JPS59126021A - Filter regenerating apparatus ror internal-combustion engine - Google Patents

Abstract

PURPOSE:To regenerate a filter efficiently by an inexpensive apparatus, by producing microwaves while supplying a part of exhaust gas to the filter in regenerating a filter disposed in an exhaust system. CONSTITUTION:Exhaust gas discharged from an engine 1 is carried to a filter 5 via an exhaust branch pipe 3a, and after particulates contained in the exhaust gas are captured and removed by the filter 5, it is discharged to the atmosphere via a muffler 13. In regenerating the filter 5 when it has caused clogging, a solenoid valve 15 is opened to carry most of the exhaust gas to the muffler 13 via a branch pipe 3b. At the same time, a part of exhaust gas is carried toward the filter via the branch pipe 3a by the pressure loss produced by a pressure- loss member 14. With such an arrangement, the filter 5 is regenerated by heating and burning only the particulates contained in the exhaust gas by the function of microwaves produced through operation of a microwave oscillator 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Detailed description of the invention]
The present invention relates to a filter regeneration device for an internal combustion engine that removes ticumte.

Conventionally, various devices of this type have been studied, one of which is shown in FIG. 1. In Fig. 1, 1 is a diesel engine, 2 is an air manifold attached to the diesel engine 1, 3 is an exhaust pipe connected to the exhaust manifold 2, and 4 is a filter storage device installed in the middle of the exhaust pipe 3. It constitutes a part of the exhaust pipe 3. 5 is a filter housed in the filter housing 4; 9 is a filter regeneration burner f' provided in the exhaust pipe 3 between the exhaust manifold 2 and the filter housing 4; 1;
0 is a fuel pump that supplies fuel to the filter regeneration burner 9, and 11 is an air pump that supplies all of the combustion air to the filter regeneration burner 9.

The operation of the above conventional device will be explained. diesel engine 1
Particulates in the exhaust gas discharged by the exhaust gas pass through the exhaust manifold 2 and the exhaust pipe 3, and are filtered by the filter 5 housed in the filter housing 4, where they are accumulated in the filter 5. When particulates accumulate in the filter 5 to a certain extent, the pressure in the exhaust manifold 2 increases and the fuel efficiency of the diesel engine 1 deteriorates, so in this case, the filter 5 must be completely regenerated.

Generally, the main constituent of particulates is carbon No. 1, and its ignition temperature J'' is around 1500°C.

Therefore, if the temperature of the filter 5 in which particulates have been accumulated is raised to y]1-500° C. or higher by some method, the particulates will be burned off and the filter 5 can be regenerated. In the case of FIG. 1, fuel is combusted in the burner 9, the combustion exhaust gas is mixed with the engine exhaust gas, and the temperature of the engine exhaust gas is raised to 500°C or more, thereby indirectly raising the temperature of the filter 5. Play step 5.

That is, fuel f' supplied by the fuel pump 10 and f' supplied by the air pump 11 are mixed and combusted in the combustion air chamber burner 9 to create a high-temperature combustion exhaust gas system.
The filter 5 is regenerated by feeding it into the engine exhaust gas in the exhaust pipe 3.

However, the above device had the following drawbacks. (
1) High pressure that can overcome exhaust pressure (usually 0.8~/
Since the air pump 11 and the fuel pump 10' have large flow rates (usually 100 t/- or more) and large flow rates (usually 100 t/- or more), the devices are large, require a large amount of electricity, and are expensive. (2) Since the exhaust pressure fluctuates depending on the operating state of the engine, it is necessary to control the air pressure and fuel pressure, which is troublesome. (3)
Combustion within the burner 9 was unstable due to fluctuations in exhaust pressure, and it was difficult to regenerate the filter 5 in a stable manner.

This invention was made to eliminate the above-mentioned conventional drawbacks, and the exhaust pipe of an internal combustion engine is branched into two, and one exhaust gas passage is equipped with a microwave reflector, a particulate filter, and a A suitable pressure loss body and an ON-OFF solenoid valve are provided in the other exhaust gas passage, and the one exhaust gas passage is arranged in a manner that bypasses the bibulous filter in the other exhaust gas passage. A microwave supply path is provided in the storage case, and microwaves are supplied from a microwave oscillator to selectively heat and burn the particulates attached to the particulate filter, and the engine An object of the present invention is to provide a filter regeneration device for an internal combustion engine that is less affected by operating conditions and can regenerate a filter stably and efficiently.Embodiments of the present invention will now be described with reference to all the drawings.

In Fig. 2, 3a and 3b are exhaust branch pipes in which the exhaust pipe 3 is branched into two, and one exhaust branch pipe 3a has a filter 5.
A filter storage container 4 containing a filter is provided. 7 #i A microwave supply path consisting of a waveguide branched to the filter housing 4 which is a part of the exhaust branch pipe 3a; 8 is a microwave oscillator attached to the microwave supply path 7, for example. It consists of a magnetron, etc. 12 is a microwave oscillator 8
6 is a microwave reflector provided in the exhaust branch W3a on the outlet side and the population side in order to confine the microwave in the filter housing 4; 15 is a microwave reflector provided in the exhaust branch pipe 3b; TAON-OF
A solenoid valve 14 having the F function is a pressure drop body that provides an appropriate pressure drop to the exhaust gas flowing through the exhaust branch pipe 3b, and 1311 is a muffler provided in the exhaust pipe 3 after the exhaust branch pipes 3a and 3b join together.

In the above device, when it becomes necessary to regenerate the 5 filters, the solenoid valve 15 is first opened, and most of the exhaust gas emitted from the engine 1 bypasses the filter housing 4 and is exhausted from the exhaust branch pipe 3b through the muffler 13. to be done.

At this time, a portion of the exhaust gas flows into the filter housing 4 due to the pressure loss caused by the pressure loss body 14.

Next, microwave power is supplied from the microwave oscillator 8 to the filter housing 4 via the microwave supply path 7 . The microwave reflecting plate 6 is made of, for example, a metal mesh or a cross-shaped metal plate, and reflects microwave-type chips, but fluids such as air and exhaust gas can pass through it without pressure loss. Therefore, the supplied microwave power exists only within the filter housing 4. On the other hand, oxygen necessary for oxidizing particulates is supplied from the exhaust gas flowing throughout the filter housing 4. Due to the nature of microwaves, the microwave power inside the filter housing 4 is absorbed only by the particulates deposited on the filter 5.
Each batch is selectively heated. In this way, the particulates are heated above their ignition point, oxidized and burned, and the filter 5 is regenerated. When the regeneration is completed, the solenoid valve 15 is closed, and the exhaust gas from the engine 1 follows only the exhaust gas branch pipe 3a and is discharged from the muffler 3. This state continues until the next regeneration is performed, and the particulates in the exhaust gas are removed. is deposited on the filter 5 and removed from the exhaust gas.

3 and 4 are the second and third embodiments of this embodiment, respectively. In the case of Fig. 3, it is attached to the engine l.
The microwave power source 12 is driven by the AC output of the fc alternator 20, and in the case of FIG. 4, the AC output of the alternator 20 or the DC output of the battery 21? Invar 22? The AC output is added to all the microwave power sources 12 converted through the converter, and the power source configuration can be simplified in any n example.

Incidentally, in each of the above embodiments, a case is shown in which a metal waveguide is used as the microwave supply path 7, but a coaxial cable which can be bent freely may also be used. Further, it is not necessary to completely align the axes of the microwave supply path 7 and the filter 5, but it is possible to arrange the filter 5 and the microwave supply path 7 so that they are effectively sandwiched between the two microwave reflection plates 6. Good. Further, when the engine is a gasoline engine, the combustion is performed at a leaner than stoichiometric mixture ratio when the filter 5 is regenerated, which has the same effect as the above embodiment.

As described above, in the present invention, KFi during filter regeneration
Part of the engine exhaust gas is supplied to the filter, and microwave power is supplied only to the filter, and this microwave power selectively heats and burns off all the particulates that have accumulated on the filter. It does not require a high-pressure, large-flow air pump or fuel pump, and the device is small and does not require electrical input, making it inexpensive. There is no need to control the air pressure or fuel pressure of the pump, and the filter can be regenerated stably and efficiently without being affected by engine operating conditions.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional device, and FIGS. 2 to 4 are block diagrams of first to third embodiments of the device of the present invention, respectively. DESCRIPTION OF SYMBOLS 1...Diesel engine, 2...Exhaust 7 manifold, 3...Exhaust pipe, 3a, 3b...Exhaust branch pipe,
4... Filter storage container, 5... Filter, 6...
Microwave reflector, 7--Microwave supply path, 8...
・Microwave oscillator, 12...Microwave power supply, 13
... muffler, 14 ... pressure loss body, 15 ... solenoid valve,
2o... Alternator, 21... Battery, 22
...Inverter. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno - 1. Indication of the case: Japanese Patent Application No. 1363/1988 29 Name of the invention Filter regeneration device for internal combustion engine 3 Person making the amendment Representative: Hitoshi Katayama Department 4: Agent 5: Details subject to amendment Column for detailed explanation of the invention in the book - 6, Contents of amendment, page 4, line 16, 17) r O,8sy/-JJ?
Correct as r O, 8Kf/cJJ.

Claims (4)

[Claims] (1) The exhaust pipe of the internal combustion engine is branched and merged with the muffler, and one exhaust branch pipe is equipped with a filter that removes all particulates from the exhaust gas, and a microwave that is driven by a microwave power source to generate microwave sound. In addition to providing an oscillator, a microwave reflector plate that allows exhaust gas to flow back and reflects microwave sound is provided on the upstream and downstream sides of the filter and microwave oscillator installation position in one exhaust branch pipe, respectively, and in the other exhaust branch pipe. An internal combustion engine characterized in that the pipe is provided with a valve mechanism for opening and closing the pipe and a pressure loss body that allows a part of the exhaust gas to flow to the other exhaust branch pipe when the valve mechanism opens, that is, when the filter is regenerated. Engine filter regeneration device. (2) A filter regeneration device for an internal combustion engine according to claim 1, wherein the microwave reflecting plate is formed of a metal mesh or a cross-shaped metal plate. (3) If the internal combustion engine is a gas engine, the internal combustion engine is operated at an air-fuel ratio thinner than the stoichiometric mixture ratio during filter regeneration. The filter regeneration device for an internal combustion engine as described in . (4) The alternator's alternator's AC power of the microwave power supply that drives the microwave oscillator is characterized by being obtained from the AC output that is partially converted to AC, in contrast to the DC output of the power source. Claims 1-
The filter regeneration device for an internal combustion engine according to item f'L751 of Item 3.