JPS633421Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fuel injection device for an internal combustion engine that injects air together with fuel to make the fuel more atomized by the air.

Generally, in internal combustion engines such as gasoline engines and diesel engines, it is important to atomize the fuel in order to improve performance. In addition, some conventional diesel engines have adopted a system that atomizes the fuel by injecting air with the fuel, but the air compressor was inefficient, so the airless injection system was better in terms of overall fuel efficiency. It is said to be excellent,
At present, the airless injection method is the mainstream. However, due to current exhaust gas regulations and other factors, the fuel efficiency of airless injection internal combustion engines is decreasing, so if a compression method with high air compression efficiency is adopted, air injection internal combustion engines can be made that are more fuel efficient than airless injection systems. It is easy to provide.

This idea was made in view of these circumstances,
The present invention aims to provide a fuel injection device for an internal combustion engine equipped with a piston that can efficiently pressurize air, thereby improving performance and fuel efficiency by atomizing the injected fuel.

This invention will be described in detail below with reference to an illustrated embodiment. In the figure, 1 is a main body of an internal combustion engine, which has a plurality of cylinders 2, each of which houses a piston 3. Reference numeral 4 denotes an injection nozzle main body provided for each cylinder 2, in which a pressurizing chamber 4a is formed, and a piston 5 consisting of a large diameter portion 5a and a small diameter portion 5b inside the pressurizing chamber 4a.
The large diameter portion 5a side of is accommodated. The piston 5 is always urged upward by a compression spring 6 housed in the lower chamber ₄₁ of the pressurizing chamber 4a, and the small diameter portion 5b side of the piston 5 is inserted into the hydraulic chamber 4c from below. There is. Fuel or hydraulic oil is supplied to the hydraulic chamber 4c from a hydraulic source (not shown) during fuel injection to press the piston 5 downward.

On the other hand, the upper chamber ₄₂ of the pressurizing chamber 4a is communicated with the inside of the cylinder 2 via a passage 4d, and fuel is supplied to the lower chamber ₄₁ via a fuel passage 4e. In addition, the bottom of the lower chamber 4 ₁ contains the fuel supplied into the lower chamber 4 ₁ and the cylinder 2 introduced into the lower chamber 4 ₁ from the nozzle hole 4 f at the tip of the nozzle body 4.
An atomizer 7 is provided to mix the intake air inside the cylinder 2, and is configured to inject a mixture of fuel and air inside the lower chamber ₄₁ into the cylinder 2 through the nozzle hole 4f as the piston 5 descends.

This idea has been described in detail above, so that when hydraulic pressure is supplied to the hydraulic chamber 4c during fuel injection, the piston 5 is pushed downward against the compression spring 6 by the pressure receiving area of the small diameter portion 5b of the piston 5. During the pressurization process, the intake air and fuel in the lower chamber ₄₁ introduced from the cylinder 2 are pressurized by the large diameter portion 5a, and are injected into the cylinder 2 from the atomizer 7 and the injection hole 4f. Also, since the air expands at this time and further atomizes the fuel, it is possible to improve combustion efficiency and performance accordingly, and the air is pressurized by the piston 5, which operates with high pressure and a small amount of oil pressure. As a result, energy loss in the oil passage is reduced compared to conventional systems that operate the piston with low pressure and large amounts of oil pressure, which also improves air compression efficiency and improves fuel efficiency.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of this invention. 1 is the engine body, 2 is the cylinder, 4 is the injection nozzle body, 4a is the pressurizing chamber, 4c is the hydraulic chamber, 4e is the fuel passage, 4f is the injection hole, 4 ₁ is the lower chamber, 5 is the piston,
5a is a large diameter portion, and 5b is a large diameter portion.

Claims (1)

[Scope of utility model registration request] In a device that atomizes fuel by simultaneously injecting fuel and air from an injection nozzle body 4 provided for each cylinder 2 of an engine body 1, a large diameter portion 5a and a small diameter portion 5b are provided in the injection nozzle body 4. The large diameter portion 5a of the piston 5 forms a lower chamber ₄₁ and an upper chamber _42.
A pressurized chamber 4a is provided, the lower chamber ₄₁ communicates with the inside of the cylinder 2 via a nozzle hole 4f, and the upper chamber ₄₂ communicates with the inside of the cylinder 2 via a passage _4d . is provided with an atomizer 7 that mixes and heats the fuel introduced into the lower chamber 4 ₁ through the fuel passage 4 e and the intake air introduced into the lower chamber 4 ₁ through the nozzle hole 4 _f . A compression spring 6 is provided inside the piston 5 to urge the piston 5 upward.
The small-diameter portion 5b is provided above the pressurizing chamber 4a and faces a hydraulic chamber 4c to which hydraulic pressure is supplied from a hydraulic pressure source during fuel injection.