JPS60138221A - Diesel particulate reducer - Google Patents

Abstract

PURPOSE:To prevent particulates from sticking to a nearby spot of a fuel injection nozzle and keep off any clogging in the said nozzle hole as well as to improve the reliability, by making an air nozzle hole open in and around a fuel outlet of the fuel injection nozzle, while jetting air from it at all times during engine operation. CONSTITUTION:Exhaust gas inclusive of particulates to be exhausted out of a Diesel engine passes an exhaust pipe 1, running past a trap 3 by way of a combustion chamber 2, and these particulates are collected by the trap 3. When a pressure loss in the trap 3 becomes increased as the amount of collection of particulates grows large, a pressure sensor 4 is set in motion whereby a burner 5 gets operating, thus particulates are burnt up. At this time, fuel out of a fuel pipe 6 is spouted out of a nozzle 11 and mixed with air from an air passage 7 at the combustion chamber 2, thus ignited by a spark plug 8. Air out of an air pipe 9 is always jetted out of an air injection nozzle hole 10 all the time, whereby particulates in and around the nozzle 11 are made so as to be blown off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to the structure of a fuel injection device for suitably regenerating a trap that collects particulates in diesel exhaust.

[Background of the invention]

Conventionally, in order to reduce particulates in the exhaust gas, a trap was installed in the middle of the exhaust pipe to collect the particulates, as described in Japanese Patent Application Laid-open No. 56-56921. A method has been adopted in which a heat source is provided upstream of the trap and the particulates in the trap are regenerated by incineration. However, since the injector is provided in the exhaust gas, this method has the disadvantage that the fuel nozzle of the injector is clogged by particulates in the exhaust gas.

[Purpose of the invention]

The object of the present invention is to provide particulates exposed to exhaust gas,
It is an object of the present invention to provide a highly reliable particulate reduction device that prevents clogging of a nozzle of a fuel injection device for collection trap regeneration.

[Summary of the invention]

Particulates that adhere to the vicinity of the nozzle of the fuel injection device used to regenerate the trap that collects diesel particulates and cause clogging are very fine and mostly dry carbon. Therefore, by injecting air from near the nozzle, this carbon can be blown off and it can be prevented from adhering to the nozzle hole.

[Embodiments of the invention]

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

Exhaust gas containing particulates discharged from a diesel engine passes through an exhaust pipe 1, a combustion chamber 2, and a trap 3. The trap 3 has a ceramic honeycomb structure and collects particulates when the exhaust gas passes through the side wall surface of the cell.

As the amount of trapped particulates increases, the pressure drop in the trap increases, which adversely affects the efficiency and drivability of the diesel engine. Therefore, the pressure loss in the trap is detected by the pressure sensor 4, and when the pressure exceeds a certain value, the burner 5 is activated to incinerate the particulates collected by the filter.

The burner 11 is a pressure spray type (for example, manufactured by Delavan)
The fuel, which has a nozzle 5 and is pumped through the fuel pipe 6, is
A mist is ejected from a very small hole at the tip of the nozzle 5, mixed with the air pumped through the air passage 7 in the combustion chamber 2, and ignited by the spark plug 8.

In a place where exhaust scum is flowing, particulates contained in the exhaust scum are floating in the exhaust pipe and combustion chamber, so
In this method, since the fuel injection port of the nozzle 5 opens into the exhaust pipe, particulates adhere to the fine injection port, causing clogging of the nozzle 5 and poor atomization. In the present invention, by constantly injecting air from the air jet 10 through the air pipe 9, particulates floating near the nozzle 5 are blown away, and the particulates do not adhere to the mouth of the nozzle 1. prevent this and maintain normal operation of the burner.

Air injection during burner operation has the advantage of improving fuel atomization, which also has a positive effect on burner combustion.

〔Effect of the invention〕

According to the present invention, when injecting fuel into the exhaust pipe, the problem of clogging of the nozzle, which was inevitable, can be solved by simply configuring a simple air passage, and at the same time, the atomization of the fuel is improved, and the nozzle It is also effective in cooling the tip, ensuring that the thermal energy necessary for filter regeneration is provided. The technical contribution to the practical application of diesel particulate reduction equipment is extremely significant.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of a diesel particulate reduction device that is an embodiment of the present invention. 1... Exhaust pipe, 2... Combustion chamber, 3... Trap,
4... Pressure sensor, 5... Burner, 6... Fuel pipe, 7... Air passage, 8... Spark plug, 9... Air pipe, 10... Air nozzle, 11... ...Nozzle agent patent attorney Akio Takahashi

Claims (1)

[Claims] 1. A diesel particulate filter that is attached to the exhaust passage of a diesel engine and has a trap that collects particulates in the exhaust gas, and a fuel injection nozzle upstream of the trap to burn the particulates collected in the trap. The curation reduction device is characterized in that an air jet is opened near the fuel outlet of the fuel injection nozzle and air is constantly ejected during operation of the diesel engine, thereby preventing particulates from adhering near the nozzle. Diesel particulate reduction device.