JP3114330U - Engine fuel changer - Google Patents

Abstract

A fuel switching device capable of instantaneous switching at a low price without using a solenoid valve.
The main nozzle of the carburetor is directly opened and closed by a needle valve attached to the carburetor and inserted into the diaphragm. When the diaphragm is displaced by the pressure applied to the pressure chamber of the negative pressure cock, the interlocking needle valve is seated on or separated from the valve seat provided on the main nozzle.
The pressure applied to the pressure chamber is obtained by opening and closing the fuel cock of the cylinder.
The fuel controller for supplying gaseous fuel and the pressure chamber of the negative pressure cock are branched immediately after the cock, and the fuel pressure is transmitted to the pressure chamber simultaneously with the fuel supply by opening the cock.
[Selection] Figure 2

Description

  This invention relates to fuel switching widely used in engines such as generators, pumps, outboard motors, and motorcycles, and more particularly, to a switching device capable of instantaneously and inexpensively switching between gas fuel and liquid fuel. .

In recent years, gas and liquid fuels such as gasoline, kerosene, propane, and butane are often used in combination with small engines that drive generators, pumps, outboard motors, sprayers, and the like.
In an engine using a carburetor, when switching between gaseous fuel and liquid fuel while the engine is operating, the liquid fuel stored in the float chamber becomes an obstacle and the engine stops.
In other words, if the engine is operated with liquid fuel, and the gas fuel is supplied to the engine by closing the cock of the liquid fuel tank and opening the cylinder cock, the fuel stored in the float chamber is supplied together with the gas fuel. This is because the air-fuel ratio becomes dense.
Conversely, when switching from the gas fuel operation to the liquid fuel, the liquid chamber is not filled with the liquid fuel, so that the fuel runs out and the engine stops.
As a countermeasure against this, a method may be considered in which a fuel shut-off valve is provided directly on the main nozzle of the carburetor and a shut-off valve is provided on the gas fuel side at the fuel controller inlet.
In this manner, the liquid fuel in the float chamber can be switched while maintaining the specified level, so that no trouble is caused even if the fuel is switched from any fuel.

A fuel supply apparatus employing this method has already been disclosed in the following literature.
JP-A-10-299521 However, this device uses two electromagnetic valves and requires a changeover switch, a battery, a charging device, and the like. For this reason, the apparatus is not only expensive, but also increases in weight and equipment volume.

  This device does not use an electromagnetic valve for the purpose of reducing the cost of the above apparatus, but ejects liquid fuel from the main nozzle of the cab using the fuel pressure of gas fuel (pressure for supplying fuel to the engine, about 2.94 kpa). The purpose is to stop.

It is important that the engine for driving household equipment is inexpensive even if a multi-fuel can be used. For this reason, it is necessary to enable instantaneous switching between gaseous fuel and liquid fuel without using a solenoid valve.
It aims at solving the above-mentioned subject.

In order to achieve the above object, the fuel pressure of gaseous fuel is used to block the ejection of liquid fuel from the main nozzle of the carburetor.
As a shut-off method, a pressure type open / close valve (negative pressure cock) is provided under the float chamber of the carburetor. In general, the negative pressure cock has a structure in which a spring is provided on the side of the diaphragm where the negative pressure is applied, the valve is pressed, and the valve is opened when negative pressure is applied.
However, in this proposal, since the fuel pressure is positive (+), a spring is provided on the opposite side of the pressure chamber defined by the diaphragm.
This chamber is provided with a needle valve which is inserted into the diaphragm at the same time as the spring.
Since the diaphragm is pushed down by the spring force when using liquid fuel, the needle valve is also lowered from the valve seat of the main nozzle and opened.
When supplying liquid, the pressure chamber of the negative pressure cock is under negative pressure generated by the adapter, but when the fuel pressure of gaseous fuel is applied, this spring is pushed up to seat the needle valve on the valve seat and supply liquid fuel To stop.

That is, the supply of liquid fuel is stopped as soon as gaseous fuel is supplied from the gas cylinder to the engine, and when the supply of gaseous fuel is stopped, the valve seat of the main nozzle is opened and the liquid fuel is supplied immediately.
Negative pressure cocks are cheaper than electromagnetic valves. Moreover, it functions with a single valve, eliminating the need for parts such as batteries.

The above device has made it possible to make multi-fuels for engines for household appliances, which require severe initial costs.
Although the price is slightly higher than gasoline-powered engine generators, it can be made into a product that is almost the same as conventional products in terms of size and weight.

Hereinafter, an embodiment of the present plan will be described with reference to the drawings.
For convenience, an engine generator using LPG as the gas fuel and gasoline as the liquid fuel will be described.
FIG. 1 shows a layout of the generator.
A gasoline tank 3 is arranged above the engine 1 and a generator 2 driven by the engine 1.
The gasoline is piped and supplied from the gasoline tank to the float chamber 7 of the carburetor 4 through the cock. The LPG is regulated by a regulator from a cylinder 14 provided sideways and supplied to the fuel controller 5.

An engine generator fuel switching device is shown in FIG.
A negative pressure cock 8 is provided below the float chamber 7 of the carburetor. A needle valve 11 is inserted into the center of the diaphragm 9 of the negative pressure cock, and the needle valve 11 blocks the jet of gasoline from the main nozzle 13. A valve seat 13 </ b> A is press-fitted into the main nozzle 13, and the injection of gasoline is blocked by the ascent and close contact of the needle valve 11.
When the fuel pressure is applied to the lower part of the diaphragm 9, the needle valve 11 is pushed up against the spring 10 and is seated on the valve seat through a hole in the bottom of the chamber processed concentrically with the main nozzle.
The tip of the needle valve may use fluoro rubber for reliable shut-off.

The LPG is regulated by a regulator 16 provided in the cylinder 14, branches immediately after the gas cock 17, and communicates with the fuel controller 5 and the negative pressure cock 8.
When the gas cock 17 is opened, LPG is supplied to the controller, and at the same time, the fuel pressure is applied to the pressure chamber of the negative pressure cock 8 to pressurize the diaphragm 9.
The needle valve 11 inserted into the diaphragm due to the deformation of the diaphragm due to the pressurization is seated on the valve seat 13A in the main nozzle and shuts off the injection of gasoline.
This makes it possible to easily and instantly switch fuel from any fuel.

Next, the operation when the best mode is implemented will be described.
First, when starting with gasoline, the cock of the gasoline tank 3 is opened and the float chamber 7 is filled with gasoline. The gasoline in the chamber is supplied to the main nozzle 13 through the main jet 12 and is maintained at an appropriate oil level in the nozzle.
Since the valve seat 13A of the main nozzle is opened by the spring 10, the ignition switch is turned on and the starter is pulled to start and generate electricity.
In this state, when the main plug 15 of the LPG tank 14 that is laterally attached is opened and the gas cock 17 that has passed through the regulator 16 is opened, the needle valve 11 that is inserted into the diaphragm by the fuel pressure of the LPG is seated on the valve seat 13A and the gasoline from the main nozzle. Block the eruption. This immediately enters LPG operation.

When starting with LPG, gasoline is first stored in the float chamber 7, but since the injection of gasoline from the main nozzle is shut off as described above when the gas cock is opened, it is supplied to the controller 5. Easy to start with LPG. When switching to gasoline, just close the gas cock and start gasoline operation. This is because when the cock is closed, the pressure chamber of the negative pressure cock changes from positive pressure to negative pressure, and the valve seat 13A is opened by the spring.
Even if it starts from the gas or liquid fuel by the said form, it can switch instantaneously.

The present invention is one of the contents being developed with the goal of being applied to multi-fuel household generators and pumps especially considering disasters.
Due to the failure of the lifeline at the time of disaster, the supply of gas, water, and electricity will be stopped, and even emergency work and fire fighting will be delayed. In the case of an emergency, it is desirable to be able to use any fuel (for example, gasoline, kerosene, propane, butane, etc.) in a general household, and it is necessary to continue operation for a long time.
For this purpose, a simple switching device capable of instantaneously switching between liquid fuel and gaseous fuel can be provided at low cost.

It is an arrangement plan of an engine generator according to the present invention. It is explanatory drawing which shows embodiment of the switching method of the gaseous fuel and liquid fuel concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Generator 3 Gasoline tank 3A Kerosene tank 4 Carbator 5 Fuel controller 6 Adapter 7 Float chamber 8 Negative pressure cock 9 Diaphragm 10 Spring 11 Needle valve 12 Main jet 13 Main nozzle 13A Valve seat 14 Cylinder 15 Cylinder head plug 16 Regulator 17 For gas cock

Claims (1)

  A fuel supply device for an engine that uses gas and liquid as fuel, and in the engine that supplies gas fuel from a carburetor for supplying liquid fuel to the engine and an adapter provided upstream thereof, pressure is applied to the lower part of the float chamber of the carburetor. A fuel switching device characterized by having a structure in which a valve seat provided on a main nozzle of a carburetor is opened and closed by a supply pressure of gaseous fuel.

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