JPS6115205Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an exhaust gas purification device that burns and processes particulate contained in the exhaust gas of a diesel engine.

Diesel engines contain harmful exhaust substances such as carbon in their exhaust, so various measures have been taken to purify them.

As one of the exhaust countermeasures, there is an exhaust purification device that collects and processes particulate matter such as carbon in the middle of the exhaust pipe.

This conventional exhaust purification device is equipped with a trap device that collects particulates discharged from the combustion chamber in the middle of the exhaust pipe, and a burner, heater, etc. that heats and incinerates the collected particulates immediately upstream of this trap device. A combustion treatment device is installed.

According to this exhaust gas purification device, when particulate matter gradually accumulates and the trap device becomes clogged, this particulate matter is periodically heated and incinerated to convert it into clean gas and remove harmful substances from the exhaust gas. It can be done.

However, with such conventional exhaust purification devices, the collected particulates are burned and the trap device is regenerated according to the distance and time traveled by the vehicle, so the engine does not continue to operate under high load. If the trap device is clogged, it may not be able to process the collected particulate, which may cause the engine exhaust pressure to rise too much, or conversely, cause the engine to continue operating at a low load. In this case, the combustion treatment device is activated before only a small amount of particulate matter has accumulated in the trap device, resulting in a problem that fuel consumption increases more than necessary.

The present invention was developed with a focus on these problems, and includes a means for accurately detecting the amount of fuel consumed by the engine, and this detection signal indicates that when the fuel consumption reaches a certain amount, combustion is started. It is an object of the present invention to provide an exhaust gas purification device that solves the above problems by operating a processing device.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 1 is an exhaust pipe, 2 is a trap device, 3 is a combustion processing device, 4 is a fuel consumption meter as a fuel detection means, and 5 is a control means for operating the combustion processing device 3.

The trap device 2 is equipped with a steel wire coated with alumina, and this part is designed to collect particulate matter in the exhaust gas.
This device 2 is installed in the middle of the exhaust pipe 1.
Further, the trap device 2 may have an exhaust passage formed in a porous shape, and a portion in contact with the exhaust flow may be coated with platinum.

The combustion processing device 3 is composed of a burner 6 provided upstream of the trap device 2 and a glow plug (ignition device) 7 provided immediately downstream of the burner 6. The burner 6 is connected to a fuel injection pump 8.
The glow plug 7 injects the fuel supplied from the exhaust gas into the exhaust gas, while the glow plug 7 ignites the mixture of the injected fuel and the air in the exhaust gas.

The fuel pump 8 and the ignition device 7 are operated by a control means 5 driven based on a signal from the fuel consumption meter 4.

When the control means 5 determines that a certain amount of consumed fuel has been reached based on the signal from the fuel consumption meter 4, the control means 5 generates a fuel injection signal that drives the injection pump 8 and an ignition signal that operates the ignition device (glow plug) 7. are input to the injection pump 8 and glow plug 7, respectively. Note that 9 is a battery, and 10 is an ignition switch for the engine.

In this case, the control circuit 11 constituting the control means 5
When the cumulative value of fuel consumption exceeds a predetermined value according to the signal from the fuel consumption meter 4, the fuel injection pump 8
is operated to supply fuel to the burner 6 and to make the glow plug 7 red hot to ignite the air-fuel mixture from upstream.

As a result, when the high-temperature ignition gas passes through the trap device 2, it heats and incinerates the collected particulate that has been sufficiently collected.

The fuel consumption meter 4 calculates the amount of fuel consumed by integrating the time during which a needle valve of a fuel injection valve (not shown) of the engine is open.

In addition to the one shown in FIG. 1, the combustion treatment device 3 may be an electric heater or any heating means that can raise the temperature of the exhaust gas to a temperature sufficient to burn the collected particulate.

It has been confirmed through experiments that the relationship between the fuel consumption rate and the particulate discharge rate is approximately proportional, as shown by the diagonally shaded area in FIG.

With this configuration, when the signal from the fuel consumption meter 4 is input to the control circuit 11 and it is determined that a certain amount of fuel consumption has been reached, the control circuit 11 energizes the glow plug 7 to close its tip. The part becomes red hot.

When the glow plug 7 is sufficiently heated, the fuel pump 8 is activated based on a signal from the control circuit 11, and fuel is injected from the burner 6.

This injected fuel mixes with air in the exhaust gas, and this air-fuel mixture contacts the glow plug 7 to generate high-temperature gas.

This high-temperature gas burns and incinerates the particulate matter collected in the trap device 2, converting the particulate matter into clean gas, and as a result, the trap device 2 is regenerated.

When the regeneration of the trap device 2 is completed, the operation of the fuel pump 8 and glow plug 7 is stopped.
The control circuit 11 inputs a fuel stop signal and an ignition stop signal to the fuel pump 8 and the ignition device 7, respectively.

After the regeneration of the trap device 2 is completed in this manner, the particulate displacement amount is again integrated from the fuel consumption rate.

Therefore, when the amount of collected particulate that is approximately equal to the preset amount of particulate is collected, this collected particulate can be appropriately incinerated, and the most appropriate method is used in terms of engine operating performance and fuel consumption. The trap device can be regenerated at the right time.

In this case, the fuel consumption meter 4 used was one that calculates the amount of fuel consumed by integrating the amount of time that the needle valve of the fuel injection valve is open, so a fuel meter that measures the remaining amount in the fuel tank, such as a float, It is not affected by the shaking or tilting of the vehicle body like when using
The accuracy of fuel consumption can always be detected.

As explained above, this invention includes a fuel detection means that calculates the amount of fuel consumed by integrating the time during which the needle valve of the fuel injection valve of the engine is open, and a fuel detection means that heats the collected particulate matter based on this detection signal. Since a combustion treatment device for incineration is provided, the amount of fuel consumed can be accurately detected, and the trap device can be regenerated at the most appropriate time. Therefore, it is possible to avoid an increase in exhaust pressure of the engine due to clogging of the collecting particulate, and it is also possible to suppress an increase in the amount of fuel consumed by the combustion processing device.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between the fuel consumption rate and particulate emission rate of a diesel engine. DESCRIPTION OF SYMBOLS 1... Exhaust pipe, 2... Trap device, 3... Combustion processing device, 4... Fuel consumption meter, 5... Control means, 7... Ignition device (glow plug).

Claims (1)

[Scope of utility model registration request] In an exhaust gas purification system that includes a trap device that collects particulate matter contained in the exhaust gas of a diesel engine, and a combustion treatment device that heats and incinerates the particulate matter when the trap device becomes clogged, The present invention is characterized by being provided with a fuel detection means that calculates the amount of fuel consumed by integrating the time during which the needle valve is open, and a control means that periodically operates the combustion processing device based on this fuel detection signal. Exhaust purification device.