JPS6128709A - Regenerating method of diesel particulate collecting member - Google Patents

Abstract

PURPOSE:To fire a Diesel particulate into combustion by heat of high temperature exhaust performing almost complete combustion, by advancing the opening timing of an exhaust valve in an engine without causing a change of its fuel injection timing. CONSTITUTION:If a flow of exhaust is worsened by accumulating a particulate to be deposited on a collecting member, an operating signal is output from a controller to a slider driving mechanism S1. Then a relative rotary angle regulating mechanism M1, causing the displacement in the first cam 27a and the second cam 27b and changing their cam profile, increases an effective valve opening. Accordingly, the deposited particulate is fired into combustion by advancing the opening timing of an exhaust valve and feeding high temperature exhaust to the collecting member.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention regenerates the diesel particulate collection member tube by burning the particulates collected by the diesel particulate collection member installed in the exhaust system of a diesel engine using the heat of the exhaust gas. Regarding how to.

Diesel engine exhaust contains combustible, carbonized fine particles, and particulates, which are metal objects. Particulates are harmful to the human body and cause the exhaust to turn into black smoke. I try to collect curates.

As the collection member, heat-resistant light foam or the like is used. If particulates are simply collected using this collection member, the particulates will collect and accumulate and block the exhaust passage, so it is necessary to burn and remove the accumulated particulates. The particulates were incinerated using a burner, the particulates were impregnated with a catalyst to lower the spontaneous ignition temperature of the particulates, and the fuel injection timing was significantly delayed to raise the exhaust temperature. Ta. However, although the method of incineration using a burner is reliable, it is expensive because it requires a burner and its ancillary equipment, and there are also reliability problems such as the exhaust gas staining the shibana and making it unusable when needed. be. In addition, with the method of significantly retarding the fuel injection timing, if you try to raise the temperature of the exhaust gas to a temperature sufficient for particulate combustion, combustion will be poor.
If unburned fuel is released into the exhaust, bad odor, white smoke, and Wm will be generated.

Furthermore, the output decreases significantly.

The present invention was made in view of the above situation, and the heat of the exhaust gas ignites and burns the venticulate. It is an object of the present invention to provide a new method for regenerating a collection member that does not cause deterioration.

The gist of the present invention to achieve the above object is to provide a method for burning particulates collected by a diesel particulate collection member provided in the exhaust system of a diesel engine, the method of burning particulates in the exhaust gas without changing the fuel injection timing in the engine. The opening timing of the valve is advanced, and the particulates are ignited and combusted by the heat of the completely combusted high-temperature exhaust gas.

Next, an embodiment of the collection member regeneration method according to the present invention will be described based on the drawings.

FIG. 1 shows the overall configuration of a di-zel particulate collection member regeneration system as an example to which the present invention is applied.

In the LIT diesel engine, an exhaust passage 2 is provided with a collection member 3 that captures particulates in the exhaust gas. As mentioned before, particulates are I/C
, are combustible fine particles mainly composed of carbon and hydrocarbons, with an average diameter of about 0.3 μm, and self-ignite at temperatures above about 500°C (350°C or above in the presence of an oxidation catalyst).

Further, as the collection member 3, a deep collection type catalyst-equipped heat-resistant ceramics having a resistance of 7 ohm is used. The collection member 3 communicates with the atmosphere through a muffler 4t, and receives exhaust from the engine 5 through a turbine of a turbocharger 5 and a heat insulation pipe 6t.

In the intake 11i path 7 of this diesel engine l,
An air cleaner, a compressor for the turbocharger 5, and an intake throttle valve 9 are installed from the upstream side (atmospheric side), and this intake throttle valve 9 is also connected to the downstream intake passage.
Turbocharger 50! An exhaust gas recirculation passage (EGR passage) 10 is interposed between the upstream exhaust passage (i pin) and the upstream exhaust passage, and an exhaust gas recirculation amount control valve (EGR valve) 10 is installed in the BGR passage 10. is interposed. The intake throttle valve 9 is driven to open and close by a pressure-responsive actuator 12,
The EGR valve 11 is driven to open and close by a pressure-responsive actiniator 13. 14 is a fuel injection pump, which changes the phase angle between the camshaft of the injection pump and the engine side drive shaft,
A timer 15 is provided to change the fuel injection timing.

Furthermore, this collection member regeneration device includes temperature sensors 16, 17, and 18 that detect the upstream, internal, and downstream temperatures of the collection member 3, and pressure loss between the upstream and downstream sides of the collection member 3. Pressure sensor to detect 19 degrees; rotation speed sensor to detect engine speed 20 degrees; pump lever opening sensor to detect pump lever opening sound 21. A pressure sensor for detecting the full opening of the intake throttle valve 9 and a potentiometer 23@f for detecting the opening of the 22% BGR valve 11 are provided. The signals from these nodes t16 to t23 are input to the controller (ECU), and this
CU) The reproduction timing is determined, and control signals are output to each section for reproduction control.

In the present invention, the regeneration signal from the ECU is used to advance the opening timing of the exhaust valve compared to normal operation. To,
It uses a variable profile cam device that changes the feel of the cam that opens and closes the exhaust valve. The case 2617- is attached to the stem 25 of the exhaust valve 24 of the diesel engine l.
so that the cam 25 can come into wide contact with the cam 27.
is composed of a fifth cam 27M and a second cam 27b. The first cam 27ali, 1 as shown in FIG.
It is fixed to a cylindrical outer camshaft 28, and a tin groove 29 is attached to the end of the cylindrical outer camshaft 28.
are connected via a relative rotation angle adjustment mechanism M2t-. The first cam 27a and the second cam 27b and #i have the same cam profile, and on their outer peripheries are a large diameter part 27c with a radius of about 1, a small diameter part 27d with a radius r, and a large diameter part. 27C and an intermediate portion 27e connecting the small diameter portion 27d with a smooth curve. Cylindrical outer camshaft 21HC.

The second cam 27b is loosely fitted and a through hole 30 that is long in the circumferential direction is formed), and the second cam 27b and the cylindrical inner camshaft 31 are connected through the through hole 30 as a connecting member. It is fixed by the bin 32FC. Then, the end of the cylindrical outer camshaft 28 ic hs cylindrical inner camshaft 31 is rotated (-
A [A relative rotation angle adjustment mechanism M, which constitutes the straightening machine #l, is connected. This relative rotation angle adjustment mechanism M1 is provided with a first elongated hole 33 formed in the cylindrical outer cam shirt 28, and a cylindrical inner cam in a direction intersecting with this first elongated hole 33. The shaft 31 has a 20th
A long hole 34 is formed, and a slider member 36 is fitted into the intersection 35 of the first long hole 33 and the twentieth long hole 34 . A slider member 36 is rotatably mounted on the shaft portion 36a and on this detail 36a.

Rotors 36b contact slot holes 33 and 34, respectively.

36C)% This slider member 86 is
It is fixed to the annular member 37. The annular member 37 is rotated through the bearing 38! [The nut 39 connected to the cylindrical inner shaft 40 is configured to be allowed to move in the axial direction and prohibited to rotate in the circumferential direction.] They are screwed together, and a first step motor 41 is connected to the other end of the cylindrical inner shaft 40 . These annular members 37. The bearing 38, the nut 398, the cylindrical inner sleeve 40, and the first step motor 41 constitute a slider drive mechanism SR. First step motor 41 force (91 cylindrical inner shaft 40 by rotating)
The nut 39 that is screwed into the
), the slider member 36 is driven in the same direction, and the alignment state of the first elongated hole 33 and the second elongated hole 34 changes from the state shown in FIG. 8 to that shown in FIG. is driven to the state shown. As a result, the cylindrical inner camshaft 31 rotates relative to the cylindrical outer camshaft 38 as indicated by the reference numeral in FIG. In addition, the cylindrical inner shaft 4
When the nut 39 screwed into the slider 1 is driven to the left in FIG. 3 (see reference numeral E in FIG. 10), the slider member 36 is driven in the same direction.

The alignment state between the first elongated hole 33 and the second elongated hole 34 is -8
The state shown in the figure can be driven to the state shown in FIG. 1O.

This results in a cylindrical inner camshaft 31.

As shown by the symbol F in FIG. 10, it rotates relative to the cylindrical outer camshaft 28.

The first step motor 411'ltsECU color control signal is supplied g:r+-. Further, the relative rotation angle adjustment mechanism M2 has almost the same configuration as the relative rotation angle adjustment mechanism M□. That is, as shown in FIG. 3, the relative rotation angle adjustment mechanism M2 includes a cylindrical outer camshaft 28.
A third elongated hole 42 is formed in the tin rocket 29 in a direction intersecting the third elongated hole 42.
A 40th elongated hole 43 is formed in the third elongated hole 42.
A slider member 45 is fitted into the intersection 44 of the fourth elongated hole 43 and the fourth elongated hole 43 . The slider member 45 is the detail 4
5&, is rotatably attached to this detail 458, and
It consists of α-ta 45b and 45c that are in contact with the elongated holes 42 and 43, respectively.

This slider member 45 is fixed to an annular member 46. The annular member 46 is connected to a nut 48 via a bearing 47', and the nut 48 is configured to be allowed to move in the axial direction and prohibited from rotating in the circumferential direction. Furthermore, a second step motor 50 is screwed onto one end of the first cylindrical outer shaft 49 and connected to the other end of the first cylindrical outer shaft 49 . These annular members 46
．． Bearing 47. The nut 481 cylindrical outer shaft 49 and the second step motor 50 are connected to the slider drive mechanism Sx
It is composed of k. And the second step motor 501
C#:t, control signals are supplied from the ECU.

In addition, the reference numeral 51 in the figure indicates a bearing.
2a camshaft bearing cap.

Reference numeral 53 indicates a front cover, and reference numeral 54 indicates a cylinder head.

Since the variable profile cam device is configured as described above, the rotational driving force from the drive belt etc. is supplied to the sprocket 29, and the rotational driving force transmitted to the sprocket 29 is transmitted to the relative rotation angle adjustment mechanism M2. to the cylindrical outer camshaft 28. This is good 1
A cam 27 connected to the cylindrical outer camshaft 28 abuts the stem 25 of the exhaust valve 24 via the case 26,
Open and close the exhaust valve 24.

When the pressure loss detected by the pressure sensor 19 exceeds a predetermined value,
When particulates accumulate on the picks and the collection member 3 and the flow of exhaust gas deteriorates, the controller ECU outputs an actuation signal to the slider drive mechanism S, and the relative rotation angle adjustment mechanism M causes the slider drive mechanism S to move. A deviation occurs between the cam 27m and the second cam 27b, the cam profile is changed, the effective valve opening is increased, and the opening timing of the exhaust valve 24 is advanced. The advantage of opening the exhaust valve 24 earlier is that, up until now, the exhaust was emitted some time after combustion was completed, but now it is emitted immediately after complete combustion (main combustion), and exhaust gas of about 400C is emitted. It turns out. This high-temperature exhaust gas is transferred to a heat insulating pipe 6,
The particulate matter passes through the exhaust passage 2 to the collection member 3, and the particulates deposited on the collection member 3 are ignited and burned. Whether or not the particulates have been incinerated is determined by the pressure loss detected by the pressure sensor 19. However, when the pressure drop falls below a certain value, it means that the incineration of particulates is complete, and the profile of the cam 27 is returned to its original state according to a command from the controller ECU.

The above control sequence is shown in a flowchart as shown in FIG. Moreover, when the combustion process is shown in p-v, FIG. 6, it becomes as shown in FIG. 11. Actual IiI is usually C) f cycle and Al,
The broken line indicates the cycle during particulate regeneration.In the above embodiment, the opening timing of the exhaust valve is changed by changing the shape of the cam. Various types, such as those that change the phase, can be used.

As described above in detail based on the embodiments, according to the method for regenerating a particulate collection member according to the present invention, the opening timing of the exhaust valve is advanced to obtain high-temperature exhaust gas, and the particulate collection member is Because the fuel is ignited and burnt, the fuel injection timing remains unchanged and the main combustion is the same as in normal operating conditions.)
, to open the exhaust valve early after the main combustion has finished.

There is little unburned savings, bad odor and white smoke! No smoke is emitted, and there is little reduction in output.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a system for carrying out the collection member regeneration method according to the present invention, Fig. 2 is a flowchart of one embodiment, Fig. 3 is a vertical cross-sectional view of a variable profile cam device, and Fig. 4 , FIG. 5 is a sectional view taken along the line W-IV and a sectional view taken along the line v-■. FIGS. 6 and 7 are perspective views of the cam in different states. Figures 8 to 10 are developed views of the profile adjustment mechanism. FIG. 11 is a p-v diagram. Inside the drawing. l is a diesel engine. 2 is an exhaust passage, 3 is a diesel particulate collection member, and 19 is a pressure sensor. 24 is an exhaust valve. 27 is a cam, M, , M, is a relative rotation angle adjustment mechanism.

Claims (1)

[Claims] A method of burning particulate matter collected by a diesel particulate collection member installed in the exhaust system of a diesel engine, in which the opening timing of the exhaust valve is advanced without changing the fuel injection timing in the engine, resulting in almost complete combustion. A method for regenerating a diesel particulate collection member, characterized in that the particulate is ignited and burned by the heat of high-temperature exhaust gas.