JP2005016430A - Control device for vehicle driving internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a function to quickly increase an exhaust temperature to a target exhaust temperature for obtaining a sufficient engine output after an engine is started, in a control device for a vehicle driving internal combustion engine to perform control to correct ignition timing to a delay side in the case that the exhaust temperature is lower. <P>SOLUTION: This control device is provided with a mode selecting switch 6 to select an exhaust temperature control mode and a steady operation period control mode, and an exhaust temperature increasing ignition control means 15B to control the ignition timing of the internal combustion engine so that when the exhaust temperature control mode is selected by the mode selecting switch, the exhaust temperature of the internal combustion engine 10 is increased to the target exhaust temperature set to a value suitable for a vehicle traveling period. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an internal combustion engine for driving a vehicle provided with means for controlling the ignition timing of the engine in accordance with the exhaust gas temperature.
[0002]
[Prior art]
In an internal combustion engine, in order to improve its output, it is necessary to advance the ignition timing of the engine as the rotational speed increases in a predetermined rotational speed region.
[0003]
Further, in an internal combustion engine, it is attempted to improve the output by increasing the charging efficiency by utilizing the inertia effect of the gas flow in the exhaust pipe. Since the inertia effect of the gas flow in the exhaust pipe is affected by the exhaust temperature, in order to improve the output of the engine, the ignition timing according to the exhaust temperature is used so that the inertia effect can be used effectively. Is preferably controlled.
[0004]
Therefore, as shown in Patent Document 1 and Patent Document 2, the ignition timing of the engine is controlled with respect to the rotational speed and also with respect to the exhaust temperature.
[0005]
The control device described in Patent Document 1 performs control to advance the ignition timing as the engine speed increases, and corrects the ignition timing to the delay side as the exhaust temperature decreases, The lower the temperature, the larger the correction amount to the ignition timing delay side.
[0006]
In the control device described in Patent Document 2, a plurality of ignition patterns that provide a relationship between the engine speed and the ignition timing are prepared, and a predetermined ignition pattern is set according to the detected exhaust gas temperature. By selecting, the engine performance is improved.
[0007]
[Patent Document 1]
Japanese Patent Publication No. 7-37767
[0008]
[Patent Document 2]
US Pat. No. 6,237,566
[0009]
[Problems to be solved by the invention]
As shown in Patent Document 1 and Patent Document 2, in an internal combustion engine that controls the ignition timing as the exhaust gas temperature decreases, if the exhaust gas temperature is low before starting the vehicle, the ignition timing is Since the correction is made to the delay side, the engine output cannot be sufficiently obtained immediately after starting, and the acceleration performance of the vehicle cannot be avoided.
[0010]
Especially when the vehicle is a snowmobile used in cold regions, the exhaust temperature is low for a while after starting the engine, so the acceleration performance drops to a level that cannot be ignored when starting the vehicle, and the driving feeling is poor. It was pointed out that
[0011]
An object of the present invention is to drive the vehicle so that the acceleration performance of the vehicle can be improved by increasing the exhaust temperature to a target exhaust temperature suitable for steady operation before starting the vehicle. The present invention provides a control device for an internal combustion engine.
[0012]
[Means for Solving the Problems]
The present invention controls an internal combustion engine for driving a vehicle comprising an exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives the vehicle, and an ignition control means for controlling the ignition timing of the internal combustion engine with respect to various control conditions. It is intended for the apparatus, and the ignition control means is configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust gas temperature detected by the exhaust gas temperature sensor is low.
[0013]
In the present invention, the mode selection means for selecting the exhaust temperature control mode and the steady operation mode control mode, and when the exhaust temperature control mode is selected by the mode selection means, the exhaust temperature is set to a value suitable for driving the vehicle. There is provided an exhaust temperature raising ignition control means for controlling the ignition timing of the internal combustion engine so as to raise the target exhaust gas temperature and keep the exhaust gas temperature in the vicinity of the target exhaust gas temperature.
[0014]
When configured as described above, before starting the vehicle, the exhaust temperature control mode is selected by the mode selection means, thereby raising the exhaust temperature of the engine to a target exhaust temperature (for example, 500 ° C.) suitable for steady operation. Therefore, the acceleration performance of the engine when starting the vehicle can be improved.
[0015]
In an internal combustion engine, if the ignition timing is delayed, the exhaust temperature increases, and if the ignition timing is advanced, the exhaust temperature decreases. Therefore, in order to control the exhaust gas temperature so as to keep the target exhaust gas temperature, the ignition timing may be delayed or advanced according to the exhaust gas temperature. Since there is a delay before it appears as a change, controlling the ignition timing to be retarded or advanced according to the current value of the exhaust temperature can keep the exhaust temperature stable around the target exhaust temperature. difficult.
[0016]
Therefore, in the present invention, the exhaust temperature sampling means for sampling the exhaust temperature detected by the exhaust temperature sensor at regular time intervals, the exhaust temperature Txn newly sampled by the exhaust temperature sampling means, and a value suitable for vehicle travel The difference ΔTxn between the target exhaust gas temperature Ts set to 1 and the difference ΔTxn−1 between the exhaust gas temperature Txn−1 sampled a predetermined time ago and the target exhaust gas temperature Ts, and constants α1 and α2 (α2> α1). A judgment value calculating means for calculating a value of the judgment value X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1) is provided, and the ignition for raising the exhaust temperature is controlled so as to control the ignition timing of the internal combustion engine according to the judgment value X The control means is configured.
[0017]
In this case, the exhaust temperature rise ignition control means is the most delayed ignition timing in the steady operation when the determination value X is negative when the exhaust temperature control mode is selected by the mode selection means. A second ignition in which the first ignition timing is delayed by a set angle further than the minimum advance ignition timing during steady operation, and the ignition timing is advanced from the first ignition timing when the determination value X is positive. The ignition timing of the internal combustion engine is controlled according to the determination value so as to be the timing.
[0018]
The determination value X is a numerical value indicating how much the exhaust temperature has approached the target exhaust temperature when the exhaust temperature is changed toward the target exhaust temperature, and the target value from the state where the exhaust temperature is lower than the target exhaust temperature. In the process of approaching the exhaust temperature, the absolute value decreases as the difference between the exhaust temperature and the target exhaust temperature decreases, and its sign changes from a negative value to a positive value before the exhaust temperature reaches the target exhaust temperature. Is reversed.
[0019]
Accordingly, as described above, when the determination value X is a negative value, the ignition timing is set as the first ignition timing, and when the determination value X becomes a positive value, the ignition timing is advanced from the first ignition timing. By switching to the angled second ignition timing, when the exhaust gas temperature is low, the ignition timing can be greatly retarded to rapidly increase the exhaust gas temperature toward the target exhaust gas temperature. When the exhaust gas temperature approaches, the ignition timing is advanced by waiting for the exhaust gas temperature to reach the target exhaust gas temperature and predicting that the exhaust gas temperature will soon exceed the target exhaust gas temperature from the reversal of the sign of the judgment value X Thus, the exhaust temperature can be prevented from greatly exceeding the target exhaust temperature. When the ignition timing is switched to the second ignition timing, the exhaust temperature gradually decreases. However, in the process in which the exhaust temperature decreases, the sign of the determination value becomes positive when the exhaust temperature falls below the target exhaust temperature to some extent. Since it changes negatively, the ignition timing can be delayed to the first ignition timing before the exhaust temperature significantly decreases, and the decrease in the exhaust temperature can be suppressed.
[0020]
Therefore, according to the present invention, it is possible to perform control to keep the exhaust temperature near the target exhaust temperature while suppressing the temperature fluctuation range near the target exhaust temperature to a small range.
[0021]
The values of the constants α1 and α2 are determined experimentally by looking at the exhaust temperature control result. The first ignition timing is appropriate, for example, at a timing corresponding to a crank angle position delayed by 30 ° from the top dead center position of the engine (crank angle position when the piston reaches the top dead center in the compression stroke). As the second ignition timing, a timing corresponding to a crank angle position delayed by 5 ° from the top dead center position of the engine is appropriate.
[0022]
In the above configuration, the determination value calculation means is configured to calculate the determination value X using the calculation formula X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1), and the ignition timing when the determination value X is negative. Is the first ignition timing that is further delayed by the set angle than the minimum advance ignition timing during steady operation, which is the most delayed ignition timing during steady operation, and the ignition timing is the first when the determination value X is positive. Is set to a second ignition timing advanced from the ignition timing of the exhaust temperature Txn, and the exhaust gas temperature Txn newly sampled by the exhaust gas temperature sampling means and the target exhaust gas temperature Ts set to a value suitable for vehicle travel It is determined from the difference ΔTxn, the difference ΔTxn−1 between the exhaust temperature Txn−1 sampled a certain time ago and the target exhaust temperature Ts, and the constants α1 and α2 (α2> α1). When the determination value calculation means is configured to calculate the constant value X = −α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn), and the determination value X is positive when the exhaust temperature control mode is selected. The ignition timing is a first ignition timing that is further delayed by a set angle than the minimum advance ignition timing during steady operation, which is the most delayed ignition timing during steady operation, and the ignition timing is determined when the determination value X is negative. The exhaust gas temperature raising ignition control means may be configured to have a second ignition timing that is advanced from the first ignition timing.
[0023]
The determination value X calculated as described above becomes smaller as the difference between the exhaust temperature and the target exhaust temperature becomes smaller in the process where the exhaust temperature approaches the target exhaust temperature from a state where the exhaust temperature is lower than the target exhaust temperature. The sign is inverted from a positive value to a negative value before the exhaust temperature reaches the target exhaust temperature.
[0024]
Therefore, when the determination value X is a positive value, the ignition timing is set as the first ignition timing, and when the determination value X becomes a negative value, the second ignition timing is advanced from the first ignition timing. By switching to the ignition timing, it is possible to perform control to keep the exhaust temperature at the target exhaust temperature while suppressing the temperature fluctuation range near the target exhaust temperature to a small range, as described above.
[0025]
When the internal combustion engine is provided to drive the vehicle via an automatic clutch, when the exhaust temperature reaches the target exhaust temperature during the process of increasing the exhaust temperature, the engine output May increase and the rotational speed may exceed the power transmission start rotational speed of the automatic clutch, and the vehicle may start.
[0026]
In order to prevent such a situation from occurring, when the vehicle is driven by an internal combustion engine via an automatic clutch, the rotational speed of the internal combustion engine is controlled by the automatic clutch while the exhaust gas temperature control mode is selected by the mode selection means. Overspeed control that limits the rotational speed of the internal combustion engine to below the set speed by misfiring the internal combustion engine or delaying the ignition timing of the internal combustion engine when a set speed set near the power transmission start rotational speed is reached Preferably further means are provided.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0028]
FIG. 1 shows a hardware configuration example of an internal combustion engine ignition device whose ignition timing is controlled by a control device according to the present invention. The present invention can be applied regardless of the number of cylinders of the internal combustion engine, but in this example, the number of cylinders of the internal combustion engine is 2. The present invention can be applied to both a two-cycle engine and a four-cycle engine. In this embodiment, the internal combustion engine is a two-cycle engine.
[0029]
In FIG. 1, 1 is a simultaneous ignition type ignition coil, which has a primary coil W1 and a secondary coil W2, and one end and the other end of the secondary coil W2 are respectively attached to the first cylinder and the second cylinder of the engine. The spark plugs 2A and 2B are connected to ungrounded terminals.
[0030]
Reference numeral 3 denotes a flywheel magnet generator attached to the internal combustion engine. On the stator side, an exciter coil Le for supplying ignition energy to the ignition device and another generator coil La are provided.
[0031]
4 is a signal generator that generates a pulse signal at a predetermined crank angle position of the internal combustion engine. This signal generator is 180 degrees on the outer periphery of the flywheel of the flywheel magnet generator 3 corresponding to the two cylinders of the engine. A pair consisting of a first pulse Vs1 and a second pulse Vs2 having different polarities by detecting the front end side edge and the rear end side edge in the rotation direction of each of the two reluctors composed of protrusions (or recesses) formed at intervals. The pulse signal is generated twice during one rotation of the crankshaft. Of each pair of pulse signals, the first pulse Vs1 whose phase has advanced is relative to the top dead center position (crank angle position when the piston reaches top dead center) of each cylinder corresponding to the engine. The second pulse Vs2 is generated at the ignition position at low speed of each cylinder of the engine set near the top dead center position of the engine, which is generated at the reference position set at the sufficiently advanced crank angle position.
[0032]
Reference numeral 5 denotes an ignition control unit constructed by attaching components to a common circuit board, 6 denotes a mode selection switch operated by a driver, 7 denotes an exhaust temperature sensor composed of a temperature sensitive resistance element (thermistor), and an exhaust temperature sensor. 7 is attached to the exhaust pipe of the internal combustion engine.
[0033]
The ignition control unit 5 includes an ignition capacitor Ci having one end connected to one end of the primary coil W1 of the ignition coil 1, a thyristor Thi having an anode connected to the other end of the ignition capacitor Ci, and an ignition capacitor Ci. A capacitor charging diode Di having a cathode connected to the other end is provided, and an anode of the diode Di is connected to one end of the exciter coil Le. The cathode of the thyristor Thi, the other end of the exciter coil Le, and the other end of the primary coil of the ignition coil are connected to a ground circuit in the unit.
[0034]
In this example, the exciter coil Le, the ignition capacitor Ci, the thyristor Thi, the diode Di, and the ignition coil 1 form a known capacitor discharge type ignition circuit CDI.
[0035]
The ignition control unit 5 also includes a microprocessor 5A, waveform shaping circuits 5B and 5C, a power supply circuit 5D, an ignition signal output circuit 5E, a resistor R1 for applying a voltage to the exhaust gas temperature sensor 7, and a signal generator 4 Diodes D1 and D2 for inputting outputs to the waveform shaping circuits 5B and 5C, and a resistor R2 for applying a power supply voltage to the ignition signal output circuit 5E are provided.
[0036]
The power supply circuit 5D is a circuit that generates a power supply voltage (5V) to be applied to the microprocessor 5A and the like. The power supply circuit is rectified to rectify the output of the power generation coil La and is controlled so as to keep the output of the rectifier circuit constant. And the regulator to be configured.
[0037]
The waveform shaping circuits 5A and 5B are circuits for converting the output pulse of the signal generator 4 into a signal having a waveform that can be recognized by the microprocessor 5A. The waveform shaping circuits 5A and 5B each have a first pulse generated by the signal generator 4. Vs1 and the second pulse Vs2 are input through the diodes D1 and D2, and the outputs of the waveform shaping circuits 5A and 5B are input to predetermined ports of the microprocessor 5A.
[0038]
The ignition signal output circuit 5E is a circuit that applies an ignition signal Vi to the gate of the thyristor Thi when the microprocessor 5A generates an ignition command. A power supply voltage is applied to the ignition signal output circuit through a resistor R2 from the power supply circuit 5D. Has been.
[0039]
The mode selection switch 6 is a switch that constitutes mode selection means, and is turned on when the exhaust temperature control mode is selected, and is turned off when the control mode during steady operation is selected. A signal obtained by turning on / off the mode selection switch 6 is input to a predetermined port of the microprocessor 5A.
[0040]
When the driver desires good starting acceleration after starting the engine, the mode selection switch 6 is turned on, and sufficient time has passed for the engine exhaust temperature to reach the target exhaust temperature. Later, the mode selection switch 6 is turned off to start the vehicle.
[0041]
The exhaust temperature sensor 7 is connected to the output terminal of the power supply circuit 5D through the resistor R1, and exhaust temperature detection signals obtained at both ends of the exhaust temperature sensor 7 are input to the analog input terminal of the microprocessor 5A.
[0042]
In the ignition device shown in FIG. 1, when the crankshaft of the internal combustion engine rotates, an AC voltage is induced in the exciter coil Le and the power generation coil La in the magnet generator 3. The ignition capacitor Ci is charged with the polarity shown in the figure through the diode Di and the primary coil W1 of the ignition coil with a positive half-wave voltage generated by the exciter coil Le.
[0043]
When the ignition signal Vi is supplied from the microprocessor 5A to the thyristor Thi through the ignition signal output circuit 5E, the thyristor Thi is turned on, so that the charge accumulated in the ignition capacitor Ci is the primary of the thyristor Thi and the ignition coil 1. A high voltage for ignition is induced in the secondary coil W2 of the ignition coil by discharging through the coil. Since this high voltage is applied to the spark plugs 2A and 2B, spark discharge occurs in these spark plugs, and an ignition operation is performed in the cylinder at the ignition timing of the two cylinders of the engine.
[0044]
The microprocessor 5A constitutes various control means necessary for controlling the timing (ignition timing) for giving an ignition signal to the thyristor Thi by executing a predetermined program.
[0045]
FIG. 2 shows the configuration of a vehicle equipped with a control device according to the present invention, together with control means realized by a microprocessor 5A. In the figure, reference numeral 10 denotes a two-cycle two-cylinder internal combustion engine. The rotation of the crankshaft of this internal combustion engine is connected to an automatic clutch such as a centrifugal clutch (when the rotational speed of the engine reaches a predetermined power transmission start rotational speed, Is transmitted to the drive wheel 12 via a transmission 11 having a clutch). Reference numeral 10a denotes an exhaust pipe of the internal combustion engine, and an exhaust temperature sensor 7 composed of a temperature sensitive resistance element is attached to the exhaust pipe 10a.
[0046]
The microprocessor 5A, by executing a program stored in the ROM, exhaust temperature sampling means 13 for sampling the exhaust temperature detected by the exhaust temperature sensor 7 at a constant time interval (for example, 0.1 sec interval); A determination value calculating means 14 for calculating a determination value X from the sampled exhaust temperature, an ignition control means 15 having a steady-time point fire control means 15A and an exhaust temperature rise ignition control means 15B, and an overspeed control means 16 are configured. To do.
[0047]
The judgment value calculating means 14 is a difference ΔTxn (= Txn−Ts) between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means 13 and the target exhaust temperature Ts set to a value suitable for traveling of the vehicle. From the difference ΔTxn−1 (= Txn−1−Ts) between the exhaust temperature Txn−1 sampled before a certain time and the target exhaust temperature Ts, and the constants α1 and α2 (α2> α1), the determination value X = α1 · The value of ΔTxn + α2 · (ΔTxn−ΔTxn−1) is calculated.
[0048]
As described above, the determination value X is a numerical value indicating how much the exhaust temperature has approached the target exhaust temperature when the exhaust temperature is changed toward the target exhaust temperature, and the exhaust temperature is higher than the target exhaust temperature. In the process of approaching the target exhaust temperature from a low state, the absolute value decreases as the difference between the exhaust temperature and the target exhaust temperature decreases, and before the exhaust temperature reaches the target exhaust temperature, the absolute value decreases from a negative value to a positive value. The sign is inverted to the value. The values of the constants α1 and α2 are experimentally determined by looking at the exhaust temperature control result, but it has been confirmed in the experiment that good results can be obtained when α1 = 1 and α2 = 5.
[0049]
The constant ignition control means 15A includes engine speed information obtained from the pulse generation interval generated by the signal generator 4 when the mode selection switch 6 selects the steady operation control mode, and exhaust temperature sampling. Ignition timing calculation means for calculating the ignition timing of the internal combustion engine with respect to the exhaust temperature of the engine sampled by the means 13, and ignition timing detection means for detecting the calculated ignition timing.
[0050]
The ignition timing calculation means is means for calculating the ignition timing with respect to the engine speed and the exhaust temperature. For example, the basic ignition timing calculation means for calculating the basic ignition timing calculated with respect to the rotation speed, and the basic ignition The ignition timing correcting means corrects the basic ignition timing calculated by the timing calculating means so that the basic ignition timing is corrected to the later side as the exhaust gas temperature is lower.
[0051]
When the signal generator 4 generates the first pulse Vs1 at the reference position, the ignition timing detection means sets the time required for the engine to rotate from the reference position to the crank angle position corresponding to the ignition timing in a timer. When the timer completes the measurement operation (when the ignition timing is detected), an ignition command is given to the ignition signal output circuit 5E, and the ignition signal Vi is output from the ignition signal output circuit. Is output.
[0052]
The exhaust temperature rise ignition control means 15B is in a state where the exhaust gas temperature control mode is selected by the mode selection switch 6 (in this example, when the switch 6 is in the ON state), and the determination value X is negative. The maximum retard angle control ignition control is performed as a first ignition timing that is further delayed by a set angle than the minimum advance angle ignition timing during steady operation that is the most delayed ignition timing during steady operation. The ignition timing of the internal combustion engine is determined according to the sign of the determination value X so that the minimum retarded ignition control is performed as the second ignition timing that is advanced from the first ignition timing when the value of the engine is positive. To control.
[0053]
The target exhaust temperature suitable for traveling of the vehicle is, for example, 500 ° C., and in this case, the first ignition timing is, for example, a timing corresponding to a crank angle position delayed by 30 ° from the top dead center position of the engine. . Also, the second ignition timing is appropriate, for example, a timing corresponding to a crank angle position that is delayed by 5 ° from the top dead center position of the engine.
[0054]
When the determination value X is a negative value, the ignition timing is the first ignition timing, and when the determination value X is a positive value, the ignition timing is advanced from the first ignition timing. When the exhaust gas temperature is low, the exhaust gas temperature can be rapidly raised toward the target exhaust gas temperature by a large retardation of the ignition timing when the exhaust gas temperature is low. When the exhaust temperature approaches the target exhaust temperature, the sign of the determination value X is reversed from negative to positive without waiting for the exhaust temperature to reach the target exhaust temperature. Therefore, before the exhaust temperature greatly exceeds the target exhaust temperature. The exhaust gas temperature can be lowered by reducing the retard amount of the ignition timing.
[0055]
In this way, if the retard amount of the ignition timing is controlled in accordance with the sign of the determination value X, a change in the exhaust temperature can be predicted and controlled, so that the temperature fluctuation range near the target exhaust temperature can be reduced. It is possible to perform control to keep the exhaust temperature at the target exhaust temperature while suppressing to a small range.
[0056]
In the above configuration, the judgment value X is calculated using the arithmetic formula X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1), and when the judgment value X is negative, the ignition timing is delayed most during steady operation. The first ignition timing that is further delayed by the set angle than the minimum advance ignition timing during steady operation, which is the ignition timing, is advanced from the first ignition timing when the determination value X is positive. Although the second ignition timing is set, the determination value X is calculated by the arithmetic expression X = −α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn), and the ignition timing is steady when the determination value X is positive. The first ignition timing that is further delayed by the set angle than the minimum advance ignition timing during steady operation, which is the most delayed ignition timing during operation, and the ignition timing when the determination value X is negative Grayed may also be set as the second ignition timing advanced from the first ignition timing.
[0057]
In this case, the judgment value calculation means 14 is the difference ΔTxn (= Txn−Ts) between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means 13 and the target exhaust temperature Ts set to a value suitable for vehicle travel. The determination value X = − from the difference ΔTxn−1 (= Txn−1−Ts) between the exhaust temperature Txn−1 sampled a predetermined time ago and the target exhaust temperature Ts and the constants α1 and α2 (α2> α1). It is configured to calculate the value of α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn).
[0058]
Further, the exhaust temperature rise ignition control means 15B has a minimum progress time in steady operation that is the most delayed ignition timing in steady operation when the judgment value X is positive in the state where the exhaust temperature control mode is selected. A first ignition timing that is further delayed by a set angle than the angular ignition timing is set to be a second ignition timing that is advanced from the first ignition timing when the determination value X is negative. The ignition timing is controlled according to the determination value.
[0059]
The determination value X = −α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn) has a small difference between the exhaust temperature and the target exhaust temperature in the process of approaching the target exhaust temperature from a state where the exhaust temperature is lower than the target exhaust temperature. As the value becomes smaller, the sign reverses from positive to negative before the exhaust temperature reaches the target exhaust temperature.
[0060]
Therefore, when the determination value X is a positive value, the ignition timing is set as the first ignition timing, and when the determination value X becomes a negative value, the second ignition timing is advanced from the first ignition timing. By performing control to switch to the ignition timing, it is possible to perform control to keep the exhaust temperature at the target exhaust temperature while suppressing the temperature fluctuation range near the target exhaust temperature to a small range as described above.
[0061]
The overspeed control means 16 sets the rotational speed of the internal combustion engine in the vicinity of the power transmission start rotational speed of the automatic clutch provided in the transmission 11 in a state where the exhaust gas temperature control mode is selected by the mode selection switch 6. When the set speed (for example, 4000 r / min) is reached, the internal combustion engine is misfired or the ignition timing is delayed, thereby controlling the engine speed to be lower than the set speed.
[0062]
In order to cause the engine to misfire when the rotation speed of the internal combustion engine reaches the set speed, for example, it is only necessary to prohibit the ignition signal from being supplied to the ignition circuit from the ignition temperature raising ignition control means 15B.
[0063]
The set speed is set to a rotational speed equal to or lower than the power transmission start rotational speed of the automatic clutch, preferably a rotational speed slightly lower than the power transmission start rotational speed.
[0064]
FIG. 3 is a flowchart showing an example of an algorithm of a program executed by the microprocessor when the key switch is in the ON state in order to realize each control unit shown in FIG. In the case of the algorithm shown in FIG. 3, it is determined in step 1 whether or not the mode selection switch 6 is in an on state. If the mode selection switch 6 is in an on state, the process proceeds to step 2 and ignition in steady operation is performed. Let control take place. This step 2 constitutes the steady point fire control means 15A.
[0065]
If it is determined in step 1 that the mode selection switch is in the ON state, the process proceeds to step 3 where the exhaust temperature detected by the exhaust temperature sensor is sampled at regular sampling times (for example, at intervals of 0.1 sec). Then, a difference ΔTxn between the newly sampled exhaust temperature Txn and the target exhaust temperature Ts set to a value suitable for traveling of the vehicle is calculated. Next, in step 4, the determination value X is obtained by calculating X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1), where ΔTxn calculated at the time of sampling a predetermined time before is ΔTxn−1. The exhaust temperature sampling means is constituted by the process of sampling the exhaust temperature in step 3, and the judgment value calculating means 14 is constituted by the process of calculating ΔTxn in step 3 and step 4.
[0066]
After calculating the determination value X in step 4, it is determined in step 5 whether or not the determination value X is positive. As a result of this determination, when it is determined that the determination value X is negative, the routine proceeds to step 6 where the ignition timing is set further than the minimum advance ignition timing during steady operation, which is the most delayed ignition timing during steady operation. Maximum retard ignition control is performed with the first ignition timing delayed by an angle.
[0067]
If it is determined in step 5 that the determination value X is positive (including X = 0), the process proceeds to step 7 where the second ignition in which the ignition timing is advanced from the first ignition timing. The minimum retarded ignition control as the timing is performed. In this example, the exhaust temperature raising ignition control means 15B is constituted by steps 5 to 7.
[0068]
After executing Step 6 or Step 7, Step 8 is executed to determine whether or not the engine speed N is equal to or higher than the set speed Ns. When it is determined that the engine speed is not equal to or higher than the set speed, Step 1 is executed. Return. If it is determined in step 8 that the rotational speed N is greater than or equal to the set speed, step 9 is executed to cause the engine to misfire and reduce the rotational speed of the engine.
[0069]
When the above-described control is performed, the mode selection switch is turned on after the engine is started, thereby preventing the vehicle from starting and raising the engine exhaust temperature to the target exhaust temperature. In this state, a sufficient output can be obtained, and a good acceleration performance can be obtained by starting the vehicle with the mode selection switch turned off.
[0070]
After starting the engine, the time required to raise the exhaust temperature to the target exhaust temperature is, for example, about 20 seconds.
[0071]
In the above embodiment, the over-rotation control means is provided. However, when the exhaust temperature rise control is performed, there is no possibility that the engine rotation speed is not equal to or higher than the power transmission start rotation speed of the automatic clutch. When the clutch to be used is used, the overspeed control means can be omitted.
[0072]
In the above embodiment, the mode selection switch 6 operated by the driver is used as the mode selection means. However, when the engine is started, the ignition temperature raising ignition control mode is selected, and the driving operation for starting the vehicle is performed. The mode selection means may be configured to automatically switch the control mode to the steady operation time point fire control mode.
[0073]
【The invention's effect】
As described above, according to the present invention, the mode selection means for selecting the exhaust temperature control mode and the steady operation control mode, and the exhaust temperature is controlled when the exhaust temperature control mode is selected by the mode selection means. Since the exhaust temperature increase ignition control means for controlling the ignition timing of the internal combustion engine so as to raise the target exhaust temperature set to a value suitable for traveling and keep the exhaust temperature close to the target exhaust temperature is provided. Before starting the vehicle, by selecting the exhaust temperature control mode by the mode selection means, the ignition timing of the engine can be retarded and the exhaust temperature can be raised to the target exhaust temperature suitable for steady operation. The acceleration performance of the engine when starting can be improved.
[0074]
In particular, in the present invention, provided is a determination value calculation means for calculating a determination value X whose sign is inverted when the exhaust temperature approaches the target exhaust temperature in the process in which the exhaust temperature rises toward the target exhaust temperature. In accordance with the sign of this determination value, the ignition timing is delayed by a set angle further than the minimum advance ignition timing during steady operation, and the second ignition timing is advanced from the first ignition timing. By controlling to switch to the ignition timing, the exhaust temperature is kept near the target exhaust temperature, so that the exhaust temperature is controlled to the target exhaust temperature while suppressing the fluctuation range of the exhaust temperature near the target exhaust temperature to a small range. There is an advantage that control can be performed to keep the
[0075]
Further, in the present invention, when the exhaust temperature control mode is selected by the mode selection means, the internal combustion engine is misfired when the rotational speed of the internal combustion engine reaches a set speed set near the power transmission start rotational speed of the automatic clutch. Thus, when an overspeed control means for limiting the rotational speed of the internal combustion engine to a set speed or less is provided, control in the exhaust temperature control mode is performed in a vehicle in which a transmission having an automatic clutch is used. In this case, it is possible to prevent the vehicle from starting when the rotational speed of the engine exceeds the power transmission start rotational speed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically illustrating a hardware configuration according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a vehicle equipped with a control device according to the present invention, together with control means realized by a microprocessor 5A.
FIG. 3 is a flowchart showing an example of a program algorithm executed by a microprocessor to realize the control means shown in FIG. 2;
[Explanation of symbols]
1 Ignition coil
2A, 2B Spark plug
3 Flywheel magnet generator
4 Signal generator
5 Ignition control unit
5A microprocessor
6 Mode selection switch
7 Exhaust temperature sensor
CDI capacitor discharge ignition circuit

Claims (6)

An exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives a vehicle, and an ignition control means for controlling an ignition timing of the internal combustion engine with respect to various control conditions, the ignition control means including the exhaust temperature sensor In the control device for a vehicle-driving internal combustion engine configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust temperature detected by the
Mode selection means for selecting an exhaust temperature control mode and a steady operation control mode;
Exhaust temperature sampling means for sampling the exhaust gas temperature detected by the exhaust gas temperature sensor at regular time intervals;
The difference ΔTxn between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means and the target exhaust temperature Ts set to a value suitable for vehicle travel, the exhaust temperature Txn−1 sampled a predetermined time ago, and the target Judgment value computing means for computing a value of judgment value X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1) from a difference ΔTxn−1 with respect to the exhaust temperature Ts and constants α1 and α2 (α2>α1);
When the exhaust gas temperature control mode is selected and the determination value X is negative, the ignition timing is set at a further set angle than the minimum advance ignition timing during steady operation, which is the most delayed ignition timing during steady operation. According to the determination value so that the first ignition timing is delayed by a certain amount, and when the value of the determination value X is positive, the ignition timing is a second ignition timing advanced from the first ignition timing. And an exhaust temperature rise ignition control means for controlling the ignition timing of the internal combustion engine,
An ignition control device for an internal combustion engine for driving a vehicle. An exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives a vehicle, and an ignition control means for controlling an ignition timing of the internal combustion engine with respect to various control conditions, the ignition control means including the exhaust temperature sensor In the control device for a vehicle-driving internal combustion engine configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust temperature detected by the
Mode selection means for selecting an exhaust temperature control mode and a steady operation control mode;
Exhaust temperature sampling means for sampling the exhaust gas temperature detected by the exhaust gas temperature sensor at regular time intervals;
The difference ΔTxn between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means and the target exhaust temperature Ts set to a value suitable for vehicle travel, the exhaust temperature Txn−1 sampled a predetermined time ago, and the target Judgment value computing means for computing a value of judgment value X = −α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn) from the difference ΔTxn−1 with the exhaust temperature Ts and constants α1 and α2 (α2>α1);
When the exhaust gas temperature control mode is selected and the determination value X is positive, the ignition timing is set at a further set angle than the minimum advanced ignition timing during steady operation, which is the most delayed ignition timing during steady operation. According to the determination value so that the first ignition timing is delayed by a certain amount, and when the determination value X is negative, the ignition timing is a second ignition timing that is advanced from the first ignition timing. And an exhaust temperature rise ignition control means for controlling the ignition timing of the internal combustion engine,
An ignition control device for an internal combustion engine for driving a vehicle. An exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives a vehicle via an automatic clutch; and an ignition control means for controlling an ignition timing of the internal combustion engine with respect to various control conditions, the ignition control means comprising: In the control device for an internal combustion engine for driving a vehicle configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust temperature detected by the exhaust temperature sensor is low,
Mode selection means for selecting an exhaust temperature control mode and a steady operation control mode;
When the exhaust temperature control mode is selected by the mode selection means, the exhaust temperature is raised to a target exhaust temperature set to a value suitable for traveling of the vehicle so as to keep the exhaust temperature close to the target exhaust temperature. And an ignition temperature rise ignition control means for controlling the ignition timing of the internal combustion engine,
The internal combustion engine is misfired when the rotational speed of the internal combustion engine reaches a set speed set near the power transmission start rotational speed of the automatic clutch in a state where the exhaust gas temperature control mode is selected by the mode selection means. Or overspeed control means for limiting the rotational speed of the internal combustion engine to the set speed or less by delaying the ignition timing of the internal combustion engine,
An ignition control device for an internal combustion engine for driving a vehicle. An exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives a vehicle via an automatic clutch; and an ignition control means for controlling an ignition timing of the internal combustion engine with respect to various control conditions, the ignition control means comprising: In the control device for an internal combustion engine for driving a vehicle configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust temperature detected by the exhaust temperature sensor is low,
Mode selection means for selecting an exhaust temperature control mode and a steady operation control mode;
Exhaust temperature sampling means for sampling the exhaust gas temperature detected by the exhaust gas temperature sensor at regular time intervals;
The difference ΔTxn between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means and the target exhaust temperature Ts set to a value suitable for vehicle travel, the exhaust temperature Txn−1 sampled a predetermined time ago, and the target Judgment value computing means for computing a value of judgment value X = α1 · ΔTxn + α2 · (ΔTxn−ΔTxn−1) from a difference ΔTxn−1 with respect to the exhaust temperature Ts and constants α1 and α2 (α2>α1);
When the exhaust gas temperature control mode is selected and the determination value X is negative, the ignition timing is set further than the steady operation minimum advance ignition timing which is the most delayed ignition timing during steady operation. A first ignition timing delayed by an angle is used, and when the value of the determination value X is positive, the ignition timing is set to a second ignition timing that is advanced from the first ignition timing. And an ignition temperature raising ignition control means for controlling the ignition timing of the internal combustion engine in response,
The internal combustion engine is misfired when the rotational speed of the internal combustion engine reaches a set speed set near the power transmission start rotational speed of the automatic clutch in a state where the exhaust gas temperature control mode is selected by the mode selection means. Or overspeed control means for limiting the rotational speed of the internal combustion engine to the set speed or less by delaying the ignition timing of the internal combustion engine,
An ignition control device for an internal combustion engine for driving a vehicle. An exhaust temperature sensor for detecting an exhaust temperature of an internal combustion engine that drives a vehicle, and an ignition control means for controlling an ignition timing of the internal combustion engine with respect to various control conditions, the ignition control means including the exhaust temperature sensor In the control device for a vehicle-driving internal combustion engine configured to correct the ignition timing of the internal combustion engine to the delay side when the exhaust temperature detected by the
Mode selection means for selecting an exhaust temperature control mode and a steady operation control mode;
Exhaust temperature sampling means for sampling the exhaust gas temperature detected by the exhaust gas temperature sensor at regular time intervals;
The difference ΔTxn between the exhaust temperature Txn newly sampled by the exhaust temperature sampling means and the target exhaust temperature Ts set to a value suitable for vehicle travel, the exhaust temperature Txn−1 sampled a predetermined time ago, and the target Judgment value computing means for computing a value of judgment value X = −α1 · ΔTxn + α2 · (ΔTxn−1−ΔTxn) from the difference ΔTxn−1 with the exhaust temperature Ts and constants α1 and α2 (α2>α1);
When the exhaust gas temperature control mode is selected and the determination value X is positive, the ignition timing is set at a further set angle than the minimum advanced ignition timing during steady operation, which is the most delayed ignition timing during steady operation. According to the determination value so that the first ignition timing is delayed by a certain amount, and when the determination value X is negative, the ignition timing is a second ignition timing that is advanced from the first ignition timing. And an exhaust temperature rise ignition control means for controlling the ignition timing of the internal combustion engine,
The internal combustion engine is misfired when the rotational speed of the internal combustion engine reaches a set speed set near the power transmission start rotational speed of the automatic clutch in a state where the exhaust gas temperature control mode is selected by the mode selection means. Or overspeed control means for limiting the rotational speed of the internal combustion engine to the set speed or less by delaying the ignition timing of the internal combustion engine,
An ignition control device for an internal combustion engine for driving a vehicle. The exhaust temperature raising ignition control means is configured to reduce the ignition timing at a minimum in steady operation, which is the most delayed ignition timing in steady operation when the exhaust temperature detected by the exhaust temperature sensor is lower than the target exhaust temperature. The second ignition timing is set to a first ignition timing that is further delayed by a set angle than the angular ignition timing, and the ignition timing is advanced from the first ignition timing when the exhaust gas temperature exceeds the target exhaust gas temperature. The ignition control device for an internal combustion engine for driving a vehicle according to any one of claims 1 to 5, wherein the ignition timing is switched in accordance with an exhaust gas temperature detected to be a timing.

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