JP2004270690A - Control valve, and particulate matter removing device of exhaust gas using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary control valve of excellent heat resistance which is capable of controlling change-over to a filter unit by one control valve, and continuously and smoothly being regenerated even during a burning operation by an electric heater of a small capacity. <P>SOLUTION: A filter is divided into at least three compartments 3 to constitute a plurality of filter units, and regenerated by successively burning particulate matters (PM) collected by and deposited on the filter units. A valve element 11 of a control valve G is provided at a valve plate 13 having a serrated cam 16 rotatably combined with a crown-base type cam 15 provided in the center of a base plate 7. Through holes 9 of the same number as that of the plurality of corresponding filter units are formed in the base plate 7. A projection 17 of the serrated cam 16 is moved in the direction of a rotary shaft copying projections and recesses of the crown-base type cam 15, and when the projection 17 is abutted on a recess 21 of the crown-base type cam 15, one of the through holes 9 is closed by the valve element 11. The filter unit is regenerated by burning the particulate matters (PM) by energization-heating the closed filter unit. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

The present invention relates to a switching valve for switching or opening and closing a flow path of exhaust gas discharged from a vehicle equipped with an internal combustion engine, mainly a diesel engine, and a device for removing particulate matter from exhaust gas using the switching valve.
Specifically, a particulate matter (particulates = PM) composed of carbon fine particles in exhaust gas discharged from a diesel vehicle is configured by dividing a plurality of filter units provided in parallel or one filter into equal parts. A particulate regeneration device for exhaust gas such as a continuous regenerative diesel engine that collects and collects the particulate matter in a plurality of filter units and sequentially heats each of the filter units to incinerate particulate matter collected and deposited in the filter unit ( The present invention relates to a switching valve that provides a diesel particulate filter (DPF).

BACKGROUND ART Conventionally, pollution caused by a large amount of particulate matter, that is, carbon fine particles (PM) emitted from diesel vehicles such as trucks and buses has been regarded as a problem, and countermeasures have been taken.
As a typical particulate matter removal filter (DPF), as shown in FIG. 8, a plurality of alternately plugged through holes are provided in the hand direction, and a partition wall of the through holes is a honeycomb structure serving as a filter. There is a wall flow honeycomb in which each of the through holes forms an independent flow path.
Particulate matter (PM) is filtered and left inside the honeycomb structured partition walls. (In the figure, black arrows indicate PM-containing exhaust gas, and white arrows indicate PM-free exhaust gas.)

  However, in this wall flow honeycomb, since the filter partition walls (filter walls) are always clogged by filtering the particulate matter, a large amount of particulate matter accumulates on the filter and the engine output is reduced. Further, before the engine is stopped, the particulate matter clogged in the filter must be removed by incineration or the like to regenerate the filtration function.

For this reproduction, there is a so-called patch system disclosed in JP-A-2002-89235. When this signal is signaled that the filter has reached the specified clogging area, the engine is stopped at an appropriate place, the filter is taken out, and another filter is replaced.
The clogged filter is separately incinerated and regenerated at another facility.
However, if the filter becomes unable to travel beyond the clogged area with particulate matter during traveling, the exhaust gas to be treated is released by a bypass or released to the atmosphere by a relief valve. That is, if this continues, the particulate matter of the exhaust gas will be in a dripping state.

  Therefore, if possible, it is desirable that the filter be continuously regenerated even while the vehicle is running, that is, even when the engine is operating.

Diesel engine exhaust particulate matter removal equipment that can continuously regenerate the filter during this operation includes a catalytic oxidation method and a filter method (filtering with a filter). As shown in FIG. It is configured that F2 filters are switched and reproduced alternately.
That is, the particulate matter of the exhaust gas is first filtered and collected by the filter E. Then, the particulate matter adheres and accumulates on the filter E and is clogged. When the airflow resistance increases, the pressure sensor detects the particulate matter and switches to a new filter F by the switching valve G to perform filtration and collection.
In the meantime, the filter E closes the inlet of the filter E by the switching valve G, and regenerates the particulate matter clogged in the filter E by backwashing and / or incineration.
This is alternately repeated.

  On the other hand, a particulate matter removing device is provided as a filter unit by installing three to six small filters in one case in parallel, and a valve or a shielding member that rotates upstream of the exhaust gas is provided. By switching the filter units and sequentially heating them with the energization time for each filter unit shifted, heating energy required during regeneration is reduced and combustion control during regeneration is facilitated. JP-A-8-260945 shown in FIG. 5, JP-A-2001-132431 shown in FIG. 6A, JP-A-5-98936 and JP-A-6-264722 shown in FIG. And JP-A-2003-172125 are disclosed.

Japanese Patent Application Laid-Open No. 6-264722 discloses a cylinder that opens and closes a flow path of exhaust gas to a filter unit. In addition, JP-A-2001-132431, JP-A-8-260945 and JP-A-5-98936 disclose a method in which a valve or a shielding member is provided on a rotatable disk, and the disk is sequentially rotated by a step motor or the like, so that a predetermined Filter unit is shielded from exhaust gas channel. That is, the filter unit is energized and heated while preventing the inflow of exhaust gas, and the heater burns particulate matter (PM) to regenerate the filter unit.
Japanese Patent Application Laid-Open No. 05-098936 JP-A-06-264722 JP-A-08-260945 JP 2001-132431 A JP-A-2002-172125 JP-A-2002-089235

Japanese Unexamined Patent Application Publication No. 2001-132431 shown in FIG. 6A or Japanese Unexamined Patent Application Publication No. 5-98936 shown in FIG. 6B discloses a shielding member 32 for preventing the inflow of exhaust gas into one (predetermined) filter unit 2. A ring gear K, which is rotatable in the circumferential direction on the surface of the filter and is provided integrally with the shielding member 32, is disposed rotatably with respect to the support shaft 10 via a boss. The ring gear K is driven by a motor M which engages with the worm gear H or the pinion P.
That is, the movement amount (movement amount of one unit) of the shielding member 32 from the filter unit 2a to the adjacent filter unit 2b is determined based on the integrated value of the number of rotations detected by a sensor provided in the motor M. That is, the motor M is driven at a predetermined number of revolutions by a signal output from a control unit including a microcomputer, for example.

The valve or shielding member 32 of Japanese Patent Application Laid-Open No. 08-260945 shown in FIG. 5 is always arranged at a position where one exhaust gas introduction opening 33 is shielded and the introduction of exhaust gas to the filter unit 2 is blocked. The shielding member 32 is provided in a fan-like shape that covers substantially one-fourth of the partition plate 31 so as to slide on the front surface of the partition plate 31.
The fact that the fan-shaped shielding member 32 shields the opening 33 for exhaust gas introduction while rotatingly slidingly contacting the partition plate 31 also incinerates and removes particulate matter in the exhaust gas (an incineration temperature of 600 ° C. or higher is required). In the conventional method of rotating the shielding member shown in FIGS. 5 and 6, a large thermal strain is generated in the partition plate 31, the shielding member 32, the rotating member, and the sliding contact surface, so that the rotation cannot be performed and the shielding cannot be performed. Opening and closing the shield member 32 by sliding and rotating in a high-temperature region and a place where the temperature change is remarkable naturally causes a problem because the stable opening and closing operation function of the shield member 32 is uneasy. There is. Further, there is a problem that particulate matter (PM) deposited on the opening 33 and the like hinders rotation and shielding of the shielding member 32.
In the figure, A is a collection unit, and B is an incineration regeneration unit.

  The amount of movement of these shielding members and valves works by being driven at a predetermined number of revolutions by a signal output from a sensor provided in the motor or a control unit such as a microcomputer, so that the number of parts is large and a cause of failure. In addition, there is a problem that costs are high.

  The present invention has been made in view of the above-mentioned conventional problems, and has as its object to control switching and opening / closing of three or more filter units with one switching valve, and to filter particulate matter of exhaust gas with one filter. It is collected and deposited on a filter, which is incinerated with a small-capacity electric heater, and has excellent heat resistance so that it can be continuously and smoothly regenerated even during operation (no failure and little drop in ventilation resistance when switching the filter). It is an object of the present invention to provide a valve mechanism of a rotary exhaust gas particulate matter removal device.

In order to achieve the above object, the switching valve G according to the present invention is provided with a valve element 11 for opening and closing a flow path of exhaust gas, provided at at least one position on a valve disc 13 rotatable along an axis 10. The projection 17 of the saw-toothed cam 16 provided at the center of the board 13 corresponds to the concave 21 convex 22 of the crown-shaped cam 15 provided at the center of the substrate 7 having three or more through holes 9. By moving the valve disc 13 and the valve element 11 in the axial direction while moving in the axial direction while contacting and turning, the through hole 9 to the branch passage provided in the substrate 7 is opened and closed.
Therefore, the purpose of reliably switching and controlling continuous regeneration of a plurality of independent filter units by one switching valve that rotates smoothly even at high temperatures is achieved.

(1) Three or more valves can be opened and closed with one switching valve, and the branches of a large number of pipes are concentrated, so that the whole can be reduced in size.
(2) Since the switching valve is opened and closed by the cam at the center, a slight error is allowed, a complicated and expensive control unit such as a microcomputer is not required, and the movement operation may be the simplest limit device.
(3) Since the actuator is moved by the cam provided at the central portion near the axis, the capacity of the actuator is small.
(4) Since the operation is performed by the cam provided at the central portion along the axis, even if heat distortion occurs, the rotational movement of the valve disc 13 is smooth.
(5) With this switching valve, the particulate matter (PM) of the entire filter can be sequentially incinerated with electric power for heat-treating one-third or more of the filter section of the entire filter. (6) Switching may be performed after the filter is clogged. Since the pressure is switched in small increments, the pressure loss is small and no load is applied to the engine.
(7) Since pressure loss due to clogging is small, a filter having a finer gap can be used, and the particulate matter removal efficiency increases.
(8) The moving speed of the filter unit and the temperature of the heater can be changed immediately in response to the volume of particulate matter, that is, clogging, and the efficiency is extremely high.
(9) The surface of the valve seat of the switching valve is always cleaned.

As shown in FIGS. 1 and 2, the valve body 11 of the switching valve G is provided at at least one position of a valve disc 13 rotatable along the axis 10 of the substrate 7, and is provided at the center of the valve disc 13. The projection 17 of the downwardly facing serrated cam 16 rotates while abutting on a crown-shaped cam 15 provided upward in the center of the substrate 7 corresponding to the serrated cam 16.
The protrusion 17 moves in the axial direction along the concave portion 21 and the convex portion 22 of the crown-shaped cam 15 while slidingly contacting the crown-shaped cam 15 as shown in FIG. 11 is moved in the axial direction by the amount of R, and the through hole 9 of the branch passage provided in the substrate 7 is opened and closed to open and close the unit space D (the flow path of the exhaust gas to the filter unit 2).
That is, when the valve disc 13 moves in the circumferential direction, the valve body 11 of the switching valve G moves in the circumferential direction with respect to the through hole 9 of the substrate 7, and at the same time, the valve body 11 moves by an R amount in the axial direction. Then, the through hole 9 is closed by the valve body 11.

The crown-shaped cam 15 and the saw-toothed cam 16 are provided with the same number of projections and depressions as shown in the development views of FIGS. The recess 21 when closing the through hole 9 is perpendicular to the axis 10, and the movement to the protrusion 22 when opening is gentle along the gradient.
Since the combination of the crown-shaped cam 15 and the projection 17 of the saw-toothed cam 16 are provided in contact with the central portion of the substrate 7, that is, the shaft core 10, the friction against the contact rotation of the cam is reduced. The capacity of the opening / closing actuator is reduced by the crown-type cam 15 and the saw-tooth cam 16 combined with the shaft core 10 being small and the projection 17 being gently swiveling while abutting along the gradient of the crown-type cam 15. Is small.

However, the movement amount of one filter unit is one pitch of the cams 15 and 16 combined vertically, and is easily and without error determined by a ratchet mechanism (not shown) provided as needed.
That is, this simple cam mechanism allows the valve G to rotate accurately and reliably by a predetermined amount without relying on a complicated mechanism, a high-performance motor, or a microcomputer control unit.

More importantly, since the combined cams 15 and 16 are provided small in contact with the rotating shaft 10, even if thermal distortion occurs in the cams or rotating members due to the heating for the regeneration of the filter unit, there is no effect. There is no danger that the rotation of the valve disc 13 is hindered.
[Example]

A feature of the switching valve G of the present invention is that the valve body 11 of the valve disc 13 that moves in the axial direction while the saw-toothed cam 16 combined around the shaft core 10 rotates along the crown-shaped cam 15. In order to open and close the through hole 9 which is a passage of the exhaust gas, the collection unit A and the incineration regeneration unit B are constituted by the position of the valve body 11 which rotates.
That is, the unit having the valve body 11 is the incineration regeneration unit B, and the portion of the empty frame 12 without the valve body 11 is the collection unit A.
The empty frame 12 of the valve disc 13 has a disc shape disclosed in Japanese Patent Application Laid-Open No. 2001-132431, and may have a variable opening as necessary.

In the filter unit 2 of the embodiment, the substrate 7 of the switching valve G is divided into four equal portions together with the four through holes 9 by the cross-shaped partition plate 8 in the flow path of the exhaust gas. The lower end of the equally-divided cross-shaped partition plate 8 is configured so as to coincide with the axial direction from the end surface of the cross-shaped heat insulating material 3 to form one flow path, that is, the space D of the filter unit 2. I have.
However, the filter unit 2 of the filter 1 has the same configuration as the four units 2-a, 2-b, 2-c and 2-d.
In the embodiment, an example in which the filter is divided into four and the cross-shaped heat insulating material or the cross-shaped compartment plate is used for convenience is described. In addition, the division manner may not be a sector shape as in the embodiment. For example, rectangular shapes may be combined.

  In addition, the rotating portion (valve plate) of the switching valve and the members (saw-toothed cam, substrate) and the like in contact with the present invention prevent smooth rotation from being hindered by heat distortion caused by incineration. It is preferably made of a material having a small coefficient of thermal expansion.

The actuator for moving the valve disc 13 can be driven mechanically continuously or intermittently by a deceleration motor, a rotary cam, a solenoid, a rotary solenoid, a cylinder, a bimetal, or the like.
Before or after the filter, it can be combined with a new or conventionally known particulate matter removing device, catalytic device and the like.
In the embodiment, the particulate matter removal device of the exhaust gas equipped with a diesel engine was described, but the present invention is not limited to this. Land engines using large, small diesel engines, marine engines, cogeneration, and other particulate matter It goes without saying that the present invention can be widely used as a branch circuit of other pipelines, without being limited to the treatment of exhaust gas containing.

  Hereinafter, the present invention will be described in detail with reference to examples, but the description of the same members and the same applications will be omitted.

In this embodiment, as shown in FIG. 1 (c), the filter 1 of the particulate matter removing device is divided into four equal parts to form 2-a, 2-b, 2-c, and 2-d. It is housed in the tongs 5 with the cross-shaped heat insulating material 3 interposed therebetween and the tubular heat insulating material 4 interposed therebetween. The walking body 5 is detachably accommodated in an outer cylinder 6.
The substrate 7 of the switching valve G shown in FIG. 1B is provided with a cross-shaped compartment plate 8 that matches the cross-shaped heat insulating material 3 and a through hole 9 for exhaust gas.
A shaft core 10 and a crown-shaped cam 15 shown in FIG. 1A are provided at the center of the substrate 7, and an elastic body 14, a valve body 11, and an empty frame 12 for sealing the through hole 9 are provided. A valve disc 13 is rotatably provided. The substrate 7 has a case 18.

However, as shown in FIG. 2, a serrated cam 16 having a projection 17 at a part thereof is provided at the center of the valve disc 13, and is installed rotatably with respect to the axis 10 of the substrate 7.
The crown-shaped cam 15 provided along the center axis 10 of the base plate 7 is provided with a concave portion 21 and a convex portion 22 at four positions as shown in a developed view of FIG. The protrusion 17 of the saw-tooth cam 16 provided on the board 13 is slidably moved corresponding to the recesses 21 and 22.
The valve disc 13 is composed of one valve element 11 corresponding to each of the four through holes 9 and one empty frame 12.
That is, when the gear 20 joined to the valve disc 13 is rotated by an actuator (not shown) such as a motor from the drive shaft 24 of the drive gear 23, the projection of the saw-tooth cam 16 of the valve disc 13 is formed. 17 rotates while slidingly contacting the concave portion 21 and the convex portion 22 of the cap-shaped cam 15, and moves in the axial direction against the spring 19 of the shaft core 10. When the projection 17 fits into the recess 21 of the cap-shaped cam 15, the valve body 11 presses the through hole 9 and closes the exhaust gas flow path of the unit B. Then, the filter can be regenerated in the unit B closed by the valve element 11. That is, as shown in FIG. 2, when the projection 17 of the saw-toothed cam 16 of the valve disc 13 comes to the position of the recess 21 of the crown-shaped cam 15, the valve body 11 closes the through hole 9 and the particles in that region are closed. The electric heater 30 which is a heating means for incinerating the particulate matter is energized and heated, and becomes a unit B (heat incineration section) to regenerate the filter. Note that the other three empty frames 12 are units A (collection sections). An elastic body 14 absorbs an error when the valve body 11 closes the through hole 9.

  The electric heater 30 is preferably provided at a position near the end face opening 2s of the filter unit as shown in FIG. The heat-resistant plate 27 in which the heater 30 is housed is provided with a large number of holes 28 so that exhaust gas from the through holes 9 passes through the heater 30 without resistance. The exhaust gas does not concentrate and disperses and reaches the end face opening of the filter.

  Alternatively, a metal honeycomb body that is an electric heating element may be used as the heater 30.

Air required for incineration is introduced from a vent valve 26. That is, when the valve element 11 fits into the recess 21 of the substrate 7 and closes the through hole 9, the ventilation valve 26 at that position is simultaneously pushed and opened, and a necessary amount of air is introduced from outside.
The outside air is introduced by means of an ejector (not shown) provided in the lid 25 provided with the downstream compartment plate 8 '(see JP-A-59-101521), the exhaust gas having passed through the unit B (incineration regeneration). May be sucked.
26 'shows a state where the ventilation valve 26 is closed.

  Alternatively, the combustion air may be introduced by connecting the ventilation valves 26 provided in the respective unit spaces D with one pipe (not shown) and applying a constant pressure from a compressor (not shown) when necessary. .

  The exhaust gas filtered by the filter unit A (collection) is discharged to the atmosphere via a lid 25 provided with a downstream compartment plate 8 '.

  Except for the valve body 11 of the valve disc 13, all are empty frames 12, and in this case, the filter units A corresponding to the three empty frames 12 filter the exhaust gas.

A cleaning brush 29 is provided on a part of the valve disc 13 as needed, and rotates together with the valve disc 13 to remove particulate matter (PM) from the surface of the through hole 9.
The dropped carbon dust is collected separately or incinerated by the heater 30.

  In addition, if the lid 25 and the compartment plate 8 'are removed, and the fork body 5 is removed from the outer cylinder 6 and used upside down, the filter 1 is turned upside down and the filter 1 can be backwashed.

  This embodiment is shown in FIG. In the first embodiment, one filter is equally divided into four filters, and the filters are bundled with the cruciform heat insulating material 3 interposed therebetween. In this example, first, a cruciform partition member 34 is provided by a stainless plate. It is bundled with the cross-shaped heat insulating material 3 interposed therebetween.

FIG. 1 is a partially cutaway explanatory view showing an embodiment of the present invention. (A) shows a valve panel, (B) shows a board, and (C) shows an embodiment of a filter unit. FIG. 2 is a diagram in which a heater, a heat-resistant plate, a vent valve, a drive shaft, and the like are illustrated in the AA line vertical sectional view of FIG. FIG. 3 is an explanatory diagram showing a developed state of a saw-toothed cam and a crown-shaped cam, wherein (a) is in a meshed state and (b) is in a separated state. FIG. 4 is an explanatory diagram of the second embodiment. FIG. 5A is an explanatory view showing a conventional example. FIG. 5B is a vertical sectional view taken along the line AA in FIG. 6A and 6B are explanatory diagrams showing a conventional example. FIG. 7 is an explanatory diagram using two conventional filters. FIG. 8 is an explanatory diagram of a wall flow honeycomb filter.

Explanation of reference numerals

1. Filter A. 1. Collection filter unit Filter unit B. Incineration filter unit (2a, 2b, 2c, 2d)
2c End face of filter Section space 3. Cross-shaped heat insulator E. Filter 4. Cylindrical heat insulating material F. Filter 5. Entourage G. Switching valve 6. Outer cylinder M. Motor 7. Substrate R. 7. Amount of cam movement in the axial direction Compartment plate 8 '. Separator plate (downstream)
9. Through hole 10. Shaft core 11. Valve body 12. Empty frame 13. Valve plate 14. Elastic body 15. Mount type cam 16. Serrated cam 17. Projection 18. Case 19. Spring 20. Gear 21. Recess 22. Convex 23. Drive gear 24. Drive shaft 25. Lid 26. Vent valve 26 '. Closed vent valve 27. Heat-resistant plate 28. Hole 29. Cleaning brush 30. Heater 31. Partition plate 32. Shielding member 33. Exhaust gas introduction opening 34. Partition member

Claims (2)

  The valve element 11 of the switching valve G provided in the pipe flow path is provided at at least one position of a valve disc 13 that is rotatable with respect to the axis 10 of the substrate 7 having three or more through holes 9. The projection 17 of the saw-toothed cam 16 provided downward at the center of the valve disc 13 abuts the crown-shaped cam 15 provided upward at the center of the substrate 7 corresponding to the projection 17. 17 moves in the axial direction while sliding and rotating along the recesses 21 and the protrusions 22 of the crown-shaped cam 15, thereby moving the valve plate 13 and the valve element 11 in the axial direction, and provided on the substrate 7. A switching valve for opening and closing a through hole 9 to a branch passage. One filter for trapping particulate matter is divided into a plurality in the exhaust passage of the diesel engine exhaust gas, and a plurality of filter units are configured by interposing a heat insulating material between the divided filters, or a plurality of filters. A filter comprising a plurality of filter units with a heat insulating material interposed therebetween, and bundling these filter units in parallel to constitute one filter, or removing particulate matter from exhaust gas in which a plurality of branched filter units are provided in parallel In the device,
By providing a heating means for regenerating the filter unit as needed and providing the switching valve G according to claim 1 in the exhaust gas exhaust passage, passages to a plurality of filter units can be sequentially opened and closed. The particulate matter removing device according to claim 1, wherein

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