Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M29/00—Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture
  • F02M29/04—Apparatus for re-atomising condensed fuel or homogenising fuel-air mixture having screens, gratings, baffles or the like
• • 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

• This invention relates to the construction of devices for increasing the speed of combustion of the gaseous fuel mixtures used in internal combustion engine particularly, but not exclusively, those which are obtained by the entrainment in air of a volatile liquid fuel such as gasoline.
• a further object of introducing vortices which can have a speed of revolution of some thousands per second, is to provide a scrubbing action on the droplets of fuel arriving from the carburation device ⁇ as these possess too much inertia to follow the motion of the vortices, and are usually present in abundance as a fine mist because it is not normally possible to cause a liquid fuel to evaporate to a true gas prior to arrival at the engine cylinder. There is, therefore a homogenising effect which permits the use of a leaner fuel mixture than is otherwise possible.
• the devices provide surfaces against which large fuel droplets are comminuted by impact.
• the invention provides an internal combustion engine having a cylinder inlet with means for increasin the turbulence of gases passing the inlet, said means comprising elements which define a plurality of slots for the flow thereto and which present edges which are sharp or substantially so.
• the devices for increasing turbulence create vortex motion by constraining the inrushing gas to pass through a number of fine slits defined by bars or the like which present a sharp, or finely radiused edge, to the gas mixture.
• the flanks of the bars may be flat or concave or convexly curved, as may be their downstream faces.
• the bars may be straight or curved in the plane perpendicular to the direction of gas motion and, in the latter case, may be in conoidal formations.
• the slits are preferably of constant width throughout their lengths and number and it is desirable that the bars or ribs defining them should be likewise.
• the slit widths may, however, be variable in embodiments in which two of the rib bearing devices are arranged to slide relatively on a mutually plane interface, the combination then serving also as an engine throttling means .
• the devices for increasing turbulence may be installed at any position between the carburation means and the engine cylinder, but are, desirably, as close to the latter as possible in order ⁇ ,o reduce the volume of gas which tends to beco quiescent during the non-inductive strokes of the engine
• the best position in motors utilising mushroom-type poppet valves is immediately close to the upstream side of the valve seat, a central hole being provided in the device to permit the valve stem to work through It with a slight clearance.
• Another practical position is at the inlet manifold connection to the block.
• the sheet-like jets of gas issuing from the slits immediately break up into vortices revolving intermittently In contrary directions; the process may be initiated by the edge tones produced by the sharp upstream edges of the ribs In a manner frequently utilised in musical wind instruments.
• the resulting small scale disturbance in the gas is easily able to persist for the duration of the induction and compression strokes of the engine piston until the insta of ignition.
• the devices are primarily intende to be used in engines powered by air-entrained fuel, the may also prove of value in cases when the fuel is inject directly Into the cylinders.
• Figures 1 and la_ are respectively plan and cross-section of a plate formed with slots, forming one means according to the invention for Increasing turbulence of gases;
• Figures 2 and 2a are respectively sectional pl and cross-sectional view of a duct with further means according to the invention for increasing turbulence in gases flowing through the duct 5
• Figures 2b and 2£ are cross-sectional view r s showing respectively two further forms of means for increasing turbulence of gases*
• Figure 3 is a diagram Illustrating the mathematical definition of an Involute curve
• Figures 4a and 4b are respectively plan and
• Figure 5 is a cross-sectional view of the inlet arrangement of an internal combustion engine showing a turbulence increasing means in an operative position;
• Figures 6 and 6 _ are respectively a plan and a sectional view of a duct wherein are mounted two slotted plates;
• Figures 7 and 7a are respectively views in plan and section of two plates both formed with involute slots, the combination forming a further example of means according to the invention for increasing the turbulence of gases.
• Figure 1 shows a plate which is suitable for use in a duct which has been flared to a square to accommodate it.
• the plate 11 is provided with equally spaced slits 12 of equal widths formed by parallel ribs 13, the sides . of which are tapered to merge into sharp edges 14 on the upstream side of the plate.
• Cross- sectional Figure la. shows the slits entering partially circular cavities 15 which help to promote the formation of strong vortices. This artifice may be used with any of the devices herein described.
• Figure 2 is a view down a circular duct 21, in which are mounted a series of concentric rings 22, held In position by at least three support bridges 23.
• the rings 22 are of triangular cross-section, presenting sharp edges to the inrushing gas as shown in the sectiona diagram 2 _.
• Figure 2b_ shows a series of three such devices (but without support bridges) , closely spaced and in staggered array, the rings 22 having rounded downstream edges, a style which may be adopted in all embodiments. With the less volatile fuels, this is useful in preventing the accumulation of large globules of fuel at the downstream edges of the rings.
• Figure 3 shows a method of generating the mathematical involute to a central circle 31 by unwinding an inextensible cord 32 from a drum of the same diameter. It will be seen that the curves outside the central circle are parallel throughout their lengths. This is the only known spiral with which this result can be realised and is utilised in the construction of the devices to be described hereinafter. Other spirals could be used, but are not so effective.
• Figure 4 shows a plate 41 perforated with equi- angularly spaced slits 42 of the circular involute type described. It will be seen that the wid-ths of both slits and ribs are constant throughout their respective lengths as shown at 43 and 44. The aerodynamic conditions are therefore the same around circles of given radius and the arrangement provides the maximum possible total length of slit within the outer defining circle.
• Figure 4a shows further alternative rib cross-sections 45 and 46. This type of device is particularly suitable for installation in each duct of a distribution manifold where it meets the engine block of a multi-cylinder engine.
• Figure 5 shows a plate 51 mounted immediately upstream of a mushroom type inlet poppet valve. In this case, the inner ends of the ribs, which are similar In plan to those shown in Figure 4, terminate in a boss 52 provided with a central hole to enable the valve stem to slide through with a slight clearance.
• Figure 6 shows a pair of plates 61, similar to those depicted in ' Figure 4, together with a spacing ring 62.
• Plates 61 are orientated so as to be out of angular alignment by one half of the angular rib pitch, the edges of the second plate then appearing directly in line with the slits of the first plate, and being thus throughout their lengths.
• the upstream plate is shown provided with a conical deflector 63 to direct the gas the more smoothly towards the slits.
• the upstream plate is shown provided with yet another possible type of rib section of arcuate form 64.
• the arrangement When the plates are separated by a distance of between 2 to 5 times the slit width, the arrangement is found to emit a high pitched musical note, indicating the presence of strong and stable vortex formations. Resistance to gas flow is but little increased by the addition of the second ribbed plate and the arrangement is particularly satisfactory for comminuting large fuel droplets such as those arriving at the cylinder as a resul.t of the fuel film deposited on the walls of cold manifolds and being gradually swept along same. Large fuel droplets are able to pass through the engine without becoming completely burnt and are the most significant cause of hydrocarbon pollution In the atmosphere.
• Figures 7 and 7a_ give views of a throttling device consisting of two plates 71 pierced with slots 72 of the circle involute type previously described. Relative rotation of the plates on a common flat face about a common axis 73 results In the appearance of slits 74, all of which are the same width throughout their lengths unless the device has been deliberately designed to ensure that the slits are not opened simultaneously, which may sometimes be of advantage, particularly when it is desirable to leave one or more of the slits permanently slightly open when the engine is idling.
• the slots 72 are shown as having parallel sides, but .both upstream and downstream of the necessary common flat face the slots may be of any of the forms already described.
• the throttle may also be used In conjunction with correspondingly slotted plates as Indicated In Figure 6.
• This throttle is particularly suitable for arrangements In which it is desired to provide a separate throttle for each cylinder of a multi-cylinder engine- They may be installed where the induction manifold meets the cylinder block, selective operation being possible with a suitable arrangement of linkwork or cams, which may, if desired, shut down one or more of the cylinders completely when full engine power Is not needed.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combustion Methods Of Internal-Combustion Engines (AREA)

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• 1981
  • 1981-11-12 WO PCT/GB1981/000241 patent/WO1982001746A1/en not_active Application Discontinuation
  • 1981-11-12 EP EP81903101A patent/EP0064524A1/en not_active Withdrawn
  • 1981-11-12 AU AU77299/81A patent/AU7729981A/en not_active Abandoned
  • 1981-11-13 IT IT68478/81A patent/IT1146716B/it active

Non-Patent Citations (1)

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