Search

CN-114687844-B - Automobile provided with exhaust system with pneumatic effect

CN114687844BCN 114687844 BCN114687844 BCN 114687844BCN-114687844-B

Abstract

The invention relates to a motor vehicle provided with an exhaust system having a pneumatic effect, comprising two front wheels (2), two rear wheels (3), a bottom wall which delimits a lower surface facing the road surface and which is blown by an air flow flowing under the motor vehicle (1) in use, an internal combustion engine (4), and an exhaust system (6) which is coupled to the internal combustion engine (4) and is provided with an exhaust pipe (7), the exhaust pipe (7) starting from the internal combustion engine (4) and having an end chamber (9) with an outlet opening (10) at the end through which outlet opening (10) exhaust gases are released into the atmosphere. The end chamber (9) of the exhaust pipe (7) has at least one movable partition (23) which can be moved to different positions to vary the width of the outlet opening (10). The movable partition (23) defines a lower surface of the end chamber (9) facing the road surface and being blown in use by an air flow flowing under the vehicle (1).

Inventors

  • Marco balatore
  • Matteo Osili
  • Simone Garuzzi
  • Emmanuelle Mariano

Assignees

  • 法拉利股份有限公司

Dates

Publication Date
20260505
Application Date
20211229
Priority Date
20201230

Claims (11)

  1. 1. An automobile (1), comprising: Two front wheels (2); two rear wheels (3); a bottom wall defining a lower surface facing the road surface and being blown, in use, by an air flow flowing under the vehicle (1); Internal combustion engine (4) An exhaust system (6) coupled to the internal combustion engine (4) and comprising an exhaust pipe (7), the exhaust pipe (7) starting from the internal combustion engine (4) and comprising an end chamber (9) having an outlet opening (10) at a distal end through which outlet opening (10) exhaust gases are released into the atmosphere, Wherein the end chamber (9) of the exhaust pipe (7) has at least one movable partition (23) which can be moved to different positions to vary the width of the outlet opening (10), Characterized in that said movable partition (23) defines a lower surface of said end chamber (9) facing the road surface and being blown in use by an air flow flowing under said vehicle (1), so as to increase the width of the extractor channel defined between the road surface and the lower movable partition (23) by moving the lower movable partition (23) away from the road surface, so as to increase the aerodynamic load generated by the extractor channel; the motor vehicle is further provided with a motor-driven actuating device (24) which is configured to actively move the movable barrier (23) and can be controlled electronically, and The vehicle is further provided with a control unit (27) configured to change the position of the movable barrier (23) by controlling the actuating means (24) and configured to move the movable barrier (23) away from the road surface when a large pneumatic load is required.
  2. 2. The vehicle (1) according to claim 1, characterized in that the end chamber (9) comprises a first fixed wall (28) ending in the region of the extremity of the movable partition (23) and defining a lower surface of the end chamber (9) facing the road surface and blown in use by an air flow flowing under the vehicle (1).
  3. 3. The vehicle (1) according to claim 2, characterized in that the first stationary wall (28) increases gradually with distance from the road surface towards the outlet opening (10).
  4. 4. The vehicle (1) according to claim 2, characterized in that the end chamber (9) comprises a second fixed wall (20) ending in the region of the end of the movable partition (23), being arranged higher than the first fixed wall (28) and delimiting at the bottom a space for the flow of exhaust gases.
  5. 5. The vehicle (1) according to claim 1, characterized in that the end chamber (9) is arranged behind the corresponding rear wheel (3).
  6. 6. The vehicle (1) according to claim 1, characterized in that the exhaust system (6) comprises: -a silencing device (11) opening into said end chamber (9); A bypass pipe (12) which starts from the exhaust pipe (7) and ends at the inlet of the silencer (11) in the region of the bifurcation (13), and -A regulating valve (14) which can be controlled electronically, is arranged along the exhaust pipe (7) downstream of the bifurcation (13) at the beginning of the bypass pipe (12) and is designed to regulate the flow of exhaust gas towards the end chamber (9).
  7. 7. The vehicle (1) according to claim 6, characterized in that the silencing device (11) is connected to the end chamber (9) so as to be formed as a single unit with the end chamber (9).
  8. 8. The vehicle (1) according to claim 6, characterized in that the end chamber (9) comprises a tubular body (18) and has an inlet opening (19) connected to the exhaust pipe and an outlet opening (10) opposite the inlet opening (19), and in that the silencing device (11) is arranged above the tubular body (18) on the side opposite the movable partition (23).
  9. 9. The vehicle (1) according to claim 1, characterized in that the movable partition (23) is movable between a maximum expanded position, in which the movable partition (23) causes the end chamber (9) of the exhaust pipe (7) to take a diverging shape in which the cross-sectional area gradually increases as the outlet opening (10) approaches, and a minimum expanded position, in which the movable partition (23) causes the end chamber (9) of the exhaust pipe (7) to take a converging shape in which the cross-sectional area gradually decreases as the outlet opening (10) approaches.
  10. 10. The vehicle (1) according to claim 1, characterized in that said end chamber (9) of said exhaust pipe (7) has two opposite said movable partitions (23), only one of them defining a lower surface of said end chamber (9) facing the road surface and being blown in use by an air flow flowing under said vehicle (1).
  11. 11. The vehicle (1) according to claim 1, wherein the control unit (27) is configured to create the position of the movable barrier (23) at low and medium speeds based solely on the noise damping demand and at high speeds based on the pneumatic demand helping to create the load at high speeds.

Description

Automobile provided with exhaust system with pneumatic effect Cross Reference to Related Applications This patent application claims priority from italian patent application number 102020000032849 filed on 12/30/2020, the entire disclosure of which is incorporated herein by reference. Technical Field The present invention relates to an automobile provided with an internal combustion engine equipped with an exhaust system. Background Automobile model certification regulations mandate manufacturers to limit acoustic emission levels, especially when the automobile is traveling at medium speeds (i.e., when it is traveling through a city center). Thus, the exhaust system (which fulfils the function of releasing the gases produced by combustion into the atmosphere, limiting the noise and pollutant content) is always provided with at least one muffler, which is arranged downstream of the pollutant-reducing device along the exhaust pipe. Generally, the muffler comprises a tubular body having a generally elliptical cross-section and provided with an inlet opening and an outlet opening. A labyrinth is defined within the tubular body defining a path for the exhaust gases from the inlet opening to the outlet opening, said labyrinth generally comprising diaphragms (or baffles) disposed transversely (i.e., perpendicular to the longitudinal axis of the tubular body) to define chambers within the tubular body, and conduits connecting the chambers to one another. In a conventional muffler that ensures that noise at low engine speeds is greatly reduced, the exhaust back pressure generated by the muffler (i.e., the pressure loss generated in the exhaust gas as the exhaust gas flows through the muffler) increases exponentially as the rpm of the internal combustion engine increases (i.e., as the average speed of the exhaust gas increases). Thus, to avoid excessive exhaust back pressure values at high engine speeds (and thus unduly compromising performance at high engine speeds), a bypass pipe is provided that is placed in parallel with the muffler (i.e., designed to bypass the muffler) and is regulated by a bypass valve that remains closed at low engine speeds (thereby maximizing muffler function but sacrificing performance, but performance is not important at low engine speeds) and opens at high engine speeds (thereby reducing exhaust back pressure to acceptable levels). Furthermore, an important aspect in determining a high performance sports car is the "quality" of the sound emitted by the exhaust system, which is a very important perceived feedback during use of the car under extreme conditions. However, known exhaust systems having variable geometry (i.e. provided with one or more electrically or pneumatically controlled valves which may alter the path of the exhaust gas and thus the sound along the exhaust gas system) do not always ensure that the sound emitted by the exhaust system corresponds to the needs of the user. In general, turbocharged engines are disadvantageous because the presence of a turbine along the exhaust pipe and a compressor along the intake pipe adds filtering and reducing effects to the sound level of both the exhaust system and the intake system. Furthermore, recent emission standards have made the use of exhaust gas treatment devices severely detrimental to sound performance, because a second catalytic converter or particulate filter (also known as a GPF, i.e. "Gasoline Particulate Filter (gasoline particulate filter)") must be provided in parallel with the catalytic converter even in a gasoline engine. Patent documents US1483354A, KR20160108625A and GB2274681a describe an exhaust system for an internal combustion engine, in which an exhaust pipe starting from the internal combustion engine has an end chamber with an outlet opening at the end through which exhaust gases are released into the atmosphere, the end chamber of the exhaust pipe having at least one movable partition which can be moved to different positions to vary the width of the outlet opening. In particular, the movement of the movable partition may be performed manually (as described in US 1483354A) or may be performed automatically due to the pressure of the exhaust gases and against the elastic thrust generated by the springs tending to minimize the width of the outlet opening (as described in KR20160108625A and GB2274681 a). Patent application US2008282688A1 describes an exhaust system of an internal combustion engine comprising an exhaust pipe provided with a plurality of ventilation flaps which open automatically as the exhaust gas temperature increases. Disclosure of Invention The object of the present invention is to provide a motor vehicle provided with an internal combustion engine equipped with an exhaust system which complies with the specifications of the type authentication and at the same time can maximize performance by ensuring natural and suitable exhaust noise for racing applications of the motor vehicle. According