JPH07150965A - Dual fluid injection device - Google Patents

Abstract

PURPOSE:To reduce thermal stress of an engine while reducing NOX by opening a control valve during a term except a fuel infection term so as to infect water from a second nozzle hole toward a high temperature part, by means of a control device controlling to open/close the control valve opening/closing a water passage. CONSTITUTION:Opening/closing signals are transmitted to a control valve 15 controlling to open/close a water feed pipe 14 through a circuit 23 from a control device 19. The control device 19 opens the control valve 15 after a certain term since the lapse of a fuel injection term, water increasing the pressure by a pump 17 and of a quantity to be discharged at one injection passes through a water passage 20 so as to push a check valve open and enter a second fuel pocket 10, and pushes a second needle valve 9 open so as to inject water from a second nozzle hole 8 toward the high temperature part in a combustion chamber. Hereby, temperature of the wall part of the combustion chamber is lowered, thermal load of it is reduced, and a high power engine can be obtained while NOX can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-fluid injection device for an internal combustion engine which reduces nitrogen oxides (NOx) in exhaust gas by injecting fuel and water from a single injection valve into a combustion chamber. .

[0002]

2. Description of the Related Art In an internal combustion engine, particularly a diesel engine, as a means for reducing nitrogen oxides (NOx) in exhaust gas, a two-fluid (fuel-water) which injects fuel and water into a cylinder at appropriate timing. Injection devices are being put to practical use.

One of the two-kind fluid ejecting apparatus according to FIG.
An example of an injection valve that injects fuel and water from each injection valve is shown. In the figure, 1 is an injection valve main body, and a fuel passage 21 and a water passage 20 are bored in the main body 1. 4 is a nozzle tip, 5 is a fuel injection port, 6 is a needle valve, 12 is a needle valve spring for setting the valve opening pressure of the needle valve 6, 7 is a fuel reservoir, and in the fuel reservoir 7, a fuel passage and a water passage 20 are provided. Have joined. A check valve 11 is provided in the water passage 20, and is configured to allow only the flow of water to the fuel reservoir 7 side.

In the injection valve constructed as described above,
The fuel pressure-fed from the fuel injection pump (not shown) reaches the fuel reservoir 7 through the fuel passage 21. On the other hand, when the control valve (not shown) provided in the water supply path is opened, the water pumped by the water supply pump (not shown) reaches the fuel pool 7 through the water passage 20.

The pressure in the fuel sump 7 is the needle valve spring 12
When the valve opening pressure set at is exceeded, the needle valve 6 is opened, and fuel and water are injected into the combustion chamber 30 at an appropriate timing and in an appropriate amount.

[0006]

However, the conventional two-kind fluid injection device is mounted for the purpose of reducing the pollution of the engine, that is, reducing nitrogen oxides (NOx), and the fuel chamber 30 The water injected inside could not be used for cooling the wall of the combustion chamber.

An object of the present invention is to use the water injected from the injection valve into the combustion chamber to cool the constituent members of the combustion chamber, thereby reducing NOx and reducing the thermal stress of the engine to achieve high output and low NOx. To provide the engine.

[0008]

In order to solve the above problems, the present invention provides a fuel supplied through a fuel injection pipe and water supplied through a water supply pipe into a combustion chamber from a single injection valve. In an internal combustion engine provided with a two-fluid injection system for injecting, a first fuel passage and a second fuel passage communicated with the injection pipe, and a fuel stored in the first fuel passage is stored in the injection valve. The fuel reservoir, a second fuel reservoir in which the fuel that has passed through the second fuel passage and the water that has passed through the water passage merge, and the first fuel reservoir
First opening / closing between the fuel reservoir and the first injection port for fuel injection
A needle valve, a second injection port that opens toward a high temperature portion of the combustion chamber such as an exhaust valve, and a second needle valve that opens and closes between the second fuel reservoir and the second needle valve are provided, and the water passage is provided. A control device that controls the opening and closing of a control valve that opens and closes the control valve is opened during a period other than the fuel injection period to inject the water from the second injection port toward the high temperature portion. Is characterized by.

[0009]

The fuel pressure-fed by the fuel injection pump is injected into the combustion chamber by the opening of the first needle valve and is used for combustion.
A part of it reaches the second fuel pool through the second fuel passage.

On the other hand, when the control valve of the water supply path is opened during a period other than the fuel injection period, the amount of water that can be discharged by one injection is sent to the second fuel reservoir, and the second needle valve By opening the valve, the fuel is injected toward a high temperature part such as an exhaust valve in the combustion chamber, and this part is cooled. As a result, the temperature of the constituent members of the combustion chamber is lowered, thermal stress is reduced, and NOx is also reduced by water injection.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the figure, 40 is an injection valve, 4 is a nozzle tip of the injection valve 40, 1 is a fuel tank, 18 is a water tank, 2 is a fuel pump, 41 is a fuel injection pump, 3 is a fuel injection pipe, 17 is a water supply pump, 14 and 16 are water supply pipes,
Reference numeral 61 denotes a fuel supply pipe, the fuel in the fuel tank 1 is supplied to the injection valve 40 via the fuel supply pipe 61 and the fuel injection pipe 3, and the water in the water tank 18 is supplied to the water supply pipe 14. Have been supplied through.

Reference numeral 15 is a control valve for controlling the opening / closing of the water supply pipe 14, and 19 is a line 23 for sending an opening / closing control signal to the control valve 15.
It is a control device that transmits via the. The control device 19 receives a detection signal of the engine operating state such as the engine speed and load, and controls the injection timing and injection amount of water to be supplied to the injection valve 40 based on the detection signal. Further, in FIG. 3, 50 is an exhaust valve, 50a is an umbrella portion of the exhaust valve, 53 is a cylinder liner, 52 is a cylinder head, and 51 is a piston.

FIG. 2 is a detailed cross-sectional view of the injection valve 40. Reference numeral 21 is a first fuel passage communicating with the fuel injection pipe 3, and the lower end of the first fuel passage 21 is in the first fuel reservoir 7. It is open. 5 is the first injection port for fuel injection, 6 is the first injection port
A first needle valve that opens and closes between the injection port 5 and the first fuel sump 7, 1
3 is a spring for the first needle valve.

Reference numeral 10 is a second fuel pool formed below the first fuel pool 7, and 8 is a second fuel pool formed toward the high temperature portion such as the umbrella portion 50a of the exhaust valve 50 and the edge of the start valve hole. It is 2 nozzles. A second fuel passage 22 branched from the fuel injection pipe 3 and a water passage 20 communicating with the water supply pipe 14 are opened in the second fuel pool 10 so that fuel and water can join. ing.

Reference numeral 11 is a check valve provided in the water passage 20,
Only the flow of water toward the second fuel pool 10 is allowed. Reference numeral 6 denotes a second needle valve that opens and closes between the second fuel reservoir 10 and the second injection port 8, and is slidably fitted on the inner circumference of the first needle valve 6. Reference numeral 12 is a spring for the second needle valve.

In the engine equipped with the two-kind fluid injection device constructed as described above, the high-pressure fuel pumped from the fuel injection pump 41 at an appropriate timing reaches the first fuel reservoir 7 through the first fuel passage 21. , The first needle valve 9 is pushed up and opened to be injected from the first injection port into the combustion chamber 30.

At this time, a part of the fuel having passed through the second fuel passage 22 reaches the second fuel reservoir 10, pushes the second needle valve 9 open, and is injected into the combustion chamber 30 from the second injection port.

When the control valve 15 is opened after a lapse of a certain period after the fuel injection period has elapsed, the amount of water that is discharged by one injection pressurized by the water supply pump 17 becomes water. Passage 2
The check valve is pushed open through 0 to enter the second fuel reservoir 10 and the second needle valve 9 is pushed open to open the exhaust valve umbrella portion 50 in the combustion chamber 30.
It is injected toward a high temperature portion such as a and the edge portion (not shown) of the starting valve hole.

As a result, the temperature of the wall of the combustion chamber 30 is lowered, the heat load on the wall is reduced, and the NOx reduction effect can be obtained as in the conventional fuel-water injection engine.

[0020]

As described above, according to the present invention, since the water is injected toward the high temperature portion of the combustion chamber, the NOx reduction effect by the water injection can be obtained at the same time as the conventional one. The temperature of the combustion chamber wall can be reduced, and the heat load on the combustion chamber wall can be reduced. This makes it possible to obtain a high-power engine with low NOx.

[Brief description of drawings]

FIG. 1 is a configuration diagram (system diagram) of a two-fluid ejection device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the same injection valve.

FIG. 3 is a sectional view of the vicinity of the combustion chamber.

FIG. 4 is a response diagram of FIG. 1 showing a conventional example.

[Explanation of symbols]

1 ... Fuel tank, 3 ... Fuel injection pipe, 5 ... First injection port, 6 ...
1st needle valve, 7 ... 1st fuel reservoir, 8 ... 2nd injection port, 9 ... 2nd
Needle valve, 10 ... Second fuel reservoir, 11 ... Check valve, 14 ... Water supply pipe, 15 ... Control valve, 18 ... Water tank, 19 ... Control device, 20 ... Water passage, 21 ... First fuel passage, 22 …
Second fuel passage, 30 ... Combustion chamber, 40 ... Injection valve, 50 ... Exhaust valve.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02M 43/04 61/10 A

Claims (1)

[Claims] 1. A combustion chamber from a single injection valve for fuel pressure-fed from a fuel injection pump and water fed from a water supply pump through a water supply pipe having a control valve for passage area control. In an internal combustion engine including a two-kind fluid injection device configured to inject fuel into a fuel cell, the injection valve stores a first fuel passage communicating with the injection pipe, and fuel that has passed through the first fuel passage is stored. A first fuel reservoir, a first needle valve that opens and closes between the first fuel reservoir and a first injection port for fuel injection, a water passage communicating with the water supply pipe, and a branch from the first fuel passage A second fuel pool in which the separated second fuel passage and the water passage merge, and the second fuel reservoir provided in the water passage.
When provided with a check valve that allows only the flow of water toward the fuel reservoir side, the second injection port directed to the high temperature portion of the combustion chamber, such as an exhaust valve, is provided concentrically with the first needle valve. A second needle valve that opens and closes between the second fuel reservoir and the second injection port, and the control valve is opened during a period other than the fuel injection period to allow the water to pass through the water passage and the second fuel reservoir. A two-kind fluid ejecting device comprising a control device for ejecting from the second ejection port toward the high temperature portion.