JPS59176619A - Detecting method of rotation position of engine - Google Patents

Abstract

PURPOSE:To detect an engine rotation position accurately by detecting the reference position time and specific rotary displacement time of engine rotation from rotations of a crank shaft, etc., and the driving shaft of a fuel injection pump, and deciding the engine rotation position. CONSTITUTION:The rotation of a cam shaft or crank shaft 10A is detected, and the reference position time when the engine rotates to the reference position is detected by a top dead point sensor 5 and applied to a control unit 62. On the other hand, the rotation of the driving shaft 14 of the fuel injection pump 12 is detected and the specific rotary displacement time of the engine is detected by an engine rotatin sensor 22 and applied to the unit 62. Then, the unit 62 calculates decides on the engine rotation position at the rotary displacement time on the basis of the difference between both detection times. Thus, the attachment of each sensor is facilitated and adjustments in attachment are unnecessary, thereby detecting accurately the engine rotation position for determining the timing of ignition, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting engine rotational position, and in particular,
The present invention relates to an engine rotational position detection method suitable for use in an automobile diesel engine equipped with an electronically controlled i11 type fuel injection pump.

In recent years, the ignition timing has been changed to electronic 1lI depending on the engine operating condition.
An automobile gasoline engine equipped with an ignition timing control IA device that controls the ignition timing, and an automobile diesel engine equipped with an electronically controlled fuel injection pump that electronically controls the fuel injection timing according to the engine operating condition. The engine has been put into practical use. In all such electronic fill-fill engines, the ignition timing or fuel injection timing is controlled according to the engine rotational position, that is, the crank angle, and it is extremely difficult to know the crank angle accurately. is important.

Therefore, conventionally, for example, in a six-cylinder Kallin engine, the cylinder discrimination pulse G (first
Cylinder discrimination sensor that generates the figure (see A>) and engine rotation pulses NEo, NE+ every 30 degrees of crank angle.
, NE2- (see Figure 1 (B)) is installed inside the distributor which has a test regulator shaft that rotates in conjunction with the (rotation) rotation of the engine crankshaft. n by the cylinder discrimination pulse G.
0 Engine rotation pulse NEo, NET, N22...
After determining which of the two points is the target detection position of each cylinder, for example, the top dead center, and performing waveform shaping twice, select the top dead center, assuming that the falling edge will be the top dead center of each cylinder. I would like to determine the ignition timing, etc. based on the dead center position and each engine rotation signal, and control it (see Figure 1 (C) and (D)).
. However, in general, in a gasoline engine in which both sensors are built into the test refuter, once the tip of the test refuter shaft is inserted into the engine, the actual detection position θa detected by the engine rotation sensor or the engine It does not match the target detection position θO (for example, top dead center), and between the two, there is a jetting θ1 due to positional deviation or component variation. It was necessary to adjust the sensor position by loosening the set screw on the refuter and rotating the housing of the test refuter while the engine was running.

However, in this case, the sensor position must be adjusted near the rotating body, which is very dangerous.

In addition, in the case of a T-cell engine, it may be easy to install the engine rotation sensor inside the fuel injection pump, but it is impossible to adjust it by loosening the set screw of the fuel injection pump while the engine is running. However, there was a problem in that accurate position adjustment was extremely difficult.

Therefore, it is not possible to exactly match the actual detection position detected by the engine rotation sensor with the target detection position, such as top dead center, and the ignition timing, fuel injection timing, etc. There is a problem that the control may not be able to be performed accurately.

In addition, it may be possible to detect the fuel timing etc. only from the top dead center signal and perform fee 1-hack control.Since the engine rotational change NJ within one engine revolution is large, there is a risk of incorrect cutting. be.

Further, as related to the present invention, for example, Japanese Patent Application Laid-open No. 1983-
As shown in No. 8328, there has been proposed a method for injecting fuel by determining a cylinder to inject fuel according to an engine rotation signal, a top dead center signal, and cylinder discrimination. It was not intended to determine the exact engine rotational position.

The present invention has been made in order to solve the problems of the prior art as described above, and it is possible to determine the accurate engine rotational position without adjusting the position of the engine rotation sensor. It is an object of the present invention to provide an engine rotation position detection method that can accurately control WJ and the like.

The present invention provides an engine rotation position detection method, as summarized in FIG. 2, which includes a procedure for detecting the reference position time at which the engine rotation position becomes the reference position from the rotation of the crankshaft or camshaft; A procedure for detecting the rotational displacement time at which the engine rotational position has changed by a predetermined rotational angle from the rotation of the pump drive shaft, and an accurate measurement at each rotational displacement time according to the difference between the reference position time and the rotational displacement time. The above object is achieved by including a procedure for determining a proper engine rotational position.

According to the present invention, it is not necessary to accurately position the engine rotation sensor for detecting rotational displacement 91j, and therefore, it is possible to accurately detect the engine rotational position without making difficult position adjustments. can. Furthermore, if a reference position sensor for detecting the reference position, such as a top dead center sensor, is provided on the crankshaft, detection errors due to elongation of the timing chain or timing/belt, etc. can be corrected.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a four-cylinder diesel engine for automobiles equipped with an electronically controlled fuel injection pump and employing the engine rotational position detection method according to the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 3, this embodiment includes a drive shaft 14 that rotates in conjunction with the rotation of the crankshaft 10A of the diesel engine 10, and a feed pump fixed to the drive shaft 14 for pumping fuel. 16 (Figure 3 does not show the 90° unfolded state), a fuel pressure adjustment valve 18 for adjusting the fuel supply pressure, and a crank angle of the diesel engine 10 from the rotational displacement of the drive shaft 14. an engine rotation sensor 22 consisting of, for example, an electromagnetic pickup capable of detecting the rotational displacement time when the engine has rotated by a predetermined rotation angle, for example 30'CA; a roller ring 24 for controlling fuel injection timing; and a roller ring 24 for driving the roller link 24. a timer piston 26 for controlling the position of the timer piston 26; and a timing control valve 2 for controlling the position of the timer piston 26.
8. A timer position sensor 30 for adjusting the position of the timer piston 26, such as a variable inductance sensor; a spill ring 32 for controlling fuel sniffing; and a spill ring 32 for driving the spill ring 32. , a spill actuator 34 consisting of a plunger 34A, a compression spring 34B, a coil 34C and a coil case 34D, and a spill position consisting of, for example, a variable inductance sensor 1) for detecting the position of the spill ring 32 from the displacement of the plunger 34A. A fuel injection pump 12 having a sensor 36, a fuel cut solenoid (hereinafter referred to as FCV) 38 for cutting fuel when the engine is stopped, a plunger 40, and a delivery valve 42; and a fuel injection pump 12 that is discharged from the delivery valve 42 of the fuel injection pump 12. Detects the pressure of the intake air taken in through the injection nostle 44 and the intake pipe 46 for injecting ffi 1+ into the sub-combustion chamber of the diesel engine 10.
the intake pressure sensor 48 and the diesel engine 1
0 cylinder block 10B for detecting the engine cooling water temperature and the depression angle (1
The accelerator sensor 56 detects the rotational state of the crankshaft 10A, and detects the engine rotational position or the reference position, for example, the top dead center when the engine reaches the reference position, for example, the top dead center. A top dead center sensor 58 that outputs a signal; and a pressure sensor 6 that detects the fuel pressure of the plunger 40A in the fuel injection pump 12 and outputs an injection pressure signal.
0, the accelerator opening degree detected from the output of the accelerator sensor 56, the engine rotation speed detected from the output of the engine rotation sensor 22, the engine cooling water temperature informed by the output of the water temperature sensor 52, etc. Determine the amount of fuel injected from the fuel injection pump 12 to the amount of fuel injected into the fuel injection pump 12.
Timing control valve 28, spill actuator 3
It is composed of an electronic control unit (hereinafter referred to as ECU) 62 that controls the 4th unit, etc.

As shown in the figure, 25 is the cam play 1 to 33 is the tension spring.

As shown in detail in FIG. 4, the Ctj 62 is a central processing unit [~ (hereinafter referred to as CPU) 62A, for example, a microprocessor, for performing various arithmetic operations.
A clock circuit 62B that generates each i-clock signal, and a random knock access memory including a hack-up random access memory for temporarily storing the count data (in the CPU 62A) and for backup in the event of a power failure. A memory (hereinafter referred to as RA~1) 62C, an only memory (hereinafter referred to as ROM) 62D that stores various data, etc., and the water temperature inputted through a buffer 62E. sensor 52
Output, output of the intake air sensor 48 inputted via the buffer 62F, output of the accelerator sensor 56 inputted via the buffer 62G, sensor, drive circuit 62
The output of the spill position sensor 36 is driven by a frequency signal for driving the sensor of H output and is input via the sensor 1 word detection circuit 62I, and the frequency signal for driving the sensor of the sensor driving circuit 62J is driven by the sensor signal ? for sequentially taking in the output of the timer position sensor 30 etc. input via the detection circuit 62K? Lutibrexa 6
2L, an analog-to-digital converter (hereinafter referred to as △D converter) 62 [\1, and the output of the A, ,'D converter 62M for converting the analog signal output from the multiplexer 62L into a digital signal. The input/output capotrometer 2N for importing the data into the CPU 62A, the upper Tahi point sensor 58, the engine rotation sensor 22, and the 1ljs ijJ pressure sensor 6
an input interface 620 for waveform shaping the output of CI-'U62A and importing it into the CPU62A;
A driving circuit 62P for driving the timing control valve 28, and a driving circuit 62Q for driving the FCs to 738 according to the calculation result in the CPU 62A.
and said C1 converted into an analog signal by a digital-to-analog converter (hereinafter referred to as the 'A converter) 62R.
- A servo amplifier 62S and a drive circuit 62T that drive the Subil actuator 34 according to the difference between the Jj62A output and the Schill position sensor 36 output, and a common hub 62 that connects the respective component devices. Shito, 7:
It is composed of lY et al.

The action will be explained below.

In this embodiment, the top dead center time detected by the top dead center sensor 58 and the engine rotation sensor 22
The calculation of -4U of the crank angle during the rotational displacement time detected at is executed during engine operation by an interrupt routine based on a top dead center signal or an engine rotation signal as shown in FIG.

That is, when the top dead center point ii or l of the output of the upper shift point sensor 58 occurs, the routine shown in FIG. 5 above is executed. Step 110 is entered, and it is determined whether the current interruption is an interruption by the Doi-A 1M. If the determination result is positive, the process proceeds to step 112, where the current time is stored in the memory A as the base 4 position time, and this routine is exited.

- 10,000, if the judgment result in step 110 is negative, that is, if it is judged that it is the current cutting or the interruption due to the engine rotation signal, the process proceeds to step 114, and the current interruption or top dead center It is determined whether the interrupt is caused by the engine rotation signal following the signal. If the determination result is negative, the process proceeds to step 116, where the current time is stored in the memory B as the rotational displacement time, and this routine is terminated.

On the other hand, if the judgment result in step 114 is positive, the process proceeds to step 118, and the current time is set to top dead center 1^.
@Record in memory C as the rotation degree IM time immediately after! ?
do. Next, proceed to Stella 1] 20, and from the difference between the time recorded in memory C and the time stored in memory A, it is determined that the engine rotation rate is 1 time immediately after the top dead center signal is generated. Calculate the time difference of 1.2 until the signal occurs. Next, the process proceeds to step 122, where the time stored in memory C and this memory C are stored. : The time t required to rotate the crank at a predetermined angle, for example, 30 degrees, including top dead center from memory B (difference between 7 and 7") just before.
Calculate 1. Next, the process proceeds to step 124, and the angular deviation α from the top dead center signal to the engine rotation signal immediately after the top dead center is calculated using the following equation.

α-(12,'L+)X30'...(1)
Depending on the angle difference α obtained in this way, whether it is the positive b1 or rank angle of each engine rotation No. 18, for example, AT
DCcv', ATDC(30 α')', A1
− D C (60 Cv >'...) can be determined.

Detection of engine parameters, such as fuel injection timing, in accordance with the accurate engine rotational position determined in this manner is performed, for example, as shown in FIG. 6. That is,
First, in step 210, the time difference 3 from the fuel injection side pressure detected by the injection pressure sensor 60 to the next engine rotational position signal, for example N22, is determined (see FIG. 7).

Next, the process proceeds to step 212, where the engine rotation signal N1=
The time difference t4 required from s to N22 is determined.

Next, the process proceeds to step 214, and the crank angle CA3 at the time when the fuel injection signal T is generated (from 0 to the engine rotation signal N) is determined using the following equation.

CA 3 = (r 3 (a)
x3 0" ・ ・ ・ (2) On the other hand, the position of the engine rotation signal NEG is determined by using the flowchart shown in FIG. From the time E2 from TL) C to the engine rotation signal NE+, α' (-(L2
[+)
The solution is to exclude t by the following equation.

C, At=C30'-α'-CA3 E B rD
c... <3> An example of the relationship between the top dead center one word, the engine rotation signal, and the fuel injection stiffness signal in this embodiment is shown in the seventh example.

In this way, the accurate Sy1 fuel injection timing C
The ECU 62 injects 14tl at the time of fuel injection so that the difference between At and the preset 4114 timing is O.
b1 Feedback control is performed.

In this embodiment, since the top dead center sensor is provided on the crankshaft, it is possible to correct an incorrect angle due to stretching of the timing chain or timing belt.

Incidentally, the above embodiments describe the present invention as a fuel for an automatic Ichikawa diesel engine! Although the present invention is applied to detecting the timing of the sword, the scope of the present invention is not limited thereto, and may be used to detect other parameters of an automobile tasel engine.
Alternatively, it can also be used to detect engine parameters of a Kallin engine.

As explained above, according to the present invention, it is possible to determine the accurate engine rotational position without adjusting the position of the crank angle sensor, and therefore it is possible to accurately control ignition timing, fuel injection timing, etc. becomes. Furthermore, since the four-position sensor such as the top dead center sensor and the engine rotation sensor can be mounted on separate rotation shafts, there is an advantage that the arrangement of each sensor is easy.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the difference between the actual detection position of the crank angle sensor and the eye (slip detection position) for explaining the present invention in detail, and FIG. 3 is a flowchart showing the gist of the present invention, and includes a partial Norlock diagram showing the configuration of the first actual example of the electronically controlled iM1 fuel injection system for a four-cylinder automotive vehicle, which is adopted according to the present invention. A cross-sectional view, FIG. 4 is a block diagram showing the configuration of the electronic control unit used in the above embodiment, and FIG.
Similarly, the angle leakage axis α between the reference position time and rotational displacement time
FIG. 6 is a flowchart showing an interrupt routine using a top dead center signal or an engine rotation signal for determining the k-th point, and FIG. 6 similarly shows a routine for determining the fuel injection timing. I flowchart, FIG. 7 is a one-line diagram showing an example of the relationship among the top dead center signal, engine rotation (No. 8), and fuel injection (No. 8) in the above embodiment. 10... Tea cell engine, 10A ... Crankshaft, 12 ... Fuel injection ponno, -14 ... Drive shaft, 20 ... Gear, 22 ... Engine rotation sensor, 40 ... Plunge) 7. 40A ... Plunge V To, b8...Top dead center sensor, 60...Injection pressure sensor, 62...-Child control unit (ECU). Agent: Ron Takaya (and 1 other person) Fig. 4 Fig. 5

Claims (1)

[Claims] (1) A procedure for detecting the reference position time at which the engine rotational position became the reference position from the rotation of the crankshaft or camshaft, and a procedure for detecting the reference position time when the engine rotational position became the reference position from the rotation of the fuel injection pump drive shaft. An engine rotational position detection method comprising: a step of detecting a rotational displacement time; and a step of determining an accurate engine rotational position at each rotational displacement time according to the difference between the reference position time and the rotational displacement time. .