JPH03279660A - Nox reducing device of type burnt gas is supplied into combustion chamber of engine - Google Patents

Abstract

PURPOSE:To enhance combustion performance, and to contrive the reduction in fuel consumption by controlledly operating a volume-changing means by a gas supply/exhaust control device, so that the gas inside a combustion chamber can be sucked in a gas supply/exhaust chamber by the operation of the volume-changing means. CONSTITUTION:An engine is provided with a gas supply/exhaust operating device 1 and a gas supply/exhaust control device 2. A gas supply/exhaust chamber 3 is communicated with the combustion chamber 5 of an engine, and a volume-changing means 4 is controlledly operated by the gas supply/exhaust control device 2 so as to synchronize with the crankshaft of the engine. The gas supply/exhaust control device 2 operates the volume-changing means 4 so as to increase the volume of the gas supply/exhaust chamber 3 for sucking the gas in the combustion chamber 3 in it. Thus, combustion performance can be enhanced, and the reduction in fuel consumption can be contrived.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a combustion gas supply type N to the combustion chamber of an engine.
This invention relates to an Ox reduction device.

[Prior Art] Some conventional NOx reduction devices that supply burned gas to the combustion chamber of an engine are based on an exhaust gas recirculation system.

This conventional device supplies the exhaust gas in the exhaust pipe to the intake air in the intake pipe to lower the maximum combustion temperature.

[Problem to be solved by the invention] However, the prior art mentioned above has the following problems (1) and (2).

■Since exhaust gas is supplied to the intake air flowing into the combustion chamber, the exhaust gas is dispersed throughout the combustion chamber, making it impossible to effectively lower the maximum combustion temperature, resulting in a low NOx reduction rate.

In other words, the highest combustion temperature occurs near the center of the combustion chamber, where there is less heat loss to the cylinder wall, but since the exhaust gas is dispersed throughout the combustion chamber, the amount of exhaust gas supplied to the center of the combustion chamber is reduced. This is not achieved sufficiently, and the maximum combustion temperature cannot be effectively reduced.

■Since exhaust gas is supplied to the combustion chamber, combustion performance is reduced and fuel efficiency is high.

The present invention aims to supply a sufficient amount of burned gas to a central location in a combustion chamber where the highest combustion temperature occurs;
The problem is to prevent combustion performance from deteriorating even though burned gas is supplied to the combustion chamber.

[Means for Solving the Problems] The present invention provides a combustion gas supply type NO
The x reduction device is characterized by being configured as follows.

For example, as shown in FIGS. 1 and 2, a gas supply/discharge operating device 1 and a gas supply/discharge control device 2 are attached to the engine, and the gas supply/discharge operating device 1 adjusts the volume of the gas supply/discharge chamber 3 to the volume. The gas supply and discharge chamber 3 is configured to be changeable by a change means 4, and the gas supply and discharge chamber 3 is communicated with the combustion chamber 5 of the engine, and the volume change means 4 is controlled and operated by the gas supply and discharge control device 2 in synchronization with the crankshaft of the engine. The gas supply/exhaust control device 2 controls the volume changing means 4 at the gas discharge timing X set within the pressure increase period B from the intake end timing a of the combustion chamber 5 to before the combustion chamber pressure peak timing. While the volume reduction operation is performed to discharge the combusted gas in the gas supply/discharge chamber 3 into the combustion chamber 5, the gas suction timing Y is set at E between the end of the gas discharge timing X and the exhaust end timing d. In, the volume changing means 4
The gas in the combustion chamber 5 is sucked into the gas supply/discharge chamber 3 by expanding the volume of the combustion chamber 5.

Engines to which this invention is applied include diesel engines,
It can be any of the Kallin engines.

A specific example of the volume changing means 4 for changing the volume of the gas supply/discharge chamber 3 is one using a plunger 6 or a diaphragm, and its driving means is an electromagnetic drive device equipped with an electromagnetic solenoid 7. , a hydraulic drive device equipped with a hydraulic pump, and a transmission drive device that extracts and transmits power from a crankshaft.

As a specific example of the gas supply/exhaust control device 2 that controls and operates the volume changing means 4 in synchronization with the crankshaft of the engine, for an electromagnetic drive device or a hydraulic drive device, based on detection of the crank angle, As for the timed start control device 8 that starts the drive device in a timed manner and the transmission drive device, a timed transmission mechanism that starts the drive device in a timed manner can be mentioned.

The gas discharge timing X may be set within the pressure increase period B from the intake end timing a of the combustion chamber 5 to before the combustion chamber pressure peak timing, that is, before or after the combustion start timing f. If it is set before the start time f, the burned residue in the gas supply and discharge chamber 3 will be discharged into the intake air in the combustion chamber 5, and if it is set after the combustion start time f, the burned residue in the gas supply and discharge chamber 3 will be discharged. The gas is discharged into the combustion gas in the combustion chamber 5.

The gas suction time Y is a period from the end of the gas discharge time X to the exhaust end time d, that is, before the combustion start time f,
It may be set either within the combustion period F or after the end of the combustion period F. If it is set before the combustion start time f, the gas sucked into the gas supply and exhaust chamber 3 becomes intake air before combustion, and it is set within the combustion period F. Then, the gas sucked in becomes combustion gas, and if it is set after the combustion period F ends, the gas sucked in becomes burnt gas. The intake air sucked into the gas supply and exhaust chamber 3 before combustion is consumed by combustion after being mixed with high-pressure combustion gas that flows into the gas supply and discharge chamber 3 after combustion starts, and the inside of the gas supply and discharge chamber 3 is filled with burned gas. replaced by

Further, the combustion gas sucked into the gas supply/discharge chamber 3 during combustion continues to burn after that and becomes a burned gas.

Therefore, in either case, burned gas can be secured in the supply/discharge chamber 3.

[Effect Co. The present invention provides the following effects (1) and (2).

■The maximum combustion temperature can be effectively lowered because the burned gas can be locally concentrated and supplied to the central part of the combustion chamber where the maximum combustion temperature occurs, immediately before combustion and during the corresponding pressure rise period. I can do it.

Therefore, compared to the conventional exhaust gas recirculation system in which exhaust gas is dispersed throughout the combustion chamber, the NOx reduction rate can be improved.

■Since the combusted gas is discharged into the combustion chamber immediately before combustion and within the corresponding pressure rise period during combustion, this combusted gas can stir the inside of the combustion chamber to improve combustion performance and also to supply combusted gas. Regardless, the combustion performance will not be degraded.

This improves combustion performance and reduces fuel consumption compared to the conventional exhaust gas recirculation system, which only reduces combustion performance with exhaust gas and leaves no room for improvement. .

[Example] Embodiments of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 9 indicates a combustion device for a direct injection type diesel engine.

In this combustion device 9, a cylinder head 11 is assembled on a cylinder block 10, a toroidal combustion chamber 5 is formed on the upper surface of a piston head 13 fitted inside a cylinder 12 of a cylinder block 10, and fuel is supplied into the combustion chamber 5. Injection nozzle 1
It is composed with 5 facing.

The cylinder head 11 is equipped with a combustion flow gas supply type N◯8 reduction device 16, and this device 16 consists of a gas supply/discharge operating device 1 and a gas supply/discharge control device 2.

The gas supply/discharge actuating device 1 has a gas supply/discharge chamber 3 vertically formed in the wall of the cylinder rad 11, a plunger 6 inserted through the upper opening 18 of the gas supply/discharge chamber 3, and an electromagnetic It is configured such that the volume of the gas supply/discharge chamber 3 can be changed by driving the solenoid 7 up and down.

A gas supply/discharge port 19 is opened at the lower end of the gas supply/discharge chamber 3, and the gas supply/discharge port 19 is placed near the center of the fuel chamber 5.
The gas supply and discharge chamber 3 is communicated with the combustion chamber 5 of the engine.

The electromagnetic solenoid 7 is linked to a timed start control device 8 that starts the electromagnetic solenoid 7 in a timed manner based on detection of the crank angle.The plunger 6 is connected to the engine crankshaft (not shown) by the timed start control device 8. It is configured to perform controlled operations in synchronization.

The gas supply/discharge control device 2 is configured to time-control the plunger 6 as follows.

That is, as shown in FIG. 2, at the gas discharge time X, which is set after the combustion start time f and before the combustion chamber pressure peak time, the plunger 6 is operated to reduce the volume, and the combustion in the gas supply and discharge chamber 3 is reduced. While the burned gas is discharged into the combustion chamber 5, the plunger 6 is operated to expand the volume at a gas suction timing Y set in the middle of the exhaust period, and the burned gas in the combustion chamber 5 is discharged into the gas supply/discharge chamber 3. It is designed to be sucked in.

In FIG. 2, the symbol A is the intake period, and the symbol C is the pressure drop period.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams for explaining a combustion gas supply type NOx reduction device according to an embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional view of the surrounding area of the combustion chamber, and Figure 2 is a diagram showing the timing of gas supply and exhaust. FIG. DESCRIPTION OF SYMBOLS 1... Gas supply/discharge operating means, 2... Gas supply/discharge control means, 3...-Gas supply/discharge chamber, 4... Volume changing means, 5...
- Combustion chamber, a... Intake end time, B... Pressure rise period, X... Gas discharge time, d... Exhaust end time, E...
...From the end of X to d, Y...Gas suction time.

Claims (1)

[Claims] 1. A gas supply/discharge operating device 1 and a gas supply/discharge control device 2 are attached to the engine, and the gas supply/discharge operating device 1 changes the volume of the gas supply/discharge chamber 3 using a volume changing means 4. The gas supply and discharge chamber 3 is configured to communicate with the combustion chamber 5 of the engine, and the volume change means 4 is controlled and operated by the gas supply and discharge control device 2 in synchronization with the crankshaft of the engine. The exhaust control device 2 operates the volume change means 4 to reduce the volume at a gas discharge time X set within a pressure increase period B from the intake end time a of the combustion chamber 5 to before the combustion chamber pressure peak time b. , while the combusted gas in the gas supply and exhaust chamber 3 is discharged into the combustion chamber 5, at the gas suction time Y set at E between the end of the gas discharge time X and the exhaust end time d, the volume changing means 4. A NO_x reduction device for supplying burned gas to a combustion chamber of an engine.