JPS63248973A - Ignition timing controller for engine equipped with supercharger - Google Patents

Abstract

PURPOSE:To improve the turbo-efficiency by delay-angle-correcting the ignition timing and generating the after combustion state, when the upper limit of the supercharge pressure is not regulated by a supercharge pressure control means and the output is demanded in the operation zone where the increase of the supercharge pressure is permitted. CONSTITUTION:In an engine equipped with a supercharger, a supercharge control means 4 including a waste gate valve installed onto a supercharger 3 adjusts the supercharge pressure in the supercharge pressure regulating zone in which the exhaust gas quantity is high such as in the high revolution high loading state and exhaust gas temperature is high and the supercharge pressure exceeds an upper limit value, to a prescribed upper limit value. In this case, an operation zone judging means 7 for judging the zone having the supercharge pressure lower than the above-described upper limit supercharge pressure is installed. When the operation zone outside the supercharge pressure regulation zone is judged, and the output demand is judged, an ignition timing control means 6 allows a delay angle correcting means 8 to output a correction signal for delaying the ignition timing in comparison with the ignition timing in the supercharge pressure regulating zone.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ignition timing control device for a supercharged engine.

(Prior art) Conventionally, a turbo supercharger is installed in the intake passage of an engine to improve engine output by supplying supercharging air.
From the viewpoint of engine reliability, a supercharging engine is known that is equipped with a supercharging pressure control means for regulating the upper limit of supercharging pressure to a predetermined pressure (see, for example, Japanese Utility Model Application No. 124619/1983).

(Problem to be Solved by the Invention) However, when regulating the upper limit of boost pressure to a predetermined value as described above, there is a problem in areas where the boost pressure does not reach the upper limit, such as during acceleration in a low rotation range, etc. In this case, it is possible to improve the engine output by increasing the boost pressure.

In order to increase the boost pressure in such a region, it is best to improve the turbo efficiency of the turbo supercharger, and this turbo efficiency is proportional to the exhaust gas flow rate and is also proportional to the exhaust gas temperature. However, when accelerating at low speeds as mentioned above, there is less exhaust gas and the exhaust gas temperature is low, so the turbo efficiency is low, and the boost pressure decreases accordingly. This causes a decrease in engine torque.

Therefore, in view of the above circumstances, the present invention has been developed to control the turbo efficiency by controlling the ignition timing i! It is an object of the present invention to provide an ignition timing control device for a supercharged engine, which improves the engine output by improving the engine output.

(Means for Solving the Problems) The ignition timing control system of the present invention provides a supercharging system J3 in a predetermined operation zone and is equipped with a supercharging pressure control means that regulates the upper limit of supercharging pressure. An operating zone discriminating means for discriminating a zone where the supercharging pressure is lower than the upper limit supercharging pressure regulated by the pressure controlling means; The ignition timing control means is characterized in that the ignition timing control means includes retardation correction means for outputting a correction signal for retarding the ignition timing from the ignition timing in the boost pressure 11 rezone.

FIG. 1 is a block diagram for clearly showing the configuration of the present invention.

A supercharging section 3 for supercharging intake air is installed in the intake passage 2 of the engine 1, and supercharging pressure control means 4 for regulating the supercharging pressure from the supercharging gate 3 to a predetermined upper limit value is attached. This supercharging pressure control means 4 regulates the supercharging pressure when the supercharging pressure exceeds the upper limit value when there is a lot of exhaust gas and the exhaust gas temperature is high, such as in a high speed and high load state due to the operation of a waste gate valve. This suppresses and controls the boost pressure in the zone.

On the other hand, an ignition timing control means 6 is provided which outputs an ignition signal to the spark plug 5 of the engine 1 at a predetermined timing to control the ignition timing, and this ignition timing control means 6 includes an operation zone determination means 7.
A retard signal is output from the retard correction means 8 which receives the signal. This retardation correction means 8 operates in an operating zone other than the supercharging pressure regulation zone in a high rotation region where the supercharging pressure generated by the supercharging 13 is regulated to an upper limit value by the supercharging pressure control means 4, that is, the supercharging When the output request such as during acceleration in a region where the pressure has not reached the upper limit value is determined by the signal from the operating zone determination means 7, the ignition timing is retarded than the ignition timing in J3 in the boost pressure regulation zone. The correction is made so that

(Function) The ignition timing control device as described above retards the ignition timing from the ignition timing in the boost pressure regulation zone when output is requested when the boost pressure is below the upper limit regulation value, such as during acceleration in the low rotation range. The combustion state is changed to after-burning state Em to raise the exhaust gas temperature, thereby improving turbo efficiency and boosting pressure, thereby improving engine output.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is an overall configuration diagram of a specific example.

The combustion chamber 11 of the engine 1 has an intake boat 13 opened and closed by an intake valve 12 and an exhaust boat 15 opened and closed by an exhaust valve 14.
An intake passage 2 and an exhaust passage 16 are connected to the exhaust boat 15 and the exhaust boat 15, respectively.

A supercharging IFJI3 (separate turbocharging) is provided to supercharge intake air supplied from the intake passage 2 to the combustion chamber 11. This supercharging unit 3 includes a turbine 3a installed in the exhaust passage 16 and a blower 3b installed in the intake passage 2, and the two are connected. is driven to supercharge the intake air.

An air cleaner 17 and an air flow meter 18 are disposed in the intake passage 2 upstream of the blower 3b.
A throttle valve 19 is interposed in the intake passage 2 downstream of b, and a fuel injection nozzle 20 for injecting and supplying fuel toward the intake boat 13 is installed.

Further, a bypass passage 21 is provided to bypass the turbine 3a of the supercharging unit 3, and a wastegate valve 22 for adjusting the supercharging pressure is interposed in the bypass passage 21. The waste gate valve 22 is opened and closed by an actuator 23 that operates in response to filtration supply pressure generated in the intake passage 2 downstream of the blower 3b. On the other hand, fuel from a fuel tank 25 is supplied to the fuel injection nozzle 20 via a fuel pump 27 and a filter 28 through a fuel supply pipe 26, and the fuel pressure relative to the intake pressure is adjusted by a pressure regulator 29.

Further, an ignition plug 5 is disposed facing the combustion chamber 11 of the engine 1, and a lightning voltage from an igniter coil 30 is applied to the ignition plug 5.

Then, the ignition timing by the spark plug 5 and X! 5
The amount of fuel injected from the efficient injection nozzle 20 is controlled by a control signal output from a control unit 31. The control unit 31 includes, in order to detect the operating state of the engine 1, intake air carrier Shintan from the air flow meter 18, a throttle signal from a throttle opening sensor 32 that detects the opening of the throttle valve 19, and cooling water. A crank angle sensor 35 detects the water temperature signal from the water temperature sensor 33 that uses temperature, and the rotation angle of the crankshaft 34.
Crank angle signals are input from each.

The control unit 31 determines the operating state of the engine 1 from signals from various sensors, and determines the operating state of the engine 1 when the engine speed is in a relatively low speed range (for example, from 2500 rpm to idling speed) and when the throttle opening is large and the load is relatively high. During acceleration in an operating zone, the ignition timing is retarded, thereby causing engine combustion to enter an afterburning state and increasing the +JI gas temperature.

The operation of the control unit 31 will be explained based on the flowchart of FIG. After starting the engine,
In step S1, the intake air amount Qa is read from the output of the air flow meter 18, and the engine rotational speed Ne is input (S2). Then, in step S3, the intake air f
Basic injection time Tp from f1Qa and engine speed Ne
(injection pulse width). Note that K is a coefficient. Further, in step S4, the throttle opening sensor 32
Inputs the throttle signal Tvo from.

Step S5 determines whether the engine speed Ne is less than or equal to the second set value R2 on the high speed side, and step S6 determines whether the engine speed Ne is equal to or higher than the first set value R1 on the low speed side. It is something to do.

If the determination in step S5 is NO, the engine speed Ne is the second
If it exceeds the set value R2, that is, in the high rotation range, the rotation speed of the supercharging gate 3 is also high and the supercharging pressure is increased by the waste gate valve 22.
In the region regulated to the upper limit by the opening operation of
2, the ignition timing retard m TaCs is read and set to the acceleration correction value TaC (813).

On the other hand, if the determinations in steps S5 and S6 are YES and the engine speed Ne is between the first set value R1 and the second set value R2, the throttle opening Tv is determined in step S7.
It is determined whether O is within a predetermined range TV01 to TVO□.

This predetermined range is a load range in which the intake pressure is approximately near atmospheric pressure, and the intake air amount is not so large and the boost pressure is below the operating set pressure of the wastegate valve 22, that is, the upper limit value. If the determination in step S7 is YES, the process proceeds to step S8, and it is determined from the change in throttle opening, etc. whether or not it is in an acceleration state.If this determination is YES and it is in an acceleration state, the ignition is stopped in step S9 Read the timing retardation amount 78C2 and set it to the acceleration correction value 1'-ac (S10)
. If the determination in step s7 is No, the process proceeds to step S11 to determine whether or not the vehicle is in an acceleration state.

The angle fL TaC2 of the acceleration correction value read in step S9 is set to a large value with respect to the retardation amount T acl of the acceleration correction value during high rotation read in step 813.

After setting the acceleration correction value Tac as described above, the water 4THV is read in step 814, the water temperature correction value TV for the ignition timing is read in accordance with this water temperature THW in step 815, and the engine speed Ne and basic The basic ignition timing Tmap is read from the map of the injection time Tp. Then, in step S17, the final ignition timing T
ic+, the above basic ignition timing T map and acceleration correction value T
Based on aC and water temperature correction value T■ (0), step 820
An ignition signal is output to the igniter coil 30 at a predetermined time based on the crank angle No. 18.

Note that when the determination in step S6 is No and the engine speed NO is at low engine speed idling below the first set value R1, the fixed ignition timing Ts is read in step S18 and the ignition timing TI9 is set (519), and the output is output in step S20. It is something to do.

In the embodiment described above, the ignition timing is retarded when output is required, such as during acceleration, in an operating range where the boost pressure does not reach the upper limit based on the engine speed Ne and the throttle opening T VO < load. By correcting and delaying the combustion timing in the lower combustion chamber 11, the exhaust gas temperature is increased by I/V (approximately 30°C). The aim is to improve efficiency and increase boost pressure, thereby increasing engine output.

In the above embodiment, the state of boost pressure is determined indirectly from the engine speed and the operating state of the throttle opening, but it is determined directly from the operating state of the boost pressure or the wastegate valve. It may also be detected.

(Effects of the Invention) According to the present invention as described above, when the upper limit of the boost pressure is regulated by the boost pressure control means and the ignition timing is By making the retardation correction, it is possible to change the combustion state to an afterburning state and raise the exhaust gas temperature, which improves turbo efficiency, increases supercharging pressure, and improves engine output. It is possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for clarifying the configuration of the present invention, FIG. 2 is an overall configuration diagram of a specific example, and FIG. 3 is a flowchart for explaining the processing of a control unit. 1...Engine, 3...Supercharger, 4.
...Supercharging pressure control means, 5...Spark plug, 6...Ignition timing control txt+ means, 7...
...F stage for each driving zone, 8...Retard angle correction means, 31...Control unit. Figure 1,,'152 Figure 2i1; 3 1i1

Claims (1)

[Claims] (1) A supercharger is provided in the intake passage of the engine, and the supercharger is equipped with a supercharging pressure control means that regulates the upper limit of supercharging pressure in a predetermined operating zone, and an ignition timing control means that controls the ignition timing of the engine. In an ignition timing control device for a charged engine, an operating zone discriminating means for discriminating a zone where the boost pressure is lower than an upper limit boost pressure regulated by the boost pressure controlling means, and receiving a signal from the operating zone discriminating means; Retard correction means for outputting a correction signal for retarding the ignition timing from the ignition timing in the boost pressure regulation zone to the ignition timing control means when an output is requested in an operating range other than the boost pressure regulation zone. Features: Ignition timing control device for supercharged engines.