JPS62298645A - Automatic control in carburetor - Google Patents

Abstract

PURPOSE:To increase operational reliability of a step motor for driving a throttle valve, by controlling said motor with operating speed corresponding to set sensitivity constants of idle adjustment and of governor adjustment, and putting the throttle valve freely workably in closing direction when an acceleration pedal is in returning operation. CONSTITUTION:In making governing controlling a throttle valve 2 with a step motor SM4, at first, initial setting control of indexing original point of SM4 is made by a valve opening sensitive switch 7, then overrun check is made in ECU3 from the output of a rotation sensor 12m and a valve opening sensor 11. When any overrun is present, ignition timing is controlled by an engine stop circuit 13, and when the operation is normal, it is judged whether the operation is in an idle control range or a governor control range to calculate the speed of ST4 in the driving direction throttle valve control speed corresponding to the set sensitivity constant of each control range. When an acceleration pedal is returned, an SM output shaft 41 is connected to a valve shaft 5 with a universal joint 6 freely movable in the valve close direction, thus to actuate the throttle valve 2 in closing direction by a return spring.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an automatic control method for a carburetor for an internal combustion engine having a speed regulating control function.

[Conventional Techniques] Conventionally, it has been known that as a method of controlling the engine rotation, the throttle valve opening of the carburetor is adjusted by operating an actuator with a controller.
As shown in the figure, the throttle of the carburetor 1 is electrically operated remotely via an electronic controller 3 and a step motor 4 as an actuator. And the electronic controller 3 has a speed regulating control function,
The step motor output shaft and the carburetor valve shaft of these devices were connected by a universal joint 6.

[Problem that the invention seeks to solve]

However, such a traditional system? In the ffU system, the valve shaft of the carburetor and the output shaft of the step motor are connected by a universal joint, and the throttle operation of the carburetor is all controlled by electronic control. When a failure occurs, the valve shaft of the carburetor cannot be operated in the closing direction, which causes the internal combustion engine to overrun or become impossible to operate, making it impossible to ensure safety.

The present invention aims to eliminate these conventional drawbacks. Even if the electronic control system fails and the step motor stops, when the accelerator pedal is released, the throttle valve closes to prevent the internal combustion engine from overrunning. The objective is to provide a highly reliable control method that develops the speed control function, maintains safety in driving control, and greatly improves operability.

[Means for Solving the Problems] The present invention provides a first method for determining the origin of the actuator when controlling the throttle valve of the carburetor at 81!1 speed with a driving actuator. After setting the IJI, the engine rotation sensor and throttle valve opening sensor input engine rotation and throttle angle data into the electronic control unit to check for overrun, and if the overrun occurs, ignition control is performed to stop the engine accordingly. During normal operation, it determines the idle or governor control range, calculates the speed in the driving direction of the actuator at the throttle valve operation speed corresponding to the set sensitivity constant of each control range, and controls the speed by inputting and outputting the motor pulse. In addition, this automatic control method for a carburetor is characterized in that when the accelerator pedal is manually released, drive transmission between the throttle valve and the actuator is cut off and the throttle valve is operated in the closing direction.

Another feature of the present invention is that when the throttle valve of the carburetor is controlled by the driving actuator, the no-load idling position is used as the initial setting position for indexing the origin of the actuator, and the initial throttle distance is adjusted. After shifting the position from the above-mentioned no-load fitting position, an overrun check is performed by inputting engine rotation and throttle angle data to the electronic control unit using the engine rotation sensor and throttle valve opening sensor, respectively. Accordingly, the ignition control is performed to stop the engine, and when it is normal, the idle or governor control range is determined, and the speed in the drive direction of the actuator is calculated at the throttle valve operation speed corresponding to the setting variable constant of each control range. , a carburetor which outputs motor pulses to control the speed, and when the accelerator pedal is manually released, drive transmission between the throttle valve and the actuator is cut off and the throttle valve is operated in the closing direction. This is an automatic control method.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 to 5. The opening and closing operations of the throttle valve 2 of the carburetor 1 are performed by an electronic control unit (hereinafter referred to as ECU) 3 and by a step motor 4 as an actuator. The motor output shaft 4I and the valve shaft 5
is connected by a universal joint 6 and fixed to the valve shaft 5. A signal is transmitted to the ECU 3 by the valve opening detection switch 7 which is pressed and operated, and the step motor 4 is set to the origin, and a slip joint mechanism 8 is attached to the valve shaft 5 at the other end.
and a throttle lever 9, which is connected to a valve opening sensor 11 via a universal joint 10.
The output signal is set so as to enter the ECU 3.

That is, in order to detect the input angle of the throttle, the carburetor valve opening degree by the throttle lever is input as a voltage value to the ECU 3 via an A/D converter (not shown). A rotation signal from the engine rotation sensor 12 is introduced into the ECU 3, and the engine rotation signal is calculated with the valve opening signal.
It is designed to control 3.

The step motor 4 rotates forward and backward by a fixed angle in response to the output signal of the transistor of the ECLI 3. An operating lever 14 is pivoted on the output shaft 41 of the step motor 4, and the lever is pivoted on the valve shaft 5. 15 so as to be able to come into contact with and separate from it, and to be able to operate by contacting only one side, thereby forming a universal joint 6.

The throttle lever 9 pivotally supported on the valve shaft 5 is slow/
It connects the torque wire 16 and is rotatably provided on the valve shaft 5,
A coiled spring 19 is set between the throttle lever 9 and the 7" rate plate 18 fixed to the end of the valve shaft with the collar 17 in between, so as to apply force in the opening direction of the throttle valve 2. This constitutes a slip joint mechanism 8.

The plate with lever 18 is abutment part 9 which is a part of the slot lever 9. The valve opening is limited so that it does not open any further than that. A return spring 20 is attached to the throttle lever 9 and is tensioned in the throttle closing direction.

It goes without saying that the return spring 20 is stronger than the spring 19. Furthermore, the tip end of the abutment part 91 of the throttle lever 9 is inserted into the forked part of the valve opening sensor 11 to form a universal joint 1O. The electronic control unit 3 is electrically connected to the valve opening detection switch 7, the valve opening sensor 11, the engine rotation sensor 12, the engine stop circuit 13, and the step motor 4.

In this case, the ECU 3 receives a rotational speed signal of the internal combustion engine, a signal of the valve opening of the carburetor 1, and a signal of a predetermined valve opening from the valve opening detection switch 7, and calculates the rotation to a predetermined rotation. The step motor 4 rotates the carburetor valve shaft 5 in the closing direction, and when the operating lever 14 moves in the escape direction when it is in the opening direction, the throttle valve 2 is operated in the opening direction by the biasing force of the coil spring 19. Perform speed regulating control.

That is, as shown in the flowchart of the second circle, when controlling the throttle valve 2 of the carburetor 1 with the driving step motor 4, first, the initial setting control of the origin index of the step motor 4 is performed using the valve opening detection switch 7. After that, the engine rotation sensor 12 and the valve opening sensor 11 of the throttle valve 2 input the engine rotation and throttle valve data to the electronic control unit 3 respectively to check for overrun, and when the overrun occurs, the engine stop circuit 13 Control the ignition with
In addition, under normal conditions, after fail-safe control that guides the sensor to the safe side in the event of an assumed failure, the idle or governor control range is determined, and the throttle valve operation speed corresponding to the set sensitivity constant of each control range is used. step motor 4
It calculates the speed in the driving direction of the motor and outputs motor pulses to control the speed. When the throttle lever 9 and the lever plate 1 are working together to operate the throttle valve 2, when the throttle lever 9 is fully opened, the operation opening of the throttle lever 9 (valve opening sensor 11) is detected.
Is the opening controlled by step motor 4 regardless of ? ff1l
is performed, and the valve opening degree is controlled in a manner that suppresses the opening force of the coil spring 19, and the speed is regulated by the procurement valve opening degree.

That is, as shown in Figures 3 to 5, the throttle valve 2 has a structure in which a force is constantly applied to the throttle valve 2 by the spring 19 to rotate it in the opening direction. 9 is returned, the operating lever 14 of the step motor 4 does not act on the lever 15 because it has a one-sided supporting structure, and the lever plate 18 moves to the abutting part 9 of the throttle lever 9. It comes into contact with the throttle lever 9 and is integrated with the throttle lever 9, so that it can be reliably operated in the closing direction. Therefore, even if the electronic control system malfunctions or the step motor is inoperable, the valve will close when the accelerator pedal is released, increasing safety. Next, the means for setting the reference point for the initial setting operation will be explained in detail. The valve opening sensing switch 7 is adjusted and fixed at the idling position when the throttle valve is fully closed.

Next, the tip of the throttle opening adjustment TAS) 31 is in contact with the abutment part 9□ of the throttle lever 9, so this TAS 31 allows the adjustment position to be adjusted by slightly shifting the initial throttle opening m adjustment position from the idling position. Set. Therefore, there is an angular deviation between the two.

In the figure, reference numeral 21 denotes an acceleration pump arm connected to the throttle lever 9 by a connecting rod 22. Reference numeral 23 denotes a starting lever for interlocking the choke system, and is provided on the valve shaft via a guide. 24 is a washer, 25 is an oil-less metal, 26 is a fixing screw, 27 is a groove, 28 is a throttle lever guide, and 29 is a bearing portion.

Note that the engine rotation sensor 12 used for detecting the engine rotation speed may be one that outputs an excitation pulse from a ring gear to a counter.

〔Effect of the invention〕

The present invention calculates the speed in the driving direction of the step motor so as to control the step motor at a throttle valve operation speed corresponding to the set sensitivity constant of idle control and governor control, and sends a motor pulse output to the step motor to perform speed governor control. When the accelerator pedal is artificially released, the throttle valve is cut off from drive transmission with the step motor and operates in the closing direction, so even if a failure occurs in the electronic control system that controls engine rotation, the Since the valve acts in the closing direction, it has the effect of preventing engine overrun and ensuring safe operation control, and also allows for easy and reliable control of the carburetor. It is. In addition, since there is an angular deviation between the idling position, that is, the step motor origin setting position and the initial throttle opening adjustment position, if a slight load is applied during the fitting state, the engine speed will drop to the idling speed. The throttle valve is at the idling position (the position where the valve opening is 0) while the throttle motor runs away in the direction of opening the valve. Since the IJI throttle opening is adjusted to 5 degrees, it is possible to prevent the engine from stalling.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the system, Figure 2 is a flowchart of the control program, Figure 3 is a partial sectional view of the carburetor, Figure 4 is a side view of the carburetor in use, and Figure 5 is a slope view of the separated state. , FIG. 6 is a system explanatory diagram of a conventional example. 1... Carburetor, 2... Throttle valve, 3... Electronic control unit, 4... Step motor, 41
... Ste, Pumoke output shaft, 5... Valve shaft, 6.10
...Universal joint, 7...Valve opening detection switch, 8...
・Slip joint mechanism, 9... Throttle lever, 11
... Valve opening sensor, 12... Engine rotation sensor,
13... Engine stop circuit, 14... Operating lever, 15
... Lever, 15, ... Stopper lever, 16...
・Throttle wire, 17... Collar, 18... Plate with lever, 19... Spring, 20... Return spring. Patent Applicant Nissan Koki Co., Ltd. Representative Patent Attorney Yakushi Neji Representative Patent Attorney Yori 1) Takatsugu Department Representative Patent Attorney
Masayuki Takagi Figure 2

Claims (1)

[Claims] 1. When controlling the throttle valve of the carburetor with a driving actuator, after initial setting of the origin index of the actuator, the engine rotation sensor and the throttle valve opening sensor control the engine rotation. Each throttle angle data is input to the electronic control unit to check for overrun, and when the overrun occurs, ignition control is performed to stop the engine accordingly, and when normal, the idle or governor control range is determined, and each control range is The speed in the driving direction of the actuator is calculated using the throttle valve operation speed corresponding to the set sensitivity constant, and the motor pulse is output to perform speed control control, and when the accelerator pedal is artificially released, the drive transmission between the throttle valve and the actuator is interrupted. An automatic control method for a carburetor, characterized in that the throttle valve is operated in the closing direction when the throttle valve is shut off. 2. The throttle valve opening sensor converts the accelerator input opening into a voltage and inputs it to an electronic control unit, and the output signal from the electronic control unit drives an actuator to manipulate the position of the throttle valve. A control method according to claim 1. 3. The control method according to claim 1 or 2, wherein the governor control operates the throttle valve by setting the throttle input opening as the maximum control opening. 4. A patent that maintains a connected state in which the drive transmission of the actuator acts in one direction, and that when the accelerator pedal is returned to the valve closing direction, the throttle valve is automatically rotated in the closing direction. A control method according to any one of claims 1 to 3. 5. When regulating the throttle valve of the carburetor with the drive actuator, the no-load idling position is set as the initial setting position for indexing the origin of the actuator, and the initial throttle opening adjustment position is set from the no-load idling position. After shifting, the engine rotation sensor and throttle valve opening sensor input engine rotation and throttle angle data to the electronic control unit to check for overrun, and if overrun occurs, ignition control to stop the engine is performed accordingly. In addition, during normal operation, it determines the idle or governor control range, calculates the speed in the driving direction of the actuator at the throttle valve operation speed corresponding to the set sensitivity constant of each control range, outputs motor pulses, and performs governor control. An automatic control method for a carburetor, characterized in that when the accelerator pedal is artificially released, drive transmission between the throttle valve and the actuator is cut off and the throttle valve is operated in the closing direction.