FUEL AND AIR CHARGE FORMING DEVICE

Abstract

A charge-forming device (10) for an internal combustion engine, comprising: a throttle body (18) having a throttle bore (20) with an inlet (22) through which air flows into the throttle bore (20) and an outlet (24) from which a fuel-air mixture exits the throttle bore (20), wherein the throttle bore (20) has a throat (32) between the inlet (22) and the outlet (24) and the throat (32) has a reduced flow area compared to the inlet (22) and / or the outlet (24); a throttle valve (36) having a valve head (38) which is received in the throat (32) of the throttle bore (20) and is movable with respect to the throttle body (18) between a first position and a second position, wherein the flow area between the valve head (38) and the throttle body (18) is larger when the valve head (38) is in the second position compared to the first position,wherein the device (10) further comprises an inlet fuel chamber (80) in which a supply of liquid fuel is received, and a fuel metering valve (180) arranged in a fuel circuit between the inlet fuel chamber (80) and the throttle bore (20), wherein the inlet fuel chamber (80) has an outlet (104) located directly above a region of the metering valve (180) with respect to the direction of gravity, and the fuel metering valve (180) comprises a solenoid having a wire coil (62) around a coil former (64) and an armature (68) received in a passage (181) in the coil former (64), and wherein the coil former (64) has one or more gaps (196) arranged, and the region of the surface (198) defining the passage (181) is reduced.

Description

REFERENCE TO RELATED REGISTRATIONS

[0001] This application claims the benefit of the preliminary US application filed on June 15, 2017, with serial number 62 / 519,908, the complete contents of which are incorporated herein by reference in their entirety. TECHNICAL AREA

[0002] The present disclosure relates generally to a fuel and air charge formation device such as can be used to provide a combustible fuel-air mixture to an engine. BACKGROUND

[0003] A variety of fuel injection throttle body configurations are known to supply a fuel-air mixture to an internal combustion engine to assist its operation, whereby a liquid gasoline fuel is injected into a main bore at a relatively high pressure, usually in the range of 6 to 40 psi and sometimes up to 80 psi or more above ambient air pressure, to facilitate the mixing or dispersing of the liquid fuel in the fuel-air mixture supplied to the engine.To control the flow rate of the fuel-air mixture to the engine, a throttle valve with a flat valve head is mounted in the main bore on a stem that rotates to move the valve head between an idle position, associated with low engine speed and / or low-load operation, and a wide-open or fully open position, associated with high engine speed and / or high-load operation. A fuel pump is connected to a pressure regulator and delivers liquid fuel at this high pressure to a fuel metering valve or fuel metering injector, which opens and closes to deliver the appropriate amount of fuel into the main bore for the current engine operating condition. The fuel metering valve is located downstream of the throttle body and near the engine's fuel inlet port or intake valve pocket. SUMMARY

[0004] In at least some implementations, a charge-forming device for an internal combustion engine comprises a throttle body and a throttle valve. The throttle body has a throttle bore with an inlet through which air flows into the throttle bore and an outlet through which a fuel-air mixture exits the throttle bore. The throttle bore has a throat or neck between the inlet and the outlet, and the throat has a reduced flow area compared to the inlet and / or the outlet. The throttle valve has a valve head that is received within the throat of the throttle bore and is movable relative to the throttle body between a first position and a second position, with the flow area between the valve head and the throttle body being larger when the valve head is in the second position compared to the first position.

[0005] In at least some implementations, the throttle bore includes a converging section between the inlet and the throat and a diverging section between the throat and the outlet, with the flow area of ​​the converging section decreasing in the direction from the inlet towards the throat, and the flow area of ​​the diverging section increasing in the direction from the throat towards the outlet.

[0006] In at least some implementations, at least two fuel outlets are open at one end towards the throat of the throttle bore and connected at the other end to a fuel supply through which fuel enters the throttle bore. In at least some implementations, at least one fuel outlet is located between the throttle valve head and the outlet when the throttle valve is in the first position, and at least one fuel outlet is located between the throttle valve head and the inlet when the throttle valve is in the first position. In at least some implementations, a fuel chamber is provided within the throttle valve body and in conjunction with the fuel outlets, as well as a vent passage formed in the throttle body and connected to the fuel chamber to provide an airflow into the fuel chamber.The fuel outlets can be formed in the throttle body or in a housing of a fuel metering valve connected to the throttle body.

[0007] In at least some implementations, a fuel metering valve is supported by the throttle body, and the fuel supply is defined by a fuel chamber open to the outlets. The fuel metering valve has an outlet that leads directly into the fuel chamber to supply fuel. The fuel chamber may be defined by a cavity within the throttle body, and the fuel metering valve is partially contained within the cavity and engages with it in a sealing manner. Alternatively, the fuel chamber may be defined within a housing connected to the throttle body, and the fuel metering valve is connected to and engages with this housing in a sealing manner.

[0008] In at least some implementations, an inlet fuel chamber is provided, which receives a supply of liquid fuel, and a fuel metering valve is arranged in a fuel circuit between the inlet fuel chamber and the throttle bore, wherein the inlet fuel chamber has an outlet located directly above a region of the metering valve with respect to the direction of gravity. In at least some implementations, the fuel metering valve is electrically actuated, and a housing of the fuel metering valve is in direct heat transfer relationship with fuel from the inlet fuel chamber. In at least some implementations, the fuel metering valve is supported by the throttle body or by a second body in which the inlet fuel chamber is defined.

[0009] In at least some implementations, the fuel metering valve comprises a solenoid having a wire coil around a coil body, and an armature received in a passage in the coil body, wherein the coil body has one or more gaps arranged, and the area of ​​the surface defining the passage is reduced.

[0010] In at least some implementations, a fuel metering valve comprises: a coil former that defines a passage and has one or more gaps in the surface of the coil former that defines the passage; a coil of wire around the coil former; and an armature that is received within the passage in the coil former and is movable from a first position to a second position with respect to the coil former when current is supplied to the wire coil.

[0011] The passage can have an axis, and the gaps can be defined by several axially extending slots. In at least some implementations, a housing is provided that covers the coil and has an inwardly extending end, wherein the coil body also has a fuel inlet, a fuel outlet, and a valve seat between the fuel inlet and the fuel outlet, and wherein the inwardly extending end of the housing is open toward the fuel inlet, so that at least some fuel flowing through the fuel inlet engages with the inwardly extending end of the housing.

[0012] In at least some implementations, a charge-forming device for an internal combustion engine comprises a throttle body, a throttle valve, an inlet fuel chamber, and a fuel metering valve. The throttle body has a throttle bore with an inlet through which air flows into the bore and an outlet through which a fuel-air mixture exits the bore. The throttle valve has a valve head that is accommodated within the throttle bore and is movable relative to the throttle body between a first position and a second position, with the flow area between the valve head and the throttle body being larger when the valve head is in the second position compared to the first position. The inlet fuel chamber receives a supply of liquid fuel.And the fuel metering valve is located in a fuel circuit between the inlet fuel chamber and the throttle bore, and the inlet fuel chamber has an outlet which, with respect to the direction of gravity, is located directly above a region of the metering valve.

[0013] In at least some implementations, a fuel outlet is provided, open at one end towards the throat of the throttle bore and connected at the other end to a fuel chamber located between the outlet of the fuel metering valve and the fuel outlet, with the fuel metering valve being supported by the throttle body. The fuel chamber may be defined by a cavity within the throttle body, and the fuel metering valve is partially contained within the cavity and engages with it in a sealing manner. Alternatively, the fuel chamber may be defined within a housing connected to the throttle body, and the fuel metering valve is connected to and engages with the housing in a sealing manner.

[0014] The various features set out in the summary can be used in different combinations, so that certain embodiments may include all or fewer than all of the complementary or non-mutually exclusive features set out above and described in more detail below. List of characters

[0015] The following detailed description of certain embodiments and the best operating mode is set out with reference to the accompanying drawings, in which: Fig. 1 a perspective view of a throttle body arrangement comprising a throttle body with a throttle valve, a metering valve which controls at least part of the fuel flow in the arrangement, and a fuel vapor separator; Fig. 2 is a fragmentary sectional view of the throttle body arrangement; Fig. Figure 3 is a fragmentary sectional view of the throttle body assembly, showing the throttle valve and a throttle bore of the throttle body; Fig. Figure 4 is a fragmentary perspective sectional view of the throttle body arrangement; Fig. Figure 5 is a fragmentary sectional view of the throttle body assembly, showing the metering valve connected to the throttle body; Fig. Figure 6 is a fragmentary sectional view of the throttle body arrangement, showing an alternative metering valve arrangement; Fig. Figure 7 is a fragmentary sectional view of the throttle body arrangement, showing an alternative metering valve arrangement; Fig. Figure 8 is a fragmentary perspective view showing a vapor separation chamber with a cover and other components removed to show a fluid connection linking the separation chamber to the metering valve; Fig. Figure 9 is a diagram of an inlet pressure signal and illustrates a control window for actuating the metering valve; Fig. Figure 10 is a diagram showing the inlet pressure signal and a current to the metering valve; Fig. Figure 11 is a perspective view of a solenoid-type metering valve that can be used with the throttle body arrangement. Fig. Figure 12 is a perspective view of a coil former of the in Fig. 11 valve shown; Fig. 13 is a sectional view of the in Fig. 11 valve shown; and Fig. Figure 14 is a sectional view of a coil former with one or more gaps formed in an inner surface of the coil former. DETAILED DESCRIPTION

[0016] With closer reference to the drawings, the Fig. 1 and Fig. 2 a charge-forming device 10 , which supplies a combustible fuel-air mixture to an internal combustion engine to assist the engine's operation. The charge-forming device 10 It can be used on a two-stroke or four-stroke internal combustion engine and includes a throttle body assembly. 10 , from the air and fuel for delivery to the engine.

[0017] The arrangement 10 includes a throttle body 18 , which is a main bore, sometimes also a throttle bore 20 called, with an entrance 22 , through which air enters the throttle bore 20 is recorded, and an outlet 24 has a feature that is connected to the engine or otherwise related to it (e.g., to an intake manifold). The intake 22It can, if desired, draw in air from an air filter (not shown), and this air can be mixed with fuel supplied by a fuel metering valve. 28 is provided by the throttle body 18 The fuel-air mixture is supplied to a combustion chamber or piston cylinder of the engine during successive intervals of a piston cycle. In a four-stroke engine application, as shown, the fluid may flow through an intake valve and directly into the piston cylinder. Alternatively, in a two-stroke engine application, air typically flows through the crankcase (not shown) before entering the combustion chamber area of ​​the piston cylinder through a port or opening in the cylinder wall, which is intermittently opened by the reciprocating piston.

[0018] The throttle bore 20can have any desired shape, including (but not limited to) a cylinder with a generally constant diameter or a Venturi shape, as in the Fig. 3 and Fig. 4 shown. In the example with the Venturi shape, the inlet leads 22 to a tapered converging area 30 , where the inner diameter or flow area of ​​the bore 20 decreases and leads to a neck or throat 32 with a reduced diameter. In the area of ​​the throat. 32 can the throttle bore 20 exhibit a minimum flow area, which may be defined by the area of ​​the bore that has the smallest cross-sectional area perpendicular to an axis or centerline 33 the throttle bore. The throat 32 leads to a tapered, diverging area 34 , where the inner diameter or flow area of ​​the bore 20in relation to the throat. The diverging area is located between the throat. 32 and the outlet 24 The converging area 30 can cause an increase in the flow velocity of air into the throat? 32 (relative to the inlet) cause a pressure drop in the throat area 32 generate or amplify. In at least some implementations, the throttle body can 18 be cast from a suitable metal and have a throttle bore 20 can be defined within the body when the body is formed and / or further processing (e.g. machining) can be carried out to provide a desired shape of the throttle bore.

[0019] With reference to Fig. 1-5 the airflow rate through the throttle bore 20 and into the engine through a throttle valve 36controlled. In at least some implementations, the throttle valve includes 36 a head 38 , which may have a flat plate located in the throttle bore 20 arranged and with a rotating throttle valve stem 40 is connected. The shaft 40 extends through a shaft bore 42 , which the throttle bore 20 cuts and can generally run perpendicular to it. The throttle valve 36 can be from an actuator 44 driven or moved between an idle position in which the head 38 essentially the airflow through the throttle bore 20 blocked, and a fully or widely open position in which the head 38 the least restriction of airflow through the throttle bore 20 offers. In one example, the actuator can 44 an electrically driven motor 46 ( Fig. 2) be the one who is connected to the throttle valve stem 40 is connected to rotate the shaft and thus the valve head 38 within the throttle bore 20 to rotate. In another example, the actuator can 44 have a mechanical connection, such as a lever attached to the throttle valve stem 40 is attached, to which a Bowden cable can be connected to the shaft. 40 to rotate manually as desired.

[0020] The fuel metering valve 28 ( Fig. 2 and Fig. 5) may have an inlet 50 , to which fuel is supplied, a valve element 52 (e.g. a valve head) that controls the fuel flow rate, and an outlet 54 downstream of the valve element 52 To activate and move the valve element 52 To control the fuel metering valve 28an electrically driven actuator 56 , such as (but not limited to) a solenoid, or be associated with one. Among other things, the solenoid can 56 include an outer casing 58 , a coil 62 , which are located inside the housing 58 recorded coil former 64 is wound, an electrical connector 66 , which is arranged to be connected to a power source to power the coil 62 to selectively supply power, and an anchor 68 , which is movable within the coil body 64 It is designed to move back and forth between extended and retracted positions. The valve element 52 can from the anchor 68 relative to a valve seat 70 carried or otherwise moved, whereby the valve seat 70 within the solenoid 56 and / or the throttling body 18can be defined. If the anchor 68 when the valve element is in its retracted position 52 removed or from the valve seat 70 Spacing is maintained, allowing fuel to flow through the valve seat. When the armature... 68 when in its extended position, the valve element 52 against the valve seat 70 The solenoid is designed to be closed or to rest on the valve seat to prevent or stop fuel flow through it. 56 can be identified according to the US patent application using the serial number 14 / 896 ,764 be constructed, the revelation of which is included herein in its entirety. The outlet 54 can be centrally or generally coaxial to the valve seat 70 be arranged, and an entrance 50 can extend radially outwards from the outlet 54They should be spaced apart and generally radially oriented. Of course, other metering valves, including but not limited to various solenoid valves or commercially available fuel injectors, can also be used if desired for a particular application.

[0021] Fuel can flow from a fuel source to the metering valve inlet. 50 be supplied, and when the valve element 52 at the valve seat 70 If it is not closed, fuel can pass through the valve seat and the metering valve outlet. 54 and to the throttle bore 20 The fuel flows to be mixed with the air flowing through it and delivered to the engine as a fuel-air mixture. The fuel source can be controlled by the metering valve. 28 Supply fuel at a desired pressure. In at least some implementations, the pressure can be either ambient pressure or atmospheric pressure in general.

[0022] To the metering valve inlet 50 To supply fuel, the throttle body 18 an inlet fuel chamber 80 ( Fig. 2 and Fig. 8) have a throttle body assembly into which fuel is drawn from a fuel supply, such as a fuel tank. The throttle body assembly 10 can a fuel inlet 84 ( Fig. 1 and Fig. 2) exhibit, which leads to the inlet fuel chamber 80 This leads to the following: In a system where the fuel pressure generally corresponds to atmospheric pressure, the fuel flow can enter the inlet fuel chamber by means of gravity. 80 be directed. In at least some implementations, the inlet fuel chamber can be 80 through a vent 82 and a valve arrangement 86 (a simplified form of this is in Fig. (2 shown) at or near atmospheric pressure. The valve arrangement86 can a valve 88 include and can include a valve seat 90 exhibit or be associated with it, so that the valve 88 selectively with the valve seat 90 The valve can be engaged to prevent or stop the fluid flow through the valve seat, as described in more detail below. 88 can be used with an actuator 92 be connected, that the valve 88 relative to the valve seat 90 moved, as will be explained in more detail below. The ventilation 82 It can be connected to the engine intake manifold, to a carbon canister / air purifier to reduce evaporative emissions, or elsewhere (e.g., via a line) as desired, as long as the desired pressure is maintained within the intake fuel chamber. 80 is reached during operation. The fuel level within the intake fuel chamber. 80can provide a pressure level or pressure of the fuel that passes through the metering valve when the metering valve is open. 28 which can flow, supplementing the fuel flow that is generated by a sub-atmospheric pressure signal in the throttle bore. 20 is caused and is associated with the fuel when the metering valve is open, as described in more detail below.

[0023] To achieve a desired fuel level in the intake fuel chamber 80 to maintain the valve 88 relative to the valve seat 90 through the actuator 92 (e.g. a float in the illustrated example) moves, which is in the inlet fuel chamber 80 is absorbed and reacts to the fuel level in the intake fuel chamber. The float 92 can float and swivel in the fuel with the throttle body 18 be connected and the valve 88can with the swimmer 92 be connected to movement when the float moves in response to changes in the fuel level within the inlet fuel chamber 80 moved. When a desired maximum fuel level is reached in the intake fuel chamber. 80 The swimmer was present. 92 moved into a position in the inlet fuel chamber where the valve 88 The valve seat is engaged and closed. 90 , which controls the fuel intake 84 closes and allows another fuel flow into the intake fuel chamber 80 This prevents fuel from escaping the intake fuel chamber. 80 outlet (e.g. to the throttle bore) 20 through the metering valve 28 ), the swimmer moves 92 in response to the lower fuel level in the intake fuel chamber, and thereby moves the valve. 88 from the valve seat 90away, so that the fuel inlet 84 is open again. When the fuel inlet 84 When it is open, additional fuel flows into the intake fuel chamber. 80 , until a maximum fill level is reached and the fuel inlet 84 will be closed again.

[0024] The intake fuel chamber 80 It can also be used to separate liquid fuel from gaseous fuel vapor and air. Liquid fuel will settle at the bottom of the inlet fuel chamber. 80 settle and the fuel vapor and air rise in the inlet fuel chamber, where the fuel vapor and air pass through the vent. 82 can escape from the intake fuel chamber (and thus be directed into the intake manifold and then into an engine combustion chamber).

[0025] The intake fuel chamber 80 can at least partially pass through the throttle body 18be defined, for example, by a recess formed in the throttle body and a cover supported by the throttle body 98 Alternatively, as in the Fig. 1, Fig. 2 and Fig. As shown in 8, the throttle body arrangement can be 10 a second case or body 100 include the one connected to the throttle body 18 is connected and the fuel chamber 80 with the lid 98 defined partially or completely on the second body. In the example shown, the second body comprises 100 a cavity 102 , which is the fuel chamber 80 defined and the one from the throttle body 18 separated and completely within the second body 100 is defined. An outlet 104 the inlet fuel chamber 80 leads to the entrance 50 of the metering valve. The metering valve 28 can from the second body100 in at least some implementations, for example by being placed in a bore or a second cavity 106 ( Fig. 2 and Fig. 5) is taken up, which is in the second body 100 is formed. The second cavity 106 and the fuel chamber 80 are through the outlet 104 connected to each other. So that it's connected to the metering valve. 28 Fuel is available at all times when the fuel is within the intake fuel chamber. 80 The outlet is located 104 In at least some implementations, it will be an open passage without any intermediate valve. The outlet 104 can originate from the floor or a lower area of ​​the intake fuel chamber 80 extend so that the fuel reaches the metering valve at atmospheric pressure 28 It can flow. A filter or sieve can be attached to or placed in the outlet if desired.104 This may be provided. One or more other filters may be provided instead or additionally at another point in the fuel system in general and in the throttle body as desired.

[0026] The open outlet 104 may also allow any air or fuel vapor that flows downstream from the fuel chamber to enter. 80 e.g. in the outlet 104 or at the metering valve 28 , is generated, into the fuel chamber 80 flows. As mentioned above, the gaseous matter can then escape from the fuel chamber. 80 It needs to be bled. If the fuel metering valve 28 If the valve is electrically operated, for example by a solenoid, it may be necessary to use it if... 28Heat is generated, and this heat can cause some of the fuel that comes into contact with the metering valve / solenoid to evaporate. If these vapors are not vented, the fuel flow from the metering valve can be restricted. 28 to the throttle bore 20 less constant than desired, as vapor bubbles enter the liquid fuel stream. In at least some implementations, such as in Fig. As shown in 2, the outlet is located 104 the fuel chamber 80 in connection with admission 50 of the metering valve and with an area of ​​the solenoid housing 58 , that the coil 62 of the solenoid. In the example shown, the metering valve inlet is 50 axially from the end of the coil 62 , which leads to admission 50 nearest, spaced apart, and the outlet 104 overlaps and spans the area between the valve inlet 50and the end of the coil 62 Therefore, heat can escape from the coil. 62 transferred to the fuel to lower the temperature of the solenoid, and any fuel vapor produced in the process can be vented as described above.

[0027] When using the throttle body arrangement 10 is a fuel circuit between the intake fuel chamber 80 and the throttle bore 20 defined. Fuel is supplied to the intake fuel chamber. 80 held as described above and thus in the outlet 104 and in the cavity 106 , in which the metering valve 28 is absorbed (and possibly within a region of the metering valve upstream of the valve seat) 70 ). If the metering valve 28 When closed, no or essentially no fuel flows through the valve seat. 70and therefore no fuel reaches the outlet of the metering valve. 54 or to the throttle bore 20 To supply fuel to the engine, the metering valve is used. 28 opened and fuel flows into the throttle bore. 20 , is mixed with air and delivered to the engine as a fuel-air mixture.

[0028] To reduce the distance the fuel has to travel to reach the throttle bore 20 To achieve this, or for other reasons, the metering valve outlet may 54 connected to a cavity or pocket that forms at least part of a fuel chamber 110 ( Fig. 5) defined, which is in the throttle body 18 is formed within 20 mm of the throttle bore. The fuel chamber 110 can be used with the throttle bore 20 through one or more fuel outlets 112 are connected. The fuel outlets 112These can be simple passages or bores in the throttle body 18 between the throttle bore 20 and the fuel chamber 110 Nozzles, including those with a desired orifice size, which are formed in an insert, can be inserted into the throttle body. The outlets 112 can occur in the area of ​​the Venturic throat 32 provided for, whereby within the throttle bore 20 a maximum flow velocity and a maximum pressure drop can be achieved in order to operate at a relatively small pressure difference (pressure difference between the fuel chamber) 80 and the throttle bore 20 ) to generate an increased fluid flow into the throttle orifice. The increased pressure signal and the resulting fluid flow rate can also cause the mixing of liquid fuel with the fluid passing through the throttle orifice. 20improve the flow of air to provide the engine with a more consistent fuel mixture and improve combustion in the engine.

[0029] Furthermore, the throttle valve can 36 also in the throttle bore throat 32 This is planned. This reduces the flow area in the throat. 32 further and thereby increases the flow velocity. When the throttle valve 36 is in a first or idle position, as in the Fig. As shown in 3-7, the valve head is 38 almost perpendicular to the axis 33 the throttle bore 20 arranged and between the valve head 38 and the throttle body 18 A minimum flow range is provided. An additional fluid flow can be introduced through one or more openings in the valve head, if desired. 38 be provided. In at least some implementations, there is at least one fuel outlet.112 upstream of the throttle valve head 38 , when the throttle valve 36 is in the idle position, i.e., between the throttle bore inlet 22 and the valve head 38 , when the throttle valve 36 in its idle position. In at least some implementations, at least one fuel outlet is present. 112 downstream of the throttle valve head 38 arranged when the throttle valve 36 is in the idle position, i.e., between the throttle bore outlet 24 and the valve head 38 , when the throttle valve 36 in its idle position. In the implementation shown, there are two fuel outlets. 112 upstream and a fuel outlet 112 downstream of the throttle valve 36arranged when it is in the idle position. In at least some implementations, the fuel outlets are 112 through separate, spaced-apart bores in the throttle body 18 defined, which is located between the throttle bore 20 and the fuel chamber 110 extend and are essentially perpendicular to the axis 33 the throttle bore 20 They can be essentially parallel to the direction of movement of the metering valve. 28 between its open and closed positions and which have a length of less than 20 mm. As used herein, "essentially" means a range of 10 degrees of the specified orientation (e.g., 10 degrees perpendicular or parallel to the specified reference).

[0030] Furthermore, as in the Fig. 4-7 shows an air passage 114 in the throttle body 18 be provided for. The air passage 114can be affected by the throttle bore 20 separate entrance 116 and an outlet 118 exhibiting, which is connected to the fuel chamber 110 is connected, which is downstream of the metering valve 28 and upstream from the fuel outlets 112 up to the throttle bore 20 is arranged. In the example shown, the air passage leads to 114 from the admitting end 22 of the throttling body 18 and to the fuel chamber 110 .

[0031] As in the Fig. As shown in 4-7, the air intake passage can be viewed 114 an insert or nozzle 120 with a passage or mouth 122 The nozzle should be of a desired size. 120 can be a separate body that is press-fitted into the passage 114 is arranged or otherwise installed therein, and air can pass through the mouth. 122flow before they reach the metering valve 28 The flow area of ​​passages downstream of the nozzle is reached. 120 Its dimensions can be larger than the minimum flow area of ​​the nozzle, so that the nozzle represents the maximum limitation of the airflow through the intake passage. 114 offers. Instead of or in addition to the nozzle 120 can enter the throttle body 18 A passage of suitable size must be drilled or otherwise formed to maximize the limitation of airflow through the intake passage. 114 to define the use of a nozzle 120 This can facilitate the use of a common throttle body design with multiple engines or in different engine applications, where different airflow rates may be required. To achieve these different flow rates, different nozzles can be used. 120 with mouths 122with different effective flow ranges in the throttle bodies 18 can be used, while the rest of the throttle body can be the same. Furthermore, the throttle body can be modified in various ways. 18 in addition to or instead of using a nozzle 120 Passages of varying diameters are formed to achieve a similar effect. The insert or nozzle may also include, carry, or be associated with a check valve that allows airflow to the fuel chamber. 110 allows, but restricts the fluid flow from the air passage inlet 116 in the opposite direction to prevent fuel from leaking out of the intake passage 114 (e.g., if fuel remains in the fuel chamber after the engine has stopped running) to prevent or suppress this. Furthermore, in some applications, the air intake passage may be affected. 114They must be covered or blocked to prevent airflow.

[0032] In the Fig. 2 and Fig. The example shown in section 5 uses the metering valve. 28 from the second case 100 worn. The second body 100 includes a lead 130 or an end that is inside a cavity 131 in the throttle body 18 The fuel outlet is enclosed and sealed (e.g., by an O-ring). 54 The metering valve leads to a passage 132 , which is distinguished by its lead 130 extends and with the fuel chamber 110 is connected to the cavity 131 between the end of the lead 130 and the throttle body 18 is defined, in particular the wall of the throttle body 18 , which are the fuel outlets 112 includes those that lead to the throttle bore 20This leads to fuel being drawn from the metering valve. 28 and air from the air passage 114 inside the fuel chamber 110 upstream of the throttle bore 20 combined, and this mixture then flows through the fuel outlets. 112 and is carried through the throttle bore 20 The flowing air is mixed to provide a mixture of fuel dispersed in air. The air passage 114 opens independently and at a distance from the lead 130 into the fuel chamber 110 , although the projection could have an opening, passage or other gap that defines part of the air passage, if desired.

[0033] In the Fig. The example shown in section 6 uses the metering valve. 28 from the throttle body 18 in a cavity 134 worn in the choking body 18is trained, and the metering valve 28 is from the second body 100 separated. Between the throttle body 18 and the fuel inlet 50 and the fuel outlet 54 of the metering valve 28 Seals are provided to prevent fuel from leaking out of the throttle body. 18 around the metering valve. In this example, the fuel chamber 110 defined in the cavity 131 , which is open to the cavity 134 and a countersink hole in the cavity 134 It can be located between the metering valve outlet. 54 and the throttle body 18 , in particular the wall of the throttle body 18 , which are the fuel outlets 112 features which lead to the throttle bore 20 lead to the fuel outlets. 112 can be conveniently used with the cavity 134 and the countersink 131are aligned towards the outside of the throttle body 118 are open to form the fuel outlets 112 to facilitate the airflow directly in the throttle body in at least some implementations. 114 It opens independently and at a distance from the metering valve. 28 into the fuel chamber 110 , although the metering valve (e.g., a housing thereof) could have an opening, passage, or other gap that defines part of the air passage, if desired.

[0034] In the Fig. The example shown in section 7 is the metering valve. 28 from a case 136 with an area that is located in a cavity 134 in the throttle body 18 is recorded. The casing 136 could be a second body (like the second body) 100 ) be, or as in Fig. 7 shows a body that is removed before assembly of the throttle body 18 and the second body 100 is separated. The housing 136 can open area 138 exhibiting a structure that defines the fuel chamber in whole or in part. The housing 136 It can also be an opening or a passage 140 exhibiting the air passage 114 is connected and / or defines part of the air passage to allow air into the fuel chamber 138 from the air passage 114 to record the nozzle 120 or another flow regulator can be attached to the housing 136 or from the throttle body 18 as previously described, to direct the current from the air duct 114 into the fuel chamber 138 to control. Finally, the housing can 136 a front wall 142 have openings that include the fuel outlets 112define, by the air and fuel from the fuel chamber 138 into the throttle bore 20 flow. Thus, the front wall can 142 of the case 136 into the throttle bore 20 extend into it or define a part of it. An outer surface of the front wall 142 can be shaped in such a way that it achieves a desired shape and size of the throttle bore 20 in the area of ​​the fuel outlets 112 and the throttle valve provides a way to improve fluid flow through the throttle bore. This modular design allows the fuel chamber to be customized. 138 , the air passage 114 (e.g. the nozzle) and the size of the fuel outlet 112 , the orientation and general arrangement can be changed by simply replacing the housing 136 to change the metering valve 28 carries. Therefore, the same choking body can 18 with various metering valves28 , and various arrangements of the fuel chamber 138 , of the air passage 114 and the fuel outlet 112 can be used. Furthermore, other features and components, such as a fuel drain, can be used. 146 and a drain valve 148 ( Fig. 1 and Fig. 4), in the second body 100 be absorbed or carried by it. The fuel drain 146 Can the fuel drain from the intake chamber 80 to enable the repair of the throttle body 18 to facilitate without fuel leakage (e.g. when removing the metering valve) 28 ) or to remove fuel from the intake chamber 80 to remove when the engine is not running, in order to reduce fuel vapor emissions from the throttle body assembly 10 to reduce. Instead of being part of the second body 100 to be, could be the fuel drain 146 from the throttle body18 be worn.

[0035] The timing and duration of the opening and closing of the metering valve can be controlled by a suitable microprocessor or other control unit. The timing of the fuel flow (e.g., injection), or when the metering valve... 28 If opened during an engine cycle, the pressure signal at the outlet can be 54 and thus the differential pressure across the metering valve 28 and the resulting fuel flow rate into the throttle bore 20 They change. In addition, both the magnitude of the engine pressure signal and the airflow rate through the throttle valve change. 36 There is a significant difference between the engine running at idle and the engine running with the throttle wide open. In summary, the duration during which the metering valve is open has a significant effect. 28The amount of fuel entering the throttle bore depends on the amount of fuel that is opened for a specific fuel flow rate. 20 flows.

[0036] In general, the engine pressure signal within the throttle bore indicates 20 at the fuel outlet 54 The pressure signal is higher at idle than with the throttle wide open. On the other hand, the pressure signal at the fuel outlet is... 54 , which is caused by the airflow through the throttle bore 20 A larger amount is generated when the throttle is wide open than at idle.

[0037] Fig. Figure 9 illustrates a representative pressure signal that can be transmitted to the throttle bore, such as the pressure at the engine intake manifold. In the example shown, a vacuum or subatmospheric pressure is created in the combustion chamber and intake manifold when the engine piston is at top dead center (TDC) (indicated by the vertical lines). 150 ) and begins to decrease towards a ground position. This subatmospheric pressure is measured via the throttle bore. 20 to the fuel outlets 112 It transmits and also draws in air through the throttle orifice. The airflow through the throttle orifice 20 and especially the throat 32 With a reduced flow range (reduced flow range compared to the inlet and / or outlet of the throttle bore), a pressure drop is created across the fuel outlets. 112, which also includes fuel from the fuel chamber 80 through the fuel outlets.

[0038] In at least some implementations, the fuel flow is located in the throttle body assembly. 10 At very low pressure, and which can occur without a pressure-reducing fuel pump, the fuel flow rate to the throttle bore can be affected. 20 be lower than in higher-pressure fuel systems. Accordingly, in order to utilize the full pressure signal from the intake manifold, the metering valve is used in at least some implementations. 28 The metering valve opens precisely when the intake manifold pressure begins to drop during an engine intake stroke (e.g., at or shortly after TDC). Furthermore, the valve can be held in its open position until the subatmospheric pressure reaches its maximum value, which is generally at point 152 will be displayed. At a later time after this point 152can the metering valve 28 The metering valve closes depending on the engine's fuel demand at that time (e.g., changes in fuel demand due to changes in engine speed and load). If comparatively more fuel is needed, the metering valve closes. 28 The metering valve is held open longer, and when comparatively less fuel is needed, it closes earlier. When the intake or suction pressure is at or near the nominal value shown at 154, the metering valve should... 28 The metering valve must be closed to prevent overpressure from negatively affecting the fuel flow through it. This can occur either when the piston reaches TDC again, or shortly before, and before the piston begins its subsequent descent during an exhaust stroke of the engine (in a two-stroke engine). Thus, the metering valve can 28controlled during the full pressure signal that is present during the engine's intake stroke. As in Fig. As shown in Figure 9, the pressure signal can vary as the piston approaches the exhaust stroke near TDC and the fuel mixture is compressed within the combustion chamber, but the metering valve can remain open during this time if fuel flow is required.

[0039] Fig. Figure 10 illustrates an example where the intake pressure signal is represented by the line 156 The engine position is represented by the line. 158 depicted (where the peaks 160 (indicating the passing of a magnet associated with a flywheel or other component that rotates with the engine) and the state of the metering valve is indicated by the line 162 depicted, which shows the current used to actuate the metering valve. 28 is provided. In this example, the metering valve was used.28 Current is supplied after the motor position signal (e.g., the passing magnet) is detected and shortly thereafter the intake pressure begins to drop. The current then flows to the metering valve. 28 The process was interrupted so that the valve could then close. Here, the metering valve was... 28 closed before the intake signal 156 reached its maximum value, which was the throttle bore 20 It would supply a relatively small amount of fuel, as may be required to support engine operation at low speeds and loads. At higher engine speeds or loads, the metering valve flow would be provided for a longer period to utilize more of the intake pressure pulse and cause more fuel to flow into the throttle orifice.

[0040] The relative engine operating state, for example, the engine position relative to TDC and whether the engine is in the intake or exhaust stroke, can be determined in various ways, including by an engine speed sensor. The speed sensor can be an inductive sensor (VR sensor; variable reluctance sensor) that responds to the passage of a magnet on the engine flywheel through the sensor, or otherwise, as is known in the prior art. The engine's fuel demand can be determined in at least some implementations as a function of the speed sensor and / or a throttle valve position sensor.

[0041] In the Fig. The example shown in section 24 is the throttle valve position sensor. 164 provided so that the system can determine the current rotational position of the throttle valve 36 can determine. The throttle valve position sensor 164 can a magnet 166 include the one from the throttle valve stem40 is worn (e.g. by someone attached to the shaft) 40 attached carrier 167 ) and a magnetically reacting sensor 168 , which is from a circuit board 170 is worn. The circuit board 170 , the sensor 168 and one end of the throttle valve stem 40 , on which the magnet 166 is recorded, and can be taken from one with the throttle body 18 connected housing 172 It should be covered. The throttle valve position sensor 164 It can be of any suitable type, and although it is depicted as a contactless, magnetic sensor, it can be a contact-based sensor (e.g., with variable resistance or a potentiometer). The circuit board 170 can be a controller or a processor 174include, which is used to determine the throttle valve position (e.g., idle, fully or wide open, or any position or degree of opening between idle and wide open), or it can be the output of the sensor. 168 connect to a remotely located controller. Furthermore, if the circuit board 170 a control 174 The same control system can also be used to control the actuation of the metering valve. 28 be used.

[0042] In the example shown, the throttle valve position sensor is located 164 at one end of the throttle valve stem 40 and the throttle valve actuator 44 (e.g. the engine) 46 or the valve lever) is located at the other end. In such an arrangement, both ends of the throttle valve can be 36 from the outside of the throttle body 18be accessible and have components attached in such a way that a holder for the throttle valve stem 40 is located between the ends of the shaft. In the Fig. 3 and Fig. In the 4 implementations shown, the holder includes a C-clip. 176 or an E-clip that partially fits into a groove 178 is used, which extends to the extent of the throttle valve stem 40 is trained. The holder 176 prevents or inhibits the axial movement of the shaft 40 in one direction, and another holder or carrier 167 on the opposite side of the throttle bore 20 can the axial movement of the shaft 40 to prevent or block flow in the opposite direction. Other arrangements of a throttle valve 36 can be used, including an arrangement in which both the position sensor 164 as well as the actuator44 at the same end of the throttle valve stem 40 condition.

[0043] In at least some implementations, a stepper motor can be used. 46 to operate the throttle valve 36 can be used and the rotational position of the stepper motor can be used to determine the position of the throttle valve. 36 can be used if desired. For example, a controller can be used. 174 , which are used to operate the stepper motor 46 It is used to track the rotational position of the stepper motor, and this can be used to determine the position of the throttle valve. 36 can be used. With a stepper motor 46 , which is the throttle valve 36 Even if activated, it may still be desirable to have a separate throttle valve position sensor. 164 to install in order to provide feedback for use when actuating the throttle valve. 36to provide improved control and position determination of the throttle valve.

[0044] A metering valve 180 , the one with the throttle body 18 can be used in the Fig. 11-13 shown. As in Fig. As best illustrated in 13, the metering valve can be 180 have an outer shell or casing 58 , that the coil 62 surrounds, as well as the coil body 64 , on which the coil 62 is recorded, and the anchor 68 , which in one pass 181 in the coil body relative to the coil body 64 is moved by the magnetic field produced by the coil 62 is generated when current is applied. In the example shown, the coil body extends 64 axially outwards from one end 182 of the case 58 and defines a valve seat 70 , which can be engaged with the anchor 68or a valve driven by the armature or a valve head supported by the armature 52 The valve seat 70 is located upstream of an outlet opening 183 (at the outlet) 54 ) at one end 184 of the coil body 64 At its other end 186 can the coil former 64 electrical connections 66 (which, according to the drawings, may be male flat plug connectors) with which the coil 62 is connected in a known manner. An anchor stop 190 can within the coil former passage 181 are recorded and arranged in such a way that the movement of the anchor 68 from the valve seat 70 The path is limited. A preload element, such as a coil spring, for example. 192 , can be between the anchor 68 and the anchor stop 190 must be positioned so that the anchor yields towards the valve seat.70 to pre-tension so that the metering valve 28 is closed when the coil 62 No energy is supplied.

[0045] The coil former 64 It also defines a fuel inlet. 50 for the metering valve 28 , which passes through one or more openings in the area of ​​the coil body 64 is defined as being separate from the housing 58 extends outwards. The openings 50 can extend radially through the coil body 64 extend and the fuel thus flows from outside the coil body. 64 and through the openings 50 into the passage 181 within the coil body, in which the armature is located 68 and / or move the valve. If the anchor 68 and / or if the valve is in an open position, fuel can pass through the valve seat. 70 and from outlet 54 / the outlet opening 183flow. When the anchor 68 and / or the valve is in a closed position, the flow of fuel through the valve seat will be restricted. 70 prevented or prevented. As above in relation to the Fig. 2 and Fig. As mentioned in point 8, the entrance(s) can be 50 in the coil body 64 from a point on or within 2 mm of the adjacent end of the coil former 62 extend. In the implementation shown, the housing covers 58 the coil 62 from and includes an end extending radially inwards 182 , which provides an edge or border that leads to the inlet(s). 50 is adjacent and can be brought into contact with at least some fuel from the inlet fuel chamber 80 to the entrances 50 flows. That is, between the inlet fuel chamber. 80 and the end 182of the case 58 No fluid seal is provided. Part of the coil 62 The generated heat is transferred to the casing 58 and transferred from the casing to the fuel. This can damage the casing. 58 and the metering valve 28 Generally, cooling occurs, and any vapor that arises in the fuel as a result can be removed from the fuel chamber as described above. 80 It can be vented. Furthermore, the inlet(s) can be... 50 directly below the outlet of the inlet fuel chamber 80 to be installed, whereby "below" in this case means below and in line with the direction of gravity. The one or more inlets. 50 They can have an axial length (measurement in the direction of the axis of the metering valve) between 0.1 mm and 6 mm.

[0046] As in Fig. As shown in 14, the surface area of ​​the coil body can be reduced. 64, the one with the anchor 68 It can be intervened, gaps 196 within the inner surface 198 of the coil body, at least within the area of ​​the passage 181 , in which the anchor 68 is recorded. In which in Fig. The 14 examples shown are located on the inner surface 198 of the coil body 64 one or more axially extending slots 196 formed. The slits 196 can extend entirely over the axial length or over a range of the axial length of the coil passage 181 extend. The slots 196 They can have any desired radial depth and can be widely spaced from each other to create contact areas with reduced surface area between the slots. 196 provide. The anchor 68 can be connected to one or more contact areas (areas of the inner surface) 198between the slots) engage to allow guided movement between the open and closed positions of the metering valve 28 to enable the reduced surface area of ​​potential intervention between the anchor. 68 and the coil former 64 This can reduce the friction between them and increase the movement rate of the armature to improve the response time of the metering valve.

[0047] The forms of the invention disclosed herein represent currently preferred embodiments, and many other forms and embodiments are possible. It is not intended to mention here all possible equivalent forms or branches of the invention. It is understood that the terms used herein are descriptive only and not limiting, and that various modifications may be made without altering the essence or scope of the invention.

Claims

[] What is being claimed is: [1] A charge-forming device for an internal combustion engine, comprising: a throttle body comprising a throttle bore with an inlet through which air flows into the throttle bore and an outlet from which a fuel-air mixture exits the throttle bore, wherein the throttle bore has a throat between the inlet and the outlet and the throat has a reduced flow area compared to the inlet and / or the outlet; a throttle valve having a valve head which is received in the throat of the throttle bore and is movable with respect to the throttle body between a first position and a second position, wherein the flow area between the valve head and the throttle body is larger when the valve head is in the second position compared to the first position. [2] The device according to claim 1, wherein the throttle bore has a converging section between the inlet and the throat and a diverging section between the throat and the outlet, and the flow area of ​​the converging section decreases in the direction from the inlet towards the throat and the flow area of ​​the diverging section increases in the direction from the throat towards the outlet. [3] The device according to claim 1, which furthermore has at least two fuel outlets which are open at one end towards the throat of the throttle bore and which are connected at the other end to a fuel supply through which fuel enters the throttle bore. [4] The device according to claim 3, wherein at least one fuel outlet is arranged between the throttle valve head and the outlet when the throttle valve is in the first position, and wherein at least one fuel outlet is arranged between the throttle valve head and the inlet when the throttle valve is in the first position. [5] The device according to claim 3, which further comprises a fuel chamber within the throttle body and in conjunction with the fuel outlets, as well as a vent passage formed in the throttle body and connected to the fuel chamber to provide an airflow into the fuel chamber. [6] The device according to claim 1, which further comprises an inlet fuel chamber in which a supply of liquid fuel is received and a fuel metering valve arranged in a fuel circuit between the inlet fuel chamber and the throttle bore, wherein the inlet fuel chamber has an outlet located directly above a region of the metering valve with respect to the direction of gravity. [7] The device according to claim 6, wherein the fuel metering valve is electrically actuated and a housing of the fuel metering valve is in direct heat transfer relationship with fuel from the inlet fuel chamber. [8] The device according to claim 6, wherein the fuel metering valve is supported by the throttle body or by a second body in which the inlet fuel chamber is defined. [9] The device according to claim 3, wherein the fuel outlets are formed in the throttle body. [10] The device according to claim 3, which further comprises a fuel metering valve with a housing connected to the throttle body, and wherein the fuel outlets are formed in the housing of the fuel metering valve. [11] The device according to claim 6, wherein the fuel metering valve comprises a solenoid having a wire coil around a coil body and an armature received in a passage in the coil body, and wherein the coil body has one or more gaps arranged and the area of ​​the surface defining the passage is reduced. [12] The device according to claim 3, which further comprises a fuel metering valve which is supported by the throttle body, and wherein the fuel supply is defined by a fuel chamber which is open to the outlets, and the fuel metering valve has an outlet which leads directly to the fuel chamber in order to supply fuel into the fuel chamber. [13] The device according to claim 12, wherein the fuel chamber is defined by a cavity in the throttle body and the fuel metering valve is partially received in the cavity and engages sealingly with the cavity. [14] The device according to claim 12, wherein the fuel chamber is defined in a housing which is connected to the throttle body, and the fuel metering valve is connected to the housing and engages with it in a sealing manner. [15] A fuel metering valve comprising: a coil former that defines a passage and has one or more gaps in the surface of the coil former that defines the passage; a coil of wire around the coil body; and an armature that is received within the passage in the coil body and is movable from a first position to a second position with respect to the coil body when current is supplied to the wire coil. [16] The valve according to claim 15, wherein the passage has an axis and the gaps are defined by several axially extending slots. [17] The valve according to claim 15, which further comprises a housing that covers the coil and has an inwardly extending end, wherein the coil body further comprises a fuel inlet, a fuel outlet and a valve seat between the fuel inlet and the fuel outlet, and wherein the inwardly extending end of the housing is open towards the fuel inlet, so that at least some fuel flowing through the fuel inlet engages with the inwardly extending end of the housing. [18] A charge-forming device for an internal combustion engine, comprising: a throttle body comprising a throttle bore with an inlet through which air flows into the throttle bore and an outlet from which a fuel-air mixture exits the throttle bore; a throttle valve having a valve head which is received within the throttle bore and is movable relative to the throttle body between a first position and a second position, wherein the flow area between the valve head and the throttle body is larger when the valve head is in the second position compared to the first position; an inlet fuel chamber into which a supply of liquid fuel is received; and a fuel metering valve arranged in a fuel circuit between the inlet fuel chamber and the throttle bore, wherein the inlet fuel chamber has an outlet located directly above a region of the metering valve with respect to the direction of gravity. [19] The device according to claim 18, which further comprises a fuel outlet which is open at one end towards the throat of the throttle bore and is connected at the other end to a fuel chamber which is provided between an outlet of the fuel metering valve and the fuel outlet, and wherein the fuel metering valve is supported by the throttle body. [20] The device according to claim 19, wherein the fuel chamber is defined by a cavity in the throttle body and the fuel metering valve is partially received in the cavity and engages sealingly with the cavity. [21] The device according to claim 19, wherein the fuel chamber is defined in a housing which is connected to the throttle body, and the fuel metering valve is connected to the housing and engages with it in a sealing manner.