JP2004263594A - Diesel particulate filter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diesel particulate filter device, provided with a noise reduction structure or a structure of making flow uniform disposed on the upstream of a particulate filter and an oxidation catalyst, and exhibiting the performance of the structure, the oxidation catalyst and the particulate filter to thereby treat the exhaust emission efficiently in a saved space. <P>SOLUTION: In this diesel particulate filter device, a perforated pipe 23 for making uniform the flow of exhaust emission taken in the interior of a front shell 11, perforated plugs 24, 25, perforated baffle plate 27, and a baffle plate 26 are disposed in front of an oxidation catalyst 31 in the interior of the front shell 11. The surface treatment using material having heat resistance to the exhaust temperature and higher incompatibility to oil than the respective shells is applied to the perforated pipe 23, the perforated plugs 24, 25, the perforated baffle plate 27 and the baffle plate 26. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to the technical field of a diesel particulate filter device that collects and processes particulate matter (PM) contained in exhaust gas from a diesel engine or the like.
[0002]
[Prior art]
In conventional diesel particulate filter devices, an oxidation catalyst is arranged upstream of the particulate filter inside the device, and by lowering the combustion temperature of the particulates, the particulate matter collected by the particulate filters is burned and subjected to combustion processing. The filter is reproduced (for example, see Patent Document 1).
[0003]
Further, there is a catalyst device in which a silencing structure is provided before and after the catalyst (for example, see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-2003-3833 (pages 2 to 10, FIG. 10)
[0005]
[Patent Document 2]
JP 2001-271628 A (Page 3-4, FIG. 1)
[0006]
[Problems to be solved by the invention]
The present inventors have arranged an oxidation catalyst in front of a particulate filter inside the apparatus and further provided a plurality of small holes in front of the oxidation catalyst. We have devised a diesel particulate filter device equipped with a structure that makes the flow of air uniform.
However, in this diesel particulate filter device, the following problems have been technical issues.
[0007]
When unburned fuel enters the diesel particulate filter device at the same time as the soot, it has adhered and deposited on the surface of the components of the silencing structure or the structure that homogenizes the flow provided in the device.
When this deposit grows and grows, it separates from the surface and adheres to the rear surface of the oxidation catalyst or the particulate filter, blocking the passage of the oxidation catalyst or the particulate filter. , Increasing the ventilation resistance, leading to lower fuel efficiency and driving performance.
In addition, since the small holes provided in the silencing structure or the structure for homogenizing the flow are closed, the silencing effect or the performance of the uniform flow cannot be sufficiently obtained.
[0008]
To solve this problem, as a means for ensuring a uniform flow, it is conceivable to provide a structure having a gentle taper without providing a structure with a uniform flow, but since the length of the inlet side container is required to be considerably long, Vehicle mountability will deteriorate.
[0009]
Further, in order to effectively reduce the exhaust noise, it is effective to provide a silencer in the exhaust system so as to cut off air column resonance of the exhaust system and not resonate with exhaust pulsation from the engine. However, due to the above-described problems, a muffler cannot be provided on the upstream side of the oxidation catalyst and the particulate filter.
[0010]
The present invention has been made in view of the above problems, and its object is to provide an oxidation catalyst, a silencing structure or a structure for homogenizing the flow upstream of the particulate filter, It is an object of the present invention to provide a diesel particulate filter device in which the performance of a structure, an oxidation catalyst, and a particulate filter is exhibited, and exhaust gas treatment can be efficiently performed in a small space.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, both ends of the cylindrical container body are reduced in diameter to form a connection port that is connected in the middle of the exhaust system of the engine to collect particulate matter in the exhaust gas. A filter for reburning with exhaust gas is provided inside the container body, and an oxidation catalyst for making particulate matter in the exhaust gas easily reburnable is provided in front of the filter inside the container body. In a diesel particulate filter device in which a structure for equalizing the flow is provided in front of the oxidation catalyst inside the container body, a surface treatment of a material that has heat resistance to exhaust gas temperature and has a higher affinity for oil than the container body. The means is characterized in that it is applied to the structure inside the apparatus book.
[0012]
According to the second aspect of the present invention, there is provided a filter for reducing the diameter of both ends of the cylindrical container body and forming a connection port for connection in the middle of the exhaust system of the engine, collecting particulate matter in the exhaust gas and reburning the exhaust gas. An oxidation catalyst is provided inside the container body to make the particulate matter in the exhaust gas easily reburnable.The oxidation catalyst is provided in front of the filter inside the container body, and the structure that silences the exhaust gas taken into the container body through the connection port is provided. In the diesel particulate filter device installed in front of the oxidation catalyst inside the main body, a surface treatment of a material that has heat resistance to the exhaust gas temperature and has higher affinity for oil than the container body is applied to the structure inside the main unit. It is a means characterized by having done.
[0013]
According to a third aspect of the present invention, there is provided the means, wherein the structure has a large number of small holes, and the surface treatment is to apply molybdenum disulfide or graphite.
[0014]
Function and Effect of the Invention
According to the first and second aspects of the present invention, the structure portion has heat resistance, and is subjected to a surface treatment having high affinity for oil, so that the oil contained in the exhaust gas hardly adheres to the surface of the structure portion. Become. If the oil does not adhere, soot that accumulates on the oil does not easily adhere, and soot does not accumulate.
[0015]
According to the third aspect of the present invention, the air flow of the exhaust gas is changed in many directions by a large number of small holes to make the flow uniform or mute, and the surface is treated by applying molybdenum disulfide or graphite. In order to prevent the accumulation of soot that closes the small holes.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments for realizing the diesel particulate filter device of the present invention will be described based on embodiments corresponding to the first, second, and third aspects of the present invention.
[0017]
(Example)
[0018]
First, the configuration will be described.
FIG. 1 is a sectional view showing a diesel particulate filter device according to an embodiment. 1 is a DPF device (diesel particulate filter device), 11 is a front shell, 12 is a center shell, 13 is a rear shell, 14 is a flange portion connecting the front shell and the center shell, 15 Is a flange portion connecting the center shell and the rear shell, 2 is a diffusion chamber, 21 is a front flange (connection port), 22 is a curved end plate, 23 is a perforated pipe, 24 and 25 are perforated plugs, and 26 is a baffle plate. 27, a perforated baffle plate, 3 a catalyst chamber, 31 an oxidation catalyst, 32 a catalyst holding mat, 4 a filter chamber, 41 a particulate filter (filter), 42 a filter holding mat, 5 a downstream connection chamber , 51 are rear flanges (connection ports), 6 is a control sensor, and A is a surface treatment range.
[0019]
In the DPF device 1 of the present embodiment, as shown in FIG. 1, a portion enlarged from a small-diameter front flange 21 connected to an exhaust system is provided at a front end portion of a front shell 11 with a curved end plate 22. An oxidation catalyst 31 is provided while the outer periphery is held by a catalyst holding mat 32 with the rear part as a catalyst chamber 3. The space in front of the oxidation catalyst 31 inside the front shell 11 is defined as the diffusion chamber 2, and a perforated pipe 23 that guides the exhaust gas from the front flange 21 to the inside, and a flow of the exhaust gas that travels straight along the perforated pipe 23 is appropriately adjusted. Perforated plugs 24 and 25 for directing in other directions, baffle plate 26 for regulating the flow of air in diffusion chamber 2, and a uniform flow in diffusion chamber 2, which has become a multi-directional flow, is provided. To provide a perforated baffle plate 27 leading to the oxidation catalyst 31.
As described above, the cylindrical central shell 12 is attached to the rear portion of the front shell 11 provided with the diffusion chamber 2 and the catalyst chamber 3 by the flange portion 14, and the inside of the central shell 12 is used as the filter chamber 4.
In the filter chamber 4, a particulate filter 41 is provided by a filter holding mat. A control sensor 6 for detecting the exhaust gas temperature is provided between the oxidation catalyst 31 and the particulate filter 41.
Further, to the central shell 12, a rear shell 13 having a rear end 51 provided with a cylindrical and reduced diameter so as to connect a rear end to an exhaust system is connected by a flange portion 15. The inside of the rear flange 51 is referred to as a downstream connection chamber 5.
The front shell 11, the center shell 12, and the rear shell 13 are made of heat-resistant and corrosion-resistant SUS material.
[0020]
In this embodiment, as shown in FIG. 1, the inside of the diffusion chamber 2 is subjected to a surface treatment range A to perform a surface treatment.
This surface treatment is performed in the following manner. First, the perforated pipe 23, the perforated plugs 24 and 25, the baffle plate 26, and the perforated baffle plate 27 are degreased and washed in the state of a part, and molybdenum disulfide or graphite is applied to the surface of the part. The coated product is dried and baked to perform a strong surface treatment.
Surface treatment with molybdenum disulfide or graphite has heat resistance to the exhaust temperature, and specifically, at about 700 ° C., the surface treatment layer does not peel off.
In addition, this surface treatment layer has a high incompatibility with an oil component for the SUS material used for each shell.
[0021]
Next, the operation will be described.
[0022]
[Soot accumulation preventing action]
Dry soot adheres but hardly accumulates on parts with very smooth surfaces. However, when unburned fuel is mixed, unburned oil adheres to the component surface to form an oil film. This oil film burns on the surface of the component due to the high-temperature exhaust gas and forms a rough surface, and soot adheres and accumulates on this surface.
In the present embodiment, even if the oil adheres to the surface of the component and seizes due to the surface treatment having high affinity for the oil, the oil easily peels off and the seizure surface is not permanent. For this reason, a smooth surface on which soot does not easily adhere is maintained, and soot does not accumulate.
This prevents the holes of the perforated pipe 23, the perforated plugs 24 and 25, and the perforated baffle plate 27 from being blocked by soot, thereby maintaining a good noise reduction effect and moderate flow. It is adjusted to keep the flow toward the oxidation catalyst 31 uniform.
[0023]
[Cost control action]
In the present embodiment, since the surface treatment is performed with molybdenum disulfide or graphite, a surface treatment layer having a high affinity with an oil component is formed while suppressing the cost and withstanding the exhaust temperature.
In addition, since the perforated pipe 23, perforated plugs 24 and 25, perforated baffle plate 27, and baffle plate 26 are subjected to surface treatment in the state of components, they are easy to handle, and work costs and equipment costs are suppressed.
[0024]
Next, effects will be described.
[0025]
In the diesel particulate filter 41 of the embodiment, the following effects can be obtained.
[0026]
(1) Both ends of a cylindrical container body are reduced in diameter to form a front flange 21 and a rear flange 51 which are connected in the middle of an exhaust system of an engine, and the particulate matter in the exhaust is collected and reburned by the exhaust. A filter 41 is provided inside the front shell 11, and an oxidation catalyst 31 is provided in front of the particulate filter 41 inside the central shell 12 to make particulate matter in the exhaust gas easily reburnable. In the DPF device 1 provided with a perforated pipe 23, perforated plugs 24 and 25, a perforated baffle plate 27, and a baffle plate 26 provided in front of the oxidation catalyst 31 inside the front shell 11 to make the flow of the exhaust gas uniform. Surface treatment of a material that has heat resistance to temperature and has higher affinity for oil than each shell Since the pipe 23, the perforated plugs 24 and 25, the perforated baffle plate 27, and the baffle plate 26 are applied, the perforated pipe 23, the perforated plug 24, and the upstream of the oxidation catalyst 31 and the particulate filter 41 are made uniform. 25, a perforated baffle plate 27, and a baffle plate 26 can be provided, and the performance of the oxidation catalyst 31 and the particulate filter 41 can be exhibited so that the exhaust treatment can be performed efficiently and in a space-saving manner.
[0027]
(2) Both ends of the cylindrical container body are reduced in diameter to form a front flange 21 and a rear flange 51 which are connected in the middle of the exhaust system of the engine, and the particulate matter in the exhaust is collected and reburned by the exhaust. A filter 41 is provided inside the front shell 11, and an oxidation catalyst 31 is provided in front of the filter inside the front shell 11 to make the particulate matter in the exhaust gas easy to reburn, and exhaust gas taken into the inside of the front shell 11 from the front flange 21. In the DPF device 1 in which the perforated pipe 23, the perforated plugs 24 and 25, the perforated baffle plate 27, and the baffle plate 26 for providing noise reduction are provided in front of the oxidation catalyst 31 inside the front shell 11, heat resistance to exhaust gas temperature is reduced. Surface treatment of a material having a higher incompatibility with respect to the oil content than each shell. 24, 25, the perforated baffle plate 27, and the baffle plate 26, a silencing structure is provided upstream of the oxidation catalyst 31 and the particulate filter 41, and the performance is exhibited together with the oxidation catalyst 31 and the particulate filter 41. Exhaust treatment can be efficiently performed in a small space.
[0028]
(3) Since the perforated pipe 23, the perforated plugs 24 and 25, and the perforated baffle plate 27 have many small holes, and the surface treatment is to apply molybdenum disulfide or graphite, the cost is reduced. It is possible to suppress soot deposition so as not to block a large number of small holes.
[0029]
As described above, the diesel particulate filter device of the present invention has been described based on the embodiments. However, the specific configuration is not limited to these embodiments, and the invention according to each claim in the claims is described. Changes and additions to the design are permitted as long as they do not deviate from the gist.
[0030]
For example, although molybdenum disulfide or graphite is used as a surface treatment in the embodiment, a surface treatment of another material may be used, but a material having heat resistance and high incompatibility with an oil component is desirable.
Further, in the embodiment, the perforated pipe 23, the perforated plugs 24 and 25, the perforated baffle plate 27, and the baffle plate 26 are used as the structure. However, other structures may be used, and a structure which can easily perform the surface treatment is preferable.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a diesel particulate filter device according to an embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 DPF apparatus 11 Front shell 12 Central shell 13 Rear shell 14 Flange part 15 (connecting a front shell and a center shell) Flange part (connecting a center shell and a rear shell) 2 Diffusion chamber 21 Front flange 22 Curved end plate 23 Hole Perforated pipe 24 Perforated plug 25 Perforated plug 26 Baffle plate 27 Perforated baffle plate 3 Catalyst chamber 31 Oxidation catalyst 32 Catalyst holding mat 4 Filter chamber 41 Particulate filter 42 Filter holding mat 5 Wake connection chamber 51 Rear flange 6 Control sensor A Surface treatment range

Claims (3)

Both ends of the cylindrical container body are reduced in diameter and provided as connection ports for connection in the middle of the exhaust system of the engine, and a filter for collecting particulate matter in the exhaust gas and reburning the exhaust gas is provided inside the container body. An oxidation catalyst for providing a state in which particulate matter in the inside is easily reburned is provided in front of the filter inside the container body, and a structure for equalizing the flow of exhaust gas taken into the inside of the container body from the connection port is provided in the container. In a diesel particulate filter device provided in front of the oxidation catalyst inside the main body,
A diesel particulate filter device, wherein a surface treatment of a material having heat resistance to exhaust temperature and having a higher affinity for oil than the container body is applied to a structural portion inside the device main body. Both ends of the cylindrical container body are reduced in diameter and provided as connection ports for connection in the middle of the exhaust system of the engine, and a filter for collecting particulate matter in the exhaust gas and reburning the exhaust gas is provided inside the container body. An oxidation catalyst that makes the particulate matter in the state easy to reburn is provided in front of the filter inside the container body, and a structure that silences exhaust gas taken into the container body from the connection port is provided inside the container body. In the diesel particulate filter device provided in front of the oxidation catalyst,
A diesel particulate filter device, wherein a surface treatment of a material having heat resistance to exhaust temperature and having a higher affinity for oil than the container body is applied to a structural portion inside the device main body. The diesel particulate filter device according to claim 1 or 2,
A diesel particulate filter device, wherein the structure has many small holes, and the surface treatment is to apply molybdenum disulfide or graphite.

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