MXPA06008741A - Fuel enrichment system for carburetors for internal combustion engines - Google Patents

Abstract

A carburetor for an internal combustion engine having a body that fastens at a first end to an air filter and at a second end to the intake port of a cylinder head. The body has an intake bore formed in the first end that receives air from the air filter, a throttle bore formed in the second end that provides a fuel/air mixture to the intake port, and a venturi formed between the intake bore and the throttle bore that receives air from the intake bore, provides fuelto form a fuel/air mixture, and provides the fuel/air mixture to the throttle bore. A bore is formed in the body from the venturi and receives a nozzle that communicates fuel to the venturi. A fuel enrichment system, which is responsive to the vibration of the engine, has a passage that communicates air from the intake bore, through the passage, to the nozzle. A valve seat is disposed within the passage and also has a passage to allow the flow of air therethrough. A ball is disposed within the passage of the fuel enrichment system that seats against the valve seat when the engine is below engine cranking speeds to prevent the passage of air through the valve seat. When the engine is above engine cranking speeds, the ball will resonate within the passage of the fuel enrichment system and unseat from the valve seat, thereby allowing the flow of air around the ball and through the valve seat.

Description

FUEL ENRICHMENT SYSTEM FOR CARBURETORS FOR INTERNAL COMBUSTION ENGINES FIELD OF THE INVENTION The present invention relates to internal combustion engines. In particular, the present invention relates to fuel enrichment systems for carburetors for internal combustion engines. BACKGROUND OF THE INVENTION Internal combustion engines require a large proportion of fuel in the fuel / air mixture produced in the carburetor (enrichment) during the start-up speed of the engine to provide an easier starting of the engine. Currently, in internal combustion engines there are two main methods to provide the correct fuel enrichment during startup. The first method is by manually or electrically activating a choke plate. The throttle plate is located within the intake port of the carburetor and can be opened and closed to allow the desired amount of air to flow into the intake port. When open, the choke plate completely opens the intake port and allows air to flow through it. When closed, throttle plate REF: 174843 blocks the intake port except for the perforations in the throttle plate, which have sufficient area to admit a predetermined amount of air flowing into the intake port to create an enrichment appropriate for starting. A disadvantage to this method of fuel enrichment is that it requires the interaction of an operator. If an engine is difficult to start, the operator must completely close the throttle plate to properly enrich the engine to start it. If the throttle plate is not completely closed, sufficient fuel may not be supplied to the carburetor and the engine will continue to have difficulty starting. Additionally, once the engine is running, the operator must remember to open the throttle plate or the engine will continue working in enrichment conditions which will cause it to continue operating abruptly. A second drawback for this fuel enrichment method is that it may also be prone to over-enrichment, such as if some or all of the perforations in the stator plate will become blocked, or sub-enriched, such as if the stator plate is not completely closed. Over-enrichment can cause a rough start and / or drowning. The second method is through a manual or electrical activation of a primer bulb. The primer bulb is typically integrated into the carburetor body or mounted to the motor assembly. When the primer bulb is pumped, an air or fuel pressure is forced into the fuel circuit that drives the fuel into the regulator orifice of the carburetor. However, each of these methods has its own particular disadvantages. The first major disadvantage with the old methods of fuel enrichment is that operator interaction is required. When manually activated, both previous methods may result in not providing sufficient fuel to the carburetor and thus cause starting difficulties. The second major inconvenience is that both of the above methods are prone to over-enrichment causing a heavy boot and / or drowning or sub-enrichment. Both avoid an easy starting of the motor. It would therefore be convenient if a fuel enrichment system for a carburetor of an internal combustion engine could be designed in a way that does not require operator interaction and that avoids the problem of sub or over enrichment. SUMMARY OF THE INVENTION One aspect of the present invention is a carburetor for an internal combustion engine having a body. A first end of the body holds an air filter and a second end of the body attached to an intake port of a cylinder head. An intake orifice is formed at the first end and a regulator orifice is formed at the second end. A venturi is formed between, and interconnects the intake orifice and regulator orifice. A hole extends from the venturi through the body to provide fuel to the venturi. A fuel hub has walls that define an internal volume and is secured to the body. A fuel enrichment system is sensitive to engine vibration and has a conduit that is formed in the body. The conduit has an inlet communicating with the intake orifice and an outlet communicating with the orifice. The fuel enrichment system prevents the flow of air through the duct when the engine is running at a speed lower than the idle speed and allows the flow of air through the duct when the engine is working at a speed greater than the starting speed . This provides for the correct enrichment of fuel during engine ignition without operator intervention, avoids over / under-enrichment problems by providing a predetermined air / fuel mixture during ignition, and allows quick and easy engine start-up.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a first perspective view of a single cylinder engine, taken from one side of the engine on which are located an electric starter motor and a cylinder head. Figure 2 is a second perspective view of the single-cylinder engine of Figure 1, taken from a side of the engine on which an air cleaner and an oil filter are located. Figure 3 is a third perspective view of the single-cylinder engine of Figure 1, in which certain parts of the engine have been removed to show additional internal parts of the engine. Figure 4 is a fourth perspective view of the single-cylinder engine of Figure 1, in which certain parts of the engine have been removed to show additional internal parts of the engine. Figure 5 is a fifth perspective view of portions of the single cylinder engine of Figure 1, in which an upper part of the crankcase has been removed to show the interior of the crankcase. Figure 6 is a sixth perspective view of portions of the single-cylinder engine of Figure 1, in which the upper part of the crt is shown in exploded view of the base of the crankcase; Figure 7 is a top view of the single-cylinder engine of Figure 1, showing the internal components of the engine shaded in gray. Figure 8 is a perspective view of the components of a valve train of the single-cylinder engine of Figure 1. Figure 9 is a top view of the single-cylinder engine carburetor of Figure 1. Figure 10 is a front view of the single-cylinder engine carburetor of Figure 1. Figure 11 is a cross sectional view of the carburetor of Figure 9 taken along line AA. Figure 12 is a cross sectional view of the carburetor of Figure 9 taken along line B-B. DETAILED DESCRIPTION OF THE INVENTION With reference to Figures 1 and 2, there is shown a 4-stroke, single cylinder, internal combustion engine 100 designed by Kohier Co. of Kohier, Wisconsin that includes a crankcase 110 having a cylinder 160 formed in a side wall of the crankcase 110, a cover 290 fastened to the upper part of the crankcase 110, and a fan housing 120 mounted on top of the cover 290. Within the fan housing 120 are a fan 130 and a handwheel 140. The engine 100 further includes a starter electric motor 150 mounted to the cover 290 and a cylinder head 170, which has a proximal end secured to the crankcase 110 and extends laterally outwardly from the sidewall of the crankcase 110 to completion at a distal end. A camshaft cover 180 is fastened to the distal end of the cylinder head 170 and defines a cavity therein which forms a valve box, which houses the valves and other components of the valve train, which will be discussed later in more detail. Attached to the cylinder head 170 is an exhaust port 190 shown in Figure 1 and an intake port 200 shown in Figure 3. As known sufficiently in the art, during operation of the engine 100, a piston 210 (see Figure 7) moves back and forth inside the cylinder 160 moving away and approaching the cylinder head 170. The displacement of the piston 210 in turn causes the rotation of a crankshaft 220 (see Figure 7), like the rotation of the fan 130 and the flywheel 140, which are coupled to the crankshaft 220. The rotation of the fan 130 cools the motor, and the rotation of the flywheel 140, causes a relatively constant rotational momentum that must be maintained. Especially with reference to Figure 2, the engine 100 further includes a carburetor 600, coupled to the intake port 200, and an air filter 230 coupled to the carburetor 600, as described. in more detail below. The air filter 230 filters the air required by the engine before supplying the air to the carburetor 600. The air from the air filter 230 is mixed with the fuel within the carburetor 600 to create a fuel / air mixture which is then supplied from the carburetor 600 to the intake port 200. The air / fuel mixture supplied to the intake port 200 is communicated within the cylinder 160 by means of the cylinder head 170, and the combustion gas of the cylinder 160 leaves the engine as it flows from the cylinder 160 through the cylinder head 170 and then out of the exhaust port 190. The inflow of the air / fuel mixture and the flow of The output of the combustion gases is governed by means of an inlet valve 240 and an outlet valve 250, respectively (see Figure 8). Also according to that shown in Figure 2, the engine 100 includes an oil filter 260 mounted to the cover 290, opposite the starting electric motor 150, through which the oil of the engine 100 is passed and filtered. Especially, the oil filter 260 is connected to the crankcase 110 by means of the inlet and outlet lines 270, 280 respectively, by which the pressurized oil is supplied inside the oil filter 260 and then is returned from the oil filter 260 towards the crankcase 110. With reference to Figures 3 and 4, the engine 100 is shown with the fan housing 120 removed to show the cover 290 of the crankcase 110. With respect to Figure 3, in which the fan 130 is also removed. and the flywheel 140, a coil 300 is shown which is mounted to the cover 290 and generates an electric current based on the rotation of the fan 130 and / or the flywheel 140, which function together as a magnet. Additionally, the cover 290 of the crankcase 110 is shown to have a pair of lobes 310 covering a pair of gears 320 (see Figures 5 and 7-8). With respect to Figure 4, the fan 130 and the flywheel 140 are shown above the cover 290 of the crankcase 110. Additionally, Figure 4 shows the engine 100 without the cylinder head 170 and without the camshaft cover 180, to more clearly show a pair of tubes 330 through which a pair of push rods respectively 340 extends. Push rods 340 extend between a pair of camshafts 350 and a pair of cams 360 (see Figure 8) within the rter 110, according to what will be discussed later. Again with reference to Figures 5 and 6, the engine 100 is shown with the cover 290 removed from the crankcase 110 and shown with a separate part-section to exclude portions of the engine extending beyond the cylinder 160 such as the cylinder head. cylinder 170. With respect to Figure 6, the cover 290 of the crankcase 110 is shown above the crankcase 110 in an exploded view. The cover 290 and the crankcase 110 are manufactured as two separate pieces so that, for the purpose of accessing the crankcase 110, someone can physically remove the cover 290 from the crankcase 110. Also, as shown in Figure 5, the torque of gears 320 inside the crankcase 110 are supported by, and rotate about the respective shafts 410, which in turn are supported by the crankcase 110. With reference to Figure 7, a top view of the engine 100 is provided in which additional internal engine components are shaded gray. In particular, Figure 7 shows the piston 210 inside the cylinder 160 which will engage the crankshaft 220 by means of the connecting rod 420. The crankshaft 220 in turn is coupled to a rotary counterweight 430 and reciprocal weights 440, which they balance the forces exerted on the crankshaft 220 by the piston 210. The crankshaft 220 is also in contact with each of the gears 320, and in this way communicates the rotational movement to the gears. In the present embodiment, the axes 410 on which the gears 320 are supported, have the ability to communicate oil from the bottom of the crankcase 110 up to the gears 320. The input line 270 to the oil filter 260 is coupled to one of the shafts 410 to receive oil, while the outlet line 280 from the oil filter is coupled to the crankshaft 220 to supply lubrication thereto. Figure 7 further shows a spark plug 450 located on the cylinder head 170, which provides the electric spark during the combustion moment of the engine to cause the combustion that occurs inside the cylinder 160. The electrical energy for the spark plug 450 is provided by coil 300 (see Figure 3). Further with reference to Figure 7, and in addition to Figure 8, the elements of a valve train 500 of the engine 100 are shown. The valve train 500 includes the gears 320 that rest on the axes 410 and also includes the cams 360 below the gears, respectively. Additionally, respective cam roller arms 510 are mounted so that they can rotate to the crankcase 110 and extend to rest on the respective cams 360. The respective push rods 340 in turn rest on the respective cam roller arms 510. As the cams 360 rotate, the push rods 340 are temporarily forced out of the crankcase 110, by the camshaft arms 510. This causes the camshaft 350 to swing or rotate, and consequently cause the camshafts to rotate or rotate. respective valves 240 and 250 open towards the crankcase 110. However, the cams continue to rotate, however, the push rods 340 are driven by the cam roller arms 510 to return inward to their original positions. A pair of springs 520 positioned between the cylinder head 170 and the camshafts 350 provide the force tending to swing the camshafts in directions that tend to close the valves 240, 250, respectively. In addition as a consequence of this forcing action of the springs 520 on the camshafts 350, the push rods 340 are forced to return to their original positions. With reference to Figures 9-12, the carburetor 600 of the internal combustion engine 100 is shown. The carburetor has a body 610 that forms the main structure of the carburetor 600. The body 610 has a first end 612, which is engaged and fastened with the air filter 230, and a second end 614, which engages and is clamped with the intake port 200. Specifically with reference to Figures 11 and 12, transverse sectional views are shown of the carburetor 600 flush along the lines AA and BB of Figure 9. The carburetor body 610 has an integrated neck 530 projecting from the bottom of the body 610 and extending down therefrom. A fuel bucket 620 is fastened to the neck 530 by a hub screw 630. The fuel bucket 620 has walls 622 that define an interior volume 624 to contain fuel and extend upward to contact the bottom of the body 610. A gasket 640 is positioned between the lower portion of the body 610 and the fuel bucket 620 to prevent leakage of fuel between the fuel bucket 620 and the body 610. Specifically with reference to Figure 11, a cylindrical bore 650 is formed on one side of the body. carburetor body 610 and has a proximal end on the outer surface of the body 610 and extends generally horizontally within the body 610. The orifice 650 transits approximately 90 degrees in the direction between the proximal end and the distal end so that the distal end of the hole 650 extends generally vertically within the body 610 from the lower portion of the body 610 so that the end distal communicates with the inner volume of the fuel hub 624. An input adapter 780 is received within the proximal end of the orifice 650 and is secured by means of a snap fit. The inlet adapter 780 interconnects the carburetor 600 and a fuel tank (not shown) and allows the flow of fuel from the fuel tank into the proximal end of the orifice 650 by means of gravity feed or a fuel pump. A fuel control valve is disposed within the orifice 650 and includes an inlet seat 790 and a bolt 840. The inlet seat 790 is received within the distal end of the orifice 650 and is secured by means of a snap fit. The entry seat 790 has an integrally formed side wall 800 and an upper wall 820. The side wall 820 is generally cylindrical and defines an inner conduit 810. The upper wall is formed integrally at one end of, and perpendicular to the wall side 800 and includes an orifice 830 therethrough which allows fuel flow from the orifice 650 through the conduit 810 through the inlet seat 790. The bolt 840 is received within the entry seat 790 and has a integrally formed tip 870, a body 880, and an end 890. The body 880 is received within the inlet seat passage 810 and is shaped so that fuel can flow through the conduit 810 around the body 880. The tip 870 extends from the body 880 upwards towards the upper wall of the valve seat 820 and has a conical shape so that the tip 870 sits against the hole 830 in the upper wall. 820 to prevent fuel flow through the orifice 830 when the bolt 840 is in its uppermost position, as shown in Figure 11. The end 890 extends from the body 880 opposite the tip 870, protruding out of the entry seat, and is coupled to a float 900, which will be described in more detail below, whereby the position of the bolt 840 is controlled by the movement of the float 900.

The float 900 is disposed within the inner volume of the fuel hub 624 and is rotatably held with a pair of support arms 920 (only one is shown), which are integral with the carburetor body 610 and extend towards down from the bottom of the body 610, by a rotary bolt 960. The float 900 has a recessed body 910 that extends around the neck of the carburetor body 530 (see Figure 12) and floats on the fuel in the fuel bucket 620 by what the float rises when the amount of fuel in the fuel bucket 620 is increased and lowered when the amount of fuel decreases in the fuel bucket 620. The float 900 also has an arm 930, formed integrally with the body 910 , which has a lower protrusion 950 and a pair of upper protuberances 940 (only one is shown) which engage the bolt end 890 so that the lower and upper protuberances erior 950, 940 will raise and lower the bolt 840 as the arm 930 rotates on the rotary bolt 960. During operation, fuel from the fuel tank flows through the inlet adapter 780 into the orifice 650. From the hole 650 the fuel flows through the hole 830 in the upper wall 820 of the inlet seat 790 and through the inlet seat conduit 810, which flows around the bolt 840, towards the inner volume 624 of the fuel hub 620. According to the amount of fuel in the 620 fuel bucket increases the 900 float rises. As the float 900 is raised the arm 930 is rotated clockwise (according to that shown in Figure 11) around the rotary bolt 960. This causes the lower protrusion 950 of the float arm 930 to push against the bolt end 980, which moves bolt 840 further into valve seat 790. When the amount of fuel in fuel bucket 620 reaches a predetermined level, bolt 840 is moved into its uppermost position (as shown in Figure 11) which seats the tip 870 against the entry seat hole 830, thereby preventing the flow of fuel through the inlet seat 790 into the fuel hub 620. According to the quantity of fuel in the fuel bucket 620 decreases the float 900 low. As the float 900 lowers, the arm 930 is rotated counterclockwise (as shown in Figure 11) around the rotary bolt 960. This causes the upper protuberances 940 of the float arm 930 to pull against the bolt end 890, which moves the bolt 840 further out of the entry seat 790 by disengaging the bolt tip 870 from the entry seat hole 830, thereby allowing fuel to flow through the entry seat 790.

Specifically with reference to Figure 12, an intake orifice 700 is formed in the first end 612 of the carburetor body 610 and communicates with the air filter 230. A regulator orifice 720 is formed in the second end 614 of the body 610 and communicates with the intake port 200. A venturi 710 is formed in the center of the body 610 between the intake orifice 700 and the regulator orifice 720 and communicates with both the intake orifice 700 and the regulator orifice 720 by so that the air from the intake orifice 700 passes inside the venturi 710 and the venturi 710 towards the regulator orifice 720. A generally vertical orifice 712 is formed in the lower portion of the body 610 and extends from a proximal end in the venturi 710 down through the neck 530 of the body 610 to a distal end. The proximal end of the hole 712 communicates with the venturi 710 and the distal end of the hole 712 receives the cube screw 630, which holds the fuel hub 620 to the body 610 and closes the distal end of the hole 712. A fuel injector 770 is received within a hole in the neck 530 and allows the flow of fuel from the interior volume of the fuel hub 624 to the orifice 712. A nozzle 730 is received within the orifice 712 and communicates the fuel that is received into the orifice of hole 712 with venturi 710 during engine operation other than in a vacuum. Alternatively, rather than having a separate injector nozzle 730 within the hole 712, the hole 712 could have the shape to perform the function of the nozzle 730 and the nozzle 730 could be removed. A vacuum tube 740 has a proximal end which is secured within a bore 660 formed in the upper portion of the body 610 and extends downwardly through the venturi 710 into the nozzle 730 and terminates at a distal end inside the nozzle 730. If a nozzle 730 is not used, as described above, the vacuum tube 740 would extend downwardly within the hole 712 and end at the distal end within the hole 712. The bore 660 is closed above the end proximal of the vacuum tube 740 by means of a pressure-setting steel ball 670, or by other means for closing the perforation. The vacuum tube transfers fuel from the orifice 712 to the regulator orifice 720 during the vacuum operation of the engine. A regulating valve 750 is mounted so that it can rotate within the regulator orifice 720 and is connected to a regulating control 760, which controls the orientation of the regulating plate 750. The orientation of the regulating plate 750 controls the amount of mixing of air / fuel passing through regulator orifice 750 within intake port 200, as described further below.

During operation, air flows through the air filter 230 into the intake port 700 and from the intake port 700 to the venturi 710. In the venturi 710 the air pressure is reduced, which creates a vacuum within the the nozzle 730. The vacuum formed in the nozzle 730 sucks fuel from the fuel hub 620 through the fuel injector 770 and into the hole 712 in the neck 530 of the carburetor body 610. The fuel in the orifice 712 flows through from nozzle 730 and inside venturi 710 where it mixes with the air to produce an air / fuel mixture. The air / fuel mixture of the venturi 710 then flows into the regulator orifice 720 and from the regulator orifice 720 into the intake port 200. The regulator plate 750 rotates within the regulator orifice 720 to control the flow of the air / fuel mixture from the regulator orifice 720 to the intake port 200. Again with reference to Figure 11, a generally horizontal orifice 702 is formed in the carburetor body 610 and extends from the intake orifice 700 (see Figure 10) inside the body 610, so the hole 702 communicates with the intake orifice 700. A generally vertical orifice (not shown) is formed in the body 610 and extends from the horizontal hole 702 through the lower part of the body 610, whereby the vertical orifice is communicates with both the horizontal hole 702 and the inner volume of the fuel cube 624. The horizontal hole 702 and the vertical hole define a cube vent, which interconnects the intake orifice 700 and the inner volume 624 to equalize the pressure within the interior volume 624 by expelling air from the interior volume 624 towards the intake orifice 700 as the amount of fuel in the interior volume 624 increases and by supplying air from the intake orifice 700 to the interior volume 624 as the amount of fuel in the interior decreases. the interior volume 624. Additionally, a fuel enrichment system is shown that provides enrichment of the e correct fuel during ignition without the intervention of an operator, thereby avoiding the problems of sub or over enrichment. The fuel enrichment system has a conduit having an inlet 680 communicating with the horizontal hole 702 of the bucket vent and an outlet 690 communicating with the nozzle 730. Alternatively, the inlet 680 of the conduit could also communicate directly with the inlet orifice 700 or connecting with the inlet orifice 700 in some manner, as long as air can pass inside the conduit from the inlet orifice 700 and from the inlet orifice 700 within the conduit. Additionally, the outlet 690 of the conduit could also communicate directly with the orifice 712 in the body if a nozzle 730 is not used, as described above, or directly with the venturi 710. In the preferred embodiment, the conduit of the Enrichment is formed by a generally vertical cylindrical bore 370 and a generally horizontal bore 380. The generally vertical cylindrical bore 370 formed in the carburetor body 610 extending from a proximal end at the inlet 680 of the duct to a distal end in the bottom of the carburetor body 610, whereby the vertical orifice 370 communicates with the horizontal hole 702 of the hub vent. The generally horizontal hole 380 is also formed through the side of the carburetor body 610, opposite the orifice 650 that receives the inlet adapter 780. The horizontal hole 380 is generally perpendicular to, and intersects vertical orifice 370 and extends from a proximal end on the outer surface of the carburetor body 610 to a distal end at the outlet 690 of the conduit, whereby the distal end of the orifice 380 communicates with the nozzle 730, and the air in the vertical orifice 370 can flow through the horizontal hole 380 and into the nozzle 730. The proximal end of the orifice 380 is sealed by means of a pressure-setting steel ball 390, or by other means for sealing the orifice 380, to prevent leakage of air from the horizontal orifice 380 towards the atmosphere. A valve seat 460 is received within the distal end of the vertical orifice 370 and is secured by means of a snap fit or other securing means. The valve seat 460 is cylindrical and extends from a proximal end, located at the distal end of the hole 370, to a distal end. The proximal end of the valve seat 460 has a diameter approximately equal to the diameter of the orifice 370 whereby the proximal end of the valve seat 460 will seal the orifice 370 and prevent air from entering the orifice 370 in the inner volume of the hub 624. In the preferred embodiment, the diameter of the valve seat 460 decreases as it approaches the horizontal hole 380 and then increases again as the horizontal hole 380 passes so that the diameter of the valve seat 460 over the horizontal hole 380 again is approximately equal to vertical hole diameter 370 to prevent air from the orifice 370 from entering the horizontal hole 380 around the outside of the valve seat 460. The diameter of the valve seat 460 then decreases again at the distal end. A conduit is formed through the valve seat 460 to allow air flow through the valve seat 460 and is formed by a generally vertical orifice 470 and a pair of generally horizontal holes 480, 490. The generally vertical orifice 470 is formed in the valve seat 460 and extends into the valve seat 460 from the distal end of the valve seat 460. The generally horizontal hole 480 is formed in the valve seat 460 and extends from the vertical hole 470 out of the outer surface of the valve seat 460 whereby the hole 480 communicates with the vertical hole 470 and with the horizontal hole 380 in the carburetor body 610. The second generally horizontal hole 490 (shown in Figure 11 extending into the document ) is also formed in the valve seat 460 perpendicular to the horizontal hole 480 and also extends from the hole vertical 470 outwardly of the outer surface of the valve seat 460. The two perpendicular horizontal holes 480, 490 are used to facilitate the insertion of the valve seat 460 into the vertical hole 370 so alignment is not a concern. With the two horizontal perpendicular holes 480, 490 there is no problem with the orientation of the valve seat 460 when it is inserted into the hole 370, one or both horizontal holes 480, 490 will have the ability to communicate with the horizontal hole 380 in the body of the valve body. 610 carburetor. Alternatively, if alignment of the valve seat 460 is not a problematic issue, a single horizontal hole 480 could be used in the valve seat 460. The vertical bore 470 and the horizontal holes 480, 490 form the conduit through of the valve seat 460 allowing air to flow from the vertical hole 370 in the carburetor body 610 to the horizontal hole 380 in the carburetor body 610. The ball 400 is disposed within the vertical hole 370 at the distal end of the valve seat 460. The diameter of the ball 400 is slightly smaller than the diameter of the vertical hole 370 so the air is admitted to flow around the ball 400. When the ball 400 is in its lowest position, as shown in Figure 11, the ball sits against the distal end of the valve seat 460 preventing air flow in the orifice 370 within vertical hole 470 in the valve seat 460. As the ball 400 rises from its lowest position, as will be described in more detail below, air can flow around the ball 400 and into the vertical hole 470 in the valve seat 460. The mass of the ball 400 should be such that the ball will remain seated against the end distal valve seat 460 when the engine is at or below the ignition speed to start (the ignition speed to start is typically at 500 rpm but may vary depending on the engine). Additionally, the ball 400 should have a neutral frequency such that it will not come into resonance within the vertical hole 370 and will be disentangled from the distal end of the valve seat 460 by the vibrations produced by the motor at or below the engine ignition speed. . However, the natural frequency of the ball 400 should be such that between the starting speed of the motor and the maximum speed of the motor, the vibrations produced by the motor will cause the ball 400 to come into resonance within the vertical hole 370 and disengage of the distal end of the valve seat 460, which will allow air to flow around the ball 400 into the vertical hole 470 in the valve seat 460.

At normal engine operating speeds, the vibrations produced by the engine will cause the ball 400 to come into resonance with the hole 370 due to the natural frequency of the ball 400. This will cause the ball 400 to disengage from the distal end of the seat. valve 460, which will allow air from the orifice 702 to flow through the vertical hole 370, around the ball 400, and into the vertical hole 470 in the valve seat 460. This air will then flow through the vertical hole 470 and horizontal holes 480, 490 in the valve seat 460, inside the hole 380 in the carburetor body 610, and inside the nozzle 730. The air coming from the nozzle 730 then flows into the venturi 710 where it is mixed with the air from the intake orifice 700 and the fuel from the nozzle 730, as discussed above. The air from the intake port 700 and the air air passing through the enrichment system combine to provide the correct fuel / air mixture for proper engine performance and emissions. On the other hand, during the ignition of the engine, the weight of the ball 400 and the low rpm of the engine, and therefore the low vibration of the engine, keep the ball 400 seated against the distal end of the valve seat 460 thereby avoiding that air flows from the orifice 702 through the holes in the valve seat 460 and toward the nozzle 730. Therefore, during startup, a portion of air that would normally flow into the venturi 710 from the enrichment system is removed and only the air coming from the intake orifice 700 will flow to the venturi 710. This decreases the amount of air in the fuel / air mixture, which enriches the fuel / air mixture in the ignition thereby improving the engine's starting capacity. . This system provides the correct fuel enrichment during the engine start without the intervention of an operator and allows an adjustment to avoid an over or under enrichment. Fuel enrichment will typically occur until a time when the engine reaches idle speed (or at least the lower idle speed), which would indicate that the ignition was successful and that the engine would start. In the present embodiment, the motor 100 is a vertical axis motor with the capacity to provide 15-20 horsepower for use in a variety of garden machinery and lawn consumables such as lawnmowers. In alternative embodiments, the motor 100 may also be employed as a horizontal axis motor, may be designed to provide a greater or lesser amount of power, and / or be employed in a variety of different types of machines, for example, ventilators- for snow. In addition, the particular arrangement of the parts within the motor 100 may vary from what is shown and described above. For example, in an alternate embodiment, the cams 360 could be located above the gears 320 instead of below the gears. While the above specification illustrates and describes the preferred embodiments of this invention, it should be understood that the invention is not limited to the precise construction described herein. The invention may have other specific forms of embodiment without departing from the spirit or essential attributes of the invention. Accordingly, reference should be made to the following claims, rather than to the above specification, as an indication of the scope of the invention. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (20)

2. Having described the invention as above, the content of the following claims is claimed as property. A carburetor for an internal combustion engine, characterized in that it comprises: a body having a first end that holds an air filter, a second end that holds an intake port of a cylinder head, an intake orifice formed at the first end, a regulator orifice formed at the second end, a venturi formed between the intake orifice and regulator orifice interconnecting the intake orifice and the regulator orifice, and an injector conduit extending from the venturi through the body to supply fuel to the venturi; a fuel cube, which has walls that define an interior volume, attached to the body; a fuel enrichment system, sensitive to the vibration of the engine, having a duct formed in the body having an inlet communicating with the intake orifice and an outlet communicating with the injector duct, wherein the system Fuel enrichment reduces the flow of air through the duct when the engine is at a speed lower than the idle speed and increases the air flow through the duct when the engine is at speeds greater than the starting speed. A carburetor for an internal combustion engine according to claim 1, characterized in that it comprises an injector nozzle disposed within the injector conduit, wherein the outlet of the fuel enrichment system conduit communicates with the injector nozzle .
3. 3. A carburettor for an internal combustion engine according to claim 1, characterized in that it comprises a hub ventilation, formed in the body, that interconnects the intake orifice and the interior volume of the fuel hub, wherein the intake of the Fuel enrichment system duct communicates with bucket ventilation.
4. A carburetor for an internal combustion engine according to claim 3, characterized in that it comprises an injector nozzle inside the injector conduit, wherein the outlet of the fuel enrichment system conduit communicates with the injector nozzle.
5. 5. A carburetor for an internal combustion engine according to claims 1, 2, 3, or 4, characterized in that the fuel enrichment system comprises: a valve seat disposed within the conduit in the body, the valve seat It has a duct to allow the flow of air through the valve seat; and a ball disposed within the duct in the body, where the ball sits against the valve seat which locks the duct in the valve seat when the engine is at a speed lower than the starting speed and becomes dislodged of the valve seat and vibrates within the conduit in the body thereby unlocks the conduit in the valve seat and allows air to flow through the conduit in the valve seat when the engine is at speeds greater than the starting speed.
6. 6. A carburetor for an internal combustion engine according to claim 5, characterized in that: the conduit in the body is formed by a generally vertical orifice, which extends from a proximal end at the entrance of the enrichment system conduit of fuel through the body to a distal end communicating with the interior volume of the fuel hub, and a generally horizontal hole, which extends from a proximal end in the generally vertical hole to a distal end at the outlet of the conduit of the fuel enrichment system; the valve seat is fixed by pressure inside the distal end of the generally vertical hole, and the conduit in the valve seat allows the flow of air from the vertical hole towards the horizontal hole.
7. A carburetor for an internal combustion engine according to claim 6, characterized in that the conduit through the valve seat comprises: a generally vertical orifice communicating with the generally vertical orifice of the conduit and extending into the seat of the valve. valve; and a generally horizontal hole extending from the generally vertical hole in the valve seat to the generally horizontal hole in the conduit.
8. A carburetor for an internal combustion engine according to claim 7, characterized in that the conduit through the valve seat further comprises a second generally horizontal hole, perpendicular to the horizontal hole, extending from the generally vertical orifice in the Valve seat to the generally horizontal hole of the duct.
9. 9. An internal combustion engine having a carburetor that is held between an air filter and an intake port of a cylinder head, the carburetor is characterized in that it comprises: a body having a first end that holds the air filter. air, a second end that secures to the intake port, an intake orifice formed in the first end, a regulator orifice formed in the second end, a venturi formed between the intake orifice and the regulator orifice interconnecting the orifice inlet and regulator orifice, and an injector duct extending from the venturi through the body to supply fuel to the venturi; a fuel cube, which has walls that define an interior volume, attached to the body; a fuel enrichment system, sensitive to the vibration of the engine, having a duct formed in the body having an inlet communicating with the intake orifice and an outlet communicating with the injector duct, wherein the system Fuel enrichment reduces the flow of air through the conduit when the engine is at speeds lower than the starting speed and increases the flow of air through the conduit when the engine is at speeds greater than the starting speed.
10. 10. An internal combustion engine according to claim 9, characterized in that it comprises an injector nozzle disposed within the injector conduit, wherein the outlet of the fuel enrichment system conduit communicates with the injector nozzle.
11. An internal combustion engine according to claim 9, characterized in that it comprises a hub ventilation, formed in the body, which interconnects the intake orifice and the interior volume of the fuel hub, wherein the system duct inlet Fuel enrichment communicates with bucket ventilation.
12. 12. An internal combustion engine according to claim 11, characterized in that it comprises an injector nozzle inside the injector conduit, wherein the outlet of the fuel enrichment system conduit communicates with the injector nozzle.
13. 13. An internal combustion engine according to claims 9, 10, 11, or 12, characterized in that the fuel enrichment system comprises: a valve seat disposed within the conduit in the body, the valve seat has a duct to allow air flow through the valve seat; and a ball disposed within the duct in the body, where the ball sits against the valve seat which locks the duct in the valve seat when the engine is at a speed lower than the starting speed and becomes dislodged of the valve seat and vibrates within the conduit in the body thereby unlocks the conduit in the valve seat and allows air to flow through the conduit in the valve seat when the engine is at speeds greater than the starting speed.
14. An internal combustion engine according to claim 13, characterized in that: the duct in the body is formed by a generally vertical orifice, which extends from a proximal end at the inlet of the fuel enrichment system duct to through the body to a distal end communicating with the interior volume of the fuel hub, and a generally horizontal hole, which extends from a proximal end in the generally vertical hole to a distal end at the outlet of the system conduit. fuel enrichment; the valve seat is fixed by pressure within the distal end of the generally vertical hole, and the passage in the valve seat allows air to flow from the vertical hole to the horizontal hole.
15. 15. An internal combustion engine according to claim 14, characterized in that the conduit through the valve seat comprises: a generally vertical orifice communicating with the generally vertical orifice of the conduit and extending into the valve seat; and a generally horizontal hole extending from the generally vertical hole in the valve seat to the generally horizontal hole in the conduit.
16. 16. An internal combustion engine according to claim 15, characterized in that the conduit through the valve seat further comprises a second generally horizontal orifice, perpendicular to the horizontal orifice, extending from the generally vertical hole in the valve seat to the generally horizontal hole of the duct.
17. 17. A carburetor for an internal combustion engine, characterized in that it comprises: a throat having a hole extending through it from a first end within which combustion air is drawn to a second end through which a mixture of air / fuel leaves the throat; a fuel hub that has walls that define an interior volume; an injector conduit from the interior volume of the fuel hub to the throat orifice to supply a fuel flow from the interior volume of the fuel hub to the throat orifice to mix with the flow of air through the orifice; a fuel enrichment system in communication with the throat orifice, the fuel enrichment system has an air duct that supplies a flow of air to an injector duct at engine speeds above the starting speed in the When the engine is turned on, the device is sensitive to engine vibration at normal engine operating speeds to reduce air flow through the air duct to the injector duct above the ignition start speed of the engine.
18. 18. A carburetor for an internal combustion engine according to claim 17, characterized in that the air duct of the fuel enrichment device opens in the injector duct.
19. A carburetor for an internal combustion engine according to claim 17, characterized in that the fuel enrichment device has an element that opens an air valve to increase the flow or air through the air duct in response to the vibration of the engine at normal engine operating speeds above the starting speed at engine start.
20. 20. A carburetor for an internal combustion engine according to claim 19, characterized in that the element is a ball, and the ball vibrates at normal operating speeds of the engine above the starting speed at engine start to open the air valve.

    SUMMARY OF THE INVENTION

    A carburetor is described for a combustion engine having a body that holds at a first end to an air filter and at a second end to an intake port of a cylinder head. The body has an intake orifice formed at the first end that receives air from the air filter, a regulator orifice formed at the second end that provides a fuel / air mixture to the intake port, and a venturi formed between the air orifice. inlet and regulator orifice that receives air from the intake port, supplies fuel to form a fuel / air mixture, and supplies the air / fuel mixture to the regulator orifice. A hole is formed in the body of the venturi and receives a nozzle that communicates fuel to the venturi. A fuel enrichment system, which is sensitive to engine vibration, has a duct that communicates air from the intake port, through the duct, to the nozzle. A valve seat disposed within the conduit and also has a conduit to allow the flow of air therethrough. A ball is disposed within the fuel enrichment system conduit that sits against the valve seat when the engine is at speeds below that of the engine start to prevent passage of air through the valve seat. When the engine is at speeds above the engine start, the ball will come into resonance within the fuel enrichment system duct and will be disengaged from the valve seat, thereby allowing air flow around the ball and through the valve seat.