle 2 which is lifted by magnetization of the coil assembly 1 to open the injection hole, and a stopper which is installed in a state protruding from the nozzle body N to limit the amount of lift of the needle 2. In the injector of Injector of the vehicle engine, characterized in that the stopper is a piezo stopper (10) consisting of a piezo element (11). The piezoelectric element (11) is connected to an insert body (12) inserted into and fixed to a mounting hole of the nozzle body and protrudes to the inner side of the nozzle body. Injector of an automobile engine, characterized in that the moving deformation is configured to occur. 2. The piezoelectric element (11) according to claim 1, wherein the piezoelectric element (11) is connected to the engine control unit (20) via a wire (13) passing through the nozzle body, and the engine control unit (20) is the amount of fuel required only by adjusting the injection time. Injecting the piezoelectric element (11) to increase the needle lift when it cannot be finished before the start of the intake stroke of the next cycle.

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