JPS62129551A - Feedback controlled carburetor - Google Patents

Abstract

PURPOSE:To make carbon preventable from sticking to a mixture compensating slow-air feed port in utilization of detergency by dint of slow-system fuel, by opening the said air feed port to a slow mixture passage at the downstream side of a slow fuel jet. CONSTITUTION:A feedback controlled carburetor is provided with a main fuel passage 25 installing a main jet 3 side by side and an auxiliary fuel passage installing a fuel orifice 7 to be opened or closed by a valve 6 of a solenoid valve 4, and it sprays fuel out of both these fuel passages to the inside of a venturi 10 from a main nozzle 9 by way of a main well 2. And, it is also provided with a slow fuel passage 12 to be branched off from the main fuel passage 25, having the slow fuel sprayed out of an idle hole 17 and a bypass hole 18. In this case, a mixture compensating slow-air feed port 21 is installed in a slow mixture passage 20 at the downstream side of a slow fuel jet 22, whereby carbons ticking to the said feed port 21 is made so as to be eliminable by dint of a fuel flow.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a feedback carburetor, and particularly to a feedback carburetor that prevents clogging of the slow passage due to adhesion of carbon to the supply port of slow air for mixture correction to the primary slow passage. This invention relates to a vaporizer suitable for improving.

[Background of the invention]

In the conventional feedback vaporizer,
As described in Japanese Patent No. 167942, a slow air supply port for correcting the mixture to the primary slow passage was provided in the slow air passage upstream of the slow fuel injection port. As a result, carbon contained in blow pie gas etc. adheres to the supply port of the slow air for mixture correction to the primary slow passage, which further narrows the diameter of the slow passage and makes the mixture ratio at low speeds too rich. There was a problem that had a negative impact on emissions.

[Purpose of the invention]

An object of the present invention is to solve this problem by providing a supply port for the mixture correction slow air of the feedback carburetor to the primary slow passage in the mixture passage downstream of the slow fuel injection port. An object of the present invention is to provide a feedback vaporizer that utilizes the cleaning power of the present invention and has the function of preventing clogging of the slow passage.

[Summary of the invention]

Carbon contained in blow-by gas enters the slow air passage for mixture correction and adheres to the slow air passage.
? ? This will further reduce the slow passage diameter. Therefore, in order to wash away the carbon that has entered by using the cleaning power of the fuel, a slow air supply port for correcting the mixture to the primary side slow passage is provided in the mixture passage downstream of the slow fuel injection port. This prevents carbon clogging.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a structural explanatory diagram of a conventional feedback vaporizer. 1 is a float chamber, and fuel supply from float chamber 1 to main well 2 is as follows:
This is done using a main fuel passage for the fuel metered by the main jet 3 and a correction fuel passage for the fuel metered by the fuel orifice 7 whose opening and closing are controlled by the valve 6 interlocked with the plunger 5 of the duty solenoid valve 4.

This correction fuel passage is connected to the downstream side immediately below the main jet 3, and is configured to allow the fuel metered by the fuel orifice 7 to join the fuel metered by the main jet 3. This combined fuel is introduced into the learn well 2, where it is mixed with air coming in from the main air bleed 8, and is ejected from the main nozzle 9 into the venturi 10.

By the way, in a low-speed operating range where the opening degree of the throttle valve 11 is small, the negative pressure generated at the tip of the main nozzle 9 is small, so the fuel is not ejected from the main nozzle 9 but passes through the slow fuel passage 12 branched from the main fuel passage 25. Then, the air is metered again by the slow jet 13, and the air metered by the slow air bleed 14 and the mixture metered by controlling the opening and closing of the air orifice 16 by the valve 15 fixed to the plunger 5 of the duty solenoid valve 4. It is mixed with the corrected slow air and supplied to the engine through the idle hole 17 and the bypass hole 18.

Reference numeral 19 indicates an intake port for slow air for mixture correction. In addition, in a six-piece structure in which the mixture correction slow air supply ports 21 are provided in the slow air passage 24 on the upstream side of the slow fuel injection port 22, carbon contained in the blow-by gas as well as air is absorbed into the mixture correction slow air supply port 21. The air enters through the port 19, passes through the air mixture correction air passage 23, and attaches to the air mixture correction slow air supply port 21 of the slow air passage 24 upstream of the slow fuel injection port 22.

This accumulates and throttles the slow air passage 24, resulting in an overrich mixture.

An embodiment of the invention is shown in FIG.

The mixture correction slow air supply port 21 is provided on the slow mixture road 20 on the downstream side of the slow fuel injection port 22, and the mixture correction slow air supply port 21 is caused by the fuel ejected from the slow fuel injection port 22. The carbon attached to the
It is designed to be washed away using the cleaning power of the fuel.

〔Effect of the invention〕

According to the present invention, by a simple structural change in which the mixture correction slow air supply port is changed from the slow air passage upstream of the slow fuel injection port to the slow air mixture passage downstream of the slow fuel injection port, Using the cleaning power of slow fuel, carbon adheres to the air mixture correction slow air supply port.
Furthermore, it has the effect of preventing clogging of the slow passage.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram of a conventional feedback vaporizer;
FIG. 2 is a structural diagram of a feedback vaporizer showing an embodiment of the present invention. 1... Float chamber, 2... Main well, 3... Main jet, 4... Duty solenoid valve, 5
...Plunger, 6...Valve, 7...Fuel orifice, 8...Main air bleed, 9...
Main nozzle, 10... Venturi, 11... Throttle valve. 12... Slow fuel passage, 13... Slow jet, 14... Slow air bleed, 15... Valve,
16... Air orifice, 17... Idle hole, 18... Bypass hole, 19... Mixture correction slow air intake, 20... Slow mixture passage, 2
DESCRIPTION OF SYMBOLS 1... Mixture correction slow air supply port, 22... Slow fuel injection port, 23... Mixture correction air passage, 24...
... Slow air passage, 25... Main fuel passage.

Claims (1)

[Claims] 1. A feedback carburetor characterized in that a supply port for slow air for correcting the air-fuel mixture to the primary slow passage of the feedback carburetor is provided in a slow mixture passage downstream of a slow fuel injection port.