US-12623367-B2 - Method and device for producing honeycomb structure

US12623367B2US 12623367 B2US12623367 B2US 12623367B2US-12623367-B2

Abstract

A method for producing a honeycomb structure includes: a step of adjusting a penetration depth of a processing tool from an outer peripheral surface of a honeycomb structure base body having the honeycomb structure portion to a radially inward direction; and a step of forming at least one slit in the honeycomb structure base body according to the adjusted penetration depth, and wherein the penetration depth is adjusted by measuring a wall thickness of the outer peripheral wall of the honeycomb structure base body and then adding a predetermined value to the wall thickness.

Inventors

Ryuki Suzuki

Assignees

NGK INSULATORS, LTD.

Dates

Publication Date: 20260512
Application Date: 20230307
Priority Date: 20220317

Claims (10)

1 . A method for producing a honeycomb structure, the honeycomb structure comprising a honeycomb structure portion having: an outer peripheral wall; and a partition wall arranged on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells each extending from one end face to other end face to form a flow path, the honeycomb structure further comprising a plurality of slits each extending radially inward from an outer peripheral surface of the honeycomb structure and extending in an extending direction of the cells, wherein the method comprises: a step of adjusting a penetration depth of a processing tool from an outer peripheral surface of a honeycomb structure base body having the honeycomb structure portion to a radially inward direction; and a step of forming at least one slit in the honeycomb structure base body according to the adjusted penetration depth, and wherein the penetration depth is adjusted by measuring a wall thickness of the outer peripheral wall of the honeycomb structure base body and then adding a predetermined value to the wall thickness; and wherein the predetermined value is t×0.1 or more and p×0.35 or less, in which t is a thickness of the processing tool (mm), and p is a pitch between the cells (mm).
2 . The method for producing a honeycomb structure according to claim 1 , wherein adjusting the penetration depth comprises adjusting the penetration depth by measuring the wall thickness of the outer peripheral wall on both the one end face and the other end face, defining the wall thickness of the outer peripheral wall on the one end face as a first wall thickness, defining the wall thickness of the outer peripheral wall on the other end face as a second wall thickness, and adding a predetermined value to one of the first and second wall thicknesses when one of the first and second wall thicknesses is thicker than the other.
3 . The method for producing a honeycomb structure according to claim 1 , wherein the honeycomb structure base body further comprises a pair of electrode layers each arranged on the outer surface of the outer peripheral wall so as to extend in a form of a band in an extending direction of the cells across a central axis of the honeycomb structure portion, and wherein adjusting the penetration depth when forming the slits at positions where the electrode layers are provided comprises adjusting the penetration depth by measuring the wall thickness of the outer peripheral wall of the honeycomb structure base body and a thickness of each of the electrode layers, and then adding a predetermined value to the total thickness value of the thickness of the honeycomb structure base body and the thicknesses of the electrode layers.
4 . The method for producing a honeycomb structure according to claim 3 , wherein adjusting the penetration depth when forming the slits at the positions where the electrode layers are provided comprises adjusting the penetration depth by measuring the wall thickness of the outer peripheral wall and the thicknesses of the electrode layers on both the one end face and the other end face, defining the total value of the wall thickness of the outer peripheral wall and the thickness of the electrode layer on the one end face as a first total value, defining the total value of the wall thickness of the outer peripheral wall and the thickness of the electrode layer on the other end face as a second total value, and adding a predetermined value to one of the first and second total values when one of the first and second total values is larger than the other.
5 . The method for producing a honeycomb structure according to claim 1 , further comprising a step of specifying an outer peripheral surface position of the honeycomb structure base body at a plurality of positions aligned in the extending direction of the cells, wherein, when forming the slits, the honeycomb structure base body and the processing tool are relatively displaced based on the outer peripheral surface position specified at the plurality of positions.
6 . A device for producing a honeycomb structure, the honeycomb structure comprising a honeycomb structure portion having: an outer peripheral wall; and a partition wall arranged on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells each extending from one end face to other end face to form a flow path, the honeycomb structure further comprising a plurality of slits extending radially inward from an outer peripheral surface of the honeycomb structure and extending in an extending direction of the cells, wherein the device comprises: a holding portion for holding a honeycomb structure base body having the honeycomb structure portion; a processing tool for forming the plurality of slits in the honeycomb structure base body held by the holding portion; at least one measurement unit for measuring a wall thickness of the outer peripheral wall of the honeycomb structure base body; and a control unit for performing control such that a predetermined value is added to the wall thickness measured by the measurement unit to adjust a penetration depth of the processing tool from the outer peripheral surface of the honeycomb structure base body to a radially inward direction, and the processing tool is penetrated from the outer peripheral surface of the honeycomb structure base body to the radially inward direction at the adjusted depth; and wherein the predetermined value is t×0.1 or more and p×0.35 or less, in which t is a thickness of the processing tool (mm), and p is a pitch between the cells (mm).
7 . The device for producing a honeycomb structure according to claim 6 , wherein the measurement unit measures the wall thickness of the outer peripheral wall on both the one end face and the other end face, and wherein the control unit defines the wall thickness of the outer peripheral wall on the one end face as a first wall thickness, defines the wall thickness of the outer peripheral wall on the other end face as a second wall thickness, and adds a predetermined value to one of the first and second wall thicknesses to adjust the penetration depth when one of the first and second wall thicknesses is thicker than the other.
8 . The device for producing a honeycomb structure according to claim 6 , wherein the honeycomb structure base body further comprises a pair of electrode layers each arranged on the outer surface of the outer peripheral wall so as to extend in a form of a band in an extending direction of the cells across a central axis of the honeycomb structure portion, and wherein the measurement unit measures the wall thickness of the outer peripheral wall of the honeycomb structure base body and a thickness of each of the electrode layers at positions where the electrode layers are provided, and wherein the control unit adjusts the penetration depth by adding a predetermined value to the total value of the thickness of the honeycomb structure base body and the thicknesses of the electrode layers when forming the slits at the positions where the electrode layers are provided.
9 . The device for producing a honeycomb structure according to claim 8 , wherein the measurement unit measures the wall thickness of the outer peripheral wall and the thicknesses of the electrode layers on both the one end face and the other end face, and wherein the control units defines the total value of the wall thickness of the outer peripheral wall and the thickness of the electrode layer on the one end face as a first total value, defines the total value of the wall thickness of the outer peripheral wall and the thickness of the electrode layer on the other end face as a second total value, and adjusts the penetration depth by adding a predetermined value to one of the first and second total values when one of the first and second total values is larger than the other.
10 . The device for producing a honeycomb structure according to claim 6 , further comprising an outer peripheral surface position specifying unit for specifying an outer peripheral surface position of the honeycomb structure base body at a plurality of positions aligned in the extending direction of the cells, wherein the control unit controls relative displacement of the honeycomb structure base body and the processing tool based on the outer peripheral surface position specified at the plurality of positions.

Description

FIELD OF THE INVENTION The present invention relates to a method and device for producing a honeycomb structure. BACKGROUND OF THE INVENTION In general, electrically heating catalysts (EHCs) are known. The EHCs are for purifying an exhaust gas emitted when an engine (internal combustion engine) is in a cold state immediately after the engine is started, by arranging electrodes on a honeycomb structure made of conductive ceramics, and heating the honeycomb structure itself by energization to increase a temperature of a catalyst supported on the honeycomb structure to an activation temperature before starting the engine. As described in Patent Literature 1 below, a honeycomb structure includes: a pillar shaped honeycomb structure portion having an outer peripheral wall and a partition wall disposed on an inner side of the outer peripheral wall; and a pair of electrode portions for attaching electrodes. By applying a voltage to the honeycomb structure through the electrodes and the electrode portions, the honeycomb structure generates heat. For the purpose of suppressing bias in temperature distribution of the honeycomb structure when a voltage is applied or the like, the honeycomb structure portion is provided with a plurality of slits each extending radially inward from the outer peripheral wall of the honeycomb structure portion and extending in an extending direction of cells of the honeycomb structure portion. Each of the slits is formed using a processing tool such as Leuter. More particularly, the slits are formed by inserting a processing tool from the outside of the outer peripheral wall into the honeycomb structure portion by a predetermined set amount (fixed value). CITATION LIST Patent Literature [Patent Literature 1] Japanese Patent Application Publication No. 2015-174011 A SUMMARY OF THE INVENTION In the conventional method for producing the honeycomb structure, the slits are formed by inserting a processing tool into the honeycomb structure portion by a predetermined set amount from the outside of the outer peripheral wall. Therefore, if the wall thickness of the outer peripheral wall is thicker than expected, there is a risk that the processing tool cannot penetrate the outer peripheral wall and incomplete slits are formed. On the other hand, if the wall thickness of the outer peripheral wall is thinner than expected, there is a risk that the processing tool may enter the honeycomb structure portion more than necessary and damage the partition wall unnecessarily. The present invention has been made to solve the above problems. An object of the present invention is to provide a method and device for producing a honeycomb structure, which can more surely form the slits and reduce the risk of unnecessarily damaging the partition wall. Aspect 1. In an embodiment, the present invention relates to a method for producing a honeycomb structure, the honeycomb structure comprising a honeycomb structure portion having: an outer peripheral wall; and a partition wall arranged on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells each extending from one end face to other end face to form a flow path, the honeycomb structure further comprising a plurality of slits each extending radially inward from an outer peripheral surface of the honeycomb structure and extending in an extending direction of the cells, wherein the method comprises: a step of adjusting a penetration depth of a processing tool from an outer peripheral surface of a honeycomb structure base body having the honeycomb structure portion to a radially inward direction; and a step of forming at least one slit in the honeycomb structure base body according to the adjusted penetration depth, and wherein the penetration depth is adjusted by measuring a wall thickness of the outer peripheral wall of the honeycomb structure base body and then adding a predetermined value to the wall thickness. Aspect 2. The present invention may relate to the method for producing a honeycomb structure according to the aspect 1, wherein adjusting the penetration depth comprises adjusting the penetration depth by measuring the wall thickness of the outer peripheral wall on both the one end face and the other end face, defining the wall thickness of the outer peripheral wall on the one end face as a first wall thickness, defining the wall thickness of the outer peripheral wall on the other end face as a second wall thickness, and adding a predetermined value to one of the first and second wall thicknesses when one of the first and second wall thicknesses is thicker than the other. Aspect 3. The present invention may relate to the method for producing a honeycomb structure according to the aspect 1 or 2, wherein the predetermined value is t×0.1 or more and p×0.35 or less, in which t is a thickness of the processing tool (mm), and p is a pitch between the cells (mm). Aspect 4. The present invention may relate to the method for produ