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
  • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
  • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
  • F02M51/061—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means
• • 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
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/0012—Valves
  • F02M63/0014—Valves characterised by the valve actuating means
  • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
  • F02M63/0017—Valves characterised by the valve actuating means electrical, e.g. using solenoid using electromagnetic operating means
• • 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
  • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
  • F02M69/04—Injectors peculiar thereto
  • F02M69/042—Positioning of injectors with respect to engine, e.g. in the air intake conduit
  • F02M69/044—Positioning of injectors with respect to engine, e.g. in the air intake conduit for injecting into the intake conduit downstream of an air throttle valve
• • 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
  • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
  • F02M69/30—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines
  • F02M69/32—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines with an air by-pass around the air throttle valve or with an auxiliary air passage, e.g. with a variably controlled valve therein
• • 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
  • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
  • F02M69/30—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines
  • F02M69/32—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines with an air by-pass around the air throttle valve or with an auxiliary air passage, e.g. with a variably controlled valve therein
  • F02M69/325—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel characterised by means for facilitating the starting-up or idling of engines or by means for enriching fuel charge, e.g. below operational temperatures or upon high power demand of engines with an air by-pass around the air throttle valve or with an auxiliary air passage, e.g. with a variably controlled valve therein with an auxiliary injection nozzle therein

Definitions

• the present invention is comprised in the technical field of injection systems for gasoline combustion engines, and is especially applicable to gasoline combustion engines of the type which are used in vehicles such as motorcycles with a reduced cylinder capacity, mopeds and microcars, and in small stationary or transportable apparatuses such as electric generators, motor pumps, capstans, etc.
• a typical electronic injection system for a high-medium power motorcycle usually comprises the following components for controlling the amount of intake gases, at the driver's will, measuring the admitted air flow and supplying the suitable amount of fuel for a correct operation of the engine:
• a throttle body which frequently contains the injector distributing the gasoline downstream of the throttle valve or of the gas control valve and the sensor of its angular position which provides information of the load of the engine at any rotational speed;
• an electric pump in side the gasoline tank usually with a delivery of 20-35 l/h, 2-3 bar of pressure and a consumption of 1 .5A-3A at 12V, and driven by a direct current electric motor and with an internal gear pumping element or with a turbine, this latter pumping element not being self-priming therefore the pump needs to be located in the lower inner area of the gasoline tank;
• an electric injector which, when it is activated, electrically opens the obturator such that the injected gasoline flow depends on the outlet holes, on the difference of pressure on both sides of said holes, controlled by the pressure regulator, and on the electric activation time of the injector, the gasoline flow distributed by the injector depending, for a given injection system, only on the activation time of the injector;
• an intake absolute pressure sensor which with the intake temperature signal allows calculating the intake density, which by the cylinder capacity gives the mass of admitted air and supplying in a suitable proportion the required gasoline; this sensor is only used in the most sophisticated injection, speed-density, systems, whereas in the most elementary systems the throttle-speed (a-n) angle is used, the speed and the phase being a piece of information arriving from an inductive sensors detecting the pitch of the teeth of a phonic wheel integral with the crankshaft;
• bypass an auxiliary air inlet valve which is an electromechanical element controlling, by means of an electric activation, an air flow in parallel with the throttle to obtain an idling prefixed rotational speed at any temperature.
• an electronic control unit or central unit which processes the signals of the sensors and its memory and program data steers the actuators, the injector, the bypass and the gasoline pump to enable a correct operation of the engine.
• Figure 1 shows a feed system of the state of the art for a four-stroke gasoline combustion engine (6) comprising a carburetor (4) conventionally arranged between an air filter (3), to which the carburetor (4) is connected by means of an air feed conduit
• the intake elbow (7) is connected to the intake (6a) of the engine (6) in which an intake valve (6b) is also conventionally arranged.
• the possibilities offered by the electronic control allow optimizing the emissions of the engine by incorporating other components to the system such as ignition, the trivalent catalyst and Lambda probe, EGR valve and others.
• the previously described injection system is currently used in high and medium power motorcycles, in which the cost of the injection system has a certain proportion with respect to the total cost of the vehicle.
• the previously described injection system becomes a very significant fraction of the total cost of the vehicle or apparatus. Therefore, low power combustion engines are currently fed by means of a carburetor.
• the object of the present invention is to overcome the aforementioned drawbacks of the state of the art by means of an injection system for small gasoline engines defined in the attached independent claims.
• the electronic injection device for small gasoline engines of the invention comprises a throttle valve body, which internally has an air passage channel with an air inlet orifice and a mixture outlet orifice, a throttle valve being housed inside said channel.
• An electric gasoline injector is assembled in the body of the valve.
• the device is characterized in that it comprises a sonic nozzle, with one or two throats, coupled with the outlet of the restriction of said electric gasoline injector, in a manner coaxial with the longitudinal axis of the restriction of the injector.
• the mentioned coupling between the nozzle and the restriction assures the perfect coaxial alignment between both elements, and therefore assures the suitable spraying of the gasoline.
• the sonic nozzle is arranged to project a mixture of air and gasoline inside the channel downstream of the throttle valve which is added to the rest of the intake air.
• An air inlet conduit is formed inside the body of the valve and arranged parallel to the longitudinal axis of the body of the valve, said conduit having an air inlet located upstream of the valve, and said conduit having an outlet which ends in an injection chamber supplying air to the inlet of the nozzle through openings allowing the air flow when said nozzle is coupled with the restriction of the injector.
• One of the relevant features of the injection system of the invention consists of the implementation of a "doubly indirect" injection since the restriction of the injector discharges at the pressure of the injection chamber and then the gasoline passes to the intake conduit through the nozzle, a configuration which allows using the described injector with a low level of investments for its manufacture as well as reducing the electric consumption of the injection system.
• the present invention solves the drawbacks of the state of the art by providing a low-cost injection system with an excellent functionality and which furthermore allows the substitution of the carburetor with the gasoline injection system according to the present invention in a direct manner without needing mechanical or electric modifications both in relation to the design of vehicles or apparatuses manufactured for the first time and at the level of re-equipping already existing vehicles and apparatuses provided with carburetors, since it is enough to:
• the injection system of the invention achieves that the difference of speed between the gasoline stream and the air flow is more than 300 m/s, inside the nozzle, which causes an intense nebulization of the injected gasoline stream. This is very beneficial for a good combustion of the air/gasoline mixture, since it reduces both the emissions of
• Negative pressures greater than 0.01 -0.02 bar occur in almost the entire operation field of four-stroke engines with sufficient nebulization quality of the gasoline, particularly one-cylinder engines of up to 150cc in relation to those in which the application of the present invention is particularly useful.
• it can be applied to cylinder capacities that are twice as large without modifying the performance of the components of this gasoline injection system, an application which is highly adapted economically and functionally to this invention.
• two-stroke engines work with lower negative pressure in the intake manifold than four-stroke engines, it is also possible to apply this system to them with a suitable sizing of the parameters of the nozzle, reducing the unwanted effects of the intake-exhaust short circuit by operating with very poor mixtures and with programmed algorithms of fuel cut-off, of the damping of the idle return (dash-pot) and others.
• the relative speed of the gasoline with respect to the air is greater than 300 m/s, in almost the entire field of operation of the engine from the idle to areas close to full gas.
• this relative speed is of the order of 28 m/s with an electric consumption of about 2-3 A at 12V, i.e., with a minimum consumption of 24 W.
• the average electric consumption of the system proposed by the present invention is of 0.3A at 9V, i.e., about 3 W, i.e., the present invention has the advantage of a lower electric power consumption.
• the extremely high speeds with respect to air reached by the gasoline in the nozzle the present invention has the considerable advantage that, due to the effect of the shock wave when the engine works under a partial load, a high mixture homogeneity is generated which allows operating in a wide range of very poor air-gasoline ratios without problems of failures of combustion and low emission of unburnt hydrocarbons and carbon monoxide.
• the pressure of the injection chamber, or area of entrance of air to the nozzle varies slightly from one point of operation of the engine to another due to the pressure drop of the air filter, variable with the engine intake air flow, and acoustic effects in the intake of the engine, these variations of pressure only minimally affect the gasoline flow of the injector, since the jump of pressures through the restriction of the injector is modified, but they are repetitive at each point of operation of the engine and their effect is corrected upon assigning, in the program of the central unit, the injection time for obtaining the desired air-fuel ratio.
• the present invention is especially useful for engines with a small cylinder capacity, as is inferred from the previous description, the developed injection system can also be implemented in combustion engines with various cylinder capacities and numbers of cylinders, it only being necessary for that purpose to adjust the output of the pump and pressure regulator to the maximum cylinder capacity and speed of the engine and the output of the injectors to the cylinder capacity of each cylinder, as well as the throats of the nozzles, associated with each injector, to the air flow of the idle.
• the injection system according to the present invention formed by the pump of low pressure, injector, injection chamber and convergent-divergent nozzle with two throats, coaxially coupled to the restriction, allows the operation with restriction of the injector of the order of 0.4-0.5 mm in diameter if the pressure determined by the pressure regulator is approximately 0.4-0.6 bar.
• a restriction part of the injector of a larger diameter can be provided, or the pressure can be increased to close to 0.8 bar, maintaining the mentioned diameter of the restriction part.
• the injection system according to the present invention has, compared to conventional injection systems, a lower cost. This is due to the fact that investments in high-technology productive processes such as series spark eroding or precision grinding machines, as regards the process for manufacturing the injector the parts of which are obtained, for this injection system, by lathe machining with easily obtainable tolerances and finishes, are not necessary.
• the assembly process can contemplate the unitary fine-tuning of the run of the obturator and the tension of its spring to obtain the specified gasoline flows, for assigned injection times, in the area of the idle and maximum power, operations which can be easily automated.
• the gasoline pump has a lower cost in view of the fact that it operates with low pressure which can be, in engines with a small cylinder capacity, considerably less than one bar, therefore its components can be manufactured with process for injecting plastics adapted for this function, such pump being able to be of the turbine type or of the positive displacement type, the latter being either a gear or a centrifugal vane type.
• Figure 1 is a schematic side elevational view of a carburetor feed system of the state of the art for a low power four-stroke gasoline engine, in which the injection system according to the present invention can be installed.
• Figure 2 is a view similar to that of Figure 1 which includes the injection system of the present invention.
• Figure 3 is a schematic side longitudinal section view of an electric injector according to the invention.
• Figure 4 shows in the top drawing a side elevational view of a sprayer according to the invention formed by a nozzle with two throats coupled to a restricting part.
• the bottom drawing is a longitudinal cross-section view according to section line A-A of the top drawing.
• Figure 5 shows in the top drawing a side elevational view of a sprayer according to the invention formed by a nozzle with a throat coupled to a restricting part.
• the bottom drawing is a longitudinal section view according to section line A-A of the top drawing.
• Figure 6 is an enlarged and cross-section view of a detail of the sprayer assembled in the body of the throttle.
• Figure 7 is a longitudinal section view showing the arrangement of the injection device of the invention.
• Figure 8 is a schematic partial outer perspective view of the arrangement shown in Figure 7.
• FIG 2 shows an embodiment of the injection system of the present invention in substitution of the carburetor feed system shown in Figure 1 , interconnecting a throttle body (1 1 ) between the air filter (3) and the intake elbow (7), and substituting the outlet valve in the gasoline tank (1 ) with an electric gasoline pump (10).
• the injector (9) is incorporated in a throttle body (1 1 ) with an inner air passage (1 1 a) in which there is a throttle valve (12), and with an air inlet (1 1 b) connected to the air feed conduit (5) and a gasoline/air mixture outlet (1 1 c) connected to the feed elbow (7).
• the gasoline pump (10) is located in the outlet of the gasoline tank (1 ) and its outlet is connected to the gas supply inlet (1 1 e) of the injector (9) through the feed tube (8) leading the gasoline to an annular chamber (1 1 d) in the throttle body (1 1 ), this annular chamber (1 1 d) being located communicated with gasoline inlet holes
• the injector (9) is arranged in the throttle body (1 1 ) such that, through a sonic nozzle (16), it injects gasoline to the inner air passage (1 1 a) of the throttle body (1 1 ) between the throttle valve (12) and the mixture outlet (1 1c), i.e., downstream of the valve (12) and it is connected, at its upper area, to a pressure regulator (13) through which non-injected gasoline passes, which gasoline is returned to the gasoline tank (1 ) through a return conduit (14) connected to the tank (1 ).
• the gasoline returned to the tank (1 ) entrains with it all the gasoline bubbles which may have been generated by the high temperatures of the environment of the engine even if the ambient temperature is abnormally high, such as above 50 5 C.
• an electronic central unit comprising a first feed inlet (15a), a second inlet (15b) connected to a rotational speed sensor (not shown in the figures) and a third inlet (15c) connected to a temperature sensor (15d).
• the rotational speed sensor is the same sensor used for the ignition. The sensor of the angular position of the throttle, necessary for knowing the load state of the engine, is not shown in the figure.
• the gasoline pump (10) is of low pressure, its typical operating regime being 0.4-0.7 bar with an output which multiples by several times the maximum gasoline consumption of the engine (6), and with an electricity consumption of 0.2A-0.4A at 9V. Given its limited performance with a total efficiency of approximately 0.04, the gasoline pump (10) can be manufactured with suitable plastic components and with a very low cost.
• the gasoline pressure regulator (13) is assembled in the throttle body, and comprises a cylindrical cavity containing a non-deformable conical obturator (39) at its end, arranged to close against a coaxial circular hole (40) by the action of a compression spring (44) also coaxial with the obturator.
• the pressure regulator (13) ends in a chamber (41 ) through which it is communicated with inlet holes (23) of the injector (9) through a conduit (1 1 f).
• the injector (9), depicted in detail in Figure 3, comprises a ferromagnetic obturator (17) in the form of a piston housed in an inner axial cavity (18b) of a nonmagnetic sleeve (18).
• the obturator (17) has a housing (17a) in which there is inserted with interference a sphere (19) pressed, in a closed position of the injector (9), by a spring (20) located in a cylindrical axial chamber (17b) of the obturator (17), against the edge of a circular passage hole (18d) formed by a constriction (18a) of the sleeve (18).
• the edge of the passage hole (18d) is concave and has a curvature complementary to the curvature of the sphere (19) which projects from the housing (17a) and which is pressed against said edge.
• This complementary configuration can be formed, for example, by impacting, with a controlled load, a sphere of the same diameter as the sphere (19) on a sharp edge with sides at about 127 5 , one of which is the generatrix of a cone tangent to the sphere at 80% of its diameter.
• the gasoline inlet holes (23) end in an inlet chamber (17c) located between the sleeve (18) and the end part of the ferromagnetic obturator (17) which is located close to said holes (23).
• the obturator (17) is the mobile part of a magnetic circuit of a solenoid such that when the coil (21 ) surrounding a part of the sleeve (18) and contained in the casing (9a) is activated by means of an electric signal coming from the central unit (15), the ferromagnetic obturator (17) moves, overcoming the force of the spring (20), from its closed position shown in Figure 3 in which it presses the sphere (19) against the passage hole (18d) of the constriction (18a) towards an open position, performing a run (42), for example, of the order of 0.05 mm, in a direction opposite to the constriction (18a) such that the sphere (19) is separated from the passage hole (18d) of the constriction (18a).
• a run (42) for example, of the order of 0.05 mm
• the gasoline supplied by the gasoline pump (10) after passing through the filter (22) and through the inlet holes (23) in the form of radial boreholes located in the sleeve (18), traverses the obturation area formed by the constriction (18d) and passes through the mouth (18c).
• the cylindrical part (25) internally houses in a coaxial manner a threaded cylinder (27), the first end of which contacts the spring (20) and the rotation of which in a first direction presses the spring (20) whereas its rotation in the opposite direction detensions the spring (20), which allows regulating and blocking the tension of the spring (20) of the obturator (17) additionally to the cylindrical part.
• This second cylindrical part (27) is blocked by the action of the O-rings (26').
• the flow of the injector can be regulated at the specified values in its entire field of action with very restricted tolerances, eliminating the effects of the possible variations of flow capacity of the obturation area and of the final restriction part.
• the two threaded cylinders can subsequently be definitively blocked by providing them with a plastic resin in the rear cavity (28) made in a ferromagnetic sleeve (43) axially housed in the injector (9).
• the present invention comprises a sprayer (33) shown in Figure 4, the function of which is to spray the injected gasoline coming from the injector (9).
• This sprayer consists of the sonic nozzle (16) with two throats and of a restriction (24), both elements being coaxially coupled to one another. More specifically, the restriction (24) is coupled with the inlet (16 a) of the nozzle (16), for which the nozzle has two half rounds (31 , 3 ⁇ ) inserted and elastically retained in a cavity (32) of the restriction (24) due to the elastic deformation thereof.
• the restriction (24) is formed to be inserted inside the mouth (18c) of the injector (9), assuring the perfect axial alignment between the restriction and the throats of the nozzle.
• the restriction (24) furthermore has a narrowing (24a) for the passage of gasoline, the function of which is that of converting the pressure to which the gasoline is subjected into gasoline speed and by the effect of pressure drop, controlling the amount of injected gasoline when the injector is open.
• the coupled injector and the sprayer can be seen assembled in the body of the valve in Figure 6, in which the outlet of the nozzle (16b) discharges in the intake conduit downstream of the throttle (12). It is observed in more detail how the channel (30) ends in the injection chamber (29), from which the air passes into the nozzle through the air inlets (34,34 ' ).
• FIGs 7 and 8 show the circuits and fluidic-hydric components located in the throttle body (1 1 ).
• the gasoline inlet (1 1 e) coming from the pump, which connects with the radial holes of the injector, traverses its obturation area and is introduced by the restriction (24) of the sprayer from which it exits in the form of a stream directed with precision to the center of the throats of the nozzle (16).
• the conduit (30) provides air, coming from upstream of the throttle, to a transverse cylindrical cavity or injection chamber (29), at a pressure which is virtually equal to atmospheric pressure, and enters the nozzle (16) through its openings (34,34 ' ).
• the speed of the gasoline stream coming from the restriction (24) of the sprayer is of about 10 m/s and the speed of air, in the same direction as that of the gasoline, being greater than 340 m/s in the entire area of the nozzle comprised between the first throat and the shock wave, the speed of the air with respect to the gasoline is greater than 300 m/s in said area, with the negative pressure under throttle being equal to or greater than the one mentioned above.
• This relative speed causes a very fine nebulization of the gasoline at the outlet of the nozzle which, mixed with the intake air generates a very homogeneous mixture which allows considerably reducing the emissions of CO and unburnt hydrocarbons as well as the gasoline consumption, feeding the engine with considerably poor mixtures and without problems of driving on roads.
• the diameter of the gasoline stream allows for a circular crown of passage through the first throat of 0.2 mm in thickness, i.e., of difference of radii.
• the sprayer such as the one described, it is possible to manufacture its two components with current mass- production machining equipment, and therefore with normal manufacturing tolerances and economic criteria, assuring a sufficient concentricity between the gasoline stream and the throats of the nozzle and therefore a good nebulization of th e gasoline for each injection system designed and manufactured according to the description of this invention.
• the process for spraying droplets of liquid inside a gas stream is known.
• the average diameter of the droplets resulting from said spraying is smaller the larger the relative speed of the initial droplets of liquid with respect to the air.
• the time necessary for this process is proportional to the initial diameter of the droplets and inversely proportional to the mentioned relative speed.
• the diameter of the initial droplets is a certain fraction of the diameter of the gasoline stream, i.e., of the diameter of the restriction, since they come from the fractioning of said stream at a certain frequency. Given that the diameter of the restriction, and therefore that of the initial droplets, is relatively large as a consequence of the criterion of low electric consumption and easy manufacture of the restriction, it is very convenient to increase the transit time of the gasoline in a field of high speeds of air.
• the nozzle inlet (16a) and the ejection outlet (16b) are communicated by an axial inner passage through which the gasoline stream passes and which comprises a convergent frustoconical segment (16c) into which the gasoline stream enters from the nozzle inlet (16a) and which narrows towards a first throat (35) in which the axial inner passage has its minimum cross-section.
• This throat is sized to block its air flow with 50-70% of the air flow of the idle.
• a divergent frustoconical or stepped segment (16e) is arranged after the second throat (37) ending in the ejection outlet (16b).
• the convergent frustoconical segment (16c) narrows by about 10-15 Q in the direction towards the first throat (35).
• the following cylindrical segment (36) has a section 15-30% greater than the first throat (35).
• the second throat (37) has a section 5-10% greater than the first throat (35).
• the divergent segment (16e) widens by about 2-5 5 from the throat (16d) in the direction towards the ejection outlet (16b) of the nozzle (16).
• the divergent segment (16e) can be formed, as illustrated in the embodiment shown in the figures, by stepped segments with different diameters with inner edges (16f) aligned in a cone which successively form the mentioned widening towards the ejection outlet (16b). Said stepped segments allow reusing for the spraying most of the gasoline decanted in the inner wall of the divergent segment of the nozzle.
• Another alternative proposed by this patent is injecting the gasoline into the intake through a nozzle with one throat according to Figure 5. Inserted, as has been previously described, in a cavity (32) of the restriction of the injector to form the sprayer, its geometric configuration arises from the nozzle with two throats by eliminating the cylindrical central segment (36) and sizing the resulting single throat (35) according to the described criteria.
• the divergent segment is formed by several stepped cylindrical cavities (161) such that they determine circular edges (16f), including that of the throat, aligned in a cone with a 2-5 5 angle.
• the nozzle with one throat is easier to manufacture than the nozzle with two throats but it is conceptually less efficient.
• the nozzle with one throat if the negative pressure under throttle is sufficient, supersonic speeds of air are generated from the throat until the shock wave in the divergent area, after which the speed is subsonic, the distance between the throat and the shock wave being greater the greater the negative pressure.
• the speed is supersonic from the first throat until the second throat, in which it becomes sonic and continues to be supersonic until the shock wave. It is evident that in the case of the nozzle with two throats the residence time of the gasoline in supersonic areas is much greater than in the case of the nozzle with one throat.
• the average size of the droplets will be smaller with the nozzle with two throats.
• the comparative result is substantially equal but with subsonic speeds and lower spraying.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Fuel-Injection Apparatus (AREA)

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• 2010
  • 2010-02-08 ES ES201030160A patent/ES2387207B1/es not_active Expired - Fee Related
• 2011
  • 2011-02-07 EP EP11702236A patent/EP2534366A1/de not_active Withdrawn
  • 2011-02-07 WO PCT/EP2011/051724 patent/WO2011095622A1/en active Application Filing

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