AU2009100344A4

AU2009100344A4 - Silencer and components therefor

Info

Publication number: AU2009100344A4
Application number: AU2009100344A
Authority: AU
Inventors: Jing Yu Liang
Original assignee: UNIVERSAL AUTO ACCESSORIES UAA
Current assignee: UNIVERSAL AUTO ACCESSORIES (UAA) Pty Ltd
Priority date: 2008-04-16
Filing date: 2009-04-16
Publication date: 2009-06-04
Anticipated expiration: 2017-04-16

Description

Our Ref: 20535123 P/00/01I Regulation 3:2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Applicant(s): Universal Auto Accessories (UAA) Pty Ltd 236A Burwood Road, Burwood, New South Wales 2134, Australia Address for Service: DAVIES COLLISON CAVE Patent & Trade Mark Attorneys 255 Elizabeth Street SYDNEY NSW 2000 Invention Title: "Silencer and components therefor" The following statement is a full description of this invention, including the best method of performing it known to me:- SILENCER AND COMPONENTS THEREFOR 5 Field of the Invention The present invention relates generally to mufflers or silencers, and in one particular application, to those silencers suitable for use with internal combustion engines on motor vehicles. 10 Background of the Invention It is known to connect the parts of a silencer together by firstly forming an outer shell, then hand welding pipes to supporting plates and forcing the plates with attached 15 pipes into the pre-made shell. However, the welding process negatively affects the grain structure and stability of the parts and tends to reduce the life of the silencer. This is because the silencer is always installed in an aggressive environment, where there are extremes of heat and cold, coupled 20 with extremes of moisture, dryness, high vibration, and large amounts of corrosive gases at high pressure. Since the weld points are susceptible to rusting, the silencer itself is prone to failure. Once a silencer is rusted internally, repair is not a practical option and the silencer 25 needs to be replaced in its entirety. Further, there may be a number of silencers discarded as rejects during the manufacturing phase as a result of the above construction method if the pipes and plates are forced out of shape when being forceably inserted into the shell of the silencer, 30 Object of the Invention The present invention seeks to provide an alternative construction method and silencer construction. 35 P:\WPDOCS\HSi2009\DH\Specirications2o342593 Uaiveral Auto Prov doa - 8//09 -2 Summary of the Invention In accordance with the present invention, there is provided a silencer formed of an outer shell, and internal plate, and a tube which passes through the plate, the tube having a 5 joint region which is received in a socket of the plate wherein the joint region has as enlarged portion which is plastically deformed with the socket into a non-circular profile. Preferably, the profile of the enlarged portion includes lobes which are most preferably arranged in a square-shaped configuration. 10 Preferably, the silencer includes a second internal plate and multiple tubes, each of the tubes having associated enlarged portions to couple the tubes to each of the respective first and second plates. 15 In another aspect, there is provided a method of forming a silencer including coupling a tube to an internal plate of the silencer by deforming a joint region of the tube to form an enlarged portion which is plastically deformed into a socket of the plate such that the tube, and the socket adjacent the joint portion, has a non-circular profile. 20 Preferably, the method includes providing a second plate and fixing a plurality of tubes in the first and second plates of the silencer by deforming respective joint regions of the tubes to engage with associated sockets of the plates in order to provide the tubes with non-circular profiles at the joint regions and securely locate the tubes relative to the plates. 25 In another aspect, there is provided a tool for expanding a tube to fit with a socket of an internal plate of a silencer, including a die head, an expander and a drive mechanism to drive the expander longitudinally of the tool, to effect expansion and contraction of the die head, wherein the die head is non-circular. 30 Preferably, the die head includes four corner pieces adapted to move radially to produce lobes in the tube, in a square-shaped configuration.

P kWPDOC5MuCDMSpissia-2032593 UMaml A.io P. dectO.4/2009 -3 According to another aspect of the present invention there is provided a silencer suitable for use in silencing exhaust gases from an internal combustion engine, the silencer including a housing; a plate mounted in the housing so as to divide the housing into one or 5 more chambers; at least one tube having a longitudinal axis and extending, when assembled, from one side of the plate to the other; the at least one tube including an enlarged portion disposed at a joint region, wherein the tube is disposed at least partially through the plate so that the enlarged portion is in cooperative engagement with a socket region associated with the plate so as to couple the tube to the plate and inhibit rotational 10 movement of the tube about the longitudinal axis. According to another aspect of the present invention there is provided a tube for use with a silencer, the tube having a longitudinal axis and extending when assembled, from one side of a plate of the silencer to the other; the at least one tube including a joint 15 region, wherein the tube is configured so that when assembled an enlarged portion thereof is in cooperative engagement with a socket region associated with the plate so as to inhibit rotational movement of the tube about the longitudinal axis. According to yet another aspect of the present invention there is provided a method 20 of assembling a silencer, the method including the steps of; providing a tube having a longitudinal axis; providing a baffle plate for receiving the tube; sliding the tube through the plate; forming a joint which includes a socket associated with the plate and a corresponding enlarged portion in the tube so as to inhibit rotational movement of the tube about the longitudinal axis. 25 Preferably the portion and the socket are non-circular in cross-section so that when the enlarged head portion is cooperatively engaged with the socket, rotational movement about the longitudinal axis is inhibited by corners or lobes or vertices of the non-circular cross-section. Although the enlarged head portion and the socket may be any suitable non 30 circular cross-section, it is preferred that the head portion be a square section.

-4 Preferably the enlarged head portion includes one or more stops, which are each preferably in the form of a bulb so as to inhibit axial movement of the tube. The tube may include a detent, which is preferably in the form of two stops, each one spaced apart from the other. Some arrangements include a tube adapted for snap engagement of the joint 5 region of the tube into the socket region of the plate. The plate may include a support which may be in the form of a flange so that the socket may support the tube along at least a portion of its length. Preferably the plate includes a keeper to inhibit release of the tube from the joint region in the axial direction. 10 Preferably the keeper is the flange which extends perpendicular to the plate and is adapted to be turned or rolled back along its height. The flange may be tapered slightly inwardly so as to facilitate keeping. The plate preferably is disposed transverse to the silencer housing. 15 Preferably the tube includes a first end and a second end, the first end being disposed when assembled in a first chamber and the second end when assembled being disposed within a second chamber. The first end includes perforations so that exhaust or other gases may enter or exit the first chamber. 20 There may be provided a secondary penetration through the plate. This may be in the form of a secondary tube. The secondary tube is preferably smaller in diameter than the first tube and includes a first end which when installed in the plate, extends therethrough so as to form a keeper in the form of a flange which in use is rolled or turned 25 along the secondary tube's longitudinal axis. Brief Description of the Drawings The invention will now be described, by way of non-limiting example only, with 30 reference to the drawings, in which: -5 Figure 1 is an isometric cutaway view of a silencer; Figure 2 is a first end view of the silencer of Figure 1; 5 Figure 3 is a second end view of the silencer of Figure 1; Figure 4 is one side view of the silencer of Figure 1; Figure 5 is another side view of the silencer of Figure 1; 10 Figure 6a is a diagrammatic side view of a tool used in the manufacture of the silencer in a contracted condition; Figure 6b is an end view of the tool; 15 Figure 7a is a diagrammatic side view of the tool in an expanded condition; Figure 7b is an end view of the tool in an expanded condition; and 20 Figure 8 is a perspective sectioned view of another silencer. Detailed Description of the Invention Referring to Figures 1 to 5 of the drawings there is shown a silencer or muffler 25 generally indicated at 10. The silencer 10 is suitable for reducing the noise level of exhaust gases from an internal combustion engine (not shown). The silencer 10 includes an outer shell or housing 12 formed of a sheet of steel 13 having ends which when the silencer is assembled are connected together at seam 14. The silencer includes end plates (not shown) through which an exhaust inlet and an exhaust outlet penetrate when mounted 30 in an exhaust system. The end plates close first and second chambers 16 and 18. A plate 19 extends across internal walls of the housing 12 between the first and second chambers AWPDOCS\H5 Huptfion'2;342Af Uniersal Aum Pr-h M /209 -6 16 and 18 to define an internal wall of each chamber. The first and second chambers are caused to be in fluid communication by penetrations 20 and 21 through the plate 19. A first tube 22 extends through penetration 5 20, and a second tube 24 extends from one side of the penetration 21 when assembled. The first tube 22 includes a first end portion 26 and a second end portion 27. The first end portion 26 is disposed in the first chamber 16 when assembled in the silencer housing 12 and includes perforations 28 through the tube wall so that exhaust or other 10 gases may pass therethrough, into or from the second chamber 18. The first tube 22 is circular in cross section in the first and second portions, however, in a joint region 30, when assembled, the first tube includes an enlarged portion 32 which cooperatively engages with a socket 34 disposed in plate 19. The enlarged 15 portion 32 has a non-circular cross-section 33, being square 35 with rounded lobes or vertices 36 to reduce stress concentrations. The walls of the square 35 correspond with, and in use abut the walls of the socket 34, The latter of which includes a support 37 in the form of a flange 38 extending from the plate 19 so as to support the tube 22 along a portion of its length, 20 The tube 22, when assembled, also includes a stop 40 in the form of a bulb 41 so that axial movement of the tube relative to the plate 19 in one direction is inhibited. A keeper 42 is also provided so as to inhibit axial movement in the other direction. The keeper 42 is in the form of the flange 38 which may during assembly have one end pushed 25 into the tube or turned back along its height so as to press against the wall of the tube 22. The second tube 24 extends a short distance through the plate 19 so that a first end 25 extends therethrough. To keep the tube in place, the first end 25 is turned or rolled down so that the tube is inhibited from axial movement relative to the plate 19. 30 To assemble, firstly, the plate 19 has a circular flange 38 formed into it around the -7 penetration 20. The tube 22, which at this first stage is a cylinder along its entire length, is slid through the penetration 20 in the plate 19 from one side. The plate 19 and tube 22 are pushed together at the area of the penetration 20 and flange 38 so that a socket 34 is formed in the plate 19. Alternatively, the socket 34 is pre-formed and the tube 22 slid 5 through a socket 34 to a pre-determined position where the enlarged portion 32 is formed by plastic deformation of the tube 22 in the joint region 30, The square walls of the portion 32 inhibit rotation of the pipe about its longitudinal axis. The flange 38 is deformed together with the wall of the tube 22 so as to provide a mechanical lock and inhibit axial movement of the tube through the socket 34, and to further inhibit rotation. 10 In order to deform the tube 22 at the appropriate location and to the desired shape, an elongate expansion tool 50, as shown in Figures 6 and 7, is used. The tool 50 has a die head 51 which co-operates with an expander 52, which is in turn mounted on a shaft 53, and arranged for screw threaded adjustment along the shaft 53, for variably axial 15 positioning, dependent upon the location at which expansion is required, The shaft 52 is coupled through a base 54 of the tool 50, to a piston 55 which is actuated via a drive mechanism 56. The drive mechanism 56 includes an hydraulic pump with connecting conduits 57, 20 58 to control pressure applied to the piston 55, in order to drive the piston 55 longitudinally of the tool 50. In the arrangement shown in Figure 6, the die head is in a contracted condition, under compressive action of spring 59, where corner sections 60 of the die head are closed 25 together. In that condition, the tool 50 can be fed inside the tube 22 to a position where the die head 51 is adjacent a location where the enlarged portion 32 needs to be formed. Once in position, the drive mechanism 56 is activated to draw the piston 55 through the base 54, which results in the expander 52 engaging the die head 51 and forcing the 30 sections 60 against the bias of spring 59 in a radial outwardly direction, to assume the expanded condition shown in Figure 7. In that condition, the corner sections 60 are -8 effective in plastically deforming the tube 22 so as to form lobes in a generally square configuration, corresponding to the positioning of the corner sections 60. The surrounding socket 34 is also deformed with the enlarged portion 32 so as to mechanically lock the tube 22 to the plate 19, to prevent both axial and rotational movement. 5 In order to withdraw the tool 50, operation of the drive mechanism 56 is simply reversed to allow the die head 51 to move back into the collapsed condition, where the tool 50 can be removed completely or transferred to another position within the tube 22 for another expansion operation, such as where two enlarged portions 32 are required along 10 the length of the tube 22. Figure 8 shows a second silencer 70 which has similar components to the silencer 10 and like parts are referred to with like reference numerals. The silencer 70 is constructed using the same general principles as the silencer 10, except that two plates 19 15 and three tubes 22 are provided. Each tube 22 is fixed in an associated socket 34 using an expansion tool to form enlarged portions 32 at two locations corresponding to the plates 19, so as to plastically deform both the tubes 22 and the sockets 34 into a non-circular profile. 20 Compared to the prior manufacturing method, a silencer 10, 70 of the present invention may be produced comparatively more easily. Once the shell or housing is formed and the plate(s) 19 fixed in place, the pipes are secured by simply sliding the pipes through the socket(s) 34 and inserting an expansion tool 50 into the pipe(s) 22 to expand the pipe(s) 22 to form the enlarged portion(s) 32, to thereby fix the pipe(s) 22 in place, 25 without the need for welding. Since welding of the pipes is not required and there is also no longer any need to weld the pipes to the plates before inserting them in the shell of the silencer, the present invention can provide comparative advantages by reducing the number of reject silencers, 30 reducing manual labour and increasing the life time of the silencer.

-9 The invention has been described specifically with reference to silencers, however, the term silencer is intended to also include within its scope any other form of muffler or the like 5 The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 10 Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or 15 steps. Finally, it is to be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that the generality of the preceding description is not to be superseded by the particularity of the attached drawings. Various 20 alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or anbit of the invention,

Claims

1. A silencer formed of an outer shell, and internal plate, and a tube which passes 5 through the plate, the tube having a joint region which is received in a socket of the plate wherein the joint region has as enlarged portion which is plastically deformed with the socket into a non-circular profile,

2. The silencer of claim 1, wherein the profile of the enlarged portion includes lobes 10 which are most preferably arranged in a square-shaped configuration.

3. The silencer of claim 1 or 2, wherein the silencer includes a second internal plate and multiple tubes, each of the tubes having associated enlarged portions to couple the tubes to each of the respective first and second plates, 15

4. A method of forming a silencer including coupling a tube to an internal plate of the silencer by deforming a joint region of the tube to form an enlarged portion which is plastically deformed into a socket of the plate such that the tube, and the socket adjacent the joint portion, has a non-circular profile. 20

5. The method of claim 4, wherein the method includes providing a second plate and fixing a plurality of tubes in the first and second plates of the silencer by corresponding respective joint regions of the tubes to engage with associated sockets of the plates in order to provide the tubes with non-circular profiles at the joint regions and securely locate the 25 tubes relative to the plates.

6. A tool for expanding a tube to fit with a socket of an internal plate of a silencer, including a die head, an expander and a drive mechanism to drive the expander longitudinally of the tool, to effect expansion and contraction of the die head, wherein the 30 die head is non-circular.

7. The tool of claim 6, wherein the die head includes four corner pieces adapted to P \WDOCS HS2009NDHrtpec~r.iirAs20342593 mN;-a A w P-N.do. 4/209 - 11 move radially to produce lobes in the tube, in a square-shaped configuration.

8. A silencer, substantially as described with reference to the accompanying figures. 5

9. A method of forming a silencer, substantially as hereinbefore described with reference to the accompanying figures.

10. A tool, substantially as hereinbefore described with reference to the accompanying figures.