JP2631862B2 - Ignition timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

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 and sets an ignition timing.

[Prior art]

Conventionally, as this type of time control type ignition timing control device, there has been one disclosed in, for example, JP-A-61-120918. The above-mentioned ignition timing control device forms a large number of teeth for generating a crank angle signal on the outer circumference, and embeds a magnetized body in a predetermined one of the teeth to form a tooth for generating a reference position signal. And a pickup provided at a position facing the teeth of the rotating body constitute a crank angle detector,
By reducing the number of parts and reducing costs, the time of the specific number of teeth section is divided and the crank angle (unit angle) signal is converted and generated, thereby improving the crank angle resolution.
This is to improve the accuracy of the time control type ignition timing control. However, in this method, since the engine speed is low when the engine is started, the ignition timing from the reference pulse signal position becomes long, and the fluctuation of the engine speed is large even within one cycle, so that the ignition timing varies. I could not start smoothly. Accordingly, the applicant of the present application has previously proposed the one shown in Japanese Patent Application No. 62-215978. In this time control type ignition timing control device, the cam pulse signal from the cam angle sensor is configured to enter at, for example, 10 ° before the top dead center (TDC) of the crank angle, and the crank angular velocity is set between crank pulses for which no cam pulse is detected. Calculate a cycle which is information, convert this into a time from a crank pulse (reference signal) at the end of the cycle, determine an ignition time and ignite, and when starting the engine when the engine speed becomes unstable, An ignition signal is output based on a cam pulse with small angle fluctuations to reduce ignition timing fluctuations at engine start,
The engine can be started smoothly.

[Problems to be solved by the invention]

By the way, in the technology described in Japanese Patent Application No. 62-215978 described above, since ignition is performed in response to a cam pulse, variations in ignition timing are eliminated and startability in that sense is improved. However, since the ignition timing at the start of the engine is uniquely set, the startability may not be good depending on the operating state of the engine. For example, when the cam pulse position is set to the retard side, the startability deteriorates when the engine is restarted in a warm-up state. Further, when the cam pulse is advanced, the startability of the engine is deteriorated when the engine is cold, particularly in winter or cold regions. As described above, there has been a problem that the cam pulse position has to be set at an intermediate position that is not optimal in any of the above cases. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide an ignition timing control device that can start an engine satisfactorily in any engine state.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a cylinder discriminating sensor that detects a plurality of cam angles for each cylinder and outputs a cylinder discriminating pulse group in which one group includes at least two pulses, and at least two predetermined crankshafts. A crank angle sensor that detects an angle and outputs crank pulses A and B, and a control unit that inputs a pulse signal from each of the above sensors and controls the ignition timing over time, includes:
Engine speed calculating means for calculating the engine speed based on the crank pulses A and B; ignition timing calculating means for calculating the ignition timing based on the engine 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 first or second cylinder determination pulse of the cylinder determination pulse group according to the determined engine state. Frequency dividing means for dividing the frequency, ignition pulse generating means for generating an ignition pulse (ignition time) in synchronization with the divided cylinder discriminating pulse, and a normal time after or after the start of the engine based on the calculated engine speed. Ignition selection means for judging whether it is in operation and selecting either the ignition time by the ignition pulse creation means or the ignition time by the timer means. When it is determined that the determination of the engine state is a restart time after completion of warming-up, the first cylinder determination pulse on the advance side of the cylinder determination pulse group is determined by the frequency dividing means. When it is determined that the engine is in a cold start, the second cylinder discriminating pulse on the retard side is frequency-divided, and an ignition pulse synchronized with the frequency is output from the ignition pulse generating means. Things.

[Action]

Based on the above configuration, during normal operation, based on the ignition timing calculated by the ignition timing calculation means according to the operating state,
The ignition timing control based on the time control method is executed. On the other hand, when the engine start time is determined based on the engine speed, the ignition selecting means selects the ignition time from the ignition pulse generating means, and at the time of the cold engine start, the ignition timing is determined on the retard side which is the second generation of the cylinder determination pulse group. At the time of restart after completion of warm-up of the engine, ignition is performed on the advance side, which is the first shot, and good engine start can be performed in any engine state.

【Example】

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 6, a second embodiment with reference to FIG. 7, and a third embodiment with reference to FIGS. 8 to 10. First Embodiment In FIG. 1, a crank rotor 2 for detecting a crank angle position is attached to a crankshaft 1 of an engine, and a predetermined angular position of a crank angle is provided on a peripheral edge of the crank rotor 2. 4 to generate a pulse at
The protrusions 2a, 2b, 2c, 2d are arranged, for example, the protrusions 2a, 2c 112 mm before TDC, and the protrusions 2b, 2d are arranged 80 ° before TDC. 2a, 2c) and a crank angle sensor 3 that generates a crank pulse B (projections 2b, 2d) are arranged to face each other. On the other hand, a cam rotor 5 for detecting a cam angle position is attached to a camshaft 4 that makes one rotation with two rotations of the crankshaft 1.
Projection group 5a of other generating the cylinder discrimination pulse group at a predetermined angular position of the cam angle, 5b, 5c, 5d is the number obtained by adding 1 to the cylinder number in response to the firing order (5a ₁ to 5 A _2, 5b ₁ ~ 5b ₄ , 5c ₁ 〜5c ₃ , 5d ₁
~5d ₅₎ in disposed 90 ° intervals, and the crank angle pulse two kinds of crank pulses A, as well as classified into B, the first shot eyes as a reference signal during start after completion of the warm-up of the engine In order to generate a cam pulse as a cylinder discrimination pulse, four projections 5a ₁ , 5b ₁ , 5c ₁ , and 5d ₁ are generated, for example, 5 ° before TDC, and a second cam pulse serving as a reference signal is generated during a cold start. For example, the four projections 5a ₂ , 5b ₂ , 5c ₂ , 5d ₂ are set to, for example, TDC, and the following projections are set at intervals of 5 °. A cam angle sensor 6 serving as a cylinder discrimination sensor is opposed to the cam rotor 5. It is arranged. FIG. 3 shows the arrangement of the projections on the crank rotor 2 and the cam rotor 5, and pulse signals from the crank angle sensor 3 and the cam angle sensor 6 serving as a cylinder discriminating sensor are output at timings shown in FIG. Generated and input together with a suction pipe pressure sensor 7 for detecting a pressure in the suction pipe as an example of an engine load and a cooling water temperature sensor 8 for detecting an engine cooling water temperature to a control unit 10 including a microcomputer for performing ignition timing control. . Then, the control unit 10 calculates an ignition timing according to a predetermined program, gives an ignition signal to the drive circuit 11 of each cylinder composed of a power transistor, and switches the drive circuit 11 from on to off, thereby via the ignition coil 12. The ignition voltage is sequentially applied to the ignition plugs 13 of the predetermined cylinders. Next, the operation of the control unit 10 whose functional configuration is shown in FIG. 2 will be described based on the flowcharts shown in FIGS. First, in step S1 of FIG. 6, the cooling water temperature signal Tw 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 fetched. Further, the cooling water temperature signal Tw is input to the water temperature determining means 21, and the crank pulse is shaped by the pulse shaping means 22 and input to the engine speed calculating means 23, where the engine speed NE is calculated. You. Then proceed to step S2,
The cam pulse whose waveform has been shaped is input to the frequency dividing means 24 and divided, and the cylinder discriminating means 25 performs cylinder discrimination. That is, the number of cam pulses of the cam pulse group (5a to 5d) is counted. When the next cylinder to be ignited is, for example, the number of cam pulses of the cam pulse group is 2 (5a), the cylinder is # 1 cylinder, that is, when the number of cam pulses is n, The cylinder is determined to be a # (n-1) cylinder, and this determination signal is input to the ignition selecting means 26. Then, in step S3, is input to the engine speed signal is an ignition selection means 26 from the engine speed calculating means 23, whether the engine speed NE is the predetermined rotational speed N ₁ (e.g., 300-400 rpm) or less is determined, if NE ≦ N ₁ proceeds is determined that the engine start by the step S4, NE> of the time N ₁ is determined as the start of the engine is completed and proceeds to step S7, the ignition by the time control described later Perform control. "Starting" If it is determined in step S3 that the engine is starting, step
Proceeding to S4, the cooling water temperature Tw is set to the predetermined temperature Tw by the water temperature determining means 21.
It is determined whether or not ₁ (e.g. 30 ° C.) or less, when the Tw ≦ Tw ₁ is being determined that the engine cold start mode b proceeds to step S6, a signal from a water temperature determining means 21, the frequency dividing means 24 The second cam pulse (5a ₂ , 5b ₂ , 5c ₂ , 5d
₂ ) is divided and input to the ignition pulse generation means 27, and an ignition pulse signal synchronized with the second cam pulse is input from the ignition pulse generation means 27 to the ignition selection means 26, and the ignition pulse signal is generated by the cylinder discrimination signal. As shown in FIGS. 3 and 4, for example, at the top dead center (TDC) of the # 1 cylinder, when four cam pulse groups (5b) for the next # 3 cylinder determination are input, during the cylinder determination period, When the next cylinder to be ignited is determined to be the # 3 cylinder as in step S2 and the next cam pulse group (5c) is input, the second cam pulse (5c)
_In synchronization with ₂ ), an ignition pulse signal is sent from the ignition pulse generating means 27 to the drive circuit 11 of the # 3 cylinder via the ignition selecting means 26, and the transistor is switched from on to off for a moment, and the spark plug 13 discharges. Ignite at TDC. Similar control is performed for the other cylinders, and when the engine is cold started, the ignition is controlled in the start mode b as shown in the time chart of FIG.
Since ignition is performed in C), a smooth start is possible. On the other hand, in step S4, the restart mode a after the engine is warmed up
If it is determined that, the process proceeds to step S5, the signal from the water temperature determination section 21, a first shot first cam pulse in cam pulse group by frequency dividing means _{24 (5a 1, 5b 1,} 5c 1, 5d 1) is divided The ignition pulse signal synchronized with this is output from the ignition pulse generating means 27 in the same manner, and the corresponding cylinder is ignited at a constant ignition timing on the advance side (for example, 5 ° before TDC). That is, when the engine is started when the engine is warmed up, the start mode a in the time chart of FIG. 4 is selected, and ignition is performed at a fixed timing on the advance side, so that a smooth start is performed. If it is determined that the start completion with NE> N ₁ in the "normal control when" the step S3, the process proceeds to step S7, the crank pulse identification is performed. This crank pulse identification is performed as shown in the flowchart of FIG. 5 (steps S100 to S103).
It is determined whether or not a cam pulse has been input between the previous and current crank pulses of the crank angle sensor 3, and if it has been input, the crank pulse following this cam pulse signal is set to A, and the next crank pulse that has not been input is set to A. Identify as B. Next, the routine proceeds to step S8, where the suction pipe negative pressure calculating means 28 calculates the suction pipe negative pressure PA based on the signal of 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 unit 29 reads out the basic ignition timing ANGSPK from the map stored in advance in ROM, the program proceeds to step S10, the crank pulse a, counts time T ₁ of the inter-B, the ignition timing control proceeds to step S11 TSPK TSPK = (T ₁ / θ) × ANGSPK with the known angle θ between the crank pulses A and B, and this ignition timing (the time from the crank pulse B to the ignition time) TSPK is determined by a timer in step S12. Means 3
Set to 0. Then, in step S13, the timer means 30
Starts timing when the identified crank pulse B is input, and when the set ignition timing TSPK is reached, the step S
At 14, an ignition pulse signal is input to the ignition selecting means 26. At this time, the ignition selection means 26
The ignition signal synchronized with the ignition pulse signal from the timer means 30 is output to the drive circuit 11 for the cylinder corresponding to the cylinder discrimination signal, and the corresponding cylinder is sequentially ignited, ignoring the ignition pulse signal from the cylinder. In this way, at normal times, optimal ignition control is performed in accordance with the operating state of the engine by the time control method. Second Embodiment Next, a second embodiment will be described with reference to the flowchart of FIG. In this embodiment, the selection of the start mode in the first embodiment is performed by replacing the cooling water temperature Tw with the engine speed N.
This is done by E. Similar to the first embodiment (FIG. 6), in step S3, the engine speed NE is the predetermined rotational speed N ₁ (e.g., from 300 to 40
0 rpm) or less, it is determined that the engine is
Proceeds to S4 ', it is determined whether or not the engine rotational speed NE is equal to or less than the set rotational speed N ₂ (e.g., 100 rpm) in the ignition selection means 26. That is, high viscosity, such as engine oil or gear oil is, since friction is large, low engine starting rotational speed by the starter, in the case of NE ≦ N _2, it is determined that the engine cold start, the program proceeds to step S6, first In the same manner as described in the embodiment, ignition in the start mode b is performed as shown in the time chart of FIG. Meanwhile, when it is determined that NE> N ₂ at step S4 ', i.e. when the engine starts in a state in which the engine is warmed up, since the friction is small engine starting rotational speed increases, starting at the time of engine warmup Is determined, and the start mode a is selected in step S5. In the second embodiment, since the water temperature sensor 8 and the water temperature determination means 21 in the first embodiment are not required,
The structure of the ignition timing control device is simplified. Third Embodiment A third embodiment will be described with reference to a functional block diagram of FIG. 8 and a flowchart of FIG. In this embodiment, the start mode in the first embodiment is selected based on the engine speed NE and the cooling water temperature Tw. Steps S1 to S3 and steps S7 to S14 are performed in the first embodiment ( Since the same operation as in FIG. 6) is performed, the details are omitted. In step S3, the engine rotational speed NE calculated by the engine speed calculating means 23 a predetermined rotational speed N ₁ (e.g., 300
If the engine speed is equal to or less than 400 rpm, it is determined that the engine is being started, and the process proceeds to step S15. The starting mode search means 31 stores the engine speed NE and the cooling water temperature Tw as parameters in the ROM.
As shown in FIG. 10, a start mode is searched from a map 32 stored in advance based on the engine speed NE and the coolant temperature Tw at that time. That is, the cooling water temperature Tw becomes the set temperature Tw _o
(E.g., 30 ° C.) lower than, and the engine rotational speed NE is selected set rotational speed N _o (e.g. 100 rpm) starting mode b only when less than, the starting mode a is selected in other cases (step S16 ). Then, a start mode signal is output from the start mode search means 31 to the frequency dividing means 24, and when the start mode b at the time of cold engine start is input as in the first embodiment, the second pulse of the cam pulse group is generated. The second cam pulse (5a ₂ , 5b ₂ , 5c ₂ , 5d ₂ ) is frequency-divided and sent to the ignition pulse generating means 27, and the corresponding cylinder is sequentially shifted in the TDC on the retard side synchronized with the second cam pulse. Ignite. On the other hand, when the startup mode a restart time after the engine warm-up is input, a first shot first cam pulse cam pulse groups _{(5a 1, 5b 1, 5c} 1, 5d 1) is divided by the division means 24 The cylinders are sent to the ignition pulse creating means 27, and the corresponding cylinders are sequentially ignited 5 ° before TDC on the advance side synchronized with the first cam pulse. In the third embodiment, the start modes a and b are determined from the combination of the engine speed and the engine coolant temperature, so that more appropriate ignition control at the time of start can be performed, and even in any engine state. A smooth start can be performed. In each of the above embodiments, one of the two start modes a and b is selected with the engine speed set at one set speed and the engine coolant temperature set at one set temperature. However, the number of cam pulses of the cam pulse group is set to at least three or more, and the engine speed is set to two.
One of three or more start modes may be selected at one or more set rotation speeds or at two or more set temperatures for the engine cooling water temperature. In this case, More appropriate ignition control at the time of starting can be performed. In each of the above embodiments, the basic ignition timing is determined from the engine speed and the suction pipe negative pressure. However, instead of the suction pipe negative pressure, the throttle opening or the fuel injection pulse to the injector (not shown) is used. The width may be used.

【The invention's effect】

As described above, according to the present invention, during normal operation, ignition timing control is performed by the time control method, and when the engine is started, the start mode is determined based on the engine coolant temperature and / or the engine speed. Is the second cylinder discrimination pulse of the cylinder discrimination pulse group (for example,
The ignition is controlled on the retard side in synchronization with TDC), and the first cylinder discrimination pulse of the cylinder discrimination pulse group in the restart mode after warm-up is completed (or in an extremely low rotation range such as idling). (E.g., 5 ° before TDC) The ignition is controlled on the advance side in synchronization with the ignition, so that appropriate ignition can be performed regardless of the operating state of the engine without significantly increasing the cost of hardware and software. Timing can be set, and startability can be greatly improved without hindering drivability during normal operation.

[Brief description of the drawings]

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.
FIG. 3 is a block diagram showing a functional configuration of the control unit, FIG. 3 is a diagram showing detection positions of the crank angle and the cam angle, FIG. 4 is a time chart of the crank pulse and the cam pulse, and FIG. FIG. 6 is a flowchart of the ignition time calculation operation,
FIG. 7 is a flowchart of an ignition time calculation operation according to a second embodiment of the present invention, FIGS. 8 to 10 show a third embodiment of the present invention, and FIG. 8 is a control unit. FIG. 9 is a flowchart of an ignition time calculation operation, and FIG. 10 is a diagram showing a map of a start 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 speed calculation means, 24 …… Division means, 26 ……
Ignition selection means, 27 ... Ignition pulse creation means, 29 ... Ignition timing calculation means, 30 ... Timer means, 31 ... Start mode search means, 32 ... Start mode map.

Claims (3)

(57) [Claims] A cylinder discriminating sensor for detecting a plurality of cam angles for each cylinder and outputting a group of cylinder discriminating pulses, each group comprising at least two pulses;
A crank angle sensor that detects two crank angles and outputs crank pulses A and B, and a control unit that inputs a pulse signal from each of the above sensors and controls the ignition timing with time. The control unit includes the crank pulse A and B, an engine speed calculating means for calculating the engine speed, an ignition timing calculating means for calculating the ignition timing based on the engine speed and the engine load, a timer means for converting the calculated ignition timing to ignition time, Water temperature determining means for determining the state of the engine at the time of starting based on the engine cooling water temperature, and dividing the first or second cylinder discriminating pulse of the cylinder discriminating pulse group according to the determined engine state. Frequency dividing means; and ignition pulse generating means for generating an ignition pulse (ignition time) in synchronization with the divided cylinder discrimination pulse. Ignition selection means for judging whether the engine is started or normal operation after the start based on the engine speed and selecting either the ignition time by the ignition pulse creation means or the ignition time by the timer means. If it is determined that the state is determined to be a restart after completion of warm-up, the first cylinder determination pulse on the advance side of the cylinder determination pulse group is determined by the frequency dividing means.
When it is determined that the engine is in a cold start, the second cylinder discriminating pulse on the retard side is frequency-divided, and an ignition pulse synchronized with the frequency is output from the ignition pulse generating means. An ignition timing control device, characterized in that: 2. The engine state is determined based on the calculated engine speed. If the engine speed is lower than a predetermined speed, it is determined that the engine is in a cold start. The frequency dividing means determines the second pulse of the cylinder determination pulse group. When the number of revolutions is equal to or higher than a predetermined number of revolutions, the first cylinder discrimination pulse is frequency-divided, and an ignition pulse is output from the ignition pulse generation means in synchronization with the frequency. The ignition timing control device according to claim 1. 3. The engine state is determined by searching a start mode map using the engine speed and the engine coolant temperature as parameters. When the engine is in the cold start mode, the cylinder discriminating pulse group is determined by the frequency dividing means. When the second cylinder discrimination pulse is determined to be in the restart mode after completion of warm-up, the first cylinder discrimination pulse is frequency-divided. 2. The ignition timing control device according to claim 1, wherein the ignition timing control device outputs the ignition timing.