JP2017145760A - Fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax seizing of a fuel injection valve while avoiding consumption of fuel.SOLUTION: The fuel injection control device outputs a drive signal to a fuel injection valve for an internal combustion engine to control fuel injection from the fuel injection valve. The fuel injection control device outputs a pre-heating drive signal to the fuel injection valve to prevent the fuel injection valve from opening before startup of an internal combustion engine.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel injection control device.

  Patent Document 1 below discloses an engine fuel injection device that can reliably start the engine by relaxing sticking of the fuel injection valve regardless of moisture icing or the like. As shown in FIG. 5 of Patent Document 1, this fuel injection device is provided with an injector (fuel injection valve) by supplying an injection instruction signal a plurality of times at a relatively short period before the engine is started. ) Is forcibly actuated, thereby preliminarily mitigating sticking of the movable parts of the injector due to icing or intrusion of lubricating oil.

JP 2007-285152 A

  By the way, in the above prior art, in order to ease the sticking of the movable part of the injector in advance, the injector is forcibly driven with an injection instruction signal having a pulse width equivalent to the injection instruction signal during normal operation. The injector actually opens. That is, in the prior art, since fuel is actually supplied into the combustion chamber of the engine before the engine is started, the fuel is wasted.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to alleviate sticking of a fuel injection valve while avoiding fuel consumption.

  In order to achieve the above object, in the present invention, as a first solving means related to a fuel injection control device, a fuel for controlling fuel injection of the fuel injection valve by outputting a drive signal to the fuel injection valve of the internal combustion engine. The injection control device adopts a means for outputting a preheating drive signal that does not open the fuel injection valve to the fuel injection valve before starting the internal combustion engine.

  In the present invention, as a second solving means relating to the fuel injection control device, in the first solving means, the preheating drive signal is a pulse train having a pulse width that does not open the fuel injection valve. adopt.

  In the present invention, as a third solving means relating to the fuel injection control device, in the first solving means, the preheating drive signal is a signal in which an amplitude at which the fuel injection valve does not open continues for a predetermined period. The method of being is adopted.

  In the present invention, as a fourth solving means related to the fuel injection control device, in any one of the first to third solving means, a preheating instruction for the fuel injection valve is inputted from the operation portion of the internal combustion engine. In this case, a means of outputting the preheating drive signal is employed.

  In the present invention, as a fifth solving means related to the fuel injection control device, in any one of the first to fourth solving means, a signal for notifying the internal combustion engine of the preheating of the fuel injection valve is output to the notifying part of the internal combustion engine. Adopt the means to do.

 According to the present invention, since the preheating drive signal with the specification that the fuel injection valve does not open before the start of the internal combustion engine is output to the fuel injection valve, heating (preheating) is performed without opening the fuel injection valve. be able to. Therefore, according to the present invention, it is possible to reduce the sticking of the fuel injection valve by heating (preheating) while avoiding the consumption of fuel due to the opening of the fuel injection valve.

It is a block diagram which shows the function structure of the fuel-injection control apparatus A which concerns on one Embodiment of this invention. It is a 1st flowchart which shows operation | movement of the fuel-injection control apparatus A which concerns on one Embodiment of this invention. It is a timing chart which shows operation | movement of the fuel-injection control apparatus A which concerns on one Embodiment of this invention. It is a 2nd flowchart which shows operation | movement of the fuel-injection control apparatus A which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the fuel injection control apparatus A according to the present embodiment includes an I / O circuit 1, an A / D converter 2, an ignition circuit 3, an injector drive circuit 4, a valve drive circuit 5, a memory 6 and a CPU. (Central Processing Unit) 7 is provided. This fuel injection control device A is intended for control of an internal combustion engine E such as a vehicle engine.

  The internal combustion engine E includes, as components related to injection control by the fuel injection control device A, a preheating switch a (operation unit), an outside air temperature sensor b, a throttle angle sensor c, and a preheating lamp d as shown in FIG. (Notification part), the ignition coil e, the injector f (fuel injection valve), and the throttle valve g are provided. The fuel injection control device A is a device that controls the fuel injection of the injector f by outputting a drive signal to the injector f of the internal combustion engine E having such components.

  For convenience, the internal combustion engine E will be described first. The internal combustion engine E is a machine that generates power by burning predetermined fuel, for example, a gas engine that uses combustible gas as fuel. The preheating switch a is an operation switch for the driver to instruct the fuel injection control apparatus A to perform forced preheating of the injector f before starting the internal combustion engine E, and is provided on the instrument panel (so-called instrument panel) of the vehicle. . The preheating switch a outputs a preheating instruction signal to the I / O circuit 1 of the fuel injection control device A.

  The outside air temperature sensor b is a detector that detects the ambient temperature Ta of the internal combustion engine E, and outputs an outside air temperature signal indicating the ambient temperature Ta to the A / D converter 2 of the fuel injection control device A. The throttle angle sensor c is a detector that detects the opening (throttle angle) of the throttle valve g that adjusts the flow rate of the combustion air taken into the internal combustion engine E, and the throttle angle signal indicating the throttle angle is A / D. Output to the converter 2.

  The preheating lamp d is a lamp that indicates the preheating state of the injector f described above based on the lighting signal input from the I / O circuit 1, and is provided in the vicinity of the preheating switch a described above. The ignition coil e is a transformer that applies a high discharge voltage to the ignition plug of the internal combustion engine E, and generates the high discharge voltage by boosting the ignition signal input from the ignition circuit 3.

  The injector f is a fuel injection valve that operates based on an injector drive signal input from the injector drive circuit 4, and adjusts the amount of fuel supplied to the combustion chamber of the internal combustion engine E. The throttle valve g is a butterfly valve that adjusts the intake air amount of combustion air into the combustion chamber of the internal combustion engine E, and adjusts the intake air amount based on a valve drive signal input from the valve drive circuit 5.

  The I / O circuit 1 is a kind of signal conversion circuit, which converts a preheating instruction signal (analog signal) input from the preheating switch a into a digital signal and outputs the digital signal to the CPU 7, and a lighting instruction signal input from the CPU 7. (Digital signal) is converted into a lighting signal (analog signal) and output to the preheating lamp d.

  The A / D converter 2 converts the outside air temperature signal input from the outside air temperature sensor b and the throttle angle signal input from the throttle angle sensor c, which are analog signals, into digital signals and outputs them to the CPU 7. That is, the A / D converter 2 sequentially outputs the outside air temperature data indicating the outside air temperature of the internal combustion engine E and the throttle angle data indicating the throttle angle of the throttle valve to the CPU 7 in a predetermined order.

  The ignition circuit 3 is a drive circuit for the ignition coil e, generates an ignition signal based on the ignition instruction signal input from the CPU 7, and outputs the ignition signal to the ignition coil e. The injector drive circuit 4 generates an injector drive signal based on the injection instruction signal input from the CPU 7 and outputs it to the injector f. The valve drive circuit 5 generates a valve drive signal based on the operation instruction signal input from the CPU 7 and outputs it to the throttle valve g.

  The memory 6 is a semiconductor storage device composed of a ROM and a RAM. The memory 6 stores in advance a control program executed by the CPU 7, control data necessary for executing the control program, and the like. The calculation result is temporarily stored.

  The CPU 7 is a semiconductor arithmetic device that exhibits a control function of the internal combustion engine E by executing a control program. The CPU 7 executes preheating control of the injector f prior to normal control of the internal combustion engine E as will be described later. This preheating control is a characteristic control function of the fuel injection control apparatus A according to the present embodiment.

  Next, the operation of the fuel injection control apparatus A according to the present embodiment, particularly the preheating control operation of the injector f will be described in detail.

  First, the preheating control operation shown in FIG. 2 will be described. When the power (ECU power) is turned on to the fuel injection control device A from the battery attached to the internal combustion engine E, the CPU 7 performs the preheating control process for the injector f shown in FIG. Execute. That is, in this preheating control process, the CPU 7 first takes in the outside air temperature data, that is, the ambient temperature Ta of the internal combustion engine E from the A / D converter 2 (step S1).

  When the CPU 7 takes in the ambient temperature Ta, the CPU 7 determines whether or not the ambient temperature Ta is equal to or lower than a temperature threshold value Tr previously stored in the memory 6 as control data (step S2). When the determination in step S2 is “Yes”, that is, when the ambient temperature Ta is equal to or lower than the temperature threshold value Tr, the CPU 7 turns on the preheating lamp d by outputting a lighting instruction signal to the I / O circuit 1. (Step S3). Then, the CPU 7 starts heating (preheating) of the injector f by outputting a preheating instruction signal to the injector driving circuit 4 (step S4). If the determination in step S2 is “No”, that is, if the ambient temperature Ta is higher than the temperature threshold value Tr, the CPU 7 ends the preheating control process.

  Here, the temperature threshold value Tr is a temperature slightly higher than the temperature at which moisture or the like adhering to the injector f solidifies. That is, when the ambient temperature Ta is higher than the temperature threshold Tr, the movable part of the injector f is very unlikely to stick, but when the ambient temperature Ta is lower than the temperature threshold Tr, the movable part of the injector f is There is a high risk of sticking. Note that such a temperature threshold value Tr can be arbitrarily set by the driver by using, for example, an operation setting unit (not shown) provided on the instrument panel of the vehicle.

  As a result of step S3, the I / O circuit 1 outputs a lighting signal to the preheating lamp d, so that the preheating lamp d in the extinguished state is lit. Then, the preheat lamp d is turned on to notify the vehicle driver that the injector f is being preheated.

  As a result of step S4, the injector driving circuit 4 outputs the first driving current I1 (preheating driving signal) for injector preheating to the injector f. The first drive current I1 is a pulse train made up of a plurality of pulse signals having a predetermined pulse width as shown in FIG. 3. As a result of step S4, the first pulse signal is supplied (powered) to the injector f. Is started. That is, as a result of step S4, the first drive current I1 rises from low (non-power supply state) to high (power supply state).

  Then, when the process of step S4 is completed, the CPU 7 determines whether or not the elapsed time (power supply time) from the start of power supply is equal to or greater than the energization threshold value H1 stored in advance in the memory 6 as control data ( Step S5). When the determination in step S5 is “Yes”, the CPU 7 stops the power supply to the injector f by stopping the output of the preheating instruction signal to the injector drive circuit 4 (step S6). As a result, the output of the first pulse signal in the first drive current I1 shown in FIG. 3 is completed.

  When the process of step S6 is completed, the CPU 7 determines whether or not the number of output times of the pulse signal has reached a predetermined number N stored in advance in the memory 6 as control data (step S7). If the determination in step S7 is “No”, the CPU 7 causes the injector drive circuit 4 to output the next pulse signal in the first drive current I1 by repeating the process in step S4 described above. As a result of the series of steps S4 to S7, N pulse signals are output from the injector drive circuit 4 to the injector f as shown in FIG.

  Here, the energization threshold value H1 is an amount that determines the pulse width of each pulse signal in the first drive current I1. This pulse width is set to a time width that does not open the injector f. The first drive current I1 cannot cause the injector f to open because the pulse width of each pulse signal is narrow, but can cause the injector f to generate heat.

  The first drive current I1 (pulse train) is a form of the preheating drive signal. The preheating drive signal may be the second drive current I2 shown in FIG. 3, for example, as long as the injector f can heat the injector f but is set so that the injector f does not open. The second drive current I2 is a signal that continues for a predetermined period in which the amplitude at which the injector f is not opened is stored in advance in the memory 6 as control data. The second driving current I2 has a small amplitude, so that the injector f cannot be opened, but the injector f can generate heat.

  According to the fuel injection control apparatus A according to this embodiment, before the start of the internal combustion engine E, the injector f is opened by supplying the first drive current I1 or the second drive current I2 to the injector f. It is possible to heat (preheat) without causing it. According to the fuel injection control apparatus A, the injector f generates heat due to the first drive current I1 or the second drive current I2. Therefore, the movable part of the injector f is fixed due to moisture coagulation, that is, the injector f It is possible to avoid malfunction.

 By the way, when the determination in step S7 is “Yes”, the CPU 7 turns off the preheating lamp d by stopping the output of the lighting instruction signal to the I / O circuit 1 (step S8). As a result, the I / O circuit 1 stops outputting the lighting signal to the preheating lamp d, so that the lighting preheating lamp d is turned off. By turning off the preheating lamp d, the vehicle driver can recognize that the preheat treatment of the injector f has been completed.

 The period during which the preheating lamp d is lit is the preheating period shown in FIG. During this preheating period, the CPU 7 does not allow the internal combustion engine E to start. That is, the CPU 7 does not start the normal control process even if the driver gives an instruction to start the internal combustion engine E.

Next, the preheating control operation shown in FIG. 4 will be described.
Note that the preheating control operation in FIG. 2 autonomously determines whether or not the preheating of the injector f is possible based on the ambient temperature Ta, but the preheating control operation in FIG. 4 is performed by the driver operating the preheating switch a. Based on this, the pre-heat treatment of the injector f is forcibly performed.

  In this preheating control operation, the CPU 7 first determines whether or not the preheating switch a has been operated (step S11). Then, when this determination is “Yes”, the CPU 7 executes the following steps S12 to S17. Note that the processes in steps S12 to S17 are the same as the processes in steps S3 to S8 in FIG.

  According to the preheating control operation of FIG. 4, before the start of the internal combustion engine E, the preheat treatment of the injector f is performed based on the operation instruction of the driver, so the injector is independent of the ambient temperature Ta of the internal combustion engine E. The heating (preheating) of f is executed, and hence the sticking of the movable part of the injector f due to moisture solidification or the like, that is, the malfunction of the injector f can be avoided.

  In the fuel injection control apparatus A according to this embodiment, when the driver gives an instruction to start the internal combustion engine E after the above-described preheating control operation of the injector f is completed, the CPU 7 starts a normal control process. In this normal control process, the CPU 7 outputs an operation instruction signal generated based on the throttle angle data of the throttle valve g input from the A / D converter 2 to the valve drive circuit 5 and drives the injection instruction signal to the injector. The signal is output to the circuit 4 and the ignition instruction signal is output to the ignition circuit 3.

  As a result, the valve drive circuit 5 outputs the operation signal and the throttle valve g to set the flow rate of the combustion air taken into the combustion chamber of the internal combustion engine E, and the injector drive circuit 4 sends the injection signal to the injector f. Is output to the combustion chamber, and the ignition circuit 3 outputs an ignition signal to the ignition coil e so that the fuel in the combustion chamber burns at a desired timing. That is, the internal combustion engine E exerts power when the throttle valve g, the injector f, the ignition coil e, and the like work together by the normal control processing by the fuel injection control device A.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the first driving current I1 or the second driving current I2 is adopted as the preheating driving signal that does not open the injector f (fuel injection valve). It is not limited to this.

(2) In the above embodiment, the pulse width of each pulse signal and the number of each pulse signal in the first drive current I1 are determined based on the energization threshold value H1 and the predetermined number N stored in advance in the memory 6 as control data. Although set, the present invention is not limited to this. By setting the energization threshold value H1 and the predetermined number N from an operation setting unit (not shown), the driver may be able to appropriately specify the energization threshold value H1 and the predetermined number N.

(3) In the above embodiment, the duration of the first drive current I2 is stored in advance in the memory 6 as control data, but this duration can also be appropriately designated by the driver by operating the operation setting unit. You may do it.

1 I / O circuit 2 A / D converter 3 Ignition circuit 4 Injector drive circuit 5 Valve drive circuit 6 Memory 7 CPU
a Preheat switch (operation part)
b Outside air temperature sensor c Throttle angle sensor d Preheating lamp (notification unit)
e Ignition coil f Injector (fuel injection valve)
g Throttle valve

Claims (5)

A fuel injection control device for controlling fuel injection of the fuel injection valve by outputting a drive signal to a fuel injection valve of an internal combustion engine,
A fuel injection control device that outputs to the fuel injection valve a preheating drive signal that does not open the fuel injection valve before starting the internal combustion engine.   2. The fuel injection control device according to claim 1, wherein the preheating drive signal is a pulse train having a pulse width that does not open the fuel injection valve.   2. The fuel injection control device according to claim 1, wherein the preheating drive signal is a signal in which an amplitude at which the fuel injection valve does not open continues for a predetermined period.   The fuel injection control according to any one of claims 1 to 3, wherein the preheating drive signal is output when a preheating instruction of the fuel injection valve is input from an operation unit of the internal combustion engine. apparatus. The fuel injection control device according to any one of claims 1 to 4, wherein a signal for notifying the preheating of the fuel injection valve is output to a notification unit of the internal combustion engine.

Images