JPS6081448A - Fuel injection method of diesel-engine - Google Patents

Abstract

PURPOSE:To prevent a vehicle from abruptly starting upon backward movement, by injecting a basic injection amount of fuel upon forward movement of the vehicle, and as well by injecting an amount of fuel which is slightly smaller than the basic fuel injection amount, upon backward movement of the vehicle. CONSTITUTION:When it is judged that a shift switch is turned on, a backward accelerator opening degree conversion value AccR is compoted at the step 303. meanwhile, when the shift switch is turned off, a forward accelerator opening degree conversion value AccF is computed at the step 304. A basic fuel injection amount is compensated to obtain a fuel injection amount Q at the step 305. The conversion value AccR is smaller than an actual accelerator opening degree Acc. A fuel injection timing TI is obtained at the step 306, and fuel injection is carried out at the step 307. Thus, the fuel injection amount upon backward movement of the vehicle is reduced so that abrupt start may be prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a fuel injection method for a diesel engine, and particularly to a diesel engine that performs full fuel injection based on a basic fuel injection amount determined by an accelerator opening and an engine rotation speed. This invention relates to a fuel injection method.

[Background of the invention]

Conventionally, the basic fuel injection amount is determined entirely based on the accelerator opening degree and engine speed, and the basic fuel injection amount is corrected according to intake air temperature, engine cooling water temperature, etc. to determine the fuel injection amount, and the fuel injection amount is determined based on this fuel injection amount. Diesel engines are known that inject fuel by controlling the position of a spill ring. In this diesel engine, optimal fuel is injected depending on the engine operating state.

However, if the accelerator opening and engine speed are the same, the basic fuel injection amount will be the same when the vehicle is moving forward and when reversing, and depending on how the clutch is connected, the vehicle may suddenly start backwards when reversing. , a problem arises in that safety cannot be ensured when reversing.

Transmission gear ratio when reversing to solve this problem? Although it is conceivable to set it to a small value, the problem arises that the driving force when reversing decreases and the vehicle speed increases.

[Purpose of the invention]

The present invention has been made to solve the above problems, and an object of the present invention is to provide a complete fuel injection method for a diesel engine that ensures safety when a vehicle is reversing.

[Structure of the invention]

In order to achieve the above object, the present invention provides a fuel injection method for a diesel engine that injects a difference in fuel based on a conventional basic fuel injection amount, in which the amount of fuel injection when the vehicle is moving backward is greater than the amount of fuel injection when the vehicle is moving forward. This is a reduced amount. Here, the basic fuel injection amount increases as the accelerator opening increases if the engine rotational speed is constant, and decreases as the engine rotational speed increases if the accelerator opening remains constant. By converting the accelerator opening when the vehicle is moving forward from the accelerator opening when the vehicle is moving forward, the basic fuel injection amount can be calculated by converting the accelerator opening at By converting the basic fuel injection amount to a value that is larger than the rotational speed, the fuel injection sensitivity when the vehicle is moving backward can be made smaller than the fuel injection amount when the vehicle is moving forward. In addition, two basic fuel injection quantities are defined: a basic fuel injection quantity for backing up and a basic fuel injection quantity for forwarding, and the basic fuel injection quantity for backing up is smaller than the basic fuel injection quantity for going forward. By setting this value, the fuel injection amount when the vehicle is moving backward can be made smaller than the fuel injection amount when the vehicle is moving forward.

According to the above-mentioned invention, the amount of fuel injected when the vehicle backs up is reduced, and this fuel injection is changed depending on the opening degree and engine speed, so the vehicle can back up without running out of output torque. This has the effect of being able to prevent a sudden start.

[Embodiments of the invention]

Next, a diesel engine equipped with a fuel injection system to which the present invention is applied will be explained in detail.

The fuel injection pump 1 includes a drive shaft 101 that is driven by an engine, a gear 102 and a roller 103 provided in the lead part of the drive shaft 101, a cam plate 104 loosely fitted to the roller 103, and an internal It has a spill port 105 and is nonnom play)
a plunger 106 coupled to the engine 104 to send fuel to the injection nozzle 2 of the engine; a cam plate 104 and the plunger 106t; a spring 107 that always biases leftward in VC in FIG. 1;
and a fuel pump 110 that sends to the timer piston 109
, a timer position sensor 111 that electrically detects the position of the timer piston/109, a timing control valve 112 that determines advance angle adjustment, and an electromagnetic sensor as a rotation speed sensor that outputs a pulse signal according to the rotation speed of the gear 102. A big amp sensor 113 and a spill ring 11 that is slidably attached to the outer peripheral surface of the granger 106 and adjusts the injection amount.
4 and its spill ring 114f: the pusher 115 and the coil 11 that are driven and connected to the spill ring 114
Linear solenoid 117 consisting of 6 and spill link 1
a spill position sensor 118 that detects the amount of movement of the granger 14; a fuel cut solenoid valve 121 that controls the fuel supply to the high pressure chamber 108; It consists of a delivery pulp 122 that prevents backflow and dripping, and a regulating knob 123 that adjusts the fuel pressure inside the pump.

The drive shaft 101 is connected to the rotation of the engine. It drives the rotation 1-1 fuel pump 110, and also drives the plunger 106 and cam grate 104, which are integrally connected, through the roller 103. Cam plate 104
The granger 106 reciprocates left and right in FIG. 1 depending on the contact state between the cam surface of the cam plate 104 and the roller 103 which is fixed in the axial direction of the drive shaft 101. When the plunger 106 moves to the left, fuel is guided into the high pressure chamber 108 and the plunger 106
6 moves to the right, the fuel is crystallized in the high pressure chamber 108, and the high pressure fuel is guided to the injection nozzle 2 via the delivery nozzle (lube 122).
When 6 moves, the fuel of the high Ft plan xos spills over to 1
・Fuel P+ flows out from 105 and injection of fuel P+ from nozzle 2 is stopped. The fuel injection amount is determined by the position of the spill link 114 positioned by the linear solenoid 117.Furthermore, the timing of fuel injection is determined according to the position of the timer piston 109, but the timing control valve 112 By arbitrarily selecting the opening degree of the control valve 112, the fuel pressure acting on the timer piston 109 can be controlled, thereby controlling the timing of fuel injection.For example, in the constant speed rotation range, the opening degree of the control valve 112 can be made small By applying a relatively high pressure to the timer piston 109, a large advance angle can be obtained.

Further, the distribution of fuel to each cylinder is performed by rotating the plunger 106. To be more specific, the plunger 106 has distribution holes formed in the number of cylinders.
Further, the cam plate 104 is formed with protrusions corresponding to the number of cylinders, and each time the protrusion of the cam plate 104 rides on the roller 103, high-pressure fuel flows through the distribution hole of the pusher 106 through the delivery pulp 122. The fuel is fed under pressure to the nozzle 2 of each cylinder and injected. Note that the excess fuel in the pump flows out through the orifice 123.

The control circuit 3 includes a rotational speed signal SN detected by the rotational speed sensor 113, a spill position signal Ss detected by the spill position sensor 118, a timer piston position signal ST detected by the timer position sensor 111, and the intake manifold 4. An intake air temperature signal SA detected by the intake air temperature sensor 5 provided in the intake manifold 4, an intake pressure signal Sp detected by the intake air pressure sensor 6 provided in the intake manifold 4, and a coolant temperature from the temperature sensor 7 that detects the temperature of the engine coolant. The signal Sw, the chamber temperature signal SC detected by the chamber temperature sensor 8, the exhaust temperature signal SE detected by the exhaust temperature sensor 9, and the accelerator opening from the accelerator sensor 11 which detects the accelerator opening from the amount of depression of the accelerator 10. Fi M S A CC and the vehicle speed signal Sv3 detected by the vehicle speed sensor 12 are supplied, and this control circuit 3 controls the linear renoid 117, solenoid pulp 121, and timing control valve 112, respectively, thereby controlling the fuel injection amount and Fuel injection timing is controlled according to operating conditions.

That is, the fuel cut-off remade pulp 121 is energized when the starter switch is on, thereby allowing fuel to be supplied to the high pressure chamber 108, and is demagnetized when the starter switch is off, so that fuel cannot be supplied to the high pressure chamber 108. Be cut off. Further, the IJ near lens 117 is also driven by the injection amount control signal from the control circuit 3, and moves the spill ring 114 to a predetermined position. Further, the timing control valve 112 is driven by a timing control signal from the control circuit 3, and the valve opening degree is arbitrarily selected.

FIG. 2 shows a detailed configuration example of the control circuit 3 shown in FIG. Referring to FIG. 2, a read-only memory (ROM) 32 stores processing programs and monitor programs for executing various processes, and temporarily stores calculation contents, output contents of each sensor, etc. In addition, a random access memory IJ (RAM) 33 having a backup memory 33A that continues to store calculation contents, setting values, etc. even when the power is turned off, and an input circuit 34 are connected to the pass line 3.
It is connected to a central processing unit (CPU) 31 via 5, and constitutes a so-called microcomputer.

The analog signals from the above-mentioned sensors 5, 6, 7, 8, 9, 11° 111 and 118 are sent to the buffer 4, respectively.
0,41,42,43.44゜45:46A and 46B
'i is supplied to a multiplexer (MPX) 47, and one of them is selected as desired. MPX4
7 is an analog-digital converter (A/D converter) 48
is connected, converts the analog signal sound from the MPX 47 into a digital signal, and supplies the digital signal to the input/output circuit 34. The rotational speed signal sN from the engine rotational speed sensor 113 and the vehicle reverse signal SVS from the shift switch 12, which turns the shift lever on in the reverse range and off in other ranges, are sent to the CPU 3 via the waveform shaping circuit 49.
1.

CPU 31, injection amount control actuator drive circuit 51
(2. Controls the fuel injection pump 1.

The actuator drive circuit 51 includes a linear solenoid 11
7. A drive circuit 52 that drives the drive circuit 52, a servo amplifier 53 that supplies drive signals to the drive circuit 52, and a digital-to-analog converter that converts all digital signals from the CPU 31 into analog signals and supplies analog signals to the servo amplifier 53. (D/A converter) 54. The servo amplifier 53 outputs a drive signal based on two signals: an analog signal Ss from the spill position sensor 118 and an analog signal from the D/converter 54.

Further, the CPU 311' is fully connected to drive circuits 55 and 56, and these drive circuits 55 and 56 have a timing control valve 112 and a fuel cut solenoid valve 12, respectively.
Connect to 1. Note that 50A is a clock oscillator.

The ROM 32 of the upper M'b contains a map of the accelerator opening conversion value shown in Figure 4, a map of the basic fuel injection amount Qo determined by the accelerator opening ACC and engine speed NE as shown in Figure 6, and Figure 7. A map of the injection timing TI with respect to the engine speed NB shown in , a program of the processing routine described below, etc. are stored in advance. The accelerator opening conversion value is determined to be larger than the actual accelerator opening detected by the accelerator sensor 11 and is determined to be 8 times larger than the forward accelerator opening conversion value AccF, which is used when the vehicle moves forward, and the actual accelerator opening. There are two options for reversing the vehicle. Further, the basic fuel injection amount Qo is determined based on the fuel injection amount pattern determined by the accelerator opening degree and engine rotation speed shown in FIG.

Next, a processing routine according to an embodiment of the present invention will be explained with reference to FIG. 3. - First, in step 301,
Based on the rotational speed signal SN, the engine rotational speed NE output from U and the accelerator opening Acc?c determined from the accelerator opening signal 5ACC are read.

In the next step 302, it is determined whether the 7-note switch 12 is on or not, thereby determining whether the shift lever has been shifted to the caliper range. When it is determined that the shift switch is on, in step 303, a reverse accelerator opening conversion value ACCR corresponding to the actual accelerator opening AC is calculated by interpolation from the map of accelerator opening conversion values shown in FIG. . On the other hand, when the shift switch is off, in step 304, a forward accelerator opening conversion ccF corresponding to the actual accelerator opening ACC is calculated from the map of accelerator opening conversion values shown in FIG. 4 by interpolation. .

In the next step 30, the engine speed NE read in step 301 and step 303 or step 3
Conversion value AccRt or A, Cc F calculated in 04
Using this, the basic fuel injection amount Qo is calculated using the two-dimensional interpolation method from the basic fuel injection amount map shown in Figure 6, and the basic fuel injection amount Qo is corrected using the engine coolant temperature and intake air temperature isotone. Then, calculate the fuel injection amount Qk. Here, since the converted value AccR is smaller than the actual accelerator opening ACC, the basic fuel injection amount when the vehicle is reversing is less than the basic fuel injection amount corresponding to the actual accelerator opening.
Since the converted value AccF is larger than the actual accelerator opening ACC, the basic fuel injection amount when the vehicle moves forward is increased from the basic fuel injection amount corresponding to the actual accelerator/I-opening. The accelerator opening conversion value shown in Figure 4 is
The value is approximately the same as the actual accelerator opening near 0% and 100%, and the deviation from the actual accelerator opening is maximum near 50%, so the actual accelerator opening: At around 50%, the increase/decrease from the basic rate corresponding to the actual accelerator becomes maximum.

In the next step 306, the injection timing T I corresponding to the current engine speed NE is determined from the map shown in FIG.
', (determined by the interpolation method. Then, in step 307, the first line of the spill ring 114 is set to IJ011 by controlling the first linear solenoid 117 of the Q system. At the same time, the opening degree of the timing control valve 112 is controlled based on the timing TI to control the position of the timer piston 109,
Perform fuel injection. As a result, the timing TI
Then, fuel corresponding to the fuel I\I injection amount QVc is injected.

In the above description, an example has been described in which the accelerator opening degree is prepared as a p-value, or the accelerator degree conversion value may be calculated by dividing.

According to this embodiment, the basic fuel injection amount when moving forward is increased from the basic fuel injection amount corresponding to the actual accelerator opening, and the basic fuel injection amount when reversing is increased from the basic fuel injection amount corresponding to the actual accelerator opening.・As the fuel injection amount rises and falls -'Qr,
It is possible to obtain a good feeling of acceleration in relation to the accelerator opening when the vehicle is moving forward, and to ensure safety when the vehicle is reversing.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a diesel engine equipped with a complete fuel injection system to which the present invention is applied, Fig. 2 is a block diagram showing the control circuit of Fig. 1, and Fig. 3 is an embodiment of the present invention! 11
A flowchart showing an example processing routine, Fig. 4. 1 is an h-diagram showing changes in the accelerator opening conversion value, Fig. 5 is a diagram showing an example of a fuel injection pattern, and Fig. 6 is a map of the basic fuel injection amount. The conceptual diagram No. 71Z1 is a Tm diagram showing the injection timing pattern for fuel II. 3... fbll %11 circuit, 1 accelerator sensor, 12... shift switch. Agent Tatsuyuki Unuma (and 1 other person) Figure 112, 3 1113 Figure 84 Figure 0% 100% Actor speed - 115 Figure 1 N o9 taught NE (x + 02 rpm)! 1!6 Figure 1 1 Supervision 1 Esoshiso rotation eNE (x102rpm) 7 Figure Ma OC book'l

Claims (1)

[Claims] (1) When the vehicle moves forward, the entire amount of fuel is injected based on the basic fuel injection amount determined by the accelerator opening and the engine speed, and when the vehicle moves backward, the amount of fuel is injected based on the basic fuel injection amount. A fuel injection method for diesel engines that injects fuel.