Fuel injection device with reduced pressure in the armature cavity

Abstract

A fuel injection device for an engine is disclosed. The fuel injection device may comprise a fuel nozzle with at least one injection metering port, and further a needle element which is movable within the fuel nozzle between a first position in which the needle element prevents fuel flow, and a second position in which the fuel flow is substantially unobstructed. The fuel injection device may also comprise a control chamber located at a base end of the needle element, a body, and a control valve which is arranged within the body and is movable to selectively drain the control chamber, thereby causing the needle element to move between the first and second positions.The fuel injection device may further have an armature located within an armature cavity of the body and selectively excited to move the control valve, and a pressure reduction device located within the body and configured to reduce the pressure of the armature cavity.

Description

Technical field

[0001] The present disclosure relates to a fuel injection device, and in particular to a fuel injection device with a reduced pressure in the armature cavity. background

[0002] Common-rail fuel injection systems provide a means of introducing fuel from a common supply line into the combustion chambers of an engine. Typically, common-rail fuel injection systems have an actuating solenoid that opens a control valve, which regulates the fuel pressure on one side of a check valve. When the pressure on the check valve drops, the check valve begins to lift, and fuel injection begins. When the pressure on the check valve rises, the check valve closes, and fuel injection ends. Similarly, fuel is injected as a function of the time period during which the solenoid's armature is energized. An example of such a fuel injection system is disclosed in US Patent 7,013,876 B1 by Puckett and Others, granted on March 21, 2006.

[0003] Reference is also made to US 8,523,090 B2, which discloses a housing for a fuel injector armature, a fuel injector, and a fuel injection system. The armature housing comprises a first cylindrical section for the sliding reception of the armature pin. The first cylindrical section has a minimum inner diameter that is precisely matched to the maximum outer diameter of the armature pin. A second cylindrical section of the armature housing receives the armature. The second cylindrical section has a minimum inner diameter that is precisely matched to the maximum outer diameter of the armature.

[0004] A common problem associated with common-rail fuel injection systems is known as injector bounce. Injector bounce, or jolts, can occur when the control valve closes rapidly and jumps from its associated seat. When the control valve jumps from its seat, a delay in its closing is created, which can lead to a delayed end of injection and / or the injection of additional fuel. This injection delay and these additional injections can reduce engine efficiency and cause unstable engine operation.

[0005] The fuel injection device of the present disclosure addresses one or more of the problems set out above and / or other problems of the prior art. Summary

[0006] The object of the present invention is achieved by a fuel injection device according to claim 1 and by a method for injecting fuel according to claim 8. The dependent claims relate to preferred embodiments of the invention.

[0007] One aspect of the present disclosure relates to an insert for use with an anchor assembly. The insert may have a top surface configured to fluidically communicate with a cavity of the anchor assembly, a bottom surface opposite the top surface configured to engage with a wall of the anchor assembly, and a central bore extending from the top surface to the bottom surface configured to receive a pin of the anchor assembly. The insert may also have a first passage formed at least partially within the bottom surface, comprising an effusor or inlet portion, a neck portion, and a diffuser or outlet portion; and a second passage extending from the neck portion to the top surface.

[0008] Another aspect of the present disclosure relates to an anchor arrangement. The anchor arrangement may comprise a body with an anchor cavity, an anchor arranged in the anchor cavity, and an insert arranged in the anchor cavity. The insert may have at least part of a Venturi arrangement formed within it, configured to reduce pressure in the anchor cavity.

[0009] A further aspect of the present disclosure relates to a fuel injection device. The fuel injection device may have a fuel nozzle with at least one metering orifice, and a needle element having a tip end and a base end. The needle element may be movable within the fuel nozzle between a first position in which the tip end of the needle element prevents fuel flow through the at least one metering orifice, and a second position in which fuel flow through the at least one metering orifice is substantially not obstructed by the tip end of the needle element. The fuel injection device may also have a control chamber located at the base end of the needle element, a body, and a control valve arranged within the body and movable to selectively drain or empty the control chamber.to empty, causing the needle element to move between the first and second positions. The fuel injection device may further include an armature located within an armature cavity of the body and selectively energized to move the control valve, and a pressure-reducing device located within the body and configured to reduce the pressure of the armature cavity.

[0010] Another aspect of the present disclosure relates to a method for injecting fuel. The method may include directing high-pressure fuel into a nozzle of a fuel injection device and directing low-pressure coolant into an anchor cavity of the fuel injection device. The method may further include exciting an anchor within the anchor cavity to allow high-pressure fuel to be discharged from the nozzle and reducing the pressure of the low-pressure coolant within the anchor cavity below a boiling point. Brief description of the drawings Fig. Figure 1 is a partially cross-sectional and schematic illustration of an exemplary disclosed fuel system; Fig. 2 is a cross-sectional view of an exemplary disclosed fuel injection device, which is used in the fuel system of the Fig. 1 can be used; Fig. Figure 3 is a cross-sectional illustration of part of the fuel injection device of the Fig. 2; Fig. Figure 4 is another cross-sectional illustration of part of the fuel injection device of the Fig. 2; and Fig. Figure 5 is a pictorial representation of an application of the fuel injection device of the Fig. 2. Detailed description

[0011] Fig. Figure 1 illustrates an engine 10 and an exemplary embodiment of a fuel system 12. For the purposes of this disclosure, the engine 10 is depicted and described as a four-stroke diesel engine. However, the person skilled in the art will recognize that the engine 10 can be any other type of internal combustion engine, such as an engine powered by gasoline or liquefied gaseous fuel. The engine 10 can have an engine block 14 defining a plurality of cylinders 16, a piston 18 arranged in each cylinder 16, and a cylinder head 20 associated with each cylinder 16.

[0012] The cylinder 16, the piston 18, and the cylinder head 20 can together form a combustion chamber 22. In the illustrated embodiment, the engine 10 has six combustion chambers 22. However, it is considered that the engine 10 may have a larger or smaller number of combustion chambers 22, and that the combustion chambers 22 may be arranged in an in-line configuration, a V-configuration, or any other suitable configuration.

[0013] As also in Fig. As shown in Figure 1, the engine 10 can have a crankshaft 24 which is rotatably arranged within the engine block 14. A connecting rod 26 can connect each piston 18 to the crankshaft 24, so that a sliding movement of the piston 18 within each respective cylinder 16 results in a rotation of the crankshaft 24. Similarly, a rotation of the crankshaft 24 can result in a sliding movement of the piston 18.

[0014] The fuel system 12 can include components that work together to deliver injections of pressurized fuel into the combustion chambers 22 during each rotation of the crankshaft 24. In particular, the fuel system 12 can include a tank 28 configured to contain a fuel supply or reservoir, and a fuel pump assembly 30 configured to pressurize the fuel and deliver the pressurized fuel to a plurality of fuel injection devices 32 via a common rail or common pressure line 34.

[0015] The fuel pump assembly 30 can have one or more pump devices that increase the pressure of the fuel drawn from the tank 28 and that direct one or more pressurized fuel streams to the common rail 34. In one example, the pump assembly 30 has a low-pressure source 36 and a high-pressure source 38 arranged in series and fluidically connected by a fuel line 40. The low-pressure source 36 can be a transfer pump or pilot pump configured to provide a low-pressure feed to the high-pressure source 38 and, for cooling purposes, directly to the fuel injectors 32. The high-pressure source 38 can be connected to the fuel injectors 32 by means of a fuel line 41.The high-pressure source 38 can be configured to receive the low-pressure feed and increase the fuel pressure to a range of approximately 30–300 MPa. The high-pressure source 38 can be connected to the common rail 34 via a fuel line 42. The check valve 44 can be located within the fuel line 42 to allow a one-way flow of fuel from the fuel pump assembly 30 to the common rail 34.

[0016] The low-pressure source 36 and / or the high-pressure source 38 can be operationally connected to the motor 10 and driven by the crankshaft 24. The low-pressure source 36 and / or the high-pressure source 38 can be connected to the crankshaft 24 in any way that is readily apparent to a person skilled in the art, such that a rotation of the crankshaft 24 will result in a corresponding rotation of the pump drive shaft. For example, a pump drive shaft 46 of the high-pressure source 38 is connected in Fig. 1 shown such that it is connected to the crankshaft 24 by a gear train 48. However, it is considered that the low-pressure source 36 and / or the high-pressure source 38 could alternatively be driven electrically, hydraulically, pneumatically, or in any other suitable manner.

[0017] The fuel injection devices 32 can be arranged within the cylinder heads 20 and connected to the common rail 34 by a plurality of fuel lines 50 and to the tank 28 by a drain line 51. Each fuel injection device 32 can be operated to inject a quantity of pressurized fuel into an associated combustion chamber 22 at predetermined times, with predetermined fuel pressures, and with predetermined fuel flow rates. The timing of the fuel injection into the combustion chamber 22 can be synchronized with the movement of the piston 18. For example, the fuel can be injected as the piston 18 approaches top dead center in a compression stroke to allow compression-ignition or compression-ignition combustion of the injected fuel.Alternatively, fuel can be injected when piston 18 begins its compression stroke as it moves towards top dead center for HCCI (homogeneous compression-ignited charge) operation. Fuel can also be injected when piston 18 moves from top dead center to bottom dead center during an expansion stroke for late post-injection to create a reducing atmosphere for post-treatment regeneration.

[0018] As in Fig. As illustrated in Figure 2, each fuel injection device 32 can be a unit fuel injection device or a pump-nozzle fuel injection device with a closed nozzle. In particular, each fuel injection device 32 can have a body 52, a nozzle housing 54 which is operationally connected to the injection device body 52, and a guide 56, further comprising a sleeve 58 and a nozzle 60 which is arranged at least partially within the nozzle housing 54. The fuel injection device 32 can also have a needle element 62 which is located within the nozzle 60, and an electromagnetic actuating device 64 which is arranged within the body 52 at an end of the injection device 32 which is opposite the nozzle 60.It is considered that additional components could be provided within the fuel injection device 32, such as pressure equalization passages, accumulators and other injection device components known in the art.

[0019] The injection device body 52 can be a cylindrical element configured to be mounted within the cylinder head 20 and which has one or more passages. In the disclosed embodiment, the injection device body 52 has a central bore 66 configured to accommodate the electromagnetic actuating device 64, a low-pressure fuel inlet 68, a low-pressure fuel outlet 70, and a high-pressure fuel inlet 72. However, it is considered that additional, fewer, and / or different passages may be provided in the injection device body 52 if desired.The low-pressure fuel inlet 68 can extend radially inward from the fuel line 41 to the central bore 66 to supply the electromagnetic actuator 64 with low-pressure fuel, which acts as a coolant to cool the electromagnetic actuator 64 during operation. The low-pressure fuel outlet 70 can extend radially outward from the central bore 66 at a point closer to the nozzle 60 than the low-pressure fuel inlet 68, to an outer cylindrical surface of the body 52, to direct warmer fuel to the discharge line 51. The high-pressure fuel inlet 72 can extend from the outer cylindrical surface of the body 52 to an axial interface with the guide 56.

[0020] The nozzle housing 54 can be a cylindrical element with a central bore 74, configured to accommodate the guide 56, the sleeve 58, and the nozzle 60. The nozzle housing 54 can also have an opening 76 through which a tip end 78 of the nozzle 60 protrudes.

[0021] The guide 56 can be a cylindrical element axially aligned with the body 52 and arranged within the nozzle housing 54, specifically between the body 52 and the sleeve 58. The guide 56 can have an internally formed control chamber 80, which is in direct connection with a base end of the needle element 62 and radially offset with respect to the high-pressure fuel passage 82, which connects the high-pressure fuel inlet 72 to the sleeve 58. Pressurized fuel can be selectively discharged from or supplied to the control chamber 80 to control the reciprocating movement of the needle element 62. In the disclosed embodiment, one or more metering orifice plates 84, 86 can be arranged between the guide 56 and the body 52, if desired.The metering orifice plates 84, 86 can have a common control passage 88 extending from the central bore 66 of the body 52 to the control chamber 80, and a common high-pressure passage 90 extending from the high-pressure inlet 72 of the body 52 to the high-pressure fuel passage 82 within the guide 56.

[0022] The sleeve 58 can also be a cylindrical link with a central bore 92 configured to accommodate the needle element 62 and a return spring 94. The return spring 94 can be positioned between a stop 96 and an end seat 98 of the guide 56 to axially bias the needle element 62 towards the tip 78 of the nozzle 60. A spacer 100 can be positioned between the return spring 94 and the stop 96 to reduce wear of the components within the fuel injection device 32 and / or to adjust the load or preload of the return spring 94, if desired.

[0023] The nozzle 60 can similarly embody a cylindrical element and have a central bore 102 configured to receive the needle element 62. A space between the walls of the central bore 102 and the needle element 62 can form a pressure chamber containing a supply or reservoir of pressurized fuel drawn in by the high-pressure passage 82 in preparation for an injection event. The nozzle 60 can also have one or more metering ports 104 that allow pressurized fuel to flow from the pressure chamber and into the combustion chambers 22 of the engine 10 when the needle element 62 is moved away from the metering ports 104.

[0024] The needle element 62 can be an elongated cylindrical segment slidably arranged within the guide 56, the sleeve 58, and the nozzle 60. The needle element 62 can be axially movable between a first position in which a tip end of the needle element 62 essentially blocks the flow of fuel through the metering ports 104, and a second position in which the metering ports 104 are open to allow a flow of fuel into the combustion chamber 22. It is considered that the needle element 62 is a multi-part or multi-segmented element comprising a needle segment and a piston segment, or a single element having an integral piston surface at its base end, as desired.

[0025] The needle element 62 can have multiple hydraulic drive surfaces. For example, the needle element 62 can have a first hydraulic surface 106 and a second hydraulic surface 108. The first hydraulic surface 106 can tend to drive the needle element 62 to a first position, or metering port locking position, with the preload of the return spring 94 when pressurized fuel acts upon it. The second hydraulic surface 108 can tend to act against the preload of the return spring 94 and drive the needle element 62 in the opposite direction to a second position, or metering port opening position, when pressurized fuel acts upon it.

[0026] The electromagnetic actuator 64 can be arranged at an end of the injection device 62 opposite the nozzle 60 to control the forces acting on the needle element 62. In particular, the electromagnetic actuator 64 can have windings 110 of a suitable shape and size through which current can flow to generate a magnetic field, and an armature 112 associated with the windings 110. The armature 112 can be rigidly connected to a two-position armature pin 114 within a cavity 116, and when the windings 110 are energized, the magnetic field generated by the windings 110 can push the armature 112 and the associated armature pin 114 against the bias of a return spring 116 from a first position, or non-injection position, to a second position, or injection position.For example, the anchor pin 114 can be moved between a lower seat 118 and an upper seat 120.

[0027] When the windings 110 are not energized, the spring 116 can move the armature pin 114 into the non-injection position (i.e. downwards against the lower seat 118, as shown in Fig. (2 shown), and fuel can flow from the high-pressure fuel inlet 72 through the passage 90 and into the control chamber 80 via a (not shown) transversely drilled radial passage. The pressurized fuel within the control chamber 80 can generate a downward force on the hydraulic surface 106, which, in combination with the force of the return spring 94, acts to overcome any upward force on the hydraulic surface 108 and move the needle element 62 to close the metering ports 104 and terminate fuel injection. When the windings 110 are energized, fuel can flow from the control chamber 80 to the tank 28 via the passage 88, the central bore 66, and the low-pressure fuel outlet 70.When fuel flows from the control chamber 80 to the tank 28, the upward force of the pressurized fluid acting on the hydraulic surface 108 can push the needle element 62 against the return spring 94, thereby opening the metering ports 104 and initiating fuel injection into the combustion chambers 22. Subsequently, when the windings 110 are de-energized, the return spring 116 can return the armature pin 114 to the non-injection position. In this way, the timing and the level of the induced current within the windings 110 can be controlled to influence the fuel injection.

[0028] The electromagnetic actuating device 64 can also be provided with an insert 122, which simultaneously acts as a pressure-reducing device for the armature cavity 115, further with a holder for the spring 116 and with a guide for the armature 112. As shown in Fig. As shown in Figure 3, the insert 122 can generally have a top surface 124 oriented towards the anchor 112 when installed, and a bottom surface 126 located opposite the top surface 124. The insert 122 can also have a projection 128 extending away from the bottom surface 126 to engage with the spring 116, thereby holding the spring 116 in a position within the central bore 66 of the body 52. ​​A smaller central bore 130 can extend from the top surface 124 through the projection 128 and can be configured to slide in and receive the anchor pin 114. An air gap spacer 131, located on a circumference of the anchor cavity 115, can press against the top surface 124, thereby holding the insert 122 in place against a shoulder 133 of the central bore 66.

[0029] The insert 122, together with the shoulder 133, can form a Venturi element 132 at the interface of the insert 122 and the shoulder 133. In particular, the insert 122 can have grooves within the underside 126, which, together with the shoulder 133, form a passage with an effusor or inlet part 134, a diffuser or outlet part 136, and a neck part 138 located between the effusor part 134 and the diffuser part 136 (i.e., the Venturi arrangement 132 can be partially formed by both the inlet 122 and the shoulder 133). As shown in Fig. As can be seen in Figure 3, both the effusor part 134 and the diffuser part 136 can have gradually decreasing heights near the neck part 138 (for example, in a curved line, as in Figure 3). Fig. 3 or angled as in the Fig. 4 and Fig. 5) In the disclosed embodiment, the effusor part 134 can have a larger inlet opening cross-section (i.e., greater height and width) and a shorter length than the outlet opening cross-section and outlet opening length of the diffuser part 136, whereby this relationship can result in a greater pressure drop at the neck part 138. The effusor part 134 can be fluidically connected to the low-pressure fuel inlet 68, while the diffuser part 136 can be fluidically connected to the low-pressure outlet 70. Accordingly, the low-pressure fuel can flow from the inlet 68 into the effusor part 134, through the neck part 138, where the fuel flow is restricted, causing the fuel velocity to increase, into the diffuser part 136, and out of the injection device 32 via the low-pressure outlet 70.The inlet 122 can also have an axial passage 140 extending from the top 124 of the inlet 122 to the throat section 138. In this configuration, the fuel flow from the Venturi device 132 can generate a low pressure within the passage 140, which has the effect of reducing the pressure within the armature cavity 115.

[0030] The insert 122 can have any number of Venturi devices 132 and axial passages 140 arranged around the projection 128. For example, the insert 122 is the Fig. 3 shown such that it has two different Venturi devices 132 and two different passages 140, each pair of Venturi device 132 and passage 140 being located on one side of the projection 128. In this configuration, the Venturi device 132 can have a shorter overall length than the radius of the inlet 122. In the exemplary embodiment of Fig. 4 and Fig. Figure 5, however, illustrates only a single Venturi arrangement 132 and a single passage 140. In this configuration, the Venturi arrangement 132 can have a greater overall length than the radius of the inlet 122. Because of the length of the Venturi arrangement 132 in the exemplary embodiment of Fig. 4 and Fig. 5 An additional passage 142 may be required to properly connect the diffuser part 136 to the low-pressure fuel outlet 70. Industrial applicability

[0031] The fuel injection device of the present disclosure is widely used in a variety of engine types, including, for example, diesel engines, gasoline engines, and engines powered by liquefied gaseous fuel. The disclosed fuel injection device can be used in conjunction with any engine where consistent performance is important. The operation of the fuel injection device 32 will now be explained.

[0032] During normal operation of the engine 10, high-pressure fuel and low-pressure fuel can be supplied to each injection device 32 by the fuel pump assembly 30 (see Fig. 1) be supplied. In particular, high-pressure fuel can be supplied through the high-pressure source 38 to the high-pressure fuel inlet 72 (see Fig. 2) via the passage 42, the common rail 34, and the fuel lines 50. High-pressure fuel can enter the fuel injection device 32 via the high-pressure fuel inlet 72 and flow through the passages 90, 82, and 92 and into the central bore 102, where the fuel awaits an injection event. Additionally, the high-pressure fuel can fill the control chamber 80 from passage 90 in preparation for an injection event. Low-pressure fuel can simultaneously be supplied as a coolant through the low-pressure source 36 to the low-pressure fuel inlet 68 via the fuel line 41. The low-pressure fuel can enter the fuel injection device 32 via the low-pressure fuel inlet 68, flow through the Venturi assembly 132 and the end of the central bore 66 near the spring 116, and exit the fuel injection device 32 via the low-pressure outlet 70.

[0033] The electromagnetic actuating device 64 can be excited to inject fuel into the combustion chambers 22 (see Fig. 1) to initiate. In particular, when an electric current is applied to the windings 110, the armature 112 and the armature pin 114 can be moved upwards away from the nozzle 60. When the armature pin 114 moves upwards, the control chamber 80 can be fluidically connected to the low-pressure outlet 70, causing the control chamber 80 to empty. At this point, the high-pressure fluid acting on the hydraulic surface 108 can overcome the preload of the spring 94, causing the needle element 62 to move upwards away from the metering ports 104 and initiating the injection event.

[0034] To terminate the injection event, the electromagnetic actuating device 64 can be de-energized or switched off, allowing the spring 116 to return the armature 112 and the armature pin 114 to their downward position until the lower seat 118 engages the armature pin 114 and the flow from the control chamber 80 is stopped. At this point, the pressure within the control chamber 80 can build up until the pressure acting on the hydraulic surface 106, together with the preload of the spring 94, is sufficient to return the needle element 62 to the flow-blocking position against the metering ports 104.

[0035] During the movement of the armature 112, pressure fluctuations can be generated within the cavity 115, causing the armature 112 to oscillate (i.e., jump) in an undesirable manner. Specifically, as the armature 112 moves downward, a flow of high-pressure fuel from the cavity 115 and below the armature 112 around the circumference of the armature 112 can be forced to an area above the armature 112. Conversely, as the armature 112 moves upward, a low-pressure area can be generated below the armature 112, drawing the high-pressure fuel back downward. Accordingly, the area below and above the armature 112 can be subject to cyclic pressure fluctuations, from low pressure to high pressure to low pressure, and so on. In conventional fuel injection devices, these pressure fluctuations do not cease immediately when the windings 110 are suddenly energized or de-energized.Instead, the pressure fluctuations decrease slowly, and as they decrease, they can cause continued back-and-forth movements of the armature 112. In some situations, the continued back-and-forth movements of the armature 112 may be sufficient to cause the needle element 62 to open the metering ports 104 when no fuel injection is desired.

[0036] However, when using the insert 122, the armature cavity 115 can be maintained at a relatively consistent low pressure by the action of the Venturi arrangement 132. That is, the flow of coolant (i.e., low-pressure fuel) through the effusor section 134, the neck section 138, and the diffuser section 136 can cause a low pressure to develop within the passage 140, which pulls the pressure down within the cavity 115. In one embodiment, the pressure can be reduced almost to the vapor pressure of the fuel, causing the fuel to boil and generate bubbles in the space between the armature 112 and the insert 122. These bubbles can act as shock absorbers to dampen unwanted pressure fluctuations and / or oscillating movements of the armature 112.

[0037] Because the insert 122 can create a damping environment for the armature 112, the probability that the needle element 62 will move sufficiently to clear the metering ports 104 after an intended injection event should have already ended can be reduced. This reduction can result in smoother and more efficient operation of the motor 10.

[0038] It will be obvious to those skilled in the art that various modifications and variations can be made to the fuel injection device of the present disclosure without deviating from the scope of the claims. Other embodiments will become apparent to those skilled in the art upon consideration of the description and a practical implementation of the fuel injection device disclosed herein.

Claims

[1] Fuel injection device (32) comprising: a fuel nozzle (60) with at least one injection metering opening (104); a needle element (62) with a tip end (78) and a base end, which within the fuel nozzle (60) between a first position, in which the tip end (78) of the needle element (62) prevents fuel flow through the at least one injection metering port (104), and is movable to a second position in which the fuel flow through the at least one injection metering port (104) is substantially not prevented by the tip end (78) of the needle element (62); a control chamber (80) located at the base end of the needle element (62); a body (52); a control valve (114) which is arranged inside the body (52) and is movable to selectively drain the control chamber (80), which causes the needle element (62) to move between the first and second positions; an anchor (112) which is arranged in an anchor cavity (115) of the body (52) and is selectively excited to move the control valve (114); and a pressure reduction device (122) which is arranged inside the body (52) and is configured to reduce the pressure of the anchor cavity (115); wherein the fuel injection device is configured to receive a high-pressure fuel for injection and a low-pressure fuel for cooling; wherein the low-pressure fuel is passed through the pressure reducing device (122); and wherein the pressure reduction device (122) has a Venturi arrangement (132) with an effusor part (134), a neck part (138) and a diffuser part (136) configured to receive low-pressure fuel and a passage extending from the armature cavity (115) to the neck part (138). [2] Fuel injection device (32) according to claim 1, wherein the pressure reduction device (122) is configured to reduce the pressure of the anchor cavity (115) to below an evaporation point of the fluid within the anchor cavity (115). [3] Fuel injection device (32) according to claim 1, wherein the pressure reduction device (122) is configured to generate bubbles within the anchor cavity (115). [4] Fuel injection device (32) according to claim 1, wherein the pressure reduction device (122) further comprises: a projection (128) configured to hold a spring (116); and a central bore (130) through the projection (1289) which is configured, to guide the control valve (114). [5] Fuel injection device (32) according to claim 1, wherein the Venturi arrangement (132) has a greater length than an outer radius of the pressure reduction device (122). [6] Fuel injection device (32) according to claim 1, wherein the Venturi arrangement (132) has a shorter length than an outer radius of the pressure reduction device (122); the Venturi arrangement (132) is a first Venturi arrangement; and The pressure reduction device (122) further comprises a second Venturi arrangement which is essentially identical to the first Venturi arrangement. [7] Fuel injection device (32) according to claim 1, wherein the Venturi arrangement (132) is located at an interface between the pressure reduction device (122) and a shoulder (133) of the anchor cavity (115); and the Venturi arrangement (132) is partially formed by the shoulder (133) of the anchor cavity (115). [8] A method for injecting fuel comprising the following: Introducing high-pressure fuel into a fuel nozzle (60) of a fuel injection device (32) according to one of the preceding claims; Introducing low-pressure coolant into an anchor cavity (115) of the fuel injection device; Excitation of an anchor (112) within the anchor cavity (115) to allow high-pressure fuel to be released from the fuel nozzle (60); and Reducing the pressure of the low-pressure coolant within the anchor cavity (115) below an evaporation point.

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