JPH0713463B2 - In-vehicle internal combustion engine control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control method for a vehicle-mounted internal combustion engine, and more particularly to a control method for a vehicle-mounted internal combustion engine capable of controlling intake or exhaust timing.

BACKGROUND ART In order to improve the output performance of an internal combustion engine such as a two-cycle engine, a four-cycle engine, and a rotary engine,
A method of controlling intake or exhaust timing of an internal combustion engine is known. For example, in Japanese Patent Laid-Open No. 61-4820, the position of the upper edge of the exhaust port of a two-cycle engine is configured to be variable, and the upper edge position of the exhaust port is controlled according to engine parameters such as engine speed and its output. A two-cycle engine is shown with a control device to improve the engine.

SUMMARY OF THE INVENTION The present invention controls the intake or exhaust timing of a vehicle-mounted internal combustion engine equipped with a control device for controlling the intake or exhaust timing to reduce the engine output, thereby reducing the engine output under a predetermined condition. An object of the present invention is to provide a control method for an on-vehicle internal combustion engine that can perform suitable control of traveling.

In the method for controlling an on-vehicle internal combustion engine according to the present invention, a predetermined state in which the output of the on-vehicle internal combustion engine is to be reduced is detected, and when it is not the predetermined state, the intake or exhaust timing of the on-vehicle internal combustion engine is set as an operating parameter of the on-vehicle internal combustion engine. It is characterized in that the maximum output generation timing at which the maximum output is obtained is set based on the above, and in the predetermined state, the intake or exhaust timing is deviated from the maximum output generation timing.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment apparatus in which the control method for an internal combustion engine according to the present invention is applied to a two-cycle engine mounted on a motorcycle.

The two-cycle engine 1 has an exhaust port 4 that opens in a cylinder 2 and is opened and closed by a piston 3. An exhaust pipe 6 in which an expansion chamber 5 is formed is connected to the exhaust port 4 to form an exhaust passage. The expansion chamber 5 is formed in a shape in which the central portion thereof swells in the exhaust gas flow direction and both end portions thereof are narrowed, so that the so-called exhaust reflected wave action (Kadenashi effect) can be utilized.

At the upper edge of the exhaust port 4, a flap shutter 8 is connected to a rotating shaft 9 and is pivotally provided. The rotating shaft 9 is an output shaft of the speed reducer 12 that reduces the rotational output of the pulse motor 10, and the flap shutter 8 is pivoted according to the rotational output of the pulse motor 10 to be positioned at a desired angular position. The free end of the flap shutter 8 is located at the upper edge of the exhaust port 4 and forms the upper edge of the exhaust port 4. Therefore, the pivotal movement of the flap shutter 8 causes the upper edge position of the exhaust port 4 to move up and down, and the exhaust timing can be changed. That is, the flap shutter 8, the speed reducer 12 and the pulse motor 10 constitute an exhaust timing adjusting mechanism. The pulse motor 10
Is provided with an encoder 13 for detecting the operating state of the pulse motor 10. The output signal of the encoder 13 is input to the address detection circuit 14 and drives the flap shutter 8.
An address signal indicating the operating position of is input from the address detection circuit 14 to the control circuit 16.

On the other hand, the synchronization pulse generating means 23 generates a rotation angle position signal (hereinafter referred to as B pulse) synchronized with the rotation of the crankshaft 24 of the engine. Specifically, a rotor that rotates in synchronism with the rotation of the crankshaft 24, which has a large number of claws 23a, is combined with a magnetic pickup 23b, and is applied as an output signal of the magnetic pickup 23b.
Means for obtaining pulses are known.

Further, the reference position pulse generating means 25 is the crankshaft 24
Generates a reference rotation angle position signal (hereinafter, referred to as A pulse) indicating that a predetermined rotation angle position before TDC (piston top dead center), that is, a reference rotation angle position is reached. This A pulse can be obtained by separately providing a claw 25a for A pulse on the rotor used for the synchronous pulse generating circuit 23 and providing a magnetic pickup 25b for A pulse generation.

The fixed cycle clock 27 generates a clock pulse of a predetermined cycle by dividing a clock signal from a high frequency clock source (not shown), and the clock pulse is a clock counter.
Input to 28. The clock counter 28 counts the fixed period clock pulse after being cleared by the B pulse. That is, the count value of the clock counter 28 indicates the elapsed time after the B pulse is generated.

The control circuit 16 is composed of, for example, a microcomputer including a CPU, a ROM, and a RAM, and performs arithmetic operation according to a main routine or an interrupt subroutine described later. Also,
A throttle signal corresponding to the rotational position of the throttle grip 32 for detecting the rotational position of the throttle grip 31 is input to the control circuit 16 as a parameter indicating the throttle valve opening of the engine 1, and a water temperature sensor 33, A vehicle temperature sensor 34, an exhaust gas temperature sensor 35, a residual fuel sensor 36, a front wheel rotation sensor 37, and a rear wheel rotation sensor 38 respectively indicate a water temperature signal corresponding to the temperature of the cooling water of the engine 1, and indicate that the vehicle speed exceeds a predetermined vehicle speed. Vehicle speed signal, exhaust temperature signal according to exhaust gas temperature, low fuel level signal indicating that the amount of fuel remaining in the fuel tank (not shown), front wheel (not shown)
The front wheel rotation signal corresponding to the rotation speed of the rear wheel and the rear wheel rotation signal corresponding to the rotation speed of the rear wheel (not shown) are input. As the water temperature sensor 33, one formed of a temperature sensitive element such as a thermistor is known, and is fixed to, for example, a cylinder block of the engine 1. As the vehicle speed sensor 34, a photocoupler provided in a speedometer (not shown) is well known. Like the water temperature sensor 33, the exhaust temperature sensor 35 is formed of a temperature sensitive element such as a thermistor and is fixed to the exhaust pipe 6. As the fuel sensor 36, a float switch type or a thermistor switch type is known. The front wheel rotation sensor 37 and the rear wheel rotation sensor 38 are configured, for example, by providing a reed switch which is provided with magnets on each axle and which is opened and closed by rotation of the magnets in the vicinity thereof. The low fuel level signal output from the residual fuel sensor 36 can be canceled by, for example, a handle switch (not shown) provided near the throttle grip.

The control circuit 16 controls the flap shutter 8 corresponding to the desired ignition angle θ _IG on the crank angle and the target exhaust magnetism at which the exhaust port 4 should start to open based on the engine speed Ne and the throttle signal calculated based on the above-mentioned B pulse. The target rotation angle position (hereinafter referred to as the target exhaust angle) θ _T is calculated, and based on the calculation result, for example, the CDI ignition system 40 is triggered to cause the spark plug 41 to be spark-discharged and the pulse motor 10 is driven. Then, the exhaust timing is adjusted.

2 to 5 show the setting operation of the ignition angle θ _IG and the target exhaust angle θ _T of the control circuit 16 and the ignition command when the crank angle reaches the ignition angle θ _IG , and the flap shutter 8 rotates. 7 is a flowchart showing a main routine and a subroutine that control a command operation for matching the angular position (exhaust angle) θ _V with the target exhaust angle θ _T.

As shown in FIG. 2, when the power is turned on, the control circuit
In 16, the main routine is sequentially executed for each step according to the fixed-cycle clock pulse. First, in the first step S ₁ , the initialization operation is executed. Next, a comparison is made between the current exhaust angle θ _V calculated by the address signal output from the address detection circuit 14 and the target exhaust angle θ _T obtained by executing a subroutine described later (steps S ₂ and S ₃ ). , If the difference between the current exhaust angle θ _V and the target exhaust angle θ _T is larger than a predetermined value ε _{O, the} drive circuit 42 is driven by that amount to drive the pulse motor 10 (step
S ₄ , S ₅ ).

FIG. 3 (A) shows a flowchart of a fixed-cycle interrupt subroutine that is executed by interrupting the main routine at regular intervals. In this subroutine, when the main routine is interrupted, first, the throttle opening θ _TH , the engine speed Ne, the exhaust temperature T _EX , the water temperature T _W , the vehicle speed V, and the front wheel speed N _F
And the rear wheel rotation speed N _R are fetched (step S ₆ ). Next, whether or not the exhaust temperature T _EX exceeds the upper limit exhaust temperature T _EXmax and is abnormally increased (step S ₇ ), the water temperature T _W is compared with the water temperature T _WC when the engine 1 has finished warming up. whether warming up is completed (step S _8), whether or not the engine 1 as compared to the temperature T _WH upper acceptable water temperature T _W is not heated abnormally (step S _9), the vehicle speed V Does not exceed the maximum permissible vehicle speed V _max (step S ₁₀ ), compares the rotation speeds N _F and N _R of the front wheels and the rear wheels, and determines whether the rear wheels are idling (step S ₁ ). and whether the fuel quantity low signal is input performs discrimination (step S _12), if the exhaust gas temperature T _EX is abnormally high exceeding the upper limit exhaust temperature T _EXmax, water temperature water temperature T _W is at warm-up completion If T _WC is lower and engine 1 has not been warmed up, the water temperature T _W will rise abnormally
When T _TH is exceeded, that is, when the temperature of the engine 1 becomes abnormally high, when the vehicle speed V exceeds the allowable maximum vehicle speed V _max , the rotation speed N _R of the rear wheels is equal to the rotation speed N _F of the front wheels. When the number of revolutions exceeds N _O or more, or when the low fuel level signal is input, it is determined that the output of the engine 1 should be reduced, and a flag F indicating that is set to 1 (step S ₁₃ ). Otherwise, that is, if not in the condition to allowed to lower the output of the engine 1 and resets the flag F (step S _14). Then, based on the map I stored in advance, the target exhaust angle θ _T corresponding to the maximum output generation timing at which the maximum output is exhibited at the engine speed Ne is searched according to the engine speed Ne and the throttle opening θ _TH ( step S _15). Next, the flag F is 1
To perform equal whether the determination (step S _16), if the switch flag F was equal to 1, that is, the engine 1
When the output of the engine 1 is to be reduced, the exhaust angle θ _TO that maximizes the output in the low rotation range of the engine 1 near the idle speed is newly set to the target exhaust angle θ _T (switch S ₁₇ ).

FIG. 3 (B) shows another fixed cycle interrupt subroutine compatible with the fixed cycle interrupt subroutine shown in FIG. 3 (A). In the figure, the same steps as those in FIG. 3 (A) are designated by the same reference numerals, and the description thereof will be omitted.

In the fixed-cycle interrupt subroutine shown in FIG. 3 (B), if it is determined in step S ₁₆ that the output of the engine 1 should be reduced, step S _16
The exhaust timing is deviated from the maximum output generation timing by adding or subtracting the predetermined angle θ _O to the target exhaust angle θ _T obtained in _{15 to} obtain a new target exhaust angle θ _T (step S ₁₈ ). Thus, determine the predetermined angle theta _O of addition or subtraction to new target exhaust angle theta _T to the target angle theta _T corresponding to a maximum output generation timing determined in step S _15, exhaust timing a maximum output generation This is because the engine output can be reduced regardless of whether the angle is advanced or retarded from the timing. Then, whether or not the target exhaust angle theta _T is a value within the range of rotation of the upper end position of the flap shutter 8 to the lower end position, i.e., the maximum exhaust angle target exhaust angle theta _T is theta
It is determined whether or not it is within the range from _vmax to the minimum exhaust angle θ _vmin , and if the target exhaust angle θ _T is not within that range, the maximum exhaust angle θ _vmax or the minimum exhaust angle θ _vmin is set as a new target. Set as exhaust angle θ _T (steps S ₁₉ , S ₂₀ , S ₂₁ , S
₂₂ ).

In this way, when the exhaust temperature T _EX becomes abnormally high, the exhaust timing is deviated from the maximum output timing and the output of the engine 1 is suppressed, so that the temperature rise in the cylinder 2 can be suppressed, and seizure or piston head can be suppressed. It is possible to prevent problems such as melting of the engine in advance, suppress the output of the engine 1 when warm-up is not completed, suppress the increase in the number of revolutions and prevent over-rotation during cold, and protect the engine 1. Even if T _W rises abnormally, engine overheat can be prevented by suppressing the engine output. Further, since the vehicle speed is limited by adjusting the exhaust timing when the vehicle speed V exceeds the maximum permissible vehicle speed V _max , the vehicle speed can be limited without a sudden decrease in output, and the rear wheels are idling. In this case, the grip (grounding force) of the rear wheels can be restored by lowering the engine output, and by suppressing the engine output when the fuel level becomes low, the fuel level in the driving vehicle must be low. Can be notified.

During the operation in the above-mentioned regular cycle interrupt subroutine, the engine speed Ne used for the calculation is obtained by executing the B pulse interrupt subroutine described later.

FIG. 4 shows a flowchart of the B pulse interrupt subroutine. This subroutine is executed in response to the B pulse by interrupting the above-mentioned main routine or the fixed-cycle interrupt subroutine. In this subroutine, B
An interrupt is generated by the generation of a pulse, and first, the count value Tam (m
= 0 to 7) and capture the count value CF of the internal free running counter of the control circuit 16 (m) (m = 0-7) (step S _23). Next, the difference ΔMe between the current CF (m) and the previous CF (m−1) is calculated (step S ₂₄ ). Then the latest 8
Individual data values ΔMe (m-7), ΔMe (m-6), ... Δ
Me (m−1) and ΔMe (m) are added and this is set as Me (m) (step S ₂₅ ). Then, the inverse of Me (m) and the engine speed Ne (step S _26), is incremented by 1 to count value FS of the stage counter (step
S ₂₇ ), the target ignition timing t for which the count value FS will be described later
Is input to a programmable count register (not shown) built in the control circuit 16 and waits until it becomes a value FS _IG suitable for starting down counting (step S ₂₈ ). was based on the map II, the reference ignition degree angle on the crank angle at which the maximum output is obtained at the engine speed Ne according to captured throttle opening theta _TH and the engine speed Ne at step S ₆ of the periodic interrupt subroutine Search for θ _1G (step S ₂₉ ). In addition,
The count value FS is as shown in the flowchart of FIG.
For example, -1 is set every time an A pulse is generated based on the A pulse interrupt subroutine. The A pulse interrupt subroutine is in response to an A pulse generated each time the crankshaft 24 makes one revolution, a main routine, a fixed cycle interrupt subroutine,
Alternatively, it is a subroutine for interrupting the B pulse interrupt subroutine.

After determining the reference ignition angle theta _IG in step S _29, the reference ignition angle theta _IG is divided by the engine speed Ne determined reference ignition timing T _IG (step S _30), whether or not the flag F is equal to 1 Is determined (step S ₃₁ ), and if the output of the engine 1 is to be decreased, the exhaust angle θ _TO or the predetermined angle θ _O used in step S ₁₇ or S ₁₈ of the fixed cycle interrupt subroutine is set. The corresponding predetermined ignition timing T _IGO is set to the target ignition timing t (step S ₃₂ ). Conversely, when it is not in a state where the output of the engine 1 should be decreased, the reference ignition timing T _IG is set to the target ignition timing t ( After step _S33 ), the target ignition timing t is output to the programmable count register as described above (step _S34 ). When the target ignition timing t is input, the register starts the down-counting and triggers the ignition system 40 when the count value reaches or falls below zero.

In this way, by controlling the ignition timing together with the exhaust timing, it is possible to synergistically reduce the engine output, and to promptly reduce the engine output when the output of the engine 1 should be reduced. I can.

FIG. 6 shows an enlarged sectional view in the vicinity of the exhaust port 4. As shown in the figure, if the sub-port 4a is formed at the upper edge of the exhaust port 4, the flap shutter 8 can shift the exhaust timing greatly from the maximum output generation timing while the movement amount of the flap shutter 8 is small. The rotation direction of the shutter 8 (advance side or retard side) occurs. Therefore, when the engine output should be reduced, if the flap shutter 8 is rotated in the rotation direction, the engine output can be reduced more quickly. This is particularly effective when reducing the engine output in order to prevent engine trouble.

Although the water temperature sensor 33 is used as a sensor for detecting the temperature of the engine 1 in the above-described embodiment, an oil temperature sensor (not shown) for detecting the temperature of the engine oil is used instead of the water temperature sensor 33. You can also

Although the above-described embodiment is applied to the two-cycle engine, the present invention is also applicable to the four-cycle engine and the rotary engine. The exhaust timing adjustment of the 4-cycle engine can be easily controlled by the control circuit 16 if the valve mechanism is an electromagnetic valve using an electromagnet.

As described above, in the control method for an on-vehicle internal combustion engine according to the present invention, a predetermined state in which the output of the on-vehicle internal combustion engine should be reduced is detected, and when it is not the predetermined state, intake air of the on-vehicle internal combustion engine or The exhaust timing is set to the maximum output generation timing at which the maximum output is obtained based on the operating parameters of the vehicle-mounted internal combustion engine, and when the predetermined state is set, the intake or exhaust timing is deviated from the maximum output generation timing. The engine output can be reduced under a predetermined condition where the engine output should be reduced while achieving the improvement of the output, and the vehicle running can be controlled appropriately.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment apparatus when the present invention is applied to a two-cycle engine mounted on a motorcycle, and FIG.
5 to 5 are flowcharts showing the operation of the apparatus of the embodiment shown in FIG. 1, and FIG. 6 is a partially enlarged sectional view in the vicinity of the exhaust port. Explanation of symbols of main parts 1 …… 2-cycle engine 4 …… Exhaust port 5 …… Expansion chamber 6 …… Exhaust pipe 8 …… Flap shutter 10 …… Pulse motor 13 …… Encoder 14 …… Address detection circuit 16 …… Control circuit 23 …… Synchronous pulse generator 24 …… Crankshaft 25 …… Reference position pulse generator 27 …… Clock cycle 28 …… Clock counter 31 …… Throttle grip 32 …… Throttle sensor 33 …… Water temperature sensor 34… … Vehicle speed sensor 35 …… Exhaust temperature sensor 36 …… Remaining fuel sensor 37 …… Front wheel rotation sensor 38 …… Rear wheel rotation sensor 40 …… Ignition system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Ouchi 1-4-1 Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (72) Inventor Hitoshi Nakayama 1-4-1 Chuo, Wako-shi, Saitama No. Stock Company Honda Technical Research Institute

Claims (6)

[Claims] 1. A control method for an on-vehicle internal combustion engine capable of controlling intake or exhaust timing, comprising: a step of detecting a state in which the output of the internal combustion engine is to be reduced; A vehicle-mounted internal combustion engine, characterized in that it comprises a stroke for setting a maximum output generation timing at which maximum output is obtained based on the operating parameters of the internal combustion engine, and a stroke for biasing the intake or exhaust timing from the maximum output generation timing in the above state. Engine control method. 2. The in-vehicle internal combustion engine according to claim 1, wherein the state in which the output of the internal combustion engine is to be reduced is a state in which the exhaust gas temperature of the internal combustion engine is equal to or higher than a predetermined temperature. Control method. 3. The control method for a vehicle-mounted internal combustion engine according to claim 1, wherein the state in which the output of the internal combustion engine is to be reduced is a state in which the internal combustion engine has not been warmed up yet. 4. The method for controlling an on-vehicle internal combustion engine according to claim 1, wherein the state in which the output of the internal combustion engine is to be reduced is a state in which the temperature of the internal combustion engine has reached a predetermined temperature or higher. . 5. The control method for an on-vehicle internal combustion engine according to claim 1, wherein the state in which the output of the internal combustion engine should be reduced is a state in which the remaining amount of fuel is below a predetermined amount. 6. The state in which the output of the internal combustion engine should be reduced is a state in which the number of revolutions of the rear wheels of the vehicle is greater than the number of revolutions of the front wheels of the vehicle by a predetermined number of revolutions or more. The control method for a vehicle-mounted internal combustion engine according to item 1.