JPS63109253A - Injection amount control device for diesel engine - Google Patents

Abstract

PURPOSE:To prevent engine stall at the time of idling and enhance the starting performance in a diesel engine with injection amount control according to change of the revolving speed by increasing the amount according to the revolving speed during the period below a certain low revolving speed, and either fixing or decreasing at the time of starting. CONSTITUTION:On the basis of sensing values from an accelerator opening sensor 20, revolving speed sensor 46, suction pressure sensor 32 etc., an electronic control unit 56 controls the fuel injection amount and injection timing through an electromagnetic spill valve 50 and a timing control valve 48, respectively. That is, correction factor set greater as lower revolving speed is determined according to change in the number of revolutions to serve calculation of the spill timing. When the starter signal is on, the rotation change correction factor is fixed to a specific value (for ex. 1, 2).

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention is directed to rJA firing control technology for diesel engines.
? Regarding I+, this paper is concerned with the improvement of an injection ω control system for a diesel engine, which is particularly suitable for use in an electronically controlled diesel engine. (Prior Art) Conventionally, in order to operate a diesel engine at a predetermined rotational speed, Japanese Patent Application Laid-Open No. 17252/1983 discloses a lifting platform in which the C11 engine expansion speed is varied in an electronic full control diesel engine using an electromagnetic spill valve. An engine control method is disclosed in which the time conversion of the pitch angle is corrected by the rate of change of the rotational speed Fα, and the injection ml is corrected by decreasing ml according to the rotational speed fluctuation. However, as mentioned above, the change in rotational speed
! When the rotational speed of a diesel engine is controlled using a conventional control method that corrects for As the rate of change becomes larger, the amount of weight b5 is further reduced accordingly, which causes the engine speed to further decrease, and in the worst case, the engine may stop, which is a problem. OBJECT OF THE INVENTION The present invention has been made in view of the conventional problem 11π, and the injection ω is not reduced when the engine rotation speed is less than the idle rotation speed, thereby preventing the engine from stalling and stopping. In addition, since more fuel than necessary is not injected during startup, it is possible to prevent the generation of black smoke, and it is also possible to obtain a good dry engine and shorten the starting time.
The purpose is to provide a quantity control device.

[Means for solving problem 4 1] The present invention provides an injection fJJ m control device for a diesel engine that controls the injection amount according to the fluctuation in engine rotational speed when the engine rotational speed fluctuates. When the engine rotational speed is below a predetermined low rotational speed, the amount of injection amount 1 is increased based on the engine rotational speed, while when the engine is starting, the injection amount is fixed or decreased. , the above objective has been achieved. [Function] If the injection EAid is corrected according to the rate of change in rotational speed as in the conventional method for J3 in a two-wheel engine, if the engine rotational speed is less than the predetermined idle rotational speed, there is a risk that the engine rotational speed will further decrease. However, in order to prevent this decrease in engine speed, it is necessary to increase the dose. On the other hand, at extremely low rotation speeds at the time of starting, there is a speed range below the idle rotation speed, but in this case, the engine is rotated by the electric motor, so the rotation fluctuations do not become large as described above. Therefore, there is no need to increase the injection amount below what is necessary. Also, if the injection amount is increased more than necessary when starting the engine, it will not only cause black smoke but also cause poor startability! j There are cases. As mentioned above, when trying to prevent rotation fluctuations by controlling the amount of injection when the engine rotation speed is below the idle rotation speed, there are contradictory factors between when starting and when not starting. Therefore, it is not possible to prevent the rotational fluctuations with high accuracy. Therefore, in J5 of the present invention, when controlling the injection amount of the diesel engine, if the engine rotation speed is 1Z higher than a predetermined low rotation speed, the injection 81 is increased based on the engine rotation speed; If this is the case at startup, the sentry OA cloth is fixed or set to 1. Therefore, when the engine rotation speed decreases from a predetermined low rotation speed, the engine is injected! ) This prevents the engine from stalling and stopping the engine, and since more fuel than necessary is not consumed during startup, black smoke can be prevented and good engine speed can be achieved. start-up time can be shortened.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. In this embodiment, as shown in FIG. 2, an intake air temperature sensor 12 is provided, which is disposed downstream of the air cleaner (not shown) and is used to detect the temperature of intake air. A turbocharger 14 is provided downstream of the intake temperature sensor 12, and includes a turbine 17'lA rotated by thermal energy of exhaust gas, and a compressor 14B rotated in conjunction with the turbine 14A. . The upstream side of the turbine 14A of the turbocharger 14 and the compressor 14B
The downstream side of the valve 1 is connected to the valve 1 through a valve 15, which is a cover for preventing an excessive rise in intake pressure. In the intake air passage 16 on the downstream side of the compressor 148, an idler 81 or the like is provided to limit the flow rate of intake air.
A main intake throttle valve 18 is provided which is configured to rotate non-linearly in conjunction with an accelerator pedal 17 disposed at the driver's seat.゛The opening degree of the accelerator pedal 17 (hereinafter referred to as the accelerator distance) ACCp is the accelerator distance Hinsa 2
0 has been detected. A sub-intake throttle valve 22 is provided in parallel with the main intake throttle valve 18 , and the opening degree of the sub-intake throttle valve 22 is controlled 211 by a diaphragm device 24 . The diaphragm device 24 receives the negative pressure generated by the negative pressure pump 26.
It is supplied via a negative pressure switching valve (hereinafter referred to as SV) 28 or 3o. An intake pressure sensor 32 for detecting the pressure of intake air is provided downstream of the intake throttle valve 18.22. i゛Epil engine co-O cylinder head 10△,
An injection nozzle 34, a glow plug 36, and a flame timing sensor 38, each of which has a photoelectric beam facing the carrot combustion chamber 10B.
is provided. Further, the cylinder block 10G of the diesel engine 10 is provided with a water sensor 40 for detecting the engine cooling water temperature. Fuel is fed under pressure to the injection nozzle 34 from an injection pump 42 . The injection pump 42 includes a pump drive shaft 42A that rotates in conjunction with the rotation of the crankshaft of the diesel engine 10, and a feed pump 42B (first pump) for pressurizing fuel, which is fixed to the pump drive e@42A. (Figure 2 shows a state in which the opening is opened 90'), a fuel pressure adjustment valve 42C for adjusting the fuel supply pressure, and the pump drive shaft 42.
A reference position sensor 44 made of, for example, an electromagnetic pickup for detecting a crank angle reference position, for example, top dead center (TDC) from the rotational displacement of the pump drive pulley 42D fixed to A, and a reference position sensor 44 also fixed to the pump drive shaft 42Δ. Ta,
An engine rotation sensor 46 provided on the roller ring 42H, for example, from an electromagnetic pickup, for detecting the engine rotation speed and the position of the missing teeth from the rotational displacement of the gear 421E, which has missing teeth corresponding to the number of cylinders. and a roller ring 42 for reciprocating the face cam 42F and the plunge L42G and changing the timing thereof]-
1, a timer piston 42J for changing the rotational position of the 1'' cylinder/12H (Fig. 2 shows the state in which the cylinder is unfolded at 90°), and controlling the position of the timer piston 42J. The fuel injection ω is controlled by changing the timing of fuel release from the plunger/12G via the timing control valve (hereinafter referred to as TCV) 48 and the spill port 42K. An electromagnetic spill valve 50 for controlling, a fuel nozzle valve 52 for cutting and covering fuel, and a pilot injection OA device for controlling the fuel injection rate at the time of injection. 53, delivery pallet to prevent fuel backflow and rear molding:
//12L is provided. A glow current is supplied to the glow plug 36 via a glow relay 37. 11η intake sensor 12, accelerator rotation sensor 20,
Intake 17: T sensor 32, ignition ■4 sensor 38, water temperature sensor 7!1. o,? The J position sensor 44, the engine speed sensor 46, the glow current sensor 54 that detects the glow current flowing through the glow plug 36, the key switch, the air conditioner switch, the neutral safety switch output, the vehicle speed signal, etc. are controlled by an electronic control unit (hereinafter referred to as E
(referred to as CU) 56 and is processed by the ECLj
56, the V S V 28.30,t
) Low IJL/-37, TCV/I8, electromagnetic spill valve 5
0. The fuel cut valve 52 and the like are controlled. Further, the engine rotation speed NE is determined from No. 18 of the engine rotation speed sensor 46, and is used for the injection amount control according to this embodiment. As shown in detail in FIG. 3, the ECU 36 includes various &1
Central processing unit (hereinafter referred to as CI) for performing fEi processing
) 56A (hereinafter referred to as U) and a read-only memory (hereinafter referred to as R) for storing control programs and various data, etc.
OM) 56B and CI) U 56A (random for temporarily storing oil cylinder data etc.) 56C (hereinafter referred to as RΔ~1)
, a clock 56D that generates clock number 945, and a water temperature sensor 40 inputted through a buffer 56E.
output, the output of the intake air temperature sensor 12 which is input via the buffer 56F, the output of the intake pressure sensor 32 which is input via the buffer 56G, and the accelerator distance sensor 20 which is input via the buffer 561-1. -K MP (referred to as D converter) 56L,
Input/output capos 1 to 56M for taking in the output of the A/D converter 56L to the C, PU 56A, a starter signal inputted via the buffer 56N, an air conditioner signal inputted via the buffer 5'6P, and a buffer. CP (
Input/output capo-1 to 56S for importing into J56A,
The output of the ignition timing sensor 38 is waveform-shaped and sent to the CPU.
The waveform shaping circuit 56fl for direct input to the input interrupt port Ic, AI) 2 of the 56A, and the waveform shaping circuit 56fl for directly inputting the output of the reference position sensor 44 to the CPU 56A.
a waveform shaping circuit 56T for directly inputting the output into the same input interrupt port ICΔP2 of the CPU 56A;
U, a drive circuit 56V for driving the electromagnetic spill valve 50 according to the operation result of the CPU 56A, a drive circuit 56W for driving the TCV 48 according to the calculation result of the CPLI 56A, and the CI ) Ub
A drive circuit 56X for driving the fuel cut valve 52 according to the calculation result of 6A, and a drive circuit 56'Y for driving the pilot injection device 53 according to the IJ value of the CPU 56Δ. ', and 1) a common bus 56Z for connecting the named component devices and transferring data and instructions. Here, the ignition signal of the waveform shaping circuit 56R output is
What is input not only to the input interrupt port TCAP21 of PU56A but also to the output capo-1-56S is the waveform shaping circuit 5 which is input to the same input interrupt port ICAP2.
This is to identify the reference position of the 6T output. The operation of the embodiment can be explained at once. In this embodiment, the fuel injection amount control where a>t is executed by determining the 111% dose using a routine as shown in FIG. From NE and accelerator opening ACCp to injection amount, that is, fuel spill angleN
Gsp (°C△) is excluded. Then step 120
The spill angle ANGsp is /iI every 11°25°!
1FJj count term Cangl and remainder time Cangl
In order to separate the term θr e Il+, the quotient of the following equation (1) represents the Balza factor, the angle count term Canal, and the remainder is the inter-station count term θr e II+. 8NGsρ÷11.25°CA→Cang1 remainder θrem - (1) Next, in step 130, it is determined whether the starter signal is set to A. When the determination result is negative, that is, when Il,1 is not at the time of starting, the process proceeds to step 140, and the rotational fluctuation correction coefficient Kavt is calculated using a map such as the one shown in FIG. ) output - (proceeds to step 160. -h, when the judgment result is positive, that is, at the time of starting, the starter signal O
If N, the process proceeds to step 150, and as shown by the broken line J in FIG. 4, the rotation degree! l! IJ? The +Ii positive coefficient K avt is set to, for example, 1.2 before being fixed, and the process proceeds to step-up 160 . At step 160 and below, the time count term θre
A spill time Tsp is calculated where IIl is expressed as a time (11th place). That is, in step 160, the time
In order to perform the angle → time conversion of the term θronl, the average required engine rotation time AVT45 for J5 during 45° CA at the crank angle is multiplied by the rotational fluctuation correction coefficient K avt as shown in the following equation (2), and 4 Divide by , and store the time in the mother memory T11.25. T11.25←AVT45XKavt //I-(2)
Next, in step 170, the memory 711.25 is multiplied by the time count term θrell as shown in the following equation (3) to calculate -C spill 1.11 month TSρ -46°TSrl' -T1
1.25Xθrem --= (3) With this,
The angle→time conversion of the time count term θr e Il+ is completed. Normally, the rotational speed fluctuation of the L engine rotation speed melon becomes more noticeable at low rotational speeds, so in the above embodiment, J5 is shown in FIG. The situation is extremely tense (step 140). and,
For example, put 1.2 in the rotational fluctuation correction coefficient K avt (starting port when starter signal RON is on) and fix it (
It's il'i (Sweetsub 150). However, when the present invention is applied, the rotational fluctuation correction coefficient Kavl is not limited to a map such as the previous Lt and a value fixed at the time of starting, but other maps or other values may be used. In this case, the rotational fluctuation correction coefficient 1 (aVt is determined by, for example, excluding the engine rotational speed N), and at the time of starting, C is decreased as appropriate. In addition, in the above embodiment, the case where the present invention is applied to the injection amount control device of the J: Una diesel engine shown in FIG. It is clear that the present invention is not limited to controlled diesel engines, but can be applied to day-pillar engines having the above configuration. (Effects of the Invention) As explained above, according to the present invention, the engine rotation speed When the rotational speed decreases from a predetermined low rotational speed, the injection side elevation decreases
This prevents the engine from stopping due to stalling, eliminates unnecessary fuel injection during startup, prevents the generation of black smoke, and reduces startup time with good light distribution. You can get excellent results such as:

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the injection early control procedure of an embodiment of the 117'1 injection control D device according to the present invention, and FIG. Figure 3 is a block diagram showing the internal configuration of the electronic control unit in the injection amount control device No. 114; is a diagram showing an example of a map for deriving the injection amount correction coefficient used in the control procedure. 10...Diesel engine, 20...Accelerator speed changer, 80 Crr. ...Accelerator opening, 42...Injection pump, 44...Reference position, 46...1 engine rotation speed, NF...Engine 1 protrusion, 1 speed 1, 50... Electromagnetic spill valve, 56...Electronic control unit ('ECtJ), K av
L...Regulation law amount correction coefficient.

Claims (1)

[Claims] (1) In a diesel engine injection amount control device that controls the injection amount according to the variation in engine rotational speed when the engine rotational speed fluctuates, when the engine rotational speed is below a predetermined low rotational speed,
increasing the injection amount based on the engine rotation speed;
An injection amount control device for a diesel engine, comprising means for fixing or reducing the injection amount when the engine is started.