JPH0571421A - Fuel supplying device for liquefied petroleum gas engine - Google Patents

Abstract

PURPOSE:To independently dispose a fuel supply path and an air intake path so as to regulate a flow rate of fuel and a flow rate of air in association with each other. CONSTITUTION:Operation of a fuel flow rate regulator 39 disposed on the way of a fuel supply path 43 is associated with operation of an air flow rate regulator 75 provided on the way of an air intake path 47. The fuel supply path 43 is communicated only at the time of intake of an engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for a liquefied gas engine which uses liquefied petroleum gas sealed in a pressure vessel as a fuel.

[0002]

2. Description of the Related Art Conventionally, in a liquefied gas engine, fuel is supplied through a carburetor or the like as in an engine using gasoline as fuel.

[0003]

When the fuel used is gasoline, the amount of negative pressure in the intake passage of the carburetor and the gasoline discharge hole that is opened facing the intake passage are appropriate for the amount of fuel required by the engine. It is supplied in a metered amount according to the correlation with the hole diameter of liquefied petroleum, but in the case of liquefied petroleum gas sealed in a pressure vessel, it is pressurized to a pressure above atmospheric pressure and supplied to the intake passage, so when fuel is gasoline As described above, it is difficult to control the fuel by the negative pressure in the intake passage. Although there is a system to supply the pressure equal to or less than the atmospheric pressure, it requires a certain temperature to complete vaporization due to the property of liquefied petroleum gas. Since they are mixed, it is difficult to supply the fuel at the suction negative pressure of the carburetor like gasoline, and the pressure reducing device is large and expensive.

[0004]

According to the present invention, a fuel flow rate adjusting device is provided in a fuel supply passage of liquefied petroleum gas and an air flow adjusting device is provided in an air intake passage, and the fuel supply passage and the air intake passage are separately provided. The fuel flow rate adjusting device and the air flow rate adjusting device are provided so as to communicate with each other, and the fuel supply passage is provided so as to communicate only when the engine is sucked.

[0005]

When the piston descends and the air intake passage opens as the crankshaft rotates, the atmosphere enters the cylinder from the air cleaner through the air intake passage. Fuel enters the carburetor chamber from the gas cylinder and is vaporized, and passes through the fuel supply passages such as the pressure adjustment chamber and the metering device, and then the crankcase when the piston rises.
It is sucked into the cylinder, is supplied into the cylinder when the piston descends, is mixed with air, and ignites and explodes. Since the fuel flow rate adjusting valve and the air flow rate adjusting valve are provided so as to interlock with each other, the amounts of fuel and air can easily maintain a predetermined mixing ratio. In addition, since the fuel supply path communicates only with the intake of the engine, the pressure does not flow backward and the vaporization of the fuel is not hindered.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a cylinder 5 is fixed above a crankcase 3 of an engine 1, an exhaust hole 9 communicating with a muffler 7 on one side of the cylinder 5, and an intake hole communicating with an air cleaner 11 on the other side. 13 is open. A crankshaft 15 is rotatably supported by the crankcase 3, and the crankshaft 15
One end of a connecting rod 19 is connected to a crank arm 17 provided in the cylinder via a crank pin 21, and the other end of the connecting rod 19 is slidable in the cylinder 5 and a piston 23 and a piston pin 2.
It is connected through 5.

A fuel discharge hole 2 at one end of a portable pressure vessel (hereinafter referred to as a gas cylinder) 27 in which liquefied petroleum gas is enclosed.
9 is supported by the socket fitting 31 and the other end is detachably supported by the spring holder 33. The pressure regulator 37, the vaporization chamber 35,
A fuel supply passage 43 communicating with the cylinder 5 via the fuel flow rate adjusting device 39 and the opening / closing valve 41 is configured. Air intake path 4
Reference numeral 7 is composed of an air cleaner 11, an air flow rate adjusting device 75 having one end communicating with the air cleaner 11 and the other end communicating with an intake hole 13 opening to a side wall of the cylinder 5, and the intake hole 11. . The fuel flow rate adjusting device 39 and the air flow rate adjusting device 75 are swingably connected by a connecting rod 83.

The fuel flow rate adjusting device 39 of FIG. 2 is constructed as follows. A swing valve 57 and a gas inlet 59, which are driven by a shaft 55 so as to open and close the opening 53 inside the gas outlet 51.
And are provided in the compartment 61. The rocking valve 57 is connected at its free end to a diaphragm 63 mounted so as to partition one side of the compartment 61, so that the diaphragm 63 acts on a side surface opposite to the rocking valve 57. It is pressed by the coil spring 65, which in turn presses the rocking valve 57 in the direction of opening the opening 53 of the gas outlet 51. One end of the compression coil spring 65 is supported by a cylindrical case 67, and the case 67 is provided in a container 71 having an opening in the atmosphere by sandwiching the screw portion 69 provided on the outer peripheral portion and the diaphragm 63. It engages with the threaded portion 73 to project the other end out of the container 71.

As shown in FIG. 3, the air flow rate adjusting device 75 has a shaft 79 which is rotatably supported by penetrating the pipe 77 and has a taper shape. A hole 81 communicating with the conduit 77 is formed by a seal 87, a spring 89, and a retainer 91.

In the above embodiment, the gas cylinder 3
The liquefied petroleum gas in the inside is supplied from the gas inlet 59 into the compartment 61. Therefore, as the pressure inside the compartment 61 increases, the diaphragm 63 is moved against the action of the compression coil spring 65 to move the swing valve 57. The opening 53 of the gas outlet 51 is swung so as to be closed to stop the inflow of fuel. The rocking valve 57 opens and closes the gas outlet 51 to adjust the amount of fuel supplied to the engine. The operation of the rocking valve 57 can be controlled by the magnitude of the pressure in the compartment 61 that moves the diaphragm against the action of the compression coil spring 65. Since the pressing force of the compression coil spring 65 can be easily adjusted by moving and fixing it in the axial direction with the screw portion of the case 67, the pressure in the compartment 61 becomes a value balanced with the pressing force of the compression coil spring 21. Therefore, the required amount of fuel can be continuously supplied to the engine.

Further, by separately providing the fuel supply passage 43 and the air intake passage 47, the influence of the negative pressure of the intake passage is removed, and the fuel is not discharged unnecessarily from the air inflow passage 47 to the atmosphere. By interlocking the operations of the air flow rate adjusting device 75 for adjusting the amount and the fuel flow rate adjusting device 39, it is possible to accurately adjust and supply the required amount of fuel according to the intake air amount.

Further, since the fuel supply passage 43 is provided so as to communicate with each other only when the engine is sucked, the pressure does not flow backward and the vaporization of the fuel is not hindered.

FIG. 4 shows another embodiment, in which the case 67 is moved up and down via the rotating cam 85 to adjust the pressing force of the coil spring 67.

The fuel flow rate adjusting device 39 of the present invention can also have the function of the pressure adjuster 37.

[0016]

According to the present invention, the amount of fuel and air can be easily adjusted by adjusting the fuel flow rate adjusting device 39 without the need to reduce the pressure of fuel to atmospheric pressure, and therefore the engine. The output of can be easily controlled.

Further, by communicating the fuel supply passage only when the engine is sucked, the pressure does not flow backward and the vaporization of the fuel is not hindered.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a side sectional view of a main part.

FIG. 3 is a side sectional view of another main part.

FIG. 4 is a side sectional view of another embodiment.

[Explanation of symbols]

 1 Engine 27 Pressure Vessel (Gas Cylinder) 39 Fuel Flow Rate Regulator 43 Fuel Supply Channel 75 Air Flow Rate Regulator 47 Air Intake Channel

Claims (1)

[Claims] 1. A fuel flow rate adjusting device 39 is provided in a fuel supply passage 43 which is provided so as to connect the engine 1 and a pressure vessel 27 in which liquefied petroleum gas is sealed, and the air is provided separately from the fuel supply passage 43. An air flow rate adjusting device 75 is provided in the air intake passage 47 provided to supply the fuel flow rate adjusting device 39 with the operation of the fuel flow rate adjusting device 39 and the air flow rate adjusting device 75. A fuel supply device for a liquefied gas engine, characterized in that the fuel supply device is provided so as to communicate with each other only when inhaling.