Honeycomb structure

Abstract

A honeycomb structure includes: a honeycomb segment joined body having a plurality of honeycomb segments unitarily joined at bonding faces thereof by means of a bonding material layer, and an outer peripheral coat layer covering a surface of an outer peripheral portion of the honeycomb segment joined body; in which a plurality of cells functioning as fluid passages are disposed to be in parallel with one another in a direction of a central axis. A bonding material layer between honeycomb segments constituting a central portion with respect to a diametral direction of the honeycomb segment joined body is made thicker than a bonding material layer between honeycomb segments constituting the outer peripheral portion of the honeycomb segment joined body. The honeycomb structure is useful as a trapping filter for exhaust gas, particularly, as a diesel particulate filter (DPF) for trapping particulate matter or the like in exhaust gas from a diesel engine and can effectively inhibit occurrence of a defect such as a crack due to thermal stress upon use or upon regeneration.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example of a cross-sectional view in a diametral direction in a honeycomb structure (Example 1) of the present invention.

FIG. 2 is an example of a cross-sectional view in a diametral direction in a honeycomb structure (Example 2) of the present invention.

FIG. 3 is an example of a cross-sectional view in a diametral direction in a honeycomb structure (Comparative Example 1).

FIG. 4 is a cross-sectional view in a diametral direction showing another embodiment of a honeycomb structure of the present invention.

FIG. 5 is a cross-sectional view in a diametral direction showing still another embodiment of a honeycomb structure of the present invention.

FIG. 6 is an example of a cross-sectional view in a diametral direction in a conventional honeycomb structure (Comparative Example 2).

FIG. 7 is a schematic view showing a measurement position of a adhesive thickness in portions where four honeycomb segments not disposed in the outermost periphery of a honeycomb structure are facing one another.

FIG. 8 is a perspective view schematically showing an example of an embodiment (having a circular whole cross section taken along a plane perpendicular to the central axis) of a honeycomb structure.

FIG. 9 is a perspective view schematically showing an example of a honeycomb segment used in a honeycomb structure.

FIG. 10 is a cross-sectional view taken along A-A of FIG. 9.

Claims

1. A honeycomb structure comprising: a honeycomb segment joined body having a plurality of honeycomb segments unitarily joined at bonding faces thereof by means of a bonding material layer, andan outer peripheral coat layer covering a surface of an outer peripheral portion of the honeycomb segment joined body;in which a plurality of cells functioning as fluid passages are disposed to be in parallel with one another in a direction of a central axis;wherein a bonding material layer between honeycomb segments constituting a central portion with respect to a diametral direction of the honeycomb segment joined body is made thicker than a bonding material layer between honeycomb segments constituting the outer peripheral portion of the honeycomb segment joined body.

2. A honeycomb structure according to claim 1, wherein a bonding material layer between the honeycomb segments constituting the central portion with respect to a diametral direction of the honeycomb segment joined body is 2 to 5 times thicker than a bonding material layer between the honeycomb segments constituting the outer peripheral portion of the honeycomb segment joined body.

3. A honeycomb structure according to claim 1, wherein an R portion is provided at a corner of each of the honeycomb segments constituting the honeycomb segment joined body.

4. A honeycomb structure according to claim 1, wherein a size of the honeycomb segments constituting the central portion with respect to a diametral direction of the honeycomb segment joined body is smaller than that of the honeycomb segments constituting the outer peripheral portion of the honeycomb segment joined body.