JP2878071B2 - Particulate trap device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate trap device for trapping and removing fine particles contained in exhaust gas of a diesel engine.

[0002]

2. Description of the Related Art There is a particulate trap device in which a plurality of filters for collecting fine particles (particulates) in exhaust gas are installed in an exhaust passage of a diesel engine, and a backwash nozzle is provided downstream of each filter.

[0003] This device has a combustion chamber below the filter, and during regeneration of the filter, closes a valve downstream of the filter so as to prevent exhaust gas from flowing through the filter.
The high-pressure air is blown out from the backwash nozzle, and the trapped particulates are blown down from the corresponding filter into the combustion chamber, and are burned and removed by the electric heater in the combustion chamber. (Japanese Patent Laid-Open No. 2-188613, 3-18609).
No. 4,109,020).

[0004]

However, in such a conventional apparatus, the electric heater in the combustion chamber is always turned on to burn and remove the particulates dropped from the filter. The electric power is large, and particularly when the engine is idling, the amount of power generated by the generator is small, so that a heavy load is imposed on the battery.

An object of the present invention is to solve such a problem.

[0006]

SUMMARY OF THE INVENTION The present invention provides a filter for collecting particulates contained in exhaust gas of an engine.
And a predetermined backwash time from the downstream side during regeneration of the filter
By blowing high-pressure air from the only air reservoir
Blow off the trapped particulates of the filter into the combustion chamber
Means and an electric heater for burning off the particulates
In particulate trap apparatus comprising data and, the, electricity balloon timing of high-pressure air from the air reservoir
Means for turning on the heater for a predetermined operation time ;
Means for detecting the engine speed and the engine speed
When the temperature is below the specified value, the electric heater ON control is forcibly turned off.
And means for performing the same.

[0007]

[0008]

[Function] When a filter is regenerated, a predetermined backwash is performed from the downstream side.
High pressure air from the air reservoir blows out
When the collected particulates of ruta are blown down into the combustion chamber,
At the time of blowing out the high pressure air, the electric heater is turned on.
By the control, the particulates in the combustion chamber are burned and removed.
This electric heater ON control is performed when the engine speed is
If it is less than the value, it is forcibly turned off,
Smell when idling an engine with low power generation
The battery load is temporarily reduced by the operation of the electric heater.
It is possible to prevent the filtration from becoming large .

Further, when the engine speed is lower than a predetermined value, the load on the battery can be further reduced by forcibly turning off the electric heater.

[0010]

FIG. 2 shows an embodiment of the present invention. Reference numeral 10 denotes a trap body installed in an exhaust passage of a diesel engine.

In the trap body 10, the flow path in the body 10 is divided into two systems, and filters 11 and 12 for trapping particulates are interposed in the respective flow paths.

The flow paths 13 on the downstream side of the filters 11 and 12
14 are provided with shutter valves 15 and 16, respectively.

The shutter valves 15 and 16 are provided by the solenoid valve 1.
When the air is sent from the air reservoir 19 when the air valves 7 and 18 are opened, the flow paths 13 and 14 are closed. When the electromagnetic valves 17 and 18 are closed and the air is shut off, the flow paths 13 and 14 are opened. .

The trap body 10 includes filters 11 and 12.
A combustion chamber 20 is formed below the heater, and an electric heater 21 is installed in the combustion chamber 20.

On the downstream side of the filters 11 and 12 of the trap body 10, backwash nozzles 22 and 23 are provided, respectively.

High pressure air from the air reservoir 19 is sent to the backwash nozzles 22 and 23 via solenoid valves 24 and 25, respectively, and when the solenoid valves 24 and 25 are opened, the high pressure air is directed to the filters 11 and 12. It is designed to blow out.

A rotation speed sensor 26 is provided to detect the rotation speed of the engine, and this rotation speed signal is input to a controller 27.

The controller 27 issues a regeneration request for the filters 11 and 12 at regular intervals, and, based on the regeneration request and the rotation speed signal of the rotation speed sensor 26, the solenoid valves 17, 18, 24, 25 and the electric heater 21. Is controlled. Reference numeral 28 denotes a battery.

Next, the contents of control by the controller 27 will be described with reference to the flowchart of FIG.

A regeneration request for each of the filters 11 and 12 is sequentially and periodically generated (for example, every five minutes), and when this regeneration request is issued, the corresponding filter is backwashed and heater control is started.

In the case of the filter 11, the backwashing operation
The shutter valve 15 is closed to prevent exhaust air from flowing to the filter 11 side, and the solenoid valve 24 is opened to send high-pressure air from the air reservoir 19 to the backwash nozzle 22 and blow out toward the filter 11 to capture air. The collected particulates are blown down into the combustion chamber 20. At this time, the solenoid valve 24 is driven to open and close so as to blow out high-pressure air in a pulse for a very short predetermined period. The same applies to the filter 12.

In the heater control, first, the engine speed N
Is higher than a specified value N ₀ (for example, 1000 rpm) (step 1).

If the rotation speed N is higher than a specified value N ₀ ,
The heater 21 is turned on, and the ON time Tac ₁ is counted (steps 2 and 3), and the specified time T ₁ (for example, 3 minutes) is kept as it is.
Is passed, the heater 21 is turned off (step 4,
5).

On the other hand, when the rotation speed N is equal to or less than the specified value N ₀ , or when the rotation speed N is equal to or less than the specified value N ₀ while the heater 21 is on, the heater 21 is turned off (step 1 → 6).

At this time, the counting of the off time Tac ₂ is started, and if the rotation speed N becomes higher than the specified value N ₀ while the heater 21 is off (steps 7 and 8), the heater 21 is turned off in step 2. turned, also the off time Tac ₂ exceeds a predetermined time T ₂ (e.g., 2 minutes), maintaining from that point the heater 21 turned on (step 9-12).

In any case, the heater 21 is turned on within a range where the total on-time Tac ₁ does not exceed the specified time T ₁ .

When the filters 11 and 12 are regenerated as described above, the high-pressure air in the air reservoir 19 is flushed with the backwash nozzles 22 and 2.
3, the electric heater 21 is turned on for a predetermined period, so that the particulates that have fallen into the combustion chamber 20 can be quickly and efficiently burned and removed by the electric heater 21, thereby greatly reducing the power consumption of the electric heater 21. it can.

On the other hand, when the rotation speed of the engine is equal to or less than the predetermined value, the electric heater 21 is turned off, so that the load on the battery is reduced by reducing the power consumption when the engine is idling with a small amount of power generated by the generator. It can be greatly reduced.

In this case, when the rotation speed increases, the electric heater 21 is turned on.
Since the electric heater 21 is turned on after a predetermined time, the combustion is not delayed, and the accumulation of particulates can be prevented.

The above this invention, a filter for collecting particulates contained in the exhaust of the engine,
Fi by the downstream side during filter regeneration predetermined backwashing time blowing high-pressure air from <br/> air reservoir
Means dropping blow the filter of the collected particulate matter in the combustion chamber
And an electric heater that burns and removes the particulates
And a particulate trap device comprising:
Electrical heating to balloon time of high-pressure air from the air reservoir
Means for turning on the engine for a predetermined operation time, and an engine
Means for detecting the rotational speed, and the engine rotational speed being a predetermined value
In the following cases, the on-control of the electric heater is forcibly turned off.
Means to prevent excessive load on the battery
And properly burn the trapped particulates of the filter
The effect of being able to process is obtained .

When the rotation speed of the engine is lower than a predetermined value, the load on the battery can be greatly reduced by forcibly turning off the electric heater.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart for explaining control contents.

Claims (1)

(57) [Claims] 1. A filter by blowing a filter for collecting particulates contained in exhaust gas of the engine, the high pressure air from the air reservoir from the lower <br/> stream side during filter regeneration predetermined backwashing time the collected particulates and means to drop blown into the combustion chamber of the particulate trapping device comprising an electric heater for burning and removing the particulates, and the electric heater in the balloon timing of high-pressure air from the air reservoir for a predetermined operating time Means for controlling on, means for detecting the engine speed,
When the engine speed is lower than the specified value, turn off the electric heater.
Means for forcibly turning off the trapping control.