EP1586753A2

EP1586753A2 - Fastening system of an exhaust group to a scooter

Info

Publication number: EP1586753A2
Application number: EP05102728A
Authority: EP
Inventors: Francesco Caratelli
Original assignee: Piaggio and C SpA
Current assignee: Piaggio and C SpA
Priority date: 2004-04-14
Filing date: 2005-04-07
Publication date: 2005-10-19
Also published as: TW200537013A; EP1586753A3; ITMI20040736A1; CN1683204A

Abstract

Fastening system of an exhaust group, of the type equipped with at least one muffler (2) and at least one manifold pipe (3, 4, 3'), to a scooter (10). The fastening system has at least one flexible coupling (5), arranged between the muffler (2) and the exhaust hole (6) of the engine (7), and attachment means (8) suitable for connecting the muffler to the frame (9) of the scooter (10).

Description

The present invention concerns a fastening system of an exhaust group to a scooter.
In the field of two-wheeled vehicles known as scoters, the engine is typically an integral part of the rear fork that in such a way makes the rear suspension.
According to the aforementioned solution the engine is "hinged" to the frame and oscillates with respect to it about a centre of rotation.
In this type of embodiment, the muffler is therefore installed integrally to the engine, fixing the manifold of the muffler to the exhaust hole present on the engine, whereas the end part thereof is fixed to the engine by means of a rear suspension element. Such a suspension element is, in general, also used for the attachment of the shock absorber.
In this way, the muffler, like the engine, also has an oscillating movement with respect to the frame and, consequently, the entire exhaust system increases the so-called "non-suspended mass" of the vehicle.
In other words, this is the mass of the components of the vehicle integral with the wheels.
Therefore, a distribution of the masses is created that is particularly disadvantageous from the point of view of rider comfort, meaning the degree of transmission to the rider, through the interface points (handlebars, foot rest, seat), of the vibrations originating from the unevenness of the road surface.
In some cases, rider comfort can even reach critical levels also from the point of view of safety.
In light of the above, there is clearly a need to be able to have a fastening system of an exhaust group to a scooter that ensures that most of the mass linked to the exhaust system, integral with the oscillating engine, is transformed into suspended mass improving rider comfort.
Therefore, the purpose of the present invention is that of solving the problems of the prior art by providing a fastening system of an exhaust group to a scooter that allows the non-suspended masses to be reduced and allows the suspended masses of the vehicle to be increased, at the same time improving rider comfort.
Another purpose of the present invention is that of providing a fastening system of an exhaust group to a scooter that allows the transmission of the vibrations generated by the unevenness of the road surface in the interface points between vehicle and rider to be decreased.
Another purpose of the present invention is that of providing a reliable and safe fastening system of an exhaust group to a scooter that is, at the same time, easy and cost-effective to produce.
These and other purposes are accomplished by the fastening system of an exhaust group to a scooter according to the present invention that has the characteristics of the attached claim 1.
Substantially, a fastening system of an exhaust group, comprising at least one muffler and at least one manifold pipe to a scooter according to the present invention is characterised in that it comprises at least one flexible coupling, arranged between the muffler and the exhaust hole of the engine, and attachment means suitable for connecting the muffler to the frame of the scooter.
Further characteristics and advantages of the present invention shall become clearer from the following description, given for illustrative and not limiting purposes, with reference to the attached drawings, in which:

figure 1 shows a side view of the rear of a scooter equipped with the fastening system of the exhaust group according to the present invention;
figure 2 shows an enlarged partial perspective view of a detail of the fastening system of an exhaust group to a scooter according to the present invention;
figure 3 shows an enlarged view of the attachment means of the muffler to the frame of a scooter according to the present invention; and
figure 4 shows a side view of the rear of a scooter equipped with a second embodiment of the fastening system of the exhaust group according to the present invention;

With reference to the figures, a fastening system of an exhaust group, equipped with at least one muffler 2 and with at least one manifold pipe 3', 3, 4, to a scooter 10 is shown.
The fastening system, according to a preferred embodiment, shown in figures 1 to 3, has a flexible coupling 5, arranged between the muffler 2 and the exhaust hole 6 of the engine 7, and suitable attachment means 8 suitable for connecting the muffler 2 to the frame 9 of the scooter.
In detail, the attachment means 8 are arranged to fasten the muffler 2, near to its rear portion, to the end portion of the frame 9.
Advantageously, according to the present embodiment, the attachment means 8 are represented by a first bracket 14, integral with the muffler 2, by a second bracket 15, integral with the frame 9, and by a support arm 16, hinged to both of the brackets 14, 15.
In detail, the support arm 16 is hinged, through known means such as screws and bolts, at one end to the first bracket 14 and at the other end to the second bracket 15.
Alternatively, the support arm 16 could be integral with the frame 9, in other words made as a projecting portion of the frame itself, and hinged at the free end to a bracket integral with the muffler 2.
In a further embodiment, the suspension arm 16 can be integral with the muffler 2 and be hinged to a bracket integral with the frame 9.
Returning to the preferred embodiment, shown in figures 1-3, it is revealed that the flexible coupling 5 is connected and arranged between a first 3 and second 4 manifold pipe.
In detail, the first manifold pipe 3 connects the coupling 5 to the exhaust hole 6 of the engine 7, whereas the second manifold pipe 4 connects the coupling 5 to the muffler 2.
On the second manifold pipe 4, as shown in figure 1, there is a flanged portion 17 suitable for coupling, through known means such as screws and bolts, with a corresponding flanged portion 18 of the muffler 2.
According to the present invention, the flexible coupling 5 is positioned near to the centre of rotation 11 of the engine 7 with respect to the frame 9 so as to reduce possible ripping away on the coupling itself, whilst the scooter 10 moves.
A flexible coupling particularly suitable for the purpose is described in patent EP0083910 to Tubiflex S.p.A.
To protect the flexible coupling from dangerous relative torsions between the manifold pipes 4 and 5, protective elements 12, 13 are foreseen, at least one of which is hinged on the centre of rotation 11 of the engine 7 with respect to the frame 9.
The two protective elements 12, 13 partially wrap around the flexible coupling 5 and the end portions of the manifold pipes 3 and 4 and are shaped to protect the coupling, as well as from torsions, also from relative axial and lateral movements of the manifold pipes 3 and 4.
In figure 4 an alternative embodiment of the present invention is shown that is totally similar to the one illustrated in figures 1 to 3 apart from the fact that it has just one manifold pipe 3' and attachment means 8 of the muffler 2 to the alternative frame 9.
In detail, the manifold pipe 3' is connected at one end to the exhaust hole 6 of the engine 7 and at the other end to the flexible coupling 5.
The flexible coupling 5, as shown in figure 4, is directly connected to the muffler 2.
Also according to this embodiment, the flexible coupling 5 is positioned at the centre of rotation 11 of the engine 7 with respect to the frame.
The attachment means 8, as shown in figure 4 according to the present embodiment, comprise a first bracket 14', integral with the muffler 2, hinged directly to the frame 9 of the scooter 10.
The fastening system of the exhaust group to the scooter according to the present invention allows the mass of the exhaust group to be transformed from non-suspended mass into suspended mass, improving rider comfort.
In other words, the mass of the exhaust group is no longer, like in conventional scooters, integral with the engine and with its oscillations with respect to the frame, but is separate from it and from its oscillating movements, so as to be suspended at the frame.
In such a way, the transmission of vibrations originating from the unevenness of the road surface in the interface points between scooter and rider is reduced, increasing rider comfort.
The present invention has been described for illustrating, but not limiting purposes, according to its preferred embodiments, but it should be understood that variations and/or modifications can be brought by men skilled in the art without for this reason departing from the relative scope of protection, as defined by the attached claims.

Claims

Fastening system of an exhaust group, comprising at least one muffler (2) and at least one manifold pipe (3, 4), to a scooter (10) characterised in that it comprises at least one flexible coupling (5), arranged between said muffler (2) and the exhaust hole (6) of the engine (7), and attachment means (8) suitable for connecting said muffler (2) to the frame (9) of the scooter (10).
Fastening system of an exhaust group according to claim 1, characterised in that said flexible coupling (5) is positioned near to the centre of rotation (11) of the engine with respect to the frame (9) of the scooter (10).
Fastening system of an exhaust group according to any one of the previous claims, characterised in that it comprises at least one protective element (12, 13), hinged to said frame (9) at said centre of rotation (11) of the engine, suitable for protecting said flexible coupling (5) and for avoiding dangerous movements of said flexible coupling (5).
Fastening system of an exhaust group according to any one of the previous claims, characterised in that it comprises a first manifold pipe (3) connected to said exhaust hole (6) of the engine (7) and to said flexible coupling (5) and a second manifold pipe (4) connected to said flexible coupling (5) and to said muffler (2).
Fastening system of an exhaust group according to any one of claims 1 to 3, characterised in that it comprises a single manifold pipe (3') connected at one end to said exhaust hole (6) of the engine and at the other end to said flexible coupling (5) in turn directly connected to said muffler (2).
Fastening system of an exhaust group according to any one of the previous claims, characterised in that said attachment means (8) comprise a first bracket (14) integral with said muffler (2), a second bracket (15) integral with the frame (9) of the scooter and a connection arm (16) hinged at one end to said first bracket (14) and at the other end to said second bracket (15).
Fastening system of an exhaust group according to any one of the previous claims from 1 to 5, characterised in that said attachment means (8) comprise a first bracket (14') integral with said muffler (2), hinged directly to said frame (9) of the scooter.
Scooter characterised in that it comprises a fastening system of an exhaust group to the scooter according to any one of the previous claims.