JPS6143250A - Starting control for diesel engine - Google Patents

Abstract

PURPOSE:To improve starting performance even if the power voltage lowers at a low temperature on starting by controlling a driving actuator for a fuel injection-amount control member to the fuel injection position on start, before a starter starts operation. CONSTITUTION:When starting instruction is applied in a certain cycle, and a start switch 15 is turned-ON, an aimed rack position is calculated according to the characteristic obtained by the governor pattern, and feedback control through the proportional integration calculation is performed so that the aimed position and the actual position of a rack rod 6 accord each other, and a power voltage 17 is read-out, and an ouput value is corrected. When the start switch 15 is turned OFF, the presence of input of a revolution sensor is checked, and if the input of the revolution sensor 12 is present, similar processing is performed. Therefore, when the input of the sensor 12 is present, even if the switch 15 is in OFF state, an actuator 10 can be controlled at the position of the rack rod on start before a driving plug is set after the starting preparation for auxiliary equipment is completed, and the reduction of power voltage before start and the delay of the operation of the actuator due to the slide resistance at low temperature can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a starting control method for a diesel engine, and more particularly to a method for driving an electric actuator that controls a fuel injection amount control member during starting.

[Background of the invention]

Conventionally, the method for starting the drive of an actuator has generally been based on a start switch input or a rotation sensor input. With this method, the electromagnetic force of the actuator decreases due to a decrease in power supply voltage especially at low temperatures, the effect on the position sensor signal, and the delay in actuator operation due to an increase in the sliding resistance of the fuel injection amount control member. There was a problem that occurred. In order to solve these problems, as proposed in Japanese Patent Application Laid-Open No. 58-28546,
There is a method of fully energizing the actuator by inputting a start switch. According to this method, if there is a start switch input, the actuator is continuously energized even if there is no rotation sensor signal input, resulting in a lot of wasted power.

[Purpose of the invention]

The present invention has been made in view of the above points, and its object is to enable a diesel engine to start smoothly even when problems such as a drop in power supply voltage or a drop in temperature occur when starting a diesel engine. The present invention provides a method for controlling the start of an engine.

[Summary of the invention]

The present invention moves an actuator that drives a fuel injection amount control member of a diesel engine to a starting fuel injection amount position after the power is turned on via a control circuit, immediately before or after the completion of system initial processing, and before starting a starter. This control is performed so that the actuator is positioned so as to reduce problems caused to the operation of the actuator due to a drop in power supply voltage, a drop in temperature, etc. at the time of startup.

[Embodiments of the invention]

An embodiment of the diesel engine starting control method according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. The fuel injection pump 1 is connected to an engine (not shown) via a coupling 2, and is driven by the engine at a rotation ratio of 1/2. Fuel is fed from fuel tank 3 to feed pump 4
, the fuel is supplied to the inside of the fuel injection pump 1 through the fuel filter 5, the injection amount is adjusted by the position of the rack rod 6, and the fuel is supplied to the engine cylinder (Fig. (not shown).

The actuator 10 generates an electromagnetic force by passing a current through a coil provided inside the actuator 10 to attract the rack rod 6 in the direction of increasing the injection amount, and a spring (not shown) provided inside the actuator 10 is activated. The rack rod 6 is configured to stop at a balance point between the urging force and the force pushing the rack rod 5 back in the direction of decreasing the injection amount. 11 is a position sensor for this rack rod 6, 12 is a rotation sensor that detects the rotation of the engine, and 17 is a power supply voltage.

The control circuit 13 includes an accelerator position sensor 14, the rotation sensor 12, and the rack rod position sensor 11, which is a fuel injection amount control member. By inputting signals from the start switch 15 and the operating state detection sensor group 16, arithmetic processing is performed using preset engine characteristic values, governor patterns, etc., and the target rack, which is the target fuel injection amount control member position, is set. The rod position is determined, and the actuator 10 is controlled so as to match this position with the actual rack rod position.

FIG. 2 is a flowchart showing the initial processing of the system in this embodiment. Starting with 100 is performed by turning on the power or resetting the system read, and 101
Performs an initial self-check of the system, performs initial input/output processing of the system, and calculates the energization time of the air heater etc. based on the water temperature. At step 102, it is determined whether or not the air heater energization time determined at step 101 is present. If not, at step 108, before starting, a drive flag is set to control the actuator 10 to the rack rod position at the time of startup, and a 4-second timer count value is set. Set. In 103, it is determined whether the air heater energization time counter value obtained in 101 is zero or not. If it is zero, the air heater energization is ended in 107, and if it is not zero, the air heater is energized in 104. Note that activation from 106 is performed at an interrupt timing of 0.2 seconds. Next, in 105, the air heater energization time counter is subtracted by 1, and if the counter value becomes zero, it is determined whether or not it is 0.2 seconds before the end of the air heater energization. In step 108, a drive flag is set. At the same time as these system initialization processes, the senna group 16 is read.

FIG. 3 is a flowchart showing the driving of the actuator 10. At 200, it will start up at a constant cycle, and at 20
At 1, it is determined whether the start switch is ON or OFF, and if it is ON, at 208 the target rack rod position is calculated based on the characteristics determined from the governor pattern shown in FIG. Note that FIG. 4 shows that the typical target rack rod position is determined by the engine speed and the accelerator position, and is corrected by the water temperature at the time of starting, as shown by the chain line. Next te 20
In step 9, feedback control is performed using proportional integral calculation so that the target rack rod position and the actual rack rod position match, and step 2
10 reads the Fi power supply voltage and corrects the output value. Further, in 202, if the start switch is OFF, it is checked whether there is an input from the rotation sensor 12, and if there is an input from the rotation sensor 12, processes 208, 209, and 210 are performed in the same manner as in the above case.

203 monitors the presence or absence of a signal input from the rotation sensor 12 for a certain period of time except before starting, and
If there is no input of 2, it is assumed that the engine has stalled, and 20
5, the driving force of the actuator 10 is turned off. Also, before starting, the drive flag is checked in 204, and if the drive flag is set, the value of the 4-second timer counter is checked in 206, and if 4 seconds have elapsed, the drive flag is cleared in 207.

As described above, according to this embodiment, the start switch 15
Even if it is OFF, if there is an input from the rotation sensor 12, the actuator can be controlled to the starting rack rod position.Moreover, this control is performed only when the start preparations for preheating auxiliary equipment such as the air heater are completed and the drive flag is set. This can eliminate delays in actuator operation due to power supply voltage drop during startup and sliding resistance of the fuel injection amount control member, especially at low temperatures. In addition, if there is no start switch signal input or rotation sensor signal input within a certain period of time after controlling the actuator to the starting fuel injection position, the actuator drive can be temporarily stopped to eliminate the waste of continuous energization. .

〔Effect of the invention〕

As described above, according to the present invention, since the actuator is controlled to the starting fuel injection amount position before starting the starter, starting performance can be improved even when the power supply voltage decreases during starting and at low temperatures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a diesel engine starting control method according to the present invention, FIG. 2 is a flowchart showing system initial processing according to an embodiment of the present invention, and FIG. Flowchart showing, No. 4
The figure is a graph showing a governor pattern. l...Fuel injection pump, 6...Rack rod, 10...
・Actuator, 11... Rack rod position sensor, 1
2... Rotation sensor, 13... Control circuit, 14...
Accelerator position sensor, 15...Start switch, 1
7...Power supply voltage.

Claims (2)

[Claims] 1. A diesel engine start control method includes an actuator for driving a fuel injection amount control member, and the actuator controls the fuel injection amount by aligning the injection amount control member with a target position via a control circuit. A starting control method for a diesel engine, comprising controlling the fuel injection amount control member to a starting fuel injection amount position via the actuator immediately before or after the end of initial processing and before inputting a start switch. 2. 2. The method of controlling the start of a diesel engine according to claim 1, wherein the actuator temporarily stops driving if a start switch signal or a rotation sensor signal is not input for a specific period of time.