The present disclosure relates to a fuel assembly for an internal combustion engine, and more particularly, to a pre-chamber fuel device of a fuel assembly.
An internal combustion engine may include at least one cylinder, a cylinder head coupled to the cylinder, at least one intake valve operably coupled to the cylinder head, and at least one exhaust valve operably coupled to the cylinder head. On engines with multiple intake and exhaust valves, the portion of the cylinder head between the exhaust valves, i.e., the exhaust bridge (“E-E bridge”), may be hotter than the portion of the cylinder head between the intake valves, i.e., the intake bridge (“I-I bridge”), and the portion of the cylinder head between one of the intake valves and one of the exhaust valves, i.e., the intake-exhaust bridge (“I-E bridge”), due to the elevated temperature of the exhaust gases exiting the cylinder.
Additionally, during combustion within the cylinder, the flame jets which initiate combustion also increase the temperature of the portions of the cylinder and cylinder head adjacent the jets. For example, any flame jets adjacent the E-E bridge of the cylinder head further increase the temperature thereof during combustion. As such, there is a need for orienting or directing flame jets away from the hottest portions of the cylinder and/or cylinder head to decrease the temperature thereof during operation of the engine.
In one embodiment, an engine comprises a cylinder having an internal combustion chamber and extending longitudinally, a cylinder head coupled to the cylinder, and a fuel-fed pre-chamber positioned within a portion of the cylinder head. The pre-chamber includes a pre-chamber volume and plurality of nozzle holes extending from the pre-chamber volume. The engine also comprises an ignition source positioned longitudinally above the pre-chamber volume and a locating member positioned on at least one of the pre-chamber and the cylinder head. The locating member is configured to position the pre-chamber in a predetermined orientation within the cylinder head.
In a further embodiment, an engine comprises a cylinder having a cylinder bore and extending along a longitudinal axis of the cylinder, a cylinder head coupled to the cylinder, and a fuel-fed pre-chamber positioned within a portion of the cylinder head. The pre-chamber includes a pre-chamber volume and plurality of nozzle holes extending from the pre-chamber volume. The plurality of nozzle holes have an asymmetrical configuration at a distal portion of the pre-chamber. The engine also comprises an ignition source positioned longitudinally above the pre-chamber volume.
In another embodiment, an engine comprises a cylinder extending along a longitudinal axis, a cylinder head coupled to the cylinder, and a pre-chamber positioned within a portion of the cylinder head. The pre-chamber includes a pre-chamber volume and plurality of nozzle holes extending from the pre-chamber volume. The engine also comprises at least one electronic fuel valve fluidly coupled to the pre-chamber volume.
In a further embodiment, a locating member is configured to maintain a longitudinal and rotational position of the pre-chamber. Additionally, the locating member may include a first locating member positioned on the pre-chamber and a second locating member positioned on the cylinder head.
In another embodiment, the first and second locating members are selected from the group consisting of a pin, a notch, a protrusion, a flat screw, a set screw, a tab, a recess, a shoulder, and a groove.
In a further embodiment, a plurality of nozzle holes are asymmetrically distributed about the pre-chamber. Additionally, the plurality of nozzle holes includes a first portion of nozzle holes positioned at a first portion of the pre-chamber and a second portion of nozzle holes positioned at a second portion of the pre-chamber, and the first portion of nozzle holes includes more nozzle holes than the second portion of nozzle holes.
In another embodiment, a plurality of nozzle holes includes a first portion of nozzle holes positioned at a first portion of the pre-chamber and a second portion of nozzle holes positioned at a second portion of the pre-chamber, and each nozzle hole of the first portion has a greater diameter than each of nozzle hole of the second portion.
In a further embodiment, a diameter of the at least one nozzle hole is 0.5-2.0% of a diameter of the cylinder bore.
In another embodiment, a circumferential separation between a first portion of the plurality of nozzle holes is greater than a circumferential separation between a second portion of the plurality of nozzle holes.
In a further embodiment, an angle relative to the longitudinal axis of the cylinder of at least one nozzle hole is greater than an angle relative to the longitudinal axis of the cylinder of a remainder of the nozzle holes.
In a further embodiment, a retaining clamp is configured to retain the pre-chamber within the cylinder head and positioned longitudinally above the pre-chamber volume.
In another embodiment, a fuel conduit fluidly is coupled to the at least one electronic fuel valve and the pre-chamber volume and having a length 1-5 times greater than an inner diameter of the fuel conduit. Additionally, the length of the fuel conduit may be 1-3 times greater than the inner diameter of the fuel conduit.
In a further embodiment, the ignition source is a spark plug retained within the pre-chamber.
In another embodiment, a plurality of nozzle holes are in an asymmetrical configuration at a distal portion of the pre-chamber.
The above mentioned and other features of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, where:
The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
Referring to
Engine 2 also includes an intake port 10 extending through a portion of cylinder head 6 and fluidly coupled to main combustion chamber 8, an exhaust port 12 extending through a portion of cylinder head 6 and fluidly coupled to main combustion chamber 8, at least one intake valve 14 operably coupled to cylinder head 6 and intake port 10, and at least one exhaust valve 16 operably coupled to cylinder head 6 and exhaust port 12.
Illustratively, as shown in
During operation of engine 2, the temperature of the exhaust gases exiting main combustion chamber 8 through exhaust port 12 may be elevated relative to the temperature of the intake air entering main combustion chamber 8 through intake port 10. As such, the temperature at E-E bridge 22 of cylinder head 6 may be greater than the temperature at I-I bridge 18 and/or I-E bridge 20, as disclosed further herein. Increased temperatures in portions of engine 2, such as at or adjacent E-E bridge 22, may undesirably increase the likelihood that knock will occur in cylinder 4. As disclosed further herein, certain aspects of engine 2 are configured to direct heat away from E-E bridge 22 to reduce the likelihood of knock.
Referring to
Referring still to
Fuel injector 28 may be electronically operated and includes an electronic fuel valve 38 at a distal end 40 thereof. Illustratively, fuel valve 38 may be an electronically-actuated poppet valve. As shown in
In one embodiment, fuel valve 38 may be electronically coupled to any electrical component(s) of engine 2 (e.g., an engine control unit) through a wired connection with wires 42 or through a wireless or other connection. In this way, fuel valve 38 may be electronically controlled to monitor and control the amount and timing of fuel distributed to main combustion chamber 8 through pre-chamber nozzle 33. Because fuel valve 38 may be electronically controlled, rather than mechanically controlled, the quantity and timing of the fuel distribution to main combustion chamber 8 may be more efficient and effective.
As shown in
Referring to
Alternatively, and as shown in
In an alternative embodiment shown in
By asymmetrically distributing nozzle openings 50 about pre-chamber nozzle 33 as disclosed in any of the embodiments herein, the flame jets formed in pre-chamber nozzle 33 during a fuel cycle may be directed into main combustion chamber 8 in a predetermined output path. For example, and disclosed further herein, the asymmetrical distribution of nozzle openings 50 may direct flame jets away from E-E bridge 22 or otherwise may direct the flame jets toward I-E bridge 20 or I-I bridge 18. More particularly, the flame jets may concentrate combustion and, therefore heat, in particular areas of main combustion chamber 8, thereby creating uneven heating and uneven combustion therein. However, by predetermining the direction and, therefore the concentration, of the flame jets within main combustion chamber 8, an increase in the uniformity of heating and/or combustion within main combustion chamber 8 may be achieved. In this way, the asymmetric distribution of nozzle openings 50 compensates for any asymmetry in heating and/or combustion within main combustion chamber 8 which decreases the likelihood that knock will occur. For example, larger concentrations of nozzle openings 50, nozzle openings 50 with larger diameters, and/or nozzle openings 50 with a decreased angle relative to longitudinal axis L of cylinder 4 may be oriented toward cooler portions of cylinder 4 and cylinder head 6 to increase combustion at these portions while small concentrations of nozzle openings 50, nozzle openings 50 with smaller diameters, and/or nozzle openings 50 with a greater angle relative to longitudinal axis L of cylinder 4 may be oriented toward hotter portions of cylinder 4 and cylinder head 6 to decrease the temperature and amount of combustion at these portions.
Referring to
By providing first and second locating members 44, 46, pre-chamber nozzle 33 is oriented according to the location(s) of locating members 44, 46 because first locating member 44 couples with or otherwise complements second locating member 46 to secure pre-chamber nozzle 33 to housing 32 and/or cylinder head 6. The predetermined orientation of pre-chamber nozzle 33 according to the positions of locating members 44, 46 fixes the rotational, longitudinal, and/or angular orientation of nozzle openings 50 of pre-chamber nozzle 33 to direct flame jets in a particular direction or toward a particular portion of main combustion chamber 8 during a fuel injection cycle. In this way, the flame jets from nozzle openings 50 are oriented for increased combustion due to increased turbulence within particular portions of main combustion chamber 8 and/or to direct the heat resulting from the flame jets and/or combustion away from other components of engine 2 which experience more heat, such as E-E bridge 22.
In one embodiment, pre-chamber nozzle 33 includes a plurality of first locating members 44 and/or cylinder head 6 or housing 32 also includes a plurality of locating members 46 such that pre-chamber nozzle 33 may be oriented in a plurality of predetermined configurations. As such, the orientation of pre-chamber nozzle 33 during installation of fuel assembly 24 with engine 2 may be based on specific applications of engine 2, such as the size or load of engine 2.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.