Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/20—Output circuits, e.g. for controlling currents in command coils
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/13—Electromagnets; Actuators including electromagnets with armatures characterised by pulling-force characteristics
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/16—Rectilinearly-movable armatures
  • H01F7/1638—Armatures not entering the winding
  • H01F7/1646—Armatures or stationary parts of magnetic circuit having permanent magnet
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/20—Output circuits, e.g. for controlling currents in command coils
  • F02D2041/2068—Output circuits, e.g. for controlling currents in command coils characterised by the circuit design or special circuit elements
  • F02D2041/2079—Output circuits, e.g. for controlling currents in command coils characterised by the circuit design or special circuit elements the circuit having several coils acting on the same anchor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/16—Rectilinearly-movable armatures
  • H01F2007/1692—Electromagnets or actuators with two coils
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/121—Guiding or setting position of armatures, e.g. retaining armatures in their end position
  • H01F7/122—Guiding or setting position of armatures, e.g. retaining armatures in their end position by permanent magnets
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/14—Pivoting armatures

Definitions

• the present invention relates to the field of polarized electromagnetic actuators, more particularly intended for applications requiring short travel times over a significant travel, and, for example, the electrical actuation of the valves of an internal combustion engine.
• polarized electromagnetic actuators for actuation are known, as described, for example, in US Pat. No. 5,078,235.
• An actuator according to this example comprises two fixed electromagnets disposed on either side of a movable ferromagnetic armature capable of coming into contact with one or the other of the electromagnets according to the supply of two coils each mounted on one of the stators. electromagnets.
• Return springs are also distributed on either side of the electromagnetic system ensuring a position of balance without current in the middle of the total travel of the mobile armature.
• these solutions have several defects. For example, they require a holding current when the actuator is in the extreme position (for example, a closed valve). In addition, they require an initialization phase during startup of the system, intended to move the mobile mass from a central position to the high position and offer limited controllability possibilities.
• electrical actuators of polarized valves to overcome these defects, and to provide specific advantages to polarized bistable actuators: holding in end position without power consumption, better controllability of the system ...
• An actuator according to this example comprises two fixed electromagnets, at least one of which is polarized by a pair of magnets judiciously placed, arranged on either side of a movable ferromagnetic member which can come into contact with the first electromagnet or the second according to the selected control sequences.
• the present example makes it possible to electrically modulate the currentless attraction forces generated by the magnets through the electromagnets on the movable member but also to reduce the power consumption by stable positions without current.
• each of the magnets interacts only with an electromagnet, which induces a non-optimal use of the magnetic flux generated by the magnets. It is the same for coils that do not offer optimal cooperative use with the two polarized electromagnets.
• the object of the present invention is to optimize the efficiency of the magnets implanted in the polarized electromagnetic structure and to propose an optimized and simplified control mode.
• the actuator according to the invention has a single fixed stator part judiciously polarized by at least one magnet and associated with at least one coil, and a movable ferromagnetic part composed of two ferromagnetic armatures integral with the same mobile element and arranged on either side of the stator.
• the electromagnetic actuator comprises a first stable position without current when the so-called "upper” armature of the mobile part is in contact with the upper part of the stator thereby defining a first remarkable magnetic circuit associated with a first preferential flux path.
• the electromagnetic actuator comprises a second stable position without current when the "lower" armature of the movable part is in contact with the lower part of the stator thus defining a second remarkable magnetic circuit associated with a second path of preferential flow.
• the magnet cooperates fully (near leaks) with the moving part at the end of the stroke.
• the same magnet cooperates alternately with one or the other of the ferromagnetic parts at the end of the stroke.
• the magnet cooperates "totally" with the moving part at the end of the stroke, then "totally” with the other moving part.
• this type of structure has the particularity of producing a very large power without current in each of the stable positions without current at the end of the race.
• this type of actuator has the particularity of having a relatively small force over a large part of its travel, as shown in FIGS. 1 & 2.
• the counter-electromotive force exerted on the mobile part in motion is greatly reduced over most of the race.
• the fixed part is formed by a ferromagnetic core surrounded by a transversely magnetized thin magnet, said core being further surrounded by at least one coaxial electrical coil with the magnet permanent, said fixed part further comprising an outer yoke surrounding said permanent magnet and said fixed coil to form polar horns adapted to cooperate magnetically with one or the other of the ferromagnetic armatures of the movable part.
• the stator assembly has a rectangular section.
• the stator assembly has a circular section.
• the moving assembly is constituted by an axis passing through the stator assembly and supporting at least one ferromagnetic armature having a section corresponding to the section of the yoke of the stator part.
• the electromagnetic actuator has two sets of independently connected excitation coils.
• each of the outstanding magnetic circuits is associated with an excitation coil that is suitably connected (in series or in parallel) with its neighbor, thereby defining a single electrical phase.
• the arrangement of the coils in the electrical phase is realized in such a way that the magnetic flux generated by the first coil is withdrawn from the current-free flow of the first remarkable magnetic circuit while the magnetic flux generated by the second coil is added to the flow without current of the second magnetic circuit remarkable.
• the actuator can be controlled using a single bipolar current.
• the actuator according to this preferred variant is single-phase and traversed by a current bipolar. This also makes it possible to reduce the number of power transistors and the cost of the electronics (at most 4 transistors).
• the current supplying the electrical phase of the actuator can be modulated, and this without necessarily having to change its polarity, in order to slow down or accelerate the movable member during its course from one end of the race to the next. the other. It has a better controllability of the actuator while maintaining a good current dynamics.
• This control mode makes it possible to set up a "soft landing” strategy and therefore drastically reduce the noise caused by the landing of the mobile part on the stator part.
• This type of actuator also has the particularity of grouping at its center the stator part, namely a ferromagnetic part comprising one or more permanent magnets but also one or more coils. This specificity makes it possible to concentrate the magnetic excitation fluxes in a localized and controlled zone. This is a particularity that can be exploited when integrating into at least one of the magnetic circuits of a remarkable remarkable position sensor, for example Hall effect or inductive type.
• the actuator comprises an elastic return system exerting a force on each of the ends of the movable member intended to keep the latter close to its mid-race and conferring on the actuator thus designated the mass system quality. -spring.
• the above-defined actuator with judiciously sized elastic elements, has two stable steady state of equilibrium positions and an increased dynamic of displacement.
• the actuator comprises two compression springs each exerting a balanced force on each of the two moving armatures. In this way, the movable armatures can advantageously be used not as a single magnetic member but also as a mechanical stop for the springs.
• the springs are placed on the same side of the movable member and each separated by a third part connected to the movable member.
• the elastic return system described here gives the mobile unit a maximum speed in the middle of the race, which is high over most of the race and almost zero in the vicinity of the ends of the race, so it should be noted that is quite adapted to the principle of the actuator described here. Indeed, the force against electro-motor being proportional by nature. the speed of the moving part and of a nature to slow down it, this one being reduced on a major part of the race or even quasi-null as soon as the race becomes relatively consequent, it makes it possible to reduce as much as possible the losses of nature to penalize the dynamics of the system.
• the structure has an extrusive geometric invariance and thus advantageously makes it possible to produce the magnetic circuit of the actuator in a soft laminated magnetic material.
• the structure may be polarized by two flat magnets placed symmetrically with respect to the main axis of the actuator.
• the actuator can be defined axisymmetrically with the aid of a single magnetic ring substantially radially magnetized.
• the electromagnetic actuator comprises a ring magnet axis of revolution collinear with the main axis of the actuator and magnetized substantially radially.
• the magnets distribute a magnetic field in the stator which then loops back into the air around the stator poles.
• the magnetic flux generated by the magnets describes a magnetic circuit that can be advantageously used during a magnetization phase. Therefore, it can be advantageously when the magnets are already integrated in the magnetic structure. In this way, it saves a certain time on the magnetization phase since a single polarized stator is required but also saves time on the assembly phases which are therefore simplified by handling magnets not magnetized.
• This type of actuator has a useful travel substantially equal to the sum of the air gap separating the so-called “lower” armature from the lower part of the stator assembly and the gap separating the "upper” armature from the upper part of the stator assembly.
• the mechanical stops defining the ends of races will have to be adapted.
• the mechanical stops of start and end of stroke will be realized by the direct contact of the ferromagnetic armatures on the ferromagnetic stator part.
• the mechanical stops will be realized by the addition of a non-magnetic third located between the ferromagnetic armatures and the ferromagnetic stator part.
• these third parties may for example be made by the mechanical addition of a part or by a deposit of material.
• the stator and / or mobile parts have a non-magnetic portion ensuring a residual air gap in the race ends.
• the mechanical stops may be subject to a positional offset and no longer be made directly between the armatures and the stator assembly.
• the mechanical stops are made between one or more members connected to the movable part and one or more members connected to the stator part.
• this device also allows adjustment of the useful stroke and the holding force without current at stable positions at the stroke ends.
• the mobile part is articulated about an axis of rotation substantially located in the center of the median plane of the structure.
• the two armatures are integral with a rotary axis and come into contact with the stator part by a beveling magnetic poles of the stator part ( Figure 11) or rotor.
• the angle of the bevels makes it possible to size the angular stroke of the actuator according to the needs of the designer.
• the magnetic structure remains substantially the same as for a linear actuation.
• the present variant can also be associated with an elastic return system, using for example, and not exclusively, compression springs or spiral springs.
• the electromagnetic actuator comprises at least one position sensor integrated in the stator structure.
• the electromagnetic actuator comprises at least one position sensor integrated in the mobile structure.
• the current and / or position information allows optimized control, and in particular minimization of the impact speed at the end of travel.
• FIG. 1 represents the shape of the variation of the force constant of an actuator according to the invention as a function of the position of the movable part
• FIG. 2 represents the shape of the variation of the profiles of forces without current, of the elastic return system and the coupling of these two forces evoked as a function of the position of the movable member
• FIG. 4 represents a sectional view of a variant of an actuator according to the invention
• FIG. 5 represents a sectional view of an actuator according to one particular variant of the invention
• FIG. 7 represents a sectional view of a variant of an actuator according to the invention in which an inductive sensor solution in the form of added coils is implemented ( 15,16) detecting the variations of magnetic flux flowing in the remarkable magnetic circuits. In doing so it is easy to deduce the position of the movable member
• Figure 8 shows a sectional view of a variant of an actuator according to the invention, defined in that it has a single coil and a 9 shows a sectional view of the actuator where the mobile part is in the up position
• FIG. 10 represents a sectional view of the actuator where the mobile part is in the low position
• Figure 12 shows the distribution of magnetic flux lines through the structure when the movable member is in the low position.
• FIG. 13 represents the distribution of the magnetic flux lines through the structure when the mobile member is in the up position.
• Figure 14 represents the distribution of the magnetic field when the moving part is centered on its path.
• the actuator presented by way of non-limiting example in FIG. 3 comprises a stator part consisting of parts made of soft ferromagnetic material (1,3).
• the piece (1) forms a core.
• the piece (3) forms a breech.
• This set defines a stator magnetic circuit polarized by two flat magnets (3a, 3b) introduced into the central part of the structure. These are magnetized substantially symmetrically relative to the plane perpendicular to the section plane of Figure 3 and passing through the main axis of the actuator.
• the cylinder head (3) extends on both sides of the core
• the parts constituting the stator part may be, for example, made of soft magnetic steel laminated iron type silicon or soft magnetic steel sintered type iron phosphorus to limit losses by eddy currents.
• a movable ferromagnetic part consists of 2 armatures (2a, 2b) distributed on either side of the stator part, and integral with a non-magnetic axis (11), made of non-magnetic stainless steel for example.
• Figure 14 shows a representation of the actuator in the middle of the race. In this position, the distribution of the field lines without current through the ferromagnetic structure is symmetrical with respect to the plane perpendicular to the plane of section and parallel to the axis. This position of unstable magnetic equilibrium is supported by the addition of two springs (7a, 7b) which are placed and prestressed so that the middle position of the race is mechanically stable without current.
• a fixed part (9a, 9b) which is the symbolic representation of a non-magnetic frame in which the present invention.
• the frame could be for example the motor housing and the shaft (11) would be integral with the valve to move.
• the movable moving part is integral with the axis (11) and is linearly guided by guiding devices that the example designates (10) as fitted bearings.
• FIG. 10 shows the low extremal position of the mobile part and in this case the upper armature (2a) is in contact with, or not far from the contact, the stator part. This stable position is maintained thanks to the very high current-free force in this contact or quasi-contact position.
• Figure 8 is then the counterpart of Figure 9 but this time for an axis in the high position and a low armature (2b) in contact with the stator part.
• Two coils (5a, 5b) are placed in two housings provided for this purpose.
• a first coil (5a) is wound on a pole portion (13) of the stator so that the winding axis is collinear with that of the movement.
• a second coil (5b) is installed on a second polar pole portion (14).
• the two coils are preferably connected together (in series or in parallel) to form a single phase, so that when a current flows in an arbitrarily positive direction in the phase, the magnetic flux generated by the electric current is added to the currentless flux generated by the magnets in the pole portion 13 and retract the flow without current generated by the magnets in the pole portion 14.
• an arbitrarily negative current in the phase will add the flow with current and without current in the pole portion 14 but retract into the pole portion 13.
• a negative current generates a magnetic flux that comes subtract from the flow without power.
• the holding force without current is amputated by an amount directly related to the intensity of the current flowing in the electrical phase. In doing so, it will correspond to a value of electric current allowing the restoring force generated by the spring system to take precedence over the holding force without current.
• the movable member will therefore leave this stable equilibrium position (13) without current to quickly gain speed and direct towards the other end of the race (14) and its second stable equilibrium position.
• the current flowing in the phase then becomes motor since the latter generates a magnetic flux to add to the flow without current on the appendix Polar 14.
• the overall speed of the movable member is then related to the stiffness of the springs, but also to the current flowing through the electrical phase.
• the current can cancel without the moving part leaving its second position of steady equilibrium without current (14).
• the race is made in the other direction.
• one or more position sensors integrated into the structure (as for example described in FIG. 7), or added to the structure, makes it possible to optimize the control of the actuator, and in particular the management of the actuator. the speed of impact of the moving part on the stator part, by a servo operation in a closed loop.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Power Engineering (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Reciprocating, Oscillating Or Vibrating Motors (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=35809704

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (74)

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• 2005
  • 2005-04-06 FR FR0503436A patent/FR2884349B1/fr not_active Expired - Fee Related
• 2006
  • 2006-04-06 EP EP06743652A patent/EP1875480B1/de not_active Expired - Lifetime
  • 2006-04-06 WO PCT/FR2006/000768 patent/WO2006106240A2/fr not_active Ceased
  • 2006-04-06 US US11/910,172 patent/US7898122B2/en not_active Expired - Fee Related
  • 2006-04-06 JP JP2008504807A patent/JP2008535472A/ja not_active Withdrawn
  • 2006-04-06 DE DE602006007696T patent/DE602006007696D1/de not_active Expired - Lifetime
• 2013
  • 2013-03-06 JP JP2013043896A patent/JP5735564B2/ja not_active Expired - Fee Related

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