JPS6312856A - Fuel injection valve driving device for internal combustion engine - Google Patents

Abstract

PURPOSE:To open a fuel injection valve quickly, by applying a preliminary voltage lower than a driving voltage of fuel injection valve across an electromagnetic coil of the fuel injection valve at least until the valve-open time thereby improving the rising of current flowing through the electromagnetic coil. CONSTITUTION:When an internal combustion engine is operated and a crank position is detected through a crank position detecting means 17, an advance pulse is outputted prior to an injection pulse while being synchronized with the open valve timing of an intake valve from an advance pulse generating means 30 on the basis of the outputs from an injection timing determining means 26 and an advance pulse generating timing determining means 29. A transistor Tr31 in an injection valve driving means 25 is turned on by said advance pulse so as to apply a preliminary voltage across an electromagnetic coil 23. Said preliminary voltage is set lower than the lowest voltage for driving a fuel injection valve 5 so as to avoid opening of said valve 5. When an injection pulse is outputted subsequently from an injection pulse generating means 27 subsequently, Tr32 is turned on so as to open the fuel injection valve 5 quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field 1) This invention relates to a fuel injection valve drive device that opens and closes a fuel injection valve that supplies fuel to an internal combustion engine.

(Prior Art) Some internal combustion engines are equipped with electromagnetic fuel injection valves. In this electromagnetic fuel injection valve, a voltage is applied to the electromagnetic coil in synchronization with the opening timing of the intake valve that supplies fuel to the internal combustion valve, and the fuel injection valve is held open by excitation of the electromagnetic coil. , is designed to inject fuel.

(Is it an invention or a problem to be sued?) By the way, there is a demand to further improve the I6 response of this fuel injector, and for this reason, is it possible to consider increasing the electromagnetic coil's stamping power? It is necessary to excite the electromagnetic coil while maintaining the open state of the fuel injection valve, which increases the heat generation of the electromagnetic coil. In particular, when the engine rotates at high speed, the fuel injection period becomes shorter as the engine speed increases, further accelerating heat generation in the electromagnetic coil.

Therefore, if the voltage applied to the electromagnetic coil is suppressed to a low level by sacrificing the responsiveness to some extent, the rise time of the current flowing through the magnetic coil becomes longer. As a result, the adjustment range of the fuel injection amount becomes narrower, and the effect on the fuel injection amount is particularly large when the engine rotates at high speed.

The present invention was made in view of the above, and an object of the present invention is to provide a fuel injection valve drive device for an internal combustion R injector that improves the responsiveness of the opening operation of a fuel Oa injection valve without causing heat generation in the electromagnetic coil. shall be.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an electromagnetic coil of a fuel injection valve that injects fuel provided in an internal combustion engine.
In a fuel injection valve drive device for an internal combustion engine, which applies a voltage in synchronization with the opening timing of an intake valve that supplies fuel to the internal combustion engine, and opens the fuel injection valve to inject fuel. The present invention is characterized in that a preliminary voltage lower than the driving voltage for driving the fuel injection valve is applied to the surface electric treadle coil from before the valve opens until at least when the valve opens.

(Function) This invention provides an electromagnetic coil of a fuel injection valve with a fuel F + injection force
Apply a preliminary pressure that is lower than the driving pressure.

With the application of this preliminary voltage, the driving voltage that drives the fuel injector is lowered, resulting in a stream flowing through the electromagnetic coil. Therefore, the responsiveness of the valve opening operation of the fuel pg injection valve is improved without increasing the dynamic voltage of the electromagnetic coil.

(Embodiment) An embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a fuel injection system for an internal combustion engine to which the present invention is applied.

The fuel stored in the fuel tank 1 is pumped by a fuel pump 2, filtered by a fuel filter 3, the pressure of the fuel is adjusted by a pressure regulator 4, and then sent to an electromagnetic fuel injection valve 5 provided in the intake system. Supplied. The fuel injection valve 5 is driven by a drive device 6 and injects fuel into an intake passage 7 of the internal combustion engine. The air cleaner 8 on the downstream side of the intake passage 7 is provided with an intake air amount detection means 9 and an intake air temperature detection means 10. A throttle valve 11 is also arranged in the intake passage 7 to adjust the amount of intake air supplied.
The opening degree of 1 is detected by the throttle position detection means 12.

A crank (1114) connected to the piston 13 of the internal combustion engine
is provided with a cam 15, an engine rotation speed detection means 16 detects the Rr'A rotation speed from the rotation of the cam 15, and a crank position detection means 17 detects the crank position from the position of the camshaft 18.

The combustion chamber 19 of the internal combustion engine 81 and the intake passage 7 are opened and closed by the intake 'F.
? 20, the combustion chamber 19 and the exhaust passage 21 are opened and closed by an exhaust valve 22, and the intake valve 20 and the exhaust valve 22 are opened and closed at predetermined timings, respectively.

The intake air amount pressure detection means 9 and the intake air temperature detection means 10
The detection signals of the throttle position detecting means 12, the crank position detecting means 17, and the engine speed detecting means 16 are manually inputted to the drive device 6, and the fuel inlet n injection valve 5 is synchronized with the opening timing of the suction aperture 20. , and the valve is opened for a predetermined time depending on the operating condition.

FIG. 2 is a block diagram of a drive device that drives the electromagnetic fuel injection valve.

Reference numeral 23 denotes an electromagnetic coil of the electromagnetic fuel injection valve 5, and the coil 23 is connected to a power source 24.A voltage is applied to the electromagnetic coil 23 by the injection valve driving means 25, and the electromagnetic coil 23 is connected to a power source 24. 23 actuates the fuel injection '11-5, and fuel is injected into the intake passage 7.

Based on the detection signal obtained by the crank position detection means 17,
The injection timing determining means 26 determines the generation timing of an injection pulse that is synchronized with the valve opening timing of the suction A ax 20. Based on this determination, the injection pulse generating means 27 generates a predetermined injection pulse as shown in FIG. 3(b). The injection pulse of the day can be obtained.

The pulse width of the injection pulse is set by the injection time determining means 28, and the pulse width is based on detection signals from the engine rotational speed detection means 16, the intake air amount detection means 9, the intake air temperature detection means 10, and the throttle position detection means 12. , determined according to the operating conditions of the internal combustion engine.

Further, the signal from the crank position detection means 17 is sent to the preliminary pulse generation timing determining stage 29, and the pre-pulse generation means 30 receives a signal from the pre-pulse generation timing determination means 29 and the injection timing determination means 26, which determines the timing of the injection pulse. Obtain a pre-pulse generated from the tl bait.

Note that this preliminary pulse is used in the 1n pulse generation timing state determining means 29 to obtain a corresponding injection pulse.
The determination may be made based on the crank position detection No. 18.

As mentioned above, this preliminary pulse rises from the bait for a predetermined time tl from the output timing of the injection pulse, and has a predetermined pulse width t2 that is output at least from the start of the injection pulse to the end. It is certain that this will be done.

These preliminary pulses and injection pulses are used by the injection valve driving means 2
The emitters of these transistors 31, 32 are grounded, and the collectors are respectively connected to the electromagnetic coil 23 of the fuel injection valve 5 via resistors VL33 and 34.

The transistor 31 is connected 4 times by inputting a preliminary pulse,
As a result, the preliminary voltage Vl, which is lowered by the resistor 33, is applied to the electromagnetic coil 23. This preliminary voltage (1) is set to a voltage that is smaller than the minimum drive voltage required to open the fuel injection valve 5, as shown in FIG. 3<C>.

Further, the transistor 32 is made conductive by the manual force of the injection pulse, and as a result, the driving voltage V2, which is voltage-dropped by the resistor 34, is applied to the electromagnetic coil 23, which causes the electromagnetic coil 23 to be electromotive, and the fuel injection valve 5 to be activated for a predetermined period of time. t3 Valve opens. The driving voltage V2 at this time opens the fuel injection valve 5,
Moreover, the voltage is set to a level necessary to keep the valve open.

Next, the operation of this embodiment will be explained.

The crank position detection means 17 detects the crank position by operating the internal combustion engine. Based on this detection signal, the injection timing determining means 26 and the pre-pulse generation timing determining means 29 determine the output timing of the pre-pulse which is synchronized with the opening timing of the intake valve 20 and which is easier to output than the injection pulse. Based on this determination, a preliminary pulse having a predetermined pulse width t2 shown in FIG. 3(a) is outputted a predetermined time t1 before the output of the injection pulse.

When this one pulse of vehicle weight is applied to the base of the transistor 31 of the injection valve driving means 25, conduction occurs and a preliminary voltage is applied to the electromagnetic coil 23 of the fuel injection valve 5. The preliminary voltage Vl at this time is the voltage drop of the resistor I3, and the fuel injection 1P5
The valve is not opened because it is set lower than the lowest possible driving voltage.

Next, after a predetermined time t1, the injection pulse generating means 27 outputs an injection pulse for obtaining a fuel injection time corresponding to the operating condition shown in FIG. 3 (bJ).

When this injection pulse is input to the base of the transistor 32, it becomes conductive. As a result, the drive voltage v2, which has been dropped by the resistor 34, is applied to the electromagnetic coil 23. At this time, the drive voltage v2 is the minimum necessary voltage to open the fuel injection valve 5 and maintain the valve open state, but a current is flowing through the electromagnetic coil 23 in advance. Therefore, it is possible to shorten the time it takes to reach a current that generates an electromagnetic attraction force sufficient to drive the fuel injection valve 5, and to complete the valve opening operation at an early stage.

Even if the valve is fully opened, the output of the injection pulse generating means 27 makes the transistor 32 conductive, so the electromagnetic coil 23 is excited and the fuel injection valve 5 maintains its open state.

At this time, since the driving voltage v2 of the electromagnetic coil 23 is the minimum necessary low voltage to keep the fuel injection valve 5 open, there is no fear of heat generation.

When the injection pulse disappears after time t3, the transistor 32 becomes non-conductive. Therefore, the driving voltage v2 is no longer applied, the %f,kl coil 23 is demagnetized, and the biasing force of the fuel injector 5 is released and the valve is closed. At this time, the injection pulse that maintains the open state of the fuel injection valve 5 is low.
Since the pressure is a, the influence of residual magnetism is small, and the fuel injection valve 5 closes almost at the same time as the injection pulse disappears.

(Effects of the Invention) As described above, the present invention includes an electromagnetic coil of a fuel injection valve.
When the fuel injection valve opens...from 1 to at least when the valve opens, fuel 11! Is there a reserve lower than the drive voltage that drives the injection valve? L
I set the soil to 710T, so I turned on the fuel injector! l! When a driving voltage of /I is applied, the current flowing through the electromagnetic coil increases due to the application of the preliminary voltage.

Therefore, by opening the fuel injection valve quickly without increasing the drive voltage of the electromagnetic coil, the responsiveness of the valve opening operation can be further improved, and the heat generation of the magnetic coil can be suppressed. It's a monkey.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a fuel injection device for an internal combustion engine to which this invention is applied, Fig. 2 is a block diagram showing a driving device for an electromagnetic fuel injection valve, and Fig. 3 is a schematic diagram of a fuel injection device for an internal combustion engine to which the present invention is applied. There is an operation time chart. 5...Fuel port a injection valve 17--Crank position detection means 23-='Turtle magnet coil 25...Injection valve drive means 26--Injection timing determination means 27-=Injection pulse generation means 28-- , 11α emission time determining means 29...preliminary pulse generation timing determining means 30-.
・Nif pulse generation means Figure 1

Claims (1)

[Claims] A voltage is applied to the electromagnetic coil of a fuel injection valve equipped in an internal combustion engine that injects fuel in synchronization with the opening timing of an intake valve that supplies fuel to the internal combustion engine, and the fuel injection valve opens and fuel is injected. In a fuel injection valve drive device for an internal combustion engine that injects fuel, a preliminary voltage lower than a driving voltage for driving the fuel injection valve is applied to the electromagnetic coil from before the fuel injection valve opens until at least when the fuel injection valve opens. A fuel injection valve drive device for an internal combustion engine.