JPH0617654B2 - Throttle valve control device for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a throttle valve control device for electrically driving and controlling a throttle valve of an internal combustion engine.

(Prior Art) Conventionally, a throttle valve control device for an internal combustion engine transmits the operation of an accelerator pedal to a throttle lever by a throttle cable or a link mechanism, and directly controls a throttle valve connected to the throttle lever. In the case of this control, there is a drawback that a throttle valve opening sensor for detecting the opening of the throttle valve must be separately provided as a control element for air-fuel ratio control and exhaust gas control during engine operation.

Also, when the mechanical connection between the accelerator pedal and the throttle valve is disconnected, and the throttle valve drive motor is controlled by the output from the depression amount detection potentiometer by the accelerator pedal operation, the same as the above control.
As a control element for air-fuel ratio control and exhaust gas control, there is a drawback that a throttle valve opening sensor for detecting the throttle valve opening and for synchronizing opening / closing of the throttle valve with respect to the accelerator pedal must be mounted separately.

(Object of the Invention) When the throttle valve is controlled by the motor drive by the output from the potentiometer corresponding to the depression amount of the accelerator pedal, for example, the motor is pulsed by the output from the counter corresponding to the depression amount of the accelerator pedal. It is an object to provide a throttle valve control device for an internal combustion engine to be controlled, and to easily and highly accurately control the opening of a throttle valve without using a throttle valve opening sensor by simplifying the structure.

(Structure of the Invention) As shown in FIG. 1, the present invention relates to a step motor 2 for controlling the opening / closing of a throttle valve 1 of an internal combustion engine, and a torque transmission device for transmitting a rotational torque of the step motor 2 to the throttle valve 1. 3 and a throttle back spring 4 for urging the throttle valve 1 in the fully closing direction
And an accelerator sensor 6 for generating an output signal corresponding to the depression amount of the accelerator pedal 5, and a pulse is output to the step motor 2 according to the output signal of the accelerator sensor 6 to drive the step motor 2 and An electric control circuit 7 incorporating a pulse counter for counting the number of output pulses and detecting the position of the throttle valve 1.
And a reference opening detection switch 8 for detecting a constant opening as a reference of the throttle valve 1 and setting the pulse counter to 0 by the detection signal,
The throttle valve control device for an internal combustion engine is characterized in that the count reference position of the pulse counter is set to a position when the reference opening detection switch 8 changes from at least one of ON / OFF to the other.

(Embodiment of the Invention) Next, a configuration of an embodiment of the present invention will be described with reference to FIGS.

In FIG. 2, a throttle valve 11 is fixed to a throttle shaft 12, and the opening area of the carburetor intake passage is adjusted by rotating the throttle shaft 12 on a bearing provided in the carburetor 13.

The throttle back spring 14 has a carburetor 13 at one end.
Then, the other end is engaged with the lever 15 fixed to the throttle shaft 12 to operate the throttle valve 11 in the closing direction.

The step motor 16 is attached to the carburetor 13 via the gear housing 17, and
The throttle shaft 12 is rotated via the reduction gear train of the torque transmission device formed by the internal gears 18 to 21.

Reference numeral 22 is an accelerator sensor for generating an output signal corresponding to the amount of depression of the accelerator pedal 23, 24 is an ignition switch for connecting the battery 25 and the electric control circuit 26, and 27 is a throttle for detecting the reference opening of the throttle valve 11. Indicates a switch.

The structure and mounting of the throttle switch 27 will be described with reference to FIG.

In FIG. 3, the projection 28 of the large gear 18 fixed to the throttle shaft 12 and the tip of the rod 29 of the throttle switch 27 are configured to engage with each other, and the rod 29 is a small-diameter cylindrical hole opened inside the screw 30. Is inserted so as to be capable of reciprocating, and a plate 31 serving as an electric contact member is fixed to the tip end opposite to the tip engaging with the protrusion 28, and a relief spring 32 serving as a conductive part is fixed to the plate 31. An electric wire connected to the plate terminal 33, which is seated between the plate terminals 33 serving as electrodes and configured to apply the compressive force of the relief spring 32 to the plate 31 to close the electric contact between the screw 30 and the plate terminal 33. 34 is connected to the electric control circuit 26.

The cover 35, which serves as an electrically insulating member, is integrated with the head of the screw 30 by caulking the screw 30 into the head of the screw 30.

The outer peripheral part of the screw 30 has a hexagonal shape, and the outer peripheral part having a small diameter has a screw structure so that it can be mounted in a screwed state on the gear housing 17, and the rod 29 and the large gear 18 projection 28 are engaged. The adjusting spring 36 for adjusting the opening / closing position of the electric contact of the plate 31 is attached so as to urge between the head of the screw 30 and the gear housing 17.

FIG. 4 shows a block diagram of the electric control circuit 26. In FIG. 4, 37 is an AD converter for converting an analog output signal from the accelerator sensor 22 into a digital signal,
38 is an I / O port of a microcomputer CPU described later, 39 is a motor drive circuit for outputting a drive step current to the step motor 16, and 40 is an electric control circuit 26.
The power supply circuit of the CPU is the throttle valve 11 of the internal combustion engine.
Which is a central processing unit for controlling the CPU and also has a pulse counter function for counting and storing the number of steps of the drive step signal output to the step motor 16, and ROM indicates a memory circuit having a control program built-in. .

Next, the operation of the embodiment of the present invention will be described with reference to the flow charts of FIGS.

FIG. 5 shows an input check routine of the throttle switch 27 for detecting the reference opening degree of the throttle valve 11. In step 101, the throttle switch 27 is checked.
O when the reference opening of the throttle valve 11 is detected by
At the time of switching from N to OFF and from OFF to ON, when the throttle switch 27 outputs a switching signal from OFF to ON to the microcomputer CPU, step 1
At 02, the microcomputer CPU performs arithmetic processing, sets a flag "1", and sets the pulse counter to 0.

The throttle switch 27 is turned on in step 103.
Signal to switch from off to microcomputer CPU
Then, in step 104, the microcomputer CPU performs arithmetic processing to set a flag "0" and sets the pulse counter to zero.

The pulse counter in the microcomputer CPU is set to 0 regardless of the ON / OFF direction of the switching signal of the throttle switch 27, and the control operation direction from the reference opening position of the throttle valve 11 is detected in a flag state.

FIG. 6 is a flow chart showing the control program of this embodiment. In step 105, the microcomputer CPU has a flag "0" and a pulse counter value N.
When the internal combustion engine is set to X, the accelerator pedal 23 is depressed in step 106, and an output signal corresponding to the operation of the accelerator pedal 23 is output by the accelerator sensor 22 to the electric control circuit 26. When input to the microcomputer CPU via the D converter 37 and the I / O port 38, an output step signal, which is compared with the driving amount of the step motor 16 in accordance with the output signal of the accelerator sensor 22 in step 107, together with the rotation direction signal. After being output to the motor drive circuit 39 through the I / O port 38 and converted into a drive current,
Output to the step motor 16 and throttle valve 11
Control the opening of.

In step 108, the output step signal corresponding to the drive amount of the step motor 16 output from the microcomputer CPU is subtracted and counted by the pulse counter for each output step as a subtraction value from the pulse counter value NX during idling of the internal combustion engine.

In step 109, the output signal of the throttle switch 27 is O while the drive current is being output to the step motor 16.
When the throttle valve 11 reference opening signal is input to the microcomputer CPU by switching from FF to ON, the microcomputer CPU sets a flag "1" in step 110, sets the pulse counter to 0, and sets the reference in step 111. To complete.

By this initialization processing, the synchronism of the throttle valve opening and the pulse counter is secured, and when the step signal is continuously output to the step motor 16 in step 112, the pulse counter is set to 0 in step 113 for each output step signal. Is counted as the addition value from the above, and the predetermined control is completed at the time point when the number of pulses corresponding to the preset accelerator opening sensor signal and the pulse counter value NY match in step 114.

(Advantages of the Invention) In the present invention, in the open loop control of the throttle valve opening by the step motor, the pulse count of the step motor corresponding to the throttle valve opening is set to "0", that is, the count reference position of the counter is set. A state where a throttle switch provided in the stroke range of the throttle valve is set to a position when it changes from at least one of ON / OFF to the other, thereby simplifying and simplifying the entire configuration and control of the open loop control of the throttle valve. In addition, there is an effect that sufficient control accuracy and durability can be ensured, and the occurrence of cumulative error of counter miscount can be prevented to obtain higher control accuracy.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram clearly showing the configuration of the present invention, FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is a partial explanatory diagram of the present embodiment, and FIG. 4 is an electrical diagram of the present embodiment. Block diagram of control circuit,
FIG. 5 is an initial check flowchart of this embodiment, and FIG. 6 is a control flowchart of this embodiment. 1: Throttle valve 2: Step motor 3: Torque transmission device 4: Throttle back spring 5: Accelerator pedal 6: Accelerator sensor 7: Electric control circuit 8: Reference opening detection switch

Claims (1)

[Claims] 1. A step motor for controlling the opening / closing of a throttle valve of an internal combustion engine, and a torque transmission device for transmitting the rotational torque of the step motor to the throttle valve.
A throttle back spring for urging the throttle valve in the fully closed direction, an accelerator sensor for generating an output signal corresponding to the depression amount of the accelerator pedal, and a pulse output to the step motor according to the output signal of the accelerator sensor. Then, the stepper motor is driven and an electric control circuit having a built-in pulse counter for detecting the position of the throttle valve by counting the number of output pulses and a fixed opening from the fully closed position of the throttle valve are opened. A reference opening detection switch for detecting a predetermined opening and setting the pulse counter to 0 according to the detection signal, and setting the count reference position of the pulse counter to one of ON and OFF of the reference opening detection switch. Of the internal combustion engine, characterized in that it is set to the position when it changes from one to the other Lube controller.