JPH05312067A - Internal combustion engine controller - Google Patents

Abstract

PURPOSE:To prevent such a possibility that engine starting might come to a difficulty or be impossible from occurring in the case where a throttle valve in an internal combustion engine is controlled by an electrical actuator and thereby sped control is performed. CONSTITUTION:This controller is provided with a control command signal generator circuit 13, generating a starting time control command signal Vcs for a while till the starting of an engine 1 is completed, and after starting completion, generating a steady time control command signal Vcn instead, and a manipulated variable signal selector circuit 14 selecting a manipulated variable signal according to the command signal. When the starting time control command signal is generated, a starting time manipulated variable signal Vds is selected by the circuit 14 and opening of a throttle valve is controlled so as to keep it to the setting opening in time of starting. When the engine starting is completed and the steady time control command signal is generated, a steady time manipulated variable signal Vdn is selected by the circuit 14 and thereby engine speed is controlled so as to be kept to the indicated engine speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control device for controlling a rotational speed of an engine by operating a throttle valve of the internal combustion engine with an electric actuator.

[0002]

2. Description of the Related Art As an internal combustion engine controller for controlling the rotational speed of an internal combustion engine, a throttle valve of a carburetor, which serves as a fuel supply amount adjusting unit of the engine, is operated by an electric actuator to adjust the opening of the throttle valve. By doing so, the rotation speed is controlled so as to be maintained at a desired command speed.

FIG. 6 is a block diagram showing a schematic configuration of a conventional internal combustion engine control device of this type. In this conventional control device, the rotational speed of the internal combustion engine 1 is detected by a speed detection circuit 4. The speed detection signal Vn obtained from the speed detection circuit is given to the speed deviation calculation circuit 6 together with the instructed speed signal Vno output from the speed instruction circuit 5 for setting the instructed rotational speed of the internal combustion engine. The speed deviation calculation circuit 6 calculates the deviation between the rotation speed of the internal combustion engine 1 and the designated rotation speed, and outputs a deviation signal (Vno-Vn). The manipulated variable calculating circuit 7 is an actuator 3 required to make the deviation between the rotational speed of the internal combustion engine 1 and the command rotational speed zero from the deviation signal (Vno-Vn).
Is calculated to output a manipulated variable signal Vd, and this manipulated variable signal Vd is applied to the actuator drive circuit 8. The actuator drive circuit 8 has a drive current Id for obtaining an operation amount required for the actuator 3 in accordance with the operation amount signal Vd.
To supply. As a result, the actuator 3 operates the throttle valve 2 to adjust the opening thereof, so that the rotation speed of the internal combustion engine 1 matches the command rotation speed.

[0004]

As described above, based on the speed detection signal and the instructed speed signal, the operation amount of the actuator required to make the deviation between the rotational speed of the internal combustion engine and the instructed rotational speed zero can be obtained. In the conventional control device that calculates and controls the opening of the throttle valve according to the operation amount signal obtained from this, the operation amount of the actuator is maximized when the internal combustion engine is started and the throttle valve is fully opened. It becomes a state. Generally, in a carburetor used in a general-purpose internal combustion engine, etc., the fuel flow system is set so that the air-fuel ratio becomes optimum near the rated rotation speed, so the throttle valve is fully opened when starting an engine with a low rotation speed. In this state, the air-fuel mixture becomes lean, and it becomes difficult to ignite and burn the air-fuel mixture especially at low temperatures. Therefore, there is a problem that it becomes difficult to start the engine when the conventional control device is used.

An object of the present invention is to provide an internal combustion engine control device capable of preventing the air-fuel mixture from becoming lean at the time of starting the internal combustion engine and improving the startability of the engine.

[0006]

As shown in FIG. 1 showing an embodiment of the present invention, an electric throttle valve 2 for adjusting the amount of fuel supply (inflow of air-fuel mixture) to an internal combustion engine 1 is electrically operated. The present invention relates to an internal combustion engine controller that controls an engine 3 to rotate the engine at an instructed speed.

The control device of the present invention comprises a speed detection circuit 4 and
Speed instruction circuit 5, speed deviation calculation circuit 6, steady state operation amount calculation circuit 7, throttle opening detection circuit 9, starting throttle opening setting circuit 10, starting operation amount calculation circuit 11, start Completion speed setting circuit 12, control command signal generation circuit 13, operation amount signal selection circuit 14, and actuator drive circuit 8.

The speed detection circuit 4 detects the rotational speed of the internal combustion engine and outputs a speed detection signal Vn, and the speed instruction circuit 5
A command speed signal Vno for setting a command rotation speed of the internal combustion engine is output. The speed deviation calculation circuit 6 receives the speed detection signal Vn and the instruction speed signal Vno as input, calculates the deviation between the rotation speed of the internal combustion engine and the instruction rotation speed, and outputs a deviation signal Vno-Vn.

From the deviation signal, the steady state operation amount calculation circuit 7 calculates the operation amount of the actuator required to make the deviation between the rotation speed of the internal combustion engine and the instructed rotation speed zero, and calculates the steady state operation amount signal Vdn. Is output.

The throttle opening detection circuit 9 detects the opening of the throttle valve 2 to detect a throttle opening detection signal Vi.
Then, the starting throttle opening degree setting circuit 10 outputs a starting throttle opening degree setting signal Vio corresponding to the set throttle opening degree at the time of starting the internal combustion engine.

The starting manipulated variable calculation circuit 11 includes a starting throttle opening setting signal Vio and a throttle opening detection signal Vi.
Is input to calculate the operation amount of the actuator 3 required to make the deviation between the throttle opening amount and the set throttle opening amount at the time of starting zero, and output the starting operation amount signal Vds.

The start completion speed setting circuit 12 sets the start completion speed of the internal combustion engine and outputs a start completion speed setting signal Vns.

The control command signal generation circuit 13 inputs the speed detection signal Vn and the start completion speed setting signal Vns and outputs the start control command signal Vcs until the rotation speed of the internal combustion engine reaches the start completion speed, and the internal combustion engine After the engine speed once exceeds the start completion speed, the steady-state control command signal Vcn is output.

The manipulated variable signal selection circuit 14 is operated when the start control command signal Vcs is generated.
Is selected, the steady-state operation amount signal Vdn is selected when the steady-state control command signal Vcn is generated, and the selected operation amount signal is given to the actuator drive circuit 8.

The actuator drive circuit 8 supplies a drive current to the actuator 3 in accordance with the operation amount signal selected by the operation amount signal selection circuit 14.

[0016]

In the above structure, the steady-state manipulated variable calculation circuit 7
Outputs a steady-state operation amount signal Vdn, and a start-time operation amount calculation circuit 11 outputs a start-time operation amount signal Vds. When the internal combustion engine 1 is started, the operation amount signal selection circuit 14 selects the startup operation amount signal Vds until the engine rotation speed reaches the start completion speed set by the start completion speed setting circuit 12. The actuator drive circuit 8 supplies a drive current to the actuator 3 according to the operation amount signal Vds at the time of starting. At this time, the actuator operates the throttle valve by an amount corresponding to the set throttle opening at the time of starting.

After the rotation speed of the internal combustion engine 1 rises and once exceeds the start completion speed, the operation amount signal selection circuit 14 selects the steady state operation amount signal Vdn, so that the actuator drive circuit outputs the steady state operation amount signal. Actuator 3 according to Vdn
Drive current is supplied to. At this time, the actuator operates the throttle valve 2 so that the rotation speed of the internal combustion engine 1 matches the instructed rotation speed.

Therefore, the set throttle opening at the start is
If the air-fuel ratio of the air-fuel mixture is selected to be appropriate at the time of starting the internal combustion engine 1 (for example, in a half-open state), the throttle opening is set to an appropriate air-fuel ratio until the engine reaches the start completion speed. Since it can be maintained in a size that can obtain, the starting of the engine can be facilitated. After the engine rotation speed once exceeds the start completion speed, the steady-state operation amount signal is selected, so the throttle valve 2 is operated so that the rotation speed of the internal combustion engine 1 becomes the instructed speed.

[0019]

1 shows the overall construction of an embodiment of the present invention, in which 1 is an internal combustion engine (a gasoline engine in this example) and 2 is a fuel mixture for the internal combustion engine. It is a throttle valve provided in the vaporizer. The throttle valve 2 is operated by an electrically driven actuator 3. Therefore, the valve opening changes according to the drive current Id of the actuator 3, and the inflow amount of the fuel mixture into the internal combustion engine 1 is adjusted.

FIG. 2 schematically shows an example of the structure of the throttle valve 2 and the actuator 3. The throttle valve 2 includes a butterfly valve 201, a rotary shaft 202 for supporting the butterfly valve, and a rotary shaft 202. A lever 203 fixed to one end is provided, and the valve is opened and closed by operating the lever 203. The actuator 3 used in this example is of a rotary solenoid type and has a pair of opposing magnetic pole portions 30.
A substantially U-shaped stator core 301 having 1a and 301a
A movable element 303 having a stator in which an exciting coil 302 is wound around a part of the rotor, a magnetic pole portion facing the magnetic pole portion 301a of the stator via a small gap, and rotatably supported. It is composed of a lever 304 fixed to the child and a spring 305 which gives a restoring torque proportional to the displacement angle θa when the movable element rotates.

A driving torque, which is substantially proportional to the driving current Id flowing through the exciting coil 302, is generated in the mover 303 of the actuator, and the mover 303 uses this drive torque and the spring 30.
It stops by rotating to a position where the restoring torque of 5 is balanced.

The lever 203 of the throttle valve 2 and the lever 304 of the actuator 3 are connected by a connecting rod 306, and the butterfly valve 201 of the throttle valve rotates in response to the rotation of the movable element 303 of the actuator. As shown in, the throttle valve opening θt
Is displaced substantially in proportion to the drive current Id of the actuator.

In FIG. 1, the speed detection circuit 4 comprises a rotation speed sensor 401 and a frequency voltage conversion circuit (F / V conversion circuit) 402. Rotation speed sensor 4
Reference numeral 01 is a sensor for detecting the rotation speed of the internal combustion engine. As this sensor, for example, a pickup coil attached to the internal combustion engine and generating a voltage of frequency f proportional to the rotation speed of the engine is used. Further, in the case of a gasoline engine provided with an ignition device, one of the ignition coils of the ignition device is
Since the frequency of the voltage induced in the secondary coil is proportional to the rotation speed, the primary coil of the ignition coil can also be used as a rotation speed sensor. Frequency voltage conversion circuit 40
Reference numeral 2 converts the frequency of the output of the sensor 401 into a voltage and outputs a speed detection signal Vn proportional to the rotational speed of the engine.

Reference numeral 5 denotes a speed instruction circuit for setting a desired instruction rotational speed for the internal combustion engine and outputting an instruction speed signal Vno having a voltage corresponding to the instruction rotational speed. This speed instruction circuit is, for example, a constant DC voltage. Can be divided by a resistance voltage divider including a variable resistor, and the divided voltage can be output as an instruction speed signal Vno.

The speed detection signal Vn and the instructed speed signal Vno
Are input to the speed deviation calculation circuit 6. The speed deviation calculation circuit 6 calculates the deviation between the actual rotation speed of the internal combustion engine and the designated rotation speed from the speed detection signal Vn and the designated speed signal Vno, and outputs a deviation signal (Vno-Vn).

The deviation signal Vno-Vn is given to the steady state manipulated variable calculation circuit 7. This arithmetic circuit outputs the deviation signal Vno.
In steady state, the operation amount of the actuator 3 (driving current Id of the actuator 3) required to make the deviation between the actual rotation speed of the internal combustion engine and the command rotation speed zero from -Vn is calculated to obtain this operation amount. The manipulated variable signal Vdn is output. The steady state manipulated variable circuit 7 is similar to the manipulated variable computing circuit used in the conventional control device of this type, and is composed of a proportional, integral and differential computing circuit.

A throttle opening detection circuit 9 detects the opening of the throttle valve 2 and outputs a throttle opening detection signal Vi. In this embodiment, it is connected in series to the exciting coil 302 (see FIG. 2) of the actuator 3. The throttle opening detection circuit 9 is constituted by the resistance R1 which is opened, and the voltage generated across the resistance R1 by the driving current Id of the actuator which is proportional to the opening θt of the throttle valve is used as the throttle opening detection signal Vi = R1 Id. It is like this.

Reference numeral 10 denotes a starting throttle opening setting circuit for setting a throttle opening at starting of the internal combustion engine. This setting circuit is a starting throttle opening setting signal corresponding to the throttle opening at starting of the internal combustion engine. Output Vio. As shown in FIG. 4, the starting throttle opening degree setting circuit 10 divides a constant DC voltage Vb by a voltage dividing circuit composed of resistors R2 and R3, and uses the divided voltage as a starting throttle opening degree setting signal Vio. It can be configured by an output circuit.

The throttle opening detection signal Vi and the starting throttle opening setting signal Vio are input to the starting manipulated variable calculating circuit 11. The starting operation amount calculation circuit 11 is an actuator required to make the deviation between the actual throttle opening and the set throttle opening at the time of starting from zero from the throttle opening detection signal Vi and the starting throttle opening setting signal Vio. The operation amount of 3 is calculated and the operation amount signal Vds at the time of starting is output.

As shown in FIG. 4, the starting manipulated variable calculating circuit 11 includes an operational amplifier OP1 for impedance conversion,
Operational amplifier OP2 and resistor R4 constituting an adder / subtractor circuit
An adder / subtractor 111 composed of R9, a resistor R10 and an integrating capacitor C, and an operational amplifier OP as an impedance converter.
3 and an integrating circuit 112 composed of The output Vds of the integrating circuit 112 is supplied to the operational amplifier O through the resistor R6.
It is fed back to the input side of P2. Adder / subtractor 1
Reference numeral 11 is an output signal Vo = α (Vio-V
i) + Vds [α is a proportional constant] is output. Since the potential difference between both ends of the resistor R10 is Vo-Vds = α (Vio-Vi), the output of the integrating circuit 112 (starting operation amount signal) obtained by integrating the current flowing through the resistor R10 by the integrating capacitor C is Vds = (α / R10C) ∫ (Vio-Vi) dt. When the actuator 3 is operated according to this signal Vds, the signal Vds continues to change until Vio-Vi becomes zero and stabilizes when Vi = Vio, and the opening of the throttle valve 2 is set to the set throttle opening at the time of starting. Holds every time.

In FIG. 1, reference numeral 12 is a start completion speed setting circuit, and this start completion speed setting circuit is an instruction speed signal Vno.
Is set as an input and a start completion speed is set, and a start completion speed setting signal Vns proportional to the speed instruction signal is output. Again 13
Is a control command signal generation circuit, which receives the speed detection signal Vn and the start completion speed setting signal Vns and outputs a start control command signal until the rotation speed of the internal combustion engine reaches the start completion speed, After the rotation speed of the internal combustion engine once exceeds the start completion speed, the steady-state control command signal is output.

FIG. 5 shows a concrete configuration example of the start completion speed setting circuit 12 and the control command signal generating circuit 13,
In the figure, the start completion speed setting circuit 12 is composed of an operational amplifier OP4 as an impedance converter and a voltage divider composed of resistors R11 and R12 for dividing the commanded speed signal Vno obtained at the output terminal of this operational amplifier. The divided voltage of the instruction speed signal Vno is output as the start completion speed setting signal Vns.

The control command signal generating circuit 13 includes a comparator CO
Comprising MP1 and resistor R13, the start completion speed setting signal Vns is input to the non-inverting input terminal of the comparator COMP1, and the speed detection signal Vn is input to the inverting input terminal of the comparator COMP1. Until the rotation speed of the internal combustion engine reaches the start completion speed, Vn≤Vns, so the comparator COM
The output terminal of P1 becomes high level, and the high level output becomes the start control command signal Vcs. Further, once the rotational speed of the internal combustion engine exceeds the start completion speed and becomes Vn> Vns, the output terminal of the comparator COMP1 becomes low level (or zero level) and this low level (or zero level) output is output. It becomes the constant control command signal Vcn. The feedback resistor R13 connected between the output terminal of the comparator COMP1 and the non-inverting input terminal prevents the hunting phenomenon from occurring when the output level of the comparator COMP1 is inverted, and also provides a control command once during steady state. After the signal Vcn is output, the output of the comparator COMP1 is set to a low level so that the steady-state control command signal is continuously output when the engine rotation speed decreases again and becomes lower than the start completion speed. It works to keep the state of (or zero level).

In the example shown in FIG. 5, the start completion speed setting signal Vns output from the start completion speed setting circuit 12 is output.
However, even if the instructed rotation speed of the internal combustion engine becomes high, the start control is maintained until the rotation speed becomes high accordingly. This is to make the engine start smoothly. However, the start completion speed setting signal Vns may be fixed to a constant value depending on the characteristics of the carburetor.

The steady state operation amount signal Vdn, the starting operation amount signal Vds, and the control command signals Vcs and Vcn are input to the operation amount signal selection circuit 14. The operation amount signal selection circuit 14 selects the operation amount signal at startup Vds when the start control command signal Vcs is input, and selects the operation amount signal Vdn at steady time when the control command signal Vcn at steady state is input. , And outputs the selected manipulated variable signal Vds or Vdn. The operation amount signal selection circuit 14 is a relay that is controlled by a control command signal and can output by switching between the operation amount signals Vds and Vdn.
It can be configured by a changeover switch circuit including an analog switch using a semiconductor switch.

The operation amount signal selected by the operation amount signal selection circuit 14 is input to the actuator drive circuit 8. The actuator drive circuit 8 is supplied with a battery 801 as a power source, a transistor circuit 802 including a power transistor Tr for controlling a drive current Id supplied from the battery to the actuator 3 and a diode D1, and an operation amount signal selection circuit 14. And a drive signal generation circuit 803 which gives a drive signal to the transistor circuit 802 in accordance with the manipulated variable signal. Next, the operation of the internal combustion engine controller of the above embodiment will be described. When the internal combustion engine 1 is started, the engine speed detected by the speed detection circuit 4 is equal to or lower than the start completion speed set by the start completion speed setting circuit 12, and therefore the control command signal generation circuit 13 starts the start control command. The signal is being output. At this time, the operation amount signal selection circuit 14 starts the operation amount signal Vds at the time of starting.
To input the signal Vds to the actuator drive circuit 8. The actuator drive circuit 8 supplies a drive current Id to the actuator 3 according to the operation amount signal Vds at the time of starting. The manipulated variable signal Vds reduces the deviation between the opening of the throttle valve 2 detected by the throttle opening detection circuit 9 and the set throttle opening at startup set by the startup throttle opening setting circuit 10 to zero. The actuator 3 operates the throttle valve so that the throttle opening degree matches the set opening degree at the time of starting. Therefore, the opening degree of the throttle valve 2 is maintained at the set throttle opening degree (for example, a half open state) at the time of starting until the rotation speed of the engine reaches the start completion speed.

When the rotation speed of the engine rises and once exceeds the start completion speed, the control command signal generation circuit 13 outputs a steady state control signal. At this time, the manipulated variable signal selection circuit 1
Reference numeral 4 selects the steady state operation amount signal Vdn and supplies the signal Vdn to the actuator drive circuit 8. The actuator drive circuit 8 supplies a drive current to the actuator 3 in accordance with the steady state operation amount signal Vdn. Since the manipulated variable signal Vdn changes so as to make the deviation between the rotation speed of the internal combustion engine and the instruction circuit speed zero, the actuator operates the throttle valve so that the rotation speed of the internal combustion engine matches the instruction rotation speed. Therefore, after the engine speed once exceeds the start completion speed, the opening degree of the throttle valve is controlled so as to keep the engine speed at the instructed speed.

Although the opening of the throttle valve is detected from the drive current of the actuator in the above embodiment, the opening of the throttle valve may be detected using a displacement amount detector such as a potentiometer or a differential transformer. You can

[0039]

As described above, according to the present invention, the steady-state manipulated variable calculation circuit, the startup manipulated variable calculation circuit, and the manipulated variable signal selection circuit are provided so that the engine speed is started when the internal combustion engine is started. Until the completion speed is reached, the throttle valve opening is controlled by the operation amount signal at startup so as to maintain the throttle opening set at startup. There is an advantage that the internal combustion engine can be kept easy to start. Also, after the internal combustion engine rotation speed exceeds the start completion speed and enters the steady operation state, the engine speed is controlled to be maintained at the command rotation speed by the steady state operation amount signal. Speed control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an exemplary embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a configuration of a throttle valve and an actuator used in an embodiment of the present invention.

3 is a diagram showing a relationship between an exciting current of an actuator and an opening degree of a throttle valve when the throttle valve and the actuator of FIG. 2 are used.

FIG. 4 is a circuit diagram showing a specific configuration example of a startup throttle opening setting circuit and a startup operation amount calculation circuit shown in FIG. 1.

5 is a circuit diagram showing a specific configuration example of a start completion speed setting circuit and a control command signal generating circuit shown in FIG.

FIG. 6 is a block diagram showing an overall configuration of a conventional example.

[Explanation of symbols]

 1 Internal Combustion Engine 2 Throttle Valve 3 Actuator 4 Speed Detection Circuit 5 Speed Indication Circuit 6 Speed Deviation Calculation Circuit 7 Constant Constant Operation Quantity Calculation Circuit 8 Actuator Drive Circuit 9 Throttle Opening Detection Circuit 10 Starting Throttle Opening Setting Circuit 11 Starting Operation Quantity calculation circuit 12 Completion speed setting circuit at startup 13 Control command signal generation circuit 14 Manipulation amount signal selection circuit

Claims (1)

[Claims] 1. An electric actuator that operates a throttle valve of an internal combustion engine, a speed detection circuit that detects a rotation speed of the internal combustion engine and outputs a speed detection signal, and an instruction rotation speed of the internal combustion engine is set. A speed instruction circuit that outputs an instruction speed signal; a speed deviation calculation circuit that calculates a deviation between the rotation speed of the internal combustion engine and the instruction rotation speed from the speed detection signal and the instruction speed signal and outputs a deviation signal; A steady state operation amount calculation circuit for calculating an operation amount of the actuator required to make the deviation between the rotation speed of the internal combustion engine and the instruction rotation speed zero from the deviation signal and outputting a steady state operation amount signal; A throttle opening detection circuit that detects the valve opening and outputs a throttle opening detection signal, and a start-up slot that corresponds to the set throttle opening when the internal combustion engine is started. A throttle opening setting circuit for starting, which outputs a tor opening setting signal, and a deviation between the throttle opening and the set throttle opening at starting are input using the starting throttle opening setting signal and the throttle opening detection signal as input. A manipulated variable calculating circuit for starting, which calculates the manipulated variable of the actuator required to make it zero and outputs a manipulated variable signal at starting, and a start, which outputs a start complete speed setting signal for setting the start complete speed of the internal combustion engine. Completion speed setting circuit, outputs the start control command signal until the rotation speed of the internal combustion engine reaches the start completion speed by inputting the speed detection signal and the start completion speed setting signal, and the rotation speed of the internal combustion engine once A control command signal generating circuit that outputs a control command signal at steady state after the start completion speed is exceeded, and the operation amount signal at start when the start control command signal is generated. And a manipulated variable signal selecting circuit for selecting the steady-state manipulated variable signal when the steady-state control command signal is being generated, and the manipulated variable signal selected by the manipulated variable signal selecting circuit. An internal combustion engine controller, comprising: an actuator drive circuit that supplies a drive current to the actuator.