JP2007092675A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device, positively discharging generated vapor toward a return passage by performing pulse drive not inducing fuel injection of a solenoid coil, and not degrading startability by letting a control unit reset when power source voltage is dropped in starting an engine. <P>SOLUTION: In the fuel injection device including a fuel injection module 8 sucking, pressurizing and injecting fuel by reciprocating motion of a plunger 102, and a mode judgment means judging before-start-control mode which is a condition before starting the engine based on operation conditions of the engine E, and provided with a control unit 1 giving the fuel injection module drive signal of a pulse width not inducing fuel injection at a time of the before-start-control mode, stop of pulse drive to the fuel injection module 8 not inducing fuel injection is judged based on engine information detected by the control unit 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel injection device, and more particularly to a fuel injection device including a fuel injection module having a function of pressurizing fuel by a reciprocating motion of a plunger and a function of a fuel injection valve, and suitable for fuel control of a two-wheeled vehicle engine. Is.

  In a conventional electronically controlled fuel injection device in which the control unit calculates the fuel supply amount according to the engine speed and load and gives a drive signal to the fuel injection valve, the plunger is reciprocated by electromagnetic force to suck the fuel. Fuel injection modules that inject under pressure have been proposed. (For example, refer to Patent Document 1).

  The fuel injection module energizes the solenoid coil with a drive signal given from the control unit, the plunger pressurizes the fuel and injects the fuel at a predetermined fuel pressure, and then injects next when the plunger is pushed back by the spring. Therefore, the fuel is sucked in.

  A fuel injection device using a fuel injection module has fewer components than a fuel injection device that pressurizes and regulates fuel with a fuel pump and regulator and injects pressurized fuel with an injector. Since it is energized, it has the advantage of low average power consumption, and is particularly suitable for small two-wheeled vehicles with low generator and battery capabilities.

  In addition, in this apparatus, a discharge mechanism is provided in which fuel mixed with vapor (bubbles) is refluxed in advance toward the fuel tank by a return pipe before the fuel pumped by the plunger pump is injected by the injection nozzle. ing.

  Further, when the engine is in an idling operation state, a fuel cut control mode in which fuel is not injected, or in an operation state in which vapor is likely to be generated in the fuel, such as being stopped and the power is turned on, or in a high temperature stop state, the solenoid coil is On the other hand, by conducting pulse energization that does not lead to fuel injection (hereinafter referred to as purge drive and purge drive energization time), the vapor is efficiently discharged, the flow rate of the returned fuel is increased, and the cooling action is enhanced. .

  For this reason, generation | occurrence | production of vapor | steam is suppressed, the fuel injection is stabilized, and also the proposal for improving restart property is also performed. (For example, refer to Patent Document 2).

JP 2001-221137 A JP 2003-227432 A

  Since the conventional fuel injection device is configured as described above, the starter is driven in a state where the power supply voltage is low, and further, when purge driving for discharging the vapor is performed, it flows through the solenoid coil of the fuel injection module There is a problem that the power supply voltage is further reduced by the current, and the voltage is lower than the voltage at which the control unit operates, reset occurs and the startability deteriorates.

  The present invention has been made to solve the above-described problems. The solenoid coil is pulse-driven so as not to inject fuel, and the generated vapor is surely discharged toward the return passage. Another object of the present invention is to provide a fuel injection device that does not impair startability by resetting a control unit in response to a decrease in power supply voltage when starting an engine.

  A fuel injection device according to the present invention includes a fuel injection module that sucks and pressurizes fuel by reciprocating movement of a plunger, and a pre-startup control mode that is a state before starting the engine based on the operating state of the engine And a control unit that provides a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module in the pre-startup control mode. Based on the engine information detected by the engine, it is determined whether to stop driving the pulse that does not lead to fuel injection to the fuel injection module.

  Since the fuel injection device according to the present invention is configured as described above, the vapor is efficiently discharged by continuing the pulse energization time (purging drive energization time) that does not lead to fuel injection to the solenoid coil. Further, the flow rate of the fuel to be recirculated is increased, the cooling action is enhanced, the generation of vapor is suppressed, and the fuel injection is stabilized.

  In addition, if the power supply voltage has dropped, or if the power supply voltage has dropped further due to the start of the engine starter in that state, the control unit will not reset, and the fuel injection drive required for starting will be stable. The engine startability is improved.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a state in which the fuel injection device according to Embodiment 1 is attached to an engine, and FIG. 2 is a schematic diagram showing the configuration and operation of the fuel injection module.

  In FIG. 1, the control unit 1 measures an intake air temperature sensor 2 that measures the temperature of intake air of the engine E, a throttle position sensor 4 that measures the opening of the throttle valve 3, and an intake air pressure downstream of the throttle valve 3. From the information of the intake pressure sensor 5, the engine temperature sensor 6 that measures the wall temperature of the engine E, and the crank angle sensor 7 that also measures the crank position of the engine E, an appropriate fuel injection timing and fuel injection amount are calculated, and fuel injection is performed. A drive signal is output to the module 8. Similarly, an appropriate ignition signal is output to the ignition coil 9 from the information of the various sensors.

  As shown in FIG. 2, the fuel injection module 8 moves the plunger 102 downward in the figure as indicated by an arrow by electromagnetic force generated by energizing the solenoid coil 101 inside the fuel injection module 8, thereby From the feed pipe 11 and the fuel filter 12, the fuel supplied through the suction side check valve 106 is pressurized as shown by an arrow c, and injected at a predetermined pressure as shown by an arrow b.

  When energization of the solenoid coil 101 is stopped, the plunger 102 is pushed upward in the drawing by a return spring (not shown) to return to the original position. At this time, as shown by an arrow c, the plunger 102 passes through the suction side check valve 106 to the next. Aspirate the fuel for injection. Excess fuel and air (vapor) contained in the fuel flow out from the return passage check valve 103 in FIG. 2 as indicated by an arrow a, and are returned to the fuel tank 10 through the return pipe 13.

  This will be described in more detail. When energization to the solenoid coil 101 is started by the drive signal from the control unit 1, the plunger 102 moves downward as shown by an arrow in the drawing to pressurize the fuel. At that time, until the plunger 102 reaches the return passage check valve 103 (invalid injection time), the fuel (gasoline) in the fuel injection module partially passes through the return passage check valve 103 and flows as indicated by an arrow a. It flows out of the fuel injection module. Further, the vapor in the fuel injection module is also discharged out of the fuel injection module by this flow. (Purge injection control)

  When the drive signal from the control unit 1 further continues and energization to the solenoid coil 101 continues, the plunger 102 further moves downward in FIG. 2 to pressurize the fuel, and when the predetermined pressure is exceeded, the fuel injection module The fuel inside passes through the injection side check valve 104 and the injection port 105 and is injected into the engine E as shown by the arrow b.

  Thereafter, when energization of the solenoid coil 101 is completed, fuel is sucked through the suction side check valve 106 as shown by an arrow c when the plunger 102 returns upward in FIG. 2 by a return spring (not shown).

  FIG. 3 is a schematic diagram showing a drive signal for energizing the solenoid coil 101 inside the fuel injection module 8 and the operation of the fuel injection module 8. FIG. 3A shows the drive signal, and FIG. 3B shows the operation. Show.

  When a drive signal as shown in FIG. 3A is sent from the control unit 1 to the fuel injection module 8 and energization of the solenoid coil 101 in the fuel injection module 8 is started, as shown in FIG. 2, the plunger 102 in the fuel injection module 8 moves downward in FIG. 2 to pressurize the fuel, and the fuel is injected at a predetermined pressure. When moving upward and returning to the original position, fuel is sucked as described above.

  The drive signal given to the fuel injection module 8 by the control unit 1 is corrected by the atmospheric pressure, the intake air temperature, the engine temperature and the throttle operation to the basic injection time for determining the basic injection amount, and further, the invalid injection time is added. This invalid injection time is the time until the fuel is pressurized and injected in the fuel injection module 8 as shown in FIG.

  Generally, when the intake air temperature or the engine temperature is low and the vehicle is in an accelerating state by a throttle operation, the drive signal time becomes long. This drive signal is output to the fuel injection module 8 in synchronization with crank rotation at a predetermined timing programmed in advance in a storage device (not shown) of the control unit 1 based on the crank angle information detected by the crank angle sensor 7. The

  FIG. 4 is a schematic diagram showing the operation of the fuel injection module 8 according to Embodiment 1 when the engine is started by the engine starting device from when the engine is stopped. FIG. 4A is a diagram showing the power ON / OFF state. (b) is a diagram showing ON / OFF states of the start switch of the engine starting device, (c) is a diagram showing an output signal of the crank angle sensor 7, and (d) is a drive pulse applied to the solenoid coil of the fuel injection module 8. (E) is a current of a solenoid coil, (f) is a figure showing the situation of fuel injection.

  As shown in FIG. 4A, when the power of the fuel injection device is turned on, as shown in FIG. 4D, a drive signal (pulse) corresponding to the invalid injection time is sent to the fuel injection module 8 at predetermined intervals. As shown in FIG. 4 (e), the plunger pump 102 is driven by energizing the solenoid coil, and the vapor in the fuel injection module 8 is forcibly discharged out of the fuel injection module using the discharge mechanism. Furthermore, electric power is stored in a storage capacitor (not shown).

  When the engine stop state continues, purge injection by the drive signal for this invalid injection time is continued for a predetermined time or a predetermined number of times, and then ended. However, as shown in FIG. If the start switch of the engine starter is turned ON within the number of times, the control unit 1 detects the state and stops the purge injection.

  Then, when the engine starts rotating by the engine starter and the engine rotation is detected by the crank angle sensor as shown in FIG. 4C, the engine is detected with respect to the fuel injection module 8 as shown in FIG. A drive signal corresponding to the injection time for supplying the fuel necessary for start-up is given, and purge injection that continues for a predetermined time or a predetermined number of times after the power of the fuel injection device is turned on is not resumed.

  FIG. 5 shows a fuel injection module when the engine is started by the engine starter from when the engine is stopped when the purge injection by the drive signal for the invalid injection time is stopped according to the power supply voltage state of the fuel injector according to the first embodiment. FIG. 8 is a schematic diagram illustrating the operation of FIG. 8, similarly to the case of FIG. 4, when the power of the fuel injection device is turned on, a drive signal corresponding to the invalid injection time is given to the fuel injection module 8 at predetermined intervals.

  When the engine starting device is started as shown in FIG. 5 (b), a large amount of electric power is generally required for the starting, so the power supply voltage of the fuel injection device as shown in FIG. 5 (c). Decreases temporarily. The control unit 1 monitors the power supply voltage. When it is detected that this voltage has dropped and has fallen below the determination voltage, the purge injection by the drive signal for the invalid injection time is stopped as shown in FIG. .

  As shown in FIG. 6 (b), when the engine starts rotating and the control unit 1 detects the crank angle sensor signal for the first time, the fuel injection device is turned on as shown in FIG. 6 (c). Then, the purge injection that is continued for a predetermined time or a predetermined number of times may be stopped.

  Further, as shown in FIG. 7 (b), after the engine starts rotating and the control unit 1 detects the crank angle sensor signal for the first time, a reference for determining the fuel injection timing and ignition control timing necessary for engine control. When the crank angle is detected, purge injection that is continued for a predetermined time or a predetermined number of times after the power of the fuel injection device is turned on may be stopped as shown in FIG.

It is a schematic block diagram which shows the state with which the fuel-injection apparatus by Embodiment 1 of this invention was attached to the engine. FIG. 3 is a schematic diagram showing the configuration and operation of the fuel injection module according to Embodiment 1. FIG. 3 is a schematic diagram showing a drive signal and operation to a fuel injection module according to Embodiment 1. It is a schematic diagram which shows the state of the start switch of the engine starting apparatus in Embodiment 1, a drive signal, and operation | movement of a fuel-injection module. It is a schematic diagram which shows the state of the power supply voltage in Embodiment 1, a drive signal, and operation | movement of a fuel-injection module. FIG. 5 is a schematic diagram showing a crank angle sensor signal, a drive signal, and an operation of the fuel injection module in the first embodiment. FIG. 6 is a schematic diagram showing a reference crank angle detection state, a drive signal, and an operation of a fuel injection module in the first embodiment.

Explanation of symbols

1 control unit, 2 intake air temperature sensor, 3 throttle valve,
4 throttle position sensor, 5 intake pressure sensor, 6 engine temperature sensor,
7 Crank angle sensor, 8 Fuel injection module, 9 Ignition coil,
10 fuel tank, 11 feed pipe, 12 fuel filter,
13 return pipe, E engine, 101 solenoid coil,
102 Plunger, 103 Return passage check valve,
104 injection side check valve, 105 injection port, 106 suction side check valve.

Claims (5)

A fuel injection module that sucks and pressurizes fuel by reciprocating movement of the plunger, and mode determination means for determining a pre-startup control mode that is a state before starting the engine based on the operating state of the engine A fuel injection device comprising: a control unit that gives a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module during the pre-start control mode;
A fuel injection device that determines stop of driving of a pulse that does not lead to fuel injection to the fuel injection module based on engine information detected by the control unit. A fuel injection module that sucks and pressurizes fuel by reciprocating movement of the plunger, and mode determination means for determining a pre-startup control mode that is a state before starting the engine based on the operating state of the engine A fuel injection device comprising: a control unit that gives a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module during the pre-start control mode;
The fuel injection device, wherein when the control unit detects engine start by input of a switch signal for starting the engine start device, driving of a pulse that does not lead to injection to the fuel injection module is stopped. A fuel injection module that sucks and pressurizes fuel by reciprocating movement of the plunger, and mode determination means for determining a pre-startup control mode that is a state before starting the engine based on the operating state of the engine A fuel injection device comprising: a control unit that gives a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module during the pre-start control mode;
When the control unit detects a voltage drop due to power supply voltage input, the fuel injection device stops driving pulses that do not result in injection to the fuel injection module. A fuel injection module that sucks and pressurizes fuel by reciprocating movement of the plunger, and mode determination means for determining a pre-startup control mode that is a state before starting the engine based on the operating state of the engine A fuel injection device comprising: a control unit that gives a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module during the pre-start control mode;
The fuel injection device, wherein when the control unit detects an engine rotation by a signal input of a crank angle sensor, the fuel injection module stops driving a pulse that does not lead to injection. A fuel injection module that sucks and pressurizes fuel by reciprocating movement of the plunger, and mode determination means for determining a pre-startup control mode that is a state before starting the engine based on the operating state of the engine A fuel injection device comprising: a control unit that gives a drive signal having a pulse width that does not lead to fuel injection to the fuel injection module during the pre-start control mode;
When the control unit detects a reference crank angle that determines ignition and fuel injection timing required for engine control by inputting a signal from a crank angle sensor, driving of the fuel injection module that does not lead to injection is stopped. The fuel-injection apparatus characterized by the above-mentioned.

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