JP3985597B2 - Ignition device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine ignition device that controls the ignition timing of an internal combustion engine using a microcomputer.
[0002]
[Prior art]
An ignition device for an internal combustion engine includes an ignition circuit that generates a high voltage to be applied to an ignition plug attached to a cylinder of the internal combustion engine when an ignition signal is given, and rotation information (rotational speed information and A signal generator for generating a signal having a crank angle information), and the engine ignition timing is determined using a microcomputer with respect to the engine rotational speed information obtained from the signal generator, and the determined ignition timing is detected. And an ignition timing control unit that provides an ignition signal to the ignition circuit when the ignition circuit is set.
[0003]
As a signal generator, a rotor with a reluctator normally attached to a crankshaft of an internal combustion engine, and a pulse having a first polarity when a front end side edge and a rear end side edge in the rotation direction of the reluctator of the rotor are detected, respectively. A signal generator and a pulser (signal emission) that generates a pulse signal of the second polarity are used. Here, the first polarity and the second polarity are different from each other. For example, when the first polarity is negative, the second polarity is positive.
[0004]
FIG. 7A shows an example of waveforms of the first polarity pulse signal P1 and the second polarity pulse signal P2 output from a signal generator used conventionally. In the figure, 360 ° represents one revolution of the crankshaft, and Tp represents the time required for one revolution of the crankshaft. Α represents the polar arc angle of the reluctator provided in the rotor of the signal generator, and ΔT represents the first polarity pulse signal P1 after the pulser detects the front end edge in the rotation direction of the reluctator and The time (reactor passing time) from when the rear end side edge in the rotation direction is detected to when the second polarity pulse signal P2 is generated is shown. This signal generator has a first polarity at a reference timing t1 corresponding to a reference crank angle position θ1 set to a position sufficiently advanced with respect to the crank angle position when the piston of the engine reaches top dead center TDC. A pulse signal P1 is generated, and a pulse signal P2 having the second polarity is generated at a timing t2 corresponding to the crank position θ2 that is delayed from the reference crank position and slightly advanced from the crank angle position corresponding to the top dead center. The timing t2 at which the second polarity pulse signal P2 is generated is set to a timing corresponding to a crank angle position suitable as an ignition timing at the start of the engine.
[0005]
Assuming that the polar arc angle of the relaxer is α and the multiplication symbol is *, there is a difference between the above-mentioned reluctator passing time ΔT (the time required for the crankshaft to rotate the angle α) and the engine speed N [rpm]. There is a relationship of the following formula (1).
[0006]
ΔT = (α / 360) * (6 * 10 ⁷ / N) (1)
In FIG. 7A, the timing at which each pulse signal is generated is the timing at which each pulse signal reaches the threshold level Vth recognized by the microcomputer.
[0007]
Usually, the ignition timing control unit ignites the ignition circuit when a predetermined timing is detected as the ignition timing at the start of the internal combustion engine until the rotation speed is stabilized after the start of the internal combustion engine. Ignition point supply means for giving a signal at the start time and ignition timing after engine startup is calculated by the microcomputer with respect to the rotational speed information obtained from the output of the signal generator, and ignition is performed when the calculated ignition timing is detected It is comprised with the steady operation time fire signal supply means which gives an ignition signal to a circuit.
[0008]
When a signal generator for generating pulse signals P1 and P2 as shown in FIG. 7 is used as a signal generator for detecting rotation information of the internal combustion engine, a pulse signal generation interval (for example, an interval between P1 and P2). By detecting this, the rotational speed information of the engine can be obtained.
[0009]
In addition, when the engine has been started and its rotation is stable, the timing at which the pulsar is generated at a specific crank angle position is used as a reference timing, and the ignition timer starts measuring the ignition timing at this reference timing. By doing so, it is possible to detect the ignition timing at the time of the calculated steady operation (in a state where the start of the engine is completed and the rotation speed is stable).
[0010]
For example, the timing t1 when the pulser detects the front end edge of the reluctator and generates the first polarity pulse signal P1 is set as the reference timing, and the elapsed time from the reference timing to the ignition timing ti (the crank corresponding to the reference timing) (Time required for the engine to rotate from the angular position to the crank angle position corresponding to the ignition timing) Ti is calculated as a measurement value for detecting the ignition timing, and when the first polarity pulse signal P1 is generated at the reference timing t1, The calculated ignition timing detection value Ti is set in the ignition timer and the measurement is performed, whereby the calculated ignition timing ti can be detected, and when the calculated ignition timing is detected, the ignition circuit An ignition operation can be performed by giving an ignition signal to the.
[0011]
However, when the internal combustion engine is started, the rotational speed of the crankshaft varies finely with changes in the stroke of the engine, so that it is difficult to accurately detect the ignition timing using the ignition timer as described above. Therefore, in general, the signal generator is configured to generate the pulse signal P2 having the second polarity at a timing t2 suitable as an ignition timing at the start of the engine, and the signal generator detects the rear end side edge of the reluctator. A start point fire signal supply means is provided specially for supplying an ignition signal to the ignition circuit when the second polarity pulse signal P2 is detected and generated.
[0012]
As a method for giving an ignition signal to the ignition circuit when the signal generator detects the trailing edge of the reluctator and generates the second polarity pulse signal P2, the signal generator generates the second polarity pulse signal. Sometimes, the pulse signal of the second polarity is supplied to the ignition circuit through the hardware circuit without passing through the microcomputer, and the pulse signal of the first polarity is detected by the pulser detecting the front end side edge in the rotation direction of the reluctator. The time from when P1 is generated until the trailing edge of the reluctator is detected and the second polarity pulse signal P2 is generated is measured as a reluctator passing time ΔT by a timer in the microcomputer, and the reluctator passing time is measured. There is known a method of giving an ignition signal from a microcomputer to an ignition circuit when measurement of ΔT is completed.
[0013]
When using a starter that uses human power as an operating force, such as a rope starter or kick starter, as the starting device for an internal combustion engine, the rotational speed of the crankshaft when cranking is performed at the time of start is influenced by the operating force of the driver If the operating force is insufficient, the rotational speed during cranking may be considerably low. When the crankshaft rotation speed at the start is extremely low and the signal generator generates a pulse signal of the second polarity and gives an ignition signal to the ignition circuit, the piston is dead due to the lack of the inertia force of the engine. The engine may fail to start due to being pushed back without being able to pass the point.
[0014]
Therefore, conventionally, the pass through time of the reluctator (time including information on the rotational speed of the engine) is compared with a determination reference time Ts corresponding to the lower limit Ns of the cranking speed necessary for starting the engine without any trouble. Only when the reluctator passing time ΔT is shorter than the judgment reference time Ts (when the rotational speed of the crankshaft at the start has a magnitude necessary for starting the engine), the second polarity An ignition signal is applied to the ignition circuit at the position where the pulse signal is generated. Here, the determination reference time Ts is given by the following equation.
[0015]
Ts = (α / 360) * (6 * 10 ⁷ / Ns) (2)
As an example, when the polar arc angle α of the relaxor is 30 ° and the lower limit value Ns of the cranking speed is 150 [rpm], Ts = 33333 μs.
[0016]
FIG. 6 shows an algorithm of a program executed by the microcomputer when starting the engine when such processing is performed at the time of starting the engine to perform the ignition operation. FIG. 6 shows an interrupt routine that is executed each time the signal generator generates a pulse signal of the second polarity in a state before the engine speed reaches the start completion speed when the internal combustion engine is started. . In the case of this algorithm, the reluctator passage time ΔT measured by the timer in step 1 is stored in the RAM, and in step 2, it is determined whether or not the reluctor passage time ΔT measured this time is shorter than the determination reference time Ts. As a result, when it is determined that the reluctator passing time ΔT is equal to or greater than the determination reference time Ts, it is determined that the cranking speed is too low, and the process proceeds to step 3 to prohibit the ignition circuit from being given an ignition signal and misfire the engine. After that, other necessary processing is performed in step 4 and thereafter, and the process returns to the main routine.
[0017]
In Step 2, when it is determined that the measured reluctator passage time ΔT is shorter than the determination reference time, the cranking speed is sufficiently high and the process proceeds to Step 5 to give an ignition signal to the ignition circuit to perform an ignition operation. Thereafter, the necessary processing is performed in step 4 and thereafter, and the process returns to the main routine.
[0018]
[Problems to be solved by the invention]
As shown in FIG. 7A, the output of the signal generator does not include noise, and the first polarity pulse signal generated when the pulser detects the front end side edge and the rear end side edge of the reluctator, respectively. When only the P1 and the second polarity pulse signal P2 are recognized by the microcomputer, the shortage of the cranking speed at the start-up can be determined by determining the length of the pass through the reciprocator with an algorithm as shown in FIG. By detecting, it is possible to prevent an unnecessary ignition operation that leads to a failure in starting the engine.
[0019]
However, as shown in FIG. 7B, when noise Pn is added to the signal output by the pulser due to vibration generated during cranking, the first signal having the same polarity as the pulse signal P2 having the second polarity of the noise Pn. This is the case when the cranking speed is lower than the set speed because the time measured by the timer for measuring the elapsed time of the reluctator at the timing tn1 when the peak exceeds the threshold level is taken into the microcomputer as the reluctator passing time ΔT '. However, it is erroneously determined that the reluctator passing time is shorter than the determination reference time Ts. When such a state occurs, the ignition operation is performed in a state where the cranking speed is insufficient, so that the piston may be pushed back without exceeding the top dead center, and the engine may fail to start.
[0020]
In particular, when the timing at which the timer completes the measurement of the reluctator passage time ΔT is used as the ignition timing at the start of the engine, if the elapsed time of the reluctator is measured shorter than the actual time due to the noise Pn as described above, Since ignition is performed at the advance position, the probability that the piston is pushed back and the engine fails to start increases.
[0021]
It is an object of the present invention to perform an unnecessary ignition operation because the cranking speed is erroneously determined to be appropriate due to noise mixed in the output of the signal generator even though the cranking speed is insufficient at the start of the engine. It is an object of the present invention to provide an ignition device for an internal combustion engine that can prevent a phenomenon in which a piston of an engine is pushed back.
[0022]
[Means for Solving the Problems]
The present invention relates to an ignition circuit that generates a high voltage to be applied to an ignition plug attached to a cylinder of an internal combustion engine when an ignition signal is given, and rotation of a reluctator provided in a rotor that rotates synchronously with the internal combustion engine. A signal generator that generates a first polarity pulse signal and a second polarity pulse signal when a front edge and a rear edge of the direction are detected, respectively, and the signal generator generates a first polarity pulse signal Time measuring means for measuring the time required to generate the pulse signal of the second polarity as the reluctator passing time, and from the start of the start of the internal combustion engine until the rotation speed is stabilized, A starting point fire signal supply means for detecting a predetermined ignition timing as an ignition timing at the start of the internal combustion engine and supplying an ignition signal to the ignition circuit; and a constant after the rotational speed of the internal combustion engine is stabilized. Ignition for an internal combustion engine comprising ignition timing determining means for determining an ignition timing during operation, and steady operation point fire signal supply means for detecting the ignition timing determined by the ignition timing determining means and providing an ignition signal to the ignition circuit Intended for equipment.
[0023]
In the present invention, the start point fire signal supply means is compared with the first determination reference time Ts when the reluctator passage time is measured every time the reluctator elapsed time measuring time means measures the reluctor passage time. The supply of the ignition signal to the ignition circuit is permitted when the pass time of the reluctor is shorter than the first determination reference time, and the ignition signal is sent to the ignition circuit when the pass time of the reluctator exceeds the first determination reference time. The first criterion for determining the passage time of the reluctator in a state in which the first start-time fire permission / prohibition means prohibiting the application and the supply of the ignition signal to the ignition circuit are permitted by the first start-time fire permission / rejection means. An ignition signal is supplied to the ignition circuit when the reluctator passage time exceeds the second determination reference time as compared to the second determination reference time Ts ′ set shorter than the time, and the reluctor passage time is the second. Judgment of When the time is equal to or shorter than the reference time, a second starting point fire permission / refusal means for prohibiting the supply of the ignition signal to the ignition circuit is provided.
[0024]
The first determination reference time Ts is set equal to the reluctator elapsed time corresponding to the lower limit value Ns of the appropriate range of the cranking speed at the start of the engine.
[0025]
Further, the second determination reference time Ts ′ is set equal to the pass-through time of the retractor corresponding to a value in the vicinity of the lower limit value of the high cranking speed that cannot normally be obtained at the start.
[0026]
Generally, when it is assumed that a cranking speed equal to or higher than a speed k * Ns that is k times the lower limit value Ns (k is an integer or decimal number exceeding 1) of the appropriate range of the cranking speed when the engine is started is The determination reference time Ts ′ is set to Ts / k, for example.
[0027]
That is, in the present invention, when it is determined that the reciprocator passage time is shorter than the first determination reference value corresponding to the lower limit value of the appropriate range of the cranking speed at the start, and the cranking speed is within the appropriate range. In addition, it is determined whether or not the pass time of the reluctator is too short at the start (whether the cranking speed is not possible at the start), and if the pass time of the reluctator is too short, noise The engine is misfired for failing to measure the regular elapsed time of the reluctator.
[0028]
With this configuration, when noise is mixed in the output of the signal generator at the time of starting, the ignition operation is performed in a state where the cranking speed is insufficient by detecting the cranking speed higher than the actual speed. Thus, the phenomenon that the piston is pushed back when the engine is started can be prevented.
[0029]
In the second start time fire permission / refusal means, the reluctator passage time is set to be shorter than the first determination reference time in a state where the first start time fire permission / rejection means permits the supply of the ignition signal to the ignition circuit. A comparison determination means for performing a comparison determination process for comparing with the second determination reference time, and a comparison determination number determination means for determining the number of times the comparison determination process has been performed. The supply of the ignition signal to the ignition circuit is stopped when it is determined that the time is equal to or less than the determination reference time of 2, and when it is determined by the comparison determination means that the reluctator passing time exceeds the second determination reference time; It is preferable that the ignition circuit is configured to give an ignition signal when the comparison determination process determines that the comparison determination process has been performed n times (n is an integer of 2 or more).
[0030]
Here, the value of n is the engine start when the cranking speed at the start is not insufficient and the output of the signal generator is not mixed with noise that causes an error in measuring the elapsed time of the reluctator. For the number of times that the elapsed time of the reluctator is measured until the rotational speed of the engine reaches the rotational speed Ns / k corresponding to the second determination reference time Ts ′ after the start of the operation, and for the erroneous measurement of the pass time of the reluctor An appropriate value is set in consideration of the number of misfires of the engine that must be allowed when starting the engine in order to prevent erroneous ignition.
[0031]
As described above, if the number of times that the second starting point fire permission / rejection means performs the comparison determination between the reluctator elapsed time and the second determination reference time is limited, after the engine is started, the rotational speed is Before the engine is stabilized, the engine is prevented from misfiring when the engine speed reaches the rotation speed corresponding to the second determination reference time Ts / k, and the engine once started is prevented from stopping. Can do.
[0032]
Note that the process of giving the ignition signal to the ignition circuit by the first and second start time fire permission / refusal means is performed only after the start of the engine until the rotation speed is stabilized, and the second determination reference time Ts. / K is set to a value corresponding to the set speed set near the lower limit of the rotation speed region where the engine rotation is stable, as described above, the second start time fire permission / rejection means There is no need to particularly provide a process of limiting the number of times of performing the comparison determination process with the second determination reference time.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0034]
FIG. 1 shows a hardware configuration example of an embodiment of the present invention. In FIG. 1, 1 is applied to an ignition plug attached to a cylinder of an internal combustion engine when an ignition signal Vi is given. An ignition circuit for generating a high voltage of 2 and 2 is a first polarity pulse signal P1 and a second polarity by detecting a front end side edge and a rear end side edge in a rotating direction of a reluctator provided in a rotor that rotates synchronously with the engine, respectively. The signal generator 3 for generating the pulse signal P2 of 3 is measured as the time when the signal generator 2 generates the pulse signal P1 of the first polarity until the pulse signal P2 of the second polarity is generated as the reluctator passing time ΔT. The timing means for measuring the passage time of the reciprocator, and the ignition timing of the internal combustion engine is detected based on the measured passage time ΔT of the reluctator when the time measurement means measures the passage time of the reluctator when the internal combustion engine is started. A starting point fire signal supplying means for giving an ignition signal to the ignition circuit 1, an ignition timing determining means for determining an ignition timing after the start of the internal combustion engine based on the reciprocator passing time measured by the timing means, and an ignition timing determining means Is a microcomputer for realizing a steady operation time point fire signal supply means for detecting the ignition timing determined by the above and providing an ignition signal to the ignition circuit.
[0035]
More specifically, the illustrated ignition circuit 1 has one end connected to an ignition coil IG having a primary coil W1 and a secondary coil W2 that are grounded at one end, and a non-grounded terminal of the primary coil W1 of the ignition coil. An ignition capacitor Ci, a thyristor Th connected between the other end of the ignition capacitor Ci and the ground with the cathode facing the ground side, and a diode connected to the both ends of the primary coil of the ignition coil with the cathode facing the ground side Capacitor discharge comprising D1, a diode D2 having a cathode connected to the other end of the capacitor Ci, a resistor R1 connected between the gate and cathode of the thyristor Th, and a resistor R2 having one end connected to the gate of the thyristor Th It consists of an expression circuit. A non-grounded terminal of the secondary coil W2 of the ignition coil IG is connected to a non-grounded terminal of a spark plug PL attached to the cylinder of the engine.
[0036]
The anode of the diode D2 is connected to the output terminal of a booster circuit (DC / DC converter) 5 that boosts the output voltage of the battery 4. The diode D2, the primary coil W1 of the ignition coil, and the diode D1 are connected in parallel with the output voltage of the booster circuit 5. Through the circuit, the ignition capacitor Ci is charged to the polarity shown.
[0037]
The signal generator 2 includes a rotor 2A attached to a crankshaft of an internal combustion engine and a pulsar 2B. The illustrated rotor 2 </ b> A includes a rotating body 201 made of a magnetic material having a cylindrical outer peripheral surface, and a relaxor 202 made of an arc-shaped protrusion formed on the outer periphery of the rotating body. When a flywheel magnet generator is attached to the internal combustion engine, the flywheel that constitutes the yoke of the rotor of the generator can be used as the rotating body 201. The pulsar 2B includes, for example, an iron core (not shown) having a magnetic pole portion disposed at a tip thereof so as to face the outer peripheral surface of the rotating body 201 and the reluctor 202, a signal coil 203 wound around the iron core, A permanent magnet (not shown) magnetically coupled to the iron core, and when the magnetic pole portion of the iron core starts to face the front end side edge 202a in the rotation direction of the reluctator 202 (when the edge 202a is detected) ) And the rear edge 202b (when the edge 202b is detected), the first polarity pulse signal P1 and the second polarity pulse signal P1 as shown in FIG. A pulse signal P2 is generated. In the present embodiment, the first polarity is negative and the second polarity is positive.
[0038]
The first polarity pulse signal P1 and the second polarity pulse signal P2 generated by the pulsar 2B pass through the first waveform shaping circuit 6 and the second waveform shaping circuit 7 and the resistors Ra and Rb, respectively, and the port A1 of the microcomputer 3. And A2. The first and second waveform shaping circuits 6 and 7 respectively generate signals having waveforms that can be recognized by the microcomputer when the first polarity pulse signal P1 and the second polarity pulse signal P2 reach the threshold level. It is a circuit to output.
[0039]
The microcomputer 3 includes a CPU, a ROM, a RAM, a timer, and the like, and operates by being supplied with a power supply voltage (for example, 5 V) from a control power supply circuit 8 that outputs a constant DC voltage using the battery 4 as a power supply.
[0040]
The microcomputer 3 executes a program stored in the ROM so as to provide an ignition control unit such as a time measuring means for measuring the elapsed time of the retractor, a starting time fire signal supplying means, an ignition timing determining means, and a steady operation time fire signal supplying means. A function realization means necessary for the configuration is realized.
[0041]
The time measuring means for measuring the elapsed time of the reluctor is a means for measuring a time from when the signal generator 2 generates the pulse signal P1 of the first polarity to the generation of the pulse signal P2 of the second polarity as the reluctator passing time, When the pulse signal P1 of the first polarity is generated, the timer in the microcomputer is reset, and at the same time, the timer starts a timing operation, and when the pulse signal P2 of the second polarity is generated, the measured value of the timer is read.
[0042]
The ignition timing determining means is means for determining an ignition timing after the internal combustion engine is started, and this means calculates the ignition timing of the engine with respect to a predetermined control condition including the engine speed. The ignition timing is calculated in the form of time Ti (see FIG. 1A) from the timing t1 when the first polarity pulse signal is generated to the ignition timing ti. In this specification, this time Ti is referred to as a measurement time for ignition timing detection. During the ignition timing detection measurement time Ti, the engine rotates at the instantaneous rotational speed from the crank angle position θ1 corresponding to the generation timing t1 of the first polarity pulse signal to the crank angle position θi corresponding to the ignition timing ti. It takes time to complete.
[0043]
Usually, the calculation of the ignition timing is a map (stored in the ROM) that gives the relationship between the ignition timing and data including information on the engine speed detected immediately before the calculation and other necessary conditions (if any). This is performed by interpolation using the data read from (1).
[0044]
As the data including the information on the rotational speed of the internal combustion engine, the above-mentioned reluctator passing time ΔT may be used. The time required for the engine to make one revolution (for example, after the generation of the pulse signal P1 of each first polarity). The time until the first polarity pulse signal P1 is generated again may be used.
[0045]
When using the reluctator passage time ΔT as data indicating the engine rotation speed, if the polar arc angle of the reluctator is α and the multiplication symbol is *, the ignition angle detection measurement time Ti and the crank angle position θi corresponding to the ignition timing ti There is the following relationship.
[0046]
Ti = (θi / α) ΔT (3)
The steady operation time fire signal supply means is means for detecting the ignition timing determined by the ignition timing determination means and for providing an ignition signal to the ignition circuit. For example, the signal generator 2 has the first polarity. Ignition timer setting means for setting the ignition timing detection measurement value Ti to the ignition timer when the pulse signal P1 is generated, and the potential of the port A3 when the ignition timer completes the measurement of the measurement value Ti. Level) and ignition signal output means for giving an ignition signal to the thyristor Th of the ignition circuit.
[0047]
In the ignition device shown in FIG. 1, when the potential of the port A3 of the microcomputer 3 is set to the H level and the ignition signal Vi is given to the ignition circuit 1, the thyristor Th is turned on, so that it accumulates in the ignition capacitor CI. The charged charges are discharged through the thyristor Th and the primary coil W1 of the ignition coil. Due to this discharge, a high voltage is induced in the primary coil of the ignition coil, and this voltage is boosted by the turn ratio between the primary and secondary of the ignition coil, and a high voltage for ignition is induced in the secondary coil W2 of the ignition coil. Since this high voltage is applied to the spark plug PL, spark discharge occurs in the spark plug, and the engine is ignited.
[0048]
During steady operation of the engine where the rotational speed of the internal combustion engine is stable, it is possible to detect the ignition timing calculated using the ignition timer as described above. However, when the internal combustion engine is started, the rotational speed of the crankshaft varies finely with changes in the stroke of the engine, so that it is difficult to detect the ignition timing using an ignition timer. Therefore, until the engine rotational speed is stabilized, the ignition device control mode is set to the start mode, and the start point fire signal supply means does not use the ignition timer but at a predetermined timing as the ignition timing at the start. An ignition signal is given to the ignition circuit at the corresponding crank angle position.
[0049]
The start time fire signal supply means is based on the measured retractor passage time ΔT every time the time measurement means measures the reluctor passage time ΔT until the rotation speed is stabilized after the start of the internal combustion engine. Means for detecting the ignition timing at the start of the internal combustion engine and supplying the ignition signal Vi to the ignition circuit 1. In the present invention, this start time fire signal supply means has at least the following means.
[0050]
(A) The reluctator passage time ΔT is compared with the first determination reference time Ts every time the time measuring means for measuring the reluctator passage time measures the reluctor passage time, and the reluctor passage time ΔT is the first determination reference. The supply of the ignition signal to the ignition circuit 1 is permitted when the time is shorter than the time Ts, and the ignition circuit 1 is prohibited from being given an ignition signal when the reluctator passage time ΔT exceeds the first determination reference time Ts. The first starting time fire permission means.
[0051]
(B) A second determination reference time in which the reluctator passage time ΔT is set to be shorter than the first determination reference time Ts in a state where supply of the ignition signal to the ignition circuit 1 is permitted by the starting point fire permission / rejection means. An ignition signal is supplied to the ignition circuit when the pass time of the retractor exceeds the second determination reference time as compared with Ts / k, and when the pass time of the relaxor is equal to or less than the second determination reference time, Second start time fire permission / rejection means for prohibiting the supply of the ignition signal.
[0052]
The first start-time fire permission / rejection means is provided for determining whether or not the cranking speed at the start is insufficient, and when it is determined that the cranking speed is not insufficient. Only allow the ignition signal to be given to the ignition circuit.
[0053]
Accordingly, the first determination reference time Ts is set equal to the reluctator elapsed time corresponding to the lower limit value Ns of the appropriate range of the cranking speed at the start of the engine. For example, when a cranking speed of 150 [rpm] or more is required at the time of the first ignition at the time of starting in order to prevent a phenomenon in which the piston is pushed back when the engine is started, the first determination reference time is set to 150 [ rpm] is set to a relapser elapsed time (= 33333 μs).
[0054]
FIG. 2B shows a case where the gap between the rotor of the signal generator 2 and the pulsar fluctuates due to mechanical vibration generated when the engine is started, and noise is mixed in the output of the pulsar. An example of a signal waveform is shown. When noise is mixed in the output of the signal generator in this way, after the pulse signal P1 having the normal first polarity is generated, when the peak of the first polarity of the noise exceeds the threshold value, the time for measuring the pass time of the reluctor is measured. The time measured by the means is read into the microcomputer as the reluctator passage time ΔT ′. Therefore, the microcomputer passes through the reluctator passing time as being shorter than the actual time. When such a state occurs, the cranking speed is detected to be higher than the actual speed, so that it is determined that the cranking speed is not insufficient although the cranking speed is insufficient. If the ignition operation is performed in such a state, the piston may not be able to exceed the top dead center due to a lack of inertia force, and the engine may fail to start.
[0055]
The second start-time fire permission / refusal means, when noise is generated between the time when the signal generator generates the normal first polarity pulse signal and before the generation of the normal second polarity pulse signal, This is provided to prevent the cranking speed from being detected as being higher than the actual speed, so that it is determined that the cranking speed is not insufficient even though the cranking speed is insufficient. When it is determined that the ignition signal is short, the supply of the ignition signal to the ignition circuit is stopped.
[0056]
Accordingly, the second determination reference time Ts ′ is set to be equal to the retractor passing time corresponding to a value near the lower limit value of the cranking speed that cannot be obtained at the normal start. For example, when starting by human power, if a cranking speed that is four times the lower limit value Ns of the appropriate range of the cranking speed Ns (150 [rpm] in the above example) 4 * Ns or more cannot be obtained Then, the second determination reference time is set to 8333 μs (= 33333/4 μs), which is a reluctator elapsed time corresponding to 4 * Ns (= 600 [rpm]).
[0057]
In general, when a cranking speed equal to or higher than a speed k * Ns that is k times the lower limit value Ns of the appropriate range of the cranking speed is not obtained when the engine is started, the second determination reference time Ts ′ is Ts / k or less. Set to. Note that k is an integer or decimal number exceeding 1.
[0058]
That is, in the present invention, when it is determined that the reciprocator passage time is shorter than the first determination reference value corresponding to the lower limit value of the appropriate range of the cranking speed at the start, and the cranking speed is within the appropriate range. In addition, it is determined whether the pass time of the reluctator is not too short at the start (whether the cranking speed is not possible at the start), and if the pass time of the reluctator is too short, it is normalized by noise. The engine is misfired for failing to measure the elapsed time.
[0059]
With this configuration, when noise is mixed in the output of the signal generator at the time of starting, the ignition operation is performed in a state where the cranking speed is insufficient by detecting the cranking speed higher than the actual speed. Thus, the phenomenon that the piston is pushed back when the engine is started can be prevented.
[0060]
When configured as described above, the engine speed increases until the end of the start mode for determining the timing at which the ignition signal is supplied by the start point fire signal supply means, and the normally-detected time for the reluctator to pass is detected. When the state becomes shorter than the second determination reference time Ts ′, the ignition signal is not given to the ignition circuit, and the engine misfires.
[0061]
In order to prevent such a situation from occurring, the second start time fire permission / refusal means is configured such that the first start time fire permission / rejection means permits the supply of the ignition signal to the ignition circuit in a state permitted by the first start time fire permission / rejection means. Comparison determination means for performing a comparison determination process for comparing the first determination reference time with a second determination reference time set shorter than the first determination reference time, and comparison determination number determination means for determining the number of times the comparison determination process has been performed. In addition, the supply of the ignition signal to the ignition circuit is stopped when the comparison determining means determines that the reluctator passing time is equal to or shorter than the second determination reference time, and the reluctor passing time is determined by the comparison determining means to the second determination. An ignition signal is provided to the ignition circuit when it is determined that the reference time has been exceeded and when the comparison determination process is determined to be performed n times (n is an integer of 2 or more) by the comparison determination number determination means. Preferably formed.
[0062]
Here, the value of n is the engine start when the cranking speed at the start is not insufficient and the output of the signal generator is not mixed with noise that causes an error in measuring the elapsed time of the reluctator. The time elapsed after the start of the operation is estimated to be performed until the rotational speed of the engine reaches the rotational speed Ns / k (k is a real number exceeding 1) corresponding to the second determination reference time Ts ′. Set it to an appropriate value in consideration of the predicted number of measurements and the number of misfires that must be allowed to prevent misignition due to erroneous determination of the cranking speed due to noise during startup. Keep it. For example, if the start operation is performed at a sufficient cranking speed and noise that causes an error in the measurement of the reluctator elapsed time is not mixed in the output of the signal generator, This is a case where the engine speed is expected to reach the rotation speed Ns / k corresponding to the second determination reference time Ts ′ at the stage where the measurement is performed twice (when the second ignition is performed). However, as shown in FIG. 2B, the measurement of the pass-through time of the reluctator due to the generation of noise between the generation of the first first polarity pulse signal P1 and the generation of the second polarity pulse signal is possible. If it is expected to be performed at least four times (when it is necessary to allow at least four engine misfires), n = 5 is set.
[0063]
In the example shown in FIG. 2B, after the start operation is started, the first regular pulse signal P1 having the first polarity is generated and the pulse signal P2 having the regular second polarity is generated. The peak of the first polarity of noise exceeding the threshold value has occurred three times. In this case, the reluctator elapsed time ΔT is measured four times during the period from the generation of the pulse signal P1 to the generation of P2, but both are shorter than the second determination reference time Ts ′. The ignition signal supply is stopped. After that, when the crankshaft makes one revolution, the pulse signal P1 having the first polarity and the pulse signal P2 having the second polarity are generated one after another. During the generation of these signals, noise exceeding the threshold value is generated. Since it did not occur, an ignition signal is given to the ignition circuit when the pulse signal P2 of the second polarity is generated.
[0064]
As described above, by providing means for limiting the number of times that the second start-time fire permission / refusal means performs the comparison determination between the reluctator elapsed time and the second determination reference time, the second determination reference time is set. Even when the time corresponding to the relatively low rotational speed is set, the engine is operated when the rotational speed of the engine reaches the rotational speed corresponding to the second determination reference time Ts ′ while the operation of the engine is in the start mode. Can be prevented from being misfired, so that the degree of freedom in setting the second determination reference time can be increased.
[0065]
As described above, when the second start time fire permission / refusal means is configured so as to limit the number of times of performing the comparison determination between the reluctator elapsed time and the second determination reference time, the rotational speed of the engine after the start of the engine is FIG. 3 shows a flowchart showing an algorithm of an interrupt routine that is executed by the microcomputer every time the signal generator 2 generates a pulse signal of the second polarity until it stabilizes.
[0066]
In the case of this algorithm, first, in step 1, the reluctator passing time ΔT measured by the measuring means (timer) for measuring the passing time of the reluctor is stored in the RAM. Next, in Step 2, the reluctator passage time ΔT is compared with the first determination reference time Ts. As a result, if it is determined that ΔT <Ts is not satisfied (the cranking speed at the start operation is insufficient), Step 3 Proceeding to prohibits the ignition circuit from being given an ignition signal and causes the engine to misfire.
[0067]
When it is determined in step 2 that ΔT <Ts (the cranking speed is not insufficient), the process proceeds to step 4 and the determination process in step 2 is already set n (n is an integer of 2 or more) times. It is determined whether or not the above has been executed. As a result, when it is determined that the number of executions of step 2 has not reached n, the process proceeds to step 5 to determine whether or not the relationship ΔT> Ts / k (k is an integer or decimal number exceeding 1) is established. judge. As a result, when the relationship ΔT> Ts / k is established, the routine proceeds to step 6 where the potential of the port A3 is set to the H level to give the ignition circuit 1 the ignition signal Vi to perform the ignition operation. Thereafter, if there is further necessary processing, the processing is performed in step 7 and thereafter, and the process returns to the main routine.
[0068]
When it is determined in step 5 that the relationship ΔT> Ts / k is not established (the time when the reluctator passes is too short at the start of the engine and the rotational speed of the crankshaft is too fast at the start) Then, it is determined that the measurement of the elapsed time of the reluctator performed this time is based on the noise signal, and the routine proceeds to step 3 where the engine is misfired.
[0069]
If it is determined in step 5 in FIG. 3 that the number of executions of step 2 has reached n, step 6 is performed without determining whether the relationship ΔT> Ts / k is established. Then, the ignition signal is supplied to the ignition circuit to perform the ignition operation.
[0070]
In the case of the algorithm shown in FIG. 3, the signal generator generates a pulse signal of the first polarity by a timer provided in the microcomputer for measuring the pass-through time ΔT and step 1 in FIG. The measuring means for measuring the passage time of the reluctor is configured to measure the time from when the pulse signal of the second polarity is generated to the time when the pulse signal of the second polarity is generated.
[0071]
Further, every time the time measuring means measures the reluctator passage time ΔT according to step 2 in FIG. 3, the measured reluctator passage time ΔT is compared with the first determination reference time Ts, and the reluctator passage time becomes the first time. When the reference signal is shorter than the determination reference time, supply of the ignition signal to the ignition circuit is permitted, and when the reluctator passage time exceeds the first determination reference time, the ignition circuit is prohibited from being given an ignition signal. 1 start time fire permission / rejection means is configured.
[0072]
Further, in step 5 in FIG. 3, the second time when the reluctator passage time is set shorter than the first determination reference time in a state where the supply of the ignition signal to the ignition circuit is permitted by the first start time fire permission / rejection means. The comparison determination means for performing the comparison determination process for comparison with the determination reference time is configured, and the comparison determination number determination means for determining the number of times the comparison determination process has been performed is configured by Step 4. The ignition signal to the ignition circuit when the comparison determination unit determines that the reluctator passage time is equal to or shorter than the second determination reference time by the comparison determination unit, the comparison determination number determination unit, and steps 3 and 6. Is stopped, and the comparison judgment means determines that the reluctator passing time exceeds the second judgment reference time and the comparison judgment number judgment means performs n comparison judgment processes (n is an integer of 2 or more). A second start time fire permission / refusal means is provided that gives an ignition signal to the ignition circuit when it is determined that the above has been performed.
[0073]
Note that the process of supplying the ignition signal to the ignition circuit by the first and second start-time fire permission / refusal means is performed only until the rotational speed becomes stable after the start of the engine, and the second determination reference time Ts. / K is set to a value corresponding to the set speed set near the lower limit of the speed range where the engine rotation is stable, as described above, the second elapsed start-time fire permission / rejection means is provided with the elapsed time ΔT It is not necessary to provide a process for limiting the number of times that the comparison determination process between the second determination reference time Ts / k and the second determination reference time Ts / k is performed.
[0074]
In the above example, it is determined whether or not the reluctator passage time ΔT is shorter than the first determination reference time Ts, and immediately when it is determined that ΔT <Ts, Step 4 is performed to determine the number of comparison determinations. However, as shown in FIG. 4, step 2 ′ is inserted between step 2 and step 4 in FIG. After determining whether or not it is Ts, in step 2 ′, the reluctator passage time ΔT is set shorter than the first determination reference time Ts and longer than the second determination reference time Ts / k. If it is determined in step 2 ′ that ΔT> Ts ′, the engine may be immediately misfired without shifting to step 4. Here, the third determination reference time Ts ′ is set to a rotation speed suitable for confirming that the engine has been started after starting the engine. For example, when Ts is set to a value corresponding to 150 [rpm] and Ts / k is set to 600 [rpm], Ts ′ is set to about 1000 [rpm].
[0075]
If comprised in this way, when starting of an engine is completed and the rotational speed exceeds 1000 [rpm], it can prevent that the process after step 4 is performed wastefully.
[0076]
In the above description, when the microcomputer 3 recognizes the pulse signal P2 having the second polarity at the time of starting the engine, the port A3 of the microcomputer is set to the H level to give an ignition signal to the ignition circuit 1. It is also possible to provide an ignition signal from the signal generator 2 to the ignition circuit 1 through a hardware circuit. However, in the case of such a configuration, it is necessary to make the engine misfire when necessary, or to prevent the ignition circuit from being given an ignition signal at the ignition timing at the start after the start of the engine is completed. Therefore, it is necessary to provide means for preventing the ignition signal from being applied to the ignition circuit 1 by the output (P2) of the signal generator 2.
[0077]
For example, as shown in FIG. 5, a circuit for supplying a pulse signal P2 having the second polarity generated by the signal generator 2 to the thyristor Th of the ignition circuit as a starting ignition signal through the diode D3 and the resistor R2, A circuit that supplies an ignition signal during steady operation from the port A3 of the computer 3 to the thyristor Th through the diode D4 and the resistor R2 may be employed.
[0078]
In the case of such a configuration, for example, when a drive signal is given from the port A4 of the microcomputer, the switch 9 becomes conductive and bypasses the pulse signal P2 of the second polarity from the ignition circuit 1 for the bypass switch 9. When the engine is misfired as necessary at the time of start-up, and when the engine 9 is started, and when the operation mode is shifted to the normal operation mode, the switch 9 is turned on, so that the ignition circuit 1 is turned on. The supply of the ignition signal can be stopped.
[0079]
In the example shown in FIG. 5, the bypass switch 9 is constituted by the NPN transistor TR1 whose emitter is grounded, collector is connected to the anode of the diode D3, and base is connected to the port A4 of the microcomputer 3. When the potential of the port A4 is set to the H level, the transistor TR1 is turned on to prevent the pulse signal P2 from being applied as an ignition signal to the ignition circuit.
[0080]
In the above description, only the interrupt routine executed when the signal generator generates the pulse signal of the second polarity is shown. However, in the main routine of the program executed by the microcomputer, the reluctator passing time ΔT is Calculations are performed to configure function realizing means such as ignition timing calculation means for calculating the ignition timing during steady operation of the engine. In addition to the interrupt routine and the main routine shown in FIG. 3 or FIG. 4, when the signal generator generates a pulse signal of the first polarity during steady operation of the engine, the ignition timer detection measurement time Ti is set in the ignition timer. An interrupt routine for configuring an ignition timer setting means for setting and starting the measurement, and an ignition for outputting an ignition signal with the potential of the port A3 set to H level when the ignition timer measures the ignition timing detection measurement time Ti An interrupt routine for configuring a steady-time fire signal supply means including an interrupt routine for configuring a signal output means is further provided. These configurations are the same as those used in conventional ignition devices. Since it is good, detailed description of each is omitted.
[0081]
In the example shown in FIG. 1, the ignition capacitor Ci is connected in series with the primary coil of the ignition coil, and the charging current of the ignition capacitor is configured to flow through the primary coil of the ignition coil. In FIG. 1, it is possible to adopt a configuration in which the positions of the ignition capacitor Ci and the thyristor Th are interchanged.
[0082]
In the above example, the power supply unit for charging the ignition capacitor is configured by the battery and the booster circuit for boosting the voltage of the battery. However, the exciter coil provided in the magnet generator attached to the internal combustion engine is used as a power source for ignition. The capacitor may be charged, or the ignition capacitor may be charged using a power supply circuit including a power generation coil provided in the magnet generator and a chopper circuit that boosts the output of the power generation coil as a power source.
[0083]
The ignition circuit 1 is not limited to a capacitor discharge type circuit, and the present invention can also be applied to a case where a current interruption type ignition circuit is used.
[0084]
【The invention's effect】
As described above, according to the present invention, at the time of start-up, the elapsed time of the relaxor is compared with the first determination reference time, and the ignition is permitted when the elapsed time of the relaxor is shorter than the first determination reference time. The first start-time fire permission / refusal means for prohibiting ignition when the elapsed time is equal to or greater than the first determination reference time, and the reluctator elapsed time is set to the first time when ignition is permitted by the first ignition permission / rejection means. An ignition signal is given to the ignition circuit when the elapsed time of the relaxor is longer than the second determination reference time compared to the second determination reference time shorter than the first determination reference time, and the reluctator elapsed time is the second determination Since the second start time point fire permission / refusal means for prohibiting the supply of the ignition signal when the reference time or less is provided, the ignition is prohibited when it is detected at the start that the elapsed time of the reluctor is too short. Generate signal at start When noise is mixed in the output of the device, the cranking speed is detected to be higher than the actual speed, so that the ignition operation is performed in a state where the cranking speed is insufficient, and the piston is pushed back when the engine is started. The phenomenon can be prevented from occurring.
[0085]
Further, in the present invention, when the second starting point fire permission / refusal means is provided with means for limiting the number of times of performing the comparison determination between the reluctator elapsed time and the second determination reference time, the second determination reference time Is set to a time corresponding to a relatively low rotational speed, the rotational speed of the engine corresponds to the second determination reference time after the start operation of the engine is started until the rotational speed is stabilized. Since it is possible to prevent the engine from misfiring when reaching the value, the degree of freedom of the setting range of the second determination reference time can be increased.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a configuration example of hardware used in an embodiment of the present invention.
FIGS. 2A and 2B are waveform diagrams showing the waveforms of pulse signals generated by the signal generator when the engine is started in the ignition device of FIG. 1;
FIG. 3 is a flowchart showing an example of an algorithm of a program executed by a microcomputer to constitute the first start time fire permission / rejection means and the second start time fire permission / rejection means in the embodiment shown in FIG. 1; is there.
FIG. 4 shows another example of an algorithm of a program executed by the microcomputer to constitute the first start time fire permission / rejection means and the second start time fire permission / rejection means in the embodiment shown in FIG. It is a flowchart.
FIG. 5 is a circuit diagram showing a configuration example of hardware used in another embodiment of the present invention.
FIG. 6 is a flowchart showing an algorithm of an interrupt routine executed when the engine is started in a conventional ignition device.
FIGS. 7A and 7B are waveform diagrams showing waveforms of pulse signals generated by the signal generator in the ignition device targeted by the present invention. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ignition circuit, Ci ... Ignition capacitor, IG ... Ignition coil, Th ... Thyristor, Vi ... Ignition signal, 2 ... Signal generator, P1 ... First polarity pulse signal, P2 ... Second polarity pulse signal, 3 ... microcomputer, 4 ... battery, 5 ... boost circuit.

Claims (2)

An ignition circuit that generates a high voltage to be applied to an ignition plug attached to a cylinder of an internal combustion engine when an ignition signal is given, and a front end in a rotational direction of a relucter provided in a rotor that rotates synchronously with the internal combustion engine A signal generator for generating a first polarity pulse signal and a second polarity pulse signal when a side edge and a rear end edge are detected, respectively, and the signal generator generates the first polarity pulse signal. Measuring time for measuring the passage time of the second polarity from the start of the internal combustion engine until the rotation speed is stabilized, A starting point fire signal supplying means for detecting a predetermined ignition timing as an ignition timing at the start of the internal combustion engine and supplying an ignition signal to the ignition circuit; and a rotational speed of the internal combustion engine is stable. Ignition timing determining means for determining the ignition timing at the time of steady operation thereafter, and steady operation time point fire signal supply means for detecting the ignition timing determined by the ignition timing determining means and providing an ignition signal to the ignition circuit. In the internal combustion engine ignition device provided,
The starting point fire signal supplying means is
Each time the time measuring means measures the reluctator passage time, the measured reluctator passage time is compared with the first determination reference time, and when the reluctator passage time is shorter than the first determination reference time, the ignition circuit is supplied. First start time fire permission / rejection means for permitting the supply of the ignition signal, and prohibiting the ignition circuit from being given an ignition signal when the reluctator passage time exceeds the first determination reference time;
A second determination criterion in which the pass-through time of the reluctator is set shorter than the first determination reference time in a state where the supply of the ignition signal to the ignition circuit is permitted by the first starting time fire permission / rejection means. An ignition signal is supplied to the ignition circuit when the pass time of the relaxor exceeds the second determination reference time as compared to time, and when the pass time of the relaxor is equal to or less than the second determination reference time, A second start time fire permission / refusal means for prohibiting the supply of the ignition signal to the ignition circuit;
An ignition device for an internal combustion engine, comprising: An ignition circuit that generates a high voltage to be applied to an ignition plug attached to a cylinder of an internal combustion engine when an ignition signal is given, and a front end in a rotational direction of a relucter provided in a rotor that rotates synchronously with the internal combustion engine A signal generator for generating a first polarity pulse signal and a second polarity pulse signal when a side edge and a rear end edge are detected, respectively, and the signal generator generates the first polarity pulse signal. Measuring time for measuring the passage time of the second polarity from the start of the internal combustion engine until the rotation speed is stabilized, A starting point fire signal supplying means for detecting a predetermined ignition timing as an ignition timing at the start of the internal combustion engine and supplying an ignition signal to the ignition circuit; and a rotational speed of the internal combustion engine is stable. Ignition timing determining means for determining the ignition timing at the time of steady operation thereafter, and steady operation time point fire signal supply means for detecting the ignition timing determined by the ignition timing determining means and providing an ignition signal to the ignition circuit. In the internal combustion engine ignition device provided,
The starting point fire signal supplying means is
When the time measuring means measures the reluctator passing time each time the reluctator passing time is compared with the first determination reference time, the reluctator passing time is determined to be shorter than the first determination reference time. A first start that permits the supply of an ignition signal to the ignition circuit and prohibits the ignition circuit from being given an ignition signal when it is determined that the reluctator passage time exceeds the first determination reference time. Ignition ignition permission means,
A second determination reference time in which the reluctator passage time is set to be shorter than the first determination reference time in a state where the supply of an ignition signal to the ignition circuit is permitted by the first start time fire permission / refusal means; And a comparison determination means for determining the number of times that the comparison determination process has been performed, and the second determination by the comparison determination means. When it is determined that it is less than a reference time, the supply of the ignition signal to the ignition circuit is stopped, and when the pass through the reluctator is determined to exceed the second determination reference time by the comparison determination means And a second start time ignition that gives an ignition signal to the ignition circuit when it is determined by the comparison determination number determination means that the comparison determination process has been performed n times (n is an integer of 2 or more). And means,
An ignition device for an internal combustion engine, comprising:

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