Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B27/00—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues
  • F02B27/04—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues in exhaust systems only, e.g. for sucking-off combustion gases
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the invention relates to an exhaust system for an internal combustion engine, and particularly for use on a four stroke internal combustion engine such as motor vehicle engine, and to a method of exhausting such an engine.
• a method of exhausting the gases of combustion from a cylinder of a multi-cylinder internal combustion engine including the step of generating a negative pressure by utilising the exhaust gas flow of a fired cylinder to create a negative pressure or partial vacuum at the exhaust port of another cylinder while that cylinder is being exhausted.
• an exhaust system for an internal combustion engine having a plurality of cylinders comprising a primary exhaust pipe connected to the exhaust port of each cylinder, and a secondary exhaust pipe connected between a primary exhaust pipe of a first cylinder and that of a second cylinder so that the velocity of exhaust gas from the first cylinder will create a negative pressure or partial vacuum at the exhaust port of the second cylinder during the exhaust stroke of the second cylinder.
• the secondary exhaust pipes may join the primary pipe of one cylinder to that of the next cylinder in the firing order of the engine.
• the engine may preferably be a four stroke internal combustion engine.
• Figure 1 is a diagrammatic view of an exhaust system according to the invention
• Figure 2 is a fragmentary side elevating of a cylinder head of a four stroke internal combustion engine incorporating the exhaust system of Figure 1 and embodying the invention.
• Figure 3 is a fragmentary sectioned side elevation of a junction of exhaust pipes in the system of Figure 1.
• Figure 1 illustrates a four cylinder four stroke internal combustion engine 10 having a primary exhaust pipe 12,14,16 and 18 connected respectively to the exhaust port of each cylinder of the engine, and a secondary exhaust pipe 20,22,24 and 26 connected respectively to the primary exhaust pipe of the previous cylinder in the firing sequence or firing order of the engine 10.
• the firing order of the engine in this embodiment of the invention is 1,2,4,3, therefore pipes 12 and 22,14 and 26, 16 and 20, and 18 and 24 are connected in pairs.
• the primary and secondary exhaust pipes of the engine 10 are joined in their respective pairs in respective junction boxes 28 which themselves are joined by further pipes 30 to a main pipe 32.
• the secondary pipes 20,22,24 and 26 are joined to the primary pipes 12,14,16 and 18 at the exhaust ports of the engine as illustrated in Figure 2 with the junction apertures between the pipes for example the pipes 12 and 20 shown, being located out of the direct exhaust gas stream from the ports.
• a suitable deflector 34 may be located in the primary pipes upstream of the junction apertures with the secondary pipes. This deflector 34, in the form of an inclined plate, may be situated closer to the engine, at the position where the primary pipe 12 is connected to the port.
• the diameter of the free ends of the primary pipes are narrowed in the junction boxes 28, as shown in Figure 3, to increase the velocity of exhaust gas leaving the pipes. It is important that the configuration of the pipes in the junction boxes 28 be such that little gas turbulence is created at the junctions to minimise back pressure in the primary and secondary pipes.
• exhaust gas under pressure is discharged from the exhaust port of that cylinder 1 through the primary pipe 12 and into the pipes 30 and 32.
• a very slight gas discharge may occur through the secondary pipe 20 into the junction box 28 of cylinder 3 but this is of no consequence to the operation of the system.
• the exhaust gas which leaves the free end of the pipe 12 in the junction box 28 under substantial velocity expands into the pipe 30 and substantially drops the pressure in the secondary pipe 22 to create a negative pressure through the pipe at the exhaust port of cylinder 2.
• the negative pressure at the exhaust port of cylinder 2 assists in rapidly reducing the pressure in that cylinder as soon as the exhaust valve opens to reduce the pumping load on the piston in the cylinder.
• the reduced pressure also ensures complete scavaging of the exhaust gas from the cylinder before the exhaust valve closes.
• a further small drop in pressure is created in the system at the junction of the pipes 30 with the pipe 32.
• a Merlyn Formula Ford car was fitted with a standard Ford 1.6 Kent engine together with two competition exhaust systems.
• the chassis dynometer was set up with an inertia setting of 2500 lbs and a road load power setting of 2.4 KW at 50 km/h. This load setting was based upon the values contained in the table of road load power verses inertia contained in ECE1503 regulations.
• This load and inertia were set to simulate the test conditions of a 1600 cc Ford Cortina.
• the first series of tests was carried out on the vehicle as supplied with a tubular 4 into 1 silenced exhaust system.
• a system embodying the invention improves the power, economy and emissions of an internal combustion engine.
• the system embodying the invention provides, it will be understood, a "tuned" exhaust system in which pulses and relative pressure levels in different branches of the exhaust system provides improved exhaust and scavaging of the engine

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust Silencers (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=10519974

Family Applications (1)

Country Status (4)

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Family Cites Families (4)

• 1982
  • 1982-02-24 IT IT19819/82A patent/IT1149671B/it active
  • 1982-02-24 AU AU81418/82A patent/AU8141882A/en not_active Abandoned
  • 1982-02-24 EP EP82900557A patent/EP0072829A1/en not_active Withdrawn
  • 1982-02-24 WO PCT/GB1982/000062 patent/WO1982002925A1/en unknown

Non-Patent Citations (1)

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