JP2009082769A - Particulate filter and exhaust gas cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost particulate filter capable of securing structural strength with simple structure, and securing enough surface area, without causing deterioration of metallic fiber. <P>SOLUTION: The particulate filter for treating particulates contained in exhaust gas discharged from a diesel engine, has corrugated plate filters 9 and flat plate filters 10 of porous structure consisting of the metallic fiber, is constituted so that the flat plate filters 10 are inserted into slits 11 formed in the corrugated plate filters 9 along the flow direction of the exhaust gas to the filters 9, and the corrugated plate filters 9 and flat plate filters 10 are diffusion-joined. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a particulate filter and an exhaust purification device using the particulate filter.

  For example, Patent Document 1 discloses a particulate filter that collects particulates discharged from a diesel engine.

  As shown in FIG. 6 and FIG. 7, the particulate filter described in the cited document 1 is bent into a corrugated plate shape by bending a metal fiber nonwoven fabric or a ceramic fiber nonwoven fabric carrying a catalyst into a valley and a substantially cylindrical shape. The filter element 1 is disposed inside the outer cylinders 2 and 3 formed of two cylindrical bodies having a comb-teeth shape, and these are joined by brazing.

  Moreover, in this particulate filter, the support rod 4 is arrange | positioned inside the U-shaped bending part of a nonwoven fabric, and the durability of a bending part is improved. And in the particulate filter comprised in this way, it is set as what is called an alternate sealing structure by which the dead end part was formed alternately by the waste gas inlet side and the waste gas outlet side by making the filter element 1 into a corrugated plate shape. Yes.

Further, in Patent Document 1, as shown in FIG. 8, corrugated corrugated sheet 5 is sandwiched between non-woven fabric surfaces of filter element 1 facing U-bend, and their contact portions are brazed. A structured particulate filter is disclosed.
JP 2002-221020 A

  By the way, in the particulate filter, when the particulates are collected, the particulate filter is clogged and the pressure loss becomes high. Therefore, it is necessary to periodically burn and remove the particulates. The filter carries a catalyst for assisting combustion of particulates, and in order to efficiently remove particulates, it is necessary to increase the filter surface area and increase the contact efficiency between the exhaust gas and the catalyst.

  However, there is a limit to the surface area that can be secured by bending a metal fiber nonwoven fabric as a valley. In FIG. 8, corrugated corrugated corrugated metal plates 5 are brazed between the nonwoven fabric surfaces of the filter element 1 to secure the filter surface area. However, when metal fibers are joined together by brazing, the metal fibers are deteriorated. There is a fear.

  In addition, in the particulate filter described in Patent Document 1, the support rod 4 is used because the structural strength is insufficient only with the metal fiber, but the mounting work of the support rod 4 and the cost of itself are high. Become.

  Therefore, in order to solve the above-described problems, the present invention provides a low-cost particulate filter and an exhaust purification device that can secure a sufficient surface area without incurring metal fiber deterioration, a simple structure, and a sufficient surface area. The purpose is to provide.

  The present invention according to claim 1 is a particulate filter for processing particulates contained in exhaust gas discharged from a diesel engine, and includes a corrugated plate filter and a flat plate filter having a porous structure made of metal fibers. The flat plate filter is inserted into a slit formed in the corrugated plate filter along the flow direction of the exhaust gas with respect to the corrugated plate filter, and the corrugated plate filter and the flat plate filter are diffusion bonded. Yes.

  A second aspect of the present invention is the particulate filter according to the first aspect, wherein a plurality of the slits are formed in the corrugated plate filter in the width direction, and the flat plate filter is inserted into each slit to diffuse. It is characterized by being joined.

  Invention of Claim 3 is the particulate filter of Claim 1 or Claim 2, Comprising: The flat plate filter was each provided in the height direction upper-lower-end position of the said corrugated filter, and was diffusion-joined. It is characterized by.

  The invention according to claim 4 is characterized in that at least the particulate filter according to any one of claims 1 to 3 is arranged in an outer cylinder to form an exhaust purification device.

  According to the particulate filter according to claim 1, a slit is formed in the corrugated filter made of a metal fiber and has a porous structure, and a flat plate filter having a porous structure made of a metal fiber is inserted into the slit. Since these filters are diffusion-bonded, the surface area is greatly increased by the use of a flat plate filter, and metal fibers are not deteriorated by brazing because they are bonded by diffusion bonding. Therefore, in the particulate filter of the present invention, the particulate processing capability is increased by increasing the surface area and eliminating the brazing, and the structural strength can be increased by the flat plate filter without using a strength reinforcing member such as a support member.

  According to the invention described in claim 2, since the plurality of slits are formed in the corrugated filter, and the flat plate filter is inserted into each slit and diffusion-bonded, the increase in the number of flat plate filters further increases the number of flat plate filters. The surface area can be increased and the structural strength is increased.

  According to the third aspect of the present invention, since the flat plate filters are respectively provided at the upper and lower end positions in the height direction of the corrugated filter and diffusion bonded, the strength of the upper and lower end portions of the corrugated filter can be increased.

  According to the invention described in claim 4, since the particulate filter according to any one of claims 1 to 3 is disposed in the outer cylinder, the particulate filter is less likely to be clogged and has a low pressure loss. It is possible to provide an exhaust purification device with high processing performance.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  1 is a cross-sectional view of the exhaust emission control device of the present embodiment, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is a manufacturing process diagram of the particulate filter of the present embodiment, and FIG. It is a figure which shows the exhaust gas flow with respect to a curate filter.

  The exhaust purification device 3 of this embodiment is installed in, for example, an exhaust system. As shown in FIG. 1, the particulate filter 6 that collects particulates discharged from the diesel engine 1 and the particulates are collected. The filter 6 is housed and fixed inside, and is composed of an outer cylinder 7 that guides exhaust gas by connecting exhaust pipes at the front and rear. The particulate filter 6 is accommodated via a mat 8 inside an outer cylinder 7 that also functions as a diffuser that allows the introduced exhaust gas to pass through the particulate filter 6 evenly.

  The particulate filter 6 has a corrugated filter 9 and a flat filter 10 having a porous structure made of metal fibers, and is formed in the corrugated filter 9 along the flow direction of the exhaust gas with respect to the corrugated filter 9. The flat plate filter 10 is inserted into the slit 11 and the corrugated plate filter 9 and the flat plate filter 10 are diffusion bonded. The corrugated plate filter 9 and the flat plate filter 10 carry a catalyst for assisting the removal of particulates contained in the exhaust gas.

  The corrugated filter 9 and the flat filter 10 are formed by, for example, collecting metal fibers made of a very thin stainless material having a wire diameter of 34 μm and packing them in a mold, and then sintering the metal fibers. The corrugated filter 9 is formed by bending a long belt-like plate into a bellows shape. The corrugated filter 9 is formed into a bellows shape by having a plurality of U-shaped portions formed by connecting rectangular filter plane portions 9a with connecting portions 9b. Further, the corrugated filter 9 has a plurality of slits 11 formed in the width direction of the corrugated sheet. The slits 11 are connected at one end of the corrugated plate so as not to fall apart.

  On the other hand, the flat filter 10 has a flat plate shape that is large enough to completely cover the end surface in the width direction of the corrugated filter 9. The flat filter 10 is inserted into each of the slits 7 formed in the wave direction of the corrugated filter 9 and is provided at both end positions in the width direction of the height corrugated plate. In other words, the flat plate filter 10 is provided at the upper and lower positions so as to sandwich the corrugated filter 9, and the flat plate filter 10 is inserted into each slit 7 formed in the corrugated filter 9 and sandwiched.

  The corrugated filter 9 and the flat filter 10 are joined and integrated by diffusion joining. Diffusion bonding is a bonding method in which heating and pressurization are performed in an inert atmosphere (for example, in vacuum, an inert gas such as argon), and heating is performed below the melting point of the material. Diffusion bonding will be explained a little more. The base material is brought into close contact, and the pressure is applied to the extent that plastic deformation does not occur as much as possible under a temperature condition below the melting point of the base material. The method is diffusion bonding. On the other hand, welding and brazing are joining by using a brazing material as an adhesive and melting the base material.

  Thus, unlike brazing in which the base material is melted and joined, the corrugated plate filter 9 and the flat plate filter 10 are joined and integrated by diffusion joining in which joining is performed under heating below the melting point of the base material. Moreover, deterioration of the metal fiber can be prevented without melting the metal fiber itself.

  In addition, when the corrugated filter 9 and the flat filter 10 are joined by brazing, the temperature approaches the base material melting temperature of the filter, and the metal fibers that are the filter may be melted. Moreover, since it is a fiber, the melt | dissolved wax will block | close the space between fibers and will raise ventilation resistance. On the other hand, in diffusion bonding, since only the parts in contact with the fiber material are bonded, there is an advantage that the space can be bonded and the air flow resistance can be increased without increasing.

  In the particulate filter 6 configured in this way, as shown by the arrow in FIG. 4, the exhaust gas flows into the gap portion 12 between the filter flat portions 9a that opens to the exhaust gas inlet side, and opens to the exhaust gas outlet side. Flows through the filter plane 9a to the space 13 to be formed. At this time, the particulates contained in the exhaust gas come into contact with the catalyst supported on the filter by each filter plane portion 9a and are burned and removed.

  Further, the particulates are not only processed by the filter plane part 9 a of the corrugated filter 9 but are also processed by the flat filter 10. For this reason, the filter surface area for processing the particulates is greatly increased by the flat plate filter 10 in addition to the corrugated plate filter 9, thereby increasing the particulate processing capability.

  As described above, according to the present embodiment, the slit 11 is formed in the corrugated filter 9 having a porous structure made of metal fibers, and the flat plate filter 10 having the same porous structure made of metal fibers is inserted into the slit 11. Since the filters 9 and 10 are diffusion bonded, the surface area is greatly increased by using the flat filter 10, and the metal fibers are not clogged by the brazing material because the bonding is performed by diffusion bonding. Therefore, in the particulate filter 6 of the present invention, the particulate processing capacity is increased by increasing the surface area, preventing clogging of the metal fibers, and preventing the deterioration of the metal fibers, and the structural strength is obtained by the flat plate filter without using a strength reinforcing member such as a support member. Can be increased.

  In addition, according to the present embodiment, a plurality of slits 11 are formed in the corrugated filter 9, and the flat plate filters 10 are inserted into the slits 11 for diffusion bonding, so that the number of flat plate filters 10 increases. Further, the surface area can be further increased and the structural strength is increased.

  Moreover, according to this embodiment, since the flat plate filter 10 is provided in the width direction edge position of the corrugated filter 9, and it carries out the diffusion joining, the intensity | strength of the corrugated filter width direction edge part can also be raised.

  In addition, according to the present embodiment, the particulate filter 6 of the present invention is disposed in the outer cylinder 7 and the front and rear are connected to the exhaust pipe, so that it is difficult to clog, the pressure loss is low, and the particulate processing performance is high. The exhaust purification device can be easily applied to an exhaust system.

  The specific embodiment to which the present invention is applied has been described above, but the present invention is not limited to the above-described embodiment.

  For example, in the above-mentioned embodiment, as shown in FIG. 5 (a), the filter plane portions 9a of the corrugated filter 9 are all parallel, but as shown in FIG. The filter plane portion 9a may have an angle so that it is not parallel. In this way, since the filter plane portion 9a has an inclination angle with respect to the flow direction of the exhaust gas, an effect of further increasing the particulate processing efficiency can be obtained.

FIG. 1 is a cross-sectional view of the exhaust purification apparatus of this embodiment. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a manufacturing process diagram of the particulate filter of this embodiment. FIG. 4 is a view showing an exhaust gas flow with respect to the particulate filter of the present embodiment. FIG. 5A is a perspective view of the corrugated filter when the filter plane portions are all parallel, and FIG. 5B is a perspective view of the corrugated filter when the filter plane portions are angled. FIG. 6 is a perspective view of a conventional exhaust purification device. FIG. 7 is an exploded perspective view of the exhaust purification device of FIG. FIG. 8 is a view showing an example in which a corrugated plate is further joined to the particulate filter shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Exhaust gas purification device 6 ... Particulate filter 7 ... Outer cylinder 9 ... Corrugated plate filter 10 ... Flat plate filter 11 ... Slit

Claims (4)

In a particulate filter that processes particulates contained in exhaust gas discharged from a diesel engine,
A corrugated filter (9) and a flat filter (10) having a porous structure made of metal fibers,
The flat plate filter (10) is inserted into a slit (11) formed in the corrugated plate filter (9) along the flow direction of the exhaust gas with respect to the corrugated plate filter (9). And a flat plate filter (10) are diffusion bonded. The particulate filter according to claim 1,
A plurality of slits (11) are formed in the corrugated filter (9) in the width direction, and the flat plate filter (10) is inserted into each of the slits (11) and diffusion bonded. filter. The particulate filter according to claim 1 or 2, wherein
A particulate filter characterized in that a flat plate filter (10) is provided at each end in the width direction of the corrugated filter (9) and diffusion bonded. An exhaust emission control device characterized in that at least the particulate filter (6) according to any one of claims 1 to 3 is disposed in an outer cylinder (7) to form an exhaust emission control device.

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