Method for the manufacture of an exhaust gas converter, tool for a ring press for the manufacture of an exhaust gas converter, ring press comprising a tool, and exhaust gas converter manufactured with a ring press

Abstract

A method for manufacturing an exhaust gas converter and a tool for the method are provided. The method includes providing a cylindrical metal pipe and a cylindrical substrate surrounded in a circumferential direction by a mat mount. The substrate is deposited with the mat mount surrounding it inside the metal pipe. A compression force is exerted on the metal pipe, directed in a radial direction, for reducing the cross-section of the metal pipe to a desired size. Regions to which a compression force is applied alternate along the circumferential direction of the metal pipe with regions to which no compression force is applied. A number of regions where no compression force is applied to the metal pipe exceeds the number of tools used for applying the compression force. The tool ( 4 ), for a ring press, includes a tool body including a mounting section and a work section with recesses ( 45 ).

What is claimed is: 
     
         1 . A method for the manufacture of an exhaust gas converter, the method comprising the steps of:
 providing a cylindrical metal pipe;   providing a cylindrical substrate surrounded in a substrate circumferential direction by a mat mount, the cross-section of the substrate including the mat mount being smaller or equal to a cross-section of the metal pipe;   disposing the substrate with the mat mount surrounding the substrate inside the metal pipe; and   exerting a compression force on the metal pipe with tools, the compression force being directed in a radial direction of the metal pipe for reducing the cross-section of the metal pipe to a desired size, wherein regions to which a compression force is applied alternate along a metal pipe circumferential direction with regions to which no compression force is applied; and wherein a number of the regions to which no compression force is applied exceeds a number of the tools used for applying the compression force.   
     
     
         2 . A method in accordance with  claim 1 , further comprising the steps of heating of the metal pipe to a temperature of between 100° C. and 300° C. prior to exposing the metal pipe to a compression force. 
     
     
         3 . A tool for a ring press, the tool comprising a tool body with an extension in an axial direction of the ring press, an extension in a radial direction of the ring press, and an extension in a circumferential direction of the ring press, the tool body comprising:
 a mounting section configured for fixing the tool on the ring press; and   a work section wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press, the work section comprising a tangential surface having a right cylinder lateral area shape and being configured for exerting compression on an encasement of an exhaust gas converter and a plurality of recesses, the recesses having, along a radial direction, a maximum depth of at least 1/20 mm wherein the recesses are oriented in an axial direction of the ring press and are spaced apart from one another in a circumferential direction of the ring press wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press.   
     
     
         4 . A tool in accordance with  claim 3 , wherein the recesses have, along the radial direction, a maximum depth of not more than 20 mm. 
     
     
         5 . A tool in accordance with  claim 3 , wherein:
 at least one recess extends in the axial direction across a whole of the extension of the work section; or   all recesses extend in the axial direction across the whole of the extension of the work section.   
     
     
         6 . A tool in accordance with  claim 3 , wherein the recesses are equidistantly spaced in pairs. 
     
     
         7 . A tool in accordance with one of  claim 3 , wherein
 the recesses each have an extension in a longitudinal direction and an extension in a transverse direction, the extension in the longitudinal direction and the extension in the transverse direction being orthogonal with respect to each other and orthogonal with respect to the extension in the radial direction; and   the extension in the longitudinal direction is at least 20 times as long as the extension in the transverse direction, or the extension in the longitudinal direction is at least 80 times as long as the extension in the transverse direction.   
     
     
         8 . A tool in accordance with  claim 7 , wherein the extension of the recesses in the transverse direction does not exceed 10 mm. 
     
     
         9 . A tool in accordance with  claim 3 , wherein the recesses each have a cross-section, a form of which corresponds to a segment of a circle or to a trapezoid. 
     
     
         10 . A tool in accordance with  claim 3 , wherein
 the work section comprises, in a circumferential direction of the tool, at least one first section and one third section having recesses formed therein, and one second section located between the first and the third sections having no recesses formed therein; and   the first, second, and third sections each extend across at least 5% and not more than 50% of the work section in the circumferential direction of the tool.   
     
     
         11 . A tool in accordance with  claim 3 , wherein the recesses occupy at least 3% of a surface of the work section. 
     
     
         12 . A ring press comprising:
 a plurality of tools, each tool comprising a tool body with an extension in an axial direction of the ring press, an extension in a radial direction of the ring press, and an extension in a circumferential direction of the ring press, the tool body comprising:   a mounting section configured for fixing the tool on the ring press; and   a work section wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press, the work section comprising a tangential surface having a right cylinder lateral area shape and being configured for exerting compression on an encasement of an exhaust gas converter and a plurality of recesses, the recesses having, along a radial direction, a maximum depth of at least 1/20 mm wherein the recesses are oriented in an axial direction of the ring press and are spaced apart from one another in a circumferential direction of the ring press wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press, wherein the plurality of tools are fixed in the ring press by the mounting sections, wherein the ring press is configured to move each tool of the plurality of tools in either of two opposite directions of movement, the opposite directions of movement following straight lines and the directions of movement of all tools of the plurality of tools intersecting in one point, whereby the ring press can take part in a method of manufacturing an exhaust gas converter with a provided cylindrical metal pipe and cylindrical substrate surrounded in a substrate circumferential direction by a mat mount, the cross-section of the substrate including the mat mount being smaller or equal to a cross-section of the metal pipe with the substrate deposited with the mat mount surrounding the substrate inside the metal pipe by exerting a compression force on the metal pipe with tools, the compression force being directed in a radial direction of the metal pipe for reducing the cross-section of the metal pipe to a desired size, wherein regions to which a compression force is applied alternate along a metal pipe circumferential direction with regions to which no compression force is applied; and wherein a number of the regions to which no compression force is applied exceeds a number of the tools used for applying the compression force.   
     
     
         13 . The ring press in accordance with  claim 12 , wherein
 the tools are fixed in the ring press along a circle; and   an air gap is provided between two tools, disposed adjacent thereto, along the circle.   
     
     
         14 . An exhaust gas converter comprising:
 a cylindrical encasement made from sheet material;   a cylindrical substrate disposed inside the encasement; and   a mat mount located between the substrate and the encasement, wherein the encasement comprises at least three protrusions, wherein the protrusions are oriented in an axial direction of the encasement and are spaced apart from one another in a circumferential direction of the encasement, and wherein the protrusions have, in a radial direction of the encasement, a maximum height of at least 1/20 mm.   
     
     
         15 . An exhaust gas converter in accordance with  claim 14 , wherein the protrusions in the radial direction of the encasement have a maximum height of not more than 20 mm. 
     
     
         16 . An exhaust gas converter in accordance with  claim 14 , wherein:
 the at least one protrusion extends in the axial direction of the encasement across the whole of the extension of the encasement; or   all protrusions extend in the axial direction of the encasement across the whole of the extension of the encasement.   
     
     
         17 . An exhaust gas converter in accordance with  claim 14 , wherein the protrusions are equidistantly spaced in pairs. 
     
     
         18 . An exhaust gas converter in accordance with  claim 14 , wherein:
 the protrusions each have an extension in the longitudinal direction and an extension in the transverse direction, the extension in the longitudinal direction and the extension in the transverse direction of the respective protrusion being orthogonal with respect to each other and orthogonal with respect to the extension in the direction of a height of the respective protrusion; and   the extension in the longitudinal direction is at least 20 times as long as the extension in the transverse direction.   
     
     
         19 . An exhaust gas converter in accordance with  claim 18 , wherein the extension of the protrusions in the transverse direction is not more than 10 mm. 
     
     
         20 . An exhaust gas converter in accordance with  claim 14 , wherein the protrusions each have a cross-section, the shape of which corresponds to a segment of a circle, a segment of an arc of a circle, or a segment of a trapezoid. 
     
     
         21 . An exhaust gas converter in accordance with  claim 14 , wherein the protrusions occupy at least 5% of the surface of the encasement and not more than 50% of the surface of the encasement. 
     
     
         22 . An exhaust gas converter in accordance with  claim 14 , formed with a ring press comprising:
 a plurality of tools, each tool comprising a tool body with an extension in an axial direction of the ring press, an extension in a radial direction of the ring press, and an extension in a circumferential direction of the ring press, the tool body comprising:   a mounting section configured for fixing the tool on the ring press; and   a work section wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press, the work section comprising a tangential surface having a right cylinder lateral area shape and being configured for exerting compression on an encasement of an exhaust gas converter and a plurality of recesses, the recesses having, along a radial direction, a maximum depth of at least 1/20 mm wherein the recesses are oriented in an axial direction of the ring press and are spaced apart from one another in a circumferential direction of the ring press wherein the mounting section and the work section are formed on two opposite sides, with respect to a radial direction of the ring press, wherein the plurality of tools are fixed in the ring press by the mounting sections, wherein the ring press is configured to move each tool of the plurality of tools in either of two opposite directions of movement, the opposite directions of movement following straight lines and the directions of movement of all tools of the plurality of tools intersecting in one point, whereby the ring press manufactures the exhaust gas converter with a provided cylindrical metal pipe and cylindrical substrate surrounded in a substrate circumferential direction by a mat mount, the cross-section of the substrate including the mat mount being smaller or equal to a cross-section of the metal pipe with the substrate deposited with the mat mount surrounding the substrate inside the metal pipe by exerting a compression force on the metal pipe with tools, the compression force being directed in a radial direction of the metal pipe for reducing the cross-section of the metal pipe to a desired size, wherein regions to which a compression force is applied alternate along a metal pipe circumferential direction with regions to which no compression force is applied; and wherein a number of the regions to which no compression force is applied exceeds a number of the tools used for applying the compression force.