Motorcycle and motorcycle rear wheel swingarm with integrated resonator

Abstract

A motorcycle has an engine and an exhaust gas pipe which is connected thereto, as well as a motorcycle rear wheel swingarm. The motorcycle rear wheel swingarm has a closed cavity which is in fluid connection with the exhaust gas pipe by way of a connecting element.

Claims

1. A motorcycle, comprising: an engine; an exhaust pipe coupled with the engine; a rear wheel swingarm, wherein the rear wheel swingarm comprises an enclosed cavity in fluid communication with the exhaust pipe via a connecting element branching away from the exhaust pipe, the cavity being configured as a Helmholtz resonator with no aperture other than at a location where the connecting element communicates with the cavity.

2. The motorcycle according to claim 1, wherein the rear wheel swingarm has a hollow-chamber profile.

3. The motorcycle according to claim 1, wherein the connecting element is a temperature-resistant hose.

4. The motorcycle according to claim 1, wherein the connecting element is fixed to the cavity and the exhaust pipe via respective connection fittings.

5. The motorcycle according to claim 1, wherein the connecting element is connected to the exhaust pipe upstream of a rear muffler and downstream of a catalytic converter when viewed in an exhaust gas flow direction.

6. The motorcycle according to claim 1, wherein the cavity has a volume of 1,000-3,000 cm.sup.3.

7. The motorcycle according to claim 6, wherein the connecting element has a length of 120-250 mm.

8. The motorcycle according to claim 1, wherein the connecting element has a length of 120-250 mm.

9. The motorcycle according to claim 7, wherein the connecting element has a diameter of 30-40 mm.

10. The motorcycle according to claim 1, wherein the connecting element has a diameter of 30-40 mm.

11. A motorcycle component, comprising: a rear wheel swingarm, wherein the rear wheel swingarm comprises an integrated cavity configured as a Helmholtz resonator, and the cavity being configured for a fluid communication with a branch from an exhaust pipe, and having no aperture other than at a location where the cavity communicates with the exhaust pipe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a motorcycle rear wheel swingarm;

(2) FIG. 2 is a side view of the motorcycle rear wheel swingarm according to FIG. 1, partially cut away; and

(3) FIG. 3 is a front view of the motorcycle rear wheel swingarm in FIG. 1, partially cut away.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) The figures are diagrammatic examples. The same reference numerals denote the same parts in all views.

(5) FIG. 1 represents a perspective view of a motorcycle rear wheel swingarm (rear wheel fork) 1 formed as a hollow-chamber profile with an exhaust pipe 2 extending at a lateral distance therefrom. Only a short portion of the exhaust pipe 2 is represented; the further extent to the rear muffler and to the engine is omitted for reasons of clarity. A temperature-resistant hose 4 extends from the exhaust pipe 2 to the motorcycle rear wheel swingarm and provides a flow connection between the exhaust pipe 2 and a cavity 3 of the motorcycle rear wheel swingarm 1, so that a standing column of air or column of exhaust gas in the connecting element can oscillate together with the quantity of air in the cavity 3 as a function of the engine speed and load.

(6) FIG. 2 shows a side view of the motorcycle rear wheel swingarm 1 in FIG. 1, the area comprising the enclosed cavity 3 being represented partially cut away. At the bottom the hose 4 is fixed to the motorcycle rear wheel swingarm 1 immediately adjacent to the swingarm center of rotation 7, since here the the relative movement is slight. The cavity 3 is formed as a Helmholtz resonator, the enclosed cavity 3 of which is substantially box-shaped. Alternatively, it would also be possible for this to be formed as a rectangular solid or with a rounded and also, in particular, circular shape. The volume shown is approximately 2500 cm.sup.3, but this may be modified according to the arrangement of the exhaust system and as a function of the desired frequency spectrum. The same applies to the dimensioning of the hose 4, the length and diameter of which have a direct influence on the effect of the cavity 3. In the embodiment, the hose is approximately 160 mm long and 32 mm in diameter.

(7) FIG. 3 represents a front view of the embodiment in FIG. 2, the connection of the hose 4 to the cavity 3 being shown cut away. FIG. 3 shows the connection fitting 5, which is formed on the motorcycle rear wheel swingarm 1 in the area of the cavity 3 and onto which the hose 4 is pushed and secured by means of a clamping band 6. A corresponding attachment is also provided on the exhaust pipe 2.

(8) The invention is not limited to the preferred exemplary embodiments described above, but rather encompasses variants which also make use of the solution represented in embodiments of fundamentally different type. For example, the connecting element may also be attached laterally to the swingarm.

(9) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.