JPS59211710A - Exhaust minute-particle disposing apparatus of internal-combustion engine - Google Patents

Abstract

PURPOSE:To obviate the necessity of an air pump installed independently by connecting an intake passage subsequent to the compressor outlet of a supercharger and an exhaust passage upstream from a trap through a secondary-air feeding passage equipped with a flow-rate control valve. CONSTITUTION:An intake passage 21 subsequent to the compressor 14 outlet of a supercharger 13 and an exhaust passage 18 upstream from a trap 19 are connected through a secondary-air feeding passage 22. In said passage 22, a secondary-air control valve 24 is installed to control the amount of feed of the secondary-air into a burner 20. The air which the burner 20 does not need is returned into an intake duct 16 through a secondary-air control passage 25.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field> The present invention relates to a device for treating exhaust particulates emitted from a quadruple internal combustion engine.

(Prior art) As a conventional exhaust particulate treatment device, for example, Japanese Patent Application Laid-Open No. 56
There is one described in Japanese Patent No.-115809.

This is constructed as shown in FIG. That is, a trap 5 for collecting particulates is connected via an exhaust passage 4 to the outlet of a turbine 3 of a supercharger 2 connected to an exhaust manifold l of an internal combustion engine, and the trap 5 traps particulates contained in the exhaust gas. When a predetermined amount of fine particles are collected, 1. The burner 6 provided in the stream of the trap 5 was operated to re-burn the particulates stored in the trap 5.

In order to regenerate the trap 5 in this way, it is necessary to supply fuel and air to the burner 6, so conventionally a system has been used in which air is supplied from an air pump 7 driven by an engine.

Regeneration of such a trap 5 (burning of fuel and particulates)
Under normal operating conditions, surplus oxygen in the exhaust gas is sufficient for the amount of oxygen required for Since the amount of surplus oxygen decreases and there is a shortage of oxygen for trap regeneration, air (secondary air) is introduced into the burner 6 from an engine-driven air pump 7. For this reason, the trap 5 regeneration device becomes large-scale, and the air pump 7 must be driven even in low-load ranges where there is no need to introduce air, which adds unnecessary load to the engine and worsens fuel efficiency. There was a problem.

<Object of the Invention> The present invention was made in view of the above-mentioned circumstances, and its purpose is to realize the necessary air supply without using an air pump that is used only for trap regeneration as in the past. The purpose is to introduce regeneration air into the exhaust passage upstream of the trap without waste only in the region.

<Summary of the Invention> In order to achieve the object as described in item h, the present invention connects the air supply passage after the compressor outlet of the supercharger installed in the internal combustion engine and the exhaust passage upstream of the trap with secondary air. By connecting via the supply passage and providing a secondary air control valve that controls the flow rate of secondary air according to the operating status of the engine, excess air discharged from the turbocharger compressor can be regenerated into the trap. The aim is to prevent wastage of engine power due to the installation of air pumps by making effective use of the engine power.

<Embodiment> FIG. 2 shows a first embodiment of the present invention, in which an outlet of a compressor 14 of a supercharger 13 and an inlet of a turbine 15 are provided at a meeting point of an intake manifold 11 and an exhaust manifold 12 of an internal combustion engine. are connected to form a diesel engine with a supercharger.

The clean side of an air cleaner 17 is connected to the inlet of the compressor 14 via an intake duct 16, and the trap 18 is connected to the exhaust outlet of the turbine 15 via an exhaust passage 18. By interposing a burner 20 upstream of the trap 18, the exhaust gas flowing into the trap 18 can be reheated by the burner 20 as required.

A secondary air supply passage 22 branched from the supercharging duct 21 extending from the compressor outlet of the supercharging @ 13 to the gathering part of the intake manifold 12 is connected to the L burner 20,
A fuel injection valve 2 is located near the downstream end of this secondary air supply passage 22.
3, it is possible to supply a mixture of fuel and air to the burner 20. A secondary air control passage 25 is branched from the secondary air supply passage 22 upstream of the fuel injection valve 23 via a secondary air control valve 24.
By connecting the burner 2 to the intake duct 16,
Air other than the air (secondary air) required for
I'm trying to return it to B. 26 is a glow plug for igniting the burner 20.

In the above configuration, the exhaust gas that drives the turbine 15 is introduced into the trap 19 through the exhaust passage 18, and fine particles such as carbon contained in the exhaust gas are collected by the trap 19, so that the exhaust gas remains clean. released into the atmosphere. Further, the fine particles are incinerated by the heating action of the burner 20, and the trap 18 is regenerated.

The burner 20 is activated when the exhaust pressure upstream of the trap 18 detected through a pressure sensor (not shown) reaches a predetermined value, that is, when the degree of clogging of the trap 18 due to collection of particulates reaches a predetermined value or more. In addition, it operates only when the exhaust gas temperature of the trap 18 detected via a temperature sensor (not shown) is below a predetermined value.

Here, when the burner 20 is in operation, the secondary air control valve 24 is opened, and the pressurized air taken out from the supercharging duct 21 passes through the secondary air passage 22 together with the fuel injected from the fuel injection valve 23 to the burner 20. be introduced. Then, it ignites and burns upon contact with the glow plug 2G that has been heated in advance, and the exhaust heat is heated to a temperature at which the particulates are combusted by this heat of combustion. It goes without saying that it is effective to provide a catalyst in the trap 18 in order to lower the combustion temperature of the particulates.

The operation of the burner 20 as described above is effective in region A (operating region of the supercharger) shown in FIG.
By appropriately delaying the fuel injection timing of the engine only while the engine is operating, it is possible to realize supply of secondary air up to region B shown in the figure. For this reason, the particulates collected in the trap 19 can be combusted (the trap 19 can be regenerated) in both areas A and B. The flow rate of the secondary air necessary for the operation of the burner 20 is controlled by the opening degree of the secondary air control valve 24, and surplus air that is not supplied to the burner 20 is passed through the secondary air control passage 25 to the intake duct 6. will be returned to.

FIG. 4 shows a second embodiment of the invention. In this embodiment, the compressor 1. A non-supercharging duct 27 is provided which connects the intake duct 6 (compressor pipe 14) to the intake manifold 12 by passing through the intake manifold 14. and an on-off valve 29 linked to the supercharging duct) 21 and the non-supercharging duct 27 by a link mechanism 28, respectively;
30, and a diaphragm 31 for operating the link mechanism 28 is provided, and the secondary air supply passage 22 leading from the supercharging duct 21 to the burner 20 and the intake manifold 12 are connected to the secondary air control passage 25 and the It is configured to connect via an air control valve 24 to return excess air to the intake manifold 12.

Also, the on-off valves 29 and 30 provided in the supercharging duct 21 and the non-supercharging duct 27 are normally used to fully open the supercharging duct 21 and fully opening the non-supercharging duct 27, as shown by broken lines in FIG. ing. Therefore, in this second embodiment, the same areas as in the first embodiment (A shown in FIG. 5,
Secondary air is supplied in area B).

In the CfR castle shown in FIG. 5, where the supercharging capacity of the compressor 14 is reduced, the on-off valves 29 and 30 operate as shown by solid lines in FIG. Fully open the duct 27. Then, air is introduced into the absorption manifold 12 by bypassing the compressor 2))-14, and the compressor 14 is introduced into the burner 20.
Pressurized air is supplied. Therefore, if the operating state of the engine (the operating state of the compressor sensor 14) is detected from the rotational speed, load, etc., or detected from the boost pressure and the on-off valve is switched and controlled, the trap can be trapped in almost all operating conditions of the engine. 18 can be played.

<Effects of the Invention> As explained above, according to the present invention, the intake passage after the compressor outlet of the supercharger and the exhaust passage upstream of the trap are connected via the secondary air supply passage, and the operating state of the engine is Since a secondary air control valve is provided to control the flow rate of secondary air according to the amount of air flow, there is no need to use a separate air pump as in the past. Therefore, the configuration of the exhaust particulate treatment device can be simplified, and at the same time, the air required for regenerating the trap can be economically supplied without waste, thereby improving the fuel efficiency of the engine.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of the conventional example, Fig. 2 is a schematic configuration diagram of the first embodiment of the present invention, Fig. 3 is a characteristic diagram of the secondary air supply area same as above, and Fig. 4 is a diagram of the second embodiment of the present invention. A schematic configuration diagram of the embodiment, FIG. 5 is a characteristic diagram of the same secondary air supply area.

Claims (1)

[Claims] In an internal combustion engine equipped with a supercharger, in which a trap for collecting particulates contained in exhaust gas and a means for regenerating the trap are interposed in the middle of the exhaust passage, the intake passage and the trap after the compressor outlet of the supercharger are provided. The flow rate of secondary air is connected to the upstream passage 1'A via a secondary air supply passage, and is introduced into the exhaust passage upstream of the trap via the secondary air supply passage depending on the operating state of the engine. A particulate processing device for exhaust gas from an internal combustion engine, characterized in that a secondary air control valve is provided to control the exhaust gas.