DESC:FIELD OF INVENTION

The present invention relates to mounting brackets used in automobiles. In particular, the present invention relates to mounting bracket for catalytic converters. More particularly, the present invention relates to mounting brackets for catalytic converter for obtaining thermal compliance in expansion direction and stiffness in other direction.

BACKGROUND OF THE INVENTION

Normally, the bracket for mounting the catalytic converters supports the exhaust system catalytic converter shell on the crankcase. The bracket used for mounting the catalytic converter is required to achieve contradictory requirements of thermal compliance in expansion direction and stiffness in other direction. Accordingly, this catalytic converter mounting bracket should fulfil the following requirements:

• Thermal compliance in the direction of the catalytic converter axis, and

• Fulfil natural frequency requirement in terms of stiffness in the transverse direction.

The catalytic converter mounting bracket is welded with the sides of the catalytic converter disposed in a transverse direction (i.e. bolt axis lies transverse to the axis of the catalytic converter) thereof.

Although, the targeted frequency can be achieved with the transversely oriented catalytic converter mounting bracket, substantially higher thermal stresses are induced on the catalytic converter mounting bracket due to the thermal expansion thereof.

Therefore, there is an existing need for improving the configuration of the catalytic converter mounting bracket used in automobiles, which can serve the contradictory requirements for thermal compliance and stiffness in different directions.
DISADVANTAGES WITH THE PRIOR ART

It is clear from the above description of the existing configuration of the catalytic converter mounting bracket that higher stresses are developed on the catalytic converter shell near the side supported bracket welds, because the bracket axis is transverse to the axis of the catalytic converter.

It was observed during the stress analysis by drawing the contour plot (maximum stress or Von Mises stress) that in the existing configuration of the catalytic converter mounting bracket, the maximum stress is normally in a range of 43 to 127 MPa.

This higher stress is not acceptable and needs significant improvement to avoid excessive stresses generated near the sides of the catalytic converter mounting bracket which may lead to breakage thereof from the catalytic converter shell.

Moreover, the existing configuration of the catalytic converter mounting bracket does not distribute the load in sufficiently large area, thereby leads to undesirable stress concentration therein.

DESCRIPTION OF THE PRESENT INVENTION

In order to improve the existing configuration of the catalytic converter mounting bracket in which higher stresses are developed on the catalytic converter shell near the side supported bracket welds due to the bracket axis being disposed transverse to the axis of the catalytic converter, the present envisages to suitably change the orientation of the catalytic converter mounting bracket by making it parallel to the axis of the catalytic converter, i.e. the bolt axis of the catalytic converter is made parallel to the catalytic converter axis. This modified catalytic converter mounting bracket configuration helps in achieving the desired thermal compliance in the direction of expansion as well as the stiffness in the other direction.

In this modified configuration, the catalytic converter mounting bracket orientation effectively meets the requirements of thermal compliance as well as the vibrations generated therein.

Accordingly, the catalytic converter mounting bracket has thermal compliance in the direction of expansion of the catalytic converter and stiffness in the other direction. Therefore, the catalytic converter mounting bracket configured in accordance with the present invention:

• Meets the natural frequency requirement due to better stiffness in transverse direction.

• Induces lower thermal stresses due to reduction of stiffness in the direction of expansion (along the axis of the catalytic converter).

• Induces lower stresses due to vibrations, because of the natural frequency being kept above the engine operating range of frequencies.

• Offers excellent load distribution on the catalytic converter shell.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a mounting bracket for the catalytic converter, which facilitates thermal compliance in the expansion direction.

Another object of the present invention is to provide a mounting bracket for the catalytic converter, which fulfils natural frequency requirements in the transverse direction.

Still another object of the present invention is to provide a mounting bracket for the catalytic converter, which induces lower thermal stresses due to vibrations therein.
Yet another object of the present invention is to provide a mounting bracket for the catalytic converter, which induces better stiffness in the direction of expansion.

A further object of the present invention is to provide a mounting bracket for the catalytic converter, which distributes the load in a substantially larger area.

A still further object of the present invention is to provide a mounting bracket with orientation in the deformation direction of the catalytic converter axis.

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a bracket for mounting the catalytic converter on an automobile engine, wherein the bracket prevents stress concentration in the joint thereof with the catalytic converter shell.

Typically, the bracket fulfils thermal compliance in the axial direction of the catalytic converter.

Typically, the bracket fulfils the natural frequency requirements in terms of the stiffness in the transverse direction of the catalytic converter.

Typically, the bracket orientation is in the direction of deformation of the catalytic converter.

Typically, the bracket axis is parallel to the catalytic converter axis.

Typically, the bracket comprises wide flanges providing large area for substantially improved load distribution on the shell of the catalytic converter.
Typically, the bracket body is configured in ‘C’ section with outwardly extended flanges to be joined on the catalytic converter shell.

Typically, the bracket mounting bolt axis is parallel to the catalytic converter axis.

Typically, the bracket is joined to the catalytic converter shell by means of welded joints.

Typically, the stress concentration in the bracket joint to the catalytic converter shell is reduced by approximately 50 to 75% in comparison to the bracket having its axis disposed perpendicular to the catalytic converter axis.

Typically, the value of Von Mises Maximum stress in the vicinity of the joint of the bracket to the catalytic converter shell is in a range of 20 to 30 MPa.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1 shows the catalytic converter fitted by means of the conventional mounting bracket for connection to a silencer in an automobile engine.

Figure 2 shows the detailed view of the conventional mounting bracket for catalytic converter in an automobile engine.

Figure 3 shows an enlarged view of arrangement of the mounting bracket fitted on the catalytic converter shell depicted in Figures 1, 2.

Figure 4 shows a stress contour plot for the mounting bracket for the catalytic converter depicted in Figure 2 and 3.

Figure 5 shows the mounting bracket for the catalytic converter configured in accordance with the present invention.
Figure 6 shows a stress contour plot for the mounting bracket shown in Fig. 4.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1 shows the catalytic converter 10 mounted by means of the conventional supporting bracket 20 connected to a silencer or muffler 30 via an exhaust gas pipe 40 by means of a coupling 50 for carrying the combusted gaseous mixture exhausted from an exhaust port 60 in automobile engine 70.

Figure 2 shows a typical configuration of the conventional mounting bracket 20 for fitting the catalytic converter 10 on an automobile engine. The mounting bracket 20 is disposed transverse to the shell 14 of the catalytic converter 10. The exhaust port 60 is depicted connected to the catalytic converter 10 via a pipe 16 on the inlet side thereof. The catalytic converter 10 is connected at the outlet side thereof to an exhaust pipe 40 via a coupling 50.

Figure 3 shows an enlarged view of the arrangement of the conventional mounting bracket 20 for fitting the catalytic converter 10 on an automobile engine. The mounting bracket 20 is disposed along an axis Y – Y disposed transverse to the axis X – X of the shell 14 of the catalytic converter 10. The inlet 12 to the catalytic converter 10 and the outlet 52 of the coupling 50 are also depicted in this figure. Here, very little area of the mounting bracket 20 is welded to the catalytic converter shell 14, which causes stress concentration in the limited available weld area 24.

Figure 4 shows a colored stress contour plot for the conventional mounting bracket shown in Figure 2. The highest stress values (approximately 127 MPa) are noticed in the regions 22 marked in red colour, which is in the vicinity of the welds between the catalytic converter shell 14 and mounting bracket 20.

Figure 5 shows the improved mounting bracket 120 for the catalytic converter 10 modified in accordance with the present invention. The mounting bracket 120 is disposed along an axis parallel to the axis X–X of shell 14 of catalytic converter 10, which is also parallel to the axis x – x of the mounting bolt. In contrast to Figure 3, here the mounting bracket 120 has wide flanges 124 and which offer a very large area of the mounting bracket 120 is welded to the catalytic converter shell 14, which substantially reduces the stress concentration in this increased weld area on the wide flanges 124 available on the shell 14.

Figure 6 shows a colored stress contour plot for the mounting bracket shown in Figure 5. The highest stress values noticed in the welded region 122 marked in green colour are substantially lower (approximately 27 kPa) than in the corresponding welded region 22 in the conventional mounting bracket 10 depicted in Figure 4.

WORKING OF THE INVENTION:

In the present invention, catalytic converter mounting bracket 120 is orientated parallel to the axis X – X of the catalytic converter (mounting bolt axis x - x is parallel to the catalytic converter axis X – X). With this, it is possible to suitably configure the layout of the catalytic converter bracket 120.

Therefore, there is a considerable improvement in Natural frequency and thermal stress. It also meets natural frequency requirement due to better stiffness in transverse direction.

It also induces lower thermal stresses due to reduction of stiffness in the direction of expansion (along the axis of the catalytic converter).

It also offers a substantially large welding area between the catalytic converter shell and wide flanges of the mounting bracket welded thereon, which results in an excellent load distribution on the catalytic converter shell.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The bracket for mounting catalytic converter for thermal compliance in expansion direction and stiffness in other directions configured in accordance with the present invention has the following advantages:

• Facilitates thermal compliance in the expansion direction.

• Fulfils natural frequency requirements in the transverse direction.

• Induces lower thermal stresses due to vibrations.

• Induces lower thermal stresses due to vibrations.

• Facilitates in an excellent load distribution on the catalytic converter shell.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps. In the claims and the description, the terms “containing” and “having” are used as linguistically neutral terminologies for the corresponding terms “comprising”.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention. Furthermore, the use of the term “one” shall not exclude the plurality of such features and components described.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention.
The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

In the previously detailed description, different features have been summarized for improving the conclusiveness of the representation in one or more examples. However, it should be understood that the above description is merely illustrative, but not limiting under any circumstances. It helps in covering all alternatives, modifications and equivalents of the different features and exemplary embodiments.

Many other examples are directly and immediately clear to the skilled person because of his/her professional knowledge in view of the above description. Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention.

These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

The exemplary embodiments were selected and described in order to be able to best represent the principles and their possible practical application underlying the invention. Thereby, the skilled persons can optimally modify and use the invention and its different exemplary embodiments with reference to the intended use. ,CLAIMS:We claim:

1. A bracket for mounting the catalytic converter on an automobile engine, wherein the bracket prevents stress concentration in the joint thereof with the catalytic converter shell.

2. Bracket as claimed in claim 1, wherein the bracket fulfils thermal compliance in the axial direction of the catalytic converter.

3. Bracket as claimed in claims 1 to 2, wherein the bracket fulfils the natural frequency requirements in terms of the stiffness in the transverse direction of the catalytic converter.

4. Bracket as claimed in claim 2, wherein the bracket orientation is in the direction of deformation of the catalytic converter.

5. Bracket as claimed in claim 3, wherein the bracket axis is parallel to the catalytic converter axis.

6. Bracket as claimed in anyone of the claims 1 to 5, wherein the bracket comprises wide flanges providing large area for substantially improved load distribution on the shell of the catalytic converter.

7. Bracket as claimed in anyone of the claims 1 to 6, wherein the bracket body is configured in ‘C’ section with outwardly extended flanges to be joined on the catalytic converter shell.

8. Bracket as claimed in anyone of the claims 1 to 7, wherein the bracket mounting bolt axis is parallel to the catalytic converter axis.

9. Bracket as claimed in anyone of the claims 1 to 8, wherein the bracket is joined to the catalytic converter shell by means of welded joints.

10. Bracket as claimed in anyone of the claims 1 to 9, wherein the stress concentration in the bracket joint to the catalytic converter shell is reduced by approximately 50 to 75% in comparison to the bracket having its axis disposed perpendicular to the catalytic converter axis.

11. Bracket as claimed in anyone of the claims 1 to 10, wherein the value of Von Mises Maximum stress in the vicinity of the joint of the bracket to the catalytic converter shell is in a range of 20 to 30 MPa.