JP2637600B2 - Two-fluid injection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a two-fluid injection fuel valve applied to fuel injection of a diesel engine.

[Prior art] Diesel engines are widely used as prime movers due to their high thermal efficiency, but their exhaust components are harmful to CO, CO ₂ , HC, NO
_A major problem was that _{x and the} like were contained in large amounts.
Therefore, a fuel valve that adds water to fuel and injects the fuel in order to reduce NO _x will be described.

With reference to FIG. 6, a conventional fuel valve designed to simultaneously inject fuel and water and a system thereof will be described.

In the figure, 1 is a fuel valve body, 2 is a nozzle tip, 3
Denotes an injection hole, and 4 denotes a fuel inlet fitting. 5 is a fuel oil passage in the fuel valve, 6 is a fuel oil passage in the presser foot, 7 is a fuel oil passage in the nozzle tip, 8 is a needle valve sack, 9 is a needle valve, 10 is a needle valve spring receiver, 11
Is a spring, and 12 is a needle valve opening pressure adjusting hardware, which changes the valve opening pressure of the needle valve 9 by changing the installation length of the spring 11. 13 is a water injection fitting, 14 is a ball check valve, 15 is a check valve spring, 16
Is a water passage in the fuel valve, 17 is a water passage in the presser foot, and 18 is a water passage in the nozzle tip. The fuel oil passage 7 in the nozzle tip and the water passage 18 in the nozzle tip join at the needle valve sack 8.

Next, a fuel and water supply system for the fuel valve will be described. 21 is a fuel tank, 22 is a fuel supply pump, 23 is a fuel injection pump main body, 24 is a plunger barrel,
25 is a plunger, 26 is a discharge valve, and 27 is a constant pressure valve. The fuel pump discharge part 26 and the fuel inlet fitting 4 are connected by an injection pipe.

28 is a water tank, 29 is a water supply pump, 30 is a water supply pipe, 31
Is a solenoid valve, and 32 is a water injection pipe, which is connected to the water injection hardware 13. Reference numeral 33 denotes a controller for controlling the opening / closing valve of the solenoid valve 31. The valve opening timing and period are controlled by a signal synchronized with a crankshaft of an engine (not shown).

 Next, the operation of the conventional example will be described.

The fuel supplied from the fuel tank 21 to the fuel injection pump 23 by the fuel supply pump 22 is compressed by the plunger 25, is pressurized, pushes up the discharge valve 26, and is sent from the injection pipe to the fuel valve. The high-pressure fuel guided from the oil passage 5 in the fuel valve, the oil passage 6 in the presser foot, and the oil passage 7 in the nozzle tip to the needle valve sack portion 8 overcomes the spring force of the spring 11 and pushes up the needle valve 9 to raise the injection hole. Fuel is injected from 3.

In the fuel and water injection fuel valve shown here, water is sent to the needle valve sack and the water passage 18 in the nozzle tip at a time other than the fuel injection time to mix and inject the fuel and water.

Next, the method of mixing water in the fuel valve will be described in detail.
The needle valve sack 8 after the injection and the oil passage and the water passage communicating therewith have a residual pressure Pr defined by the equal pressure valve 27 of the fuel injection pump.

On the other hand, the water in the water tank 28 is pressurized by the water supply pump 29 to a pressure higher than the aforementioned residual pressure Pr. When the solenoid valve 31 is opened under the control of the controller 33, the high-pressure water pushes up the check valve 14 from the water supply pipe 32 to the water injection fitting 13 and is injected into the water passage 16 in the fuel valve. At this time, the amount of water to be injected is optimally controlled by the controller 33 by changing the opening time of the solenoid valve 31.

The water injected into the water passage 18 in the nozzle tip and the needle valve sack 8 as described above is appropriately mixed with the fuel, and then the needle valve 9 is pushed up by the high-pressure fuel pressure fed from the above-described fuel injection pump. It is injected from the injection hole 3. At this time, check valve 14
Is closed to prevent fuel from flowing back into the water supply system.

[Problems to be solved by the invention]

Here, it has been described that the fuel injected into the needle valve sack portion and the oil passage in the nozzle tip is appropriately mixed and injected. However, depending on how the water is mixed, only water is first injected and ignition occurs. In some cases, the engine became unstable or could not ignite at all, and the engine stopped.

Therefore, in terms of realizing a reliable ignition, it is necessary to inject the injection the amount of water is effective for NO _x reduction.

An object of the present invention is to solve the above conventional apparatus, is realized reliable ignition while changing the water injection position according to a change in engine load, it is possible to add the water required to reduce且NO _x two-fluid jet In providing the device.

[Means for solving the problem]

A plurality of water inlets to the oil passage in the fuel valve were provided, and the junctions of the water injection passages and the oil passages were different.

In addition, each valve has a solenoid valve for controlling water injection, which operates independently, and optimally controls the amount and location of water injection based on information on the engine speed and fuel pump rack taken into the computer. I did it.

(Operation)

Engine load, i.e., in accordance with the injection amount of the fuel changing the injection place of water, while ensuring a stable ignition, further performs injection optimum amount of water to NO _x reduction.

That is, when the fuel injection amount is small, a small amount of water is required, but when the fuel injection amount is large, the amount of water needs to be increased.

Therefore, when the injection amount is small, a small amount of water is injected into the needle valve sack part, and as the injection amount increases, the injection point is moved to a place away from the needle valve sack part to secure ignition by the initial fuel injection, and then Injection and refueling are performed and the expected NO _x
Achieve low-emission combustion.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a structural diagram of the embodiment, and FIG.
The view from II is shown. FIG. 3 is a sectional view of FIG. 2 (AA), FIG. 4 is a sectional view of FIG. 2 (AB), and FIG. 5 is a sectional view of FIG. 2 (AC). First, the configuration will be described with reference to FIG. (The fuel valve section shows a section taken along the line AA in FIG. 2) 1 is a fuel valve main body, 2 is a nozzle tip, 3 is an injection hole, 4 is a fuel valve inlet fitting, 5 is an oil passage in the fuel valve, and 6 is a presser fitting. Inner oil passage, 7 is an oil passage in the nozzle tip, 8 is a needle valve sack, 9 is a needle valve, 10 is a needle valve spring receiver, 11 is a spring, and 12 is a valve opening pressure adjusting metal of the needle valve and a spring mounting length. By changing the pressure, the valve opening pressure of the needle valve 9 changes. 13a is the first water-injection hardware (the subscript a is the first
14a is a ball check valve, 15a is a check valve spring, 16a is a water passage in the fuel valve, 17a is a water passage in the presser foot, 18a
Is a channel inside the nozzle tip. The fuel oil passage 7 in the nozzle tip and the water passage 18a in the nozzle tip join at the sack portion of the needle valve.

Furthermore, as a system configuration, 21 is a fuel tank, 22
Is a fuel supply pump, 23 is a fuel injection pump, 24 is a plunger barrel, 25 is a plunger, 26 is a discharge valve, and 27 is a constant pressure valve. The fuel pump discharge valve section 26 and the fuel inlet fitting 4 are connected by an injection pipe. 28 is a water tank, 29 is a water supply pump, 30 is a water supply pipe, 31a is a solenoid valve (similarly for 31b and 31c) and 32a is a water injection pipe, which is connected to the water injection hardware 13a. (32b is connected to the water injection fitting 13b shown in FIG. 2, and 32c is similarly connected to 13c.) 33 is a solenoid valve 31a, 31b, 3
A controller that controls the open / close valve of 1c.
Control the timing of the on-off valve and the engine.
The control computer 34 receives a fuel pump rack signal, an engine speed, an engine crank angle signal, and the like.

In FIG. 2, reference numeral 13a denotes a water injection fitting of the first water inlet, 13b denotes a water injection hardware of the second water inlet, and 13c denotes a water injection hardware of the third water inlet.

FIG. 3 shows a cross section of the first water injection passage of the fuel valve portion in FIG. 1 (cross section in FIG. 2 (AA)). The oil passage and the water passage join at the needle valve sack portion.

FIG. 4 shows a cross section of the second water injection passage (cross section in FIG. 2A-B), and the water injection passage 18b in the nozzle tip communicates with the oil passage through 100 communication holes.

FIG. 5 is a cross section of the third water injection channel (FIG. 2 (A-C) cross section).
The presser fitting water passage and the oil passage are communicated with each other by the communication hole 200 on the upper end surface of the nozzle tip.

Although not shown here, communication between the water channel and the oil channel in the top surface of the presser foot or in the fuel valve body is also conceivable.

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

Since the water injection method is shown in the conventional example, here, the operation when the injection amount gradually increases will be described. When the injection amount is small, that is, when the load on the engine is small, only the solenoid valve 31a of the first water inlet shown in FIG. 3 opens and closes, and water is injected into the needle valve sack portion 8.

When the injection amount is slightly increased, the solenoid valve 31a stops operating, and only the valve 31b shown in FIG. 4 starts operating. At this time, the pressure control valve of the fuel injection pump is pushed up and the water is
At the beginning of the injection, the fuel in the lower oil passage and the needle valve sack is injected from the communication hole 100 at the beginning of the injection, then the mixture of water and fuel, and finally the fuel is injected. Is done.

When the injection amount further increases, only 31c shown in FIG. 5 is activated, and water is injected into the oil passage above the communication hole 200. At this time, the injection amount of water is also quite large,
Since the initial injection amount also increases from the communication hole 200 to the lower volume, combustion is not stopped.

The selection of the operation of each solenoid valve and the setting of the operation period are optimally controlled by a preset program on the basis of information such as the engine speed and the fuel pump rack which are taken into the computer 34.

〔The invention's effect〕

The present invention consists, as said, by changing the position of injection water in accordance with the change of the injection quantity of fuel, in terms of realizing a reliable ignition, it is possible to add the water required for NO _x reduction.

Therefore, it is possible to provide an engine that can operate stably and has a low emission amount.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram according to a first embodiment of the present invention,
FIG. 2 is a top view of the fuel valve of the present invention (viewed from arrow II in FIG. 1), and FIG.
FIG. 4 is a sectional view of the fuel injection valve according to the first embodiment of the present invention (section AA in FIG. 2), FIG. 4 is a sectional view of the second injection path of the fuel valve of the present invention (section A-B in FIG. 2), and FIG. FIG. 6 is a fuel valve and system diagram showing a conventional two-fluid injection device according to the present invention. 1 ... fuel valve body, 6 ... oil passage, 18a, 18b, 18c ... water injection passage, 31a, 31b, 31c ... solenoid valve, 33 ... controller

Claims (2)

(57) [Claims] In a two-fluid injection device for mixing and injecting fuel and water, a plurality of water injection paths are provided, and the water injection path is communicated with a part different from an oil path to which fuel is supplied. A two-fluid ejection device characterized by the above-mentioned. 2. An electromagnetic valve for opening and closing a water injection path is provided in each of the injection paths, and the operation valve of the engine is inputted, and as the fuel injection amount increases, the electromagnetic valve of the water injection path communicates with the upstream side of the oil path. A control means for opening the first member is provided.
Item 2. The two-fluid ejection device according to Item 1.