JPH0137182Y2 - - Google Patents

Description

[Detailed description of the invention] Conventional type carburetors, more specifically, carburetors without electronic control means, have problems such as starting the engine,
In order to respond to operating conditions such as warm-up, acceleration, and output operation, in addition to the main fuel system and low-speed fuel system, we are equipped with means such as a starter carburetor, choke valve, acceleration pump, and enrichment mechanism. In other words, it has a bypass port that requires high machining accuracy and has poor productivity, and this ensures the connection between the main fuel system and the low-speed fuel system. Furthermore, selection of this bypass port has the problem of requiring time and effort to set up the carburetor from both the viewpoints of fuel efficiency and ensuring connection. The present invention simplifies the structure of the carburetor by eliminating the above-mentioned means added to the main fuel system and the low-speed fuel system, and also improves the productivity of the carburetor by removing the unproductive bypass port from the low-speed fuel system. On the other hand, by electronically controlling the rotation speed of the rotary fuel pump, appropriate fuel flow rate control is performed, and the air-fuel ratio of the mixture is controlled in a closed loop to a ternary point using a sensor for oxygen concentration in the exhaust gas. An object of the present invention is to provide an electronically controlled carburetor that can be easily set up.

The electronically controlled vaporizer of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows an embodiment in which the electronically controlled vaporizer of the present invention is applied to a down draft open bench lily vaporizer, and FIG. 2 shows a control system block diagram of the electronically controlled vaporizer of the present invention. In both figures, reference numeral 1 is an electronically controlled carburetor of the present invention, 2 is a main intake passage, 3 is a bench lily, 4 is a small bench lily, and 5 is a float chamber. 6 is a main jet, 7 is a main air jet, 8 is a bleed pipe, and 9 is a main nozzle, and each part of 6 to 9 constitutes a main fuel system. 10 is a pilot jet, 11 is a pilot air jet, 12 is a pilot outlet, and 13 is a pilot screw for adjusting the opening area of the pilot outlet. 10
A low-speed fuel system is comprised of 13 to 13 parts. 14 is a throttle valve, and 15 is a rotary fuel pump in which the fuel flow rate is controlled by rotational speed, and is driven directly or at reduced speed by, for example, a stepping motor. 1
Reference numeral 6 denotes a control circuit based on a microprocessor unit, which controls the rotation speed of the fuel flow rate of the rotary fuel pump 15 driven by the stepping motor. 17 is a fuel passage that communicates the suction side of the rotary fuel pump 15 with the float chamber 5; one end of 18 is open to the upstream side of the throttle valve 14 (in the figure, the upstream side of the small bench lily); This is a fuel nozzle connected to the discharge side of the rotary fuel pump 15. By arranging an ultrasonic atomizer as shown in Fig. 5 at the opening of the fuel nozzle 18, it is possible to improve combustion efficiency and responsiveness, and since the flow rate is small with only supplementary fuel, less than 20 watts is sufficient. be. In the figure, 26 is a Languevent type vibrator, 27 is a high frequency oscillator, and 28 is a vibrator horn.

In the electronically controlled carburetor having the above configuration, the control circuit 16 controls the throttle valve opening signal 19, the engine intake negative pressure, the rotational speed, the engine temperature, the oxygen concentration in the exhaust gas (the intake air The fuel is discharged from the main fuel nozzle 9 and the pilot outlet 12 by inputting various operating parameter signals 20 such as mixture ratio), atmospheric conditions (atmospheric pressure, intake air temperature, intake air humidity) signal 21, and starting motor on/off signal 22. The difference between the fuel flow rate required by the engine and the fuel flow rate required by the engine is calculated by the table lookup method, and the output signal is sent to the rotary fuel pump 1.
The signal is output to, for example, a stepping motor that drives the motor. To add a little more explanation to each of the above input signals, the engine speed signal is calculated from the ignition signal, and the engine temperature signal is obtained by measuring the temperature of the cylinder head, cooling water, lubricating oil, or spark hydrant seat using a thermistor. obtained by doing. Further, the throttle valve opening signal 19 is obtained from a potentiometer arranged on the throttle valve shaft. However, the means for generating the input signal is omitted in the drawing.

The rotary fuel pump 15 described above supplies fuel to ensure the connection between the main fuel system and the low-speed fuel system in place of the bypass port of a conventional carburetor that does not have electronic control elements, and also at the time of starting (cranking). ), it is possible to achieve the function of increasing the amount during starting and warm-up operation instead of the starter carburetor or the choke valve, increasing the amount of accelerating amount during acceleration instead of the accelerator pump, and increasing the amount of amount during output operation instead of the power nozzle. 23 is an accelerator pedal of the vehicle, and 24 is an engine. In the above description, the term "increase" means an increase in the amount of fuel.
Although the idling speed control device (ISC) is not mentioned in the drawings or the above description, the idling speed control device is arranged on the throttle valve lever, and the control circuit 16 is provided with an idle up request signal (electrical load, cooler compressor). An idle up function can also be provided by inputting the tuft on/off signal. In order to control the mixture ratio to a three-way point in a closed loop using the oxygen concentration signal in the exhaust gas, the fuel flow rates of the main fuel system and the low-speed fuel system are adjusted to the lean tendency, and the insufficient flow rate is compensated for by the rotary fuel pump 15. It is necessary to make up for it. FIG. 3 shows a longitudinal section of an example of the rotary fuel pump 15, in which 15-1 is a rotor, and 15-2 is a rotor 15.
-1 is a vane that slides in and out of the groove in the radial direction. When the rotor 15-1 rotates in the direction of the arrow, the fuel flows in the direction of the arrow.
-3 is the suction port, and 15-4 is the discharge port. FIG. 4 shows an example in which the electronically controlled carburetor of the present invention is used in a motorcycle engine 24. Each cylinder has one carburetor, but the rotary fuel pump 15 is commonly used for each carburetor. , a fuel nozzle 18 through which the pump supplies fuel is branched to each carburetor. 25 is an air cleaner. In the electronically controlled carburetor of the present invention, in order to simplify the structure of the carburetor, a pilot system (low speed fuel system)
It is also possible to eliminate the main fuel system and use only the rotary fuel pump, but it is difficult to perform appropriate control over the entire operating range with only the rotary fuel pump.

The advantages of the electronically controlled vaporizer according to the present invention can be summarized as follows: (1) Since there is no bypass port that requires high precision in setting and processing the vaporizer, the development period is shortened and productivity is increased. improves.

(2) Since there is no chiyoke valve, suction efficiency is improved.

(3) Compared to conventional vaporizers, not only connection but also overall setting is easier.

(4) Various corrections by electronic control, i.e. starting power increase,
Since warming up, acceleration, and output are increased, there is no need for a starter carburetor, accelerator pump, or power system in addition to the above-mentioned choke valve, which simplifies the carburetor configuration and provides appropriate fuel flow control. be able to.

(5) Three-way point control is possible by feedback of the oxygen concentration signal in the exhaust gas.

(6) Idle-up function can be provided by using an idling speed control device (ISC).

etc.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the electronically controlled carburetor of the present invention, Fig. 2 is a block diagram of the control system, Fig. 3 is a sectional view of an embodiment of the rotary fuel pump, and Fig. 4 is for motorcycles. FIG. 5 is a schematic diagram of the case where the electronically controlled carburetor of the present invention is used in an engine. FIG. 5 shows an example of an ultrasonic atomization device. 1... Carburetor body, 2... Main intake passage, 4...
Small bench lily, 6... Main jet, 7
...Main air jet, 8...Bleed pipe, 9...Main nozzle, 10...Pilot jet, 11...Pilot air jet, 12
... Pilot outlet, 13 ... Pilot screw, 14 ... Throttle valve, 15 ... Rotary fuel pump, 16 ... Control circuit, 18 ... Fuel nozzle, 19 to 22 ... Input signal, 23 ... Accelerator Pedal, 24...engine.

Claims (1)

[Scope of claims for utility model registration] (1) Main jet 6, main air jet 7,
A carburetor without a choke valve, consisting of a main fuel system consisting of a bleed pipe 8 and a main nozzle 9, and a low-speed fuel system consisting of a pilot jet 10, a pilot air jet 11, a pilot outlet 12, and a pilot screw 13. and a control circuit 16 based on a microprocessor unit that inputs and calculates various engine operating parameter signals, atmospheric condition signals, and engine cranking signals and outputs a fuel supply signal, and an output of the control circuit 16. A rotary fuel pump 15 whose rotation speed is controlled by a rotary fuel pump 15 whose fuel flow rate is adjusted according to the rotation speed, and a main intake passage of a carburetor connected to the outlet of the fuel pump 15. Inside,
An electronically controlled carburetor comprising a fuel supply system consisting of a fuel nozzle 18 that opens upstream of a throttle valve 14 of the carburetor. (2) At least supplement the connection between the low-speed fuel system and the main fuel system, increase the starting amount, and increase the warm-up amount in the fuel supply system consisting of the rotary fuel pump 15 whose rotation speed is controlled by the control circuit 16. ,
An electronically controlled carburetor according to claim (1) of the above-mentioned utility model registration, which is equipped with an acceleration increase and enrichment function. (3) The rotary fuel pump 15 whose rotation speed is controlled by the control circuit 16 is driven directly or at a reduced speed by a stepping motor. Electronically controlled vaporizer described in (2). (4) Claim No. 1, wherein the discharge side of the rotary fuel pump 15 communicates with a fuel nozzle that opens upstream of the carburetor throttle valve 14.
Electronically controlled vaporizer as described in paragraph or paragraph (3). (5) A downdraft type carburetor with an open bench lily has a fuel nozzle 18 above the small bench lily 4 that is substantially concentric with the small bench lily and opens downward, and this nozzle is connected to the rotary fuel pump 15. Paragraph (1) or (4) of the above utility model registration claim that communicates with the discharge side of the
Electronically controlled vaporizer as described in section. (6) Claim No. 1 of the above utility model registration claim, wherein the opening of the fuel nozzle 18 communicating with the discharge side of the rotary fuel pump 15 is provided with ultrasonic atomization means.
An electronically controlled vaporizer as described in paragraph (4) or paragraph (5).