JPS60216017A - Exhaust gas particulate processing device in internal- combustion engine provided with turbocharger - Google Patents

Abstract

PURPOSE:To stabilize the combustion of a burner device, by increasing the supercharging pressure of a compressor upon operation of the burner device to increase the amount of supercharging air fed into the burner device. CONSTITUTION:Upon starting of regeneration of a trap, a second control circuit 22 receives a trap regenerating signal. Further, upon low speed and low load operation of an engine the second control circuit 22 delivers a signal to a stepping motor 18 so that a flapper 16 increases the flow rate of exhaust gas fed to the rotor of a turbine 15. Accordingly, the rotational speed of the turbine 15 is increased to raise the supercharging pressure of a compressor 14. With this arrangement the amount of supercharging air fed into a burner device through an air passage 20 is increased so that combustion of the burner device may be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an exhaust particulate treatment device for an internal combustion engine with an exhaust turbo supercharger.

<Prior art> The exhaust of internal combustion engines, such as diesel engines, contains many exhaust particulates whose main component is carbon.
A trap installed in the middle of the exhaust passage traps these particles and prevents them from dispersing outside.

A conventional example of such an exhaust particulate treatment device is shown in FIG. 1 (see Japanese Patent Application No. 85770/1983).

That is, a trap 5 for collecting exhaust particulates is connected via an exhaust pipe 4 to the outlet of a turbine 3 of an exhaust turbo supercharger 2 connected to an exhaust manifold 1 of an internal combustion engine. Collects fine particles inside.

Then, when a predetermined amount of particles are collected in the trap 5,
The burner device 6 provided upstream of the trap 5 is operated to heat and burn the particulates collected in the trap 5 by the burner device 6.

I am trying to regenerate Trap 5.

Further, a mixture of fuel supplied from the fuel injection valve T and supercharged air supplied from the intake passage 10 downstream of the compressor 9 of the supercharger 2 is introduced into the burner device 6 via the air passage 8. . A control valve 11 is interposed in the air passage 8, and this control valve 11 supplies supercharging air to the burner device 6 when the burner device 6 is in operation, while supplying supercharging air to the burner device 6 through the air control passage 12 when the burner device 6 is not in operation. It is configured to return air to the intake duct 14 of the air cleaner 13. Note that 15 is a glow plug for ignition.

However, in such a conventional exhaust particulate treatment device, air is supplied to the burner device 6 through the air passage 8 from the supercharging duct 10 downstream of the compressor 9 of the supercharger 3.

In the engine low-speed/low-load operation region, the exhaust energy is small and the driving force of the turbine is reduced, so the supercharging capacity of the compressor 9 is reduced and the air supply amount to the burner device 6 (02
quantity] was insufficient. For this reason, there was a problem in that the combustion operation in the burner device 6 was disabled and the trap 5 could not be regenerated.

As shown in Japanese Patent Application No. 57-163084, by changing the capacity of the turbine, the boost pressure of the compressor is suppressed in the engine high-speed operating range, while the compressor boost pressure is suppressed in the engine low- to medium-speed operating range. There is a method that increases the boost pressure of the burner, but even with this method, the amount of air supplied to the burner device was insufficient.

<Objective of the Invention> In view of the current situation, an object of the present invention is to provide an exhaust particulate treatment device that can supply air with sufficient combustion pressure to a burner device in an operating range such as a single engine at low speed and low load.

<Structure of the Invention> Therefore, the present invention includes an exhaust supply amount variable device that changes the amount of exhaust gas supplied to the turbine rotor, and a control means that controls the exhaust gas supply amount variable device according to the operating state of the engine. In the internal combustion engine with an exhaust turbo supercharger, the control means includes an operation detection means for detecting operation of the burner device, and receives a signal from the operation detection means and controls the exhaust supply amount variable when the burner device is operated. and trap regeneration control means for operating the device and increasing the amount of exhaust gas supplied to the rotor of the turbine. When the burner device is operated, the boost pressure of the compressor is increased to increase the amount of supercharged air supplied to the burner device, thereby stabilizing combustion in the burner device.

Embodiment> An embodiment of the present invention will be described below based on FIGS. 2 and 3.

First, to explain the configuration of an exhaust turbo supercharger similar to the conventional one, the engine has an intake manifold 11 and an exhaust manifold 1.
The compressor 1 of the exhaust turbo supercharger 13 is installed in the collecting part of 2.
4 and a turbine 15, respectively, to constitute an internal combustion engine with an exhaust turbo supercharger. This supercharger 13
A flapper 16 is provided on the turbine 15, and this flapper 16 has a stepping rotor 18 operated by a signal from the first control circuit 1T and a spring 16a.
The opening degree of the 7 lapper is controlled by the biasing force, and the flow rate of the exhaust gas supplied to the rotor of the turbine 15 (in other words, the momentum of the exhaust gas supplied to the turbine 150 is variably controlled. In the high-speed operation region, the flapper 16 suppresses the exhaust flow rate supplied to the rotor of the turbine 15 to a predetermined value to prevent the supercharging pressure of the compressor 14 from rising excessively. The exhaust flow rate supplied to the rotor of 15 is set to 7.
The structure is such that the rotational speed of the turbine 15 is increased by increasing the rotation speed of the turbine 15 and the supercharging pressure of the compressor 14 is increased by raising the engine torque at the bumper 16, thereby ensuring engine torque in the low and medium speed operating ranges. Here, the flapper 16 and the stepping rotor 18 constitute an exhaust gas supply amount variable device.

The clean side of the EnerCleaner 19 is connected to the inlet of the compressor 14 via an intake duct.

A trap (not shown) for collecting exhaust particulates is connected to the exhaust outlet of the turbine 15 via an exhaust passage 20. A burner device (not shown) is installed upstream of this trap. A mixture of fuel injected from a fuel injection valve (not shown) and supercharged air supplied from the discharge side of the compressor 14 of the supercharger 13 is introduced into this burner device through the air passage 21. It is configured to

Next, in the present invention, the following measures have been taken.

That is, a second control circuit 22 for operating the stepping motor 18 is provided. This second control circuit 2
2 receives an engine rotational speed signal and an engine load signal, and based on these signals, the second control circuit 22 controls the burner device while the engine is operating at low speed and low load (region (B) in FIG. 3). When a trap regeneration signal for combusting the compressor is input, a signal is output to the stepping motor 18 to cause the flapper 16 to increase the exhaust flow rate supplied to the rotor of the turbine 15 from the exhaust control amount by the first control circuit 17. 14 is configured to increase the supercharging pressure. Here, the second control circuit 22 serves both as an operation detection means and a trap regeneration control means. Further, the first control circuit 17 and the second control circuit 22 constitute a control means.

Next, the effect will be explained.

The exhaust gas that drove the turbine 15 of the supercharger 13 flows through the exhaust passage 2
The particulate matter in the exhaust gas is collected by the trap, and the exhaust gas is released into the atmosphere in a clean state.

When it is determined that a predetermined amount or more of exhaust particles have been collected in the trap, the differential pressure across the trap relative to the exhaust pressure upstream of the trap detected by a pressure sensor (not shown) reaches a predetermined value or more. When the inlet temperature of the trap detected by a temperature sensor (not shown) is below a predetermined value, the burner device is activated to heat and burn the exhaust particulates collected in the trap, thereby regenerating the trap.

At the start of this trap regeneration, a trap regeneration signal is input to the second control circuit 22. And one engine operating state is low speed.
When in the low load operation region (Fig. 3 (G) region), the second
A signal is input from the control circuit 22 to the stepping motor 18, and the flow rate of exhaust gas supplied to the rotor of the turbine 15 is increased by the flapper 16. Therefore, turbine 150
Since the rotational speed increases, the supercharging pressure of the compressor 14 increases.

As a result, the amount of supercharging air (02 amount) supplied to the burner device via the air passage 20 increases, so that combustion in the burner device becomes stable and exhaust particulates collected in the trap can be combusted.

In addition, in the medium/high speed operation region (Fig. 3 (A) region), the exhaust flow rate supplied to the rotor of the turbine 15 is large and the supercharging pressure of the compressor 14 is sufficiently increased.
The control circuit 22 supplies the air passage 20 with a sufficient amount of supercharging air for combustion to the burner device without operating the flapper 20.
Can be supplied via.

In addition, in this embodiment, the supercharging pressure of the compressor 14 (more supercharged air is summed to supply the burner device) without providing an air pump for supplying combustion air to the burner device, which simplifies the device and reduces its cost. In addition, the intake system switching control and exhaust gas introduction control disclosed in Japanese Patent Application No. 58-85770 are not required, thereby simplifying the control system and reducing costs.

Of course, in addition to the supercharging pressure control by the second control circuit 22, the flapper 16 controls the exhaust flow rate supplied to the rotor of the turbine 15 in the engine high-speed operating region by a signal from the first control circuit 17, as in the conventional case. This prevents the supercharging pressure of the compressor 14 from rising excessively, while at the same time increasing the exhaust flow rate supplied to the rotor of the turbine 15 in the engine low-speed/medium-speed operating region, increasing the supercharging pressure of the compressor 14. Although supercharging pressure control is performed to ensure engine torque, the exhaust gas supply amount in the low engine speed and low load operating region is set to be larger during trap regeneration.

<Effects of the Invention> As described above, the present invention operates the exhaust supply amount variable device by the control means when the burner device is in operation to increase the amount of exhaust gas supplied to the rotor of the turbine, thereby increasing the supercharging pressure of the compressor. As a result, sufficient supercharging air can be supplied to the burner device through the air passage, thereby stabilizing the combustion operation of the burner device and regenerating the trap. Further, since the supercharged air is supplied to the burner device by 5 vct using the supercharging pressure of the compressor, an air pump for supplying combustion air to the burner device is not required, and the cost of the device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a conventional example of an exhaust gas particle processing device, and FIG. 2 is a schematic diagram showing an embodiment of the present invention. FIG. 3 is a characteristic diagram for explaining the same device. 13... Exhaust turbo supercharger 14... Compressor 15... Turbine 16... Flapper 1B...
Stepping motor 21...Air passage 22...
Second control circuit

Claims (1)

[Claims] a trap installed in the exhaust passage of an internal combustion engine with an exhaust turbo supercharger to collect particulates in the exhaust; a burner device that heats and burns the exhaust particulates collected by the trap; and a burner device downstream of the compressor of the supercharger. an air passage for supplying supercharged air to the burner device; and an exhaust supply amount variable device for changing the amount of exhaust gas supplied to the rotor of the turbine of the supercharger;
An exhaust particulate treatment device for an internal combustion engine with an exhaust turbo supercharger, comprising: a control means for controlling the exhaust supply amount variable device according to an operating state of the engine, wherein the control means detects operation of the burner device. and trap regeneration control means that receives a signal from the operation detection means and increases the amount of exhaust gas supplied to the turbine which has activated the exhaust supply amount variable device when the burner device is activated. What is claimed is: 1. An exhaust particulate treatment device for an internal combustion engine with an exhaust turbo supercharger, characterized in that the device includes: