JPH0475390B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection valve for a diesel engine.

[Conventional technology]

FIG. 1 shows an example of a conventional diesel engine fuel system.

In the figure, 11 is a cam, 12 is a roller, 13 is a fuel injection pump, 14 is an injection pipe, 16 is a fuel injection valve, 31 is a fuel chamber, and 32 is a piston.

An injection pump 1 driven by a cam 11 via a roller 12 and having a built-in plunger (not shown)
3, the fuel oil is pumped through the injection pipe 14 by the fuel valve 16, and the fuel is injected into the combustion chamber 31 for compression ignition combustion.

[Problem to be solved by the invention]

This type of engine achieves good thermal efficiency by atomizing fuel by injecting it at high pressure, passing it through the combustion chamber, mixing it with high-temperature, high-pressure compressed air, and igniting it. It's summery. However, in this type, the fuel is atomized by shearing between the high-speed jet of the fuel itself and the compressed air, but the formed spray stream has a rich mixture at the center and a lean mixture at the outside. As a result, combustion is insufficient and a lot of smoke is generated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve that can solve the above problems, improve combustion in a diesel engine, and reduce smoke.

[Means and actions for solving problems]

The fuel injection valve according to the present invention has a fuel injection hole 15 that injects high-pressure fuel oil that is intermittently pumped from a fuel injection pump through an injection pipe into a cylinder of an engine.
1 is a fuel injection valve having a nozzle 162 having a fuel oil passage 153 bored at the tip and having a fuel oil passage 153 at the axial center communicating with the nozzle hole. Fuel passage hole 1 in the part
52a is bored through the fuel oil passage 153 of the nozzle.
A fuel valve needle 152 that opens and closes, a reservoir 159 that is formed in the outer cylinder 157 of the injection valve and that is blocked from the fuel oil passage 153 and stores water or a mixed oil of water and oil, and the outer cylinder. an on-off valve 158 that automatically opens and closes between the nozzle hole and the reservoir by the pressure of the water or the mixed oil of water and oil; a flow path to the fuel injection hole 151 of the nozzle;
It is characterized in that the flow path to the nozzle hole 242 of the outer cylinder is configured as a separate flow path that is cut off from each other.

This promotes the atomization of the fuel, promotes the movement of the spray, increases the penetration force of the fuel, improves the formation of the air-fuel mixture, and improves combustion.

〔Example〕

An embodiment of the fuel injection valve of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 is an explanatory diagram showing an outline of an embodiment according to the present invention, and FIG. 3 is a sectional view showing a fuel injection valve of the embodiment.

In FIGS. 2 and 3, reference numeral 15 denotes a fuel injection valve, which includes a nozzle 162 having a fuel injection hole 151 at the tip of a fuel oil passage 153 communicating with the injection pipe 14, and a fuel valve needle biased by a fuel valve spring 154. 15
2 closes the fuel passage to the fuel injection hole 151. The fuel valve needle 152 has an injection pipe 1 at its axial center.
A fuel passage hole 152a communicating with the injection pipe 14 is formed and opened by pressure oil from the injection pipe 14.

Reference numeral 157 denotes an outer cylinder in which a retaining portion 159 is formed to accommodate water or a mixed oil of water and oil. A nozzle hole 242 is opened in the outer cylinder 157 forming the stop portion 159 so that the spray is injected near the outside of the fuel nozzle hole 151 on the injection axis.

156 is a passage that communicates the retaining portion 159 and the injection hole 242, and 158 is an on-off valve that opens and closes the passage.

The retaining portion 159 is a passage 2 for water or mixed oil.
It communicates with the communication pipe 25 via 41, and a control valve 24 is provided in the middle thereof. The control valve 24 is controlled to open and close in accordance with the lift timing of the fuel valve needle 152.

158 is a stop part 159, a passage 156 and a nozzle hole 2
A valve that opens and closes between 42 and 160 is an open/close valve 15.
8 return spring, 157 has a plurality of nozzle holes 24 at the tip.
The outer cylinder 161 in which 2 is formed is formed between the outer periphery of the on-off valve 158 and the inner periphery of the outer cylinder 157, and is a chamber in which water or a mixed oil of oil is stored. The on-off valve 158 is operated by the fluid pressure in the reservoir 159 that returns to the spring 1.
It automatically opens when it overcomes the elasticity of 60 degrees.

In FIG. 2, 21 is a high pressure pump, 22, 2
3 is a heater; water or mixed oil sent from the high-pressure pump 21 is heated by heaters 22 and 23 to become high-temperature, high-pressure water or mixed oil, and introduced into the communication pipe 25.

The rest is the same as the conventional example shown in FIG. 1, and the same parts are given the same reference numerals.

Next, the operation of the above embodiment will be explained.

FIG. 3 shows details of a fuel injection valve that injects fuel oil and water or a mixed oil, and is composed of two systems: a fuel system and a water or mixed oil system.
The high-pressure fuel that reaches the fuel injection hole 151 from the injection pipe 14 through the fuel passage hole 152a of the fuel valve needle 152 and the fuel oil passage 153 flows through the fuel valve needle 15.
2, the injection is automatically controlled.

On the other hand, as shown in FIG. 2, water or mixed oil pressurized by the high-pressure pump 21 is heated by heaters 22 and 23, enters the injection valve 15 through the control valve 24, and flows through the chamber 161 and the passage 241. Through the reservoir part 159
When the on-off valve 158 is opened, the fuel is injected from the injection hole 242 through the passage 156. At about the same time, the high pressure fuel reaches the passage 153 due to the opening of the fuel valve needle 152. Therefore, almost simultaneously, fuel is injected from the fuel valve injection hole 151 and water or mixed oil is injected from the injection hole 242.

As a result, the fuel receives heat from the water or mixed oil, and atomization is promoted by the high-speed flow.
Furthermore, by increasing the ejection energy, the penetration force also increases, and mixing with the air in the combustion chamber becomes better.

〔Effect of the invention〕

As mentioned above, the fuel injection valve of the present invention simultaneously injects high-temperature, high-pressure water or mixed oil toward the fuel oil injected from the injection valve, which promotes atomization of the fuel and slows down the movement of the spray. Furthermore, by increasing the ejection energy, the penetration force also increases, and the formation of the air-fuel mixture becomes better, which has a great effect of improving combustion.

Further, since the fuel flows in direct current through the fuel passage hole in the fuel valve needle to the fuel injection hole, the fuel does not pass through sliding parts or seal parts and does not mix with other fluids.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a combustion system of a conventional diesel engine, FIG. 2 is a diagram of the combustion system of the present invention, and FIG. 3 is a detailed sectional view of a fuel injection valve according to the present invention. 13... Fuel injection pump, 14... Injection pipe, 1
5...Fuel injection valve, 151...Fuel oil nozzle hole, 1
56...Passage, 157...Outer cylinder of fuel injection valve, 1
59... Reservoir, 242... Nozzle hole for water or a mixture of water and oil.

Claims (1)

[Claims] 1 Fuel oil with a fuel injection hole 151 drilled at the tip and communicating with the injection hole at the shaft center for injecting high-pressure fuel oil that is intermittently pumped from a fuel injection pump through an injection pipe into the cylinder of the engine. In a fuel injection valve having a nozzle 162 provided with a passage 153, the nozzle is slidably fitted into the nozzle, and a fuel passage hole 152a is bored in the shaft center to open and close the fuel oil passage 153 of the nozzle. A fuel valve needle 152, a reservoir 159 formed in the outer cylinder 157 of the injection valve to be blocked from the fuel oil passage 153 and containing water or a mixed oil of water and oil, and a reservoir 159 formed in the outer cylinder to accommodate water or a mixed oil of water or oil. The nozzle includes a nozzle hole 242 that injects a mixture of water and oil, and an on-off valve 158 that automatically opens and closes between the nozzle hole and the reservoir by the pressure of the water or the water and oil mixture. A fuel injection valve characterized in that a flow path to the fuel injection hole 151 and a flow path to the injection hole 242 of the outer cylinder are configured as separate flow paths that are cut off from each other.