Method for manufacturing a catalytic converter housing arrangement with at least one sensor carrier for an exhaust system of a vehicle

Abstract

A method is provided for manufacturing a catalytic converter housing arrangement with at least one sensor carrier for an exhaust system of a vehicle. The method includes the steps of: a) providing at least one sensor carrier sheet metal blank (42); b) forming at least one sensor mounting opening (48) in the sensor carrier sheet metal blank (42) by flow drilling such that a length (L) of the opening is greater than a thickness (D) of the material of the sensor carrier sheet metal blank (42) before step b) is carried out; and c) preparing an internal thread in the at least one sensor mounting opening (48) for providing a sensor carrier.

Claims

1. A method for manufacturing a catalytic converter housing arrangement with at least one sensor carrier for an exhaust system of a vehicle, the method comprising the steps of: providing a catalytic converter housing, made of a sheet metal material, with at least one sensor opening; providing at least one sensor carrier sheet metal blank with an initial sensor carrier sheet metal blank material thickness by punching or cutting the sensor carrier sheet metal blank out of a basic sheet metal material and then transforming the sensor carrier sheet metal blank to a desired shape, such that an edge area of the sensor carrier sheet metal blank is shaped for being in contact with the catalytic converter housing in an entire area surrounding the at least one sensor opening; forming a sensor mounting opening in the provided sensor carrier sheet metal blank having the desired shape by flow drilling such that a length of the sensor mounting opening is greater than the initial sensor carrier sheet metal blank material thickness; preparing an internal thread in the sensor mounting opening for providing the at least one sensor carrier; fixing the sensor carrier sheet metal blank having the desired shape on the catalytic converter housing before or after forming the sensor mounting opening and before preparing the internal thread.

2. A method in accordance with claim 1, wherein the step of fixing the sensor carrier sheet metal blank comprises fixing by welding.

3. A method in accordance with claim 2, wherein the step of fixing the sensor carrier sheet metal blank comprises placing the sensor carrier sheet metal blank on an outer surface of the catalytic converter housing and fixing by fillet welding.

4. A method in accordance with claim 2, wherein the step of fixing the sensor carrier sheet metal blank comprises inserting the sensor carrier sheet metal blank into a sensor carrier depression formed on the catalytic converter housing in an area of a sensor opening and fixing by I-profile seam welding.

5. A method in accordance with claim 1, wherein the catalytic converter housing is provided with an essentially cylindrical housing central area and an essentially conical housing end area at at least one end of the housing central area.

6. A method in accordance with claim 5, wherein the catalytic converter housing is provided with at least one sensor opening in the housing central area.

7. A method in accordance with claim 5, wherein the catalytic converter housing is provided with at least one sensor opening in at least one housing end area.

8. A method in accordance with claim 5, wherein the catalytic converter housing comprises at least one sensor opening in at least one transition area from the housing central area to a housing end area.

9. A catalytic converter arrangement for an exhaust system of a vehicle, the catalytic converter arrangement comprising a catalytic converter housing arrangement manufactured with a method comprising the steps of: providing a catalytic converter housing, made of a sheet metal material, with at least one sensor opening; providing at least one sensor carrier sheet metal blank with an initial sensor carrier sheet metal blank material thickness by punching or cutting the sensor carrier sheet metal blank out of a basic sheet metal material and then transforming the sensor carrier sheet metal blank to a desired shape, such that an edge area of the sensor carrier sheet metal blank is shaped for being in contact with the catalytic converter housing in an entire area surrounding the at least one sensor opening; forming a sensor mounting opening in the provided sensor carrier sheet metal blank having the desired shape by flow drilling such that a length of the sensor mounting opening is greater than the initial sensor carrier sheet metal blank material thickness; preparing an internal thread in the sensor mounting opening for providing the at least one sensor carrier; fixing the sensor carrier sheet metal blank having the desired shape on the catalytic converter housing before or after forming the sensor mounting opening and before preparing the internal thread.

10. A catalytic converter arrangement in accordance with claim 9, further comprising at least one catalytic converter unit carried in the catalytic converter housing arrangement.

11. A catalytic converter arrangement in accordance with claim 9, further comprising: a sensor carried by a thread meshing with the internal thread in the sensor mounting opening.

12. A catalytic converter arrangement in accordance with claim 11, wherein the sensor is a temperature sensor.

13. A catalytic converter arrangement in accordance with claim 11, wherein the sensor is a gas sensor.

14. A catalytic converter arrangement in accordance with claim 13, wherein the sensor is an O.sub.2 sensor or NO.sub.x sensor.

15. A method for manufacturing a catalytic converter housing arrangement, the method comprising the steps of: providing a housing defining a sensor opening; providing a blank separate from said housing, said blank having a first shape and an initial thickness; transforming the blank to a second shape separate from said housing, such that an edge area of the blank is shaped for being in contact with the housing in an entire area surrounding the sensor opening; forming a mounting opening in the blank having the second shape by flow drilling such that an axial length of the sensor mounting opening is greater than the initial thickness of the blank; fixing the blank having the second shape on the housing before or after forming the mounting opening; preparing an internal thread in the mounting opening after said forming and said fixing.

16. A method in accordance with claim 15, wherein: said providing of the blank is performed by punching or cutting the blank out of sheet metal material into the first shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a longitudinal sectional view of a catalytic converter arrangement known from the state of the art;

(3) FIG. 2 is a sectional view of a sensor carrier sheet metal blank;

(4) FIG. 3 is the sensor carrier sheet metal blank according to FIG. 2 when the flow drilling operation is being carried out;

(5) FIG. 4 is the flow drilled sensor carrier sheet metal blank during a thread-cutting operation;

(6) FIG. 5 is a sensor carrier on a catalytic converter housing with a sensor being carried thereon;

(7) FIG. 6 is a sensor carrier fixed on a catalytic converter housing with a fillet weld;

(8) FIG. 7 is a sensor carrier fixed on a catalytic converter housing with an I-profile weld;

(9) FIG. 8 is a sensor carrier fixed in the area of a housing central area;

(10) FIG. 9 is a sensor carrier fixed in a transition area from a housing central area to a housing end area; and

(11) FIG. 10 is a sensor carrier fixed in a housing end area.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) Referring to the drawings, it should be noted, before a method for manufacturing a catalytic converter housing arrangement, especially a sensor carrier, will be described in detail below, that the configuration of a catalytic converter housing arrangement to be manufactured in this manner or of a catalytic converter arrangement comprising same may, in principle, be such as it is shown in FIG. 1 described above with reference to FIG. 1. Therefore, using the reference numbers already used in the introduction, reference will also be made in the context of the present invention to the general configuration of such a catalytic converter housing arrangement or catalytic converter arrangement as it is shown in FIG. 1.

(13) FIG. 2 shows a sensor carrier sheet metal blank 42 generally designated by 42 in contact with an outer surface 44 of the catalytic converter housing 19, here of the housing central area 14. The sensor carrier sheet metal blank 42 may be provided as an initially essentially flat component, for example, by punching or cutting out of a basic sheet metal material, for example, a metal sheet, and then transformed to the shape desired for the subsequent use, e.g., by pressing, bending or deep-drawing. The sensor carrier sheet metal blank 42 is thus provided with an edge area 46 shaped for being in contact with the catalytic converter housing 19 such that this edge area 46 can be in contact with the outer surface 44 in the entire area surrounding the sensor opening 38.

(14) In a then following working step, shown in FIG. 3, a sensor mounting opening 48 is prepared in the sensor carrier sheet metal blank 42 by flow drilling. Flow drilling, generally also known as thermal friction drilling, is carried out with the use of a mandrel-like tool 50 heating to a high temperature and rotating about its longitudinal axis. The tool 50 is pressed against the sensor carrier sheet metal blank 42. The metallic material of the sensor carrier sheet metal blank 42 is locally melted in the process in the area acted on by the tool 50 displaced to the side. An area of thickened material 52 surrounding the sensor mounting opening 48 is formed in the process on both sides of the sensor carrier sheet metal blank 42, so that the sensor mounting opening 48 passing through this area of thickened material 52 has an opening length L that is greater than the initial thickness D of the sheet metal material of the sensor carrier sheet metal blank 42. The sensor carrier sheet metal blank 42 may also be prepared with an essentially flat contact surface 54 for a sensor by the tool 50 in the area of thickened material 52 during the flow drilling. As will be shown below, the contact surface 54 is located on the outer side in the prepared catalytic converter housing arrangement 12.

(15) In a next working step, shown in FIG. 4, an internal thread is cut in the sensor mounting opening 48 formed in the area of thickened material 52. The internal thread 56 may be prepared by a corresponding tool 58 immediately after preparation of the sensor mounting opening 38 in the still hot state of the sensor carrier sheet metal blank 42, or it may be prepared when the sensor carrier sheet metal blank 42 has already essentially cooled down.

(16) The sensor carrier sheet metal blank 42 is essentially finished after preparation of the internal thread 56, so that a sensor carrier generally designated by 60 is provided. This is fixed by welding in a working step shown in FIG. 5 with its edge area 46 on the outer surface 44 of the catalytic converter housing 19, of the housing central area 14 in the example being shown. In case of fixation by welding in the manner shown in FIGS. 5 and 6, the edge area 46 is placed on the outer surface 44, which is essentially free from steps, but is curved because of the tubular configuration of the housing central area 14. A weld 62, which surrounds the entire edge area 46 and thus connects this area to the catalytic converter housing 19, can be prepared by fillet welding in the angular transition area between the edge area 46 and the outer surface 44. A stable and especially gas-tight connection is thus established between the sensor carrier 60 and the catalytic converter housing 19.

(17) A sensor generally designated by 64 can then be screwed into the sensor carrier 60, so that an external thread 66 provided thereon meshes with the internal thread 56. The sensor 64 can be screwed in to the extent that a stop 68 provided on it, for example, as a hexagon insert bit comes into gas-tight contact with the contact surface 54 of the sensor carrier 60, optionally via the intermediary of a ring-shaped sealing element.

(18) When the sensor carrier 60 is manufactured or fixed, the different working steps described above may also be carried out in another chronological sequence. For example, after preparing the sensor carrier sheet metal blank 42 with the desired shape, this may be fixed to the catalytic converter housing 19 by welding. The sensor mounting opening 48 can then be prepared by flow drilling, and the internal thread 56 is then prepared in said opening. As an alternative, the sensor carrier sheet metal blank 42 could also be fixed on the catalytic converter housing 19 by welding when the sensor mounting opening 48 has been prepared in said sensor carrier sheet metal blank by flow drilling, but before the internal thread 56 is cut in the sensor mounting opening.

(19) FIG. 7 shows an alternative manner of connecting the sensor carrier 60 and the sensor carrier sheet metal blank 42, depending on the sequence of the working steps, on the catalytic converter housing 19. A sensor carrier depression 70 corresponding in its circumferential contour to the circumferential contour of the sensor carrier 60 and of the sensor carrier sheet metal blank 42 is provided on the catalytic converter housing 19, for example, on the housing central area 14 in this variant. The sensor carrier 60 or the sensor carrier sheet metal blank 42 is inserted into this sensor carrier depression 70, so that an intermediate space is left between the edge area 46 and a wall 72 surrounding the sensor carrier depression 70. An I-profile weld 64, also called two-sided full seam, which surrounds the entire edge area 46 and fills the intermediate space essentially completely, is prepared in this intermediate area. The edge area 46 of the sensor carrier 60 or of the sensor carrier sheet metal blank 42 thus passes essentially flush over into the outer surface 44 of the catalytic converter housing 19 essentially without a step, via the weld 74.

(20) FIGS. 8-10 show different ways of positioning a sensor carrier 60 on the catalytic converter housing 19. The positioning shown in FIG. 8 also corresponds essentially to the position provided for a sensor carrier in case of the configuration shown in FIG. 1. The sensor opening 38 is provided in the housing central area 14, especially in the area of the intermediate space 40 formed between the two catalytic converter units 20, 22. A sensor to be fixed on the sensor carrier 60 can protrude into this intermediate space 40 and detect the composition of the gas or the temperature of the gas in this area.

(21) The sensor carrier 60 is provided in a transition area 76 between the housing central area 14 and, for example, the housing end area 18 in the embodiment according to FIG. 9. The sensor opening 38 is formed in this variant, for example, partly in the housing central area 14 and partly in the housing end area 18. The edge area 46 of the sensor carrier 60 or of the sensor carrier sheet metal blank 42 is fixed, for example, by fillet welding on the outer surface 44 of the catalytic converter housing 19.

(22) The sensor carrier 60 or the sensor carrier sheet metal blank 42 is provided, for example, entirely on the housing end area 18 in the embodiment variant shown in FIG. 10. The sensor opening 38 is arranged entirely in the conical area of the housing end area 18.

(23) It is advantageous in case of the positioning of a sensor carrier 60 as shown in FIG. 9 to connect the different areas or components of the catalytic converter housing 19, i.e., the housing central area 14 and the housing end areas 16, 18, to one another, for example, by welding and/or press fit before the sensor carrier 60 is placed on the transition area 76. In the case of the positioning shown in FIGS. 8 and 10, the sensor carrier 60 can be fixed on the respective area or the respective component of the catalytic converter housing 19 before or after these areas or components of the catalytic converter hosing 19 are assembled.

(24) It should be noted that a plurality of sensor carriers 60 may be provided on the catalytic converter housing 19. For example, at least one sensor carrier 60 each may thus be provided on each of the two housing end areas 16, 18 in order to be able to detect, for example, the composition of the gas or the gas temperature in the area located upstream of the two catalytic converter units 20, 22 and in the area located downstream of the catalytic converter units 20, 22, or in order to be able to detect respective different measured variables in these areas. As an alternative or in addition, a plurality of sensor carriers 60 may also be provided on the housing central area 14, for example, following one another in the circumferential direction.

(25) Further, a plurality of sensor mounting openings, for example, two sensor mounting openings, may be provided next to one another on at least one of the sensor carriers, so that a plurality of sensors, which are configured, for example, for detecting different measured variables, can be carried on a single sensor carrier. The sensor carrier, on the one hand, and, on the other hand, the sensor opening provided, associated with same, on the catalytic converter housing, can have correspondingly larger dimensions in this case. Further, sensor carriers of different shapes may be provided on one catalytic converter housing in order to guarantee, for example, the suitable installation position for the respective sensors to be arranged there, depending on the installation location.

(26) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.