Fuel injector

Abstract

A fuel injector for an internal combustion engine is provided. The fuel injector includes a first needle arranged to control injection of a first fuel and extending along an injector longitudinal axis. The fuel injector also includes a first control chamber associated with the first valve needle. The fuel injector also includes an actuator assembly extending axially along an actuator longitudinal axis from an upper surface to an opposing lower surface. The actuator assembly includes a first control valve arranged to vary a pressure of the control fluid in the first control chamber to cause opening and closing movement of the first valve needle along the injector longitudinal axis.

Description

Technical Field

[0001] This application relates to a fuel injector and an internal combustion engine including the fuel injector. Background Technology

[0002] The following discussion of the background of the invention is intended only to aid in understanding the invention. It should be understood that this discussion is not an admission or endorsement that any material mentioned is publicly available, known, or part of common general knowledge to those skilled in the art within any jurisdiction at the priority date of this invention.

[0003] Internal combustion engines used in heavy industrial applications typically use diesel fuel. However, there is growing interest in using alternative, cleaner combustion fuels—including gaseous fuels. However, because many alternative fuels, such as methanol, ammonia, natural gas, and hydrogen, have high autoignition temperatures, ignition assistance is often required. In some engine systems, including diesel cycle engine systems, ignition injection is used to ignite fuels with lower autoignition temperatures—such as diesel fuel—that do not reliably ignite in the combustion chamber of an internal combustion engine due to the heat of compression. As used herein, autoignition temperature is the lowest temperature at which a substance will spontaneously ignite without an external ignition source—such as a flame or spark. For example, the autoignition temperature of normal diesel fuel in normal atmospheric conditions is approximately 210°C, and for natural gas, depending on fuel quality, it is approximately 540°C. In one type of internal combustion engine, both the alternative main fuel and the ignition fuel are injected directly into the combustion chamber. Due to space constraints in the engine cylinder head, it is desirable to use a dual-fuel injector per cylinder to inject both fuels. Dual-fuel injectors are adapted to maintain two fuels separate within the injector and deliver the respective fuels independently at appropriate times. Exemplary fuel injectors and methods operating in internal combustion engine systems have been described in the applicant’s prior patents, including US7373931, US8095294, US10167786, US11053866, and the commonly owned US10294908, all of which are incorporated herein by reference.

[0004] Typically, dual-fuel injectors are equipped with a dual-nozzle arrangement with an inner valve needle and an outer valve needle. The inner and outer valve needles engage with corresponding valve seats at their lower ends to control fuel flow through corresponding inner and outer discharge orifice groups. The outer valve needle controls the injection of gaseous fuel through the outer discharge orifice group, while the inner valve needle controls the injection of diesel fuel through the inner discharge orifice group. The inner and outer valve needles are independently controlled by two solenoid valves configured to control the pressure of the control fluid (such as diesel fuel) in the corresponding control chambers of the inner and outer valve needles. Each control chamber receives the upper end of its corresponding needle, such that changing the pressure of the control fluid in each control chamber alters the downward (closing) force acting on the corresponding needle. The control chamber receiving the upper end of the outer valve needle is associated with a "master needle control valve." The control chamber receiving the upper end of the inner valve needle is associated with an "ignition needle control valve."

[0005] When the pressure of the control fluid in the control chamber is relatively high, the downward force of the fuel (gas or diesel) is greater than the upward force, and the corresponding needle remains seated. When the pressure of the control fluid is relatively low, the upward force overcomes the downward force, and the corresponding needle opens to allow fuel injection through the corresponding discharge orifice group. Each control chamber is connected to the control fluid source at a relatively high pressure. Each control valve is operable to connect the corresponding control chamber to a low-pressure discharge channel for the control fluid. In this way, opening each control valve causes a decrease in the pressure of the control fluid in the corresponding control chamber, thereby opening the corresponding valve needle.

[0006] In some dual-fuel injectors, high pressure in the control fluid in the exhaust passage can interfere with the timing and opening / closing rate of the master needle control valve. Furthermore, pressure imbalances in the exhaust passage can cause the master needle control valve to reopen at inappropriate times. For example, when a large mass flow of control fluid passes through the master needle control valve for discharge, the individual fluid passages in a dual injector may experience pressure reflections at the points where injector components intersect. The presence of pressure reflections and pressure fluctuations in the exhaust passage can lead to inappropriate fuel mixing, inappropriate timing of fuel injection, and inappropriate timing of other injection event control. Because the amount of fuel delivered to the combustion chamber affects engine torque output, pressure fluctuations in the exhaust passage of a dual-fuel injector can provide undesirable torque output to the engine. Furthermore, inappropriate fuel mixing caused by pressure fluctuations in the exhaust passage of a dual-fuel injector can also lead to undesirable exhaust emissions from the engine. Such pressure reflection and pressure fluctuation problems in the exhaust passage may also be observed in conventional fuel injectors with one or more control valves, where the fluid returning to the exhaust passage can generate undesirable back pressure and / or generate uneven fluid forces acting on the surfaces of the control valves. The term “and / or” as used herein means “one or the other or both”.

[0007] Therefore, existing technologies lack techniques for reducing pressure fluctuations and pressure reflections in the exhaust passage / exhaust circuit of a fuel injector. This disclosure provides a technique for preventing pressure imbalances / fluctuations and pressure reflections in the exhaust passage of a fuel injector, thereby improving the overall performance of the fuel injector and the internal combustion engine including the fuel injector. Summary of the Invention

[0008] An improved fuel injector for an internal combustion engine includes a first valve needle arranged to control the injection of a first fuel. The first valve needle extends along a longitudinal axis of the injector. The fuel injector also includes a first control chamber associated with the first valve needle. The fuel injector further includes an actuator assembly extending axially along an actuator longitudinal axis from an upper surface to an opposing lower surface. The actuator assembly includes a first control valve arranged to change the pressure of a control fluid in the first control chamber to cause opening and closing movement of the first valve needle along the longitudinal axis of the injector. The fuel injector also includes a manifold disposed on the actuator assembly. The manifold includes a bottom surface that at least partially contacts the upper surface of the actuator assembly at a manifold-actuator interface. The manifold also includes a return inlet extending through the manifold from the manifold-actuator interface. The return inlet is configured to selectively fluidly communicate with the first control chamber such that the return inlet selectively receives control fluid from the first control chamber. The fuel injector also includes a body configured to be adjacent to an actuator assembly opposite to a manifold, and the body extending axially from an upper body surface to an opposite lower body surface. The body at least partially houses the actuator assembly. The fuel injector also includes a cylinder extending axially from an upper cylinder surface to an opposite lower cylinder surface. The cylinder includes an annular outer surface extending between the upper and lower cylinder surfaces. The upper cylinder surface of the cylinder at least partially contacts the lower body surface of the body at the body-cylinder interface. The fuel injector also includes a nozzle configured to be adjacent to the cylinder opposite to the body and at least partially contact the lower cylinder surface of the cylinder. The fuel injector also includes a first discharge passage configured to be in fluid communication with a return inlet of the manifold. The first discharge passage includes a first discharge inlet arranged to receive control fluid and a first discharge outlet arranged to discharge control fluid. The first discharge passage extends through the body, across the body-cylinder interface, and along the annular outer surface of the cylinder, such that the first discharge outlet of the first discharge passage is located below the upper cylinder surface and on the annular outer surface of the cylinder.

[0009] An improved fuel injector for an internal combustion engine includes a first valve needle arranged to control the injection of a first fuel. The first valve needle extends along a longitudinal axis of the injector. The fuel injector also includes a first control chamber associated with the first valve needle. The fuel injector further includes an actuator assembly extending axially along an actuator longitudinal axis from an upper surface to an opposing lower surface. The actuator assembly includes a first control valve arranged to change the pressure of a control fluid in the first control chamber to cause opening and closing movement of the first valve needle along the longitudinal axis of the injector. The fuel injector also includes a manifold disposed on the actuator assembly. The manifold includes a bottom surface that at least partially contacts the upper surface of the actuator assembly at a manifold-actuator interface. The manifold also includes a return inlet extending through the manifold from the manifold-actuator interface. The return inlet is configured to selectively fluidly communicate with the first control chamber such that the return inlet selectively receives control fluid from the first control chamber. The manifold also includes multiple return channels spaced at an angle around the longitudinal axis of the actuator and in fluid communication with the return inlet above the bottom surface of the manifold. Each of the multiple return channels is inclined relative to the longitudinal axis of the actuator and extends downward from the return inlet through the manifold to the bottom surface. Each return channel is arranged to receive control fluid from the return inlet.

[0010] An improved fuel injector for an internal combustion engine includes a first valve needle arranged to control the injection of a first fuel. The first valve needle extends along a longitudinal axis of the injector. The fuel injector also includes a first control chamber associated with the first valve needle. The fuel injector further includes an actuator assembly extending axially along an actuator longitudinal axis from an upper surface to an opposing lower surface. The actuator assembly includes a first control valve arranged to change the pressure of a control fluid in the first control chamber to cause opening and closing movement of the first valve needle along the longitudinal axis of the injector. The fuel injector also includes a body disposed adjacent to the actuator assembly and extending axially from an upper body surface to an opposing lower body surface. The body at least partially houses the actuator assembly. The body includes a first inlet arranged to receive the first fuel within the fuel injector. The fuel injector also includes a cylinder extending axially from an upper cylinder surface to an opposing lower cylinder surface. The cylinder includes an annular outer surface extending between the upper and lower cylinder surfaces. The upper cylinder surface of the cylinder at least partially contacts the lower body surface of the body at the body-cylinder interface. The fuel injector also includes a nozzle configured to be adjacent to and at least partially in contact with the lower surface of the cylinder, opposite to the body. The nozzle includes a chamber junction and a set of first discharge orifices. The chamber junction is arranged to selectively receive first fuel from a first inlet, and the set of first discharge orifices is configured to be in fluid communication with the chamber junction. The fuel injector also includes a plurality of high-pressure channels extending from the first inlet to the chamber junction. As fluid flows toward the chamber junction, the cross-sectional flow area of ​​each of the plurality of high-pressure channels decreases or remains substantially the same along the length of the high-pressure channel downstream of the first inlet. Attached Figure Description

[0011] The accompanying drawings, which are incorporated in and form part of this specification, illustrate specific embodiments of the apparatus, system, and method, and together with the foregoing general description and detailed description of specific embodiments, serve to explain the principles of the apparatus, system, and method.

[0012] Figure 1 This is a schematic diagram of an internal combustion engine according to an embodiment of the present disclosure; Figure 2 According to an embodiment of the present disclosure Figure 1 A side view of the fuel injector of an internal combustion engine; Figure 3 According to an embodiment of the present disclosure Figure 2 A side sectional view of the fuel injector; Figure 4 According to an embodiment of the present disclosure Figure 2 A partial sectional view of the fuel injector from the front; Figure 5 According to an embodiment of the present disclosure Figure 2 A perspective view of the actuator assembly of the fuel injector; Figure 6A According to an embodiment of the present disclosure Figure 2 A side view of the fuel injector manifold, with some internal components shown in dashed lines; Figure 6B According to an embodiment of the present disclosure Figure 6A A front view of the manifold, with some internal components shown in dashed lines; Figure 7A According to an embodiment of the present disclosure Figure 2 A partial front view of the fuel injector manifold and actuator assembly; Figure 7B According to an embodiment of the present disclosure Figure 7A A top view of the manifold and actuator assembly; Figure 8 This is a top view of a portion of the manifold and actuator assembly of a fuel injector according to another embodiment of the present disclosure; Figure 9 According to an embodiment of the present disclosure Figure 2 A partial sectional side view of the fuel injector barrel and body; Figure 10A According to an embodiment of the present disclosure Figure 9 Side perspective view of the cylinder; Figure 10B According to an embodiment of the present disclosure Figure 9 The front view of the cylinder; Figure 10C According to an embodiment of the present disclosure Figure 9 Top view of the cylinder; Figure 11A This is a side perspective view of the lower cover nut according to an embodiment of the present disclosure; Figure 11B According to an embodiment of the present disclosure Figure 11A Side sectional view of the lower cover nut; Figure 12A According to an embodiment of the present disclosure Figure 2 A side perspective view of the first line in the fuel injector; Figure 12B According to an embodiment of the present disclosure Figure 12A Rear view of the first conduit; and Figure 13 This illustrates an embodiment according to the present disclosure. Figure 12A The total cross-sectional flow area of ​​the first pipeline and based on Figure 2 A graph showing the relationship between the length of the first fuel inlet of the fuel injector and the length of the first pipeline. Detailed Implementation

[0013] Throughout this specification and claims, the following terms take their explicitly associated meanings unless the context clearly indicates otherwise. The phrases “in some embodiments,” “in exemplary embodiments,” “in multiple exemplary embodiments,” and “in some exemplary embodiments” as used herein do not necessarily refer to the same embodiment, although they may refer to the same embodiment. Furthermore, the phrases “in other embodiments,” “another embodiment,” and “in some other embodiments” as used herein do not necessarily refer to different embodiments, although they may refer to different embodiments. Therefore, as described below, various embodiments of the invention can be readily combined without departing from the scope of the invention.

[0014] Unless otherwise specifically stated or understood in the context in which they are used, conditional language such as “may,” “can,” or “may” is generally intended to convey that some embodiments include (while others do not) certain features, elements, and / or steps.

[0015] refer to Figure 1 The diagram illustrates an internal combustion engine 50 according to an embodiment of the present disclosure. The internal combustion engine 50 can be used in vehicles, and can also be used in ships, locomotives, mining transportation, power generation, or static applications. In other words, the internal combustion engine 50 can be a light-duty engine, a medium-duty engine, a heavy-duty engine, or a high-horsepower (HHP) engine.

[0016] The internal combustion engine 50 is capable of using liquid and / or gaseous fuels. In some embodiments, gaseous fuel may be used as the primary fuel of the internal combustion engine 50, and liquid fuel may be used as the ignition fuel of the internal combustion engine 50. As used herein, gaseous fuel is any fuel that is in a gaseous / gas phase at standard temperature and pressure, which, in the context of this application, is defined as a temperature of zero (0) degrees Celsius (°C) and an absolute pressure of one hundred (100) kilopascals (kPa).

[0017] The internal combustion engine 50 includes a cylinder 52. The cylinder 52 defines a cylinder axis CA along its length. The internal combustion engine 50 also includes a cylinder head 54 disposed on the cylinder 52. The cylinder head 54 covers the top of the cylinder 52. The internal combustion engine 50 also includes a piston 56 movable within the cylinder 52. Specifically, the piston 56 is reciprocating within the cylinder 52. The internal combustion engine 50 also includes a combustion chamber 58 defined by the cylinder 52, the cylinder head 54, and the piston 56.

[0018] The internal combustion engine 50 also includes a hydraulically actuated fuel injector 100, which can be mounted in the cylinder head 54 for directly introducing fuel into the combustion chamber 58. The fuel injector 100 extends at least partially through the cylinder head 54 into the combustion chamber 58. The fuel injector 100 is adapted to independently deliver the pilot fuel and the main fuel at their respective appropriate timings. Figure 1 In the illustrated embodiment, the internal combustion engine 50 can operate with two fuels (e.g., a liquid ignition fuel and a main fuel having a higher autoignition temperature than the ignition fuel). In other embodiments, the internal combustion engine 50 can employ a hydraulically actuated fuel injector with only a single needle, which does not include an orifice for the ignition needle, and the fuel injector does not require an ignition actuation mechanism. Hydraulic fluid can be used as the ignition fuel, and the hydraulic fluid inlet can also be used as the ignition fuel inlet, thereby allowing a match-fit or other channel to operate to allow ignition fuel with a desired flow rate into the main fuel chamber (plenum). In some embodiments, the ignition fuel can be injected from a separate ignition injector (not shown), or other well-known ignition aids, such as hot surfaces (e.g., glow plugs), spark plugs, and catalytic elements, can be used instead of or in combination with the ignition fuel.

[0019] It should be understood that, for the purposes of simplification and clarity, some conventional components of the internal combustion engine 50 are not shown. Furthermore, only a cross-section of the internal combustion engine 50 showing the combustion chamber 58 of one cylinder (i.e., cylinder 52) is shown; however, those skilled in the art will understand that the internal combustion engine 50 may include other components and multiple cylinders.

[0020] Figure 2 According to an embodiment of the present disclosure, it is used for Figure 1 Side view of the fuel injector 100 of the internal combustion engine 50. Figure 3 This is a side sectional view of the fuel injector 100. Figure 4 This is a partial sectional view of the fuel injector 100 from the front. (Reference) Figures 2 to 4 The fuel injector 100 is adapted to inject a primary first fuel F1 and a second fuel F2 as an ignition fuel. The first fuel F1 may be the same fuel as the second fuel or a different fuel; and in an exemplary embodiment, the first fuel F1 is a gaseous fuel and the second fuel F2 is a liquid fuel. In some embodiments, the liquid fuel is diesel fuel. In some embodiments, the gaseous fuel is hydrogen. In some embodiments, the gaseous fuel is selected from the group consisting of natural gas, hydrogen, propane, ethane, butane, methane, ammonia, and mixtures thereof. In some other embodiments, the first fuel F1 may be a liquid fuel such as ethanol or methanol.

[0021] Fuel injector 100 comprises multiple components stacked on top of each other and securely held together by two or more cap nuts. Fuel injector 100 extends along the injector longitudinal axis LA1 from a top head 102 to a nozzle tip 104. The injector longitudinal axis LA1 is commensurate with the cylinder axis CA (in... Figure 1 (As shown in the image) overlaps, but this is not necessary. According to... Figure 3 In any orientation, from the top head 102 to the nozzle tip 104, the fuel injector 100 includes an electrical connector 106, a manifold 108, an actuator assembly 110 including a first control valve 112 and a second control valve 114, a body 116, a barrel 118, and a nozzle 120. The fuel injector 100 also includes an upper cap nut 122 and a lower cap nut 124. The upper cap nut 122 connects the manifold 108 to the body 116 at a shoulder 161, such that the actuator assembly 110 is held between the manifold 108 and the body 116. The upper cap nut 122 is screwed onto the body 116. The lower cap nut 124 connects the body 116 to the nozzle 120, such that the barrel 118 is held between the body 116 and the nozzle 120. The lower cap nut 124 is screwed onto the body 116.

[0022] Electrical connector 106 is shaped as a complementary connector for receiving command units (not shown). Electrical connector 106 is disposed on the top of manifold 108. Electrical connector 106 includes electrical pins 126 (…). Figure 3 As shown in the figure), electrical lead 128 ( Figure 2 (As shown in the figure) Extends from the electrical pin and is arranged in specific holes provided in the manifold 108 and the first control valve 112 and the second control valve 114.

[0023] The body 116 includes a first inlet 130 arranged to receive first fuel F1 within the fuel injector 100. The nozzle 120 includes a set of first discharge orifices H1 arranged to selectively receive the first fuel F1 from the first inlet 130. The fuel injector 100 houses a first conduit L1 ( Figure 10C The first conduit (shown as a high-pressure channel) is used to deliver first fuel F1 from the first inlet 130 to the nozzle end 104, where the first fuel F1 is directly injected into the combustion chamber 58 via a set of first discharge holes H1. The first conduit L1 includes a plurality of high-pressure channels P1, which will be described in more detail later.

[0024] The manifold 108 includes a second inlet 132 arranged to receive second fuel F2 within the fuel injector 100. The nozzle 120 also includes a set of second discharge orifices H2 arranged to selectively receive second fuel F2 from the second inlet 132. The fuel injector 100 also accommodates a second conduit L2 ( Figure 6A and Figure 10CAs shown), the second pipeline is used to deliver the second fuel F2 from the second inlet 132 to the nozzle end 104, where the second fuel F2 is directly injected into the combustion chamber 58 via a set of second discharge holes H2.

[0025] In some embodiments, each of the second discharge holes H2 in a set is arranged to be aligned with a corresponding hole H1 in a set of first discharge holes H1. In some embodiments, each of the second discharge holes H2 in a set is arranged to discharge a second fuel F2 between two adjacent holes H1 in a set of first discharge holes H1.

[0026] The fuel injector 100 also includes a first valve needle 134 and a second valve needle 136, respectively arranged to control the injection of a first fuel F1 and a second fuel F2. Figure 3 In the exemplary embodiment shown, each of the first valve needle 134 and the second valve needle 136 extends along the longitudinal axis LA1 of the injector. However, in other embodiments, the first valve needle 134 and the second valve needle 136 may be concentrically arranged off-center from the longitudinal axis LA1 of the injector and / or arranged adjacent to each other. Each of the first valve needle 134 and the second valve needle 136 is movably received within the nozzle 120. The second valve needle 136 is... Figure 3 The first valve needle 134 is a hollow needle adapted to open or close a set of first discharge orifices H1 disposed at the nozzle end 104 of the fuel injector 100. The second valve needle 136 is a flat or inner needle adapted to open or close a set of second discharge orifices H2 disposed at the nozzle end 104 of the fuel injector 100.

[0027] The fuel injector 100 also includes a first control chamber 138 and a second control chamber 140 associated with a first valve needle 134 and a second valve needle 136, respectively. The nozzle 120 defines the second control chamber 140. The fuel injector 100 also includes a plug 142 disposed at the end of the second valve needle 136 remote from a set of second discharge orifices H2. The plug 142 seals the orifices surrounding the second valve needle 136. The second control chamber 140 is defined between the tip of the second valve needle 136 and the plug 142. The fuel injector 100 also includes a second spring 146 disposed between the plug 142 and the second valve needle 136. The second spring 146 biases the second valve needle 136 into a closed position of the set of second discharge orifices H2.

[0028] The cylinder 118 defines a first control chamber 138. The first control chamber 138 is a cylindrical recess disposed within the cylinder 118 above the first valve needle 134. The fuel injector 100 also includes a first spring 144 disposed between the top surface of the first control chamber 138 and the plug 142. The first spring 144 biases the first valve needle 134 into a closed position of a set of first discharge ports H1.

[0029] Figure 5 This is a perspective view of actuator assembly 110. (Reference) Figures 3 to 5 The actuator assembly 110 extends axially along the actuator longitudinal axis LA2 from the upper surface 148 to the opposite lower surface 150. The first control valve 112 includes a first valve body 152 defining the upper surface 148 of the actuator assembly 110. In other words, the first control valve 112 is formed on the upper surface 148 of the actuator assembly 110. The first valve body 152 includes corresponding components for operation of the first control valve 112, including a solenoid (not shown), an armature 1522, and a valve core 1524 (in...). Figure 4 (Best shown in the diagram). The second control valve 114 includes a second valve body 154 that defines a lower surface 150 of the actuator assembly 110. In other words, the second control valve 114 has the lower surface 150 of the actuator assembly 110 formed thereon. The second valve body 154 includes corresponding components for operation of the second control valve 114, including a solenoid, an armature, and a valve spool (not shown for illustrative purposes).

[0030] A manifold 108 is disposed on the actuator assembly 110. The manifold 108 includes a bottom surface 158 that at least partially contacts the upper surface 148 of the actuator assembly 110 at a manifold-actuator interface 160. A body 116 is disposed adjacent to the actuator assembly 110 opposite to the manifold 108. The body 116 extends axially along the injector longitudinal axis LA1 from an upper body surface 166 to an opposing lower body surface 168. The body 116 at least partially accommodates the actuator assembly 110. The body 116 includes a recess 170 disposed at the upper body surface 166 and at least partially receiving a second control valve 114 therein.

[0031] The first control valve 112 of the actuator assembly 110 is arranged to change the pressure of the control fluid in the first control chamber 138 to cause the first valve needle 134 to open and close along the longitudinal axis LA1 of the injector. In some embodiments, the second fuel F2 is the control fluid. The fuel injector 100 defines a first control path 155 (in... Figure 3 and Figure 10C(As shown in the diagram) to deliver control fluid to a first control chamber 138. When the pressure of the control fluid in the first control chamber 138 drops below a first threshold, a first valve needle 134 rises to open a set of first discharge ports H1. The first control valve 112 can be controlled to change the pressure of the control fluid in the first control chamber 138 based on application requirements. In some embodiments, the first control valve 112 is a two-way valve, while in other embodiments, the first control valve 112 is a three-way valve. In operation, a two-way valve typically produces a higher volume of fluid discharged compared to a three-way valve because the high-pressure control fluid is continuously supplied to the control chamber rather than blocked (as in a three-way valve), although in a two-way valve, the high-pressure control fluid is supplied to the control chamber under restriction more slowly than the control fluid leaves for discharge.

[0032] The second control valve 114 of the actuator assembly 110 is arranged to change the pressure of the control fluid in the second control chamber 140 to cause the second valve needle 136 to open and close along the longitudinal axis LA1 of the injector. The fuel injector 100 defines a second control path 156 (in Figure 10C (As shown in the diagram) to deliver control fluid to the second control chamber 140. When the pressure of the control fluid in the second control chamber 140 drops below a second threshold, the second valve needle 136 rises to open a set of second discharge ports H2. The second control valve 114 can be controlled to change the pressure of the control fluid in the second control chamber 140 based on application requirements. In some embodiments, the second control valve 114 is a three-way valve. In embodiments having a first control valve 112 as a two-way valve and a second control valve 114 as a three-way valve, the first control valve 112 may have a relatively high fluid volume to manage.

[0033] Figure 6A yes Figure 2 A side view of the manifold 108 of the fuel injector 100, with some of the internal components shown in dashed lines. Figure 6B This is a front view of the manifold 108, with some of its internal components shown in dashed lines. Figure 7A This is a partial front view of the manifold 108 and the actuator assembly 110. Figure 7B This is a top view of the first control valve 112 of the actuator assembly 110, with multiple return channels 164 (discharge channels) of the manifold 108 superimposed for reference.

[0034] refer to Figures 3 to 7BThe manifold 108 also includes a return inlet 162 extending through the manifold 108 from the manifold-actuator interface 160. The return inlet 162 is configured to selectively fluidly communicate with the first control chamber 138, such that it selectively receives control fluid from the first control valve 112 and the first control chamber 138. The return inlet 162 is adapted to receive control fluid from the first control chamber 138 at least via a first control path 155.

[0035] The manifold 108 also includes a plurality of return channels 164, which are angularly spaced from each other about the actuator longitudinal axis LA2. The plurality of return channels 164 are in fluid communication with a return inlet 162 above the bottom surface 158 of the manifold 108. Each of the plurality of return channels 164 is inclined relative to the actuator longitudinal axis LA2. Each return channel 164 extends downward from the return inlet 162 through the manifold 108 to the bottom surface 158. Each return channel 164 is arranged to receive control fluid from the return inlet 162. In some embodiments, the plurality of return channels 164 are radially spaced from each other in a generally uniform manner about the actuator longitudinal axis LA2 and are angularly separated from each other. Figure 7A and Figure 7B In the illustrated embodiment, the plurality of return channels 164 include a pair of return channels 164 that are angularly separated by approximately 180 degrees. Therefore, the pair of return channels 164 are configured to be diametrically opposed to each other relative to the actuator longitudinal axis LA2. Figure 7B (As best shown in the image). Figure 7A and Figure 7B The first control valve seat 1526, the discharge port supply part 1527, and the first control valve gasket 1528 are also shown.

[0036] Figure 8 This is a top view of a portion of the manifold 108' and actuator assembly 110 of a fuel injector 100' according to another embodiment of the present disclosure, with the return channel 164 of the manifold 108' superimposed for reference. The fuel injector 100' is substantially similar to... Figure 3 and Figure 4 The fuel injector 100, wherein identical parts are designated by the same reference numerals. Furthermore, the manifold 108' of the fuel injector 100' is substantially similar to... Figure 7B The manifold 108 is shown. However, in the manifold 108', the plurality of return channels 164 include three return channels that are angled apart by approximately 120 degrees. Therefore, refer to Figure 7B and Figure 8The plurality of return channels 164 may include a pair of return channels 164 spaced approximately 180 degrees apart, or three return channels 164 spaced approximately 120 degrees apart. In other embodiments, the plurality of return channels 164 may include more than three return channels 164.

[0037] Refer again Figures 3 to 7B The actuator assembly 110 also includes a plurality of arcuate protrusions 172 disposed at the periphery 175 of the upper surface 148 and angularly spaced from each other about the longitudinal axis LA2 of the actuator. Each of the plurality of arcuate protrusions 172 contacts the bottom surface 158 of the manifold 108, such that an axial clearance G1 is formed between the bottom surface 158 of the manifold 108 and the upper surface 148 of the first control valve 112 of the actuator assembly 110. The axial clearance G1 is arranged to receive control fluid from a plurality of return channels 164.

[0038] The first control valve 112 of the actuator assembly 110 also includes a plurality of ports 174. Each of the plurality of ports 174 is defined between a corresponding pair of arcuate protrusions 172. Each port 174 is arranged to receive control fluid from an axial clearance G1. A cap nut 122 defines an upper annular space 176 surrounding the actuator assembly 110. The upper annular space 176 is in fluid communication with the plurality of ports 174 of the actuator assembly 110. The upper annular space 176 is arranged to receive control fluid through the plurality of ports 174. Figure 7B In the illustrated embodiment, the plurality of ports 174 includes six ports 174. In other embodiments, the plurality of ports 174 may include four, five, seven, or any other number of ports 174.

[0039] Multiple return channels 164 allow for a more uniform distribution of control fluid on the upper surface 148 of the first control valve 112 and better distribution of control fluid to each port 174. In conventional fuel injectors, control fluid may not be distributed to each port but may instead discharge toward a single port, thus clogging that single port. In the fuel injector 100, because the multiple return channels 164 are arranged to distribute control fluid to each port 174, the high-speed flow of control fluid from the return inlet 162 to the multiple return channels 164 via the multiple ports 174 to the upper annular space 176 results in lower pressure imbalance and reduced pressure reflection. In other words, the control fluid flows efficiently from the return inlet 162 to the upper annular space 176.

[0040] The diversion of control fluid flow from return inlet 162 to multiple return channels 164 mitigates pressure reflections caused by uneven distribution of control fluid as it flows upward into the annular space 176. This, in turn, provides improved injection timing and fuel quantity, thereby improving injector performance. The multiple return channels 164 also reduce the velocity of the control fluid from return inlet 162, resulting in an effective distribution of control fluid on the upper surface 148 of actuator assembly 110. The reduced velocity of the control fluid further reduces pressure fluctuations caused by the flow of control fluid from return inlet 162 to the upper annular space 176. Therefore, there is a minimum undesirable back pressure and / or uneven fluid force acting on the upper surface 148 of actuator assembly 110 that could otherwise affect the opening and closing of the first valve needle 134 and the second valve needle 136 controlled by actuator assembly 110. Similarly, multiple return channels 164, multiple bow-shaped protrusions 172, and multiple ports 174 can also be installed in hydraulically actuated single-fuel injectors or single-needle injectors, and produce essentially similar advantages in improved injector performance, especially for gaseous fuels injected into the internal combustion chamber under high pressure.

[0041] Figure 9 yes Figure 2 A partial sectional side view of the cylinder 118 and body 116 of the fuel injector 100. Figure 10A This is a side view of cylinder 118. Figure 10B This is the front view of cylinder 118. Figure 10C This is a top view of cylinder 118. (Refer to the previous text.) Figures 3 to 10C Cylinder 118 extends axially from upper cylinder surface 178 to opposite lower cylinder surface 180. The upper cylinder surface 178 of cylinder 118 at least partially contacts the lower body surface 168 of body 116 at body-cylinder interface 182. Cylinder 118 includes an annular outer surface 184 extending between the upper cylinder surface 178 and the lower cylinder surface 180 (also...). Figure 10A (As shown in the image).

[0042] The nozzle 120 is configured to be adjacent to the cylinder 118 opposite to the body 116 and to at least partially contact the lower cylinder surface 180 of the cylinder 118. The fuel injector 100 also includes a first discharge passage 186a and a second discharge passage 186b spaced apart from the first discharge passage 186a. The first discharge passage 186a is configured to be in fluid communication with the return inlet 162 of the manifold 108. The first discharge passage 186a includes a first discharge inlet 187a arranged to receive control fluid. Figure 3 (shown in the figure) and a first discharge outlet 188a arranged to discharge control fluid from the fuel injector 100 (shown in the figure) Figure 9 (As shown in the diagram). The second discharge passage 186b includes a second discharge inlet 187b arranged to receive control fluid from at least the second control chamber 140 and the second control valve 114. Figure 3 (shown in the figure) and a second exhaust outlet 188b arranged to discharge control fluid from the fuel injector 100. Figure 9 (As shown in the image).

[0043] The first discharge channel 186a extends through the main body 116, across the main body-cylinder interface 182, and along the annular outer surface 184 of the cylinder 118, such that the first discharge outlet 188a of the first discharge channel 186a is located below the upper cylinder surface 178 and on the annular outer surface 184 of the cylinder 118. The second discharge channel 186b extends through the main body 116, across the main body-cylinder interface 182, and along the annular outer surface 184 of the cylinder 118, such that the second discharge outlet 188b of the second discharge channel 186b is located below the upper cylinder surface 178 and on the annular outer surface 184 of the cylinder 118.

[0044] A first discharge inlet 187a is formed in the main body 116 and configured to be in fluid communication with the upper annular space 176. Therefore, the first discharge inlet 187a receives control fluid from the upper annular space 176. Figure 3 and Figure 9 In the illustrated embodiment, the fuel injector 100 includes two exhaust channels (i.e., a first exhaust channel 186a and a second exhaust channel 186b). However, in some other embodiments, the fuel injector 100 may include more than two exhaust channels, and in other embodiments (such as a single fuel injector and / or a single needle injector), the fuel injector 100 may include a single exhaust channel (i.e., the first exhaust channel 186a).

[0045] In some embodiments, the first discharge channel 186a includes a first borehole channel 190a extending through the body 116 from the upper body surface 166 to the lower body surface 168. The first borehole channel 190a of the first discharge channel 186a forms a first discharge inlet 187a at the upper body surface 166, such that the first discharge inlet 187a is in fluid communication with the upper annular space 176. Therefore, the first borehole channel 190a of the first discharge channel 186a is arranged to receive control fluid from the upper annular space 176 via the first discharge inlet 187a.

[0046] In some embodiments, the second discharge passage 186b may optionally include a second borehole passage 190b extending through the body 116 from the upper body surface 166 to the lower body surface 168. In some embodiments, a second discharge inlet 187b is formed in the body 116 and configured to be in fluid communication with the upper annular space 176. In this case, the second borehole passage 190b of the second discharge passage 186b forms the second discharge inlet 187b at the upper body surface 166, such that the second discharge inlet 187b is in fluid communication with the upper annular space 176. Therefore, the second borehole passage 190b of the second discharge passage 186b is arranged to receive control fluid from the upper annular space 176 via the second discharge inlet 187b. In other embodiments, the second discharge passage 186b extends through the body 116 from the upper body surface 166 (at the lower surface 150 of the second control valve 114) to the lower body surface 168 and is not in fluid communication with the upper annular space 176.

[0047] In some embodiments, the first discharge channel 186a may extend through the body 116 such that the first discharge channel 186a does not cross the body-cylinder interface 182. In this case, the first discharge outlet 188a is located above the upper cylinder surface 178. In some embodiments, the second discharge channel 186b may extend through the body 116 such that the second discharge channel 186b does not cross the body-cylinder interface 182. In this case, the second discharge outlet 188b is located above the upper cylinder surface 178.

[0048] In some embodiments, the cylinder 118 further includes a first notch 192a and a second notch 192b spaced apart from the first notch 192a. The first notch 192a forms a portion of a first discharge channel 186a in the cylinder 118. The first notch 192a extends from an upper cylinder surface 178 along an annular outer surface 184 of the cylinder 118 and forms a first discharge outlet 188a below the upper cylinder surface 178. The first notch 192a is configured to be in fluid communication with a first borehole channel 190a of the first discharge channel 186a and is arranged to receive control fluid from the first borehole channel 190a at the body-cylinder interface 182.

[0049] The second notch 192b forms a portion of the second discharge channel 186b within the cylinder 118. The second notch 192b extends along the annular outer surface 184 of the cylinder 118 from the upper cylinder surface 178 and forms a second discharge outlet 188b below the upper cylinder surface 178. The second notch 192b is configured to be in fluid communication with the second discharge channel 186b and is arranged to receive control fluid from the second discharge channel 186b at the body-cylinder interface 182. Figure 10C As shown, in some embodiments, each of the first notch 192a and the second notch 192b has a semi-circular cross section in a plane perpendicular to the longitudinal axis LA1 of the injector.

[0050] By extending the first exhaust outlet 188a of the first exhaust channel 186a and the second exhaust outlet 188b of the second exhaust channel 186b below the upper cylinder surface 178 and on the annular outer surface 184 of the cylinder 118, pressure fluctuations and pressure reflections in the first exhaust channel 186a and the second exhaust channel 186b are reduced compared to conventional injectors where the exhaust channels only extend to the upper cylinder surface. The pressure fluctuations and pressure reflections in the first exhaust channel 186a and the second exhaust channel 186b are minimized, which could otherwise affect the fuel supply accuracy of the injector 100.

[0051] Figure 11A This is a side perspective view of the lower cover nut 124. Figure 11B This is a side sectional view of the lower cover nut 124. (Reference) Figure 3 and Figures 9 to 11B The lower cover nut 124 includes a first outlet hole 194a extending through the lower cover nut. The lower cover nut 124 also includes a second outlet hole 194b extending through the lower cover nut and angularly spaced from the first outlet hole 194a about the longitudinal axis LA1 of the injector. The lower cover nut 124 defines a lower annular space 196 surrounding the cylinder 118. Figure 9 (As shown in the figure). The lower annular space 196 is configured to be in fluid communication with each of the first outlet orifice 194a and the second outlet orifice 194b.

[0052] Furthermore, the lower annular space 196 is configured to be in fluid communication with the first exhaust outlet 188a and arranged to receive control fluid from the first exhaust passage 186a. The first outlet orifice 194a is arranged to receive control fluid from the lower annular space 196 and to deliver control fluid from the fuel injector 100. The lower annular space 196 is configured to be in fluid communication with the second exhaust outlet 188b and arranged to receive control fluid from the second exhaust passage 186b. The second outlet orifice 194b is arranged to receive control fluid from the lower annular space 196 and to deliver control fluid from the fuel injector 100. Figure 3 , Figure 9 and Figure 11A In the illustrated embodiment, the lower cap nut 124 includes two outlet holes (i.e., a first outlet hole 194a and a second outlet hole 194b). However, in other embodiments, the lower cap nut 124 may include more than two outlet holes. Control fluid can be returned to the liquid tank via the first outlet hole 194a and the second outlet hole 194b. Although in Figure 3 and Figure 9The first outlet port 194a and the second outlet port 194b are shown aligned with the first discharge channel 188a and the second discharge channel 188b, respectively, but this is not necessary, and the first outlet port 194a and the second outlet port 194b may be circumferentially spaced up to 90 degrees from the corresponding first discharge channel 188a and the second discharge channel 188b.

[0053] Compared to a fuel injector with a single outlet orifice for discharging control fluid from the fuel injector, a fuel injector 100 with two outlet orifices (i.e., a first outlet orifice 194a and a second outlet orifice 194b) formed in the lower cover nut 124 experiences minimal pressure reflection caused by the flow of control fluid in the first discharge channel 186a and the second discharge channel 186b, thereby improving the consistency of the pressure of the control fluid in the first discharge channel 186a and the second discharge channel 186b and maintaining the desired flow rate of the control fluid in the first discharge channel 186a and the second discharge channel 186b.

[0054] Refer again Figure 10C The fuel injector 100 also includes a sealing fluid supply line arranged to seal a plurality of high-pressure channels P1 at least at the body-cylinder interface 182 to prevent leakage of first fuel F1 from the plurality of high-pressure channels P1. The pressure of the liquid sealing fluid should be sufficient to prevent leakage of first fuel F1 from the high-pressure channels P1. In some embodiments, the sealing fluid supply line includes a liquid sealing fluid. In some embodiments, the liquid sealing fluid is a second fuel F2. When the liquid sealing fluid is the second fuel F2, the first fuel F1 (i.e., within the high-pressure channels P1) is pressurized to a pressure slightly less than that of the second fuel F2 (i.e., liquid fuel) to prevent leakage of the first fuel as it passes through the fluid-sealed chamber in the fuel injector 100.

[0055] Figure 12A According to an embodiment of the present disclosure Figure 2 A side perspective view of the first line L1 in the fuel injector 100. Figure 12B This is a rear view of the first conduit, L1. (Reference) Figure 3 , Figure 10C , Figure 12A and Figure 12B The nozzle 120 also includes a plenum interface 198 arranged to selectively receive first fuel F1 from the first inlet 130. The plenum interface 198 is in fluid communication with a set of first discharge ports H1. In other words, the set of first discharge ports H1 receives the first fuel F1 from the plenum interface 198.

[0056] As already mentioned, the fuel injector 100 includes a plurality of high-pressure channels P1 extending from a first inlet 130 to a chamber junction 198. A first conduit L1 extends from the first (main fuel) inlet 130 in a single short section, which branches off to form the plurality of high-pressure channels P1. The plurality of high-pressure channels P1 extend downward through the body 116 and the cylinder 118 before entering the nozzle 120. Figure 12A and Figure 12B In the illustrated embodiment, the high-pressure first conduit L1 is divided into two, and then four, high-pressure channels P1. In other embodiments, depending on application requirements and the availability of space in the fuel injector 100, the multiple high-pressure channels P1 may include three, five, or any other number of high-pressure channels P1.

[0057] Figure 13 It is shown in Figure 12A Figure 202 shows the relationship between the total cross-sectional flow area A1 of the first conduit L1 extending from the high-pressure main fuel inlet 130 (i.e., the first inlet 130) to the chamber junction 198, and the length S1 of the high-pressure first (main fuel) conduit L1. The total cross-sectional flow area A1 of the first conduit L1 is the sum of the cross-sectional flow areas of each of the plurality of high-pressure channels P1 at a specific section length S1 measured based on the first inlet 130. The length S1 is expressed in arbitrary units on the horizontal axis. The total cross-sectional flow area A1 is expressed in arbitrary units on the vertical axis.

[0058] In some embodiments, the total cross-sectional flow area A1 of the first conduit L1 decreases or remains substantially the same along its length S1 from the first inlet 130 to the chamber junction 198. Furthermore, the cross-sectional flow area of ​​each high-pressure channel P1 decreases or remains substantially the same along its length S1 from the first inlet 130 to the chamber junction 198. Figure 12A As shown, the cross-sectional flow area of ​​each high-pressure channel P1 gradually decreases along its length S1 with multiple steps 200 from the first inlet 130 to the chamber junction 198. This ensures that when high-pressure fuel flows from the high-pressure main fuel inlet 130 to the chamber junction 198, i.e., as... Figure 13 As shown, when moving downstream from the high-pressure fuel inlet 130, which is plotted on the left side of the length S1 abscissa, to the chamber junction 198, which is plotted on the right side of the length S1 abscissa, the total cross-sectional flow area A1 of the first pipeline L1 remains substantially constant, and then the total cross-sectional flow area A1 decreases at the step 200.

[0059] The decreasing cross-sectional flow area of ​​each high-pressure channel P1 along its length S1 from the first inlet 130 to the chamber junction 198 provides additional space for the discharge channels (i.e., the first discharge channel 186a and the second discharge channel 186b) to extend below the upper cylinder surface 178 before exiting the cylinder 118. The additional space provided by the reduced cross-sectional flow area of ​​each high-pressure channel P1 can also be used to accommodate various fluid channels, such as those for supplying additives.

[0060] As the first fuel F1 flows downstream from the first inlet 130 to the chamber junction 198, the reduced cross-sectional flow area of ​​each high-pressure channel P1 and the reduced total cross-sectional flow area A1 of the first conduit L1 result in reduced pressure reflections and pressure waves in the fluid passages of the first conduit L1 in the fuel injector 100 during operation. The reduced cross-sectional flow area of ​​each high-pressure channel P1 also allows for higher pressures to be achieved in the first conduit L1 without increasing the size of the fuel injector 100. Therefore, the reduced cross-sectional flow area of ​​each high-pressure channel P1 and the reduced total cross-sectional flow area A1 of the first conduit L1 as the first fuel F1 flows downstream from the first inlet 130 to the chamber junction 198 provide improved performance of the fuel injector 100 related to the injection timing and opening / closing rate of the first valve needle 134 and the second valve needle 136.

[0061] refer to Figures 1 to 13 The fuel injector 100 includes various features such as multiple return channels 164, multiple bow-shaped protrusions 172, multiple ports 174, a first discharge channel 186a, a second discharge channel 186b, a first notch 192a, a second notch 192b, a first outlet orifice 194a, and a second outlet orifice 194b. These features of the fuel injector 100 help reduce pressure fluctuations and pressure reflections in the fluid passages (i.e., the discharge channels) and in the interface regions where the injector components connect to each other. When pressure fluctuations and pressure reflections are reduced or eliminated, the control of fluid pressure within the injector is improved, along with the timing and opening / closing rate of the first valve needle 134 and the second valve needle 136, resulting in more precise timing of fuel injection, effective control of injection events, and minimization or reduction of fluid leakage from its respective fluid passages within the fuel injector 100. Because the amount and timing of fuel delivered to combustion chamber 58 affect the torque output of internal combustion engine 50, reduced pressure fluctuations in the exhaust passage of fuel injector 100, alone or in combination with reduced pressure waves in first line L1, provide improved injector performance and the desired torque output of internal combustion engine 50. Improved timing of injection of first fuel F1 and second fuel F2 also results in improved exhaust emissions from internal combustion engine 50.

[0062] Alternatively, in some embodiments, the fuel injector 100 may be a single-fuel injector and / or a single-needle injector adapted to inject fuel from a single fuel passage. For example, in some embodiments, the fuel injector 100 may not include the second valve needle 136 and other features associated with the second valve needle 136 (such as the second control chamber 140, a set of second discharge ports H2, the second control valve 114, the second spring 146, and the associated passage). In this case, the first valve needle 134 does not need to be hollow, but may remain hollow to reduce the mass of the first valve needle.

[0063] While specific elements, embodiments, and applications of the invention have been shown and described, it will be understood that the invention is not limited thereto, as modifications can be made by those skilled in the art without departing from the scope of this disclosure, particularly in light of the foregoing teachings.

Claims

1. A fuel injector for an internal combustion engine, the fuel injector comprising: A first valve needle, arranged to control the injection of a first fuel, extends along the longitudinal axis of the injector; A first control room, which is associated with the first valve needle; An actuator assembly extending axially from an upper surface to an opposite lower surface along an actuator longitudinal axis, the actuator assembly including a first control valve arranged to change the pressure of a control fluid in a first control chamber to cause an opening and closing movement of a first valve needle along the injector longitudinal axis; A manifold, disposed on the actuator assembly, the manifold including a bottom surface and a return inlet, the bottom surface at least partially contacting the upper surface of the actuator assembly at the manifold-actuator interface, the return inlet extending from the manifold-actuator interface through the manifold, wherein the return inlet is configured to selectively fluidly communicate with the first control chamber such that the return inlet selectively receives the control fluid from the first control chamber; A body, the body being configured to be adjacent to the actuator assembly relative to the manifold and extending axially from an upper body surface to an opposite lower body surface, the body at least partially accommodating the actuator assembly; A cylinder extending axially from an upper cylinder surface to an opposing lower cylinder surface, the cylinder including an annular outer surface extending between the upper cylinder surface and the lower cylinder surface, wherein the upper cylinder surface of the cylinder at least partially contacts the lower body surface of the body at a body-cylinder interface; A nozzle, the nozzle being configured to be adjacent to the cylinder relative to the body and to at least partially contact the lower cylinder surface of the cylinder; and A first discharge channel is configured to be in fluid communication with the return inlet of the manifold. The first discharge channel includes a first discharge inlet arranged to receive the control fluid and a first discharge outlet arranged to discharge the control fluid. The first discharge channel extends through the body, across the body-cylinder interface, and along the annular outer surface of the cylinder, such that the first discharge outlet of the first discharge channel is located below the upper cylinder surface and on the annular outer surface of the cylinder.

2. The fuel injector according to claim 1, wherein, The manifold also includes a plurality of return channels spaced at an angle to each other about the longitudinal axis of the actuator and in fluid communication with the return inlet above the bottom surface of the manifold, wherein each of the plurality of return channels is inclined relative to the longitudinal axis of the actuator and extends downward from the return inlet through the manifold to the bottom surface, and wherein each return channel is arranged to receive the control fluid from the return inlet.

3. The fuel injector according to claim 2, wherein, The plurality of return channels are radially spaced from each other in a generally uniform manner around the longitudinal axis of the actuator and are angularly separated from each other.

4. The fuel injector according to claim 2, wherein, The plurality of return channels include a pair of return channels that are angled apart by approximately 180 degrees, or three return channels that are angled apart by approximately 120 degrees.

5. The fuel injector according to claim 2, wherein, The actuator assembly further includes: A plurality of arcuate protrusions are disposed around the periphery of the upper surface and angularly spaced from each other about the longitudinal axis of the actuator. Each of the arcuate protrusions contacts the bottom surface of the manifold, such that an axial gap is formed between the bottom surface of the manifold and the upper surface of the actuator assembly, wherein the axial gap is arranged to receive the control fluid from the plurality of return channels; and Multiple ports, wherein each port is defined between a corresponding pair of bow-shaped protrusions among the multiple bow-shaped protrusions and arranged to receive the control fluid from the axial gap.

6. The fuel injector of claim 5, further comprising a cap nut that connects the manifold to the body, such that the actuator assembly is held between the manifold and the body, wherein, The top cover nut defines an upper annular space surrounding the actuator assembly, the upper annular space being in fluid communication with the plurality of ports of the actuator assembly and arranged to receive the control fluid through the plurality of ports, wherein the first discharge inlet is formed in the body and configured to be in fluid communication with the upper annular space.

7. The fuel injector according to claim 6, wherein, The first discharge channel includes a first borehole channel extending through the body from the upper body surface to the lower body surface, wherein the first borehole channel of the first discharge channel forms the first discharge inlet at the upper body surface, such that the first discharge inlet is in fluid communication with the upper annular space.

8. The fuel injector according to claim 7, wherein, The cylinder further includes a first notch forming a portion of the first discharge channel within the cylinder, wherein the first notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms the first discharge outlet below the upper cylinder surface, and wherein the first notch is configured to be in fluid communication with the first borehole channel of the first discharge channel and arranged to receive the control fluid from the first borehole channel at the body-cylinder interface.

9. The fuel injector of claim 8, further comprising a lower cap nut that connects the body to the nozzle, such that the cylinder is held between the body and the nozzle, wherein, The lower cover nut includes a first outlet hole extending through the lower cover nut, wherein the lower cover nut defines a lower annular space surrounding the cylinder, the lower annular space being configured to be in fluid communication with the first outlet hole, the lower annular space being in fluid communication with a first discharge outlet and being arranged to receive the control fluid from the first discharge passage, and wherein the first outlet hole is arranged to receive the control fluid from the lower annular space and to deliver the control fluid from the fuel injector.

10. The fuel injector according to claim 9, further comprising: A second valve needle, arranged to control the injection of a second fuel, extends along the longitudinal axis of the injector; as well as A second control room, which is associated with the second valve needle; The actuator assembly further includes a second control valve, which is arranged to change the pressure of the control fluid in the second control chamber to cause the second valve needle to open and close along the longitudinal axis of the injector.

11. The fuel injector of claim 10, further comprising a second discharge passage spaced apart from the first discharge passage, the second discharge passage including a second discharge inlet arranged to receive the control fluid from at least the second control chamber and a second discharge outlet arranged to discharge the control fluid, wherein, The second discharge channel extends through the body, across the body-cylinder interface and along the annular outer surface of the cylinder, such that the second discharge outlet is located below the upper cylinder surface and on the annular outer surface of the cylinder.

12. The fuel injector according to claim 11, wherein, The second discharge inlet is formed in the main body and configured to be in fluid communication with the upper annular space.

13. The fuel injector according to claim 11, wherein, The second discharge channel includes a second borehole channel extending through the body from the upper body surface to the lower body surface, wherein the second borehole channel of the second discharge channel forms a second discharge inlet at the upper body surface, such that the second discharge inlet is in fluid communication with the upper annular space.

14. The fuel injector according to claim 11, wherein, The cylinder further includes a second notch spaced apart from the first notch and forming a portion of the second discharge channel in the cylinder, wherein the second notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms a second discharge outlet below the upper cylinder surface, and wherein the second notch is configured to be in fluid communication with the second discharge channel and arranged to receive the control fluid from the second discharge channel at the body-cylinder interface.

15. The fuel injector according to claim 14, wherein, Each of the first notch and the second notch has a semi-circular cross-section in a plane perpendicular to the longitudinal axis of the injector.

16. The fuel injector according to claim 14, wherein, The lower cover nut includes a second outlet hole extending through the lower cover nut and angularly spaced from the first outlet hole about the longitudinal axis of the injector. The lower annular space is configured to communicate with the second outlet hole and the second exhaust outlet, and the lower annular space is arranged to receive the control fluid from the second exhaust passage. The second outlet hole is arranged to receive the control fluid from the lower annular space and deliver the control fluid from the fuel injector.

17. The fuel injector according to claim 10, wherein, Each of the first valve needle and the second valve needle is movably received within the nozzle.

18. The fuel injector according to claim 10, wherein, The second valve needle is concentrically guided in a hole located inside the first valve needle.

19. The fuel injector according to claim 10, wherein, The nozzle defines the second control chamber.

20. The fuel injector according to claim 10, wherein, The first control valve forms the upper surface of the actuator assembly, and the second control valve forms the lower surface of the actuator assembly.

21. The fuel injector according to claim 10, wherein, The body includes a recess disposed on the upper body surface and at least partially receiving the second control valve within the recess.

22. The fuel injector according to claim 10, wherein, The manifold further includes a second inlet arranged to receive the second fuel within the fuel injector, and wherein the nozzle further includes a set of second discharge orifices arranged to selectively receive the second fuel from the second inlet.

23. The fuel injector according to claim 22, wherein, The second fuel is the control fluid.

24. The fuel injector according to claim 23, wherein, The second fuel is a liquid fuel.

25. The fuel injector according to claim 22, wherein, The body further includes a first inlet arranged to receive the first fuel within the fuel injector, and wherein the nozzle further includes a chamber junction and a set of first discharge orifices, the chamber junction being arranged to selectively receive the first fuel from the first inlet, the set of first discharge orifices being configured to be in fluid communication with the chamber junction.

26. The fuel injector of claim 25, further comprising a plurality of high-pressure channels extending from the first inlet to the chamber junction, wherein, The cross-sectional flow area of ​​each of the plurality of high-pressure channels decreases or remains substantially the same along the length of the high-pressure channel from the first inlet to the chamber junction.

27. The fuel injector according to claim 26, wherein, The cross-sectional flow area of ​​each high-pressure channel gradually decreases in multiple steps along the length of the high-pressure channel from the first inlet to the chamber junction.

28. The fuel injector of claim 26, further comprising a sealed fluid supply line arranged to seal the plurality of high-pressure channels at least at the body-cylinder interface to prevent leakage of the first fuel from the plurality of high-pressure channels.

29. The fuel injector according to claim 28, wherein, The sealing fluid supply line includes a liquid sealing fluid.

30. The fuel injector according to claim 29, wherein, The liquid sealing fluid is the second fuel.

31. The fuel injector according to claim 25, wherein, Each hole in the set of second discharge holes is arranged to be aligned with a corresponding hole in the set of first discharge holes.

32. The fuel injector according to claim 25, wherein, Each of the second set of discharge holes is arranged to discharge the second fuel between two adjacent holes in the first set of discharge holes.

33. The fuel injector according to any of the preceding claims, wherein, The first fuel is a gaseous fuel.

34. The fuel injector according to claim 33, wherein, The gaseous fuel is hydrogen.

35. The fuel injector according to any of the preceding claims, wherein, The cylinder defines the first control room.

36. A fuel injector for an internal combustion engine, the fuel injector comprising: A first valve needle, arranged to control the injection of a first fuel, extends along the longitudinal axis of the injector; A first control room, which is associated with the first valve needle; An actuator assembly extending axially from an upper surface to an opposite lower surface along an actuator longitudinal axis, the actuator assembly including a first control valve arranged to change the pressure of a control fluid in a first control chamber to cause an opening and closing movement of a first valve needle along the injector longitudinal axis; as well as A manifold body, disposed on the actuator assembly, includes a bottom surface, a return inlet, and multiple return channels. The bottom surface at least partially contacts the upper surface of the actuator assembly at the manifold-actuator interface. The return inlet extends from the manifold-actuator interface through the manifold, wherein the return inlet is configured to selectively fluidly communicate with the first control chamber, such that the return inlet selectively receives the control fluid from the first control chamber. The plurality of return channels are spaced at an angle to each other about the longitudinal axis of the actuator and are in fluid communication with the return inlet above the bottom surface of the manifold, wherein each of the plurality of return channels is inclined relative to the longitudinal axis of the actuator and extends downward from the return inlet through the manifold to the bottom surface, wherein each return channel is arranged to receive the control fluid from the return inlet.

37. The fuel injector according to claim 36, wherein, The plurality of return channels are radially spaced from each other in a generally uniform manner around the longitudinal axis of the actuator and are angularly separated from each other.

38. The fuel injector according to claim 36, wherein, The plurality of return channels include a pair of return channels that are angled apart by approximately 180 degrees, or three return channels that are angled apart by approximately 120 degrees.

39. The fuel injector according to claim 36, wherein, The actuator assembly further includes: A plurality of arcuate protrusions are disposed around the periphery of the upper surface and angularly spaced from each other about the longitudinal axis of the actuator. Each of the arcuate protrusions contacts the bottom surface of the manifold, such that an axial gap is formed between the bottom surface of the manifold and the upper surface of the actuator assembly, wherein the axial gap is arranged to receive the control fluid from the plurality of return channels; and Multiple ports, wherein each port is defined between a corresponding pair of bow-shaped protrusions among the multiple bow-shaped protrusions and arranged to receive the control fluid from the axial gap.

40. The fuel injector of claim 39, further comprising a first discharge passage configured to be in fluid communication with the return inlet of the manifold, the first discharge passage including a first discharge inlet arranged to receive the control fluid and a first discharge outlet arranged to discharge the control fluid.

41. The fuel injector of claim 40, further comprising: A body, the body being configured to be adjacent to the actuator assembly relative to the manifold and extending axially from an upper body surface to an opposite lower body surface, the body at least partially accommodating the actuator assembly; A cylinder extending axially from an upper cylinder surface to an opposing lower cylinder surface, the cylinder including an annular outer surface extending between the upper and lower cylinder surfaces, wherein the upper cylinder surface of the cylinder at least partially contacts the lower body surface of the body at a body-cylinder interface; and A nozzle, the nozzle being configured to be adjacent to the cylinder relative to the body and to at least partially contact the lower cylinder surface of the cylinder; The first discharge channel extends through the body, across the body-cylinder interface, and along the annular outer surface of the cylinder, such that the first discharge outlet of the first discharge channel is located below the upper cylinder surface and on the annular outer surface of the cylinder.

42. The fuel injector of claim 41, further comprising a cap nut that connects the manifold to the body, such that the actuator assembly is held between the manifold and the body, wherein, The top cover nut defines an upper annular space surrounding the actuator assembly, the upper annular space being in fluid communication with the plurality of ports of the actuator assembly and arranged to receive the control fluid through the plurality of ports, wherein the first discharge inlet is formed in the body and configured to be in fluid communication with the upper annular space.

43. The fuel injector according to claim 42, wherein, The first discharge channel includes a first borehole channel extending through the body from the upper body surface to the lower body surface, wherein the first borehole channel of the first discharge channel forms the first discharge inlet at the upper body surface, such that the first discharge inlet is in fluid communication with the upper annular space.

44. The fuel injector according to claim 43, wherein, The cylinder further includes a first notch forming a portion of the first discharge channel within the cylinder, wherein the first notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms the first discharge outlet below the upper cylinder surface, and wherein the first notch is configured to be in fluid communication with the first borehole channel of the first discharge channel and arranged to receive the control fluid from the first borehole channel at the body-cylinder interface.

45. The fuel injector of claim 44, further comprising a lower cap nut that connects the body to the nozzle, such that the cylinder is held between the body and the nozzle, wherein, The lower cover nut includes a first outlet hole extending through the lower cover nut, wherein the lower cover nut defines a lower annular space surrounding the cylinder, the lower annular space being configured to be in fluid communication with the first outlet hole, the lower annular space being in fluid communication with a first discharge outlet and being arranged to receive the control fluid from the first discharge passage, and wherein the first outlet hole is arranged to receive the control fluid from the lower annular space and to deliver the control fluid from the fuel injector.

46. ​​The fuel injector of claim 45, further comprising: A second valve needle, arranged to control the injection of a second fuel, extends along the longitudinal axis of the injector; as well as A second control room, which is associated with the second valve needle; The actuator assembly further includes a second control valve, which is arranged to change the pressure of the control fluid in the second control chamber to cause the second valve needle to open and close along the longitudinal axis of the injector.

47. The fuel injector of claim 46, further comprising a second discharge passage spaced apart from the first discharge passage, the second discharge passage including a second discharge inlet arranged to receive the control fluid from at least the second control chamber and a second discharge outlet arranged to discharge the control fluid, wherein, The second discharge channel extends through the body, across the body-cylinder interface and along the annular outer surface of the cylinder, such that the second discharge outlet is located below the upper cylinder surface and on the annular outer surface of the cylinder.

48. The fuel injector according to claim 47, wherein, The second discharge inlet is formed in the main body and configured to be in fluid communication with the upper annular space.

49. The fuel injector according to claim 47, wherein, The second discharge channel includes a second borehole channel extending through the body from the upper body surface to the lower body surface, wherein the second borehole channel of the second discharge channel forms a second discharge inlet at the upper body surface, such that the second discharge inlet is in fluid communication with the upper annular space.

50. The fuel injector according to claim 47, wherein, The cylinder further includes a second notch spaced apart from the first notch and forming a portion of the second discharge channel in the cylinder, wherein the second notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms a second discharge outlet below the upper cylinder surface, and wherein the second notch is configured to be in fluid communication with the second discharge channel and arranged to receive the control fluid from the second discharge channel at the body-cylinder interface.

51. The fuel injector according to claim 50, wherein, Each of the first notch and the second notch has a semi-circular cross-section in a plane perpendicular to the longitudinal axis of the injector.

52. The fuel injector according to claim 50, wherein, The lower cover nut includes a second outlet hole extending through the lower cover nut and angularly spaced from the first outlet hole about the longitudinal axis of the injector. The lower annular space is configured to communicate with the second outlet hole and the second exhaust outlet, and the lower annular space is arranged to receive the control fluid from the second exhaust passage. The second outlet hole is arranged to receive the control fluid from the lower annular space and deliver the control fluid from the fuel injector.

53. The fuel injector according to claim 46, wherein, Each of the first valve needle and the second valve needle is movably received within the nozzle.

54. The fuel injector according to claim 46, wherein, The second valve needle is concentrically guided in a hole located inside the first valve needle.

55. The fuel injector according to claim 46, wherein, The nozzle defines the second control chamber.

56. The fuel injector according to claim 46, wherein, The first control valve forms the upper surface of the actuator assembly, and the second control valve forms the lower surface of the actuator assembly.

57. The fuel injector according to claim 46, wherein, The body includes a recess disposed on the upper body surface and at least partially receiving the second control valve within the recess.

58. The fuel injector according to claim 46, wherein, The manifold further includes a second inlet arranged to receive the second fuel within the fuel injector, and wherein the nozzle further includes a set of second discharge orifices arranged to selectively receive the second fuel from the second inlet.

59. The fuel injector according to claim 58, wherein, The second fuel is the control fluid.

60. The fuel injector according to claim 59, wherein, The second fuel is a liquid fuel.

61. The fuel injector according to claim 58, wherein, The body further includes a first inlet arranged to receive the first fuel within the fuel injector, and wherein the nozzle further includes a chamber junction and a set of first discharge orifices, the chamber junction being arranged to selectively receive the first fuel from the first inlet, the set of first discharge orifices being configured to be in fluid communication with the chamber junction.

62. The fuel injector of claim 61, further comprising a plurality of high-pressure channels extending from the first inlet to the chamber junction, wherein, The cross-sectional flow area of ​​each of the plurality of high-pressure channels decreases or remains substantially the same along the length of the high-pressure channel from the first inlet to the chamber junction.

63. The fuel injector according to claim 62, wherein, The cross-sectional flow area of ​​each high-pressure channel gradually decreases in multiple steps along the length of the high-pressure channel from the first inlet to the chamber junction.

64. The fuel injector of claim 62, further comprising a sealed fluid supply line arranged to seal the plurality of high-pressure channels at least at the body-cylinder interface to prevent leakage of the first fuel from the plurality of high-pressure channels.

65. The fuel injector according to claim 64, wherein, The sealing fluid supply line includes a liquid sealing fluid.

66. The fuel injector according to claim 65, wherein, The liquid sealing fluid is the second fuel.

67. The fuel injector according to claim 61, wherein, Each hole in the set of second discharge holes is arranged to be aligned with a corresponding hole in the set of first discharge holes.

68. The fuel injector according to claim 61, wherein, Each of the second set of discharge holes is arranged to discharge the second fuel between two adjacent holes in the first set of discharge holes.

69. The fuel injector according to any one of claims 36 to 68, wherein, The first fuel is a gaseous fuel.

70. The fuel injector according to claim 69, wherein, The gaseous fuel is hydrogen.

71. The fuel injector according to claim 41, wherein, The cylinder defines the first control room.

72. A fuel injector for an internal combustion engine, the fuel injector comprising: A first valve needle, arranged to control the injection of a first fuel, extends along the longitudinal axis of the injector; A first control room, which is associated with the first valve needle; An actuator assembly extending axially from an upper surface to an opposite lower surface along an actuator longitudinal axis, the actuator assembly including a first control valve arranged to change the pressure of a control fluid in a first control chamber to cause an opening and closing movement of a first valve needle along the injector longitudinal axis; as well as A body, the body being disposed adjacent to the actuator assembly and extending axially from an upper body surface to an opposing lower body surface, the body at least partially accommodating the actuator assembly, the body including a first inlet, the first inlet being arranged to receive the first fuel within the fuel injector; A cylinder extending axially from an upper cylinder surface to an opposing lower cylinder surface, the cylinder including an annular outer surface extending between the upper cylinder surface and the lower cylinder surface, wherein the upper cylinder surface of the cylinder at least partially contacts the lower body surface of the body at a body-cylinder interface; A nozzle configured to be adjacent to the cylinder and at least partially in contact with the lower cylinder surface of the cylinder, the nozzle including a chamber junction and a set of first discharge orifices, the chamber junction being arranged to selectively receive the first fuel from the first inlet, the set of first discharge orifices being configured to be in fluid communication with the chamber junction; and A plurality of high-pressure channels extend from the first inlet to the chamber junction, wherein the cross-sectional flow area of ​​each of the plurality of high-pressure channels decreases or remains substantially the same along the length of the high-pressure channel from the first inlet to the chamber junction.

73. The fuel injector according to claim 72, wherein, The cross-sectional flow area of ​​each high-pressure channel gradually decreases in multiple steps along the length of the high-pressure channel from the first inlet to the chamber junction.

74. The fuel injector of claim 72, further comprising a manifold disposed on the actuator assembly, the manifold comprising: The bottom surface at least partially contacts the upper surface of the actuator assembly at the manifold-actuator interface; A return inlet, extending from the manifold-actuator interface through the manifold, wherein the return inlet is configured to selectively fluidly communicate with the first control chamber, such that the return inlet selectively receives the control fluid from the first control chamber; and A plurality of return channels are spaced at an angle to each other about the longitudinal axis of the actuator and are in fluid communication with the return inlet above the bottom surface of the manifold, wherein each of the plurality of return channels is inclined relative to the longitudinal axis of the actuator and extends downward from the return inlet through the manifold to the bottom surface, wherein each return channel is arranged to receive the control fluid from the return inlet.

75. The fuel injector according to claim 74, wherein, The plurality of return channels are radially spaced from each other in a generally uniform manner around the longitudinal axis of the actuator and are angularly separated from each other.

76. The fuel injector according to claim 74, wherein, The plurality of return channels include a pair of return channels that are angled apart by approximately 180 degrees, or three return channels that are angled apart by approximately 120 degrees.

77. The fuel injector according to claim 74, wherein, The actuator assembly further includes: A plurality of arcuate protrusions are disposed around the periphery of the upper surface and angularly spaced from each other about the longitudinal axis of the actuator. Each of the arcuate protrusions contacts the bottom surface of the manifold, such that an axial gap is formed between the bottom surface of the manifold and the upper surface of the actuator assembly, wherein the axial gap is arranged to receive the control fluid from the plurality of return channels; and Multiple ports, wherein each port is defined between a corresponding pair of bow-shaped protrusions among the multiple bow-shaped protrusions and arranged to receive the control fluid from the axial gap.

78. The fuel injector of claim 77, further comprising a first discharge passage configured to be in fluid communication with the return inlet of the manifold, the first discharge passage including a first discharge inlet arranged to receive the control fluid and a first discharge outlet arranged to discharge the control fluid, wherein, The first discharge channel extends through the body, across the body-cylinder interface and along the annular outer surface of the cylinder, such that the first discharge outlet of the first discharge channel is located below the upper cylinder surface and on the annular outer surface of the cylinder.

79. The fuel injector of claim 78, further comprising a cap nut that connects the manifold to the body, such that the actuator assembly is held between the manifold and the body, wherein, The top cover nut defines an upper annular space surrounding the actuator assembly, the upper annular space being in fluid communication with the plurality of ports of the actuator assembly and arranged to receive the control fluid through the plurality of ports, wherein the first discharge inlet is formed in the body and configured to be in fluid communication with the upper annular space.

80. The fuel injector according to claim 79, wherein, The first discharge channel includes a first borehole channel extending through the body from the upper body surface to the lower body surface, wherein the first borehole channel of the first discharge channel forms the first discharge inlet at the upper body surface, such that the first discharge inlet is in fluid communication with the upper annular space.

81. The fuel injector according to claim 80, wherein, The cylinder further includes a first notch forming a portion of the first discharge channel within the cylinder, wherein the first notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms the first discharge outlet below the upper cylinder surface, and wherein the first notch is configured to be in fluid communication with the first borehole channel of the first discharge channel and arranged to receive the control fluid from the first borehole channel at the body-cylinder interface.

82. The fuel injector of claim 81, further comprising a lower cap nut that connects the body to the nozzle, such that the cylinder is held between the body and the nozzle, wherein, The lower cover nut includes a first outlet hole extending through the lower cover nut, wherein the lower cover nut defines a lower annular space surrounding the cylinder, the lower annular space being configured to be in fluid communication with the first outlet hole, the lower annular space being in fluid communication with a first discharge outlet and being arranged to receive the control fluid from the first discharge passage, and wherein the first outlet hole is arranged to receive the control fluid from the lower annular space and to deliver the control fluid from the fuel injector.

83. The fuel injector according to claim 82, further comprising: A second valve needle, arranged to control the injection of a second fuel, extends along the longitudinal axis of the injector; as well as A second control room, which is associated with the second valve needle; The actuator assembly further includes a second control valve, which is arranged to change the pressure of the control fluid in the second control chamber to cause the second valve needle to open and close along the longitudinal axis of the injector.

84. The fuel injector of claim 83, further comprising a second discharge passage spaced apart from the first discharge passage, the second discharge passage including a second discharge inlet arranged to receive the control fluid from at least the second control chamber and a second discharge outlet arranged to discharge the control fluid, wherein, The second discharge channel extends through the body, across the body-cylinder interface and along the annular outer surface of the cylinder, such that the second discharge outlet is located below the upper cylinder surface and on the annular outer surface of the cylinder.

85. The fuel injector according to claim 84, wherein, The second discharge inlet is formed in the main body and configured to be in fluid communication with the upper annular space.

86. The fuel injector according to claim 85, wherein, The second discharge channel includes a second borehole channel extending through the body from the upper body surface to the lower body surface, wherein the second borehole channel of the second discharge channel forms a second discharge inlet at the upper body surface, such that the second discharge inlet is in fluid communication with the upper annular space.

87. The fuel injector according to claim 83, wherein, The cylinder further includes a second notch spaced apart from the first notch and forming a portion of the second discharge channel in the cylinder, wherein the second notch extends from the upper cylinder surface along the annular outer surface of the cylinder and forms a second discharge outlet below the upper cylinder surface, and wherein the second notch is configured to be in fluid communication with the second discharge channel and arranged to receive the control fluid from the second discharge channel at the body-cylinder interface.

88. The fuel injector according to claim 87, wherein, Each of the first notch and the second notch has a semi-circular cross-section in a plane perpendicular to the longitudinal axis of the injector.

89. The fuel injector according to claim 87, wherein, The lower cover nut includes a second outlet hole extending through the lower cover nut and angularly spaced from the first outlet hole about the longitudinal axis of the injector. The lower annular space is configured to communicate with the second outlet hole and the second exhaust outlet, and the lower annular space is arranged to receive the control fluid from the second exhaust passage. The second outlet hole is arranged to receive the control fluid from the lower annular space and deliver the control fluid from the fuel injector.

90. The fuel injector according to claim 83, wherein, Each of the first valve needle and the second valve needle is movably received within the nozzle.

91. The fuel injector according to claim 83, wherein, The second valve needle is concentrically guided in a hole located inside the first valve needle.

92. The fuel injector according to claim 83, wherein, The nozzle defines the second control chamber.

93. The fuel injector according to claim 83, wherein, The first control valve forms the upper surface of the actuator assembly, and the second control valve forms the lower surface of the actuator assembly.

94. The fuel injector according to claim 83, wherein, The body includes a recess disposed on the upper body surface and at least partially receiving the second control valve within the recess.

95. The fuel injector according to claim 83, wherein, The manifold further includes a second inlet arranged to receive the second fuel within the fuel injector, and wherein the nozzle further includes a set of second discharge orifices arranged to selectively receive the second fuel from the second inlet.

96. The fuel injector according to claim 95, wherein, The second fuel is the control fluid.

97. The fuel injector according to claim 96, wherein, The second fuel is a liquid fuel.

98. The fuel injector of claim 95, further comprising a sealed fluid supply line arranged to seal the plurality of high-pressure channels at least at the body-tube interface to prevent leakage of the first fuel from the plurality of high-pressure channels.

99. The fuel injector according to claim 98, wherein, The sealing fluid supply line includes a liquid sealing fluid.

100. The fuel injector according to claim 99, wherein, The liquid sealing fluid is the second fuel.

101. The fuel injector according to claim 95, wherein, Each hole in the set of second discharge holes is arranged to be aligned with a corresponding hole in the set of first discharge holes.

102. The fuel injector according to claim 95, wherein, Each of the second set of discharge holes is arranged to discharge the second fuel between two adjacent holes in the first set of discharge holes.

103. The fuel injector according to any one of claims 72 to 102, wherein, The first fuel is a gaseous fuel.

104. The fuel injector according to claim 103, wherein, The gaseous fuel is hydrogen.

105. The fuel injector according to any one of claims 72 to 104, wherein, The cylinder defines the first control room.

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