JPS6325346A - Throttle valve control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve response, by a method wherein, when a throttle valve opening is in an allowable range of a target value, by means of which a minimum fuel comsumption factor is obtained depending upon the number of revolutions, in response to the number of revolutions, a minimum fuel consumption factor responding to the number of revolutions is provided. CONSTITUTION:A control circuit 17 controls the opening of a throttle valve 12 with the aid of a pulse motor 15 based on detecting values from an accel working position sensor 7, a throttle value opening sensor 14, a crank angle sensor 18, a sensor 19 for an absolute pressure in an intake air pipe and the like. The control circuit 17 reads a target throttle valve opening, by which a minimum fuel consumption factor is provided depending upon the number of revolutions, from a data map to perform feedback control. However, when a deviation between an actual throttle valve opening and a target value is in a given range, correction is further made on a throttle valve opening so that a pressure in an intake air pipe is adjusted to a target value set according to the number of revolutions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a throttle valve control device for controlling the opening degree of a throttle valve of an internal combustion engine.

11. Known methods for improving the fuel efficiency of internal combustion engines include lean combustion, which makes the air-fuel ratio of the supplied air-fuel mixture leaner, swirl, which strengthens the gas flow within the combustion chamber, and improvement in the shape of the combustion chamber. However, both methods have a problem in that the structure is complicated and the cost is relatively high.

In order to solve this problem, it is conceivable to control the opening degree of the throttle valve. However, with conventional throttle valve control, for example, as disclosed in Japanese Patent Application Laid-Open No. 1984-1984, the opening degree of the throttle valve is simply determined according to the actuation position of the accelerator and the engine speed, so it is not possible to improve fuel efficiency. Ta.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a throttle valve control device for an internal combustion engine that has a simple configuration and can sufficiently improve fuel efficiency at low cost.

The throttle valve control device of the present invention sets a target throttle valve opening that provides a minimum fuel consumption rate in accordance with the detected engine speed, and sets a target throttle valve opening that provides a minimum fuel consumption rate in accordance with the detected engine speed. The pressure is set, and when the detected actual throttle valve opening is within the allowable range of the target throttle valve opening, the throttle valve is set to reduce the deviation between the actual intake pipe pressure and the set target intake pipe pressure. and when the actual throttle valve opening is outside the allowable range of the target throttle valve opening, the throttle valve is driven to reduce the deviation between the actual throttle valve opening and the target throttle valve opening. It is a feature.

Large-1-μ Embodiments of the present invention will be described below with reference to the drawings.

In the throttle valve control device for an on-vehicle internal combustion engine, which is an embodiment of the present invention shown in FIG. It is rotatable. A return spring 4 is provided at the other end of the bracket 2, and urges the accelerator pedal 1 toward the idle position. The shaft 3 is provided with an accelerator operating position sensor 7 consisting of a potentiometer, and the accelerator operating position sensor 7 outputs a voltage according to the operating position of the accelerator pedal 1, that is, the accelerator angle, which is the rotation angle from the idle position around the shaft 3. occurs.

On the other hand, the shaft 1 of the throttle valve 12 in the engine intake pipe 11
2a is provided with a throttle valve opening sensor 14 which is also a potentiometer, and the throttle valve opening sensor 14 is connected to the throttle valve 1.
Generates an output voltage according to the opening degree of 2. Also shaft 1
A rotating shaft of a pulse motor 15 is coupled to 2a.

The accelerator operation position sensor 7 , throttle valve opening sensor 14 , and pulse motor 15 are connected to a control circuit 17 . The control circuit 17 further includes the crankshaft of the engine 16 (
A crank angle sensor 18 generates a pulse at a specific crank angle according to the rotation of the engine (not shown), an absolute pressure sensor 19 generates an output according to the absolute pressure in the intake pipe 11, and fuel is injected and supplied to the engine 16. An injector 20 for this purpose is connected.

As shown in FIG. 2, the control circuit 17 includes a level conversion circuit 21 that converts the output levels of the accelerator operation position sensor 7, throttle valve opening sensor 14, and absolute pressure sensor 19, and each voltage signal that has passed through the level conversion circuit 21. a multiplexer 22 that selectively outputs one of the signals, an A/D converter 23 that converts the output voltage of the multiplexer 22 to A10, a waveform shaping circuit 24 that shapes the waveform of the output signal of the crank angle sensor 18, and a waveform shaping circuit. TDC output as a pulse from 24
The signal generation interval is determined by a clock pulse generation circuit (not shown).
a counter 25 that measures the number of clock pulses output from the drive circuit 26 that drives the pulse motor 15;
a, a drive circuit 26b that drives the injector 20,
CPtJ that performs digital operations according to the program
(central processing circuit) 27, a ROM 28 in which programs and data are written in advance, and a RAM 29.

Multiplexer 22, A/D converter 23, counter 25
, drive circuits 26a, 26b, CPU 27, ROM 28, and RAM 29 are connected to each other by a bus 30. Note that a clock pulse is supplied to the CPtJ 27 from a clock pulse generation circuit (not shown). The inferior CPU 27 constitutes the first and second setting means, and the C
The PU 27 and the drive circuit 26a constitute a drive means.

In this configuration, information on the accelerator angle θA CC% throttle valve opening θth and intake pipe absolute pressure PBA is alternatively sent from the A/D converter 23, and information on the engine speed Ne is sent from the counter 25 to the CPU 27. 30. The CPU 27 reads the ROM in synchronization with the clock pulse.
The above information is read according to the calculation program stored in 28, and the pulse motor 1 is
A pulse motor valve open drive command and a pulse motor valve close drive command for driving the pulse motor 15, or a pulse motor drive stop command for stopping the drive of the pulse motor 15 are sent to the drive circuit 2.
Occurs for 6a.

Next, the operation of the throttle valve control device according to the present invention will be explained with reference to the operation flow diagram of the CPU 27 shown in FIG.

The CPU 27 calculates the engine rotation speed Ne at every predetermined period.

The intake pipe absolute pressure PEA and the throttle valve opening θth are read (step 51), and a target throttle valve opening θthref corresponding to the read engine speed Ne is searched (step 52). The target throttle valve opening θthrer that provides the minimum fuel consumption rate according to the engine speed Ne with the characteristics shown in Fig. 4 is stored in the ROM 28 in advance as a θthrer data map. The target throttle valve opening θthrer is θthre
rSearch from the data map. In addition, the target intake pipe absolute pressure Pa A re according to the read engine speed Ne
f is searched from the PBA ref data map previously stored in the ROM 28 with characteristics as shown in FIG. 5 (step 53). Next, the read actual throttle valve opening degree θth
It is determined whether the absolute value of the deviation between the target throttle valve opening degree θthref and the target throttle valve opening degree θthref is smaller than a predetermined tolerance value θ1 (step 5
4) If lθth−θthrer l <θ, calculate the deviation ΔPEA between the target intake pipe absolute pressure Ps A r+J and the read intake pipe absolute pressure PBA.Step 5
5), opening correction amount Δ of the throttle valve 12 according to the deviation ΔPEA
θth is retrieved from the Δθth data map previously stored in the ROM 28 with the characteristics shown in FIG. 6 (step 56). On the other hand, if 1θth−θthr+J l≧θ1, the actual throttle valve opening θ[h to the target throttle valve opening θth
Let the deviation after subtracting rer be the opening correction amount Δθth (
Step 57). Once the opening correction amount Δθth is determined in this manner, the read throttle valve opening θ(h) is added to the opening correction amount Δθth to calculate the control opening θout (step 58).

Then, the read throttle valve opening θth is the control opening θou
It is determined whether it is equal to t (step 59).

If θth-θout, a pulse motor drive stop command is issued to the drive circuit 26a (step 60). θ
If th≠θout, the throttle valve opening θth is the control opening θ
Determine whether it is greater than out (step 61)
. If θth>θout, a pulse motor valve closing drive command is generated to the drive circuit 26a to drive the throttle valve in the valve closing direction (step 62); if θth>θout, that is, if θth minus θout, A pulse motor valve opening driving command is generated to the driving circuit 26a to drive the throttle valve in the opening direction (step 63).

The drive circuit 26a drives the throttle valve 12 in the opening direction by rotating the pulse motor 15 forward in response to the pulse motor valve opening drive command, and rotates the pulse motor 15 in the reverse direction in response to the pulse motor valve closing drive command. Throttle valve 12
is driven in the valve closing direction. Further, in response to the pulse motor drive stop command, the rotation of the pulse motor 15 is stopped to maintain the current throttle valve opening degree. By doing this, the throttle valve opening degree θth is made to follow the control opening degree θout.

That is, if 1θth-θthre4 l≧θ1, then
The actual throttle valve opening θth is far away from the target throttle valve opening θthref at which the minimum fuel consumption rate is obtained, and therefore the intake pipe absolute pressure PBA is changed to the target intake pipe absolute pressure Pa.
In order to make it equal to A ref, the absolute pressure in the intake pipe PB
Since it is necessary to control the throttle valve in a cycle slower than the time required to change A, the response is limited, so the deviation θt is set so that the throttle valve rapidly approaches the target throttle valve opening θthref.
The throttle valve is driven by setting h-θthref as the opening correction amount Δθth. Also, 1θ[h−θthrer l <
If θ1, the actual throttle valve opening θth is within the tolerance range of the target throttle valve opening θthref that provides the minimum fuel consumption rate, so the intake pipe absolute pressure PBA is made equal to the target intake pipe absolute pressure PsAref. Performs throttle valve control.

This is because even if the throttle valve is controlled in a slow cycle, the ability to follow the target intake pipe absolute pressure P8^ref is good.

In the embodiment of the present invention described above, the opening correction amount Δθ[h is calculated using the Δθth data map, but a predetermined calculation formula, for example, Δθth=k1・ΔPB
It may be calculated using A (kl is a constant).

Furthermore, in the embodiment of the present invention described above, the CPU 27
The drive circuit 26a generates pulses to the pulse motor 15 at a predetermined speed in response to a pulse motor valve opening drive command or valve closing drive command from The CPU 27 generates a pulse motor valve opening drive command or valve closing drive command representing the number of pulses corresponding to the difference from the degree θout to the drive circuit 26a, and the drive circuit 26a sends drive pulses to the pulse motor 15 by the number of pulses. It may also be supplied.

As described above, in the internal combustion engine throttle valve control device of the present invention, when the actual throttle valve opening is within the allowable range of the target throttle valve opening that provides the minimum fuel consumption rate, the actual throttle valve opening is The throttle valve is driven to reduce the deviation between the intake pipe internal pressure and the target intake pipe internal pressure that provides the set minimum fuel consumption rate, and when the deviation is outside the allowable range of the target throttle valve opening, the actual throttle valve opening is Since the throttle valve is driven so as to reduce the deviation from the target throttle valve opening, fuel efficiency can be improved at low cost, and delays in control a can be prevented and responsiveness can be improved.

Further, the throttle valve control device of the present invention is suitable for use in conjunction with a CVT (automatic transmission) device or the like that controls the engine speed according to the accelerator operating position.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a specific configuration of a control circuit in the device shown in FIG. 1, FIG. 3 is a flow diagram showing the operation of the CPU, and FIG. 4 to 6 are diagrams showing the characteristics of data maps stored in advance in the ROM. Explanation of symbols of main parts 1...Accelerator pedal 7...Accelerator operation position sensor 11...
・Intake pipe 12... Throttle valve 14... Throttle valve opening sensor 15... Pulse motor 17... Control circuit

Claims (1)

[Claims] A throttle valve control device for controlling the opening degree of a throttle valve disposed in an intake system of an internal combustion engine, the device comprising: an engine rotation speed detection means; a pressure detection means for detecting an intake pipe pressure downstream of the throttle valve; Throttle valve opening degree detection means for detecting the opening degree of the throttle valve, and a first throttle valve opening degree that sets a target throttle valve opening degree that provides a minimum fuel consumption rate in response to the engine rotation speed detected by the engine rotation speed detection means. a second setting means for setting a target intake pipe internal pressure at which a minimum fuel consumption rate is obtained corresponding to the detected engine speed; and a second setting means for setting a target intake pipe internal pressure corresponding to the detected engine speed; When the throttle valve opening is within the allowable range of the target throttle valve opening, the throttle valve is driven to reduce the deviation between the actual intake pipe internal pressure and the set target intake pipe internal pressure, and the throttle valve is adjusted to the actual throttle valve opening. the throttle valve opening is outside the allowable range of the target throttle valve opening, driving means for driving the throttle valve so as to reduce the deviation between the actual throttle valve opening and the target throttle valve opening. Throttle valve control device.