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
  • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
• • 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
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
  • F01L9/21—Valve-gear or valve arrangements actuated non-mechanically by electric means actuated by solenoids
  • F01L2009/2115—Moving coil actuators
• • 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
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
  • F01L9/21—Valve-gear or valve arrangements actuated non-mechanically by electric means actuated by solenoids
  • F01L2009/2157—Actuator cooling means

Definitions

• the invention relates to the control of the valves in an internal combustion engine. It relates, more specifically, an electromagnetic valve actuator in such an engine.
• valves The control of the valves must satisfy the following constraints. First, the movement of the valves must be fast and precise, to facilitate the admission, respectively the evacuation, of the gases. Then, the valve stroke must be sufficient to ensure a high flow of gas, whether admission or evacuation. Finally, the forces transmitted to the valves must be important (especially evacuation), to overcome the pressure in the combustion chamber.
• valves in the internal combustion engines are performed mechanically by a distribution system comprising one or more camshaft (s) which drive the valves, either directly or indirectly via rockers.
• a camshaft is rotatably coupled to the crankshaft by a timing belt or chain.
• An alternative valve control technique is electromagnetic actuation.
• each valve is driven by means of an electromagnetic actuator.
• One or more magnets generate an electromagnetic field suitable for to move, by the force of Laplace, a support on which is wound a coil traversed by an electric current and of which the valve is secured.
• an armature defining at least two superimposed magnetic circuits, namely an upper magnetic circuit and a lower magnetic circuit, each magnetic circuit including a magnet, a ferromagnetic annular outer pole piece, in contact with the magnet, and a ferromagnetic central core, the polar piece and the core defining between them a gap;
• a mobile equipment including:
• An objective is to propose an electromagnetic actuator that responds to all the constraints associated with the control of the valves: good speed, good control, sufficient stroke of the valves, importance of the transmitted forces, and which is adaptable to engines of high power.
• an electromagnetic actuator for an internal combustion engine valve which comprises:
• an armature defining a magnetic circuit including:
• a ferromagnetic primary core housed in the primary bore and defining with the pole piece a primary air gap
• a primary mobile equipment including:
• the pole piece defines a secondary bore adjacent to the primary bore
• the magnetic circuit includes a ferromagnetic secondary core housed in the secondary bore and defining with the pole piece a secondary air gap;
• the actuator comprises a secondary mobile unit including: a secondary carcass provided with a tubular body immersed in the secondary air gap;
• This actuator is thus adapted to a motor having four valves per cylinder while ensuring essential functions such as:
• the primary coil and the secondary coil comprise a common supply circuit
• the primary coil and the secondary coil each comprise a separate power supply circuit
• the frame comprises a cover for securing the primary core and the secondary core with the pole piece;
• the cover comprises two fingers each engaged with the primary core or the secondary core, the two fingers being separated from one another by a distance;
• the spacing of the fingers of the cover is slightly less than a center distance measured between the primary bore and the secondary bore;
• the primary coil and the secondary coil respectively consist of an upper primary coil and a lower primary coil and an upper secondary coil and a lower secondary coil;
• the electromagnetic actuator comprises an upper pole piece and a lower pole piece.
• an internal combustion engine comprising an electromagnetic actuator as presented above and, thirdly, a motor vehicle comprising a motor as presented above.
• FIG. 1 is a perspective view from above of a motor vehicle with an internal combustion engine having at least one electromagnetic valve actuator;
• Figure 2 is a schematic sectional view of a cylinder of the engine of Figure 1;
• FIG. 3 is a sectional view of the electromagnetic actuator according to a first embodiment
• Figure 4 is an exploded perspective view from above of the electromagnetic actuator
• Figure 5 is a sectional view of the electromagnetic actuator according to a second embodiment
• Figure 6 is a sectional view along the axis CC of Figure 5.
• a vehicle 1 automobile here a particular vehicle, but it could be any other type of vehicle: utility, truck, construction equipment.
• the vehicle 1 is equipped with an internal combustion engine 2 provided with cylinders 3 defining combustion chambers 4 and in which are slidably mounted pistons 5 connected, by connecting rods 6, to a crankshaft 7 whose rotation causes the wheels 8 of the vehicle 1 via a transmission (not shown).
• an internal combustion engine 2 provided with cylinders 3 defining combustion chambers 4 and in which are slidably mounted pistons 5 connected, by connecting rods 6, to a crankshaft 7 whose rotation causes the wheels 8 of the vehicle 1 via a transmission (not shown).
• the engine 2 comprises, for each cylinder 3 four valves 9 distributed in pairs, namely two intake valves 9a and two valves 9b exhaust.
• valves 9 without particular reference to their use for admission or exhaust.
• Each valve 9 comprises a rod 10 which extends along a central axis X which defines an axial direction. At one end of the rod 10 is formed a head 11. Each valve 9 is movable in translation relative to a cylinder head 12 of the engine 2 between a closed position in which the head 11 of the valve 9 bears against a seat 13 for closing an intake duct 14 (or, respectively, an exhaust duct 15) and an open position in which the head 11 is spaced from the seat 13 to put the cylinder 3 in communication with the intake duct 14 (or, respectively, the exhaust duct).
• the engine 2 is of the diesel direct injection type and comprises, for this purpose, an injector 16 which opens directly into the combustion chamber 4, but it could be any other type of internal combustion engine: gasoline, indirect injection, hybrid.
• Each valve 9 is controlled in position by an electromagnetic actuator 17.
• This actuator 17 is itself controlled by a computerized control unit 18 equipped with a programmable processor.
• the actuator 17 is shown in section in Figures 3 and 5 respectively according to a first and a second embodiment and an exploded view in Figure 4, according to the first embodiment.
• the actuator 17 comprises a frame 19 and two crews 20, 21 mobiles namely a primary mobile and a secondary mobile 21 crew.
• the frame 19 comprises:
• a substantially cylindrical ferromagnetic primary core 24 defining, with the pole pieces 23a, 23b, a primary air gap;
• a substantially cylindrical ferromagnetic secondary core 26 defining, with the pole pieces 23a, 23b, a secondary gap 27, and
• the armature 19 comprises a primary bore 29 and a secondary bore 30, adjacent to the primary bore 29, in which the primary core 24 and the secondary core 26, the primary and secondary bores 29, respectively, are received. Secondary being made jointly in the pieces 23a, 23b polar and the magnet 22.
• the lid 28 is provided with a plate 31 and two fingers 32 adapted to be housed each in one of the cores 24, 26 primary and secondary. According to the embodiment shown in the figures, and as can be seen in FIG. 6, the two fingers 32 are spaced from each other by a distance C1 which is slightly smaller than a center distance P1 between the primary bore 29 and the secondary bore which causes reduction of the primary and secondary air gaps 25, 27 in a central region of the electromagnetic actuator.
• the primary mobile unit 20 comprises a primary housing 33, an upper primary coil 34, a lower primary coil 35 and a valve 9.
• the primary carcass 33 comprises a tubular body 36 open at an upper end 37 and provided with an upper annular groove 38 and a lower annular groove 39 in which are respectively housed the upper primary coil 34 and the lower primary coil.
• the primary carcass 33 comprises at a lower end, a bottom 40 on which the valve 9 is screwed by means of screws 41.
• the valve 9 is welded to the bottom 40 of the carcass 33.
• the secondary mobile unit 21 comprises a secondary carcass 42, an upper secondary coil 43, a lower secondary coil 44 and a valve 9.
• the secondary casing 42 comprises a tubular body 45 open at an upper end 46 and provided with an upper annular groove 47 and a lower annular groove 48 in which are respectively housed the upper primary coil 43 and the primary coil 44 lower.
• the secondary carcass 42 comprises at a lower end, a bottom 49 on which the valve 9 is screwed by means of screws 41.
• the coils 34, primary 35 upper and lower and the coils 43, 44 upper and lower secondary consist of a wire of circular section.
• the coils may consist of a wire of rectangular section.
• the electromagnetic actuator 17 is assembled in the manner described below.
• the armature 19 is first assembled by bonding the magnet 22 on the upper part 23a and the lower part 23b.
• the cover 28 is also bonded to the primary core 24 and the secondary core 26 by its fingers 32 each engaging with one of the cores 24, 26.
• the primary core 24 and the secondary core 26 are inserted respectively in the primary bore 29 and in the secondary bore 30 and held in position by means of a flange (not shown) holding the cover 28 with one of the parts 23a, 23b polar.
• the fixing means chosen for the assembly of the frame 19 is the bonding which then allows to to overcome the problems of disturbances of the magnetic field especially generated when the assembly is achieved by means of screws.
• the upper primary coil 34 is inserted into the upper annular groove 38 of the primary carcass 33, the lower primary coil 35 is inserted into the lower annular groove 39 of the carcass. 33 and the valve 9 is assembled on the bottom 40 of the primary carcass 33 by means of the screws 41.
• the upper secondary coil 43 is inserted into the upper annular groove 47 of the second secondary carcass 42
• the lower secondary coil 44 is inserted into the lower annular groove 48 lower of the secondary carcass 42
• the valve 9 is assembled on the bottom 49 of the secondary carcass 42 by means of the screws 41.
• the valve 9 is welded to the bottom 49 of the carcass 42.
• the electromagnetic actuator 17 is finally assembled by the insertion of the primary mobile unit 20 and the secondary mobile unit 21 respectively into the primary bore 29 and the secondary bore 30.
• an electric current is transmitted to the coils 34, 35, 43, 44 in order to interact with a magnetic field generated by the magnet 22 (shown in phantom in the figures) for translating the crews 20 , 21 movable in the bores 29, 30 of the frame 19.
• the coils 34, 35 and 43, 44 are constructed so that the same current flows in an opposite direction depending on whether it borrows the coil 34, 43 upper or the coil 35, 44 lower than one same crew 20, 21 mobile.
• the mobile crews 20, 21 are controlled independently of one another.
• the secondary mobile crew 21 may remain closed while the primary mobile crew is open.
• Adjusting the intensity of the current transmitted to the coils 34, 35, 43, 44 makes it possible to vary the speed of opening and closing of the valves 9 but also to vary the spacing of the valves 9 relative to the armature 19 and thus to adjust the flow rate of fluid flowing from the intake pipe 14 to the combustion chamber 4 or the combustion chamber 4 to the exhaust pipe 15.
• FIGS. 5 and 6 A variant of the electromagnetic actuator 17 is shown in FIGS. 5 and 6.
• This variant implements a cooling means of the electromagnetic actuator 17. Indeed, the use of high electric currents to generate the forces required for the movement of the valves 9, generates, under certain conditions of use of the electromagnetic actuator 17, an excess of heat and, thus, a heating of the actuator Which, combined with the heat generated by the operation of the engine 2 itself, can prematurely degrade the electromagnetic actuator 17.
• the magnet 22 is provided with two cooling ducts 50 each opening into the primary bore 29 or into the secondary bore 30.
• the carcasses 33, 42 primary and secondary are then provided with a substantially central annular belt 51, which, when the electromagnetic actuator 17 is assembled, is at the right of a cooling duct 50 so that a cooling fluid, injected into the frame 19, does not encounter any obstacle as soon as it enters the primary and secondary bores 29, 30.
• the belt 51 has a height such that in the high position, in the low position or in an intermediate position between the high position and the low position of the moving crews 20, 21, the cooling ducts 50 are facing this position. belt 51.
• the difference between the centers C1 and P1 also increases the distance between the primary and secondary cores 24, 26 and the cooling ducts 50 opening into the primary and secondary bores 29, 30 and so on. facilitate the introduction of the cooling fluid into the air gaps 25, 27 primary and secondary.
• the cooling fluid is injected from a compressor by pipes 52 which are housed in the cooling ducts 50.
• This cooling fluid is represented in FIGS. 5 and 6 by dashed lines.
• the electromagnetic actuator 17 is then cooled by direct contact of the fluid with the upper and lower primary coils 34, 35 and the upper and lower secondary coils 43, 44.
• the hot fluid having stored a portion of the heat of the coils 34, 35, 43, 44, is removed from the electromagnetic actuator 17 at its upper and lower ends and then recovered in a motor circuit (not shown).
• the fluid is air
• the hot air could be recovered to be injected into the engine 2, after a possible cooling and a possible compression.
• another fluid that the air could be used as for example, water or oil which have a thermal capacity and a higher heat transfer coefficient than air.
• the cooling ducts 50 are made in the parts 23a, 23b polar or jointly in the parts 23a, 23b polar and in the magnet 22.
• the cooling ducts 50 are each made on a different face of the electromagnetic actuator 17.
• cooling ducts 50 are adjacent and are formed on the same face of the electromagnetic actuator 17.
• the electromagnetic actuator 17 that has just been presented has many advantages.
• the electromagnetic actuator 17 has the advantage of reducing the size of the engine 2. Indeed, a motor 2 provided with these electromagnetic actuators 17 does not use a camshaft, which reduces the space requirement. of the engine 2, especially in height. The gain in space reduces the height of the engine compartment of a vehicle 1 and thus allows a more aerodynamic form of the vehicle 1, which becomes less fuel-consuming and has a more attractive silhouette.
• the actuators 17 are adaptable to the engines 2 having four valves 9 per cylinder 3. In fact, the compactness of the actuators 17 allows the control of two adjacent valves 9 for the admission or exhaust of a cylinder 3 of the engine 2.
• the electromagnetic actuator 17 allows precise control of the valves 9.
• Each valve 9 of the same electromagnetic actuator 17 can be controlled independently of the other.
• each primary coil 34, 35 and secondary 43, 44 is powered by a dedicated electrical circuit.
• a single electrical circuit can be used. The accuracy of the control is provided by the regulation of the intensity of the current transmitted to the coils 34, 35, 43, 44 primary and secondary and then ensures a rapid opening and closing of the valves 9.
• the electromagnetic actuator 17 makes it possible to generate a magnetic field large enough to counter the pressure prevailing in the combustion chamber 4 and to allow the valves 9 to open.
• an electromagnetic actuator 17 as described can be used. both intake and exhaust cylinders 3 instead of camshafts.
• the cooling of the electromagnetic actuator 17 ensures a better service life of the actuator 17, by regulating its operating temperature, and allows the use of the electromagnetic actuator 17 on motors 2 which can achieve high operating speeds, torque and peak power.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=52102845

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (3)

• 2014
  • 2014-10-03 FR FR1459464A patent/FR3026779B1/fr not_active Expired - Fee Related
• 2015
  • 2015-09-14 EP EP15788455.2A patent/EP3201441B1/de active Active
  • 2015-09-14 WO PCT/FR2015/052441 patent/WO2016051041A1/fr active Application Filing

Also Published As

Similar Documents

Legal Events