JP2002097928A - Diesel particulate filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a temperature of combustion of particulates by the function of a catalytic layer provided in a filter, by preventing its durability from lowering down due to a temperature when a substance of the particulates is heated to be incinerated, in this diesel particulate filter device. SOLUTION: A filter 3, 4 is constituted by a layered structure successively laminating a heater 32 consisting of a heat resistant metal wire extended substantially in parallel, a first/second ceramics non-woven fabric 33 and 35 laminating a heat resistant ceramics fiber at random, a catalytic layer 34 arranged between these non-woven fabrics to include a catalyst reducing a temperature of combustion, and a wire net 36 weaving a heat resistant metal wire. The filter 2, 3 is arranged so as to extend from one side to the other side to be directed in a direction crossing with a flow of exhaust gas EG in a squared box-shaped housing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel particulate filter for regenerating a filter by collecting particulate matter contained in exhaust gas discharged from a diesel engine with a filter and heating and burning the collected particulate matter. The present invention relates to a curated filter device.

[0002]

Conventionally, the suspended particles contained in the exhaust gas discharged from the engine carbon, soot, HC, SO _X
As a diesel particulate filter device for removing a particulate material composed of a ceramic or the like, a filter having a structure in which ceramic fibers are laminated and a filter having a honeycomb structure made of porous ceramics are known. This type of filter generally regenerates the filter by heating and burning the particulate material using a heat source when the particulate material is collected and the filter is clogged.

A diesel particulate filter device having a regenerating function disclosed in Japanese Patent Application Laid-Open No. 8-313329 has a self-regenerating function capable of lowering the ignition temperature of particulates and reducing the supply of electric power to a current-carrying wire mesh. The filter is disposed in a pair of exhaust gas passages provided in the exhaust system. An electric wire mesh and an oxidation catalyst wire mesh for lowering the oxidation reaction temperature are arranged on the filter. A shutter valve provided in the exhaust gas passage is operated so as to automatically reduce the flow rate of the exhaust gas in response to an exhaust pressure equal to or higher than a predetermined value. When the ignition temperature of the particulates is lowered by the oxidation catalyst wire mesh and the shutter valve is closed, the particulates easily ignite and burn. Further, the filter can be manufactured by laminating felt-like ceramic fiber laminated members, pressing both sides of the laminated member with a heat-resistant iron wire mesh containing Ni, Cr, or the like, and forming the filter into a predetermined shape. The filter can be formed into a shape having a large surface area by being folded into a pleated shape with a ceramic fiber material, but can also be formed into a cylindrical shape such as a cylindrical shape, a flat plate shape, or a wavy shape.

[0004]

When the particulate matter collected by the filter is heated and incinerated in order to regenerate the filter in the diesel particulate filter device, the ambient temperature around the filter is raised to a certain temperature. I have to do it. Particulate substances emitted from diesel engines is a particulate material containing unburnt products, the constituents of carbon of about 50%, HC is about 25%, and other SO _X, HC
About 25% of harmful compounds containing. The combustion temperature of carbon in these constituents is said to be about 600 ° C. Unless the filter temperature and its ambient temperature are raised to this temperature, the carbon will not ignite and burn.

[0005] However, in the diesel particulate filter device, if the filter and its ambient temperature are repeatedly raised to the combustion temperature of carbon in order to heat and incinerate the particulate matter collected by the filter, deterioration of the filter is accelerated. There is a problem that the durability of the filter is reduced. If the filter is made of a material such as a metal or ceramic, for example, if the temperature of the filter and its ambient temperature exceeds 900 ° C to 1000 ° C,
The filter deteriorates rapidly, and its durability rapidly decreases.

[0006] The filter used in the conventional diesel particulate filter device is formed of a ceramic fiber material and is formed into a shape having a large surface area by being folded in a cylindrical and pleated shape. During combustion, the temperature of the filter and its atmosphere rises, and the raised temperature causes thermal deformation of the pleated cylinder. To maintain its shape, the folded part of the pleated filter must be reinforced with heat-resistant ceramics. Must
Further, since the filter is cylindrical, the arrangement in the housing is complicated, the number of parts of the filter is increased, and the manufacturing cost is increased.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and a filter for collecting particulate matter contained in exhaust gas is constituted by a ceramic nonwoven fabric, a heat-resistant metal wire mesh or the like. In this case, a layer containing a catalyst such as Ni, Co, Pt or Pd is embedded in the filter to reduce the burning temperature of the particulate matter in order to reduce the burning temperature of the particulate matter collected by the filter. And a diesel particulate filter device in which the filter itself is not easily deformed by heat, has a simple bellows shape with an increased exhaust gas passage area, and is configured so that the filter itself can be easily disposed in the housing. It is to be.

According to the present invention, a particulate matter contained in exhaust gas discharged from an engine is collected by a filter disposed in an exhaust pipe, and the particulate matter collected by the filter is heated and incinerated. In the filter device, the filter includes a heater made of a heat-resistant metal wire, a first ceramic nonwoven fabric in which heat-resistant ceramic fibers are randomly stacked, a catalyst layer containing a catalyst for reducing the burning temperature of the particulate matter, The present invention relates to a diesel particulate filter device having a laminated structure in which a second ceramic nonwoven fabric in which conductive ceramic fibers are randomly laminated and a wire mesh in which heat-resistant metal wires are braided are sequentially laminated.

The filter having the laminated structure is arranged such that the heater is located upstream of the flow of the exhaust gas and the wire mesh is located downstream.

The heat-resistant metal wires constituting the heater extend substantially in parallel with the first ceramic nonwoven fabric, respectively. Further, in the heater, the heat-resistant metal wires are respectively connected in parallel.

The first and second ceramic nonwoven fabrics are
It is made of heat-resistant ceramics such as silicon nitride, silicon carbide, and alumina. Further, the first and second ceramic nonwoven fabrics are formed of fibers having a length of about 30 mm to 100 mm.

In the catalyst layer, a metal powder composed of Ni, Co, Pt and / or Pd is dispersed in a thin layer of a wire mesh or nonwoven fabric based on Ni.

[0013] The filter is bent in a bellows shape to increase a passage area where the exhaust gas contacts.

When the filter is incorporated in a diesel particulate filter device, the filter is
A rectangular box-shaped housing is provided so as to extend from one surface of the housing to the opposite surface facing the direction orthogonal to the flow direction of the exhaust gas.

The housing is composed of one piece, and an exhaust gas inlet side of the filter is formed with a divided exhaust gas inlet, and the exhaust gas inlet is provided with an opening / closing shutter, respectively, and the opening / closing shutter is controlled by a controller. Opening / closing is controlled in response to the operating state of the engine.

Further, an exhaust gas inlet is formed on the one surface of the housing to which one end of the filter is attached, and the filter is provided on the inlet side of the housing to allow the exhaust gas to flow evenly into the filter. Are arranged in the housing such that the cross-sectional area of the passage is large and the cross-sectional area of the passage at the back of the housing is small.

In this diesel particulate filter device, the housing has exhaust gas inlets disposed opposite to each other in a switching passage connected to the exhaust pipe, and the filters are disposed in the housing, respectively. Is provided with an exhaust gas switching valve which is switched to open one of the exhaust gas inlets and close the other to supply the exhaust gas to the filter, and to an exhaust gas outlet formed respectively in the housing. Is connected to the outlet side exhaust pipe. Further. The diesel particulate filter device includes a controller that controls the switching of the exhaust gas switching valve and the energization of the heater in response to the amount of the particulate matter collected by the filter.

The diesel particulate filter device may further include a gas supply pipe which is opened to an upstream side of the filter in the housing to supply the exhaust gas or the air into the housing, and a gas supply pipe for regenerating the filter. A gas switching valve provided in the gas supply pipe for supplying the exhaust gas or air into one of the housings through a supply pipe, and the exhaust gas or air in the housing through the gas supply pipe. It has a blower pump operated to supply the air. The controller controls the operation of the blower pump and the switching operation of the gas switching valve in response to regeneration of the filter.

The heater constituting the filter and the metal layer forming the catalyst layer are formed in such a shape as to be able to conduct electricity, and the particulate matter is easily ignited by a catalytic effect.

The heater constituting the filter includes N
It is composed of an i-line and a metal powder composed of Co, Pt and / or Pd dispersed on the Ni line.

This diesel particulate filter device is constructed as described above, so that when the particulate matter collected by the filter is heated and incinerated, the first particulate matter is removed.
Since there is a catalyst layer for reducing the burning temperature between the second ceramic nonwoven fabric and the second ceramic nonwoven fabric, the burning temperature of the particulate material is reduced by about 100 ° C. to 150 ° C.
It ignites and burns at 50 ° C to 500 ° C, making it possible to significantly increase the durability of the filter. By the way, metal,
Materials such as ceramics rapidly deteriorate in durability when the temperature exceeds 900 ° C. to 1000 ° C. However, when used at 900 ° C. or less, the durability time becomes extremely long, and there is no deterioration of the material and the life is extended. Become. In this diesel particulate filter device, the particulate matter is burned while the temperature of the filter is suppressed at about 500 ° C., so that the temperature range up to the endurance limit of the filter is 400 ° C. (=
900 ° C.-500 ° C.), and a longer filter life can be achieved.

The filter incorporated in the diesel particulate filter device has a simple shape that is simply bent in a bellows shape in order to increase a passage area where exhaust gas contacts, so that it is difficult to be thermally deformed. The bellows shape can be maintained, and a large passage area can be maintained for a long period of time. The housing that incorporates the filter is
Since the filter is formed in a rectangular box shape, when the filter is incorporated in the housing, the filter can be extremely easily arranged so as to extend from one surface of the housing to the other opposite surface in a direction crossing the flow of the exhaust gas. The structure for fixing the filter to the housing is simplified, and further, the diesel particulate filter device can greatly reduce the number of parts and can greatly reduce the manufacturing cost as compared with the conventional pleated cylindrical filter.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a diesel particulate filter device according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of a diesel particulate filter device according to the present invention, in which a filter is provided in a housing, FIG. 2 is a schematic perspective view showing a filter in a region A of FIG. FIG. 3 is an exploded perspective view for explaining the structure of the filter, and FIG. 4 is a schematic sectional view showing a specific embodiment of the diesel particulate filter device according to the present invention.

As shown in FIG. 1, this diesel particulate filter device captures particulate matter composed of carbon, soot, HC, SO _{X and the} like contained in exhaust gas EG discharged from the engine by filters 3 and 4. The particulate matter collected by the filters 3 and 4 is heated and incinerated to regenerate the filters 3 and 4.
The housings 1 and 2 in which the filters 3 and 4 are provided are arranged between the inlet-side exhaust pipe 5 and the outlet-side exhaust pipe 6.
In order to increase the surface area in contact with the exhaust gas EG, the filters 3 and 4 are bent in bellows as a whole, extend in the longitudinal direction, and are disposed in the housings 1 and 2.

The filters 3 and 4 are bent in a bellows shape in order to increase the passage area where the exhaust gas EG contacts. Filters 3, 4 are rectangular box-shaped housings 1, 2,
The housing is arranged so as to extend from one surface of the housing to the opposite surface facing the flow direction of the exhaust gas EG. In the filters 3 and 4, the peak of the bellows fold is the exhaust gas E.
It is directed parallel to the same direction along the flow of G,
Also, the valleys of the bellows folds are directed parallel to the same direction along the flow of the exhaust gas EG. Exhaust gas inlets 13 and 14 (FIG. 4) are formed on one side of the housings 1 and 2 to which one ends of the filters 3 and 4 are attached. In order to make it flow evenly, the inlet side 13 of the housings 1 and 2
F and 14F are arranged in the housings 1 and 2 such that the cross-sectional area of the passage is large, and the cross-sectional areas of the passages 13R and 14R on the rear side of the housings 1 and 2 are small. The exhaust gas EG is
The particulate matter contained in the exhaust gas EG is collected by the filters 3 and 4 when being sent from the inlet side exhaust pipe 5 to the filters 3 and 4 and passing through the filters 3 and 4. The purified exhaust gas EG from which the particulate matter has been removed is discharged from the outlet side exhaust pipe 6.

As shown in FIGS. 2 and 3, the filters 3 and 4 are formed by randomly laminating a heater 32 made of a heat-resistant metal wire having electrode terminals 25 and 26 at both ends and a heat-resistant ceramic fiber. The first ceramic nonwoven fabric 33,
A layered structure in which a catalyst layer 34 containing a catalyst for reducing the burning temperature of particulate matter, a second ceramic nonwoven fabric 35 in which heat-resistant ceramic fibers are randomly stacked, and a wire mesh 36 in which heat-resistant metal wires are woven are sequentially stacked. Structured. The filters 3 and 4 having a laminated structure are arranged in the housings 1 and 2 such that the heater 32 is located on the upstream side with respect to the flow of the exhaust gas EG, and the wire mesh 36 is located on the downstream side to prevent the scattering of the ceramic fibers. Are arranged.

The catalyst layer 34 is obtained by dispersing a metal powder composed of cobalt (Co), platinum (Pt) and / or palladium (Pd) in a thin layer of a wire mesh or nonwoven fabric based on a nickel (Ni) wire. It is configured to be carried in a state. Further, an electrode terminal 44 (FIG. 3) may be provided on the wire mesh or thin plate of the catalyst layer 34, and the wire mesh or thin plate may be used as a heater when the filters 3 and 4 are regenerated. The metal material of the heater 32, the catalyst layer 34 and the wire mesh 36 is the exhaust gas E
When the material is such as to corrode in contact with G, it can be coated with a material such as a corrosion-resistant ceramic.

The heaters 3 constituting the filters 3 and 4
The metal layer that forms the catalyst layer 2 and the catalyst layer 34 is configured to be able to conduct electricity, and is configured to facilitate the ignition of the particulate material by the catalytic effect. The heaters 32 constituting the filters 3 and 4 are composed of a Ni wire and a metal powder made of cobalt, platinum, and / or palladium dispersed on the Ni wire.

As shown in FIGS. 2 and 3, the heat-resistant metal wire constituting the heater 32 is made of a first ceramic nonwoven fabric 33.
However, it is not always necessary that they be parallel, and in some cases, they may be in contact with each other. The heater 32 has a heat-resistant metal wire connected to the electrode terminals 25 and 26 in parallel. The heat-resistant metal wire of the heater 32 may be laminated on the first ceramic nonwoven fabric 33 so as to extend substantially in parallel from one end to the other end. In some cases, even if the heat-resistant metal wires of the adjacent heaters 32 are in contact with each other, the total resistance does not change when a voltage is applied between the electrodes, so that they are not necessarily arranged in parallel. .

First and second ceramic nonwoven fabrics 33, 3
5 is silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC),
It is made of a heat-resistant ceramic such as alumina (Al ₂ O ₃ ). Further, the first and second ceramic nonwoven fabrics 33 and 35 are formed of ceramic fibers having a length of about 30 mm to 100 mm.

This diesel particulate filter device is specifically configured as shown in FIG. This diesel particulate filter device
An inlet-side exhaust pipe 5 and an outlet-side exhaust pipe 6 are connected to and incorporated into an exhaust pipe from which exhaust gas EG generated by the engine is discharged. Exhaust gas inlets 13 and 14 of the housings 1 and 2 are arranged in a switching passage 15 connected to the inlet side exhaust pipe 5 so as to face each other. Housing 1, 2
Are fixed to each other in a predetermined shape by a frame 29 or the like with the switching passage 15 interposed therebetween. The filters 3 and 4 are arranged in the housings 1 and 2, respectively. The switching passage 15 has a switchable exhaust gas switching valve 12 driven by an actuator 10 to open one of the exhaust gas inlets 13 and 14 and supply the exhaust gas EG to the filters 3 and 4 and close the other. The actuator 10 and the exhaust gas switching valve 12 are fixed to the frame 29 and the like. An outlet-side exhaust pipe 6 is connected to exhaust gas outlets 16 and 17 formed in the housings 1 and 2, respectively. A pressure sensor 3 for detecting the pressure of the exhaust gas for detecting the amount of particulate matter collected by the filters 3 and 4 is provided on the inlet side exhaust pipe 5 and the outlet side exhaust pipe 6.
0 and 31 are provided respectively.

Further, in this diesel particulate filter device, exhaust gas EG or air is supplied into the housings 1 and 2 through gas supply ports 27 and 28 opened on the upstream side of the filters 3 and 4 in the housings 1 and 2, respectively. Gas supply pipes 7, 8 for supplying exhaust gas EG or air to one of the housings 1, 2 through the gas supply pipes 7, 8 at the time of regeneration of the gas supply pipes 7, 8, and the filters 3, 4
A blower pump 9 that is operated to supply exhaust gas EG or air into the housings 1 and 2 through the gas switching valves 21 and 22 and the gas supply pipes 7 and 8 that are driven by actuators 11A and 11B provided in the housing 1. Having.

The diesel particulate filter device also includes temperature sensors 18 and 19 extending in the direction perpendicular to the surfaces of the filters 3 and 4 to detect the temperatures of the filters 3 and 4 during regeneration of the filters 3 and 4. I have. The controller 20 controls the energization of the heater 32 in response to the temperature detected by the temperature sensors 18 and 19 and controls the operation of the motor that drives the blower pump 9 in order to prevent the filters 3 and 4 from overheating. Thus, the supply amount of the exhaust gas EG or the air into the housings 1 and 2 is adjusted. That is, the controller 20 controls the rotation speed of the motor that drives the blower pump 9 in response to the operating state of the engine such as the engine speed detected by the rotation sensor 23 and the engine load detected by the load sensor 24. During regeneration of the filters 3 and 4, for example, the controller 20 increases the number of rotations of the motor when the load of the engine is high and sends a large amount of exhaust gas EG or air gas to the filters 3 and 4; Control is performed to reduce the number and feed a small amount of gas to the filters 3 and 4.

The controller 20 includes pressure sensors 30, 3
1 to detect the pressure ratio of the pressure detected by
If the force ratio is larger than the power ratio, the
That the amount of particulate matter reaches a predetermined amount
Recognizes and responds to the pressure ratio to switch the exhaust gas switching valve 12
Control to switch, then deposit on filter 3 or 4
To incinerate the burned particulate matter
Control to energize the heater 32. In addition, the controller 20
Operates the blower pump 9 in response to regeneration of the filters 3 and 4.
Operation and switching operation of the gas switching valves 21 and 22.
The operation of the tutors 11A and 11B is controlled. In addition,
The controller 20 detects the engine detected by the rotation sensor 23.
Engine speed, engine load detected by load sensor 24, etc.
Pressure sensors 30, 31 in response to the operating state of the engine
Pressure P detected by₁, P _TwoPressure ratio (P_Two/ P
₁) To calculate the appropriate amount of particulate matter collected.
Calculation to control when the exhaust gas switching valve 12 is switched,
The exhaust gas EG or empty air sent into the housings 1 and 2
Control the operation of the blower pump 9 to adjust the air flow
You.

This diesel particulate filter device is configured as described above, and operates as follows. Exhaust gas EG generated by the engine flows into the switching passage 15 through the inlet-side exhaust pipe 5. As shown in FIG. 4, in the switching passage 15, first, the exhaust gas switching valve 12
Assuming that the exhaust gas inlet 13 is opened and the exhaust gas inlet 14 is closed, the exhaust gas EG is sent into the housing 1 from the switching passage 15 through the exhaust gas inlet 13 as shown by an arrow. Since the filter 3 is provided in the housing 1, the exhaust gas EG
, And is discharged from the exhaust gas outlet 16 to the outlet side exhaust pipe 6. When the exhaust gas EG passes through the filter 3, the particulate matter contained in the exhaust gas EG is collected by the filter 3. When particulate material is deposited is trapped in the filter 3, the inlet-side exhaust pipe 5 the pressure P ₂ of the exhaust gas EG flowing rises, the pressure P ₁ of the exhaust gas EG flowing the outlet side exhaust pipe 6 is lowered. If the outlet side exhaust pipe 6 is in atmospheric release state, the pressure P ₁ is also the atmospheric pressure as the normal drop. These pressures P ₁ , P
₂ is detected by the pressure sensors 30, 31 and electric means. These pressures P ₁ and P ₂ are controlled by the controller 20.
Is input, the pressure ratio P ₂ / P ₁ is calculated. When the pressure ratio P ₂ / P ₁ becomes equal to or more than a predetermined value, the controller 20 issues a command for the following processing assuming that a predetermined amount of particulate matter has been collected in the filter 3.

The controller 20 includes the actuator 10
Is driven to switch the exhaust gas switching valve 12, the exhaust gas inlet 13 is closed, and the exhaust gas inlet 14 is opened. Therefore, the exhaust gas EG flowing from the inlet-side exhaust pipe 5 into the switching passage 15 is sent from the exhaust gas inlet 14 to the housing 2, and the filter 4 is provided in the housing 2. The exhaust gas is purified by passing through the filter 4 and discharged from the exhaust gas outlet 17 to the outlet side exhaust pipe 6. Further, the controller 20 energizes the heater 32 incorporated in the filter 3 through the electrode terminal 25 to heat and incinerate the particulate matter collected by the filter 3, thereby heating the filter 3 and its atmosphere. Next, the controller 20 operates the actuators 11A and 11B, opens the gas switching valve 21 of the gas supply pipe 7, closes the gas switching valve 22 of the gas supply pipe 8, and sets the air pump 9
Operate. The operation of the blower pump 9 causes the exhaust gas E
G or air is supplied into the housing 1 from the gas supply port 27 through the gas supply pipe 7. As the exhaust gas EG supplied to the housing 1 by the blower pump 9, it is preferable to use purified exhaust gas flowing through the outlet side exhaust pipe 6.

When the particulate matter collected in the filter 3 is supplied with exhaust gas EG containing oxygen or air through the gas supply pipe 7 into the housing 1. Filter 3
Is heated by a heater 32 provided in the heater and ignited and burnt, and is incinerated by heating. At this time, the combustion temperature of the particulate matter is suppressed low by the catalyst layer 34 provided on the filter 3, and the filter 3 and its atmosphere are detected by the temperature sensor 18, and when the temperature reaches a predetermined temperature or higher, the heater 32 is turned off. Then, the heating by the heater 32 is stopped, and the incineration is performed by the combustion propagation of the particulate matter. The filter 3 is heated and incinerated to regenerate the particulate matter, and enters a standby state for the next particulate matter collecting process. On the other hand, the exhaust gas EG is purified by the filter 4. However, the particulate matter contained in the exhaust gas EG is deposited on the filter 4 in a predetermined amount or more, so that the same regeneration processing as that of the filter 3 is performed. The exhaust gas EG is purified by the regenerated filter 3. In this diesel particulate filter device, the above exhaust gas treatment process is repeated, and the exhaust gas EG discharged from the engine is continuously purified.

Next, another embodiment of the diesel particulate filter device according to the present invention will be described with reference to FIG. In this embodiment, the housing 1A is composed of one piece and is disposed between the inlet-side exhaust pipe 5A and the outlet-side exhaust pipe 6A. An exhaust gas inlet 39 is formed on the exhaust gas inlet side of the housing 1A to which the inlet exhaust pipe 5A is connected. The exhaust gas inlet 39 is provided with opening and closing shutters 37 and 38, respectively. The opening and closing shutters 37 and 38 are respectively controlled to open and close by the controller 20A in response to the engine operating state. For example, when the engine load is high and the exhaust gas temperature is high, the controller 20 </ b> A
When the engine load is low, one of the open / close switches 40 or 41 is turned off through the line 42 to keep the open / close shutter 37 or 38 open, and the other open / close switch 41 or 41 is opened. 40
Is turned off through the line 43 and the shutter 38 is opened and closed.
Or, control for closing 37 is performed. Opening and closing shutter 37,
38 is attached to the housing 1A and / or the filter 3A. The filter 3A is substantially the first
The filter has the same structure as the filters 3 and 4 of the embodiment. In this embodiment, the opening / closing shutter 38 or 37 is controlled to be opened and closed by the controller 20A according to the temperature and the flow rate of the exhaust gas EG, so that the exhaust gas EG can be appropriately purified.

[0039]

As described above, the diesel particulate filter device according to the present invention has a very compact structure because the housing in which the filter is disposed has a rectangular shape, so that not only new vehicles but also existing vehicles can be used. The muffler mounting structure or the muffler can be easily mounted on the vehicle as a muffler. In addition, since the filter has a catalyst layer that suppresses the combustion temperature in the ceramic fiber, the particulate matter collected by the filter can be heated and incinerated at a low temperature. It is possible to prevent the filter from deteriorating, prolong the life of the filter, and increase the durability. Further, since the filter is provided with a heater extending substantially parallel to the entire surface of the ceramic fiber, the particulate matter collected by the filter is uniformly heated and incinerated without being locally heated. Also, even if the metal wire of a heater comes into contact with the metal wire of another heater due to heating, since the heaters are connected in parallel, the total resistance does not substantially change and the particulate matter can be smoothly removed. It can perform the function of heating and incineration.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a diesel particulate filter device according to the present invention, showing a state in which a filter is provided in a housing.

FIG. 2 is a schematic perspective view showing a filter in a region indicated by reference numeral A in FIG.

FIG. 3 is an exploded perspective view illustrating a structure of a filter.

FIG. 4 is a schematic sectional view showing a specific embodiment of a diesel particulate filter device according to the present invention.

FIG. 5 is a schematic explanatory view showing another embodiment of the diesel particulate filter device according to the present invention, showing a state in which the filter is disposed in a housing.

[Explanation of symbols]

 1, 2, 1A Housing 3, 4, 3A Filter 5, 5A Inlet-side exhaust pipe 6, 6A Outlet-side exhaust pipe 7, 8 Gas supply pipe 9 Blast pump 10, 11A, 11B Actuator 12 Exhaust gas switching valve 13, 14 Exhaust Gas inlet 13F, 14F Inlet side 13R, 14R Back side 15 Switching passage 16, 17 Exhaust gas outlet 20, 20A Controller 21, 22 Gas switching valve 30, 31, Pressure sensor 32 Heater 33 First ceramic nonwoven fabric 34 Catalyst layer 35 Second ceramic Non-woven fabric 36 Wire mesh 37, 38 Opening / closing shutter 39 Entrance

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01N 3/02 341 F01N 3/02 341H 341J 341R B01D 39/14 B01D 39/14 B 39/20 39/20 DA 53/94 F01N 3/10 A F01N 3/10 3/24 E 3/24 3/32 301B 3/32 301 B01D 53/36 103C F term (reference) 3G090 AA02 AA03 BA04 CA01 CA04 CB14 CB18 CB24 DA04 DA13 DA18 DA20 EA01 3G091 AA18 AB02 BA00 CA03 EA00 EA01 EA03 EA18 4D019 AA01 BA02 BA05 BB03 BC07 CA02 CB06 DA02 4D048 AA14 AB01 BA30X BA30Y BA31X BA31Y BA37X BA37Y BA38X BA38Y BB04 CC05 CC05 CD08

Claims (15)

[Claims] 1. A diesel particulate filter device for collecting particulate matter contained in exhaust gas discharged from an engine by a filter arranged in an exhaust pipe and heating and burning the particulate matter collected by the filter. In the above, the filter may include a heater made of a heat-resistant metal wire, a first ceramic nonwoven fabric in which heat-resistant ceramic fibers are randomly laminated, a catalyst layer containing a catalyst for reducing the burning temperature of the particulate matter,
2nd heat-resistant ceramic fibers randomly laminated
A diesel particulate filter device having a laminated structure in which a ceramic non-woven fabric and a wire mesh in which heat-resistant metal wires are woven are sequentially laminated. 2. The filter according to claim 1, wherein the filters are arranged such that the heater is located upstream of the flow of the exhaust gas and the wire mesh is located downstream. Diesel particulate filter device. 3. The diesel particulate filter device according to claim 1, wherein the heat-resistant metal wires constituting the heater extend substantially in parallel with the first ceramic non-woven fabric, respectively. . 4. The diesel particulate filter device according to claim 3, wherein the heat-resistant metal wires are connected in parallel to the heater. 5. The diesel particulate filter device according to claim 1, wherein said first and second ceramic nonwoven fabrics are made of heat-resistant ceramics such as silicon nitride, silicon carbide, and alumina. 6. The diesel particulate filter device according to claim 1, wherein the first and second ceramic nonwoven fabrics are formed from fibers having a length of about 30 mm to 100 mm. 7. The catalyst layer comprises Ni, Co, Pt and / or Pt.
2. The diesel particulate filter device according to claim 1, wherein metal powder composed of Pd or Pd is dispersed in a thin layer of a wire mesh or nonwoven fabric based on Ni. 8. The diesel particulate filter device according to claim 1, wherein the filter is bent in a bellows shape so as to increase a passage area where the exhaust gas contacts. 9. The filter is provided on a rectangular box-shaped housing so as to extend from one surface of the housing to the other surface facing the direction orthogonal to the flow direction of the exhaust gas. The diesel particulate filter device according to claim 1, wherein 10. The housing comprises one piece,
An exhaust gas inlet side of the filter is formed with a divided exhaust gas inlet, and an open / close shutter is provided at the exhaust gas inlet, and the open / close shutter is respectively controlled by a controller in response to an engine operating state. The diesel particulate filter device according to claim 9, wherein: 11. An exhaust gas inlet is formed in the one surface of the housing to which one end of the filter is attached,
The filter is arranged in the housing such that the passage cross-sectional area on the inlet side of the housing is large and the passage cross-sectional area on the back side of the housing is small in order to allow the exhaust gas to flow evenly into the filter. The diesel particulate filter device according to claim 9, wherein: 12. The exhaust gas inlet of the housing is disposed in a switching passage connected to the exhaust pipe so as to face each other. The filters are respectively disposed in the housing. An exhaust gas switching valve, which is switched to open one of the exhaust gas inlets and close the other to supply exhaust gas, is provided, and an exhaust gas outlet formed at the housing is provided with an outlet exhaust pipe. 10. A controller which is connected and controls the switching of the exhaust gas switching valve and the energization to the heater in response to the amount of the particulate matter collected by the filter. 2. The diesel particulate filter device according to item 1. 13. A gas supply pipe which opens to an upstream side of the filter in the housing and supplies the exhaust gas or the air into the housing, or passes through the gas supply pipe at the time of regeneration of the filter. A gas switching valve provided on the gas supply pipe to supply the exhaust gas or air into the housing, and an exhaust gas or air supplied to the housing through the gas supply pipe. 13. The diesel particulate filter device according to claim 12, further comprising a blower pump, wherein the controller controls operation of the blower pump and switching operation of the gas switching valve in response to regeneration of the filter. 14. The heater according to claim 1, wherein the heater and the metal layer forming the catalyst layer are configured to be energizable, and the particulate matter is easily ignited by a catalytic effect. 2. The diesel particulate filter device according to 1. 15. The heater according to claim 1, wherein the heater constituting the filter comprises a Ni wire and a metal powder composed of Co, Pt and / or Pd dispersed on the Ni wire. 2. The diesel particulate filter device according to item 1.