JPH01267360A - Ignition timing control device - Google Patents

Abstract

PURPOSE:To improve statability in any case, by a method wherein, during cold starting of an engine, ignition is effected on the delay side being the second pulse of a pulse group classified by a cylinder, and during restarting after completion of warming-up, ignition is made on the advance side being a first pulse. CONSTITUTION:During running of an engine, based on an output from a crank angle sensor 3, the number of revolutions of an engine is calculated by a number of revolutions of engine calculating means 23. The calculated number of revolutions of an engine is compared with the given number of revolutions by an ignition selecting means 26 to decide whether an engine is in a starting state or not. When decision of the starting is made, it is decided by a water temperature deciding means 21, to which an output from a water temperature sensor 8 is inputted, whether an engine is in a cold state. When it is decided that an engine is in a cold state, a second cam pulse of a cam pulse group from a cam angle sensor 6 is divided by a dividing means 24 to input a result to an ignition pulse generating means 27. Meanwhile, when an engine is in a restarting state after completion of warming-up, a first cam pulse is divided to input it to the generating means 27 to perform control of ignition.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an ignition timing control device for an automobile engine, and more particularly to an ignition timing control device that detects a cam angle or a crank angle from a reference position to set the ignition timing.

[Conventional technology]

Conventionally, as this type of time control type ignition timing control device, there has been one as shown in, for example, Japanese Patent Laid-Open No. 120918/1983. The above-mentioned ignition timing control device has a large number of teeth formed on the outer periphery for generating a crank angle signal, and a predetermined one of the teeth.
A crank angle detector is composed of a rotating body with a magnetized material embedded in each tooth to serve as teeth for generating a reference position signal, and a pickup installed at a position facing the teeth of this rotating body, reducing the number of parts. In addition to reducing costs, the crank angle resolution is improved by converting and generating crank angle (unit angle) signals by dividing the time of a specific number of teeth, and improving the accuracy of time-controlled ignition timing control. This is what I did. However, with this method, since the engine speed is low when the engine starts, the ignition timing from the reference pulse signal position is long, and the engine speed fluctuates widely even within one cycle, resulting in variations in ignition timing. It was not possible to start smoothly. Therefore, the applicant in this case previously applied for patent application No. 62-21597.
We are proposing something like the one shown in No. 8. In this time-controlled ignition timing control device, a cam pulse signal from a cam angle sensor is used to calculate the crank angle, such as top dead center (TDC).
), calculate the cycle which is crank angular velocity information between crank pulses where no cam pulse is detected, and convert this to the time from the crank pulse (reference signal) at the end of the above cycle to ignite. In addition to determining the time and igniting, when starting the engine when the engine speed is unstable, an ignition signal is output based on the cam pulse, which has less fluctuation in the cam angle, to reduce ignition timing fluctuations at engine startup, and This allows for smooth starting.

[Problem to be solved by the invention]

By the way, in the technique described in Japanese Patent Application No. 62-215978 as mentioned above, ignition is performed in response to cam pulses, so variations in ignition timing are eliminated and starting performance is good in that sense. However, since the ignition timing when starting the engine is uniquely set, starting performance may not be good depending on the operating condition of the engine.For example, if the cam pulse position is set to the retarded side, the engine will warm up. When restarting the engine, starting performance deteriorates. Furthermore, if the cam pulse is set to the advance side, the startability of the engine deteriorates when the engine is cold, especially in winter or in cold regions. In this way, in any of the above cases! & There was a problem that the cam pulse position had to be set at an unsuitable intermediate position. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an ignition timing control device that allows the engine to start smoothly in any engine condition.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cylinder discrimination sensor that detects a plurality of cam angles for each cylinder and outputs a group of cylinder discrimination pulses each consisting of at least two pulses; It consists of a crank angle sensor that detects the angle and outputs crank pulses A and B, and a control unit that inputs pulse signals from each of the above sensors to time-control the ignition timing, and the control unit includes:
An engine rotation speed calculation means for calculating the engine rotation speed using the crank pulses A and B, an ignition timing calculation means for calculating the ignition timing from the engine rotation speed and the engine load, and a timer for converting the calculated ignition timing into an ignition time. means, a water temperature determining means for determining the state of the engine at the time of starting based on the engine cooling water temperature, and a cylinder discriminating pulse of the first or second note of the cylinder discriminating pulse group according to the determined engine state. A frequency dividing means that divides the frequency, an ignition pulse generation means that generates an ignition pulse (ignition time) in synchronization with the frequency-divided cylinder discrimination pulse, and a and ignition selection means for determining whether the engine is in operation and selecting either the ignition time by the ignition pulse generation means or the ignition time by the timer means, and the determination of the engine state is made at the time of restart after completion of warm-up. If it is determined that the first cylinder discrimination pulse is on the advance side of the group of cylinder discrimination pulses, the frequency dividing means divides the first cylinder discrimination pulse on the advance side of the group of cylinder discrimination pulses, and when it is judged that it is a cold start, the first cylinder discrimination pulse is on the retard side. The cylinder discrimination pulse of a certain second note is frequency-divided, and an ignition pulse synchronized therewith is outputted from the ignition pulse generation means.

[For production]

Based on the above configuration, during normal operation, ignition timing control using a time control method is performed based on the ignition timing calculated by the ignition timing calculating means according to the operating state. On the other hand, when the engine start time is determined based on the engine speed, the ignition selection means selects the ignition time from the ignition pulse generation means,
When starting the engine cold, ignition is performed on the retard side, which is the second note of the cylinder discrimination pulse group, and when the engine is restarted after warming up, it is ignited on the advance side, which is the first note. The engine can be started successfully even in the following engine conditions.

【Example】

The first embodiment of the present invention will be described below with reference to FIGS. 1 to 6.
The second embodiment will be explained with reference to FIG. 7, and the third embodiment will be explained with reference to FIGS. 8 to 10, respectively. [First Embodiment] In FIG. 1, the engine crankshaft 1 includes:
A crank rotor 2 for detecting the crank angle position is attached, and four protrusions 2a, 2b, 2c, 2d are provided on the periphery of the crank rotor 2, for example, to generate a pulse at a predetermined crank angle position. Protrusion 2a
, 2c is 112゛ in front of TDC, and protrusions 2b, 2d
are arranged 80° in front of TDC, and detect these and generate crank pulses A (protrusions 2a, 2c), respectively. A crank angle sensor 3 that generates a crank pulse B (protrusions 2b, 2d) is disposed facing each other. On the other hand, a cam rotor 5 for detecting the cam angle position is attached to the camshaft 4, which rotates once for every two revolutions of the crankshaft 1. On the periphery of the cam rotor 5, cylinder discrimination is performed at a predetermined angular position of the cam angle. The protrusion groups 5a, 5b, and 5c do not generate pulse groups. 5d is the number of cylinders plus 1 depending on the ignition order (
5a1-5a2, 5b1-5b4, 5c1-5c3
, 5d1 to 5d5) are arranged at 90° intervals, and the above crank angle pulse is divided into two types of crank pulses A, 5d1 to 5d5).
The four protrusions 5a1 and 5b1 are used to generate a cam pulse as the first cylinder discrimination pulse, which serves as a reference signal when the four engines are started after completion of engine B.
, 5c1, and 5dl, for example, at 5 degrees before TDC, and four protrusions 5a2, 5b2 in order to generate a second-order cam pulse that becomes a reference signal during a cold start. 5C2 and 5d2 are set at TDC, for example, and the following protrusions are set at every 5 degrees, and a cam angle sensor 6 as an air amount determination sensor is disposed opposite to this cam rotor 5. The above crank rotor 2. The arrangement of each protrusion on the cam rotor 5 is shown in FIG. The pulse signal from the cam angle sensor 6 as a cylinder discrimination sensor is the fourth
A suction pipe pressure sensor 7 detects the suction pipe pressure that occurs at the timing shown in the figure and is an example of engine load.
The temperature is input to a control unit 10 consisting of a microcomputer that controls the ignition timing together with a cooling water temperature sensor 8 that detects the engine cooling water temperature. Then, the control unit 10 calculates the ignition time according to a predetermined program, applies an ignition signal to the drive circuit 11 of each cylinder consisting of a power transistor, and switches the drive circuit 11 from on to off, thereby causing the ignition signal to flow through the ignition coil 12. The ignition voltage is sequentially applied to the ignition plugs 13 of predetermined cylinders. Next, in Figure 2, tl! ! Control unit 10 showing function configuration
The operation will be explained based on the flowcharts shown in FIGS. 5 and 6. First, in step S1 in FIG. 6, the cooling water temperature signal T w from the water temperature sensor 8, the cam pulse from the cam angle sensor 6, and the crank pulse from the crank angle sensor 3 are taken in, and the cam pulse is converted into a waveform by the pulse shaping means 20. Further, the cooling water temperature signal Tw is inputted to the water temperature determination means 21, and the crank pulse is waveform-shaped by the pulse shaping means 22 and inputted to the engine rotation speed calculation means 23, where the engine rotation RNE is calculated. Then, the process proceeds to step S2, where the waveform-shaped cam pulse is input to the frequency dividing means 24 and frequency-divided, and the air amount determining means 25 performs air amount determination. That is, the cam pulse group (5a to 5d)
The number of cam pulses in the cam pulse group is counted, and the cylinder to be ignited next is, for example, #1 cylinder when the number of cam pulses in the cam pulse group is 2 (5a), that is, when the number of cam pulses is n, it is #(n-
1) It is determined that the cylinder is a cylinder, and this determination signal is sent to the ignition selection means 26.
is input. Then, in step S3, the engine rotation speed signal from the engine rotation speed calculation means 23 is input to the ignition selection means 26, and it is determined whether the engine rotation speed NE is equal to or lower than a predetermined rotation speed N1 (for example, 300 to 400 rpm). If NE≦N1, it is determined that the engine has started, and the process proceeds to step S4; if NE>Nf, it is determined that the engine starting has not been completed, and the process proceeds to step s7.
Then, ignition control is performed using time ffi control, which will be described later. "When starting" When it is determined in step S3 that it is starting, the process proceeds to step S4, where the water temperature determining means 21 determines whether the cooling water temperature TW is equal to or lower than a predetermined temperature Tvtr1 (for example, 30"C). When ≦T w 1, engine cold start mode b
When it is determined that
The first cam pulse (5a2, 5b2, 5c2, 5d2) is frequency-divided and input to the ignition pulse generation means 27, and the ignition pulse signal synchronized with the second cam pulse is input to the ignition selection hand by the ignition pulse generation means 27. As shown in FIGS. 3 and 4, the top dead center (TD
In C), four cam pulse groups for the next #33 cylinder (
5b) is input, it is determined that the next cylinder to be ignited is the #3 cylinder as in step S2 above during the cylinder discrimination period, and when the next cam pulse group (5C) is input, this cam pulse group (5C) is input. In synchronization with the second cam pulse <5C2), the ignition pulse signal is sent from the ignition pulse generation means 27 to the drive circuit 11 of the #3 cylinder via the ignition selection means 26, and the transistor is momentarily switched from on to off. spark plug 1
Ignition at TDC by the discharge of 3. Fl! ! Similar control is performed for the cylinders, and when the engine is started in a cold state, the ignition is controlled in starting mode b as shown in the time chart in Fig.
Since ignition is performed at DC), smooth starting is possible. On the other hand, in step S4, restart mode a after engine warm-up is selected.
If it is determined that
1, the frequency dividing means 24 divides the cam pulses of the first note in the cam pulse group (5a1°5b1, 5c
1,5dl> is frequency-divided, and a synchronized Lr,-ignition pulse signal is similarly outputted from the ignition pulse generating means 27, and the corresponding cylinder is set to a constant ignition timing on the advance side (for example, T
Ignite at 5° before DC). That is, when starting the engine when the engine is set to @, the starting mode a in the time chart of Fig. 4 is selected.
is selected and the engine is ignited at a certain timing on the advance side, resulting in a smooth start. ``During normal control J - If it is determined in step S3 that the start is complete with NE>N1, the process advances to step S7, where crank pulse identification is performed.This crank pulse identification is based on the fifth
The process is carried out as shown in the flowchart (steps 3100 to 8103) in the figure, and it is determined whether a cam pulse has been input between the previous and current crank pulses of the crank angle sensor 3, and if S has been input, this cam pulse The 'crank pulse following the signal is identified as A, and the next crank pulse that has not been input is identified as B. Next, the process proceeds to step S8, in which the suction pipe negative pressure calculation means 28 calculates the suction pipe negative pressure PA based on the signal from the suction pipe pressure sensor 7, and in step S9, the ignition is performed using the suction pipe negative pressure PA and the engine speed NE as parameters. The timing calculating means 29 reads out the basic ignition timing ANGSP from a map stored in advance in the ROM, and then calculates the basic ignition timing ANGSP in step S1.
0, counts the time T1 between crank pulses A and B, and advances to step S11 to set the ignition timing TSP to TSPK = (TI / θ)XANGSP using the previously known angle θ between crank pulses A and B. In step 312, the timer means 30 sets this ignition timing (time from crank pulse B to ignition time) TSP.
Set to . Then, in step S13, the timer means 30 starts timing when the identified crank pulse B is input, and when the set ignition timing T SPH is reached,
In step 814, the ignition pulse signal is input to the ignition selection means 26. At this time, the ignition selection means 26 ignores the ignition pulse signal from the ignition pulse generation means 2γ and selects the ignition signal synchronized with the ignition pulse signal from the timer means 30 for the drive circuit 11 of the cylinder corresponding to the cylinder discrimination signal. Outputs a signal and ignites the corresponding cylinders in sequence. In this way, under normal conditions, it is controlled according to the engine operating condition using the time control method! &Perform appropriate ignition control. [Second Embodiment] Next, a second embodiment will be described with reference to the flowchart of FIG. 7. In this embodiment, the selection of the starting mode in the first embodiment is performed using engine speed N instead of cooling water temperature TW.
This is done by E. Similarly to the first embodiment (FIG. 6), in step S3, the engine rotation speed NE is set to a predetermined rotation speed N1 (for example, 30
0 to 400 rpm), it is determined that the engine has started, and the process proceeds to step 84°, where the ignition selection means 26 determines whether or not the engine rotation speed NE is below the set rotation speed N2 (for example, 10,100 rpm. That is, Since the viscosity of engine oil, gear oil, etc. is high and the friction is large, the engine starting rotation speed by the starter is low, and if NE≦N2, it is determined that the engine is started cold, and the process proceeds to step S6, where the first implementation is performed. As explained in the example, ignition in starting mode b is performed as shown in the time chart of FIG. 4. Meanwhile, in step 34', NE>N
When it is determined as 2, that is, when the engine is started while the engine is warmed up, the friction is small and the engine starting rotation speed is high, so it is determined that the engine is started when the engine is warmed up, and the starting mode is set in step S5. a is selected. In addition, in this second embodiment, the water temperature sensor 8 and the water temperature determination means 21 in the first embodiment are unnecessary, so
The structure of the ignition timing control device becomes simpler. [Third Embodiment] A third embodiment will be described with reference to the functional block diagram of FIG. 8 and the flowchart of FIG. 9. In this embodiment, the starting mode in the first embodiment is selected based on the engine speed NE and the cooling water temperature Tw, so steps 81 to 33 and step 87
-S14 performs the same operation as in the first embodiment (FIG. 6), so the details will be omitted. In step S3, when the engine rotation speed NE calculated by the engine rotation speed calculation means 23 is less than or equal to the predetermined rotation speed N1 (for example, 300 to 400 rpm>), it is determined that the engine is starting, and the process proceeds to step 315, where the engine speed search means 31, the engine speed N at that time is determined from a map 32 stored in advance in the ROM as shown in FIG. 10 using the engine speed NE and cooling water temperature Tw as parameters.
The starting mode is searched based on E and the cooling water temperature Tw. That is, starting mode b is selected only when the cooling water 4Tw is lower than the set temperature Tw□ (for example, 30°C) and the engine speed NE is lower than the set speed No (for example, 10100 rpm), and at other times Starting mode a
is selected (step 316). Then, a starting mode signal is output from the starting mode searching means 31 to the frequency dividing means 24, and when the starting mode b at the time of cold starting of the engine is input as in the first embodiment, the second output of the cam pulse group is output. Note cam pulse (5a2, 5b2,
5c2, 5d2) is frequency-divided and sent to the ignition pulse generating means 27, and the corresponding cylinders are sequentially ignited at the retarded TDC in synchronization with the two cam pulses. On the other hand, when starting mode a is input when restarting the engine after warming up, the first cam pulse of the cam pulse group (5a1
．． 5b1, 5c1. 5d1) is frequency-divided by the frequency dividing means 24 and sent to the ignition pulse generating means 27, and the corresponding cylinders are sequentially ignited at 5@ before TDC on the advance side synchronized with the first cam pulse. In this third embodiment, starting modes a and b are determined from a combination of engine speed and engine cooling water temperature, so more appropriate ignition control at starting can be performed, regardless of the engine state. It becomes possible to perform a smooth start. In each of the above embodiments, one of the two starting modes a and b is selected based on the engine rotation speed at one set rotation speed and the engine cooling water temperature at one set temperature. However, the number of cam pulses in the cam pulse group is at least 3, and the engine speed is 2.
One of three or more starting modes may be selected based on two or more set engine speeds or two or more set engine coolant temperatures; in this case, Ignition control at the time of starting can be performed more appropriately. In each of the above embodiments, the basic ignition timing is determined from the engine speed and the suction pipe's negative pressure, but instead of the suction pipe's negative pressure, the throttle opening or fuel injection to an injector (not shown) is determined. Pulse width may also be used.

【Effect of the invention】

As described above, according to the present invention, ignition timing control is performed using a time control method during normal operation, and when starting the engine, the starting mode is determined based on the engine cooling water temperature and/or the engine speed, and the cold starting mode is set. When the cylinder discrimination pulse of the second note of the cylinder discrimination pulse group (for example, T
The ignition is controlled on the retarded side in synchronization with DC), and in the restart mode after warm-up (or in the extremely low rotation range such as when idling), the cylinder discrimination pulse of the first note of the cylinder discrimination pulse group is used. (for example, 5 degrees before TDC), the ignition is controlled on the advance side in synchronization with the ignition angle (for example, 5 degrees before TDC), so the appropriate ignition timing can be achieved regardless of the engine operating condition without increasing the cost of hardware or software. can be set, and startability can be significantly improved without interfering with drivability during normal operation.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention, FIG. 1 is an overall configuration diagram of an ignition timing control device, and FIG.
The figure is a block diagram showing the tS function configuration of the control unit.
The figure shows the detection position of crank angle and cam angle,
Fig. 4 is a time chart of crank pulses and cam pulses, Fig. 5 is a flow chart of crank pulse identification operation, Fig. 6 is a flow chart of ignition time calculation operation, and Fig. 7 is a second embodiment of the present invention. Flowcharts of a certain ignition time calculation operation, FIGS. 8 to 10 show a third embodiment of the present invention, FIG. 8 is a functional block diagram of the control unit, and FIG. 9 is a flow chart of an ignition time calculation operation. FIG. 10 is a flowchart diagram showing a map of the starting mode. 3... Crank angle sensor, 6... Cylinder discrimination sensor (
cam angle sensor), 7... suction pipe pressure sensor, 8...
Cooling water temperature sensor, 10... control unit, 21...
Water temperature determination means, 23...Engine rotation speed calculation means, 2
4... Frequency dividing means, 26... Ignition selection means, 27...
- Ignition pulse generation means, 29...Ignition timing calculation means,
30...Timer means, 31...Starting mode search means, 32...Starting mode map. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Nobuko Konobu Uketsu Patent Attorney Susumu Murai Ghod G Koetsu

Claims (3)

[Claims] (1) A cylinder discrimination sensor that detects a plurality of cam angles for each cylinder and outputs a group of cylinder discrimination pulses each consisting of at least two pulses, and a crank pulse A that detects at least two predetermined crank angles. , B, and a control unit that inputs pulse signals from the above-mentioned sensors to time-control the ignition timing, and the control unit calculates the engine speed based on the crank pulses A and B. Engine rotation speed calculation means,
ignition timing calculation means for calculating ignition timing based on engine speed and engine load; timer means for converting the calculated ignition timing into ignition time; and water temperature determination means for determining the state of the engine at the time of starting based on engine cooling water temperature. ,
frequency dividing means for frequency dividing the first or second cylinder discrimination pulse of the group of cylinder discrimination pulses according to the determined engine condition; and ignition in synchronization with the divided cylinder discrimination pulse. An ignition pulse generating means for generating a pulse (ignition time), and ignition time determined by the ignition pulse generating means or ignition by the timer means by determining whether the engine is starting or during normal operation after starting from the calculated engine rotation speed. ignition selection means for selecting one of the times, and when the engine state is determined to be restarting after completion of warm-up, the frequency dividing means selects an advance angle from among the cylinder discrimination pulse group. The first cylinder discrimination pulse, which is the side,
When it is determined that it is a cold start, the frequency of the second cylinder discrimination pulse, which is on the retarded side, is divided, and an ignition pulse synchronized with this is outputted from the ignition pulse generation means. An ignition timing control device characterized by: (2) The engine state is determined based on the calculated engine speed, and when the engine speed is below a predetermined speed, it is determined to be a cold start, and the frequency dividing means generates the second cylinder discrimination pulse group. The cylinder discrimination pulse of
2. The ignition timing control device according to claim 1, wherein the frequency of the first cylinder discrimination pulse is divided, and the ignition pulse is output from the ignition pulse generation means in synchronization with the frequency division. (3) The above-mentioned engine state is determined by searching a starting mode map using the engine speed and engine cooling water temperature as parameters, and when it is determined that the cold starting mode is selected, the above-mentioned frequency dividing means causes the first When it is determined that the second cylinder discrimination pulse is in restart mode after completion of warm-up, the frequency of the first cylinder discrimination pulse is divided, respectively.
2. The ignition timing control device according to claim 1, wherein the ignition pulse generation means outputs an ignition pulse in synchronization with this.