Electrically heatable honeycomb body with resistance increased by slits

Abstract

An electrically heatable honeycomb body, in particular a carrier body for a catalytic converter, includes wound, stacked or otherwise layered sheet-metal layers along which a fluid can flow in a primary flow direction, with at least some of the layers being structured. At least one layer has openings for lengthening and/or narrowing an electrically conductive path therein. The structuring of the layers and the formation and disposition of the openings cause adjacent layers to touch substantially only at locations without the openings in the at least one layer. A sheet-metal layer has raised locations and a periodic and in particular approximately undulating or trapezoidal structure with rising and falling regions and a periodicity defining a period. A method for producing slits extending approximately parallel to the raised locations includes delivering the layer with the periodic structure to a shearing device having a periodic structure, having first and second shears facing one another and being offset from one another, and having a periodicity being equal to the periodicity of the period of the layer, and touching the layer with the shearing device only in at least one of the regions. The shears are moved toward one another until the layer is firmly clamped. The first shears are moved relative to the second shears and a slit is created in each of the rising and falling regions by shearing. The shears move away from one another and expel the slit layer.