WO2018019457A1 - Appareil pour commander les soupapes d'un moteur à combustion interne - Google Patents

Appareil pour commander les soupapes d'un moteur à combustion interne Download PDF

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Publication number
WO2018019457A1
WO2018019457A1 PCT/EP2017/064032 EP2017064032W WO2018019457A1 WO 2018019457 A1 WO2018019457 A1 WO 2018019457A1 EP 2017064032 W EP2017064032 W EP 2017064032W WO 2018019457 A1 WO2018019457 A1 WO 2018019457A1
Authority
WO
WIPO (PCT)
Prior art keywords
actuation surface
piston
actuation
mode
inlet
Prior art date
Application number
PCT/EP2017/064032
Other languages
English (en)
Inventor
Thomas Johnson
Samuel Jenkinson
Original Assignee
Jaguar Land Rover Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jaguar Land Rover Limited filed Critical Jaguar Land Rover Limited
Priority to DE112017003763.8T priority Critical patent/DE112017003763B4/de
Publication of WO2018019457A1 publication Critical patent/WO2018019457A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
    • F01L1/267—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder with means for varying the timing or the lift of the valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • F01L9/11—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • F01L9/11—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column
    • F01L9/12—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column with a liquid chamber between a piston actuated by a cam and a piston acting on a valve stem
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • F01L9/11—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column
    • F01L9/12—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column with a liquid chamber between a piston actuated by a cam and a piston acting on a valve stem
    • F01L9/14—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column with a liquid chamber between a piston actuated by a cam and a piston acting on a valve stem the volume of the chamber being variable, e.g. for varying the lift or the timing of a valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/0253—Fully variable control of valve lift and timing using camless actuation systems such as hydraulic, pneumatic or electromagnetic actuators, e.g. solenoid valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0005—Deactivating valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L2800/00—Methods of operation using a variable valve timing mechanism
    • F01L2800/06—Timing or lift different for valves of same cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces

Definitions

  • the present disclosure relates to apparatus for controlling valves of an internal combustion engine.
  • apparatus for controlling movement of inlet poppet valves of at least one combustion chamber of an internal combustion engine In particular, but not exclusively it relates to apparatus for controlling movement of inlet poppet valves of at least one combustion chamber of an internal combustion engine.
  • aspects of the invention relate to an apparatus, an internal combustion engine, and a vehicle.
  • an inlet poppet valve is lifted away from a valve seat and into a combustion chamber, to open an inlet port and allow the intake of air into the combustion chamber through the inlet port.
  • the inlet poppet valve is returned to the valve seat to close the inlet port.
  • apparatus e.g. a camshaft and valve train.
  • the valve train may comprise a hydraulic control system actuated by the camshaft. The displacement of fluid within the hydraulic control system during actuation by the camshaft moves a small piston within a cylinder. The piston pushes a valve stem of an inlet poppet valve to lift the inlet poppet valve.
  • a combustion chamber may comprise a plurality of inlet ports, each inlet port opened and closed by an inlet poppet valve.
  • an apparatus for controlling lifting of inlet poppet valves of at least one combustion chamber of an internal combustion engine comprising: a first piston arranged to be actuated to control a lift of a first inlet poppet valve of a combustion chamber, comprising a first actuation surface and a second different actuation surface; a second piston arranged to be actuated to control a lift of a second inlet poppet valve of the combustion chamber, comprising a third actuation surface; and a hydraulic control system arranged to operate in: a first mode which causes simultaneous actuation of the first actuation surface and the second actuation surface but not the third actuation surface; and a second mode which causes simultaneous actuation of the first actuation surface and the third actuation surface, but not the second actuation surface.
  • This provides the advantage of compensating for the tendency of hydraulic control systems to lift the first inlet poppet valve further in the first mode compared to the second mode. In some examples this allows greater control of intake air velocity.
  • the second actuation surface and the third actuation surface may have identical areas. This provides the advantage of eliminating the tendency of hydraulic control systems to lift the first inlet poppet valve further in the first mode compared to the second mode.
  • the first actuation surface, the second actuation surface and the third actuation surface may have identical areas. This provides the advantage of eliminating the tendency of hydraulic control systems to lift the first inlet poppet valve further in the first mode than the second inlet poppet valve is capable of lifting.
  • the apparatus may be arranged to provide a first restoring force resisting actuation of the first piston and a second restoring force resisting actuation of the second piston, wherein the ratio of a parameter controlling the magnitude of the first restoring force to the area of the first actuation surface combined with/or of the second actuation surface is the same as the ratio of a parameter controlling the magnitude of the second restoring force to the area of the third actuation surface.
  • the first actuation surface and the second actuation surface may be arranged such that the direction of actuating force acting on the first piston via the first actuation surface and the second actuation surface in the first mode is the same as the direction of actuating force acting on the first piston via the first actuation surface in the second mode.
  • This provides the advantage of reducing wear of the apparatus as the first piston is actuated axially and without side loading.
  • At least a portion of the first piston may be T-shaped in cross-section and may comprise the first actuation surface and the second actuation surface. This provides the advantage of reducing wear of the apparatus as the first piston is capable of being actuated using symmetrical distribution of force, avoiding side loading.
  • the first actuation surface and the second actuation surface may be rotationally symmetrical about a common central axis.
  • the first actuation surface and the second actuation surface may be non-coplanar.
  • the first piston may define a seal between the first actuation surface and the second actuation surface including while the first piston is actuated. This provides the advantage that hydraulic fluid does not easily move between the first actuation surface and the second actuation surface while the first piston is actuated, ensuring reliable operation of the apparatus in the first mode.
  • the hydraulic control system may comprise switching means for switching between the first mode and the second mode.
  • the apparatus may be arranged to contain relatively high pressure fluid from a first fluid source for applying actuating force to the first piston and to the second piston, and relatively low pressure fluid from a second different fluid source.
  • the apparatus can utilize the low pressure fluid source for avoiding hydrostatic lock.
  • the apparatus may comprise a seat for the first piston, the seat and the first piston defining a variable volume cavity therebetween, and may comprise a vent positioned to enable the relatively low pressure fluid to at least enter the variable volume cavity during actuation of the first piston.
  • vent prevents hydrostatic locking by fluid trapped in the variable volume cavity. Trapped fluid would resist actuation of the first piston, for example by resisting changes in the volume of the internal volume cavity.
  • the seat and the second actuation surface of the first piston may define the variable volume cavity therebetween, and the apparatus may comprise vent switching means for switching whether the variable volume cavity is exposed to the relatively low pressure fluid or to the relatively high pressure fluid during actuation of the first piston.
  • vent prevents fluid trapped in the variable volume cavity from resisting actuation of the first piston in the second mode, for example by preventing fluid compression or expansion in the variable volume cavity.
  • the vent switching means provides the advantage of an apparatus with fewer components, as the vent can perform two functions, enabling passage of the relatively high pressure fluid and the relatively low pressure fluid.
  • the vent switching means may be operable such that in the first mode the variable volume cavity is exposed to the relatively high pressure fluid and in the second mode the variable volume cavity is exposed to the relatively low pressure fluid. This provides the advantage of conserving relatively high pressure fluid by enabling it to be pushed out of the variable volume cavity in the first mode while remaining in the hydraulic control system for later use.
  • the apparatus may comprise a fluid routing switch comprising: a first inlet for the relatively high pressure fluid; a second separate inlet for the relatively low pressure fluid; a first outlet for the second actuation surface; and a second separate outlet for the third actuation surface, wherein the fluid routing switch may be arranged such that: in the first mode the first inlet is exposed to the first outlet but not the second outlet and the second inlet is not exposed to the first outlet or the second outlet; and in the second mode the first inlet is exposed to the second outlet but not the first outlet, and the second inlet is exposed to the first outlet but not the second outlet.
  • the relatively low pressure fluid may comprise liquid phase fluid.
  • an internal combustion engine comprising the apparatus as described herein.
  • a vehicle comprising the apparatus or the internal combustion engine as described herein.
  • an apparatus comprising: first means for controlling a lift of a first valve of a combustion chamber, comprising a first actuation surface and a second different actuation surface; second means for controlling a lift of a second valve of the combustion chamber, comprising a third actuation surface; and control means arranged to operate in: a first mode which causes simultaneous actuation of the first actuation surface and the second actuation surface but not the third actuation surface; and a second mode which causes simultaneous actuation of the first actuation surface and the third actuation surface, but not the second actuation surface.
  • the first means is a first piston.
  • the second means is a second piston.
  • the control means is a hydraulic control system.
  • Fig 1 illustrates an example of a vehicle 1 ;
  • Fig 2A illustrates an example of an apparatus 6 actuating a single inlet poppet valve 3
  • Fig 2B illustrates an example of an apparatus 6 actuating two inlet poppet valves 3, 4;
  • Fig 3A illustrates another example of an apparatus 6 actuating a single inlet poppet valve 3;
  • Fig 3B illustrates another example of an apparatus 6 actuating two inlet poppet values 3, 4.
  • the figures illustrate an apparatus 6 for controlling lifting of inlet poppet valves of at least one combustion chamber 5 of an internal combustion engine 2, the apparatus 6 comprising: a first piston 8 arranged to be actuated to control a lift of a first inlet poppet valve 3 of a combustion chamber 5, comprising a first actuation surface 9 and a second different actuation surface 1 1 ; a second piston 13 arranged to be actuated to control a lift of a second inlet poppet valve 4 of the combustion chamber 5, comprising a third actuation surface 14; and a hydraulic control system 7 arranged to operate in: a first mode which causes simultaneous actuation of the first actuation surface 9 and the second actuation surface 1 1 but not the third actuation surface 14; and a second mode which causes simultaneous actuation of the first actuation surface 9 and the third actuation surface 14, but not the second actuation surface 1 1 .
  • Fig 1 illustrates a vehicle 1 .
  • the vehicle 1 is a land based vehicle, in this example a passenger car. Embodiments of the invention could be incorporated within a vehicle such as the vehicle 1 of Fig 1 .
  • Figs 2A and 2B schematically illustrate an example of the apparatus 6 in use.
  • Fig 2A shows the apparatus 6 in a first mode of operation and
  • Fig 2B shows the apparatus 6 in a second mode of operation.
  • Figs 2A and 2B illustrate the apparatus 6 and a combustion chamber 5 of an internal combustion engine 2.
  • the internal combustion engine 2 comprises a plurality of combustion chambers 5.
  • the apparatus 6 comprises a first piston 8, a second piston 13, and a hydraulic control system 7.
  • the apparatus 6 comprises a first inlet poppet valve 3 and a second inlet poppet valve 4.
  • first inlet poppet valve 3 and second inlet poppet valve 4 are separate components from the apparatus 6 and can be supplied separately from the apparatus 6.
  • the apparatus 6 is proximal to the combustion chamber 5 of the internal combustion engine 2, such that in use the first inlet poppet valve 3 is positioned between the first piston 8 and the combustion chamber 5 and the second inlet poppet valve 4 is positioned between the second piston 13 and the combustion chamber 5.
  • the first inlet poppet valve 3 is arranged to be moved by actuation of the first piston 8 and the second inlet poppet valve 4 is arranged to be moved by actuation of the second piston 13.
  • the first piston 8 and second piston 13 are movable when actuated.
  • the hydraulic control system 7 comprises a hydraulic circuit providing a first source of hydraulic fluid and is arranged to displace hydraulic fluid in use.
  • the hydraulic control system 7 is arranged such that displacement of the hydraulic fluid within the hydraulic circuit causes actuation of at least the first piston 8; and the second piston 13.
  • the first piston 8 comprises a first actuation surface 9 and a second actuation surface 1 1 .
  • the second piston 13 comprises a third actuation surface 14.
  • An actuation surface such as the first actuation surface 9, second actuation surface 1 1 and third actuation surface 14, is defined by a surface area on a piston such as the first piston 8 or the second piston 13.
  • the surface area may extend over at least an entire face of the piston.
  • the surface area can be arranged such that displacement of hydraulic fluid adjacent to the surface area in a direction at least partially orthogonal to the plane of the surface area imparts a distributed load over the surface area.
  • the surface area is arranged to cause actuation of the piston when an actuating force acts over the surface area.
  • the actuating force is an unbalanced force on the piston caused at least in part by the distributed load, which causes the piston to move in the direction of displacement of the hydraulic fluid.
  • the first actuation surface 9 extends over a first surface area of the first piston 8.
  • a first arrow 10 is shown which extends from the hydraulic control system 7 to the first actuation surface 9.
  • the first arrow 10 is not part of the apparatus 6, and is merely illustrative of a direction in which displaced hydraulic fluid is directed.
  • the first arrow 10 points towards the first actuation surface 9, therefore displaced hydraulic fluid is directed towards the first actuation surface 9, actuating the first actuation surface 9.
  • the second actuation surface 1 1 extends over a second surface area of the first piston 8.
  • the second surface area does not overlap the first surface area.
  • the first actuation surface 9 and the second actuation surface 1 1 are separated from each other by a discontinuity.
  • the discontinuity is not capable of being acted upon by an actuating force caused by displacement of hydraulic fluid.
  • a second arrow 12 is shown which extends from the hydraulic control system 7 to the second actuation surface 1 1 .
  • the second arrow 12 is not part of the apparatus 6, and is merely illustrative of a direction in which displaced hydraulic fluid is directed.
  • the second arrow 12 points towards the second actuation surface 1 1 , therefore displaced hydraulic fluid is directed towards the second actuation surface 1 1 , actuating the second actuation surface 1 1 .
  • the total actuating force which moves the first piston 8 is the sum of the actuating force acting on the first actuation surface 9 and the actuating force acting on the second actuation surface 1 1 .
  • the resulting movement of the first piston 8 pushes the first inlet poppet valve 3, moving the first inlet poppet valve 3 away from its valve seat by a lift distance L. Movement of a poppet valve away from its valve seat is referred to herein as lifting of the poppet valve.
  • the third actuation surface 14 extends over a surface area of the second piston 13.
  • the third actuation surface is for causing the second piston 13 to be moved by actuating force acting on the third actuation surface 14.
  • movement of the second piston 13 pushes the second inlet poppet valve 4 out of its valve seat, allowing air to enter the combustion chamber 5.
  • Fig 2A illustrates the apparatus 6 in the first mode of operation.
  • the first mode of operation is a single valve lift mode which causes simultaneous actuation of the first actuation surface 9 and the second actuation surface 1 1 but not the third actuation surface 14, causing only the first inlet poppet valve 3 to lift.
  • Fig 2B illustrates the apparatus 6 of Fig 2A and corresponding reference numerals refer to corresponding features.
  • Fig 2B shows the apparatus 6 in the second mode of operation.
  • Fig 2B The difference between Fig 2B and Fig 2A is that the second arrow 12 is omitted and instead a third arrow 15 is shown extending from the hydraulic control system 7 towards the third actuation surface 14 of the second piston 13.
  • the third arrow 15 extends from the hydraulic control system 7 to the third actuation surface 14.
  • the third arrow 15 is not part of the apparatus 6, and is merely illustrative of a direction in which displaced hydraulic fluid is directed.
  • the third arrow 15 points towards the third actuation surface 14, therefore displaced hydraulic fluid is directed towards the third actuation surface 14, actuating the third actuation surface 14.
  • the hydraulic control system 7 causes actuation of the first actuation surface 9 and the third actuation surface 14 but not the second actuation surface 1 1 .
  • the hydraulic fluid moves the first piston 8 and the second piston 13. This results in lifting of both the first inlet poppet valve 3 and the second inlet poppet valve 4 simultaneously.
  • the second actuation surface 1 1 receives zero actuating force, or at least insufficient force to itself cause movement of the first piston 8.
  • Fig 2B illustrates the apparatus 6 in the second mode of operation.
  • the second mode is a dual valve lift mode as shown in Fig 2B which causes simultaneous actuation of the first actuation surface 9 and the third actuation surface 14, but not the second actuation surface 1 1 , causing both inlet poppet valves 3, 4 to lift.
  • the apparatus 6 compensates for the tendency of the hydraulic control system 7 to lift the first inlet poppet valve 3 further in the single valve lift mode compared to the dual valve lift mode.
  • the apparatus 6 can be further adapted to eliminate this tendency by suitable control of surface areas of the actuation surfaces. Examples are described below.
  • the surface area of the second actuation surface 1 1 is identical to the surface area of the third actuation surface 14.
  • the first inlet poppet valve 3 will lift by distance L in both the single valve lift mode and the dual valve lift mode.
  • the first actuation surface 9, the second actuation surface 1 1 and the third actuation surface 14 have identical surface areas.
  • the first inlet poppet valve 3 will lift by distance L in both the single valve lift mode and the dual valve lift mode and the second inlet poppet valve 4 will lift by the distance L in the dual valve lift mode.
  • Figs 3A and 3B schematically illustrate another example of an apparatus 6 comprising all of the features of the apparatus 6 described in relation to Figs. 2A and 2B, as well as several other new features which are described herein. Corresponding reference numerals refer to corresponding features.
  • Fig 3A shows the apparatus 6 in the first mode of operation corresponding to the single valve lift mode and Fig 3B shows the apparatus 6 in the second mode of operation corresponding to the dual valve lift mode.
  • the hydraulic control system 7 comprises a master piston 36 within a cylinder 34.
  • At least a portion of the surface of the master piston 36 forms part of an exterior surface of the apparatus 6 and is not exposed to the internal hydraulic fluid within the apparatus 6, and at least a different opposing portion of the surface of the master piston 36 is exposed to the internal hydraulic fluid within the apparatus 6.
  • the master piston 36 is arranged to be actuated by a camshaft lobe 35. More specifically, the camshaft lobe 35 moves the master piston 36 within the cylinder 34. The movement of the master piston 36 by the camshaft lobe 35 displaces the hydraulic fluid within the apparatus 6.
  • the hydraulic control system 7 comprises a hydraulic accumulator 30 and a blocking switch 32.
  • the blocking switch 32 When the blocking switch 32 is closed, to block flow therethrough, the hydraulic accumulator 30 is not exposed to displaced hydraulic fluid.
  • the blocking switch 32 When the blocking switch 32 is open, to enable flow therethrough, the hydraulic accumulator 30 is exposed to displaced hydraulic fluid.
  • the blocking switch 32 may be moved between open and closed positions using any suitable means such as a solenoid.
  • the blocking switch 32 is open, the displaced hydraulic fluid fills the hydraulic accumulator 30 without imparting sufficient actuating force to lift the first inlet poppet valve 3 or the second inlet poppet valve 4. In the example of Fig 3A the blocking switch 32 is blocked.
  • the hydraulic control system 7 comprises a first passage 38 for displaced hydraulic fluid extending from the cylinder 34 towards the first piston 8 and the second piston 13.
  • the first passage 38 leads to the first actuation surface 9.
  • hydraulic fluid displaced by the master piston imparts actuating force on the first actuation surface 9 as denoted by arrow 10.
  • the hydraulic control system 7 comprises a second passage 40 meeting the first passage 38 at a junction, and extending to switching means 41 , 42 in the form of a fluid routing switch 41 having a first inlet 42 for fluid from the second passage 40.
  • the fluid routing switch 41 is a type of directional control valve for routing the displaced hydraulic fluid.
  • the second passage 40 extends from the junction to a first inlet 42 of the fluid routing switch 41 .
  • the hydraulic control system 7 comprises a third passage 50 extending from a first outlet 46 of the fluid routing switch 41 to the second actuation surface 1 1 of the first piston 8.
  • the fluid routing switch 41 is arranged such that the first inlet 42 of the fluid routing switch 41 is exposed to the first outlet 46 of the fluid routing switch 41 . Therefore hydraulic fluid displaced by the master piston passes through the third passage 50 to actuate the second actuation surface 1 1 , as denoted by arrow 12.
  • the hydraulic control system 7 comprises a fourth passage 52 extending from a second outlet 48 of the fluid routing switch 41 to the third actuation surface 14 of the second piston 13.
  • the first inlet 42 of the fluid routing switch 41 is not exposed to the second outlet 48 of the fluid routing switch 41 . Therefore hydraulic fluid displaced by the master piston does not cause the second piston 13 to move. Therefore the hydraulic control system 7 of Fig 3A is operating in the single valve lift mode, in which only the first inlet poppet valve 3 lifts by distance L.
  • the fluid routing switch 41 of Fig 3A also comprises a second separate inlet 44. The second separate inlet is exposed to separate fluid from a separate fluid source 66.
  • the separate fluid is liquid phase fluid.
  • the separate fluid is engine oil and the separate fluid source 66 is an engine oil gallery.
  • the fluid routing switch 41 of Fig 3A is movable between two positions to control whether the second actuation surface 1 1 or the third actuation surface 14 is caused to be actuated in dependence on application of fluid displacement. In other examples the fluid routing switch 41 is movable between more than two positions.
  • any suitable actuator can be used for controlling the position of the fluid routing switch 41 , such as a solenoid, or a fluid actuator as shown in Fig 3A.
  • the fluid routing switch 41 is a two-inlet, two-outlet switch. In other examples any suitable number of inlets and outlets can be provided.
  • the fluid actuator of Fig 3A comprises a source 68 of pressurized fluid, a switch 56, and a fifth passage 54.
  • the switch 56 can control the direction in which fluid travels through the fifth passage 54, thereby controlling operation of the fluid routing switch 41 .
  • the switch 56 could be operated using any suitable actuator controlled by any suitable controller such as an engine control unit.
  • a first piston 8 and second piston 13 is included as described in relation to Figs 2A and 2B.
  • the shape of the first piston 8 differs from the shape of the second piston 13.
  • the first piston 8 is T-shaped in cross-section whereas the second piston 13 is a cylinder and may be a uniform cylinder.
  • the T-shaped first piston 8 is inverted.
  • the T-shaped cross-section is symmetrical about an axis of symmetry.
  • the axis of symmetry passes through the centroid of the T-shaped cross-section.
  • the first actuation surface 9 and the second actuation surface 1 1 are rotationally symmetrical about a common central axis and the common central axis is co-axial with the axis of symmetry.
  • the maximum diameter of the second actuation surface 1 1 is a predetermined multiple of the maximum diameter of the first actuation surface 9. The multiple is, for example, equal to the square root of two.
  • the T-shaped first piston 8 is formed of a continuous piece of material and has a flange and a leg.
  • the flange extends perpendicularly to the leg while the leg extends parallel to the axis of symmetry.
  • the flange and leg are also rotationally symmetrical about the axis of symmetry.
  • the flange defines opposing planar continuous surfaces, a first of which defines the second actuation surface 1 1 and a second of which comprises the portion in contact with the first inlet poppet valve 3.
  • the second actuation surface 1 1 forms an annular ring, the centre of the ring defining the base of the leg.
  • the first actuation surface 9 is defined by an end surface of the leg, and is therefore non- coplanar with the second actuation surface 1 1 .
  • a sidewall of the leg extending between the base of the leg and the end of the leg defines the discontinuity between the first actuation surface 9 and the second actuation surface 1 1 .
  • Zero side loading means that the direction of total actuating force acting on the first piston 8 in the single valve lift mode is the same as the direction of total actuating force acting on the first piston 8 in the dual valve lift mode.
  • the function of zero side loading is to prevent wear caused by unbalanced lateral forces on the first piston 8 orthogonal to the direction in which the first piston 8 is constrained to move.
  • Suitable shapes for the first piston 8 include shapes having at least one axis of symmetry and shapes which are rotationally symmetrical about at least one plane.
  • the first piston 8 of Fig 3A is arranged proximal to a seat 58.
  • the seat 58 defines a T-shaped cavity having a leg cavity for the leg of the first piston 8 and a flange cavity for the flange of the first piston 8.
  • the cavity provides a close fit to resist hydraulic fluid leakage between the first actuation surface 9 and the second actuation surface 1 1 .
  • first piston 8 is biased against the seat 58 while the first piston 8 is not actuated, for example via a first restoring force 62 such as a return spring force.
  • At least a portion of the leg of the first piston 8 protrudes into the leg cavity of the seat 58 even while the first piston 8 is actuated fully to lift the first inlet poppet valve 3 to distance L. Therefore the sidewall of the leg acts as a continual seal 16 between the first actuation surface 9 and the second actuation surface 1 1 .
  • the sidewall of the leg can support a sealing o-ring, for providing additional sealing.
  • a variable volume cavity 60 is defined between the second actuation surface 1 1 of the first piston 8 and the flange cavity of the seat 58 such that when the first piston 8 is lifted away from the seat 58 the internal volume of the variable volume cavity 60 increases.
  • hydraulic fluid is displaced into the variable volume cavity via an aperture 18 in the seat 58 for the third passage 50.
  • the first restoring force 62 moves the first piston 8 back towards the seat 58, causing the first piston 8 to push hydraulic fluid out of the internal volume within the seat 58 and back towards the first passage 38.
  • the hydraulic fluid in the variable volume cavity 60 is pushed out of the variable volume cavity 60 and into the third passage 50, via the aperture 18.
  • first piston 8 is provided with a first restoring force 62 and the second piston 13 is provided with a second restoring force 64.
  • each piston may be provided with a return spring for moving the pistons into their respective seats when actuation ceases.
  • first restoring force 62 and second restoring force 64 can be provided by other mechanical, hydraulic, electrical or pneumatic means.
  • the restoring forces 62, 64 can resist actuation of the respective pistons 8, 13 but are not sufficiently high to prevent any actuation of the respective pistons 8, 13.
  • a parameter of the first restoring force 62 and the second restoring force 64 differs, for example if the respective return springs have different spring constants, then the surface areas of the respective actuation surfaces 9, 1 1 , 14 need not all be identical to provide the advantages described herein.
  • the ratio of spring constant for the first restoring force 62 to the surface area of the first actuation surface 9 and/or of the second actuation surface 1 1 is the same as the ratio of spring constant for the second restoring force 64 to the surface area of the third actuation surface 14.
  • suitable parameters may include any constant of proportionality between displacement and restoring force, such as magnetic reluctance of a magnetic material.
  • Fig 3B illustrates the apparatus 6 of Fig 3A in which the hydraulic control system 7 is in the second mode of operation corresponding to the dual valve lift mode.
  • Corresponding reference numerals refer to corresponding features.
  • the blocking switch 32 to the hydraulic accumulator 30 remains closed. Therefore the apparatus 6 as shown in Fig 3B is lifting the first inlet poppet valve 3 by distance L and the second inlet poppet valve 4 by distance L, in a similar manner to the apparatus 6 of Fig 2B.
  • Fig 3B the apparatus 6 has switched from the single valve lift mode to the dual valve lift mode by switching the fluid routing switch 41 to a different position in which the first inlet 42 is exposed to the second outlet 48 but not the first outlet 46.
  • Switching is achieved by repositioning the fluid routing switch 41 between the positions of Fig 3A and Fig 3B, using the fluid actuator for example.
  • displaced hydraulic fluid from passage 38 actuates the first actuation surface 9, as shown by arrow 10.
  • the first piston 8 is able to draw the relatively low pressure fluid from the separate fluid source 66 into the variable volume cavity 60 via the second inlet 44, first outlet 46, third passage 50 and aperture 18, while the first piston 8 is actuated by the relatively high pressure fluid acting on the first actuation surface 9.
  • the pressure of the relatively low pressure fluid from the separate fluid source 66 is relatively lower than the pressure of the hydraulic fluid in the hydraulic control system 7, to ensure that the relatively low pressure fluid does not actuate the second actuation surface 1 1 .
  • the first piston 8 is then able to draw the relatively low pressure fluid into the variable volume cavity 60 while the first piston 8 is actuated and lifted away from its seat 58, and to vent the relatively low pressure fluid in the variable volume cavity 60 back into the separate fluid source 66 via the aperture 18, third passage 50, first outlet 46 and second inlet 44, when the first piston 8 is no longer actuated and is returning to its seat 58. Consequently hydrostatic locking does not occur in the variable volume cavity 60.
  • the fluid routing switch 41 described above serves two simultaneous functions: switching means 41 , 42 for switching between the single valve lift mode and the dual valve lift mode; and vent switching means 41 , 44 for switching whether the variable volume cavity 60 is exposed to the relatively low pressure fluid or to the relatively high pressure fluid during actuation of the first piston 8. In other examples these functions are provided by separate components.
  • the hydraulic control system 7 as described in relation to Figs. 3A and 3B is arranged to operate in: a single valve lift mode as shown in Fig 3A which causes simultaneous actuation of the first actuation surface 9 and the second actuation surface 1 1 but not the third actuation surface 14; and a dual valve lift mode as shown in Fig 3B which causes simultaneous actuation of the first actuation surface 9 and the third actuation surface 14, but not the second actuation surface 1 1 .
  • the apparatus 6 is arranged to switch between the single valve lift mode and the dual valve lift mode only while the master piston is not being moved, for instance by the camshaft lobe 35. This has the benefit of predictable valve lifting behavior and avoiding mixing of the hydraulic fluid and the separate fluid from the separate fluid source 66.
  • the apparatus 6 is scalable for use with any number of combustion chambers by repeating the structure shown in Figs 2A to 3B.
  • the apparatus 6 is scalable for use with any number of inlet poppet valves per combustion chamber.
  • the second mode may be an all valve lift mode in which all inlet poppet valves of a combustion chamber are lifted.
  • each of the first inlet poppet valve 3 and second inlet poppet valve 4 is actuated by a different hydraulic circuit, enabling the opening time and/or closing time of the first inlet poppet valve 3 to be different from the opening time or the closing time of the second inlet poppet valve 4.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

L'invention porte sur un appareil (6) pour commander le levage de soupapes à champignon d'entrée d'au moins une chambre de combustion d'un moteur à combustion interne. L'appareil comprend: un premier piston (8) conçu pour être actionné pour commander la levée d'une première soupape à champignon d'entrée (3) d'une chambre de combustion (5), comprenant une première surface d'actionnement (9) et une seconde surface d'actionnement différente (11); un second piston (13) conçu pour être actionné pour commander la levée d'une seconde soupape à champignon d'entrée (4) de la chambre de combustion (5), comprenant une troisième surface d'actionnement (14); et un système de commande hydraulique (7) conçu pour fonctionner dans: un premier mode qui provoque l'actionnement simultané de la première surface d'actionnement (9) et de la deuxième surface d'actionnement (11); et un deuxième mode qui provoque l'actionnement simultané de la première surface d'actionnement (9) et de la troisième surface d'actionnement (14).
PCT/EP2017/064032 2016-07-26 2017-06-08 Appareil pour commander les soupapes d'un moteur à combustion interne WO2018019457A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE112017003763.8T DE112017003763B4 (de) 2016-07-26 2017-06-08 Vorrichtung zum steuern von ventilen eines verbrennungsmotors

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1612884.5 2016-07-26
GB1612884.5A GB2552499B (en) 2016-07-26 2016-07-26 Apparatus for controlling valves using a hydraulic control system

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WO2018019457A1 true WO2018019457A1 (fr) 2018-02-01

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DE (1) DE112017003763B4 (fr)
GB (1) GB2552499B (fr)
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022228725A1 (fr) * 2021-04-29 2022-11-03 Caterpillar Energy Solutions Gmbh Unité d'actionnement de soupape d'échappement pour moteur à soupapes multiples

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4202542A1 (de) * 1991-02-12 1992-08-13 Volkswagen Ag Variabler ventiltrieb fuer ein hubventil
EP0767295A1 (fr) * 1995-10-03 1997-04-09 New Sulzer Diesel Ag Commande de soupape hydraulique
EP2693007A1 (fr) * 2012-07-31 2014-02-05 C.R.F. Società Consortile per Azioni Moteur à combustion interne présentant un système pour l'actionnement variable des soupapes d'admission pourvues de soupapes à solénoïde à trois voies et procédé pour commander ce moteur

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6899068B2 (en) 2002-09-30 2005-05-31 Caterpillar Inc Hydraulic valve actuation system
EP1674673B1 (fr) * 2004-12-23 2007-03-21 C.R.F. Società Consortile per Azioni Moteur à combustion interne avec soupapes hydrauliques variables
WO2015175213A1 (fr) 2014-05-12 2015-11-19 Borgwarner Inc. Actionnement de soupape entrainée par vilebrequin

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4202542A1 (de) * 1991-02-12 1992-08-13 Volkswagen Ag Variabler ventiltrieb fuer ein hubventil
EP0767295A1 (fr) * 1995-10-03 1997-04-09 New Sulzer Diesel Ag Commande de soupape hydraulique
EP2693007A1 (fr) * 2012-07-31 2014-02-05 C.R.F. Società Consortile per Azioni Moteur à combustion interne présentant un système pour l'actionnement variable des soupapes d'admission pourvues de soupapes à solénoïde à trois voies et procédé pour commander ce moteur

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022228725A1 (fr) * 2021-04-29 2022-11-03 Caterpillar Energy Solutions Gmbh Unité d'actionnement de soupape d'échappement pour moteur à soupapes multiples

Also Published As

Publication number Publication date
GB2552499B (en) 2019-11-27
GB201612884D0 (en) 2016-09-07
GB2552499A (en) 2018-01-31
DE112017003763B4 (de) 2024-10-31
DE112017003763T5 (de) 2019-04-11

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