EP3150839B1 - Fuel injector - Google Patents
Fuel injector Download PDFInfo
- Publication number
- EP3150839B1 EP3150839B1 EP16190307.5A EP16190307A EP3150839B1 EP 3150839 B1 EP3150839 B1 EP 3150839B1 EP 16190307 A EP16190307 A EP 16190307A EP 3150839 B1 EP3150839 B1 EP 3150839B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- control chamber
- fuel
- moveable plate
- sealing surface
- high pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Not-in-force
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
- F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
- F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
- F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
- F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
- F02M63/0012—Valves
- F02M63/0014—Valves characterised by the valve actuating means
- F02M63/0028—Valves characterised by the valve actuating means hydraulic
- F02M63/0029—Valves characterised by the valve actuating means hydraulic using a pilot valve controlling a hydraulic chamber
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
- F02M63/0012—Valves
- F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
- F02M63/0045—Three-way valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/28—Details of throttles in fuel-injection apparatus
Definitions
- the present invention relates to a fuel injector with an improved valve control arrangement for positioning a valve needle of a fuel injector in a position whereby injection of fuel occurs, and in a position whereby injection of fuel is prevented.
- the present invention relates to a fuel injector with a valve control arrangement which utilises a moveable plate to control the flow of high pressure fuel between a high pressure fuel supply and an injection valve needle control chamber.
- valve control arrangement of this type is described in EP 1 163 440 .
- a thrust surface provided at the end of the valve needle that is distal from the valve seat can be subjected to a force resulting from pressurised fuel within the needle control chamber acting against it and a medial thrust surface provided between the distal and proximal ends of the valve needle can be subjected to a force resulting from pressurised fuel within an associated annular chamber in the nozzle body.
- Fuel from a high pressure fuel supply source can flow into the valve needle control chamber through an inlet orifice (INO) in the inlet passage.
- Fuel can flow out from the valve needle control chamber to a low pressure reservoir or drain through an outlet orifice, commonly referred to as a 'spill orifice' (SPO), when the discharge valve is opened by a solenoid actuator.
- Fuel flows into the annular chamber within the nozzle body from the high pressure fuel supply source and flows out from the chamber through injection orifices which are opened and closed as the valve needle is raised or lowered respectively.
- the discharge valve In operation, to raise the valve needle and hence open the injection orifices, the discharge valve is opened, under the direct control of the solenoid actuator.
- the fuel within the valve needle control chamber is then able to flow out to the low pressure drain via the SPO. Because the INO is present in the high pressure fuel supply line to the valve needle control chamber the pressure of the fuel within the valve needle control chamber is reduced and thus the downwards force applied to the valve needle, as a result of the fuel acting upon the distal thrust surface, is reduced. High pressure fuel is still acting on the medial thrust surface of the valve needle and the resulting upwards force applied to the valve needle thrust surface is greater than the downwards force applied to the valve needle and thus the valve needle starts to move upwards.
- the fuel within the chamber in the nozzle body flows out to an engine cylinder, which is at a relatively low pressure, and thus the fuel pressure within the annular chamber in the nozzle body reduces.
- the upwards force acting on the valve needle reduces.
- the upwards force acting on the thrust surface is still greater than the downwards force applied to the valve needle and thus the valve needle remains in a raised position and fuel injection through the injection orifices continues.
- the discharge valve In order to lower the valve needle, close the injection orifices and thus cease the injection of fuel, the discharge valve is moved to a closed position. This is achieved by stopping the supply of electrical current to the solenoid and under the direct action of a helical compression spring acting on the discharge valve member. This closes the outlet from the valve needle control chamber to the low pressure drain and thus, since high pressure fuel is still being supplied to the needle control chamber, via the INO, the pressure of fuel within the needle control chamber is raised. The downwards force applied to the valve becomes greater than the upwards force and thus the valve needle moves downwards.
- This prior art valve control arrangement utilises a hydraulically balanced discharge valve. It is necessary to use a hydraulically balanced discharge valve because a small solenoid actuator is used to control movement of the discharge valve and such an actuator is not able to generate sufficient force to close an unbalanced valve against the high pressure of the fuel within the valve needle control chamber acting against it. It is desired to use a small solenoid actuator as this enables the actuator to be placed within the body of the injector. Furthermore, there is a cost reduction associated with the use of a small actuator.
- a disadvantage of hydraulically balanced valves is that they suffer from static leak. This is leak across the discharge valve from the high pressure side, i.e. the valve needle control chamber, to the low pressure drain and is exacerbated by the high pressures and temperatures of the fuel to which the discharge valve is subjected. This static leak requires a higher pump capacity and results in wasted energy as pressurised fuel escapes to the low pressure drain.
- the prior art control arrangement suffers from dynamic fuel leakage when the valve needle is raised.
- the dynamic leakage occurs between the high pressure fuel inlet and the low pressure reservoir or drain when the discharge valve is open.
- the dynamic leakage is disadvantageous for the same reasons set forth above in respect to static leakage.
- the inlet orifice and the spill orifice are present in the valve control arrangement of the prior art to enable the greatest closing speed of the valve needle, i.e. the shortest delay between the discharge valve being closed and the pressure of fuel within the valve needle control chamber reaching a level at which the downwards force applied to the valve needle is greater than the force applied upwards, and to enable the greatest opening speed of the valve needle, i.e. the shortest delay between the discharge valve being opened and the pressure of fuel within the valve needle control chamber reducing to a level whereby the upwards force applied to the valve needle is greater than the downwards force applied to the needle.
- valve needle control chamber In order to have the greatest closing speed for the valve needle it is necessary to fill the valve needle control chamber as quickly as possible.
- the ideal situation would be to have an unrestricted fuel inlet, i.e. no inlet orifice and a heavily restricted fuel outlet, i.e. a small spill orifice.
- a high opening speed for the valve needle it is also desirable to have a high opening speed for the valve needle and this requires that the valve needle control chamber is emptied as quickly as possible through the outlet passage.
- an unrestricted fuel outlet i.e. no spill orifice and a heavily restricted fuel inlet, i.e. a small inlet orifice.
- the prior art control arrangement is limited by suffering from undesirable levels of static and dynamic leakage and from having a relatively long delay time between actuation of the discharge valve and movement of the valve needle.
- EP2628939 discloses a fuel injector corresponding to the preamble of claim 1. Another fuel injector is known from WO 03/071122 A1 and US 2010/301143 A1 .
- the present invention provides a fuel injector for an internal combustion engine, in particular a compression ignition internal combustion engine, the fuel injector comprising: a fuel injection valve having an injection valve member moveable, in use, under the influence of fuel pressure within a control chamber acting upon it, between a closed position and an open position; a high pressure fuel supply channel to the control chamber; a fuel outlet channel leading from the control chamber to a low pressure reservoir or drain; an actuator operable to open and close a discharge valve located in the fuel outlet channel; a moveable plate located in the control chamber and arranged to move into and out of contact with a sealing surface of the control chamber; a spill orifice provided in the moveable plate and arranged to communicate with the fuel outlet channel when the moveable plate is located in contact with the sealing surface of the control chamber, the spill orifice defining a restricted flow path for fuel to flow out of the control chamber to the fuel outlet channel; and an inlet orifice provided in the moveable plate and arranged to communicate with the high pressure fuel supply channel when the moveable plate is located
- inlet and spill orifices in the moveable plate enables significantly smaller inlet and outlet orifices to be used in comparison to the prior art. Consequently, the present invention results in a significant reduction of dynamic leakage as low pressure fuel flows out of the control chamber during an emptying phase of the control chamber.
- the moveable plate In use, when the moveable plate is in contact with the sealing surface of the control chamber and the discharge valve is open, fuel flows from the high pressure fuel supply channel into the control chamber through the inlet orifice in the moveable plate, and fuel flows out of the control chamber through the spill orifice in the moveable plate and through the fuel outlet channel to the low pressure reservoir or drain.
- the provision of the inlet orifice in the moveable plate therefore allows a restricted flow of fuel to enter the control chamber during the emptying phase of the control chamber.
- the relative sizes of the inlet and spill orifices can advantageously be selected to enable a smooth and controlled lifting of the injection valve member.
- the moveable plate is configured such that one or more additional fluid passages are defined between the control chamber and the high pressure fuel supply channel when the moveable plate is moved out of contact with the sealing surface of the control chamber.
- the additional fluid passages are defined at least in part by formations such as flats or grooves in a periphery of the moveable plate.
- the additional fluid passages enable fuel from the high pressure fuel supply channel to enter the control chamber bypassing the inlet orifice.
- the rate of filling of the control chamber is not governed exclusively by the size of the inlet orifice.
- the inlet orifice can therefore be made smaller without compromising the rate at which the control chamber is filled, and hence the fuel injector can terminate an injection event rapidly despite having a small inlet orifice.
- the high pressure fuel supply channel upstream of the additional fluid passage(s) is substantially unrestricted. This allows a substantially unrestricted flow of fuel to enter the control chamber via the additional fluid passages resulting in a very rapid termination of an injection event.
- the injector is configured such that, in use, when the moveable plate moves out of contact with the sealing surface of the control chamber, fuel flows from the high pressure fuel supply channel into the control chamber through the additional fluid passage(s) and through the inlet orifice and spill orifice in the moveable plate.
- a plurality of flow paths for high pressure fuel entering the control chamber are therefore provided thus allowing faster termination of an injection event in comparison to the prior art.
- the fuel injector preferably comprises bias means, for example in the form of a helical spring, in the control chamber for biasing the moveable plate into contact with the sealing surface of the control chamber.
- the bias means may advantageously assist with returning the moveable plate into sealing contact with the sealing surface of the control chamber, and assist with retaining the moveable plate in sealing contact with the sealing surface.
- the inlet orifice is located substantially centrally in the moveable plate. This advantageously provides an even force distribution on the plate and prevents the plate from twisting in the control chamber.
- the spill orifice is preferably laterally offset from the inlet orifice.
- the moveable plate may comprise a substantially central recess via which the inlet orifice communicates with the high pressure fuel supply channel when the moveable plate is in contact with the sealing surface of the control chamber.
- the substantially central recess may be defined by a circular inner wall of the moveable plate.
- the inner wall preferably comprises a sealing surface arranged to seal against the sealing surface of the control chamber when the moveable plate is in contact with the sealing surface of the control chamber.
- the size of the central recess may be selected to achieve an appropriate force differential across the moveable plate to retain the plate in sealing contact with the sealing surface of the control chamber during the emptying phase of the control chamber.
- the moveable plate may comprise an annular recess via which the spill orifice communicates with the fuel outlet channel when the moveable plate is in contact with the sealing surface of the control chamber.
- the annular recess and the substantially central recess may be substantially concentric.
- the annular recess may be defined between a circular outer wall of the moveable plate and the circular inner wall of the moveable plate.
- the outer wall preferably comprises a sealing surface arranged to seal against the sealing surface of the control chamber when the moveable plate is in contact with the sealing surface of the control chamber.
- the size of the annular recess may be selected to achieve an appropriate force differential across the plate when the discharge valve is closed to cause the plate to move out of sealing contact with the sealing surface of the control chamber.
- FIG 1 shows a fuel injector 10 according to an embodiment of the present invention.
- the fuel injector 10 comprises an injector valve 12 comprising a valve needle 14 located within an injector nozzle body 16.
- the injector nozzle body 16 is connected to a lower part 18 of an injector housing. Only a lower part 18 of the injector housing and upper parts of the valve needle 14 and injector nozzle body 16 are shown in Figure 1 .
- a lower end (not shown) of the valve needle 14 controls the flow of fuel out of the injector 10 as the valve needle 14 moves up and down in the injector nozzle body 16 between open and closed positions, as described by way of background.
- Movement of the valve needle 14 is controlled by fuel pressure within a control chamber 20.
- the control chamber 20 is defined within the injector nozzle body 16 at an upper end 21 of the valve needle 14.
- the control chamber 20 is supplied with high pressure fuel via a high pressure fuel supply channel 22 defined in the injector housing part 18.
- a fuel outlet channel 24 is also defined in the injector housing part 18 and is arranged to convey fluid which empties from the control chamber 20 to a low pressure reservoir or drain (not shown). Accordingly, the control chamber 20 is filled via the high pressure fuel supply channel 22 and emptied via the fuel outlet channel 24.
- the arrows 23 and 25 in Figure 1 indicate the direction of fuel flow into and out of the control chamber via the high pressure fuel supply channel 22 and the fuel outlet channel 24 respectively.
- filling the control chamber 20 with high pressure fuel causes a downward force to act on the upper end 21 of the valve needle 14. This causes the needle 14 to move downwards in the nozzle body 16 to terminate an injection event. Conversely, emptying the control chamber 20 causes a reduction in pressure in the control chamber 20 resulting in the needle 14 lifting to commence an injection event.
- a discharge valve 26 is provided in the fuel outlet channel 24.
- the discharge valve 26 is operated by a solenoid actuator (not shown).
- the discharge valve 26 is opened to commence an injection event, which causes fuel to exit the control chamber 20 via the fuel outlet channel 24, resulting in the valve needle 14 lifting in the nozzle body 16.
- the discharge valve 26 is closed to terminate an injection event, which causes the control chamber 20 to be re-filled with high pressure fuel, resulting in the lower end (not shown) of the valve needle 14 re-engaging with a valve seat (not shown) at a lower end of the nozzle body 16.
- a moveable plate 28 is provided inside the control chamber 20.
- the moveable plate 28 is substantially circular, and is made from metal.
- the material from which the moveable plate is made may be a high performance steel (such as high speed steel) which has high wear resistance and hardness up to high temperatures (around 500°C).
- the moveable plate 28 comprises a first side 30 and a second side 32.
- the first side 30 is an upper side and the second side 32 is a lower side.
- the first (upper) side 30 faces a sealing surface 34 of the control chamber 20, whilst the second (lower) side 32 faces the upper end 21 of the valve needle 14.
- the sealing surface 34 of the control chamber 20 is provided by a portion of a lower end surface 35 of the injector body 18.
- the sealing surface 34 is highly polished such that it has a mirror finish.
- a helical spring 36 is provided inside the control chamber 20 between the second (lower) side 32 of the plate 28 and the upper end 21 of the valve needle 14.
- the second (lower) side 32 of the moveable plate 28 is substantially flat.
- the spring 36 is arranged to bias the upper side 30 of the moveable plate 28 into sealing contact with the sealing surface 34 of the control chamber 20.
- An inlet orifice 38 and a spill orifice 40 are defined in the moveable plate 28.
- Each orifice 38, 40 extends through the full thickness of the plate 28 between the first and second sides 30, 32 of the plate 28.
- the inlet orifice 38 is located substantially centrally in the plate 28, whilst the spill orifice 40 is laterally offset from the inlet orifice 38.
- the inlet orifice 38 is in fluid communication with the high pressure fuel supply channel 22, and provides a restricted flow path for fuel entering the control chamber 20.
- the spill orifice 40 is in fluid communication with the fuel outlet channel 24, and provides a restricted flow path for fuel exiting the control chamber 20.
- a spill volume 41 is defined in the fuel outlet channel 24 between the discharge valve 26 and the spill orifice 40.
- the inlet orifice 38 communicates with the high pressure fuel supply channel 22 via a substantially central recess 42 defined in the first (upper) side 30 of the moveable plate 28.
- the central recess 42 is substantially circular and defined by a substantially circular inner wall 44 of the moveable plate 28.
- An upper surface 46 of the inner wall 44 defines a sealing surface for sealing against the sealing surface 34 of the control chamber 20.
- the central recess 42 defines a circular surface 48 on the first (upper) side 30 of the moveable plate 28 against which the force of the high pressure fuel in the fuel supply channel 22 acts when the moveable plate 28 is sealed against the sealing surface 34 of the control chamber 20.
- the spill orifice 40 communicates with the fuel outlet channel 24 via an annular recess 50 defined in the first (upper) side 30 of the moveable plate 28.
- the annular recess 50 is defined between the inner wall 44 and a substantially circular outer wall 52 of the moveable plate 28.
- the inner and outer walls 44, 52 are substantially concentric.
- An upper surface 54 of the outer wall 52 defines a sealing surface for sealing against the sealing surface 34 of the control chamber 20.
- the annular recess 50 defines an annular surface 56 on the first (upper) side 30 of the moveable plate 28 against which the force of the high pressure fuel between the spill orifice 40 and discharge valve 26 acts when the moveable plate 28 is sealed against the sealing surface 34 of the control chamber 20 and the discharge valve 26 is closed.
- the moveable plate 28 comprises a generally circular peripheral surface 58, which is provided with flats 60a, 60b and grooves 62a, 62b.
- the peripheral surface 58 of the plate 28 includes a pair of diametrically opposed flat surfaces 60a, 60b, and a pair of diametrically opposed grooves 62a, 62b.
- the flats 60a, 60b and grooves 62a, 62b provide additional fluid flow paths between the peripheral surface 58 of the plate 28 and side wall 64 (see Figure 1 ) of the control chamber 20 for high pressure fluid entering the control chamber 20.
- this shows the fuel injector 10 at rest, i.e. prior to commencing an injection event, or after termination of an injection event.
- the discharge valve 26 is closed, and the control chamber 20 is full of high pressure fuel.
- the spill volume 41 between the discharge valve 26 and the spill orifice 40 is also full of high pressure fuel.
- the forces acting on both sides of the moveable plate 28 due to the pressure of fuel in the control chamber 20 and fuel supply and outlet channels 22, 24 are substantially equal, and the moveable plate 28 is maintained in sealing contact with the sealing surface 34 of the control chamber 20 by the helical spring 36.
- the discharge valve 26 is opened. Referring now to Figure 3 , opening the discharge valve 26 causes a sudden large pressure drop in the spill volume 41 downstream of the spill orifice 40 as the fuel in the spill volume 41 flows past the discharge valve 26 (shown in Figure 1 ) to the low pressure reservoir or drain.
- the control chamber 20 then begins to empty via the spill orifice 40.
- the pressure acting on the upper end 21 of the nozzle needle 14 reduces, and a net upward force acts on the nozzle needle 14 causing the needle 14 to lift inside the nozzle body 16 to commence injection of fuel through the outlets at the lower end of the nozzle body 16 (not shown).
- the moveable plate 28 remains sealed against the sealing surface 34 of the control chamber 20 during this nozzle opening phase, due to the spring biasing force and due to the relative forces acting on the respective first and second sides 30, 32 of the moveable plate 28.
- the fuel pressure in the control chamber 20 acts over a larger area of the second (lower) side 32 of the moveable plate 28 compared to the fuel pressure in the high pressure fuel supply channel 22, which acts against the relatively small circular surface 48 of the central recess 42. Consequently, a net upward force on the moveable plate 28 maintains the plate 28 in sealing contact with the sealing surface 34 of the control chamber 20 during emptying on the control chamber 20.
- the discharge valve 26 (shown in Figure 1 ) is closed. This causes the spill volume 41 between the spill orifice 40 and the discharge valve 26 to fill with high pressure fuel.
- the accumulation of high pressure fuel in the sealed annular recess 50 exerts a downwards force on the annular surface 56 of the moveable plate 28. This initially causes the forces acting on both sides 30, 32 of the moveable plate 28 to equalise, bringing the plate 28 into equilibrium.
- a net downward force acts on the moveable plate 28 causing the plate 28 to move downwardly.
- the high pressure fuel entering the control chamber 20 via the additional flow paths 65 is able to bypass the inlet orifice 38.
- the rate of filling of the control chamber 20, and hence the rate of termination of the injection event is not governed exclusively by the size of the inlet orifice 38. Consequently, the provision of the inlet orifice 38 in the moveable plate 28 allows a much smaller inlet orifice 38 to be used than in the prior art, whilst at the same time achieving a more rapid filling of the control chamber 20 and hence a more rapid termination of an injection event.
- the spill orifice 40 can also be made smaller. This is because the smaller inlet orifice 38 results in a more restricted flow of fuel entering the control chamber 20 during emptying of the control chamber 20 to initiate an injection event (as shown in Figure 3 ) and hence a more restricted spill orifice 40 can be used without compromising the rate at which the control chamber 20 is emptied. Hence a rapid lifting of the nozzle needle 14 is still achieved.
- the moveable plate 28 provided with inlet and outlet orifices 38, 40 therefore allows both the inlet and outlet orifices 38, 40 to be made smaller in comparison to prior art injectors, whilst still achieving rapid initiation of an injection event and even faster termination of the injection event.
- the relatively small inlet and outlet orifices 38, 40 results in a significant reduction of dynamic leakage during emptying of the control chamber 20, as shown in Figure 3 , since the fuel flow path from the high pressure fuel supply channel 22 to the fuel outlet channel 24 via the control chamber 20 is more restricted than in the prior art.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Fuel-Injection Apparatus (AREA)
Description
- The present invention relates to a fuel injector with an improved valve control arrangement for positioning a valve needle of a fuel injector in a position whereby injection of fuel occurs, and in a position whereby injection of fuel is prevented. In particular, the present invention relates to a fuel injector with a valve control arrangement which utilises a moveable plate to control the flow of high pressure fuel between a high pressure fuel supply and an injection valve needle control chamber.
- It is known to control the movement of a valve needle within a fuel injector, to commence and cease fuel injection, by utilising a discharge valve operated by an actuator to control the pressure of fuel within a valve needle control chamber. A valve control arrangement of this type is described in
EP 1 163 440 . In the described arrangement a thrust surface provided at the end of the valve needle that is distal from the valve seat can be subjected to a force resulting from pressurised fuel within the needle control chamber acting against it and a medial thrust surface provided between the distal and proximal ends of the valve needle can be subjected to a force resulting from pressurised fuel within an associated annular chamber in the nozzle body. - Fuel from a high pressure fuel supply source can flow into the valve needle control chamber through an inlet orifice (INO) in the inlet passage. Fuel can flow out from the valve needle control chamber to a low pressure reservoir or drain through an outlet orifice, commonly referred to as a 'spill orifice' (SPO), when the discharge valve is opened by a solenoid actuator. Fuel flows into the annular chamber within the nozzle body from the high pressure fuel supply source and flows out from the chamber through injection orifices which are opened and closed as the valve needle is raised or lowered respectively.
- In operation, to raise the valve needle and hence open the injection orifices, the discharge valve is opened, under the direct control of the solenoid actuator. The fuel within the valve needle control chamber is then able to flow out to the low pressure drain via the SPO. Because the INO is present in the high pressure fuel supply line to the valve needle control chamber the pressure of the fuel within the valve needle control chamber is reduced and thus the downwards force applied to the valve needle, as a result of the fuel acting upon the distal thrust surface, is reduced. High pressure fuel is still acting on the medial thrust surface of the valve needle and the resulting upwards force applied to the valve needle thrust surface is greater than the downwards force applied to the valve needle and thus the valve needle starts to move upwards. When the injection orifices open, the fuel within the chamber in the nozzle body flows out to an engine cylinder, which is at a relatively low pressure, and thus the fuel pressure within the annular chamber in the nozzle body reduces. As the pressure of the fuel within the annular chamber in the nozzle body reduces, the upwards force acting on the valve needle reduces. However, at this point the upwards force acting on the thrust surface is still greater than the downwards force applied to the valve needle and thus the valve needle remains in a raised position and fuel injection through the injection orifices continues.
- In order to lower the valve needle, close the injection orifices and thus cease the injection of fuel, the discharge valve is moved to a closed position. This is achieved by stopping the supply of electrical current to the solenoid and under the direct action of a helical compression spring acting on the discharge valve member. This closes the outlet from the valve needle control chamber to the low pressure drain and thus, since high pressure fuel is still being supplied to the needle control chamber, via the INO, the pressure of fuel within the needle control chamber is raised. The downwards force applied to the valve becomes greater than the upwards force and thus the valve needle moves downwards.
- This prior art valve control arrangement utilises a hydraulically balanced discharge valve. It is necessary to use a hydraulically balanced discharge valve because a small solenoid actuator is used to control movement of the discharge valve and such an actuator is not able to generate sufficient force to close an unbalanced valve against the high pressure of the fuel within the valve needle control chamber acting against it. It is desired to use a small solenoid actuator as this enables the actuator to be placed within the body of the injector. Furthermore, there is a cost reduction associated with the use of a small actuator.
- A disadvantage of hydraulically balanced valves is that they suffer from static leak. This is leak across the discharge valve from the high pressure side, i.e. the valve needle control chamber, to the low pressure drain and is exacerbated by the high pressures and temperatures of the fuel to which the discharge valve is subjected. This static leak requires a higher pump capacity and results in wasted energy as pressurised fuel escapes to the low pressure drain.
- As mentioned above, it is not possible to use an unbalanced valve as the force required to drive it could only be supplied by a larger solenoid actuator, which would not fit within the injector body, or by a different type of actuator, such as a piezo-electric actuator, which would be prohibitively expensive.
- Also, the prior art control arrangement suffers from dynamic fuel leakage when the valve needle is raised. The dynamic leakage occurs between the high pressure fuel inlet and the low pressure reservoir or drain when the discharge valve is open. The dynamic leakage is disadvantageous for the same reasons set forth above in respect to static leakage.
- The inlet orifice and the spill orifice are present in the valve control arrangement of the prior art to enable the greatest closing speed of the valve needle, i.e. the shortest delay between the discharge valve being closed and the pressure of fuel within the valve needle control chamber reaching a level at which the downwards force applied to the valve needle is greater than the force applied upwards, and to enable the greatest opening speed of the valve needle, i.e. the shortest delay between the discharge valve being opened and the pressure of fuel within the valve needle control chamber reducing to a level whereby the upwards force applied to the valve needle is greater than the downwards force applied to the needle.
- In order to have the greatest closing speed for the valve needle it is necessary to fill the valve needle control chamber as quickly as possible. The ideal situation would be to have an unrestricted fuel inlet, i.e. no inlet orifice and a heavily restricted fuel outlet, i.e. a small spill orifice. However, it is also desirable to have a high opening speed for the valve needle and this requires that the valve needle control chamber is emptied as quickly as possible through the outlet passage. In this case it is desirable to have an unrestricted fuel outlet, i.e. no spill orifice and a heavily restricted fuel inlet, i.e. a small inlet orifice.
- There is hence a conflict between the requirements for fast opening and fast closing of the valve needle. A compromise is sought and the inlet orifice and spill orifice are matched to give the best attainable operating characteristics.
- Thus, the prior art control arrangement is limited by suffering from undesirable levels of static and dynamic leakage and from having a relatively long delay time between actuation of the discharge valve and movement of the valve needle.
- There is hence a requirement for a fuel injector which provides a reduction in valve needle movement time with reduced leakage.
-
EP2628939 discloses a fuel injector corresponding to the preamble of claim 1. Another fuel injector is known fromWO 03/071122 A1 US 2010/301143 A1 . - Accordingly, the present invention provides a fuel injector for an internal combustion engine, in particular a compression ignition internal combustion engine, the fuel injector comprising: a fuel injection valve having an injection valve member moveable, in use, under the influence of fuel pressure within a control chamber acting upon it, between a closed position and an open position; a high pressure fuel supply channel to the control chamber; a fuel outlet channel leading from the control chamber to a low pressure reservoir or drain; an actuator operable to open and close a discharge valve located in the fuel outlet channel; a moveable plate located in the control chamber and arranged to move into and out of contact with a sealing surface of the control chamber; a spill orifice provided in the moveable plate and arranged to communicate with the fuel outlet channel when the moveable plate is located in contact with the sealing surface of the control chamber, the spill orifice defining a restricted flow path for fuel to flow out of the control chamber to the fuel outlet channel; and an inlet orifice provided in the moveable plate and arranged to communicate with the high pressure fuel supply channel when the moveable plate is located in contact with the sealing surface of the control chamber, the inlet orifice defining a restricted flow path for fuel to flow from the high pressure fuel supply channel into the control chamber.
- The provision of inlet and spill orifices in the moveable plate enables significantly smaller inlet and outlet orifices to be used in comparison to the prior art. Consequently, the present invention results in a significant reduction of dynamic leakage as low pressure fuel flows out of the control chamber during an emptying phase of the control chamber.
- In use, when the moveable plate is in contact with the sealing surface of the control chamber and the discharge valve is open, fuel flows from the high pressure fuel supply channel into the control chamber through the inlet orifice in the moveable plate, and fuel flows out of the control chamber through the spill orifice in the moveable plate and through the fuel outlet channel to the low pressure reservoir or drain. The provision of the inlet orifice in the moveable plate therefore allows a restricted flow of fuel to enter the control chamber during the emptying phase of the control chamber. The relative sizes of the inlet and spill orifices can advantageously be selected to enable a smooth and controlled lifting of the injection valve member.
- The moveable plate is configured such that one or more additional fluid passages are defined between the control chamber and the high pressure fuel supply channel when the moveable plate is moved out of contact with the sealing surface of the control chamber. The additional fluid passages are defined at least in part by formations such as flats or grooves in a periphery of the moveable plate.
- The additional fluid passages enable fuel from the high pressure fuel supply channel to enter the control chamber bypassing the inlet orifice. Hence the rate of filling of the control chamber is not governed exclusively by the size of the inlet orifice. The inlet orifice can therefore be made smaller without compromising the rate at which the control chamber is filled, and hence the fuel injector can terminate an injection event rapidly despite having a small inlet orifice. Preferably the high pressure fuel supply channel upstream of the additional fluid passage(s) is substantially unrestricted. This allows a substantially unrestricted flow of fuel to enter the control chamber via the additional fluid passages resulting in a very rapid termination of an injection event.
- The injector is configured such that, in use, when the moveable plate moves out of contact with the sealing surface of the control chamber, fuel flows from the high pressure fuel supply channel into the control chamber through the additional fluid passage(s) and through the inlet orifice and spill orifice in the moveable plate. A plurality of flow paths for high pressure fuel entering the control chamber are therefore provided thus allowing faster termination of an injection event in comparison to the prior art.
- The fuel injector preferably comprises bias means, for example in the form of a helical spring, in the control chamber for biasing the moveable plate into contact with the sealing surface of the control chamber. The bias means may advantageously assist with returning the moveable plate into sealing contact with the sealing surface of the control chamber, and assist with retaining the moveable plate in sealing contact with the sealing surface.
- In a preferred embodiment of the invention, the inlet orifice is located substantially centrally in the moveable plate. This advantageously provides an even force distribution on the plate and prevents the plate from twisting in the control chamber. The spill orifice is preferably laterally offset from the inlet orifice.
- The moveable plate may comprise a substantially central recess via which the inlet orifice communicates with the high pressure fuel supply channel when the moveable plate is in contact with the sealing surface of the control chamber. The substantially central recess may be defined by a circular inner wall of the moveable plate. The inner wall preferably comprises a sealing surface arranged to seal against the sealing surface of the control chamber when the moveable plate is in contact with the sealing surface of the control chamber. The size of the central recess may be selected to achieve an appropriate force differential across the moveable plate to retain the plate in sealing contact with the sealing surface of the control chamber during the emptying phase of the control chamber.
- The moveable plate may comprise an annular recess via which the spill orifice communicates with the fuel outlet channel when the moveable plate is in contact with the sealing surface of the control chamber. The annular recess and the substantially central recess may be substantially concentric. The annular recess may be defined between a circular outer wall of the moveable plate and the circular inner wall of the moveable plate. The outer wall preferably comprises a sealing surface arranged to seal against the sealing surface of the control chamber when the moveable plate is in contact with the sealing surface of the control chamber. The size of the annular recess may be selected to achieve an appropriate force differential across the plate when the discharge valve is closed to cause the plate to move out of sealing contact with the sealing surface of the control chamber.
- In order that the present invention may be more readily understood, an example of the invention will now be described in detail with reference to the accompanying figures, in which:
-
Figure 1 is a partial schematic view of a fuel injector according to an embodiment of the invention, in which a moveable plate defining an inlet orifice and a spill orifice is located inside a control chamber; -
Figure 2 is a schematic plan view of the moveable plate shown inFigure 1 ; -
Figure 3 is a partial schematic view of the fuel injector ofFigure 1 , in which the moveable plate is shown in contact with a sealing surface of the control chamber; and -
Figure 4 is a partial schematic view of the fuel injector ofFigure 1 , in which the moveable plate is moved out of contact with the sealing surface of the control chamber. -
Figure 1 shows afuel injector 10 according to an embodiment of the present invention. Thefuel injector 10 comprises aninjector valve 12 comprising avalve needle 14 located within aninjector nozzle body 16. Theinjector nozzle body 16 is connected to alower part 18 of an injector housing. Only alower part 18 of the injector housing and upper parts of thevalve needle 14 andinjector nozzle body 16 are shown inFigure 1 . A lower end (not shown) of thevalve needle 14 controls the flow of fuel out of theinjector 10 as thevalve needle 14 moves up and down in theinjector nozzle body 16 between open and closed positions, as described by way of background. - Movement of the
valve needle 14 is controlled by fuel pressure within acontrol chamber 20. Thecontrol chamber 20 is defined within theinjector nozzle body 16 at anupper end 21 of thevalve needle 14. Thecontrol chamber 20 is supplied with high pressure fuel via a high pressurefuel supply channel 22 defined in theinjector housing part 18. Afuel outlet channel 24 is also defined in theinjector housing part 18 and is arranged to convey fluid which empties from thecontrol chamber 20 to a low pressure reservoir or drain (not shown). Accordingly, thecontrol chamber 20 is filled via the high pressurefuel supply channel 22 and emptied via thefuel outlet channel 24. Thearrows Figure 1 indicate the direction of fuel flow into and out of the control chamber via the high pressurefuel supply channel 22 and thefuel outlet channel 24 respectively. - In general, and as described by way of background, filling the
control chamber 20 with high pressure fuel causes a downward force to act on theupper end 21 of thevalve needle 14. This causes theneedle 14 to move downwards in thenozzle body 16 to terminate an injection event. Conversely, emptying thecontrol chamber 20 causes a reduction in pressure in thecontrol chamber 20 resulting in theneedle 14 lifting to commence an injection event. - A
discharge valve 26 is provided in thefuel outlet channel 24. Thedischarge valve 26 is operated by a solenoid actuator (not shown). Thedischarge valve 26 is opened to commence an injection event, which causes fuel to exit thecontrol chamber 20 via thefuel outlet channel 24, resulting in thevalve needle 14 lifting in thenozzle body 16. Conversely, thedischarge valve 26 is closed to terminate an injection event, which causes thecontrol chamber 20 to be re-filled with high pressure fuel, resulting in the lower end (not shown) of thevalve needle 14 re-engaging with a valve seat (not shown) at a lower end of thenozzle body 16. - A
moveable plate 28 is provided inside thecontrol chamber 20. Referring also toFigure 2 , themoveable plate 28 is substantially circular, and is made from metal. The material from which the moveable plate is made may be a high performance steel (such as high speed steel) which has high wear resistance and hardness up to high temperatures (around 500°C). Themoveable plate 28 comprises afirst side 30 and asecond side 32. In the orientation of theinjector 10 shown inFigure 1 , thefirst side 30 is an upper side and thesecond side 32 is a lower side. The first (upper)side 30 faces a sealingsurface 34 of thecontrol chamber 20, whilst the second (lower)side 32 faces theupper end 21 of thevalve needle 14. The sealingsurface 34 of thecontrol chamber 20 is provided by a portion of alower end surface 35 of theinjector body 18. The sealingsurface 34 is highly polished such that it has a mirror finish. - A
helical spring 36 is provided inside thecontrol chamber 20 between the second (lower)side 32 of theplate 28 and theupper end 21 of thevalve needle 14. The second (lower)side 32 of themoveable plate 28 is substantially flat. Thespring 36 is arranged to bias theupper side 30 of themoveable plate 28 into sealing contact with the sealingsurface 34 of thecontrol chamber 20. - An
inlet orifice 38 and aspill orifice 40 are defined in themoveable plate 28. Eachorifice plate 28 between the first andsecond sides plate 28. Theinlet orifice 38 is located substantially centrally in theplate 28, whilst thespill orifice 40 is laterally offset from theinlet orifice 38. When themoveable plate 28 is in contact with the sealingsurface 34 of the control chamber 20 (as shown inFigure 1 ), theinlet orifice 38 is in fluid communication with the high pressurefuel supply channel 22, and provides a restricted flow path for fuel entering thecontrol chamber 20. Similarly, with themoveable plate 28 in contact with the sealingsurface 34 of thecontrol chamber 20, thespill orifice 40 is in fluid communication with thefuel outlet channel 24, and provides a restricted flow path for fuel exiting thecontrol chamber 20. Aspill volume 41 is defined in thefuel outlet channel 24 between thedischarge valve 26 and thespill orifice 40. - The
inlet orifice 38 communicates with the high pressurefuel supply channel 22 via a substantiallycentral recess 42 defined in the first (upper)side 30 of themoveable plate 28. Thecentral recess 42 is substantially circular and defined by a substantially circularinner wall 44 of themoveable plate 28. Anupper surface 46 of theinner wall 44 defines a sealing surface for sealing against the sealingsurface 34 of thecontrol chamber 20. Thecentral recess 42 defines acircular surface 48 on the first (upper)side 30 of themoveable plate 28 against which the force of the high pressure fuel in thefuel supply channel 22 acts when themoveable plate 28 is sealed against the sealingsurface 34 of thecontrol chamber 20. - The
spill orifice 40 communicates with thefuel outlet channel 24 via anannular recess 50 defined in the first (upper)side 30 of themoveable plate 28. Theannular recess 50 is defined between theinner wall 44 and a substantially circularouter wall 52 of themoveable plate 28. The inner andouter walls upper surface 54 of theouter wall 52 defines a sealing surface for sealing against the sealingsurface 34 of thecontrol chamber 20. Theannular recess 50 defines anannular surface 56 on the first (upper)side 30 of themoveable plate 28 against which the force of the high pressure fuel between thespill orifice 40 anddischarge valve 26 acts when themoveable plate 28 is sealed against the sealingsurface 34 of thecontrol chamber 20 and thedischarge valve 26 is closed. - As shown in
Figure 2 , themoveable plate 28 comprises a generally circularperipheral surface 58, which is provided withflats grooves peripheral surface 58 of theplate 28 includes a pair of diametrically opposedflat surfaces opposed grooves moveable plate 28 is moved out of sealing contact with the sealingsurface 34 of thecontrol chamber 20, theflats grooves peripheral surface 58 of theplate 28 and side wall 64 (seeFigure 1 ) of thecontrol chamber 20 for high pressure fluid entering thecontrol chamber 20. - The operation of the
fuel injector 10 will now be described. - Referring still to
Figure 1 , this shows thefuel injector 10 at rest, i.e. prior to commencing an injection event, or after termination of an injection event. Thedischarge valve 26 is closed, and thecontrol chamber 20 is full of high pressure fuel. Thespill volume 41 between thedischarge valve 26 and thespill orifice 40 is also full of high pressure fuel. The forces acting on both sides of themoveable plate 28 due to the pressure of fuel in thecontrol chamber 20 and fuel supply andoutlet channels moveable plate 28 is maintained in sealing contact with the sealingsurface 34 of thecontrol chamber 20 by thehelical spring 36. - In order to initiate an injection event, the
discharge valve 26 is opened. Referring now toFigure 3 , opening thedischarge valve 26 causes a sudden large pressure drop in thespill volume 41 downstream of thespill orifice 40 as the fuel in thespill volume 41 flows past the discharge valve 26 (shown inFigure 1 ) to the low pressure reservoir or drain. Thecontrol chamber 20 then begins to empty via thespill orifice 40. As thecontrol chamber 20 empties, the pressure acting on theupper end 21 of thenozzle needle 14 reduces, and a net upward force acts on thenozzle needle 14 causing theneedle 14 to lift inside thenozzle body 16 to commence injection of fuel through the outlets at the lower end of the nozzle body 16 (not shown). - At the same time as the
control chamber 20 empties via thespill orifice 40, a restricted supply of high pressure fuel is continually supplied to thecontrol chamber 20 through theinlet orifice 38, as indicated by thearrow 66 inFigure 3 . The relative sizes of the inlet and spillorifices valve needle 14 and to minimise dynamic leakage of fuel. - The
moveable plate 28 remains sealed against the sealingsurface 34 of thecontrol chamber 20 during this nozzle opening phase, due to the spring biasing force and due to the relative forces acting on the respective first andsecond sides moveable plate 28. In particular, the fuel pressure in thecontrol chamber 20 acts over a larger area of the second (lower)side 32 of themoveable plate 28 compared to the fuel pressure in the high pressurefuel supply channel 22, which acts against the relatively smallcircular surface 48 of thecentral recess 42. Consequently, a net upward force on themoveable plate 28 maintains theplate 28 in sealing contact with the sealingsurface 34 of thecontrol chamber 20 during emptying on thecontrol chamber 20. - In order to terminate the injection event, the discharge valve 26 (shown in
Figure 1 ) is closed. This causes thespill volume 41 between thespill orifice 40 and thedischarge valve 26 to fill with high pressure fuel. The accumulation of high pressure fuel in the sealedannular recess 50 exerts a downwards force on theannular surface 56 of themoveable plate 28. This initially causes the forces acting on bothsides moveable plate 28 to equalise, bringing theplate 28 into equilibrium. As fuel pressure increases in theannular recess 50, a net downward force acts on themoveable plate 28 causing theplate 28 to move downwardly. - Referring now to
Figure 4 , when theplate 28 moves downwardly, it moves out of sealing contact with the sealingsurface 34 of thecontrol chamber 20. Fuel from the high pressurefuel supply channel 22 then rapidly flows into the region of thecontrol chamber 20 above themoveable plate 28. Theflats grooves moveable plate 28, discussed above with reference toFigure 2 , then provideadditional flow paths 65 around theperiphery 58 of theplate 28 between the high pressurefuel supply channel 22 and thecontrol chamber 20 below theplate 28. As shown by thearrows 68 inFigure 4 , fuel from the high pressurefuel supply channel 22 rapidly flows into thecontrol chamber 20 via theadditional flow paths 65 and via both the inlet and spillorifices flow paths 65 results in very rapid filling of thecontrol chamber 20 and hence a rapid descent of thevalve needle 14 to terminate the injection event. - The high pressure fuel entering the
control chamber 20 via theadditional flow paths 65 is able to bypass theinlet orifice 38. Hence the rate of filling of thecontrol chamber 20, and hence the rate of termination of the injection event, is not governed exclusively by the size of theinlet orifice 38. Consequently, the provision of theinlet orifice 38 in themoveable plate 28 allows a muchsmaller inlet orifice 38 to be used than in the prior art, whilst at the same time achieving a more rapid filling of thecontrol chamber 20 and hence a more rapid termination of an injection event. - As the
inlet orifice 38 is able to be made smaller with the present arrangement, thespill orifice 40 can also be made smaller. This is because thesmaller inlet orifice 38 results in a more restricted flow of fuel entering thecontrol chamber 20 during emptying of thecontrol chamber 20 to initiate an injection event (as shown inFigure 3 ) and hence a morerestricted spill orifice 40 can be used without compromising the rate at which thecontrol chamber 20 is emptied. Hence a rapid lifting of thenozzle needle 14 is still achieved. - The
moveable plate 28 provided with inlet andoutlet orifices outlet orifices outlet orifices control chamber 20, as shown inFigure 3 , since the fuel flow path from the high pressurefuel supply channel 22 to thefuel outlet channel 24 via thecontrol chamber 20 is more restricted than in the prior art. - The provision of the
inlet orifice 38 in themovable plate 28 results in a permanent flow path from the high pressurefuel supply channel 22 to thecontrol chamber 20. Consequently, when thefuel injector 10 is in the rest state, with themoveable plate 28 in sealing contact with the sealingsurface 34 of thecontrol chamber 20, as shown inFigure 1 , small amounts of high pressure fuel are able to enter and exit thecontrol chamber 20 through theinlet orifice 38 andspill orifice 40 respectively to compensate for any static leakage of fuel that may occur across thedischarge valve 26. Theinjector 10 therefore does not suffer from any pressure loss in thecontrol chamber 20 due to static leakage.
Claims (13)
- A fuel injector (10) for a compression ignition internal combustion engine, the fuel injector comprising:a fuel injection valve having an injection valve member (14) moveable, in use, under the influence of fuel pressure within a control chamber (20) acting upon it, between a closed position and an open position;a high pressure fuel supply channel (22) to the control chamber (20);a fuel outlet channel (24) leading from the control chamber (20) to a low pressure reservoir or drain;an actuator operable to open and close a discharge valve (26) located in the fuel outlet channel (24);a moveable plate (28) located in the control chamber (20) and arranged to move into and out of contact with a sealing surface (34) of the control chamber (20);a spill orifice (40) provided in the moveable plate (28) and arranged to communicate with the fuel outlet channel (24) when the moveable plate (28) is located in contact with the sealing surface (34) of the control chamber (20), the spill orifice (40) defining a restricted flow path for fuel to flow out of the control chamber (20) to the fuel outlet channel (24); andan inlet orifice (38) provided in the moveable plate (28) and arranged to communicate with the high pressure fuel supply channel (22) when the moveable plate (28) is located in contact with the sealing surface (34) of the control chamber (20), the inlet orifice (38) defining a restricted flow path for fuel to flow from the high pressure fuel supply channel (22) into the control chamber (20)characterised in that the moveable plate (28) is configured such that one or more additional fluid passages (60a, 60b, 62a, 62b), defined at least in part by formations such as flats or grooves (60a, 60b, 62a, 62b) in a periphery of the moveable plate (28), are between the control chamber (20) and the high pressure fuel supply channel (22) to permit fuel flow therethrough when the moveable plate (28) is moved out of contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of Claim 1, wherein, in use when the moveable plate (28) is in contact with the sealing surface (34) of the control chamber (20) and the discharge valve (26) is open, fuel flows from the high pressure fuel supply channel (22) into the control chamber (20) through the inlet orifice (38), and fuel flows out of the control chamber (20) through the spill orifice (40) and through the fuel outlet channel to the low pressure reservoir or drain.
- The fuel injector of Claim 1, wherein, in use when the moveable plate (28) moves out of contact with the sealing surface (34) of the control chamber (20), fuel flows from the high pressure fuel supply channel (22) into the control chamber (20) through the additional fluid passage(s) and through the inlet orifice (38) and spill orifice (40) in the moveable plate (28).
- The fuel injector of Claim 3, wherein the high pressure fuel supply channel (22) upstream of the additional fluid passage(s) is substantially unrestricted.
- The fuel injector of any preceding claim, further comprising bias means (36) provided in the control chamber (20) for biasing the moveable plate (28) into contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of any preceding claim, wherein the inlet orifice (38) is located substantially centrally in the moveable plate (28).
- The fuel injector of Claim 6, wherein the spill orifice (40) is laterally offset from the inlet orifice (38).
- The fuel injector of any preceding claim, wherein the moveable plate (28) comprises a substantially central recess (42) via which the inlet orifice (38) communicates with the high pressure fuel supply channel (22) when the moveable plate (28) is in contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of Claim 8, wherein the substantially central recess (42) is defined by an inner wall (44) of the moveable plate (28), and wherein the inner wall comprises a sealing surface arranged to seal against the sealing surface of the control chamber when the moveable plate is in contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of any preceding claim, wherein the moveable plate (28) comprises an annular recess (50) via which the spill orifice (40) communicates with the fuel outlet channel (24) when the moveable plate is in contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of Claim 10 when dependent on Claim 9, wherein the annular recess (50) is defined between an outer wall (52) of the moveable plate (28) and the inner wall (44) of the moveable plate (28), and wherein the outer wall (52) comprises a sealing surface arranged to seal against the sealing surface (34) of the control chamber (20) when the moveable plate (28) is in contact with the sealing surface (34) of the control chamber (20).
- The fuel injector of Claim 10 or Claim 11 when dependent upon Claim 8 or Claim 9, wherein the annular recess (50) and the substantially central recess (42) are substantially concentric.
- The fuel injector of any preceding claim, wherein the actuator is a solenoid actuator.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB1517148.1A GB201517148D0 (en) | 2015-09-29 | 2015-09-29 | Fuel injector |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3150839A1 EP3150839A1 (en) | 2017-04-05 |
EP3150839B1 true EP3150839B1 (en) | 2018-05-23 |
Family
ID=54544237
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP16190307.5A Not-in-force EP3150839B1 (en) | 2015-09-29 | 2016-09-23 | Fuel injector |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP3150839B1 (en) |
GB (1) | GB201517148D0 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102017116367A1 (en) * | 2017-07-20 | 2019-01-24 | Liebherr-Components Deggendorf Gmbh | Device for controlling an injector |
GB2587015B (en) * | 2019-09-13 | 2021-12-08 | Delphi Tech Ip Ltd | Fuel injector |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU2003201421A1 (en) * | 2002-02-22 | 2003-09-09 | Crt Common Rail Technologies Ag | Fuel injection valve for internal combustion engines |
JP5493966B2 (en) * | 2009-06-02 | 2014-05-14 | 株式会社デンソー | Fuel injection device |
DE102012202546A1 (en) * | 2012-02-20 | 2013-08-22 | Robert Bosch Gmbh | Fuel injector |
DE102012204837A1 (en) * | 2012-03-27 | 2013-10-02 | Continental Automotive Gmbh | Injector component for fuel injection valve that is utilized for injection of fuel into diesel combustion engine in motor car, has nozzle needle whose front wall is coupled with two spring elements in operating mode |
-
2015
- 2015-09-29 GB GBGB1517148.1A patent/GB201517148D0/en not_active Ceased
-
2016
- 2016-09-23 EP EP16190307.5A patent/EP3150839B1/en not_active Not-in-force
Also Published As
Publication number | Publication date |
---|---|
EP3150839A1 (en) | 2017-04-05 |
GB201517148D0 (en) | 2015-11-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2093410B1 (en) | A fuel injector with an improved valve control arrangement | |
EP1851427B1 (en) | Common rail injector with active needle closing device | |
US10941744B2 (en) | Fuel injector | |
US5219122A (en) | Fuel injection system for engine | |
EP3150839B1 (en) | Fuel injector | |
JP2017519938A (en) | Fuel injector for internal combustion engine | |
US7874502B2 (en) | Control valve arrangement | |
WO2006038636A1 (en) | Fuel injection device | |
US6273066B1 (en) | Fuel injection for an internal combustion engine | |
KR102244948B1 (en) | Fuel injection nozzle | |
JP2008280958A (en) | Fuel injection valve | |
JPH02209678A (en) | Solenoid valve | |
EP3464874B1 (en) | Fuel injection valve unit for an internal combustion piston engine and a method of operating the fuel injection valve unit | |
JP5059030B2 (en) | Improved control valve device | |
JP2005320904A (en) | Fuel injection valve | |
JP2016528431A (en) | Injection device | |
CZ20021919A3 (en) | Liquid control valve | |
JPS6234998B2 (en) | ||
JPS61187572A (en) | High-pressure fuel injector for internal combustion engine | |
CN110700952A (en) | Method for controlling the injection rate of a gaseous fuel and fuel injector | |
JP4055330B2 (en) | Fuel injection device | |
JP2006046221A (en) | Fuel injection valve | |
JP2005320897A (en) | Fuel injection valve | |
JP2004278357A (en) | Injector | |
JPS59218358A (en) | Fuel injection nozzle device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
17P | Request for examination filed |
Effective date: 20171005 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
INTG | Intention to grant announced |
Effective date: 20171206 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1001723 Country of ref document: AT Kind code of ref document: T Effective date: 20180615 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602016003200 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 3 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180823 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180823 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20180927 Year of fee payment: 3 Ref country code: FR Payment date: 20180925 Year of fee payment: 3 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180824 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1001723 Country of ref document: AT Kind code of ref document: T Effective date: 20180523 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602016003200 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
26N | No opposition filed |
Effective date: 20190226 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20180930 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 602016003200 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20180523 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180523 Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20160923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190930 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190930 Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200401 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20180923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190930 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20200923 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200923 |