Fuel injector with variable hole size and spray angle nozzle and MHBIB

Abstract

Fuel injector (300) comprising: a nozzle body (302) having a proximal end (304) and a distal end (306); an upper row of nozzle holes (308), at least a plurality of which are evenly spaced around a first circumference of the nozzle body (302), the nozzle holes of the upper row having one or more diameters; and a lower row of nozzle holes (310) located between the distal end (306) and the upper row of nozzle holes (308), each of the nozzle holes (310) of the lower row having a diameter smaller than the one or more diameters of the nozzle holes (308) of the upper row; a nozzle hole at a center of the bottom of the nozzle body (302) and with a third diameter equal to the first diameter or the second diameter, wherein the upper row has a first number of holes that is greater than a second number of holes in the lower row; and where one of the first number of holes and the second number of holes is odd.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 058,958, filed October 2, 2014, entitled "VARIABLE HOLE SIZE NOZZLE AND SPRAY ANGLE FUEL INJECTOR AND MHBIB," the entire disclosure of which is expressly incorporated herein by reference. Technical area

[0002] The present disclosure generally relates to fuel injector and piston bowl shape configurations for use in a fuel injection system for an internal combustion engine. More specifically, the variable nozzle holes and piston bowl shape are configured, in combination or separately, to provide improved fuel dispersion in the combustion chamber to increase combustion efficiency and reduce emissions. background

[0003] Internal combustion engines produce air pollutants due to incomplete fuel combustion. Derivatives of incomplete combustion include carbon dioxide, water, and smoke, also known as particulate matter. These emissions are strictly regulated by the government. The emission of byproducts of the combustion process depends in part on the fuel-air mixture in the combustion chamber. One inefficient way currently known is to increase the emission of particulate matter by increasing the amount of air used during the combustion process. However, such an increase leads to increased production of nitrogen oxides (NOx), which is also strictly regulated. To reduce the production of NOx, a higher degree of exhaust gas recirculation (EGR) is used, but unfortunately, such use results in the generation of increased amounts of particulate matter.Other techniques, such as late injection timing and high injection pressure, can be used to reduce emissions of both NOx and particulate matter, but these have high initial costs.

[0004] The internal combustion engine can typically be divided into two engine operating modes: the low engine load mode and the high engine load mode. Controlling particulate matter emissions during low-load operation poses a significant challenge. However, it must still comply with strict government regulations. During low engine load operation, the air density in the combustion chambers is very low, offering little resistance to the spray penetration of fuel from the fuel injector. Therefore, it is difficult to comply with emissions regulations with current technology.

[0005] The nozzle of a direct-injection fuel injector may have multiple holes to disperse the amount of fuel into the combustion chamber. The diameter and spray angle of the nozzle holes also have a very strong effect on the combustion characteristics. Generally, all spray holes have the same diameter and angle. Therefore, such fuel injectors exhibit uniform spray penetration. Large-diameter nozzle holes can pose significant challenges in meeting emissions regulations under low engine load conditions. Due to uniform spray penetration, there is either an insufficient amount of energy in the fuel spray or insufficient air movement in the cylinder to properly mix the air and fuel as required for efficient combustion.These deficiencies often lead to incomplete combustion and consequently to the emission of higher amounts of particulate matter.

[0006] DE 10 2011 017 479 A1 discloses an internal combustion engine in which first injection ports and the second injection ports are arranged relative to one another such that, during an injection process, first injection jets from the first injection ports reach the piston essentially without contact with second injection jets from the second injection ports. Further combustion systems are known from DE 602 25 072 T2 and DE 100 32 336 A1.

[0007] There remains a need in the art for devices, processes and systems of different nozzle holes and piston bowl shapes that, when used together or separately, produce less particulate matter and allow the engine to meet emissions regulations without sacrificing the performance of aftertreatment systems and service life. Summary

[0008] In one embodiment, the present invention provides a fuel injector comprising: a nozzle body having a proximal end and a distal end, an upper row of nozzle holes evenly spaced around a first circumference of the nozzle body, and a lower row of nozzle holes located between the distal end and the upper row of nozzle holes, wherein the upper row has a first number of holes greater than a second number of holes in the lower row, and wherein one of the first number of holes and the second number of holes is odd. According to a second aspect of this embodiment, the nozzle holes of the upper row each have a first diameter and the nozzle holes of the lower row each have a second diameter, the first diameter having a ratio to the second diameter in the range of 3.2:1 to 1.5:1.In another aspect of this embodiment, the nozzle holes of the upper row each have a first angle relative to a horizontal axis of the nozzle body, and the nozzle holes of the lower row each have a second angle relative to the horizontal axis, the first angle having a ratio to the second angle in the range of 0.5:1 to 1.5:1. In yet another aspect of this embodiment, the nozzle holes of the upper row are configured to provide a fuel plume that conforms to a piston bowl shape. In this embodiment, the fuel injector further includes a nozzle hole at a center of the bottom of the nozzle body.In another aspect of this embodiment, each nozzle hole includes an inlet having an inlet diameter, an outlet having an outlet diameter, and a passage extending between the inlet and the outlet through the nozzle body, wherein the inlet diameter is different from the outlet diameter.

[0009] In a further, unclaimed embodiment of the present disclosure, a piston is provided comprising: a piston crown extending along a circumference of the piston and defining an uppermost surface of the piston, the piston crown defining a volume configured to receive fuel, a first piston bowl located radially inward of the piston crown, the first piston bowl having a bottom surface and a largest diameter at an interface between an outer annular wall of the first piston bowl and the uppermost surface of the piston, a second piston bowl located radially inward of the bottom surface of the first piston bowl and having an upper edge located below the uppermost surface of the piston, a third piston bowl located radially inward of the second piston bowl and having an upper edge,located below the uppermost surface of the piston, and a frusto-conical portion located radially inward from a bottom of the third piston bowl and having an upper surface located below the uppermost surface of the piston. Another aspect of this embodiment further includes a frusto-conical outer bottom portion connecting an inner wall of the second piston bowl and an outer wall of the third piston bowl, forming an inlet lip. In another aspect of this embodiment, the first, second, and third piston bowls each include annular concave portions. In yet another aspect, a fuel injector is configured to provide a fuel plume corresponding to a shape of the piston. According to yet another aspect of this embodiment, the piston crown has an inner lower surface,which coincides with a bottom surface of the piston crown.,

[0010] In a further unclaimed embodiment, a combustion system is provided comprising: a combustion chamber, a fuel injector disposed in flow communication with the combustion chamber, the fuel injector comprising: an upper row of nozzle holes, each having a first spray angle relative to a central axis of the fuel injector and a first diameter, and a lower row of nozzle holes, each having a second spray angle relative to the central axis of the fuel injector and a second diameter, and a piston disposed in the combustion chamber, the piston having a central axis coaxial with the central axis of the fuel injector, and a piston crown on a top surface of the piston, the piston crown defining a volume configured to receive fuel, the piston including a first piston bowl,located radially inward of the piston crown, the first piston bowl having: a bottom surface and a largest diameter at an interface between an outer annular wall of the first piston bowl and the top surface of the piston, a second piston bowl located radially inward of the bottom surface of the first piston bowl and having an upper edge located below the top surface of the piston, a third piston bowl located radially inward of the second piston bowl and having an upper edge located below the top surface of the piston, and a frustoconical portion located radially inward of a bottom of the third piston bowl and having an upper edge located below the top surface of the piston. According to one aspect of this embodiment, the fuel injector includes a fuel injector hole,which is centered on the central axis of the fuel injector at one end of the fuel injector. According to another aspect of this embodiment, the first diameter of the upper row of nozzle holes has a ratio to the second diameter of the lower row of nozzle holes in a range of 3.2:1 to 1.5:1. In another aspect of this embodiment, the first angle of the upper row of nozzle holes has a ratio to the second angle of the lower row of nozzle holes in a range of 0.5:1 to 1.5:1. In yet another aspect of this embodiment, the upper row of nozzle holes is positioned on the nozzle to inject fuel in a manner such that it impinges on an annular outer wall of the second piston bowl. In yet another aspect of this embodiment, the lower row of nozzle holes is positioned on the nozzle to inject fuel in a mannerso that it hits the third piston recess.

[0011] In yet another unclaimed embodiment of the present disclosure, a piston is provided comprising: a piston crown extending along a circumference of the piston and defining an uppermost surface of the piston, the piston crown defining a volume configured to receive fuel, a frusto-conical portion located at a center of the piston, the frusto-conical portion having an upper surface located below the uppermost surface of the piston, a first concave portion extending radially outward from the frusto-conical portion, the first concave portion having a first radius with a center located at a first distance from the uppermost surface of the piston, a frusto-conical outer bottom portion extending radially outward from the first concave portion, a second concave portion,extending radially outward from the frustoconical outer crown portion, the second concave portion having a second radius with a center located at a second distance from the top surface of the piston, the second radius of the second concave portion being greater than the first radius of the first concave portion, and the second distance being greater than the first distance, a first convex portion extending radially outward from the second concave portion, the first convex portion having a third radius with a center located at a third distance from the top surface of the piston, the third distance being less than the second distance, and a third concave portion extending radially outward from the first convex portion, the third concave portion having a fourth radius with a center,located at a fourth distance from the top surface of the piston, the fourth distance being less than the first distance. An aspect of this embodiment further includes a curved protrusion forming an inlet lip at an intersection of an outer surface of the first concave portion and the frustoconical outer crown portion.

[0012] In another unclaimed embodiment, a method is provided comprising injecting a fuel plume into a combustion chamber toward an outer bowl of a piston, and impinging the fuel plume upon an intake lip formed between the outer bowl and an inner bowl of the piston, wherein the intake lip redirects the fuel upon impingement to provide turbulence and additional fuel-air mixing in a central region of the piston. In another aspect of this embodiment, the outer piston bowl is configured to redirect injected fuel radially inward and upward toward a piston crown.

[0013] In yet another unclaimed embodiment of the present disclosure, a method is provided comprising: operating a fuel injector in response to a low engine load condition such that a first fuel injection event occurs in which fuel is injected into a combustion chamber from a nozzle of the injector having a plurality of holes arranged in a lower row and an upper row, the first fuel injection event injecting at least a portion of the fuel from the lower row, and operating the fuel injector in response to a high engine load condition such that a second fuel injection event occurs in which fuel is injected from the lower row and the upper row, the fuel injected in the first fuel injection eventmaintains a predetermined air-fuel ratio in a central region of a piston. In another aspect of this embodiment, wherein operating the fuel injector in response to a low engine load condition comprises directing fuel through the lower bank at a first angle relative to a plane including an uppermost surface of the piston, and operating the fuel injector in response to a high engine load condition comprises directing fuel through the upper bank at a second angle relative to the plane, the first angle being greater than the second angle. Short description of the drawings

[0014] The above-mentioned and other features of this disclosure and the manner in which they are obtained will become more apparent and the disclosure itself better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings in which: Fig. 1 is a side cross-sectional view showing a combustion system having a first piston embodiment according to the present disclosure; Fig. 2 an enlarged view of a nozzle hole of the fuel injection nozzle according to Fig. 1; Fig. 3 is a sectional side view showing a fuel injector; Fig. 3A is a sectional side view of an alternative embodiment of the fuel injector; Fig. 3B is a bottom view of the alternative embodiment fuel injector according to Fig. 3; Fig. 4A is a sectional bottom view of the fuel injector according to Fig. 3; and Fig. 4B is a sectional bottom view of the fuel injector of Fig. 3A and Fig. 3B.

[0015] Although the drawings illustrate embodiments of the various features and components according to the present disclosure, the drawings are not necessarily to scale, and certain features may be exaggerated to better illustrate and explain the present disclosure. The exemplary explanations presented herein illustrate embodiments of the disclosure, and such exemplary explanations are not to be construed as limiting the scope of the disclosure in any way. Detailed description of the embodiments

[0016] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, which are described below. It should be understood, however, that no limitation of the scope of the disclosure is intended thereby. The disclosure includes any changes and further modifications in the illustrated apparatus and the described method, and further applications of the principles of the disclosure that would normally occur to one skilled in the art to which the disclosure relates. Furthermore, the embodiments were chosen for description to enable one skilled in the art to practice the disclosure.

[0017] With reference now to Fig. 1 illustrates a combustion system 100 according to an embodiment of the present disclosure, including a fuel injector 102 (not fully shown), a cylinder 104, and a piston 106. The fuel injector 102 includes a nozzle body 108, a proximal end 110, and a distal end 112. In this embodiment, the fuel injector 102 includes a single row of holes 114 between the proximal end 110 and the distal end 112 of the nozzle body 108. The holes 114 are located on the nozzle body 108. The holes 114 may have different diameters or the same diameter. Each hole 114 has a spray angle relative to a plane perpendicular to a central axis 116 of the nozzle body 108. The holes 114 may have different spray angles or the same spray angle. The holes 114 are arranged at a regular interval around a circumference of the nozzle body 108.

[0018] The cylinder 104 generally includes a cylinder cavity 122 and a piston 106. The cylinder 104 is generally formed within an engine block (not shown). A cylinder head (not shown) is positioned on a top surface 126 of the cylinder 104. The bottom surface of the cylinder head is attached to the engine block, which closes the cylinder 104 from its top surface 126 and forms a combustion chamber 136. The piston 106 is slidably disposed within the cylinder 104. The cylinder head includes an exhaust passage (not shown), an intake passage (not shown), and an injector bore (not shown). The fuel injector 102 is securely mounted within the injector bore formed within the cylinder head for injecting fuel into the combustion chamber 136.The exhaust passage formed in the cylinder head directs exhaust gases to the combustion chamber 136 and an intake passage directs intake air into the combustion chamber 136.

[0019] The piston 106 generally includes a depending cylindrical wall 128, an uppermost surface 134, a piston crown 130, and a lower surface 132. The central axis 116 of the fuel injector 102 is also a central axis of the piston 106. The uppermost surface 134 of the piston 106 cooperates with the cylinder head and a portion of the cylinder 104 extending between the cylinder head and the piston 106 to define the combustion chamber 136. The cylindrical wall 128 includes a plurality of annular grooves 118 for receiving corresponding piston rings 120 configured to form a relatively light combustion gas seal between the piston 106 and the cylinder 104. Although in Fig. 1, the piston 106 is connected to a crankshaft by means of a connecting rod which causes the piston 106 to reciprocate along a rectilinear path within the cylinder 106 while the crankshaft rotates in a manner known in the art.

[0020] Furthermore, with reference to Fig. 1, an upper portion of the piston 106 is referred to as the piston crown 130. The piston crown 130 is configured to receive fuel from the fuel injector 102. The piston crown 130 further includes an uppermost surface partially defining the combustion chamber 136 and an outer bowl or first piston bowl 138 formed by an outwardly opening cavity. The first piston bowl 138 has a bottom surface 140 and a largest diameter at an interface between the uppermost surface 134 of the piston 106 and an annular inner wall of the first piston bowl 138. A main or second piston bowl 142 is centrally located within the first piston bowl 138 such that an upper edge 170 of the second piston bowl 142 is lower than the uppermost surface 134 of the piston 106. A third piston bowl 146 is located radially inside the second piston bowl 142.Similarly to the second piston bowl 142, an upper edge 172 of the third piston bowl 146 is lower than the uppermost surface 134 of the piston 106. A frustoconical portion 152 is located within the third piston bowl 146. A frustoconical outer crown portion 149 connects an outer wall of the third piston bowl 146 and an inner wall of the second piston bowl 142 to form an annular spray targeting lip or inlet lip 150.

[0021] The first piston bowl 138 forms a concave portion having a radius R4. The radius R4 has a center 164 located at a distance D4 from a plane 124 that includes the top surface 134 of the piston 106. Similarly, the second piston bowl 142 forms an annular concave portion having a radius R2. The radius R2 has a center 156 located at a distance D2 from the plane 124. A convex portion 158 is formed between the first piston bowl 138 and the second piston bowl 142 and has a radius R3. The radius R3 has a center 160 located at a distance D3 from the plane 124. The third piston bowl 146 forms an annular concave portion having a radius R1 with a center 162 located at a distance D1 from the plane 124.

[0022] Various features described hereinabove are positioned in a specific relationship to one another, as described below. A bottom surface 144 of the second piston bowl 142 is lower (relative to plane 124) than the bottom surface 140 of the first piston bowl 138. Furthermore, a bottom surface 148 of the third piston bowl 146 is higher than the bottom surface 144 of the second piston bowl 142. Furthermore, the largest diameter of the second piston bowl 142 is smaller than the largest diameter of the first piston bowl 138, and the largest diameter of the third piston bowl 146 is smaller than the largest diameter of the second piston bowl 142. Finally, the top surface 154 of the frustoconical portion 152 is lower than the top surface 134 of the piston 106.

[0023] At a radial distance from the central axis 116 of the piston 106, the center 156 of the radius R2 is positioned between the central axis 116 of the piston 106 and the center 160 of the radius R3. The center 162 of the radius R1 is positioned between the central axis 116 of the piston 106 and the center 156 of the radius R2. The center 164 of the radius R4 is positioned between the center 156 of the radius R2 and the center 160 of the radius R3. With respect to axial distances, the distance D2 is greater than D1, which in turn is greater than D4 (D2>D1>D4). The distance D2 is also greater than D3. Furthermore, with respect to various radii of concave and convex portions described above, the radius R1 is smaller than the radius R2 (R1 <R2).

[0024] Continuing with Fig. 1, fuel injected from holes 114 enters the combustion chamber 136 at different angles or the same angle, forming a nominal cone along the fuel spray visibility area. As the fuel exits the holes 114, it fragments after reaching a critical fluid length depending on flow conditions and ambient conditions, such as fuel viscosity. Upon fragmentation, the sprayed fuel assumes a nominally conical shape (as in Fig. 1) with a specific cone angle. A volume portion of sprayed fuel hits the second piston bowl 142, but a small portion of the inlet lip 150 is sheared off and redirected toward the third piston bowl 146, creating a flow motion as shown in Fig. 1. This redirected fuel mixes with unused air at the center of the combustion chamber 136, thereby adding turbulence for improved combustion.

[0025] With reference now to Fig. 2, an enlarged view of one of the holes 114 is illustrated. The holes 114 or bores include an inlet 202, an outlet 204, and a passage 210. The passage 210 extends between the inlet 202 and the outlet 204 through the nozzle body 108. Highly pressurized fuel flows from the inlet 202 to the outlet 204 via the passage 201. The inlet 202 has a diameter that is different than a diameter of the outlet 204. In this example, the inlet diameter is larger than the outlet diameter. Furthermore, the inlet 202 has curved edges configured to reduce turbulence that can cause cavitation. It should be understood from the above description that any combination of the diameter of the inlet 202 and the diameter of the outlet 204 may be included in an embodiment of the present disclosure.

[0026] With reference now to Fig. 3, a fuel injector 300 (not fully shown) is illustrated having a plurality of rows of nozzle holes. The fuel injector 300 includes a nozzle body 302, a proximal end 304, a distal end 306, an upper row of nozzle holes 308, a lower row of nozzle holes 310, and a central axis 312. The upper row of nozzle holes 308 is positioned between the proximal end 304 and the distal end 306 of the nozzle body 302 to allow a spray plume emanating from the upper row of nozzle holes 308 to form a generally conical shape and mix with high temperature air in a main piston bowl in a combustion chamber (such as the second piston bowl 142 of Fig. 1). The lower row of nozzle holes 310 is positioned between the upper row of nozzle holes 308 and the distal end 306 of the nozzle body 302 to allow high-pressure fuel to flow into a high-pressure combustion chamber to initiate thorough mixing of high-temperature fuel and compressed air in a central region of the combustion chamber.

[0027] Each hole of the upper row 308 includes a first diameter and a first spray angle, or main fuel spray angle, relative to a plane horizontal to the central axis 312. Similarly, each hole of the lower row 310 includes a second diameter and a second spray angle relative to a plane horizontal to the central axis 312. Each hole of the upper row 308 is placed equidistant from another around a circumference of the upper row. Furthermore, the total number of holes in each of the upper row 308 and the lower row 310 is always different, so that if the total number of holes in the upper row of nozzle holes 308 is an even number, then the total number of holes in the lower row of nozzle holes 310 is an odd number.In addition, if the total number of holes in the upper row of nozzle holes 308 is an odd number, the total number of holes in the lower row of nozzle holes 310 may be an even number or an odd number.

[0028] In one embodiment of the present disclosure, a ratio between the first diameter of the upper row of holes 308 and the second diameter of the lower row of holes 310 is within a range of 3.2:1 to 1.5:1. Furthermore, a ratio between the first spray angle of the upper row of holes 308 and the second spray angle of the lower row of holes 310 is within a range of 0.5:1 to 1.5:1. Depending on the implementation of the present disclosure, the ratio between the first diameter of the upper row of holes 308 and the second diameter of the lower row of holes 310 may be higher or lower. Similarly, the ratio between the first spray angle of the upper row of holes 308 and the second spray angle of the lower row of holes 310 may be higher or lower based on the implementation of the present disclosure.

[0029] Another embodiment of the present disclosure includes a hole 316 at a bottom center of the distal end 306 of the nozzle body 302. The diameter and spray angle of the bottom center hole 316 is the same as or different from the first diameter and first spray angle of the upper row 308 and the second diameter and second spray angle of the lower row 310. As explained above, the total number of holes in each of the upper row 308 and the lower row 310 is always different, so that at least a total number of holes in the upper row 308 or the lower row 310 is always odd. Furthermore, it should be understood from the above description that Fig. 2 is intended to illustrate a hole from any of the upper row of holes 308, lower row of holes 310 and the hole 316 of the bottom center of the nozzle body 302.

[0030] As in Fig. 3A, Fig. 3B and Fig. 4B, an alternative embodiment of the fuel injector 300' includes a nozzle body 302' with at least one hole 320 defining a lower "row" and an upper row 322 of nozzle holes 324 positioned longitudinally above the hole 320. The diameter and spray angle of the hole(s) 320 is the same as or different from the diameter and spray angle of the holes 322. The total number of nozzle holes of the fuel injector 300' is determined by the sum of the number of nozzle holes 324 in the upper row 322 plus the hole(s) 320. For example, the upper row 322 includes one fewer nozzle hole than the total number of nozzle holes of the fuel injector 300', with the final one nozzle hole being defined by the hole 320.In one embodiment, the total number of nozzle holes of the fuel injector 300' may be 5 to 12 nozzle holes. For example, if the fuel injector 300' includes a total of seven nozzle holes, then the upper row 322 includes six nozzle holes 324 and the lower "row" includes hole 320 for a total of seven nozzle holes. Similarly, if the fuel injector 300' includes a total of 10 nozzle holes, the upper row 322 includes nine nozzle holes 324 and the lower "row" includes hole 320 for a total of 10 nozzle holes.

[0031] The hole(s) 320 may be radially and / or axially offset from the bottom center of the distal end 306 of the nozzle body 302' and any holes 322. As shown in Fig. 3B and Fig. 4B, the hole(s) 320 and the holes 324 together are evenly distributed around the circumference of the nozzle body 302', however, the hole(s) 320 is (are) longitudinally below the holes 324. The holes 324 are evenly distributed around the circumference of the nozzle body 302 at the longitudinal position of the upper row 322 when the upper row 322 includes the total number of nozzle holes of the fuel injector 300'. However, because the upper row 322 includes, for example, one hole less than the total number of nozzle holes, there is at least one gap 326 in the nozzle body 302'. The gap(s) 326 correspond(s) to the position of the final nozzle hole(s) of the fuel injector 300', i.e., the hole(s) 320 positioned longitudinally below the gap(s) 326. In this way, the hole(s) 320 are longitudinally offset from the bottom center of the distal end 306 of the fuel injector 300' and positioned longitudinally below the gap 326 and not below any of the holes 322.

[0032] By defining the hole(s) 320 as the only nozzle hole at the distal end 306 of the nozzle body 302', fuel flowing along a needle (not shown) from the nozzle body 302' first flows into the hole(s) 320 before flowing through the holes 322. In this way, fuel initially flows from the hole 320, which initiates combustion by forcing a small amount of fuel into the cylinder 104 ( Fig. 1). The fuel flowing through holes 324 then flows into cylinder 104 to enhance combustion therein. As such, the fuel initially flowing through hole(s) 320 provides a pre-combustion amount of fuel to cylinder 104 to initiate combustion therein, resulting in more complete combustion when the fuel flowing through nozzles 324 from upper bank 322 flows into cylinder 104.

[0033] With reference now to Fig. 4A, an exemplary embodiment of the fuel injector 300 of the present disclosure is shown. The fuel injector 300 includes seven holes in the upper row 308 and two holes in the lower row 310. As shown, the diameter of the inlet 402 of each hole of the upper row 308 and the lower row 310 is larger than the diameter of the outlet 404. It should be understood from the present disclosure that in some embodiments, the upper row of holes 308 may have an inlet 402 diameter that is larger than the outlet 404 diameter, and in the same embodiment, the lower row of holes 310 may have an inlet 402 diameter that is smaller than the outlet 404 diameter, and vice versa.

[0034] The fuel injector 300 operates as in Fig. 4A illustrates two events, namely: a first fuel injection event and a second fuel injection event. In both events, the fuel injector 300 injects a plume of fuel into a combustion chamber (such as the chamber 136 of Fig. 1); however, the fuel is injected from either the lower row of holes 308 or the upper row of holes 310, or in some cases, both. The upper row of holes 308 is configured so that most of the fuel is directed toward a main piston bowl (such as the second piston bowl 142 of Fig. 1). It It should be understood from the present disclosure that various types of piston bowl shapes can be used in combination with the fuel injector 300. The lower row of nozzle holes 310 is configured so that fuel injected therefrom reaches a central region of the piston 106. As illustrated above, an upper row of holes 308 sprays fuel at a different angle than the lower row of holes 310. As the piston 106 moves toward the top dead center position during a compression stroke, fuel is injected into the combustion chamber 136 from the fuel injector 300. Under low engine load conditions, a majority of the fuel is injected from the lower row of holes 310 and mixes with unburned air in a central region of the piston. 106. Under high engine load conditions, fuel is injected through the lower row of holes 310 as well as the upper row of holes 308.

[0035] While the embodiments have been described with exemplary configurations, the present disclosure 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 disclosure using its general principles. This application is further intended to cover such departures from the present disclosure as are within known or customary practice in the art. to which this invention is directed.

Claims

[1] Fuel injector (300) comprising: a nozzle body (302) having a proximal end (304) and a distal end (306); an upper row of nozzle holes (308), at least a plurality of which are evenly spaced around a first circumference of the nozzle body (302), the nozzle holes of the upper row having one or more diameters; and a lower row of nozzle holes (310) located between the distal end (306) and the upper row of nozzle holes (308), each of the nozzle holes (310) of the lower row having a diameter smaller than the one or more diameters of the nozzle holes (308) of the upper row; a nozzle hole at a center of the bottom of the nozzle body (302) and with a third diameter equal to the first diameter or the second diameter, wherein the upper row has a first number of holes that is greater than a second number of holes in the lower row; and where one of the first number of holes and the second number of holes is odd. [2] The fuel injector (300) of claim 1, wherein the nozzle holes (308) of the upper row each have a first diameter and the nozzle holes (310) of the lower row each have a second diameter, the first diameter having a ratio to the second diameter in the range of 3.2:1 to 1.5:

1. [3] The fuel injector (300) of claim 1, wherein the nozzle holes (308) of the upper row each have a first angle relative to a horizontal axis of the nozzle body (302) and the nozzle holes (310) of the lower row each have a second angle relative to the horizontal axis, the first angle having a ratio to the second angle in the range of 0.5:1 to 1.5:

1. [4] The fuel injector (300) of claim 1, wherein the nozzle holes (308) of the upper row are configured to provide a fuel plume corresponding to a shape of a piston bowl (138, 142, 146). [5] The fuel injector (300) of claim 1, wherein each nozzle hole comprises an inlet (202, 402) having an inlet diameter, an outlet (204, 404) having an outlet diameter, and a passage (210) extending through the nozzle body (302) between the inlet (202, 402) and the outlet (204, 404), the inlet diameter being different from the outlet diameter.

Images