Housing, in particular for a heat exchanger, and method of its production

Abstract

The application relates to a housing, in particular for a heat exchanger in an exhaust system of a motor vehicle, comprising a jacket with two joining margins which are joined along a joining line, the jacket having two connecting openings formed by recesses in the joining margins. The application also relates to a method of producing a housing by means of the following steps: First it is determined under which angle relative to each other two connecting openings of the housing are to be arranged with respect to a central line of the housing. Then the shape of a jacket is determined, taking into account the axial distance between the connecting openings. Subsequently the jacket is cut out from a sheet of material, with recesses which later form the connecting openings being cut out on at least one of two joining margins which later are adjoining each other. Thereafter the jacket is bent such that the two joining margins rest at each other. Finally the joining margins are connected with each other.

Description

CROSS-REFERENCE

Foreign priority is hereby claimed under 35 U.S.C. §119 to DE 10332537.9 which was filed in the Federal Republic of Germany on Jul. 17, 2003 and is incorporated by reference herein.

FIELD OF THE DISCLOSURE

The invention relates to a housing, in particular for a heat exchanger in an exhaust system of a motor vehicle, as well as to a method of producing such a housing.

BACKGROUND OF THE DISCLOSURE

With a housing of this type there is often the problem that connections for a component arranged in the housing, for instance for the heat exchanger, are to be led through out of the housing in different orientations. A very good example for this are the housings of heat exchangers used in the exhaust line of a motor vehicle. The heat exchangers mostly serve for taking away heat from the exhaust stream, which heat for instance can be used to heat the interior space of the motor vehicle. Although a high number of units of the heat exchangers is demanded, the number of units of each individual embodiment which has to be made available comparably low. This is due to the fact that the connections of the heat exchanger have to be individually arranged with every type of vehicle where such a heat exchanger is employed. This results in that a multitude of differing housing types has to be made available. The costs per unit are increased thereby.

It is the object of the invention to provide a housing which on the one hand has an as simple a construction as possible, so that the manufacturing costs will be low, and on the other hand allows a high flexibility with respect to the orientation of the connections that are to be passed through it. It is also the object of the invention to provide a method of producing such a housing.

SUMMARY OF THE DISCLOSURE

In order to solve this object there is provided a housing, in particular for a heat exchanger in an exhaust system of a motor vehicle, comprising a jacket with two joining margins which are joined along a joining line, the jacket having two connecting openings formed by recesses in the joining margins. The jacket can be cut or stamped for example from sheet metal with low expenditure. In a technically simple manner, the connecting openings are formed by recesses in the joining margins. In so doing, almost any orientation of the connecting openings can be achieved by a suitable selection of the shape of the jacket. If with a cylindrical housing the two connecting openings lie on the same radius, when viewed along a longitudinal axis of the housing, i.e. are arranged on a generatrix of the jacket, then the jacket has the shape of a rectangle, so that the joining line formed by the joining margins extends in parallelism to the central line of the jacket. In case that the two connecting openings are arranged so as to have a rotational offset relative to each other, however, the jacket can be made so as to have such a shape that the joining line extends oblique relative to the central line, for instance in the nature of a helical line about the cylinder-shaped jacket, with the pitch of the helical line being selected such that the two connecting openings lie on the joining line.

In order to solve the above-mentioned object there is also provided a method of producing a housing by means of the following steps: First it is determined under which angle relative to each other two connecting openings of the housing are to be arranged with respect to a central line of the housing. Then the shape of a jacket is determined, taking into account the axial distance between the connecting openings. Subsequently the jacket is cut out from a sheet of material, with recesses which later form the connecting openings being cut out on at least one of two joining margins which later are adjoining each other. Thereafter the jacket is bent such that the two joining margins rest at each other. Finally the joining margins are connected with each other. This method always uses the same method steps independently of the respective arrangement of the connecting openings, so that the method can be performed at favourable costs. It would even be conceivable to manufacture different embodiments of the housing on one and the same production line in direct succession, as these only differ in terms of the form of the blank of the jacket. The various cuts to size can be performed in a flexible manner by laser cutting, for instance.

Advantageous designs of the invention will be apparent from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in the following with the aid of two embodiments illustrated in the attached drawings in which:

FIG. 1 shows in a top view a housing with an inserted heat exchanger according to a first embodiment of the invention;

FIG. 2 shows in a top view a housing with an inserted heat exchanger according to a second embodiment of the invention;

FIG. 3 shows a first step during production of the housings according to the invention;

FIG. 4 shows a second step during production of the housing according to the first embodiment;

FIG. 5 shows a second step during production of the housing according to the second embodiment;

FIG. 6 shows a further step during production of the housings according to the invention; and

FIG. 7 shows a section along plane VII-VII of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a housing 10 which receives a heat exchanger 5 arranged in the interior of the housing and indicated in broken lines. The heat exchanger has two connecting sleeves 7 which can be connected with a heat exchanger circuit (not illustrated).

A component of the housing 10 is a jacket 12 which is cylindrical and has a central line M. When laid out flat in a plane, the jacket 12 has the shape of a parallelogram. The jacket 12 is formed in that it has been bent into the cylindrical shape and two opposite edges—designated as joining margins 14, 16—have been connected with each other. The line of contact of the two joining margins 14, 16 defines a joining line along which the two joining margins 14, 16 are welded to each other. This is symbolised by a weld seam 18. The two remaining margins of the parallelogram each define a front face 20 to which a (not illustrated) cover member can be mounted. Then the housing will be completely closed.

For the passage of the connecting sleeves 7 through the housing, there are provided two connecting openings 24 formed by two opposite recesses 26, 28 in the joining margins 14, 16. The connecting openings 24 approximately have the shape of a circle so that each recess 26, 28 is more or less semicircular. It is to be seen that the diameter of the connecting openings 24 is larger that the diameter of the connecting sleeves 7. In this way there is realised a sufficient intermediate space between the connecting openings and the connecting sleeves, allowing a relative movement between heat exchanger 5 and housing 10 under differing thermal expansions.

With the embodiment according to FIG. 1, the joining line formed by the joining margins 14, 16 extends in parallelism to the central line M. In other words, the joining line corresponds to a generatrix of the cylindrical area of the jacket. It follows that the parallelogram shape of the laid-out jacket 12 is a rectangle. In the embodiment according to FIG. 2, however, the jacket 12 has the shape of a “conventional” parallelogram, where the corner angles are different in pairs. The joining line between the joining margins 14, 16 accordingly extends about the jacket as a helical line, i.e. extends oblique relative to the central line M. Therefore the connecting openings 24 are not any longer on one and the same radius with respect to the central line M, as is the case with the embodiment according to FIG. 1, but are on different radii. In the embodiment shown in FIG. 2 the two connecting sleeves 7 are aligned so as to have a 90° rotational offset relative to each other.

The production of the housing will now be explained with the aid of the FIGS. 3 to 7.

In a first step, a sheet of material 30 will be prepared (see FIG. 3). The jacket 12 will be cut out from this sheet at a later point in time. Advantageously sheet metal is used the properties of which are adapted to the expected application conditions of the housing.

In an intermediate step the parallelogram shape of the jacket 12 is determined. If there is to be produced a housing according to FIG. 1, for instance, the outline of the jacket is defined as the shape shown in FIG. 4, namely as a rectangle having the recesses 26, 28. If, on the other hand, a housing according to FIG. 2 is to be produced, the outline of the jacket is defined as the shape shown in FIG. 5, namely as a “conventional” parallelogram. The angle α, by which the corner angles of the parallelogram are larger or smaller than 90°, can be determined easily as a function of the desired rotational offset of the two connecting openings 24 relative to each other in the circumferential direction, of the distance A between the two connecting openings in axial direction as well as of the circumference B of jacket 12.

When the contour of jacket 12 has been determined, the latter is cut from the sheet of material 30, as is shown in FIGS. 4 or 5.

In a next method step, the cut-out jacket 12 is bent around the heat exchanger 5 (see FIG. 6) so that the sleeves 7 come to lie in the connecting openings 24 formed by the recesses 26, 28. An insulation and damping material can be arranged between jacket 12 and heat exchanger 5.

According to an alternative method the cut-out jacket 12 is first bent so as to take up its final shape. Then the heat exchanger, wrapped up in the insulation layer, is inserted into the jacket which is slightly re-opened for that purpose. Subsequently the jacket is closed again (the spring-back of the material may possibly be sufficient for this), and the joining margins are connected with each other.

Finally the joining margins 14, 16 are connected with each other through weld seam 18 (see FIG. 7). Thus, the jacket 12 of the housing will be closed. In practice, the two joining margins 14, 16 in most cases will not be butt-jointed with each other, but rest at each other with an overlap. In this way the tolerances of the jacket and of the heat exchanger can be easily compensated. Moreover, welding the joining margins to each other is facilitated.

Cover members can then be mounted to the front faces 20 of the cylinder formed by the jacket 12. The housing is then completely closed off. Through the orientation of the jacket 12 relative to the cover members, i.e. by rotation about axis M, the orientation of the connecting sleeves 7 can be adjusted as desired.

According to a (not illustrated) further embodiment the connecting openings 24 can each be constituted by a single recess provided only on one of the two joining margins 14, 16. Here, the two recesses can either be provided in only one of the joining margins, or there is one recess in each joining margin.

A particular advantage of the housing and the method according to the invention is that the connecting sleeves 7 can be readily mounted, in particular welded, to the heat exchanger 5 prior to its insertion in the housing 10. As the sleeves 7 are easily accessible, there are no quality problems on providing the respective weld seams. Moreover, the connecting sleeves 7 can be welded to the heat exchanger 5 in any orientation, as is shown in FIG. 1. In connection with the variable orientation of the connecting sleeves 7 relative to each other, a maximum freedom arises in terms of connecting the heat exchanger with a heat exchanger circuit. Of course, the connecting sleeves can also be configured so as to be straight or bent with an angle other than 90°.

With both embodiments there has been illustrated as an example a cylindrical housing with a jacket in the shape of a parallelogram, because this is better to understand than more complicated geometric shapes. Basically the principle according to the invention may be applied to housings of any cross-section, for instance oval or rectangular, even with a changing cross-section. The jacket basically can have any shape; the only condition is that this shape when bent together encloses the heat exchanger and can be closed along a joining line on which the connecting sleeves are provided. The joining margins do not have to be straight, but may extend with a curvature, resulting in a correspondingly curved extension of the joining line.

Claims

1. A housing, in particular for a heat exchanger in an exhaust system of a motor vehicle, comprising a jacket with two joining margins which are joined along a joining line, the jacket having two connecting openings formed by recesses in the joining margins.

2. The housing according to claim 1, characterised in that the connecting openings consist of two opposite recesses in the joining margins.

3. The housing according to claim 1, characterised in that the joining margins are welded to each other.

4. The housing according to claim 1, characterised in that the connecting openings are arranged in different angular orientations when viewed along a central line of the housing.

5. The housing according to claim 1, characterised in that the jacket is made from sheet metal.

6. The housing according to claim 1, characterised in that the jacket is connected at its front faces to one cover member each.

7. The housing according to claim 1, characterised in that the jacket, when laid out flat, has a parallelogram shape.

8. The housing according to claim 1, characterised in that it is cylindrical.

9. A method of producing a cylindrical housing, comprising:

it is determined under which angle relative to each other two connecting openings of the housing are to be arranged with respect to a central line of the housing;

the shape of a jacket is determined, taking into account the axial distance between the connecting openings;

the jacket is cut out from a sheet of material, with recesses which later form the connecting openings being cut out on at least one of two joining margins which later are adjoining each other;

the jacket is bent such that the two joining margins rest at each other;

the joining margins are connected with each other.

10. The method according to claim 9, characterised in that the jacket is cut out from sheet metal.

11. The method according to claim 10, characterised in that the jacket is punched out.

12. The method according to claim 10, characterised in that the jacket is laser cut.

13. The method according to claim 9, characterised in that the two joining margins are welded to each other.

14. The method according to claim 9, characterised in that after bending the jacket, a heat exchanger is inserted by slightly re-opening the jacket for a short time.

15. The method according to claim 14, characterised in that the heat exchanger is provided with connecting sleeves.

16. The method according to claim 15, characterised in that the connecting sleeves are welded to the heat exchanger in an orientation which is adapted to the particular application conditions.