JPS588218A - Exhaust corpuscle purifier for diesel engine - Google Patents

Abstract

PURPOSE:To improve durability and safety and simplify structure, by making up a collecting material with a ceramic form of three-dimensional reticulate structure and installing a wall which sections an exhaust gas passage of the collecting material into plural lines. CONSTITUTION:A collecting material 28 is made up of a ceramic form while a wall sectioning an exhaust gas passage of a collecting material 28 into plural lines is installed and furthermore plural electric heater elements 26 are dispersedly arranged each at the upstream end of the collecting material 28 in order to meet each passage of the material 28. With this, the collecting material 28 gets strengthened itself and, what is more, combustion of the exhuast corpuscle is not diffused around wastefully, shortening the regenerating time as combustion is transmitted still earlier in the axial direction. In addition, since a drift of exhaust gas is obviated by dint of the wall 29, there is no fear of producing a portion of incomplete combustion at all.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas treatment device for a diesel engine, and relates to an exhaust gas treatment device for a diesel engine. In detail, carbon particles contained in exhaust gas and similar particulate matter (hereinafter referred to as exhaust particulates) are collected on an appropriate collection material by a physical method, and the trapped exhaust particulates are collected by a physical method. The exhaust gas that was incinerated during periodic fishing and regenerated with 1 collection material is sent to the 4IL particle purification device.

Most of these types of exhaust particulates are flammable, such as carbon particles, and these combustible particulates are collected,
K, which incinerates the collected particles and regenerates the collection material,
Conventionally, the following methods have been known, each of which has the following drawbacks.

(1) A method of throttling the intake system of the easel engine to raise the temperature of the exhaust gas and combust the exhaust particulates.This method raises the exhaust temperature sufficiently in the high load range of the engine, so that the exhaust particulates cannot be incinerated. Although this is possible, the exhaust temperature does not rise sufficiently in the low load range, making it impossible to incinerate exhaust particulates and nurturing the collection material.

(2) A method in which an oil burner is installed in the exhaust system of a diesel engine to raise the temperature of exhaust gas to a temperature at which exhaust particulates are combusted. This method is.

There are problems with the durability and safety of the oil burner.

Furthermore, the equipment is complicated) and the cost is high. If the flow of exhaust gas is changed to a de-crystalline flow and one flow is stopped for incineration and regeneration, the equipment becomes even more complicated.

(3) A method in which the air heater tm is fully opened to burn the exhaust particulates attached to the surface of the collection material, and the downstream 4 & fruit is self-combusted using it as a heat source.

This method requires an electric heater to be attached to the entire surface of the thinning material, which consumes a very large amount of power, making it difficult to be used as an automobile part. In order to reduce power consumption, it is necessary to deair the flow of VCFi and exhaust gas, and to stop one flow and burn it with an electric heater, which makes the installation complicated and costs 10,000 yen.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, improve durability,
It is an object of VC to provide an exhaust particle purification device for a diesel engine that is safe, has a simple structure, and has a low cost.

In order to achieve such an object, the present invention provides a collection material for exhaust particulates in the exhaust gas path of a diesel engine,
The thinning material is composed of a ceramic filter having a three-dimensional mesh structure, and a wall is provided to divide the exhaust gas flow path of the ceramic 7 ohm into a plurality of parts, and a plurality of electric heater elements are respectively installed on the upstream end surface of the ceramic 7 ohm. f: It is a special request that they are distributed and arranged so as to correspond to the valley flow path.

Preferably, these multiple electric heater elements are sequentially VC-heated, rather than being heated by -[K7711], thereby reducing power consumption. Since the electric heater elements are arranged in a distributed manner, they do not impede the flow of exhaust gas. Heating of the electric heater element can be controlled by a combinator device or the like. Also,
It is preferable to operate the electric heater element in a state where the temperature of the combined air gas is raised, in combination with a throttling means that throttles the intake passage of the carrot. Furthermore, in order to promote the combustion of exhaust particulates, it is desirable to supply secondary air to the exhaust gas upstream of the collection material, thereby further reducing the power required to heat the electric heater element. be able to. Note that it is preferable to regenerate the thinning material when the engine is idling.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings rkJf.

In the first diagram, l is the engine cooling 7mm, 2ri fuel injection pump, 6 is the intake system Wcti throttle valve, 14 is the diesel engine body, 15 is the transmission scene, and 1g is the exhaust manifold. The throttle valve 6 is connected to a negative pressure operated diaphragm valve 8 via a link 7.
This diaphragm valve 8 is connected to a negative pressure switching valve 9,)
(It is connected to a Paquiame pump 17' via a keyme piping 5. Also, the negative pressure switching valve 9 is connected to a microcombinator 0PU5 (1) via a distribution fi 12.

Therefore, when a command signal is manually applied to the negative pressure switching valve 9 from the PU 50 through the wiring 12, the vacuum path of the negative pressure switching valve 9 opens, and the negative pressure from the pump 17' flows through the piping 5. It is transmitted retroactively to the diaphragm valve 8 and operates the throttle valve 6 in the closing direction via the link 7t. This is a throttling means that throttles the intake passage.

The opening degree of the throttle knob (ruple 6) is detected by the throttle sensor lO via the wiring 11, and is detected by the throttle sensor lO via the wiring mx3*.
SOK is input.

The fuel injection pump 2 has a fuel pipe 4 connected to a fuel injection valve 4' of each cylinder, and injects fuel into the combustion chamber of the diesel engine to operate the engine.

The portion 12 of the exhaust line immediately downstream of the exhaust manifold 16 is fitted with a trapper container 23 . However, this exhaust manifold 1 is located downstream of the gathering part of the exhaust manifold 16.
6 may be made of cast metal or the like. Toratsuba container 2
As shown in Fig. 2(a) K, there is a thinning material (
Trap material) 28 is available. This trap material 28 is composed of a ceramic 7 ohm (7 ohm filter) having a ternary mesh structure. That is, it is possible to apply a 77mm 7 ohm medium to the exhaust gas, and it is possible to collect exhaust particulates in the exhaust gas between the 7 meshes.

In the present invention, a quantum direction wall 29 is provided that divides the exhaust gas flow path of the ceramic foam 28 into a plurality of parts. Such a wall 29 is used for packaging material 2 made of ceramic foam.
8 can be molded at the same time. This ceramic 7 ohm 28 has a catalyst supported in its upstream region 28& to promote combustion immediately after ignition of the exhaust collector. A plurality of electric heater elements 26 (FIG. 2(C)) are disposed on the upstream end surface 12 of the ceramic foam 28 in a distributed manner such that n corresponds to each flow path of the ceramic foam 28. Such an electric heater element 26 is manufactured by providing a recess 28b on the end face of the ceramic 7 ohm 28, as shown in FIG. a)
) It is convenient to hold and fix the
In the figure and FIG. 2(a), there is a terminal for supplying a 26km power source to each 20fi heater element, and the wiring from this power supply shoulder 20 to each electric heater element 26 goes beyond the honeycomb filter 27. It's cold. Further, in FIG. 1, 21 is a cut-back relay, which is connected to 0F (J50), 22 is a power source (batch! J), and 25 is a ground.

In addition, in the embodiment shown in FIG.
A device that supplies secondary 9 air to the upstream region of 8 is shown.

In the first evil implementation dog, the above-mentioned throttling means,
heating means by an electric heater element 26;

The secondary 9 gas supply means are operated in conjunction with each other.

For this purpose, engine operating conditions, exhaust gas conditions, etc. are detected and input to the 0PU50. That is, in FIG. 1, 3 is the engine load signal, 51 is the engine water temperature, and 5 is the engine load signal.
2a Engine speed signal.

53 is the exhaust pressure signal before the trapper (19 is the pressure cent)
, 54 is an exhaust gas temperature signal in front of the trapper, and 55 is a 1δ number for the trapper internal temperature, each of which is input to 0PU50.

FIG. 3 is a flow diagram showing the operation of trapper vessel regeneration. First, as mentioned above, as a condition, engine water 1
jAC51), engine negative # (3), engine speed C52), exhaust gas pressure (53J,) exhaust gas temperature before the trumpet (54),) inside the trumpet? S temperature (55) etc. are manually input to UP05011 as information. The regeneration time wT is determined mainly by the back pressure (53)K of the exhaust gas. That is, the exhaust gas discharged from the diesel engine flows into the direction 5 as shown by the arrow P (Fig. 2 (a)), and the particles contained therein are collected by the trapper material 28, where the fine particles accumulate. Since the pressure of the exhaust gas upstream of the trapper container 23 increases as the pressure increases, this pressure becomes an indicator of the accumulation of particulates.

After determining that it is time for regeneration, check the engine water temperature (51). This is to prevent regeneration from starting immediately after starting the %L engine. Engine water temperature is between 80℃ and IIO'CO, engine speed is idle 70 Q rpm, no load, trapper internal temperature 4
If the temperature is between 0°C and 800°C, regeneration is started. Instead, start throttling first. This't'LV: + Therefore,
When the exhaust gas temperature (54) in front of the trapper is confirmed to be 150° C. or higher, the CPU 50 issues a signal to energize the electric heater element 26. At the same time, the redundant switching pulp lf is activated to fill the upstream area of the collecting material 28 with a small amount of secondary air. This reduces air Jif by throttling:
This is done to promote the combustion of supplementary exhaust 5IL particles. [The judgment as to whether or not the air heater element 26 is heated and the exhaust collector is combusted is made based on the trapper internal temperature [(55) or the temperature (56) K in the downstream region of the collecting material 28. The time for energizing the electric heater elements 26 may be long enough to ignite the exhaust collector on the surface of the collecting material 28 (approximately 20 to 60 seconds), and all the electric heater elements 26 are energized at once. Instead of energizing them one by one, they are energized one by one. This can reduce power consumption. When the electric heater element 26 is energized, the energization order is counted up. In that case, the order of energization is such that it is calculated regardless of whether or not the exhaust particulates have been combusted, and then the next step is performed.
Throttling and secondary air introduction are then stopped and the process returns to reset.

FIG. 4 shows another embodiment of the present invention, and corresponds to FIG. 1. The difference from the central JliI example in Figure 1 is that
The difference is that the throttling mechanism that throttles the engine intake system and the secondary air supply device are removed. Other structures and functions are primary.
This is similar to the embodiment shown in the figure.

FIG. 5 shows the arrangement of electric heater clusters 3G coated with ceramic. Such element 30#
a suitable electric heating element, such as tungsten wrapped in aluminum foil and coated with ceramic; If such a ceramic heater element 3o is used, there is no risk that the heating element will be oxidized and deteriorated by exhaust gas.

The present invention has been described in detail above. In the present invention, since the wall 29 is provided on the thinning material 28 made of ceramic 7 ohm, the strength of the collecting material 28 itself is increased, and the combustion of the exhaust collecting material is prevented. This has the effect that combustion is not spread to the surroundings, and the combustion propagates quickly in the axial direction, shortening the exothermic time. Furthermore, in a case where such a wall 29 is not provided, the exhaust gas does not flow straight through the collection material 28, and there is a risk of causing a biased flow. Even though the electricity and gas are affected by the unbalanced current,
In the present invention, since the wall 29t as described above is provided, uneven flow of exhaust gas is prevented, and there is no possibility that a non-combustible portion will occur.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the diesel engine for FJA'i, Figure 2 (a) is a sectional view of the trapper container, Figure 2 (
b) is an enlarged view of a part of Fig. 2(a), #! 2
Diagram (C) is a diagram showing the arrangement of electric heater elements, 1g3I8
! ! J is a flow diagram showing the operation of regenerating the trapper vessel, FIG. 4 is a diagram corresponding to FIG. 1 showing another embodiment of the present invention,
FIG. 5 is a diagram showing an arrangement of ceramic-coated electric heater elements. 14...Diesel engine book Lx6...JilF
m manifold, 23... Fruit thinning material (trapper) '4g device, 26.30... Electric heater element, 28... Fruit thinning material (trap material), 29... li, 5G... microcomputer ( OPU). Figure 4 Rate Figure 5 Procedural Amendment (Voluntary) September 2, 1980 Director General of the Japan Patent Office Shima 1) Key Points 1. Indication of the incident 1988 Patent Application No. 105111 2. Name of the invention Diesel engine exhaust particulates Purification device 3, relationship with the case of the person making the amendment Patent applicant name (320)) Yota Automobile Industry Corporation 4,
Agent (3 other people) 5. Column of "Scope of Patent W!f#II Requested" in the 4th original subject specification Contents of the amendment as shown in the attached sheet 7 Attached *@ List of Amended Patent Claims'm From 1m L In a diesel engine having an exhaust particulate scavenger (28) in the exhaust gas path, the scavenger is composed of a ceramic 7 ohm having a ternary mesh structure, and the exhaust gas flow path of the ceramic foam is Wall that divides into multiple parts (2
9) kpeke, above the ceramic 7 ohm [41mK
A diesel engine exhaust particulate purification i rat characterized in that electric heater elements (26, 30) of Enoki i are arranged in a distributed manner so that each corresponds to each flow path.

Claims (1)

[Claims] L. In a diesel engine having an exhaust particulate collecting material (28) in the exhaust gas path, the collecting material is made of a 7 ohm ceramic having a ternary mesh structure, and the exhaust gas flow of the 7 ohm ceramic is A wall that divides the road into multiple parts (2
9), a wall (29) is provided that divides the exhaust gas flow path of the ceramic foam into a plurality of parts, and a plurality of electric heater elements (26, ao) are provided on the upstream end surface of the ceramic foam.
An exhaust particulate purification device for a diesel engine, characterized in that these are arranged in a distributed manner so as to correspond to each flow path.