JPH0710011Y2 - Particulate trap regeneration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a particulate trap regenerator, and more particularly to a particulate trap (hereinafter simply referred to as trap) regenerator equipped with a gas backwash device. It is about.

[Conventional technology]

As a conventional trap regenerator, high heat is directly supplied to the trap that collects particulates, and the heat is incinerated to regenerate the traps. It is known that regeneration is performed by flowing a washing gas and removing the particulates trapped in the trap by the backwash airflow.

Among these regenerators, the latter has been proposed for regenerating traps by backwashing airflow. JP-A-62-26312
JP-A-64-77715 and JP-A-1-159408
In the apparatus disclosed in Japanese Patent Laid-Open Publication No. 2003-242242, a backwash nozzle that opens toward the trap is provided on the downstream side of each honeycomb-shaped filter body (trap), and when the trap reaches a predetermined state, the backwash nozzle The high-pressure gas is blown toward the trap from the direction opposite to the normal exhaust gas flow direction, and the particulates trapped in the trap are removed from the trap by this backwash airflow.

[Problems to be solved by the device]

For example, a trap regeneration device by backwashing as described above,
When applied to the diesel engine of a 4-ton vehicle, the pressurized gas for backwashing requires about 60 to 80 liters (1) at atmospheric pressure for one regeneration operation.

On the other hand, the pressure of the air tank, which is the source of pressurized gas for backwashing in the case of a normal diesel engine for vehicles, is 6 to 8 kg / c.
It has a m ² capacity of about ²⁰ liters, and the amount of gas that can be stored is only 120 to 160 liters under atmospheric pressure.

Therefore, if the regeneration operation is performed without replenishing the air tank, the air tank will be 3-4 kg / cm in one regeneration operation.
Since it causes a pressure drop of ² , the air compressor installed in the engine is used as a source of pressurized air to prevent this.

However, the amount of pressurized gas generated by the air compressor increases in proportion to the number of revolutions of the engine. Regular 6-8k
Time to return to g / cm ² (4 for idling
It took about 5 minutes), and if an air brake or the like is used in a low pressure state before restoration, there is a problem that it becomes a very dangerous state such that the braking effect deteriorates due to insufficient pressure.

Therefore, an object of the present invention is to prevent a dangerous decrease in the air pressure in a particulate trap regenerating device with a backwash airflow generating device equipped with such a pressurized air generating source.

[Means for Solving the Problems]

To achieve the above object, in a particulate trap regenerating apparatus according to the present invention, an engine speed detecting means, an engine load detecting means, a particulate trap provided in an engine exhaust pipe, and the trap are provided. Nozzle for backwash provided on the downstream side, a tank for supplying high-pressure gas to the nozzle, an electromagnetic valve provided in a pipe connecting the nozzle and the tank, and when a predetermined backwash cycle is reached,
Control means for opening the solenoid valve to regenerate the trap by backwashing only when the rotation speed and the load exceed respective predetermined values;
Is equipped with.

[Action]

In the present invention, the control means checks the engine speed and load when a predetermined trap regeneration cycle is reached, and opens the solenoid valve only when it is determined that both values exceed the respective predetermined values. The high-pressure gas stored in (1) is blown out from a backwash nozzle provided downstream of the trap toward the trap.

Then, the backwash airflow whose flow direction is opposite to that of the normal exhaust gas removes the particulates trapped in the trap from the trap, thereby eliminating the clogging of the trap.

Therefore, the trap is regenerated so as to be able to collect the particulates in the exhaust gas again.

The high-pressure gas in the tank used in such a backwash device is usually replenished by a compressor driven by the engine, so the replenishment amount is small when the engine speed is low. Low rpm
When the load is low, the backwash is not performed to prevent the tank internal pressure from decreasing.

In this case, since the amount of particulates emitted is low due to the low rotation speed and low load, backwashing of the engine at low rotation speed
There is no particular problem even if postponed until it is outside the low load range.

Even when the engine speed is low, the amount of particulates is increased when the load is large. In this case, therefore, the backwashing is controlled to be performed periodically.

〔Example〕

FIG. 1 is a system configuration diagram of an embodiment of a particulate trap regenerating apparatus according to the present invention. 1 is an engine, 2 is an exhaust pipe of the engine 1, and 3 is a trap provided in the exhaust pipe 2. It is provided with an exhaust part 3a for washing air and a tray 3b for particulates removed by backwashing. Also,
The backwash nozzle 4 is provided on the downstream side of the trap 3 with its outlet facing the trap 3, and 5 is connected to the backwash nozzle 4 by a pipe 5a and stores high-pressure air normally supplied from an air compressor. An air tank, 6 is an electromagnetic valve provided in the pipe 5a, 7 is a power battery, 8 is a load sensor of the engine 1 such as an intake amount, and 9 is a rotation speed sensor of the engine 1.

Then, when 10 determines that the backwash cycle has been reached by the built-in timer (not shown), the sensors 8 and 9 detect the engine 1
Only when it is determined that the rotational speed and the load of the engine are read, and both of these values exceed the predetermined values, the solenoid valve 6 and the exhaust unit 3a are opened, and the high-pressure air stored in the air tank 5 is backwashed by the backwash nozzle 4
From the trap 3 to remove the particulates trapped in the trap 3 from the trap 3 by this air flow.
It is a control unit (hereinafter abbreviated as C / U) as a control means for regenerating the trap 3 so that the particulates can be collected again by dropping the trap 3b.

FIG. 2 is a flow chart of a program stored and executed in the C / U 10 shown in FIG. 1, and the operation of this embodiment will be described based on this figure.

When this program is started by the driver turning on the key switch, etc., the C / U10 resets the built-in timer and resets the initial value of time to 0 (step S in Fig. 2).
Together with 1), the engine speed Ne and the engine load L are read from the respective sensors 9 and 8 (at step S2).

Then, the measurement of the time t is started (the same step S3), and it is determined whether or not a predetermined period (in this embodiment, 5 minutes, during which the trapping of particulates is continued in the trap) is reached. Check whether or not (step S4).

When it is determined that the predetermined cycle has been reached, the C / U 10 determines whether the engine speed and the load of the engine 1 are both lower than a predetermined value (in this embodiment, the engine speed Ne = 1000 rpm and the load L = 1/2). Check (the same step S5).

While it is determined in step S5 that the engine speed and the load of the engine 1 are both lower than the predetermined values, the check is continued.
If it is determined that the value exceeds the predetermined value, the C / U 10 performs a well-known backwash operation (step S6).

That is, the solenoid valve 6 and the exhaust part 3a of the trap 3 are opened to blow out the high-pressure air stored in the air tank 5 from the backwash nozzle 4, and the blown backwash airflow is exhausted to the particulate collection part of the trap 3 normally. The gas flows in the direction opposite to the flow direction and is exhausted from the exhaust unit 3a.

The backwash airflow removes the particulates trapped in the trap 3 from the trap 3 and drops them on the tray 3b, and either discharges them all together or heats and burns them by providing a heating means on the tray 3b. Good. All of these are well-known techniques.

When the C / U 10 determines that the predetermined conditions are reached and the backwash regeneration of the trap 3 is completed, the C / U 10 closes the solenoid valve 6 and the exhaust unit 3a, and ends this program.

[Effect of device]

As described above, according to the particulate trap regeneration device of the present invention, the backwash operation is not performed when the engine speed is low and the load is low, so that the following unique effects can be obtained. .

i) Since the backwashing air consumption can be reduced, it is not necessary to add an air tank or increase the capacity of the air compressor.

ii) The backwashing operation gives stress to the trap and deteriorates its durability, but the amount of particulates trapped is small at low rotation speed and low load, and such backwashing when unnecessary is eliminated. Thereby, the durability of the trap can be improved.

iii) The reliability of these components can be improved by reducing the load on the air compressor and reducing the number of times the solenoid valve is turned on and off.

iv) Fuel efficiency can be improved by reducing the load on the air compressor

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a particulate trap regeneration device according to the present invention, and FIG. 2 is a flow chart diagram of a program stored and executed in a C / U of the present invention. . In FIG. 1, 1 is an engine, 3 is a particulate trap, 4 is a backwash nozzle, 5 is an air tank, 6 is a solenoid valve, 8 is a load sensor, 9 is a rotation speed sensor, and 10 is a control unit (C / U). Are shown respectively.

Claims (1)

[Scope of utility model registration request] 1. An engine speed detecting means, an engine load detecting means, a particulate trap provided in an exhaust pipe of the engine, a backwash nozzle provided downstream of the trap, and a high pressure for the nozzle. A tank for supplying gas, an electromagnetic valve provided in a pipe connecting the nozzle and the tank,
When a predetermined backwash cycle is reached, control means for opening the electromagnetic valve to backwash and regenerate the trap only when the rotational speed and the load exceed respective predetermined values. Regeneration device for particulate traps.