Method of producing honeycomb structural body

Patent metadata

Field	Value
Publication number	US-9950442-B2
Application number	US-201414542116-A
Country	US
Kind code	B2
Filing date	Nov 14, 2014
Priority date	Nov 15, 2013
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method feeds raw material into a metal die and extrudes the raw material to produce a honeycomb molded body. The method fires the honeycomb molded body to make a honeycomb structural body. The metal die has a first metal die and a second metal die arranged at an upstream side of an extrusion direction of the raw material and a second metal die arranged at a downstream side of the extrusion direction of the raw material. The first metal die has a projection section and the second metal die has a penetration hole. The projection section is fitted to the penetration hole to assemble the first metal die and the second metal die. Communication holes formed in the second metal die communicate with raw material second feeding holes formed in the first metal die.

First claim

What is claimed is:

1. A method of producing a honeycomb structural body using a metal die, comprising steps of:
shaping a honeycomb molded body by feeding raw material from a feeding surface side to an inside of the metal die, and extruding the fed raw material from an extrusion surface of the metal die outside of the metal die; and
firing the honeycomb molded body to produce a honeycomb structural body, wherein
the method uses the metal die comprising a first metal die arranged at an upstream side of an extrusion direction of the raw material and a second metal die arranged at a downstream side of the extrusion direction, wherein
the first metal die comprises:
a projection section projected toward the downstream side of the first metal die in the extrusion direction;
a plurality of raw material first feeding holes;
first slits; and
a plurality of raw material second feeding holes, wherein the plurality of raw material first feeding holes are formed in the projection section extending from the feeding surface toward the extrusion direction,
the first slits are formed in a honeycomb structural shape on the extrusion surface to communicate with the plurality of raw material first feeding holes, and
the plurality of raw material second feeding holes are formed around the projection section of the first metal die, and the feeding surface communicates with an abutting surface of the second metal die through the plurality of raw material second feeding holes,

the second metal die comprises:
a penetration hole fitted with the projection section of the first metal die in the metal die;
a plurality of communication holes which are formed around the penetration hole and extended toward the extrusion direction from the abutting surface side; and
second slits arranged in a honeycomb structural shape on the extrusion surface to communicate with the plurality of communication holes, and
the plurality of communication holes in the second metal die communicating with the raw material second feeding holes in the first metal die.

2. The method of producing a honeycomb structural body according to claim 1 , wherein the shaping step shapes the honeycomb molded body which comprises:
an outer skin layer having a cylindrical shape;
cell walls arranged in a lattice like shape in the outer skin layer; and
a plurality of cells surrounded by the cell walls,
wherein a central section and an outer peripheral section are formed in a cross section which is perpendicular to an axial direction of the honeycomb molded body, the axial direction is equal to the extrusion direction, and
the central section contains a central axis of the honeycomb molded body and the outer peripheral section surrounds the central section.

3. The method of producing a honeycomb structural body according to claim 2 , wherein the shaping step forms the honeycomb molded body which further comprises a boundary partition wall between the central section and the outer peripheral section so that the boundary partition wall separates the central section from the outer peripheral section.

4. The method of producing a honeycomb structural body according to claim 1 , wherein the method uses the metal die in which the first metal die further comprises a positioning hole and the second metal die further comprises a positioning hole, and the first metal die and the second metal die are fixed together by using a positioning member which is inserted in the positioning holes.

5. The method of producing a honeycomb structural body according to claim 1 , wherein the method uses the metal die in which the first metal die is connected to the second metal die.

6. The method of producing a honeycomb structural body according to claim 1 , wherein the method produces the honeycomb molded body having a structure in which the raw material second feeding holes in the first metal die has a diameter which is larger than a diameter of the plurality of communication holes in the second metal die.

7. The method of producing a honeycomb structural body according to claim 1 , wherein the method uses the metal die in which a corner section of the projection section in the first metal die has a curved surface or a slope, and a contact section in the second metal die has a curved surface or a slope so that the first metal die is fitted to the second metal die through the corner section and the contact section.

8. The method of producing a honeycomb structural body according to claim 1 , wherein the method uses the metal die in which a deformation of the first metal die and the second metal die follows a deformation in the metal die generated when the raw material passes through the metal die.

9. The method of producing a honeycomb structural body according to claim 8 , wherein the method uses the metal die which satisfies a relationship of E 1 /E 2 <14.4 and a relationship of T 1 /(T 1 +T 2 )≤0.67, where E 1 indicates a Young's modulus of the first metal die, E 2 indicates a Young's modulus of the second metal die, T 1 is a minimum thickness of the first metal die, and T 2 indicates a minimum thickness of the second metal die.

Assignees

• Denso Corp

Inventors

• Hayashi Naohiro

Classifications

• F01N2330/48

  characterised by the number of flow passages, e.g. cell density · CPC title

• C04B35/565

  based on silicon carbide · CPC title

• B29C48/11

  comprising two or more partially or fully enclosed cavities, e.g. honeycomb-shaped · CPC title

• C04B35/195

  Alkaline earth aluminosilicates, e.g. cordierite {or anorthite} · CPC title

• B29C48/304

  specially adapted for bringing together components, e.g. melts within the die · CPC title