IMPROVED SILENCER WITH UNWELDED CONNECTION OF THE CAPS AND THE PIPES

Abstract: As improved silencer for internal combustion engines with unwelded connection of the caps and the pipes is provided, wherein its inner pipe (4) is fixed by seaming to the end caps (3) of the silencer, while the incoming exhaust pipe and or the outgoing tail pipe are in turn fixed by seaming to the corresponding ends of said inner pine (4), with reduction of costs, better quality of the silencer and improvement of the environmental working conditions.

Description: "Improved silencer with unwelded connection of the caps and the pipes" The present invention relates to a silencer having a considerable utility and ease of use because of the unwelded connection of the caps and the pipes to the ends of said silencer. The silencers presently available on the market have the considerable drawback of requiring weldings for joining the various components and it is known that welding is a time-consuming, troublesome, expensive and polluting process, requiring also skilled and qualified operators. The quality of the weld affects in a decisive way the performance and operative life of the silencer, and in view of the steadily increasing shortage of skilled qualified welders, it is more and more difficult to produce silencers of a good quality and long-lasting. Furthermore, welding has the intrinsic drawback of altering the material of the workpiece and of its coating (aluminizing) so that it is necessary to carry out again plating of the metal at the welding area after the welding operation. The present invention removes these drawbacks because it eliminates welding of the silencer inner pipe to the end caps as well as of the exhaust and tail pipes to the inner pipe, which is now forming a mass of weld material all around and on the edge of the cap bore. The improved silencer according to the present invention is therefore characterized by the fact that its inner pipe is fixed to the end caps by seaming, while the incoming exhaust pipe (from the engine) and the outgoing tail pipe are in turn fixed to the corresponding ends of the inner pipe also by seaming. The advantages obtained with this system are various and considerable, such as the great reduction of manufacturing cost due to welding elimination, without needing the specialized staff for it, which can now be replaced by unskilled labor, moreover doing a light job in a non polluting environment; manufacturing speed and uniform qualify o the product, no more subject to the individual skill of the welders; elimination of thermal stresses and chemico-physical alterations of the material, which were caused by the welding process. These and other advantages, objects and features of the present invention will be more apparent from the following detailed description, made with reference to the sole figure of the accompanying drawing, diagramatically showing the area of connection of the inner pipe to an end cap of the silencer, as well as of an exhaust pipe to the end of said inner pipe. With reference now to said sole figure of the accompanying drawing, one can see partially the outer body 1 of the silencer to which the usual closure cap 3 is seamed by means of a double heading 2. The silencer inner pipe 4 is fixed to the cap 3 by seaming, obtained by cold making with a suitable tool two waves or dimples 5 and 6 between which the edge 7 of the cap bore is clamped, so as to create the stable, safe and resistant connection of said elements, by means of pressure and deformation of the two matching surfaces. In the same way the exhaust line is fixed at the end of inner pipe 4, protruding outside the silencer. The pipe 8, which can be either the incoming exhaust pipe from the engine exhaust manifold or the outgoing tail pipe discharging to the atmosphere the exhaust gases, is inserted into or onto the end of said inner pipe 4 and then with an outer seaming operation for the two assembled pipes, two corresponding waves or dimples 9 and 10 are formed on them, so as to mutually clamp them in a stable and safe way. It is to be understood that the materials used, the equipment and tools used to carry out the connection of the elements, the number and size of the pipes may be varied in the wider and greater manner, without departing however from the principles and the features illustrated and described hereinbefore.

Claims: CLAIMS 1) Improved silencer, characterized by the fact that its inner pipe (4) is fixed by seaming to the end caps (3) of the silencer, while the incoming exhaust pipe and/or the outgoing tail pipe are in turn fixed by seaming to the corresponding ends of said inner pipe (4). 2) Improved silencer according to Claim 1, characterized by the fact that the inner pipe (4) gets by cold deformation two waves or dimples (5, 6) between which the edge (7) of the silencer cap bore is clamped. 3) Improved silencer according to Claim 1, characterized by the fact that tne incoming exhaust pipe and/or the outgoing tail pipe is inserted into or onto the free end of the silencer inner pipe (4) and then the two assembled pipes get by cold deformation two corresponding waves or dimples (9, 10) which are mutually clamping them together. 4) Improved silencer according to one or more of the preceding claims, characterized by the fact that the end cap (3) is seamed to the silencer body (1) by double heading (2).

Inventors: MARZORATI, ATTILIO, SALA, ALFREDO
Applicants: S.I.E.T.T.E.  SOCIETA IMPIANTI ELETTRICI TELEFONICI TELEGRAFICI & COSTRUZIONI EDILI SPA
Application year: 1982
Main classification: F01N7
IPC codes: F01N13