JP2530647B2 - Ignition timing control device for supercharged engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition timing control device for a supercharged engine.

(Prior Art) Conventionally, a turbocharger is installed in the intake passage of the engine to improve the engine output by supplying the supercharged air, while the upper limit of the supercharging pressure is set to a predetermined value from the aspect of engine reliability. There is known a supercharged engine equipped with a supercharging pressure control means for restricting to (see, for example, Japanese Utility Model Laid-Open No. 58-124619).

(Problems to be solved by the invention) When the upper limit of the supercharging pressure is regulated to a predetermined value as described above, a region where the supercharging pressure does not reach the upper limit value, for example, during acceleration in a low rotation range, etc. In the above, the engine output can be improved by increasing the supercharging pressure. In order to increase the supercharging pressure in such a region, it is sufficient to improve the turbo efficiency in the turbocharger. The turbo efficiency is proportional to the exhaust gas flow rate and proportional to the square of the exhaust gas temperature. The turbo efficiency is low because the exhaust gas flow rate is low and the exhaust gas temperature is low at the time of low-speed acceleration as described above, and the turbocharging pressure decreases accordingly, and the engine torque decreases. Is caused.

Therefore, in view of the above circumstances, the present invention has a supercharger for improving the engine output by improving the turbo efficiency by controlling the ignition timing at the time of output demand in a region where the supercharging pressure is low other than the supercharging pressure regulation zone. An object is to provide an ignition timing control device for an engine.

(Means for Solving Problems) The ignition timing control device of the present invention is provided with a supercharger including a supercharging pressure control means for regulating an upper limit of the supercharging pressure in a predetermined operation zone, and the supercharging pressure control means is provided. And a ignition zone at the time of requesting an output in an operation range other than the supercharging pressure regulation zone by receiving a signal from the driving zone discrimination means for discriminating a zone having a supercharging pressure lower than the upper limit supercharging pressure regulated by The control means is provided with retard correction means for outputting a correction signal for retarding the ignition timing from the ignition timing in the boost pressure regulation zone.

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

A supercharger 3 for supercharging intake air in the intake passage 2 of the engine 1.
Is installed, and supercharging control means 4 for restricting the supercharging pressure by the supercharger 3 to a predetermined upper limit value is attached. The supercharging pressure control means 4 has a large exhaust gas amount and a high exhaust gas temperature such as in a high rotation and high load state due to the operation of a wastegate valve, and the supercharging pressure regulation zone in which the supercharging pressure exceeds the upper limit value. It suppresses and controls the supercharging pressure at.

On the other hand, the ignition plug 5 of the engine 1 is provided with an ignition timing control means 6 for controlling the ignition timing by outputting an ignition signal at a predetermined timing. The ignition timing control means 6 receives the signal from the operating zone discriminating means 7. A retard signal is output from the angle correction means 8. The retard correction unit 8 operates in a driving zone other than the supercharging pressure regulation zone in the high rotation region where the supercharging pressure by the supercharger 3 is regulated to the upper limit value by the supercharging pressure control unit 4, that is, the supercharging pressure. When the output request time such as acceleration is determined by the signal from the operation zone determination means 7 in the region where the value does not reach the upper limit value, the ignition timing is retarded from the ignition timing in the boost pressure regulation zone. To correct.

(Operation) In the ignition timing control device as described above, the ignition timing is retarded with respect to the ignition timing in the supercharging pressure regulation zone when the supercharging pressure is required to be output at the upper limit regulation value or less, such as during acceleration. Then, the combustion state is changed to a post-combustion state to raise the exhaust gas temperature, thereby improving the turbo efficiency, increasing the supercharging pressure, and improving the engine output.

(Examples) Examples of the present invention will be described below with reference to the drawings. Second
The figure is an overall configuration diagram of a specific example.

An intake port 13 opened and closed by an intake valve 12 and an exhaust port 15 opened and closed by an exhaust valve 14 are opened in a combustion chamber 11 of the engine 1, and an intake passage 2 is provided in the intake port 13 and an exhaust port 15 is provided in the exhaust port 15. The exhaust passages 16 are connected to each other.

A supercharger 3 (turbo supercharger) that supercharges the intake air supplied from the intake passage 2 to the combustion chamber 11 is provided. The supercharger 3 includes a turbine 3a installed in the exhaust passage 16 and a blower 3b installed in the intake passage 2, both of which are connected to each other, and the blower 3b is rotated by the turbine 3a rotated by the energy of the exhaust gas. Is driven to supercharge intake air. An air cleaner 17 and an air flow meter 18 are provided in the intake passage 2 upstream of the blower 3b, a throttle valve 19 is provided in the intake passage 2 downstream of the blower 3b, and fuel is supplied toward the intake port 13. A fuel injection nozzle 20 for injecting and supplying is installed.

Further, a bypass passage 21 that bypasses the turbine 3a of the supercharger 3 is provided, and a wastegate valve 22 that adjusts the supercharging pressure is interposed in the bypass passage 21. The waste gate valve 22 is opened / closed by an actuator 23 that operates according to the supercharging pressure generated in the intake passage 2 downstream of the blower 3b. On the other hand, for the fuel injection nozzle 20, the fuel from the fuel tank 25 is supplied to the fuel supply pipe 26.
Is supplied via the fuel pump 27 and the filter 28, and the fuel pressure with respect to the intake pressure is regulated by the pressure regulator.
Adjusted by 29.

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

The ignition timing of the spark plug 5 and the fuel injection amount from the fuel injection nozzle 20 are controlled by a control signal output from the control unit 31. The control unit 31 includes an intake air amount signal from the air flow meter 18, a throttle signal from a throttle opening sensor 32 for detecting the opening of the throttle valve 19, a cooling water temperature in order to detect the operating state of the engine 1. A water temperature signal from a water temperature sensor 33 for detecting the crank angle and a crank angle signal from a crank angle sensor 35 for detecting the rotation angle of the crank shaft 34 are input.

The control unit 31 determines the operating state of the engine 1 from the signals of various sensors, and in a relatively low engine speed range (for example, from 2500 rpm to idle speed range), a large throttle opening and a relatively high load state. The ignition timing is retarded at the time of acceleration in the operating zone in which the exhaust gas temperature is raised by making the engine combustion into a post-combustion state.

The operation of the control unit 31 will be described with reference to the flowchart of FIG. After starting the engine,
Intake air amount from the output of the air flow meter 18 in step S1
While reading Qa, input the engine speed Ne (S2). Then, in step S3, the basic injection time Tp (injection pulse width) is calculated from the intake air amount Qa and the engine speed Ne. Note that K is a coefficient. Further, in step S4, the throttle signal Tvo from the throttle opening sensor 32 is input.

Step S5 determines whether the engine speed Ne is less than or equal to the second set value R ₂ on the high rotation side, and step S6 determines whether the engine speed Ne is greater than or equal to the first set value R ₁ on the low rotation side. Is determined. If the determination in step S5 is NO, the engine speed
When Ne exceeds the second set value R ₂ and is high, that is, in a region where the rotation speed of the supercharger 3 is high and the supercharging pressure is regulated to the upper limit value by the opening operation of the wastegate valve 22 in the high revolution range, The routine proceeds to S11, where it is determined whether or not the vehicle is in the accelerating state based on the change in the throttle opening degree, etc. When the accelerating state is YES, the ignition timing retard amount Tac ₁ is read in step S12 and the acceleration correction value Tac is set (S13).

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 R ₁ and the second set value R ₂ , the throttle opening Tvo is set to the predetermined range Tvo in step S7.
_It is determined whether it is within _{1 to} Tvo ₂ . This predetermined range is a load region where the intake pressure is substantially near atmospheric pressure, the intake air amount is not so large, and the supercharging pressure is the operating set pressure of the waste gate valve 22, that is, the upper limit or less. Step S7 above
If the determination is YES, the process proceeds to step S8, and it is determined whether or not the vehicle is in an accelerated state based on the change in the throttle opening.If the determination is YES, the ignition timing is retarded in step S9. Read the amount Tac ₂ and set it to the acceleration correction value Tac (S1
0). When the determination in step S7 is NO, the process proceeds to step S11 and it is determined whether or not the vehicle is in an acceleration state.

Relative retard amount Tac ₁ of the acceleration correction value at the time of high rotation to be written good at the step S13, the retard amount Tac ₂ of the acceleration correction value read in step S9 is set to a large value.

After setting the acceleration correction value Tac as described above,
The water temperature THw is read in 14 and the water temperature correction value Tw of the ignition timing is read in accordance with this water temperature THw in step S15, and the basic ignition timing Tmap is read from the map of the engine speed Ne and the basic injection time Tp in step S16. And step
In S17, the final ignition timing Tig is calculated from the basic ignition timing Tmap, the acceleration correction value Tac, and the water temperature correction value Tw, and step S
At 20, an ignition signal is output to the igniter coil 30 at a predetermined time based on the crank angle signal.

If the determination in step S6 is NO, the engine speed Ne
Is at the low speed idling below the first set value R ₁
The fixed ignition timing Ts is read in S18, the ignition timing Tig is set (S19), and output in step S20.

In the embodiment as described above, the ignition timing is retarded when output is required, such as during acceleration, in the operating region where the boost pressure does not reach the upper limit value from the engine speed Ne and the throttle opening Tvo (load). Then, the combustion timing in the combustion chamber 11 is delayed to raise the exhaust gas temperature (about 30 ° C.) to improve the turbo efficiency of the turbocharger 3 which has a characteristic proportional to the square of the exhaust gas temperature. By increasing the supply pressure, the engine output is improved.

In the above embodiment, the state of the supercharging pressure is indirectly determined from the operating state of the engine speed and the throttle opening, but it is directly determined from the supercharging pressure or the operating state of the wastegate valve. You may make it detect.

(Effect of the Invention) According to the present invention as described above, the ignition timing is set when the output is requested in an operating range in which the upper limit of the supercharging pressure is not regulated by the supercharging pressure control means and the supercharging pressure increases. By performing the retard correction, it is possible to raise the exhaust gas temperature by changing the combustion state to the post-combustion state, thereby improving the turbo efficiency, increasing the boost pressure, and improving the engine output. It is a thing.

[Brief description of drawings]

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 diagram for explaining processing of a control unit. 1 ... Engine, 3 ... Supercharger, 4 ... Supercharging pressure control means, 5 ... Spark plug, 6 ... Ignition timing control means, 7 ...
… Driving zone discrimination means, 8 …… Delay angle correction means, 31 …… Control unit.

Claims (1)

(57) [Claims] 1. A supercharger is provided in an intake passage of an engine, a supercharging pressure control means for regulating an upper limit of the supercharging pressure in a predetermined operation zone is provided, and an ignition timing control means for controlling an ignition timing of the engine is provided. In the ignition timing control device for an engine with a supercharger, an operating zone determining means for determining a zone having a supercharging pressure lower than an upper limit supercharging pressure regulated by the supercharging pressure controlling means, and a signal of the operating zone determining means are provided. received,
And a retard correction means for outputting a correction signal for delaying the ignition timing from the ignition timing in the boost pressure regulation zone to the ignition timing control means when an output request is made in an operating region other than the boost pressure regulation zone. A characteristic ignition timing control device for an engine with a supercharger.