Honeycomb structure

Abstract

Provided is a honeycomb structure including a honeycomb substrate having partition walls defining cells extending from an inflow end face to an outflow end face, and plugging portions. The cells include at least one cell group consisting of a both-end plugged cell, an inlet cell adjacent to the both-end plugged cell, and an outlet cell adjacent to the both-end plugged cell. The partition walls defining the both-end plugged cell have a first common partition wall defining both of the inlet cell and the both-end plugged cell, and a second common partition wall defining both of the outlet cell and the both-end plugged cell. A first flow-through hole is formed in an end portion of the first common partition wall on the outflow end face side, and a second flow-through hole is formed in an end portion of the second common partition wall on the inflow end face side.

Description

[0001]The present application is an application based on JP-2014-033448 filed on Feb. 24, 2014 with the Japanese Patent Office, the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a honeycomb structure, and more particularly, relates to a honeycomb structure which is excellent in trapping efficiency and inhibits an increase of pressure loss when ash is accumulated.[0004]2. Background Art[0005]Heretofore, for the purpose of removing particulates (hereinafter also referred to as PM (Particulate Matter)) included in exhaust gas discharged from various engines and the like, exhaust gas purifying devices including honeycomb structure filter (honeycomb structure) have been used. There is known a honeycomb structure including a honeycomb structured honeycomb substrate and plugging portions disposed at open ends of inlet cells which are predetermined cells of this honeycomb substra...

AI Technical Summary

Benefits of technology

[0014]In consequence, there has earnestly been desired development of a honeycomb structure which has a favorable trapping efficiency and inhibits increase of pressure loss when ash is accumulated.

[0015]The present invention has been developed in view of such problems of conventional technologies, and an object thereof is to provide a honeycomb structure which has a favorable trapping efficiency and inhibits increase of pressure loss when ash is accumulated.

[0025]A honeycomb structure of the present invention has a trapping efficiency of the same degree as a trapping efficiency of a conventional honeycomb structure. That is, the honeycomb structure of the present invention is excellent in trapping efficiency. Furthermore, the honeycomb structure of the present invention has cell groups including three specific cells, and first flow-through holes and second flow-through holes are formed in predetermined partition walls, respectively. That is, in the honeycomb structure of the present invention, spaces where ash is deposited are present at two positions; at an end portion on the outflow end face side and at an end portion on the inflow end face side (see symbols X and Y of FIG. 2). Furthermore, in the honeycomb structure of the present invention, the ash which is accumulated in the honeycomb structure suitably joins a flow of an exhaust gas to be discharged outside along a route of an inlet cell, a both-end plugged cell and an outlet cell. Therefore, the honeycomb structure of the present invention inhibits an increase of a pressure loss when the ash is accumulated. As a result, maintenance operations when the ash is accumulated are performed less times, i.e., the maintenance operation may scarcely be needed to be performed. That is, the honeycomb structure is so-called free of maintenance in regard to deposition of ash.

Problems solved by technology

However, in honeycomb structures described in Patent Documents 1 and 2, one open end or the other open end of each cell is plugged, and hence pressure loss noticeably increases.

Furthermore, when ash which is a noncombustible substance included in PM is accumulated, such accumulated ash is hard to be discharged from the honeycomb structure.

Therefore, the pressure loss when ash is accumulated also noticeably increases.

However trapping efficiency of PM is deteriorated.

In a honeycomb structure described in Patent Document 4, similarly to Patent Document 3, there are cells in which no plugging portion is disposed, and hence the pressure loss increase is low, however as compared with the honeycomb structures described in Patent Documents 1 and 2, the trapping efficiency of PM is deteriorated.

Ash deposited in this portion is hard to be discharged.

In consequence, when the deposited ash is not discharged, the pressure loss disadvantageously increases.

On the other hand, a great deal of labor is required to discharge ash.

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