JPS62237058A - Injection timing control device for diesel engine - Google Patents

Abstract

PURPOSE:To enable the injection timing uneven for every injection pump to be accurately detected, by correcting the injection timing using a correction value of an injection quantity correcting means. CONSTITUTION:A phase correcting resistor 53, which corrects a tooth lack position error of an NE pulser 42E, corrects action of a plunger 42G different for every injection pump 42 and a relative position error of the NE pulser 42E. A resistance value of said resistor 53, which is selected by measuring an injection quantity in an inspection process of the injection pump 42 in its manufacturing line, is input to an ECU56. And a correction value of the injection timing is calculated by a predetermined formula by using a voltage value across both ends of said phase correcting resistor 53. This correction value corrects an injection timing advance angle, detected by the reference position of engine rotary angle detected by a reference position sensor 44 and the tooth lack position of the NE pulser 42E detected by an NE sensor 46, and unevenness of the injection timing different in every injection pump 42 is surely absorbed.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to an injection timing control device for a diesel engine, and is particularly suitable for use in an electronically controlled diesel engine. The present invention relates to an improvement of an injection timing control device for a diesel engine that controls the injection timing by detecting the advance angle of the injection timing depending on the rotational position. [Conventional technology] Conventionally, fuel injection supplied to diesel engines■
In order to precisely control
injection pump is used. This electromagnetic valve spill type distribution fuel injection pump communicates the high pressure chamber formed by the plunger tip surface and the inner wall surface of the cylinder with the low pressure chamber in the pump housing through a communication passage, and also blocks and communicates this communication passage. Fuel injection is controlled by providing a solenoid valve (referred to as an electromagnetic spill valve) and controlling the pyroelectric spill valve on and off.In other words, the plunger is lifted in the direction in which the high pressure chamber is reduced. +iff, the communication passage is shut off by an electromagnetic spill valve, and the plunger is lifted to communicate the communication passage to UL, where a predetermined amount of fuel has been injected, by means of the electromagnetic spill valve, thereby stopping fuel injection. In such a solenoid valve spill type distribution type fuel injection pump, the fuel injection timing is controlled as follows.That is, at the reference position of the engine, the reference position as shown in FIG. 7(A) is controlled. A reference position sensor that generates pulses (hereinafter referred to as TDC pulses) is installed, for example, on the drive shaft of a fuel injection pump.The position of this type of position sensor is determined by the reference position of the crank pulley when the timing light is in the idle state. The installation of the reference position sensor is adjusted by moving the position so that the output of the reference position sensor corresponds to the engine load position.Also, the output of the reference position sensor corresponds to the engine load position. A rotation speed sensor (hereinafter referred to as NE sensor) is disposed on a roller ring that is linked to the movement of the piston, and an NE pulse as a rotation angle signal as shown in Fig. 8 is attached to the drive shaft of the fuel injection pump. A gear-shaped pulse ◆8 having convex teeth 8A for generating is attached, and a missing tooth 8B is provided on the balsa 8, and the position of the missing tooth 8B that moves according to the movement of the timer position is shown in Fig. 7 (B). ), the timing T detected by the NE sensor is
TDC timing Ttd detected as the pressure feeding timing of the pump plunger and detected by the reference position sensor.
The movement j4 of the timer piston, that is, the fuel injection timing, is detected from the difference between the timer piston and c, and the timer piston is, for example, feedback-controlled. [Problems to be Solved by the Invention] Conventionally, however, the timing at which missing teeth are detected by the NE sensor has been determined by the angle at which the fuel injection pump is mounted,
Because the E balsa and NE sensor installation conditions vary greatly, it is not possible to accurately detect 111 during fuel injection, and the injection timing cannot be controlled accurately, causing the exhaust temperature and combustion chamber temperature to exceed the limit. However, there have been problems such as problems with the engine and an increase in harmful +JR gas emissions. In order to solve such problems and absorb the tooth missing detection position which varies depending on the fuel injection pump, it is possible to control the advance angle to the most retarded state under certain conditions and learn the angle in that state. Conceivable. However, when the advance angle of the fuel injection pump is controlled to the most retarded angle in this way, there is a problem that white smoke is generated in the exhaust gas of the engine. Also, in order to perform the most retarded angle control, is the fuel injection pump controlled? ! This has the problem of increasing the number of words of, for example, a microcomputer used for control, which increases cost. Also, as a technology related to the present invention, Japanese Patent Application Laid-Open No. 57-1680
In 30, electronic fuel injection detects variations in the injection amount of the fuel injection pump with an electric element, and drives and controls the actuator with the control unit to control the injection 1d in accordance with a desired standard! ) 1 unit is proposed. however,
This device also has a problem in that it cannot control variations in injection timing caused by variations in the injection pump.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and is an injection timing control Hiffi system for diesel engines that can reliably absorb variations in injection timing (time) that differ from pump to pump, and can accurately detect injection timing. 1!2. (Means for solving the 2iJ point) The present invention provides a method for determining whether or not the injection In an injection timing control device for a diesel engine that detects the timing advance h1 and controls the injection q.1:1, the main structure is shown in Fig. 1. The injection timing is determined based on the injection 04B1 correction means for correcting the injection amount which varies due to the variation in the relative position of the plunger operation from injection pump to injection pump, and the correction value of the injection part corrected by the injection amount correction means. By providing a means for correcting, the above object is achieved.

[Function I] In the present invention, when controlling the injection timing by detecting the injection timing advance amount based on the reference position of the engine rotational angle and the missing tooth position of the rotational speed parner detected by the engine rotational speed sensor, In order to correct the error in the missing tooth position of the rotational speed balsa as shown in FIG. 7, which varies from injection pump to injection pump, an injection amount correction means used for injection OA base correction is used. This injection l1i1 correction means corrects the injection date which varies due to the relative position of the plunge 1f operation (for example, lift) of the fuel injection pump and the rotational speed pulse number varying from injection pump to injection pump. Normally, the correction is performed by measuring the injection in the inspection process of the injection pump manufacturing line, and selecting and setting the correction fib of the injection 01M correction means, for example, the resistance value of the phase correction resistor. According to the present invention, the injection timing of the diesel engine is corrected using the correction value of the injection base correction means. Therefore, the injection timing that varies from injection pump to injection pump can be reliably corrected and absorbed, and the injection timing of the diesel engine can be detected with high accuracy. Therefore, let's keep an eye on the J4 season! There is no need to adjust the angle to absorb the above-mentioned variations, and it is possible to prevent problems (for example, emission of white smoke) that occur when the injection timing is controlled to the maximum angle. Embodiments Hereinafter, embodiments of an electronically controlled diesel engine for automobiles to which a fuel injection timing a-slope control device according to the present invention is applied will be described in detail with reference to the drawings. As shown in FIG. 2, this embodiment includes an intake air temperature sensor 12 disposed downstream of the air cleaner 11 for detecting the temperature of intake air. Downstream of the intake temperature sensor 12 are a turbine 14Δ rotated by the thermal energy of exhaust gas, and a turbine 14A.
A turbocharger 14 consisting of a compressor 14B rotated in conjunction with the engine is provided. The upstream side of the turbine 14A of the turbocharger 14 and the compressor 14B
The downstream side thereof is communicated with each other via a wastegate valve 15 for preventing an excessive rise in intake pressure. In the venturi 1G downstream of the compressor 14B,
'aFI1. of intake air at idle. 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 to limit the amount of air to υ1. The opening degree of the accelerator pedal 17 (hereinafter referred to as
ACCp (referred to as accelerator opening degree) is the accelerator sensor 2
0 has been detected. A sub-intake proof 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 by a diaphragm device 24. Negative pressure generated by a negative pressure pump (not shown) is supplied to the diaphragm device 24 via a negative pressure switching valve (hereinafter referred to as vSv) 28 or 30. An intake pressure sensor 32 for detecting the pressure of intake air is provided downstream of the intake throttle valve 18.22. In the cylinder head 10A of the diesel engine 10,
An injection nozzle 34 and a glow plug 36 are provided, the tips of which face the engine combustion chamber 10B. or,
The cylinder block 10G of the diesel engine 10 is equipped with a water temperature sensor 40 for detecting 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 drive shaft 42A that rotates in conjunction with the rotation of the crankshaft of the diesel engine 10, and a feed pump 42B (see FIG. 2) for pressurizing fuel contained in the drive shaft 42A. 90" shows the expanded state), the fuel pressure F14 regulating valve 42C for regulating the fuel supply pressure W4, and the rotational displacement of the gear 42D fixed to the drive shaft 42A to determine the reference position of the engine, for example, top dead center. (TDC), a reference position sensor 44 consisting of an electromagnetic pickup, for example, an adjustment resistor 45 for electrically adjusting the positional deviation, and an adjustment resistor 45 for electrically adjusting the positional deviation. An NE sensor 46 is mounted on the rear roller ring 42H in order to detect the engine rotation angle and the position of missing teeth from the rotational displacement of the NE balsa 42E, which is fixed to the shaft 42A and has the shape shown in FIG. 8 above.
, a roller ring 421-1 for reciprocating the face cam 42F and the plunger 42G and changing the timing thereof, and a timer piston 42J for changing the rotational position of the roller ring 42H (Fig. 2). is 90°
), a timing control valve (hereinafter referred to as TCV) 48 for controlling the injection timing by controlling the position of the timer piston 42J, and fuel from the plunger 42G via the spill boat 42K. An electromagnetic spill valve 50 for controlling the amount of fuel injection by changing the release timing, a fuel cut valve (hereinafter referred to as FCV) 52 for cutting fuel in the event of an abnormality, and a fuel cut valve (FCV) 52 for preventing fuel backflow and after-moulding. A delivery valve 42L for preventing this is provided. Here, 53 in the figure is a phase correction resistor for correcting errors in the operation (lift) of the plunger 42G and the relative position of the NE pulser 42rE, which differ for each injection pump 42. This phase correction resistor 53 corrects the error in the tooth-missing position of the NE pulse shown in the above-mentioned diagram q57, and corrects the error in the relative position. Further, the resistance value is selected by measuring the injection amount in an inspection process in the production line of the injection pump 42. Intake temperature sensor 12, accelerator sensor 20, intake pressure sensor 32, ignition +111 sensor 38, water temperature sensor 40, parking position sensor 44, adjustment resistor 45, NE sensor 46, phase correction resistor 53, key switch, air conditioner The switch, neutral safety switch output, vehicle speed signal, etc. are controlled by an electronic control unit (hereinafter referred to as ECU) 56.
is input and processed, and by the output of the ECU 36,
The vS28.30XTCV48, ttHJi spill valve 50, and FCV52 cap are controlled. The ECU 36, as shown in detail in FIG.
A central processing unit (hereinafter referred to as CPU) 56A for processing, the output of the water temperature sensor 40 inputted via a buffer 56B, the output of the intake temperature sensor 12 inputted via a buffer 56G, and a buffer 56D. The output of the 11θ1:2 intake pressure sensor 32 is input via the accelerator sensor 20, which is input via the buffer 56E.
A multiplexer (hereinafter referred to as MPX) for sequentially receiving the output, a phase correction resistance voltage signal based on the voltage across the phase correction resistor 53 input via the buffer 56F, a τ correction voltage signal input via the buffer 56G, etc. Name>
561-1, and an analog-to-digital converter (hereinafter referred to as A/D') for converting the analog signal output from the M P
a#i'Lli) 56J,! :, a waveform shaping circuit 56 for shaping the waveform of the output of the N Et sensor 46 and inputting it into the CPU 56A, and a waveform shaping circuit 56L for shaping the waveform of the output of the U heavy position sensor 44 and inputting it to the CPU 56A. , a buffer 56N for taking the starter signal into the CPU 56A, a buffer 56P for taking the air conditioner signal into the CPU 56A, and a buffer 56P for taking the torque converter signal into the CPU 56A.
A buffer 56Q for importing into A, and the CPLJ 56
a drive circuit 56R for driving the FCV 52 according to the calculation result of A; a drive circuit 568 for driving the TCV 48 according to the calculation result of the CPU 56A;
A drive circuit 56T for driving the electromagnetic spill valve 50 according to the calculation result of CP and tJ56A, and a drive circuit 56T for detecting the current flowing through the electromagnetic spill valve 50.
A current detection circuit 56U for feeding back to the CPtJ 6T, a low voltage detection circuit 56V for detecting low voltage and inputting it to the drive circuit 56T, and the CPtJ 56A.
A drive circuit 56W for outputting a self-diagnosis signal (hereinafter referred to as a diagnosis signal) according to the one-bit result, and the CP
It is composed of a drive circuit 56X for driving a warning light according to the calculation result of LI 56A. Here, the phase correction resistance voltage signal is a signal based on the voltage value across the zero correction resistor 530, and is taken into the CPU 56A for correction of the injection timing. is a signal for correcting the deviation in responsiveness due to individual differences in each component in the injection pump 42. The operation of an actual factory example will be explained below. The injection timing control in this example is shown in FIG. The routine is executed according to the flowchart shown in FIG.
There is a main (MAIN) routine shown in B) that calculates the injection timing correction value Gca. That is, in the TCAP routine, it waits until a pulse is input, and when the pulse is input, it first performs step 1.
At step 10, it is determined whether the pulse input to the ECU 36 is the NE pulse or the TDC<tiling position) pulse. If the determination result is positive, that is, the input pulse is an NE pulse, the process proceeds to step 120, where it is determined whether it is the OS-th NE pulse (NE pulse No., 0) as shown in FIG. 5, for example. If the judgment result is positive, proceed to step 130,
As shown in the following equation (1), the current interrupt time TINT is calculated by calculating the interrupt time rLINTl 180"CA before by crank angle, minus T180'CAf: The time spent T180 is stored. T180←TrNT-Tl-INT... (1) Next, in step 140, the current interrupt time TINT is substituted into the interrupt time TLINT and stored. On the other hand, if the determination result in step 120 is No, and the struck NE pulse is not No. 6○, the process proceeds to step 150; The input NE pulse is the second NE pulse (NE pulse N0
．． 2). When the full constant Wi result is positive, the process proceeds to step 160, and the current interrupt time TINT is substituted for the input time TCAIN of the NE pulse N002. On the other hand, if the determination result in the previous step 110 is negative, and the struck input pulse is not an NE pulse but a TDC pulse, the process advances to step 170, and from the current input time TINT to the N
The pulse interval 1-ca is calculated by subtracting the input time TCAIN of E pulse N0.2 as shown in the following equation (2). Tea・−TINT−TCATN=(2) Once the pulse interval Tca is obtained in this way, this routine is finished, and when step 140 and step 160 are finished, and if the judgment result in step 150 is negative, In this case, this routine is terminated and waits until an interrupt is input. Next, in the MAIN routine, first step 18
0, the pulse interval TCa calculated by ICAP Luzhin
is calculated as in the following equation (3) and changed from time to angle,
Find the angular pulse interval ACTea. △CTca←180XTca/18O-(3) Then,
In step 190, the voltage value V across the phase correction resistor 53 is determined.
RP is detected and analog-to-digital converted value <A/
DI Direct> and enter it. Next, in step 200, the following equation (4) is calculated using the voltage value \'RP to calculate a correction value GCΔ for the injection timing. GC△←1.125X (V RP -2,5)...
(4) This formula (4) is a formula that calculates the correction value GCA from the voltage value VRP based on the relationship LL shown in FIG. 6. In the example, the range of the correction value GCA is ,
The voltage value VRP is in the range of 0 to 5 (v). Moreover, the example shown in the figure is just an example, and a pond relationship can also be used. In that case, it is obvious that this equation (4) will also take a different form. Next, the process proceeds to step 210, where this correction 1lff is calculated from the pulse interval ACTea that was angle-converted in the previous step 18O.
The corrected pulse interval ACTea is calculated by subtracting GC8 as shown in the following equation (5). ACTea=ACTca-GCA・・・・・・・・・
15) The relationship between each pulse in this case is as shown in FIG. 5, and the start timing of the pulse interval ACTCa can be set to the designed median value of the NE pulse No.2. As shown in the figure, by reflecting the pulse interval Ac'rca in the injection timing, the variation for each injection pump 42 is reduced by 1.
) Note: NE sensor 46 and NE balsa 42E f=I
G: An error in the injection timing due to the J error can be corrected without any control using the most retarded angle learning or the like. Incidentally, in the above embodiment, a phase correction resistor was illustrated as the emission darkness correction means, but the injection IJJ fi according to the present invention
The t correction means is not limited to this, and a pond means may also be used. Further, in the embodiment, the correction value GC based on the voltage value of the phase correction resistor 53 is determined by the relationship shown in FIG.
A was calculated, but the relationship for calculating the correction value is the 6th one.
It is clear that the relationship is not limited to that shown in the figure, and that other relationships can be used. Furthermore, in the embodiment described above, the injection timing is corrected by the ECIJ56, which is controlled according to the flowchart shown in FIG. 4, but the means for correcting the injection timing according to the present invention It is clear that the present invention is not limited to controlled IT devices, but can be applied to injection timing control devices having other control procedures. Further, in the above embodiment, the present invention was applied to injection timing control of an automobile diesel engine equipped with an electromagnetic spill valve, but the scope of application of the present invention is not limited thereto, and may be applied to other types of fuel. It is clear that it is equally applicable to diesel engines with injection pumps. Effects of the Invention 1 As described above, according to the present invention, it is possible to reliably correct the injection timing that varies from injection pump to injection pump, and it is possible to accurately detect the injection timing of a diesel engine. Therefore,
Under certain conditions, such as when idling or decelerating, it is possible to absorb variations in the injection OA timing without setting it to the most retarded position, so it is possible to absorb problems that occur when the injection timing is set to the most retarded position, such as white; It is possible to prevent the occurrence of t. Since the control itself can be simplified, for example, a microcomputer can be used to
When controlling rJ1, the number of memory words used for the control can be reduced, and it is possible to correct variations in injection timing without increasing costs. Furthermore, when performing the most retarded angle learning, the injection timing is affected by the initial setting of the injection pump, so in the past it was necessary to make the initial setting accurately, but with the present invention, it is possible to feed back variations in this initial setting. This has excellent effects such as simplifying the initial setting of the J3 injection pump when assembling the engine.

[Brief explanation of drawings]

FIG. 1 is a block diagram that does not show the gist of the present invention, and FIG. 2 is a sectional view, including a partial block diagram, showing the overall configuration of an embodiment of an automotive diesel engine in which the present invention is adopted. , FIG. 3 is a block diagram showing the configuration of the electronic control unit used in the above embodiment, and FIG. 4 <A), (B
) is a flowchart showing a routine for controlling the injection timing, FIG. 5 is a diagram showing an example of the relationship between the reference position pulse and the NE pulse, and FIG. 6 is a diagram showing the voltage value of the phase correction resistor and correction. FIG. 7 is a diagram showing an example of the relationship between TDC pulses and NE pulses, and FIG. 8 is a plan view showing an example of the shape of NE parna. 'IO...Diesel engine, 20...Accelerator sensor, 34...Fuel injection Q1 nozzle, 42...Fuel injection pump, 42D...Gear, 42E...NE balsa, 42G...・Plunger, 42J...Timer piston, 44...L (semi-position sensor, 46...NE sensor, 48...Timing control valve (TCV), 50...Electromagnetic spill valve, 53... Phase correction resistor, 5G...° multiplex control unit (ECU).

Claims (1)

[Claims] (1) Based on the reference position of the engine rotation angle and the rotation speed pulsar missing tooth position detected by the engine rotation speed sensor,
In a diesel engine injection timing control device that detects the injection timing advance amount and controls the injection timing, the injection amount varies due to variations in the relative positions of the rotational speed pulsar and the injection pump plunger for each injection pump. and means for correcting the injection timing based on the correction value of the injection amount corrected by the injection amount correction means. Control device.