JPS59136551A - Carburettor - Google Patents

Abstract

PURPOSE:To improve the starting charactristic as well as the accelerating characteristic of an engine by a method wherein a pump, driven by an electric actuator upon beginning of acceleration as well as starting of the engine which are sensed by the change of opening degree of a throttle valve, is operated to supply fuel. CONSTITUTION:When an ignition switch is put ON to start the engine, an initiating operation is effected to clear all of units in a system initially, thereafter, an initial value is set in the RAM of a computer 22. When a start switch is put ON under this condition, a control is shifted to the steps 101, 102, 103, a cooling water temperature is detected in the step 104, the increasing amount of fuel for starting, in accordance with the cooling water temperature, is set in the step 105, the pump is operated under repeating connection and disconnection in a solenoid from the step 106 to the step 107, then the control of the system is shifted from the steps 102, 103, 106 to the step 102 and the engine may be started smoothly under a condition that necessary assisting fuel is supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION In addition to supplying fuel from a main nozzle corresponding to the throttle valve opening and engine speed in a fuel supply system using a carburetor, the present invention provides an auxiliary supply to the intake passage during engine startup and acceleration. This relates to a carburetor that supplies fuel.

Conventionally, methods for supplying auxiliary fuel to a carburetor when starting or accelerating an engine include using a pump that is mechanically linked to the opening and closing of the throttle valve, and using a fixed venturi carburetor to replace the valve with a stepping motor. For mechanical pumps, there is a method to increase the amount of auxiliary fuel and suck it out from the main nozzle of the venturi by closing the choke valve and increasing the venturi negative pressure, but in the case of mechanical pumps, the amount of auxiliary fuel can be increased. In addition to being difficult to control, it is necessary to press the accelerator when starting at a low temperature, and when accelerating from a medium or high load range, the pump operates even though it is not necessary, and excess fuel is discharged. Fuel consumption gets worse. On the other hand, in the case of the choke valve drive system, it is necessary to use a stepping motor with strong driving force to quickly close the choke valve, which requires a large stepping motor, and it is not possible to obtain a sufficient amount of intake air at startup. Therefore, even when the check valve is fully closed, it is difficult to suck out fuel from the main nozzle, making it impossible to secure the necessary amount of auxiliary fuel, and as a result, there is a drawback that it is difficult to start the engine.

Therefore, when we investigated the amount of auxiliary fuel required during acceleration, we found that
■Fuel required to wet the wall upstream of the throttle valve
And, especially at low temperatures, the fuel flows through the intake pipe in liquid form! A correction fuel amount for the delay in twist supply due to being slower than the air flow can be classified into type 2a.

In this case, the amount of fuel in the above item (■) is constant regardless of the acceleration mode, and it is necessary to supply it as soon as possible after the start of acceleration, but it is not necessary for acceleration after the main system comes out. is related to temperature and acceleration mode, and it was found that after the start of acceleration, it is necessary to supply at a slower rate over time than in case (2) above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a carburetor which detects the amount of fuel by, for example, a change in the opening of a throttle valve and supplies the fuel by operating an electric actuator-driven pump at the start of acceleration and engine startup. It consists in being eliminated.

Next, the configuration of the first embodiment of the present invention will be explained with reference to the drawings.

An intake passage that communicates the air filter (not shown) with the cylinder 2 of the engine 1, in this case, from upstream to downstream of the intake passage 3, which has a sufficient intake passage area equivalent to the conventional two barrels to accommodate the amount of intake air at high output. a blow valve 5 driven by an electric actuator, in this case a stepping motor 4;
Fixed small and large bench lilies 6.7 and a throttle valve 8 that operates in conjunction with the accelerator pedal are provided, and the small bench lily 6 is provided with a throttle valve 8 that operates in conjunction with the accelerator pedal. A main nozzle 12 is formed which supplies fuel from the float chamber 9 from the main jet 10 to the intake passage B through the main fuel passage 11 by means of negative and positive venturis corresponding to the rotation speed, and an electric actuator, In this case, a pump 19 operated by the on/off operation of the electromagnetic solenoid 13, the reciprocating movement of the piston 16 in the cylinder 15 by the spring 14, and the action of the check valves 17 and 18 moves fuel from the foot chamber 9 into the fuel passage. 2
An auxiliary nozzle 21 is formed to supply air to the intake passage B through 0, and the stepping motor 4 of the valve 5 and the electromagnetic solenoid 13 of the pump 19 are:
2. In this case, a pressure switch 23 that senses the pressure in the intake passage 6, an Ibnira Chiron filter 24 that senses the engine speed, and a temperature sensor 25 that senses the engine coolant temperature.
and a throttle sensor 2 that detects the opening degree of the throttle valve 8.
It is controlled by a computer 22 which takes the output from 6 as an input signal.

Next, the operation of the vaporizer 27 configured as described above will be explained with reference to the chart 70 in FIG. 2 and the operation diagram in FIG. 6.

First, when the evening light switch is turned on in response to starting the engine, the system first performs an initialization operation to clear all devices, then restarts the computer 22.
When the starter is turned on in this state, the system shifts from 101° to 103, and the cooling water temperature is detected in step 104 when the starting increase amount of auxiliary fuel is not set. , After the starting amount increase corresponding to the cooling water temperature is set in step 105, the pump 19 is activated in steps 106 and 107, that is, the electromagnetic solenoid 1'5 repeats on and off operations, and the specified auxiliary fuel is With the amount dispensed, the system proceeds to step 102,1.
03, 10 (transfers from S to 102, and the engine 1 starts smoothly with the necessary auxiliary fuel supplied.

In this state, the system determines in step 102 that the system has been started, and moves from steps 108 and 109 to 110, and the engine speed and throttle sensor 26 output detected in steps 108 and 109 are outputs corresponding to engine acceleration, for example, If the IdM level in Figure 3A has not been reached, the system jumps to step 102, but if it is determined to be accelerated, the system jumps to step 111,
112° When the mode shifts from 113 to 114, the always-on electromagnetic solenoid 16 is turned off, and the piston 16 moves forward via the biasing force of the spring 14, causing the fuel in the cylinder 15 to be discharged into the intake passage 3 and onto the wall surface of the passage 6. In this state, the choke valve 5 closing mode corresponding to the cooling water temperature and the intake passage is calculated, and the stepping motor 4 adjusts the acceleration performance as shown in FIG. 3C, for example. The rich air-fuel mixture produced by closing the check valve 5 at an appropriate angle is supplied to the engine 1 without adhering to the wall of the intake passage 3. Fuel ratio control is performed accurately and the acceleration performance of the engine 1 is greatly improved.

Furthermore, both the closing speed and angle of the check valve 5 during acceleration are relatively small due to the fuel supply from the pump 19, making the stepping motor 4 for driving the check valve 5 small, lightweight, and inexpensive. In addition, by changing the opening degree of the check valve 5 to a small or large degree depending on whether the engine 1 is at low output or high output, the venturi negative pressure can be increased at low output and can be increased at high output. In this case, by ensuring a sufficient amount of intake air, combined with the auxiliary fuel supply, and by simplifying the structure, engine performance can be easily and significantly improved.

Next, FIG. 4 shows a second embodiment of the present invention. In this case, since the fuel discharge force of the pump 29 driven by the electromagnetic solenoid 28 can be designed to be sufficiently strong, the spring 31 of the check valve 60 is set sufficiently strong. Therefore, the configuration, operation, and effects are the same as those described above, except that the auxiliary fuel supply auxiliary nozzle 62 is provided near the throttle valve 64 downstream of the large bench lily 63. This is almost the same as the first embodiment.

Next, the effects of the present invention will be explained.

This R [is an electric actuator from upstream to downstream of the intake passage that communicates the air filter and the engine cylinder.
For example, a stepping motor 4-driven Chigok valve, a fixed venturi, and a throttle valve operated in conjunction with the accelerator pedal are provided, and the venturi has a venturi negative force corresponding to the opening degree of the throttle valve and the engine rotation speed. A main nozzle is provided that supplies fuel from a float chamber to the intake passage under pressure, and fuel from an electric actuator-driven pump that discharges fuel to the intake passage corresponds to an increase in engine output and when starting the engine is provided. An auxiliary nozzle is provided to supply the air, and the electric actuator of the check valve is controlled in accordance with the optimum air-fuel ratio determined by the opening degree of the throttle valve, the cooling water temperature, and the negative pressure in the intake passage when the engine output increases. The vaporizer is equipped with a control device, for example a computer 22.

As a result, the present invention has the advantage that the engine starting and acceleration performance can be significantly improved with a simple structure and with ease.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the first embodiment of the present invention, FIG. 2 is a 74-chart diagram showing the microcontrol of the computer 22, FIG. 6 is its operation diagram, and FIG. FIG. 2 is an explanatory diagram of a second embodiment. 1...Engine 2...Cylinder 3...
・Intake passage 4...Stepping motor 5...Choke valve 6...Venturi 8.
34...S E127 torque valve 9...Float chamber 12...Main nozzle 13.28...Electromagnetic solenoid 19.29...Pump 21.3
2... Auxiliary nozzle 27... Carburetor Applicant: Aisan Kogyo Co., Ltd. Agent: Hidehiko Ta, Patent Attorney

Claims (2)

[Claims] (1) From upstream to downstream of the intake passage that communicates the air filter with the engine cylinder, install a check valve driven by an electric actuator, a fixed venturi, and a throttle valve that operates in conjunction with the accelerator pedal. 70-)
A main nozzle for supplying fuel from the chamber to the intake passage is provided, and an auxiliary supply for supplying fuel to the intake passage from an electric actuator-driven pump that discharges fuel to the intake passage in response to an increase in engine output and at the time of starting. A control device is provided, which includes a nozzle, and controls the electric actuator of the four-way valve in accordance with the optimum air-fuel ratio determined by the opening degree of the throttle valve, the cooling water temperature, and the negative pressure in the intake passage when the engine output increases. vaporizer. (2) A patent characterized in that a stepping motor is used as an electric actuator for driving a check valve (3)
The vaporizer according to claim 1 or 2, characterized in that an electromagnetic solenoid is used as the electric actuator for driving the pump.