AADI ejector for heavy oil and alcohol-based fuel engine

Abstract

According to the AADI ejector for the heavy oil and alcohol-based fuel engine, the bottom of a valve rod is an expanded spherical end which is matched with a conical or arc-shaped injection hole in size, and an injection outlet is formed by a gap between the expanded spherical end and the conical injection hole. Fuel atomization can be achieved under the specific low-pressure working condition, and stable operation of an engine is guaranteed; stable and accurate flow metering is provided through the oil injection valve, fuel is mixed with compressed air in the oil-gas mixing cavity, and then through the special Laval structure of the air injection valve, the fuel is torn into micron-sized fine liquid drop particles at the throat pipe at a supersonic speed, so that the fuel can be directly ignited.

Description

Technical Field

[0001] The utility model relates to the technical field of internal combustion engines, in particular to an AADI injector for heavy oil and alcohol-based fuel engines. Background Art

[0002] The AADI injector assembly is a key component in an internal combustion engine. Its working principle is to accurately measure the fuel and inject it into a mixing chamber with an air pressure of 300~1000KPa through the injection valve. After mixing with compressed air in the mixing chamber, it is sprayed into the cylinder through the injection valve in the form of atomization. After mixing with air, a combustible mixture is formed and ignited directly in the combustion chamber. Currently, the existing diesel injectors used in spark ignition engines are generally high-pressure direct injection.

[0003] However, the existing AADI injectors still have the following disadvantages: 1. The fuel rail pressure is high, and the energy consumed to build up the pressure is high, which is not conducive to the use of small-displacement and high-power-to-weight ratio engines; 2. Since the atomization effect is not good enough, the fuel entering the cylinder is still difficult to ignite for alcohol-based fuels with high calorific value. Summary of the invention

[0004] The purpose of the utility model is to provide an AADI injector assembly to achieve fuel atomization under specific low-pressure conditions (fuel rail pressure is lower than 1MPa) to ensure stable operation of the engine; provide stable and accurate flow metering through the injection valve, the fuel is mixed with compressed air in the oil-gas mixing chamber, and then the special Rafael structure of the injection valve makes the fuel reach supersonic tearing into micron-sized fine droplets at the throat so that it can be directly ignited.

[0005] In order to achieve the above object, the technical solution of the utility model is as follows:

[0006] An AADI injector for a heavy oil and alcohol-based fuel engine, wherein an injection valve mounting seat is installed at the lower part of the injection valve, and a mixing chamber is formed in the injection valve mounting seat; an injection valve is connected and installed below the mixing chamber, a valve core is arranged at the upper part of a valve body of the injection valve, the valve core is fixedly connected to the upper part of a valve stem, the lower end surface of the valve core is connected to the upper end of a compression spring, and the lower end of the compression spring is connected to the upper end of a magnetic conductive tube; the magnetic conductive tube is fixed to the valve body, and an electromagnet is arranged on the outer side of the magnetic conductive tube; the upper part of the valve stem is in a hollow tubular shape, the tube inlet is connected to the mixing chamber, the tube outlet is arranged at the side of a neck portion close to the bottom, and a cavity is formed between the neck portion and the inner wall of the injection hole; the bottom of the valve stem is an enlarged spherical end, which matches the size of a conical or arc-shaped injection hole, and the gap between the enlarged spherical end and the conical injection port forms an injection outlet.

[0007] When the electromagnet is energized, the magnetic tube is magnetized to generate suction on the upper valve core. The valve core overcomes the resistance of the compression spring and moves downward together with the valve stem. That is, a gap is created between the ball head at the lower end of the valve stem and the conical outlet to form an outlet, thus realizing the opening of the jet valve.

[0008] The fluid flows from the inner cavity of the hollow valve stem toward the air outlet, and enters the cavity, i.e., the front cavity of the Rafale throat (annular cavity inclined toward the outlet end) through the air outlet. The cross-section of the annular cavity reaches its maximum at the neck portion at the ball head end. When the valve stem is pushed open, a narrow injection outlet is formed by the gap between the spherical surface of the ball head end and the conical injection port, which is the throat of the Rafale tube. The fluid flows through the throat at high speed, forming the first stage structure of the Rafale tube. Afterwards, the fluid reaches the conical injection port, and the cross-sectional area increases abruptly, forming the second stage of the Rafale tube. The internal energy of the fluid is violently released, forming a high-speed atomized airflow injection, thereby completing the atomization injection.

[0009] The upper part of the fuel injection valve is connected to the oil cap.

[0010] An oil-gas mixing seat is arranged below the mixing chamber, the lower end of which is connected to an air jet valve, and the diameter of the through hole at the lower end of the oil-gas mixing seat is smaller than the diameter of the inlet at the upper end. The oil-gas mixing seat reduces the passage cross section of the fluid and increases the turbulent kinetic energy of the fluid, so that the two high-speed fluids are fully mixed in the cavity to achieve a better atomization effect.

[0011] The working principle of the utility model is as follows:

[0012] The fuel enters the injection valve from above, and the injection valve sprays the fuel into the mixing chamber with an air pressure of 300~1000KPa in an accurate manner. After mixing with the compressed air in the mixing chamber, it is sprayed into the cylinder through the injection valve in an atomized form. After mixing with the air, a combustible mixture is formed and ignited directly in the cylinder combustion chamber of the engine.

[0013] Advantages of utility models

[0014] The utility model utilizes a valve stem structure similar to that described in an existing patent: a compressible fluid high-speed injection metering valve (202320627968.1), optimizes the structure of the injection end of the AADI injector, and utilizes the Laval tube principle. Without establishing a large fuel rail pressure, the metering valve outlet injection speed can be greatly increased, the flow rate and flow of the fluid can be improved, and the fuel atomization effect can be improved.

[0015] 2. The fuel atomization effect of the AADI injector of the utility model is good, and it can be used in small-displacement engines with high power-to-weight ratio; at the same time, it also has a good ignition effect on heavy oil and alcohol-based fuels with high calorific value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the internal structure of the utility model;

[0017] The serial numbers and component names in the figure are: 1-oil cap; 2-injection valve; 3-injection valve mounting seat; 4-oil-gas mixing seat; 5-valve core; 6-compression spring; 7-electromagnet; 8-magnetic tube; 9-valve stem; 10-mixing chamber. DETAILED DESCRIPTION Example 1

[0018] An AADI injector for a heavy oil and alcohol-based fuel engine, wherein an injection valve mounting seat 3 is installed at the lower part of an injection valve 2, and a mixing chamber 10 is formed in the injection valve mounting seat 3; an injection valve is connected and installed below the mixing chamber 10, a valve core 5 is arranged at the upper part of a valve body of the injection valve, the valve core 5 is fixedly connected to the upper part of a valve stem 9, the lower end surface of the valve core 5 is connected to the upper end of a compression spring 6, and the lower end of the compression spring 6 is connected to the upper end of a magnetic conductive tube 8; the magnetic conductive tube 8 is fixed to the valve body, and an electromagnet 7 is arranged on the outer side of the magnetic conductive tube 8; the upper part of the valve stem 9 is hollow tubular, the tube inlet is connected to the mixing chamber 10, the tube outlet is arranged at the side of a neck portion near the bottom, and a cavity is formed between the neck portion and the inner wall of the injection hole; the bottom of the valve stem 9 is an enlarged spherical end, which matches the size of a conical injection hole, and the gap between the enlarged spherical end and the conical injection port forms an injection outlet.

[0019] The upper part of the fuel injection valve 2 is connected to the oil cap 1 .

[0020] An oil-gas mixing seat 4 is arranged below the mixing chamber 10 , the lower end of the oil-gas mixing seat 4 is connected to an injection valve, and the diameter of the through hole at the lower end of the oil-gas mixing seat 4 is smaller than the diameter of the inlet at the upper end.

Claims

1. An AADI injector assembly for a heavy oil or alcohol-based fuel engine, characterized in that: An injection valve mounting seat (3) is mounted at the lower part of the injection valve (2), and a mixing chamber (10) is formed in the injection valve mounting seat (3); an injection valve is connected and mounted below the mixing chamber (10); a valve core (5) is arranged at the upper part of the valve body of the injection valve, the valve core (5) is fixedly connected to the upper part of the valve stem (9), the lower end surface of the valve core (5) is connected to the upper end of a compression spring (6), and the lower end of the compression spring (6) is connected to the upper end of a magnetic conductive tube (8); the magnetic conductive tube (8) is fixed to the valve body, and an electromagnet (7) is arranged outside the magnetic conductive tube (8); the upper part of the valve stem (9) is in a hollow tubular shape, the tube inlet is connected to the mixing chamber (10), and the tube outlet is arranged at the side of a neck portion near the bottom, and the neck portion and the inner wall of the injection hole form a cavity; the bottom of the valve stem (9) is an enlarged spherical end, which matches the size of the conical injection hole, and the gap between the enlarged spherical end and the conical or arc-shaped injection port forms the injection outlet.

2. The AADI injector assembly for heavy oil and alcohol-based fuel engines according to claim 1, characterized in that: The upper part of the fuel injection valve (2) is connected to the fuel cap (1).

3. The AADI injector assembly for heavy oil and alcohol-based fuel engines according to claim 1, characterized in that: An oil-gas mixing seat (4) is arranged below the mixing chamber (10); the lower end of the oil-gas mixing seat (4) is connected to an air injection valve; and the diameter of the through hole at the lower end of the oil-gas mixing seat (4) is smaller than the diameter of the inlet at the upper end.

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