DE102005023168B4 - exhaust gas purification device - Google Patents

Abstract

method for mounting an exhaust gas purification device for internal combustion engines, in particular in the form of a diesel particulate filter and / or catalyst with a casing (10), consisting of two housing half-shells (1, 2), which increase the stiffness transverse to the longitudinal axis Have beads (3) or ribs (3) with a variable cross-section, in an assembly tool characterized in that the housing half-shells (1, 2) in the assembly tool to the monolith with the mat and the wire mesh are placed, while during the approach of the assembly tool the housing half shells (1,2) through the beads (3) or ribs (3) in the respectively required Position of the mounting tool are brought.

Description

described is a method for assembling an exhaust gas purification device for internal combustion engines, in particular in the form of a diesel particulate filter and / or catalyst consisting of two housing half shells.

catalysts and diesel particulate filters are two types of exhaust gas purification devices. These exhaust gas purification devices usually include one within a metal case fortified monolithic structure, being between the monolithic Structure and the walls of the housing one Storage mat is arranged. To catalysts and diesel particulate filters to manufacture with monoliths, it is necessary the monoliths in the housing against mechanical To protect stress. This is generally done by so-called storage mats, optionally in combination with wire mesh. support mats decouple the monolith against the metallic housing and take care of the long-term positioning of the monolith in the housing.

The Shell construction of the housing the emission control devices is usually made of a monolith, a mat, optionally wire knit and two half shells produced. This system is mounted in the so-called Canning process: The Canningverfahren, so the wrapping of the monolith in one Half-shell housing takes place by means of a sheath made of a wire mesh and / or a mat. The sheathing of the monolith serves as protection damage and for positioning within the housing half-shells. In the housing half shells the monolith is inserted with mat and / or wire mesh. For receiving the radial as well as the axial bearing forces, for Compensation of the different thermal expansion coefficients of the housing and the monolith and to achieve a sufficient seal between the outside of the monolith and the housing is the monolith with a sheath made of a knitted wire fabric, a mat or the like provided. The monolith will be in the Housing shell inserted and the other housing half shell hung up. Both housing half shells are pressed together with hydraulic presses and gas-tight at their contact surfaces welded.

In the DE 44 39 685 A1 are provided for increased rigidity of the housing shell outside beads. A higher strength of a container with the same material requirement by ribs with a variable cross section discloses the DE 197 33 589 A1 ,

The JP 07-180 544 A shows a housing for one Exhaust gas purification device, in particular in the form of a catalyst, consisting of two housing half-shells, the transverse to the longitudinal axis Have ribs.

The DE 80 19 814 U1 describes a catalyst housing with pre-pressed beads. In addition, prefabricated grooves are arranged in the lateral surface of the catalyst block. The beads in the housing and the grooves in the catalyst block are thus used by the filling ceramic mass in addition to their task of sealing even for additional support for the overall device in the housing. However, the shell shape often presents difficulties in process safety due to the fixed geometry.

It is therefore an object of the present invention, a self-controlled Centering function of the housing halves to create in the canning process. The housing half shells are according to the invention with beads or ribs with variable Cross section provided. The cross section of the beads or ribs will adapted to the respective requirements of the housing, wherein the cross section of the Beading or rib in its geometry runs unevenly to the position in the To ensure negative form of assembly or Canningwerkzeuges. The negative mold of the Canning tool must be the beads or ribs exactly match. By the respectively corresponding negative forms are the housing half shells while the closing process automatically move to the right position in the Canning Tool. The invention thus provides a housing for an exhaust gas purification device whose optimized housing geometry leads to greater process reliability leads, because the housing half shells automatically assume the optimal alignment within the Canning tool.

in the Result is thereby the danger that the housing half-shells while of the closing process in the canning process, reduced. The present assembly procedure is also non-circular Monolith cross sections applicable. The overall system can thus be in oval, elliptical or similar Molds are produced, the method of assembling a Emission control device in half-shell construction, consisting of the system monolith, mat, wire mesh and casing, one Process-reliable production of the entire system independent of the cross-sectional shape represents. The overall system may be in cross-section of its form of deviate from the ideal circular shape or the circular cross-section exhibit.

moreover can the housing half shells according to the invention contribute to a reduction in wall thickness, as the transverse corrugations or Ribs to a higher one Lead rigidity. The housing half shells are positioned above and below or respectively laterally.

In usually the housing half shells at least almost preformed to its final shape before its edge areas brought into their connection position and connected to each other, in particular welded. If an oval, elliptical or similar cross section produced be, so the half-shells are bent at least approximately in a U-shape.

to better positioning of the housing half-shells in the Canning tool, the beads or ribs are with a changing Cross-section provided so that a self-centering the respective half-shell in the Canningwerkzeug during the closing process results.

Next The stiffening function of the transverse corrugations or ribs will be particular here the self-controlled centering function resulting from the over changing course Cross-sectional geometry of the beads or ribs, in the respective tool halves while highlighted by the canning process. The tool halves have the corresponding negative shape of the housing half shells and associated the respective beads or ribs, so that the housing halves while the closing process automatically move into the correct position and thus the process reliability guaranteed is.

The two composite housing half shells have no appreciable internal before and after welding Tensions on which a restoring force trigger and could affect the bearing gap accuracy.

The Invention is described below with reference to the drawings embodiments described in more detail.

It demonstrate:

1 an inventive exhaust gas cleaning housing ( 1 . 2 ) in a perspective view from above with transverse beads ( 3 )

2 a radial cross section of the exhaust gas cleaning housing ( 1 . 2 )

3 an axial longitudinal section AA of the exhaust gas cleaning housing ( 1 . 2 )

4 an axial longitudinal section BB of the exhaust gas cleaning housing ( 1 . 2 )

5 a housing half shell ( 2 ) with an alternative embodiment of the transverse beads ( 3 ) in perspective view

6 a housing half shell ( 1 ) with a further alternative embodiment of the cross beads ( 3 ) in perspective view on the basis of 1 is a first embodiment of a housing according to the invention ( 10 ) of an exhaust gas purification device explained. The housing half-shells ( 1 . 2 ) are close in the overlap area ( 4 ) connected with each other. The overlap area ( 4 ) is along the longitudinal axis of the housing ( 10 ) welded. Each of the two housing halves ( 1 . 2 ) has stiffening, as well as during the Canningprozesses centering beads ( 3 ) transverse to the longitudinal axis, as shown here on the upper ( 1 ) and lower shell ( 2 ) of the housing ( 10 ).

The cross section of the housing ( 10 ), exemplified as an elliptical embodiment, shows the 2 ,

The axial section AA of 3 shows an embodiment of the housing half-shells ( 1 . 2 ) with cross beads ( 3 ) and the overlap area ( 4 ) of the two housing half-shells ( 1 . 2 ). The overlapping areas ( 4 ) of the housing half-shells ( 1 . 2 ) are connected by welding technology. The overlap ( 4 ) of the edge regions to be connected allow greater tolerances of the monolith and the housing half-shells ( 1 . 2 ) without any effort.

The 4 with the axial longitudinal section BB, shows the cross beads ( 3 ) of the housing half-shells ( 1 . 2 ) to each other. In the plan view, an embodiment of the changing over its course cross-sectional geometry of the beads ( 3 ). In addition to the stiffening function of the cross beads ( 3 ) is characterized by the changing over its course cross-sectional geometry of the beads ( 3 ) a self-controlled centering function of the housing half-shells ( 1 . 2 ) during the canning process. The Canningwerkzeug has appropriate negative forms of the respective beads ( 3 ) of the housing half shell ( 1 . 2 ) on.

As a result, the housing halves ( 1 . 2 ) automatically in the correct position during the closing process.

Further possible embodiments of the cross beads ( 3 ) for self-controlled positioning in the Canningwerkzeug show the housing shells ( 1 . 2 ) of the 5 and 6 ,

Claims (1)

Method for mounting an exhaust gas purification device for internal combustion engines, in particular in the form of a diesel particulate filter and / or catalyst with a housing ( 10 ), consisting of two housing half-shells ( 1 . 2 ), which are used to increase the rigidity transversely to the longitudinal axis ( 3 ) or ribs ( 3 ) having a variable cross-section, characterized in an assembly tool characterized in that the housing half-shells ( 1 . 2 ) are placed in the assembly tool around the monolith with the mat and the wire mesh, wherein during the approach of the mounting tool, the housing half-shells ( 1 . 2 ) through the beads ( 3 ) or ribs ( 3 ) are brought into the respective required position of the mounting tool.