Method for producing at least one ash-forming means for a particulate filter of an exhaust gas system of a gasoline engine

Abstract

A method is provided for producing at least one ash-forming element (1) for a particulate filter of an exhaust gas system of a gasoline engine or diesel engine. The method includes providing of a strip-shaped center layer (3), and making receiving holes (6) in the center layer (3). The method continues by providing of a strip-shaped bottom layer (4), and permanently connecting of the bottom layer (4) to the center layer (3). The method proceeds by filling the receiving holes (6) of the center layer (3) with ash-forming components (2), providing a strip-shaped top layer (5), and permanently connecting the top layer (5) to the center layer (3). The method then includes punching out of at least one ash-forming means (1) from the wafer, and making throughflow openings (7) in regions where there are no ash-forming components (2).

Claims

1. A method for producing at least one ash-forming means for a particulate filter of an exhaust gas system of a gasoline engine or diesel engine, the method comprising: providing a strip-shaped center layer; making receiving holes in the center layer; providing a strip-shaped bottom layer; permanently connecting the bottom layer to the center layer; filling the receiving holes of the center layer with the ash-forming components; providing a strip-shaped top layer permanently connecting the top layer to the center layer to form a wafer; punching out of at least one ash-forming means from the wafer; and making throughflow openings in those regions of the ash-forming means in which there are no ash-forming components.

2. The method of claim 1, wherein the center layer is made from paper or cardboard.

3. The method of claim 2, wherein the bottom layer is made from paper or cardboard.

4. The method of claim 3, wherein the top layer is made from paper or cardboard.

5. The method of claim 1, wherein the bottom layer and the top layer are connected to the center layer by adhesive bonding.

6. The method of claim 1, wherein the receiving holes are made in the center layer by being punched out.

7. The method of claim 1, wherein the throughflow openings are made in the at least one ash-forming means by being punched out.

8. The method of claim 7, wherein the at least one ash-forming means is punched out of the wafer with a contour so that that the ash-forming means can be used as a spacer element between two components of the exhaust gas system that are provided for conducting through exhaust gases.

9. The method of claim 1, wherein the at least one ash-forming means is punched out of the wafer with an annular or circular contour.

10. The method of claim 1, wherein a plurality of ash-forming means are punched out of the wafer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a flow chart that illustrates the steps of a method for producing an ash-forming means for a particulate filter of a gasoline engine or diesel engine from a wafer with ash-forming components.

(2) FIG. 2 is an enlarged, diagrammatically greatly simplified sectional view of a part of the ash-forming means produced by the method shown in FIG. 1.

DETAILED DESCRIPTION

(3) An ash-forming means 1 for a particulate filter of a gasoline engine or diesel engine has ash-forming components 2, as shown in FIG. 2. The ash-forming means 1 has a center layer 3, a bottom layer 4 and a top layer 5 that are connected to one another.

(4) An ash-forming means 1 of this type is produced from a wafer in the method described in the following text. In a first step 100, a strip-shaped center layer 3 is provided and is produced from paper or cardboard. Receiving holes 6 for receiving the ash-forming components 2 are made in the center layer 3. The receiving holes 6 can be produced by punching in a particularly simple way. The shape of the receiving holes 6 can be selected in any desired way. For example, receiving holes can be circular, oval or polygonal.

(5) In a second step 101, a bottom layer 4 is provided and also preferably is a strip produced from paper or cardboard. The bottom layer 4 is connected permanently to the center layer 3 in a suitable way, such as by adhesive bonding.

(6) In a further step 102, the receiving holes 6 of the center layer 3 are filled with ash-forming components or ash components 2, such as Mg, Ca, Al, Fe, MgO, CaO, Al.sub.2O.sub.3 and FeO. The layer thickness of the center layer 3 and the number and size of the receiving holes 6 that are punched into the center layer 3 define the quantity of ash-forming components 2 that can be received in the center layer 3.

(7) After the ash-forming components 2 are introduced into the receiving holes 6 of the center layer 3, in a following step 103, a top layer 5 is provided. The top layer 103 is strip-shaped and also preferably is produced from paper or cardboard. The receiving holes 6 of the center layer 3 are closed by the top layer 5. The top layer 5 can be bonded adhesively to the center layer 3. As a result, a three-layer wafer is provided, in which the ash-forming components 2 are packed.

(8) The wafer then is punched out in step 104 so that the ash-forming means 1 can be obtained with the desired contour. A plurality of ash-forming means 1 can be punched out from the wafer, so that plural ash-forming means 1 can be produced from a single wafer in a very simple and inexpensive manner. Each ash-forming means 1 punched out from the wafer is perforated in a step 105 to form throughflow openings 7 in which there are no ash-forming components 2. The throughflow openings 7 make an effective throughflow of the ash-forming means 1 by way of hot exhaust gases possible during use of the ash-forming means 1. The shape of the throughflow openings 7 can be selected in any desired way. For example, the throughflow openings 7 may be circular, oval or polygonal.

(9) It has proven expedient that the ash-forming means 1 is punched out of the wafer with a contour such that the ash-forming means 1 can be used as a spacer element between two components of the exhaust gas system that are provided for conducting through exhaust gases. For example, the at least one ash-forming means 1 can be punched out from the wafer with an annular or circular contour.

(10) The ash-forming means 1 produced in the above-described way can be arranged at an inlet of a particulate filter of an exhaust gas system of a gasoline engine or at an inlet or outlet of a catalytic converter of the exhaust gas system or between the particulate filter and the catalytic converter. The ash-forming means 1 burns after the first start of the gasoline engine. As an alternative, the step can also be carried out by an external burner. In both cases, the ash-forming components 2 are released which, as a result, can form a filter cake for the particulate filter of the gasoline engine or diesel engine.