JPH0412133A - Controller for supercharger of engine with mechanical supercharger - Google Patents

Abstract

PURPOSE:To prevent generation of shock by fluctuation in engine torque due to supercharge pressure increase by providing a shift ratio setting means for setting shift ratio of continuous variable transmission for controlling the number of revolutions of mechanical type supercharger according to the pressed down quantity of acceleration pedal. CONSTITUTION:A shift ratio setting means 50 is provided to which signals of acceleration opening sensors 22, crank angle sensor 23, and supercharger revolution speed sensor 24. The means 50 computes and sets the shift ratio of continuously variable transmission (C.V.T.) 14 according to engine speed as well as opening degree of accelerator. From a signal of the acceleration opening sensor 22, an acceleration judgement means 51 judges whether an engine 1 is in an acceleration mode or not. A shift speed setting means 52 to which the judgement result and the shift ratio are input sets the shift speed of the C.V.T. 14 moderate so as to gradually increasing the speed of the supercharger at the time of moderate acceleration, while the shift speed is set early so as to rise up the speed of supercharger rapidly at the time of rapid acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a supercharger control device for a mechanically supercharged engine, and more specifically, the present invention relates to a supercharger control device for a mechanically supercharged engine, and more particularly, to Regarding control of supercharger rotation speed during subsequent acceleration.

[Conventional technology]

Conventionally, in order to increase the output of an internal combustion engine, it is known that a mechanical supercharger (supercharger) is disposed within an intake passage. However, in this method, in order to control the supercharging pressure according to the engine load, a clutch device #R that turns on and off the drive of the supercharger and a bypass passage that bypasses the supercharger are installed. Therefore, when starting supercharging, the clutch is turned on and a shock occurs, and at high engine speeds, the intake capacity decreases, and in the region where the supercharger pump efficiency is high, the supercharging pressure increases too much. However, the boost pressure had to be bypassed, which resulted in problems such as an increase in supply air temperature and a loss of drive torque.

Further, in a supercharged engine, when an attempt is made to accelerate in a state where the spark plug temperature is low after fuel cut, there is a problem in that misfire occurs because the required voltage of the spark plug becomes high.

Therefore, as a countermeasure against these problems, for example, Japanese Patent Laid-Open No. 61-265
Publication No. 332 also discloses that the supercharging effect is weakened only during acceleration operation when the required voltage of the ignition system is high.
Japanese Patent Publication No. 272419 discloses that drivability during sudden acceleration can be improved while suppressing the occurrence of shock when switching the clutch or bypass. Furthermore, JP-A-60-842
No. 7 discloses that the engine is driven by an engine via a supercharger or a belt-type transmission.

[Problem to be solved by the invention]

By the way, the above-mentioned 1. The second prior art uses bypass control means to bypass the amount of air discharged from the supercharger in order to weaken the supercharging effect. Therefore, there are problems such as an increase in supply air temperature and driving loss.

Further, in the case of controlling a supercharger connecting clutch without having a bypass passage, there are problems such as burnout of the clutch.

Furthermore, in the third prior art, the supercharger is driven by the engine via a continuously variable transmission, but the supercharger accelerates in the low engine speed range and decelerates when the engine speed exceeds a predetermined speed. However, it does not perform control such as preventing a misfire or mitigating a sudden increase in torque during acceleration after one fuel cut.

The present invention has been proposed to address the above-mentioned problems, and is an automatic self-control system that enables the rotational speed of a supercharger to be controlled via a continuously variable transmission and prevents misfires during acceleration after a fuel cut. It is also an object of the present invention to provide a supercharger control device for a mechanical supercharger I-1 engine that can eliminate shock during acceleration.

[Means to solve the problem]

To achieve this objective, the present invention disposes a mechanical supercharger whose rotation is controlled from the engine crankshaft via a continuously variable transmission in the intake pipe downstream of the throttle valve connected to the accelerator pedal. In an engine in which the gear ratio of the continuously variable transmission is controlled and the rotation speed of the mechanical supercharger is controlled, the opening degree of the throttle valve is fully opened when the amount of depression of the accelerator pedal is equal to or greater than a predetermined amount of depression. an accelerator operating means; a first gear ratio setting for setting a gear ratio of the continuously variable transmission for controlling the rotational speed of the mechanical supercharger according to the amount of depression of the accelerator pedal; and a gear ratio setting means. slow acceleration by an acceleration determination means that determines the acceleration state of the engine;
a gear change speed setting means that is set based on a determination of sudden acceleration;
Under the fuel cut condition of the engine, the fuel cut return means determines whether the fuel cut has returned, and the fuel cut return determination means determines that the fuel has been restored, and the acceleration determination means determines that the fuel is being accelerated. The invention is characterized by comprising timer means for delaying the rise of the rotational speed of the mechanical supercharger for a predetermined period of time when the rotational speed of the mechanical supercharger is increased.

C action] The supercharger control device for an engine with a mechanical supercharger of the present invention has the following features:
When a slow acceleration state of the engine is detected, the continuously variable transmission changes gears slowly, so the supercharger rotation speed gradually increases, and the increase in supercharging pressure during slow acceleration causes Shocks due to torque changes are prevented.

Furthermore, when a sudden acceleration state is detected, the continuously variable transmission quickly changes gears, and the supercharger rotation speed quickly reaches a rotation speed corresponding to the engine load, resulting in excellent acceleration performance.

Further, during acceleration after returning from fuel cut, the supercharger rotation speed is set within a predetermined time period to be lower than the accelerator opening degree of the accelerator pedal, that is, the supercharger rotation speed corresponding to the engine load. Therefore, since the supercharging pressure is low for a predetermined period of time, the required voltage of the spark plug does not become large even when the temperature of the spark plug decreases during fuel cut, so misfires can be prevented.

〔Example〕

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

FIG. 2 is a schematic overall configuration diagram of an embodiment to which the present invention is applied. In the figure, reference numeral 1 is an engine, and 2 is an engine l
3 is an intake valve, 4 is an exhaust valve, 5 is an injector, 6 is a spark plug, 7 is an air cleaner, 8 is an air flow meter, 9 is an intake pipe, and 10 is a throttle body having a throttle valve 11. There is.

On the downstream side of the throttle valve 11, rotors 12a and 12b are installed.
A positive displacement supercharger 12 is provided.

In addition, 14 is a hydraulic continuously variable transmission, and its human power shaft 1
The human pulley 15a split into 5 parts is connected to the crankshaft 1 of the engine I via a winding transmission device 17 such as a belt chain.
The rotation speed of the human power shaft 15 is 1: the rotation speed of the crankshaft 1a.
1, and the rotational drive shaft 19 of the supercharger I2 is directly connected to the output shaft 16 of the continuously variable transmission 14, so that the rotation speed (rotation drive shaft 19) of the supercharger I2 is continuously variable. It is variably controlled by the gear ratio of the transmission 14. The rotational drive shaft 19 of the supercharger 12 is provided with a supercharger rotation speed sensor 24 that detects the rotation speed of the supercharger I2.

Furthermore, the accelerator operating means 13 of the throttle valve 11 includes:
A throttle lever Ha is provided, and a throttle lever 1 is provided.
3a and the accelerator pedal 20 are interlocked and connected by an accelerator wire 21. And as shown in Figure 4,
The opening degree θ of the throttle valve 11 is set to be fully open depending on the depression amount ψ1 of the accelerator pedal 20 in region A during extremely low load, and the opening degree θ of the throttle valve 11 changes according to the depression amount ψ of the accelerator pedal 20. is controlled to open and close. Additionally, an accelerator opening sensor 22 detects the amount of depression of the accelerator pedal 20.
At the same time, a crank angle sensor 23 is installed on the crankshaft 1a of the engine 1 to detect the engine rotation speed Ne.
Or is provided.

The continuously variable transmission 14 has a human power shaft 15 and an output shaft 16 parallel to the human power shaft 15, as shown in FIG. A primary pulley 30 is provided on the output shaft 16, and a secondary pulley 31 similarly provided with a secondary cylinder 31a is provided on the output shaft 16. Also, the primary pulley 30. A drive belt 32 is wound around the secondary pulley 31, and the primary cylinder 30a and the secondary cylinder 31a are configured in a hydraulic control circuit 60. Line pressure corresponding to the transmission torque is supplied to the secondary cylinder 31a to apply a pulley pressing force, and the primary pressure causes the primary pulley 30. of the drive belt 32 to be pressed. The winding of the secondary pulley 31 by .chi.1 is configured to change the ratio of diameters to perform stepless speed change control.

Further, the primary pulley 30 of the continuously variable transmission 14 includes a primary booster rotational speed sensor 33 that detects the primary booster rotational speed Np, and the secondary pulley 31 includes a secondary booster rotational speed sensor 33 that detects the secondary booster rotational speed Ns. Sensors 34 are respectively arranged, and these primary boolean rotation speed sensors 33 . Secondary boolean rotation speed sensor 3
The signals Np and Ns from the accelerator opening sensor 22.
The signals ψ and Nc from the crank angle sensor 23 are input to the control unit 40.

And the ratio N between the engine speed Ne and the supercharger speed Nc
The gear ratio i, which is e/Nc, is equal to the ratio Np/Ns of the primary pulley rotation speed Np and the secondary pulley rotation speed Ns of the continuously variable transmission 14, i −Ne/Nc−Np/N
It is s.

Next, the supercharger 12 is constructed based on FIGS. 1, 2, and 3.
This section describes the rotation speed control system.

The control unit 40 is configured as a microcomputer system for controlling each control element of the engine l. The control unit 40 is a central processing unit (CPU)
41. RAM42 and ROM43 as memory
．． It consists of an input/output device (Ilo) 44 and a bus 45 that connects them. The output port of l1044 is connected to the drive circuit 46.

! The input port 1044 is connected to an accelerator opening sensor 22. which detects the depression amount ψ of the accelerator pedal 22. Crank angle sensor 23° for detecting engine speed Ne Supercharger I2
A supercharger rotation speed sensor 24. detects the rotation speed Nc of the supercharger rotation speed sensor 24. and injector 5 or primary pulley rotation speed sensor 33 to detect fuel cut/return. The secondary pulley rotation speed sensor 34 is connected, and the drive circuit 4G is connected to the hydraulic control circuit 60 of the continuously variable transmission I4.

As shown in FIG. 1, each signal of the accelerator opening sensor 22, crank angle sensor 23 (or primary pre-rotation speed sensor 33), and supercharger rotation speed sensor 24 (or secondary boost rotation speed sensor 34) is input manually. The gear ratio setting means 50 determines the amount of depression of the accelerator pedal 20 and the accelerator opening ψ corresponding to the negative 6:j of the engine l from a map preset by the gear ratio setting means 50. The gear ratio 1 of the continuously variable transmission 14 is calculated and set by i - Nc/Nc (Np/Ns) based on the engine rotation speed Ne.

The signal from the accelerator opening sensor 22 is manually input to the acceleration determining means 51, and the acceleration determining means 51 determines whether or not the engine 1 is accelerating based on the rate of change in the amount of depression of the accelerator pedal 20 α=dψ/dt. It also has a speed change setting means 52 into which the speed change ratio i and an acceleration signal are input, and the speed change speed setting means 52 is used to gradually increase the supercharger rotation speed Nc when the acceleration is slow. , the shift speed dt/ of the continuously variable transmission I4
dt is set gently, and during sudden acceleration, the supercharger rotation speed Nc
In order to start up quickly, the shift speed di/dt is set to be fast.

Furthermore, it has a fuel cut return determination means 53 which manually receives a signal from the injector 5, and the fuel cut return determination means 5
In step 3, it is determined whether the fuel supply state to the injector 5 has returned to the fuel supply state from the fuel supply stop state.

When a fuel cut return signal and an acceleration signal are input manually to the speed ratio setting means 50, the speed ratio setting means 50 sets the supercharger rotational speed Nc+ for a predetermined period of time by the timer means 54.
The predetermined rotation speed Δ is determined from the rotation speed Nc corresponding to the accelerator opening degree ψ.
In order to set the rotation speed to be N lower, the gear ratio i of the continuously variable transmission 14 is set to i-i, +Δ1. Then, after a predetermined period of time has elapsed, the gear ratio i changes to i-i, and the supercharger rotational speed N
c is set to the rotation speed corresponding to the accelerator opening degree ψ.

To describe the operation of the supercharger control with this configuration, in the extremely low load region A, which includes the idling state when the vehicle is stopped and the accelerator pedal 20 is released, the continuously variable speed #if
The gear ratio i of 4 is set large, and the secondary pulley 31
The rotational speed of the supercharger 12, that is, the rotational speed of the supercharger 12, is controlled to a predetermined constant low rotational speed. On the other hand, the throttle valve 11 is controlled to open and close according to the amount of depression ψ of the accelerator pedal 20, and controls the amount of air discharged from the supercharger 12.

In the state of extremely low load 6.1, the accelerator pedal is 20
When the operator depresses the accelerator pedal 20, the throttle valve 11 is fully opened, and the output shaft 16 of the continuously variable transmission 14 is increased in speed according to the accelerator opening degree ψ caused by depressing the accelerator pedal 20 as shown in FIG. The power of the engine 1 in response to the depression of the accelerator pedal 20 is transmitted to the crank 1a and the crank pulley 1.
8. The signal is transmitted to the continuously variable transmission 14 via the input terminal 58 of the continuously variable transmission 14.

The power manually applied to the primary pulley 30 of the continuously variable transmission 14 is transferred to the secondary pulley 3 via the drive heald 32.
1. It is transmitted to the output shaft 16 and the drive shaft 19 of the supercharger 12.
The supercharger 12 is driven to increase its speed, and the intake air is supplied to the engine l.

Outside the extremely low load range, as the engine torque increases, the line pressure of the continuously variable transmission 14 is set to a higher value, and is controlled by inputting a corresponding duty signal or a line pressure control solenoid valve (not shown). The line pressure is increased by generating pressure and controlling the line pressure using the averaged pressure. As the gear ratio i becomes smaller and the engine torque also becomes smaller, the line pressure is controlled to be lower due to the same effect.In this way, the pulley pressing force is always equivalent to the transmission torque of the drive belt 32. to act.

The line pressure is always supplied to the secondary cylinder 31a, and the gear change is controlled by supplying and draining oil to the primary cylinder 30a by a shift control valve (not shown) using the control pressure of a shift control solenoid valve (not shown).

Therefore, in the A region in FIG. 4, that is, in the extremely low load region, the gear ratio of the continuously variable transmission 14 is set small so that the rotation speed of the supercharger 12 is a low constant predetermined rotation speed,
The supercharger I2 is driven at a predetermined rotation speed and discharges a constant amount of air, and the amount of discharged air is controlled by opening and closing the throttle valve 11 according to the amount of depression of the accelerator pedal 20.

Next, in the low/medium load region of the 86M range, the throttle valve 11 is fully opened by depressing the accelerator pedal 20.
Continuously variable transmission 14 according to the amount of depression of accelerator pedal 20 ψ
By changing the speed ratio of the supercharger 12, the rotation speed of the supercharger 12 is controlled, and the intake air amount is controlled by the rotation speed of the supercharger 12. At this time, the upstream pressure of the supercharger 12 is approximately atmospheric pressure,
The downstream pressure becomes negative pressure due to the intake action of the engine, and the pressure angle ratio (discharge side pressure/intake side pressure angle) of the supercharger 12 becomes “
1", and as shown in the characteristic diagram of pressure ratio and driving force in FIG. The transmission is recovered, reducing fuel consumption.

Furthermore, the high load area of the C area is a supercharging area, and the rotation speed of the supercharger I2 increases and the engine output increases so that the necessary boost pressure can be obtained according to the amount of depression of the accelerator pedal 2o. do.

In addition, in the above embodiment, the opening and closing of the throttle valve 11 is as follows.
The accelerator operating means 13 may be configured to be electrically controlled instead of using a mechanical link device linked to the accelerator pedal 2o.

FIG. 6 is a flowchart showing the supercharger rotation speed control routine. In step s1 old, the engine rotation speed Ne,
Supercharger rotation speed Nc, accelerator opening ψ.

Alternatively, the primary pulley rotation speed Np and the secondary pulley rotation speed Ns are read. Then, in step 5102, the gear ratio i is calculated from the map set by the target supercharger rotation speed Ncs corresponding to the accelerator opening ψ and the engine rotation speed Ne as i=Nc/Ncs. .

A gear ratio control signal and a line pressure control signal for controlling the gear ratio of the continuously variable transmission 14 based on this gear ratio i are input to the hydraulic control circuit 60, and the continuously variable transmission 14 is hydraulically controlled and the secondary pulley rotation speed is NS is made equal to the target supercharger rotation speed Ncs, resulting in Nc - Ns - NC8.

In step S1.03, a shift speed di/dt for shifting to the gear ratio i is calculated.

In step 5104, the opening/closing speed dψ of the accelerator opening degree ψ
/dt and the first set value α1 are compared, and dψ/dt≧α
When it is 1, it is judged as acceleration.

In step 5105, the opening/closing speed dψ/dL is compared with the S2 set value α2, and when dψ/dt≦α2, it is determined that the acceleration is slow, and the process proceeds to step 5I06, and when dψ/dt≧α2, it is determined that the acceleration is rapid. The process then proceeds to step 5107.

In step 8106, since the acceleration is slow, the speed change speed di/dt at which the speed is changed to the speed ratio j is decreased. Therefore, since the continuously variable transmission 14 is controlled to change speed slowly, the supercharger rotational speed Nc gradually increases.

In step 5107, the speed change speed di/dt for changing to the speed ratio 1 is increased due to sudden acceleration. Therefore, the speed change control of the continuously variable transmission 14 is accelerated, and the supercharger rotational speed Nc is increased quickly.

Further, when dψ/dt≦α1 in step 5104, that is, when there is no acceleration, the process proceeds to step 5108, and the gear ratio i
The gear shifting speed di/dL is the opening/closing speed d of the accelerator.
The shifting speed corresponds to ψ/dt. Therefore, the continuously variable transmission 14 changes speed at a predetermined speed.

FIG. 7 is a flowchart showing an interrupt routine for supercharger rotation speed control. In step S201, it is determined whether or not the fuel supply to the injector 5 is cut, and when it is determined that the fuel is cut, the process proceeds to step 5202. It is determined whether or not fuel has been supplied to the injector 5 again (whether fuel cant has returned or not), and if fuel cut has been returned, the process advances to step 5203.

In step 5203, the opening change speed dψ/dL of the accelerator opening ψ is compared with the set value a, and dψ/(IE≧a
When , it is determined that acceleration is occurring, and the process advances to step 5204.

In step 5204, the timer count value is counted up (C+ "C+ +1."). Then, in step 5
In step 205, the gear ratio change flag Fi is set as the gear ratio change condition of Ft -1, and in step 5206, the gear ratio i is set to reduce the supercharger rotational speed Nc for a predetermined period of time during acceleration after returning from the fuel cut. Increase the gear ratio by a predetermined amount Δi (i−i1+Δi).

In step 5207, the timer count value C1 and the set value C5Ea are compared, and when the condition is Cl-C3F, the process proceeds to step 5208, where Fi-0 is set and the normal gear ratio control condition is set.

Furthermore, if it is determined in step 5203 that there is no acceleration of dψ/dL <α, the process proceeds to step 5209, where the timer count value is cleared (C, -0), and the process proceeds to step 5208, where the normal shift control condition is set. .

Therefore, during slow acceleration, it takes longer for the supercharger rotation speed to reach the regular rotation speed, and the shock caused by the torque change of Ennon I due to the supercharging pressure -H is prevented. During sudden acceleration, the time it takes for the supercharger rotation speed to reach a steady rotation speed becomes shorter, and the boost pressure increases quickly, resulting in better acceleration.

In addition, during acceleration after fuel exhaustion and return, the supercharger rotation speed Nc is set to a rotation speed lower than the accelerator opening ψ for a predetermined time, that is, the supercharger rotation speed corresponding to the engine load, and the supercharger rotation speed 12 is driven by engine 1 via continuously variable transmission I4, and engine 1 operates without misfire.

〔Effect of the invention〕

As explained above, according to the present invention, the opening degree of the throttle valve is controlled by an accelerator operation means that fully opens when the amount of depression of the accelerator pedal is equal to or more than a predetermined amount of depression, and a mechanical override that changes the opening degree of the throttle valve according to the amount of depression of the accelerator pedal. Since it has a gear ratio setting means for setting the gear ratio of the continuously variable transmission for controlling the feeder rotational speed, the supercharger in a steady state corresponds to the turbocharger rotational speed or accelerator opening during slow acceleration. Since the rotation speed is reached slowly, the boost pressure
[Engine due to elevation]・Shock or prevention due to lux change 1
1, and during sudden acceleration, the supercharger rotation speed quickly becomes constant 'J: (
The speed is the same as the supercharger rotation speed in the current state, which improves acceleration.

Furthermore, under fuel cut conditions of the engine, a fuel cut return means for determining fuel cut return, and a mechanical It has a timer means for delaying the rise of the turbocharger rotational speed for a predetermined period of time, so that when accelerating after returning from fuel cut, the supercharger rotational speed is lower than the supercharger rotational speed in a steady state by a predetermined period of time. Since the engine speed is set to the rotational speed, the required voltage of the spark plug is not too high and the spark plug will not misfire.

[Brief explanation of the drawing]

Fig. 1 is a block diagram according to the present invention, Fig. 2 is a schematic overall block diagram of an embodiment to which the present invention is applied, Fig. 3 is a block diagram of a control system of a continuously variable transmission, and Fig. 4 is a block diagram of an accelerator pedal depression. Figure 5 is a characteristic diagram showing the relationship between - and the throttle valve opening and the gear ratio of the continuously variable transmission. Figure 5 is a characteristic diagram showing the relationship between the pressure ratio of the supercharger and the driving torque. Figures 6 and 7 are FIG. 2 is a flowchart illustrating fi use of speed change control based on an acceleration state. FIG. Engine, Ia crankshaft, 9...intake pipe, II...
- Throttle valve, 12 Mechanical supercharger, 13... Accelerator operation means, 14 Continuously variable transmission, 20- Accelerator pedal, 22 Accelerator opening sensor, 23 Crank angle sensor, 24 Supercharger rotation speed sensor , 40 control unit, 50. Gear ratio setting means, 51. Acceleration 111 fixed stage, 52. Shift speed setting means, 53. Fuel cut return determination lower stage, 54. Timer means. Patent applicant: Fuji Heavy Industries Co., Ltd. 1 Agent: Nobu Kobashi Jundo, patent attorney

Claims (2)

[Claims] (1) A mechanical supercharger whose rotation is controlled from the engine crankshaft via a continuously variable transmission is installed in the intake pipe downstream of the throttle valve connected to the accelerator pedal, and the speed of the continuously variable transmission is changed. In an engine that controls a ratio and a rotation speed of the mechanical supercharger, the throttle valve is fully opened when the amount of depression of the accelerator pedal is equal to or more than a predetermined amount of depression of the accelerator pedal; a gear ratio setting means for setting a gear ratio of the continuously variable transmission for controlling the rotational speed of the mechanical supercharger according to the amount of depression of the accelerator pedal; a shift speed setting means for setting a shift speed of the continuously variable transmission to be shifted based on a determination of slow acceleration or sudden acceleration by an acceleration determination means for determining an acceleration state of the engine; a fuel cut return means for determining cut return; and a fuel cut return means for determining the rotation speed of the mechanical supercharger when the fuel cut return determination means determines that fuel has been restored and the acceleration determination means determines acceleration. 1. A supercharger control device for a mechanical supercharged engine, comprising timer means for delaying start-up for a predetermined period of time. (2) The speed change setting means controls the speed change speed of the continuously variable transmission to be slow when the acceleration determination means determines that the acceleration is slow;
2. The supercharger control device for a mechanically supercharged engine according to claim 1, wherein the speed change speed of the continuously variable transmission is controlled quickly when sudden acceleration is determined.