Classifications

• • 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
  • H01F7/081—Magnetic constructions
• • 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
• • 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
  • H01F7/127—Assembling
• • 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
  • H01F7/1607—Armatures entering the winding
• • 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

Definitions

• Electromagnetic actuator and method of manufacturing such an actuator are Electromagnetic actuator and method of manufacturing such an actuator
• the present invention relates to an electromagnetic actuator.
• the actuator comprises a ferromagnetic carcass, extending in a longitudinal direction and having a height in a vertical direction perpendicular to the longitudinal direction.
• the actuator comprises two electromagnetic coils disposed inside the carcass, each comprising at least one winding around the longitudinal direction.
• the actuator also comprises a ferromagnetic member disposed between the coils and a ferromagnetic plunger subjected to a magnetic field generated by the coils, the ferromagnetic plunger being movable in the longitudinal direction and able to be immobilized according to three distinct longitudinal positions depending on the field generated. by the coils.
• the invention also relates to a method of manufacturing such an electromagnetic actuator.
• Document EP 2 250 651 discloses an electromagnetic actuator comprising two coils, a plunger able to be immobilized in three positions, namely two extreme positions facing the coils and an intermediate position between the coils.
• the plunger comprises a magnet and two members for guiding the flow of the magnet to the carcass, in order to stabilize the plunger in its intermediate position.
• the actuator has an additional coil for compensating the field of the magnet when the plunger is in a position other than its intermediate position.
• the object of the invention is therefore to provide a three-position actuator having a reduced cost and volume.
• the subject of the invention is an electromagnetic actuator, in which the ferromagnetic member is integral with the carcass and has, in the vertical direction, a dimension greater than one sixth of the height of the carcass, preferably greater than a quarter of said height, more preferably greater than one-third of said height, the ferromagnetic member being furthermore situated at a distance less than a quarter of a distance in the longitudinal direction between the two coils, with respect to a median plane perpendicular to the longitudinal direction and located midway distance between the two coils, so as to guide the magnetic flux created by the coils to the carcass.
• the electromagnetic actuator comprises one or more of the following characteristics, taken individually or in any technically possible combination:
• each electromagnetic coil comprises an armature, the or each winding being fixed to the corresponding armature, and the ferromagnetic member is fixed to the two armatures;
• the ferromagnetic member comprises, in the longitudinal direction, a passage recess of the plunger
• the ferromagnetic member extends from ⁇ recess to the carcass
• the recess has a peripheral edge, and the ferromagnetic member comprises at least one flange extending from said peripheral edge;
• the flange extends in the longitudinal direction
• the ferromagnetic member comprises at least one outer projection, the or each outer projection being disposed outside the carcass and at least partially in contact with the carcass;
• the ferromagnetic member comprises at least one inner projection, the or each inner projection being disposed within the carcass and at least partially in contact with the carcass;
• the projections are oriented in the longitudinal direction.
• the invention also relates to a method for manufacturing an electromagnetic actuator, the method comprising the steps of:
• each coil comprising at least one winding around the longitudinal direction
• the ferromagnetic member is integral with the carcass and has, in the vertical direction, a dimension greater than one sixth of the height of the carcass, preferably greater than one quarter of said height, more preferably greater than one third of said height, the ferromagnetic member being furthermore located at a distance less than a quarter of a spacing in the longitudinal direction between the two coils, with respect to a median plane perpendicular to the direction longitudinal and located midway between the two coils, so as to guide the magnetic flux created by the coils to the carcass.
• the manufacturing method comprises the following characteristic: during step c), the ferromagnetic member is fixed by laser welding to the carcass.
• FIG. 1 is a perspective view of an actuator according to the invention, comprising a ferromagnetic carcass, two electromagnetic coils, a ferromagnetic plunger movable in translation and a guide member of a magnetic flux generated by the coils,
• FIG. 2 is an exploded perspective view of the actuator of FIG. 1;
• FIG. 3 is a perspective view of the flow guide member of FIG.
• FIG. 4 is a flowchart of a manufacturing method according to the invention.
• an electromagnetic actuator 10 comprises a carcass
• the electromagnetic actuator 10 comprises a rod 26 for guiding the plunger.
• the electromagnetic actuator 10 is for example used to establish or section a current. It is used in particular to control the direction of rotation of an electric motor.
• the carcass 12 extends in a longitudinal direction X and has a generally cubic shape with rounded edges.
• This carcass 12 is preferably made of a ferromagnetic material.
• the carcass 12 comprises two U-shaped portions 28, 30 and two magnetic tips 32, 34.
• the carcass 12 has a first height H1 in a vertical direction Z perpendicular to the longitudinal direction X.
• the two electromagnetic coils 14, 16 are disposed inside the carcass 12.
• the two coils 14, 16 are, for example, coaxial with respect to an axis in the longitudinal direction X.
• Each electromagnetic coil 14, 16 comprises a respective winding 36, 38.
• the two coils 14, 16 are spaced from each other by a spacing E in the longitudinal direction X, as shown in FIGS. 1 and 2.
• the two armatures 18, 20 each hold a respective winding 36, 38 and fix the coils 14, 16 to the carcass 12.
• the armatures 18, 20 are preferably made of plastic.
• the armatures 18, 20 preferably form a single plastic part around which are wound two copper son to form the respective windings 36, 38.
• Each armature 18, 20 is of revolution about the axis of the coils 14, 16 and has a U-shaped section open towards the outside in a vertical plane containing the axis of the coils, as can be seen in FIGS. 1 and 2
• the armatures 18, 20 are then able to receive the windings 36, 38.
• the armatures 18, 20 are fixed with respect to the carcass 12.
• Each armature 18, 20 forms at its center a substantially cylindrical tube 39 and extending in the longitudinal direction X, and within which the plunger 22 is slidable, as shown in Figures 1 and 2.
• the plunger 22 is subjected to a magnetic field generated by the coils 14, 16.
• This plunger 22 is movable in translation along the axis of the coils 14, 16.
• the plunger 22 comprises a ferromagnetic material, and is preferably made of said ferromagnetic material.
• the plunger 22 is of revolution about the longitudinal direction X, and is arranged around the guide rod 26.
• the plunger 22 has a cylindrical shape in its median portion in the longitudinal direction X and two convex conical shapes at each of its ends in the longitudinal direction X, as shown in Figures 1 and 2.
• the plunger 22 is able to be immobilized according to three distinct longitudinal positions, namely two extreme positions facing the coils 14, 16 and an intermediate position between the coils 14, 16.
• the intermediate position of the plunger 22 belongs for example to a median plane perpendicular to the longitudinal direction X and situated midway between the two coils 14, 16.
• the guide member 24 is disposed between the coils 14, 16 and is fixed relative to the carcass 12.
• the guide member 24 preferably passes through the carcass 12 to be fixed thereto.
• the guide member 24 has, in the vertical direction Z, a second height H2 greater than one sixth of the first height H1 of the carcass 12, preferably greater than one quarter of said first height H1, more preferably greater than one third of said first height H1.
• the second height H2 of the guide member 24 is greater than the first height H1 of the carcass 12, as shown in Figures 1 and 2.
• the guide member 24, as shown in Figure 3, comprises a main portion 40, a recess 42, first 44A and second 44B edges.
• the guide member 24 has upper outer projections 46A and lower 46B, and inner projections 48.
• the outer outer projection 46A is intended to be disposed outside and above the carcass 12 in a perpendicular vertical direction Z in the longitudinal direction X
• the lower outer projection 46B is intended to be disposed outside and below the carcass 12.
• the inner projections 48 are intended to be disposed inside the carcass 12.
• the guide member 24 is made of a ferromagnetic material, and is capable of guiding the magnetic flux generated by the coils 14, 16.
• the guide member 24 is, for example, in the form of a ferromagnetic plate disposed in a plane substantially perpendicular to the longitudinal direction X.
• the plane of the guide member 24 is located, in the longitudinal direction X, at a distance of distance less than a quarter of the distance E with respect to a median plane P perpendicular to the longitudinal direction and located midway between the two coils 14, 16.
• the plane of the guide member 24 coincides with the median plane P.
• the guide member 24 is disposed at the intermediate position of the plunger 22 in the direction longitudinal X.
• the guide rod 26, visible in Figure 2 is for example plastic. It traverses the plunger 22 from one side to the other in the longitudinal direction X.
• the guide rod 26 is, for example, fixed integrally to the plunger 22.
• the guide rod 26 has a substantially cylindrical shape.
• the guide rod 26 is able to guide the plunger 22, so that it moves only axially in the longitudinal direction X.
• the guide rod 26 guides the plunger 22 so that it does not touch the inner wall of the tube 39 formed by the frames 18, 20, to reduce friction.
• Each U-shaped portion 28 has 30 walls, namely a first transverse wall 50 perpendicular to the longitudinal direction X, an upper longitudinal wall 52 and a lower longitudinal wall 54.
• Each transverse wall 50 has a hole 56 for passing through.
• a tip 32, 34 corresponding.
• the two U-shaped portions 28, 30 form, when they are assembled, a fixed frame. This frame forms a support for fixing the other elements of the electromagnetic actuator 10.
• the end pieces 32, 34 of the carcass 12 are positioned at the longitudinal ends of the tube 39 formed by the armatures 18, 20. These end pieces 32, 34 make it possible to limit the displacement of the plunger 22 when it is in one of its positions. extremes facing one of the coils 14, 16. These tips 32, 34 and form stops. These tips 32, 34 are coaxial with the axis of the coils 14, 16, which is also the axis of translation of the plunger 22.
• Each end piece 32, 34 has a concave conical shape oriented towards the inside of the actuator 10 in the longitudinal direction X. Otherwise, the concave shape of the end pieces 32, 34 is oriented towards the plunger 22. These conical shapes are complementary to the surfaces. convex cones of the plunger 22, as shown in Figures 1 and 2.
• the end pieces 32, 34 preferably comprise at least one ferromagnetic part, in order to better guide a magnetic flux produced by the coils 14, 16.
• Each end piece 32, 34 has a through-hole 57 that is longitudinal to allow the guide rod 26 to slide, and to limit the substantially radial displacements of the guide rod 26 as shown in FIG.
• the main part 40 forms the central part of the member 24. It is preferably flat and in the longitudinal direction X. It extends from the recess 42, between the two frames 18, 20 to the ends of the carcass 12.
• the recess 42 has a peripheral edge 58 in the plane of the guide member 24 perpendicular to the longitudinal direction X.
• the recess 42 is formed in the main part 40. It is sufficiently wide in a radial direction perpendicular to a longitudinal direction X to allow the passage of the plunger 22. This recess 42 is oriented in the longitudinal direction X.
• the recess 42 has, in the radial direction, an internal diameter D1 adjusted to the outer diameter D2 of the plunger 22 in this radial direction and to a mechanical tolerance close to allow the plunger 22 to slide, as shown in FIG.
• Each flange 44A, 44B extends from the peripheral edge 58 of the recess, the first flange 44A in one direction and the second flange 44B in the other direction, along the longitudinal direction X, as visible in FIG. In the example of FIGS. 1 and 2, the flanges 44A, 44B fit into the two reinforcements 18, 20 in the longitudinal extension of the tube 39, so that the plunger 22 slides easily inside the tube 39 , the recess 42 and the flanges 44A, 44B.
• the outer projections 46A, 46B are arranged outside the carcass 12 and at least partially in contact with the carcass 12.
• the guide member 22 preferably comprises two outer projections 46A, 46B, namely the upper outer projection 46A. and the lower outer projection 46B.
• each outer projection 46A, 46B is adapted to be in contact with each of the two parts 28, Forming the carcass 12.
• Each outer projection 46A, 46B is, for example, in the form of a flat strip fixed perpendicular to the longitudinal direction, pressed against the outer surface of the carcass 12, as shown in FIG.
• the inner projections 48 are disposed within the carcass 12 and at least partially in contact with the carcass 12. There are preferably two inner projections 48, one upper and one lower. These projections are oriented in the longitudinal direction X as can be seen in FIG.
• Each inner projection 48 is, for example, in the form of a lug intended to be in contact with the inner surface of the carcass 12.
• the outer projections 46A, 46B and the inner projections 48 are, for example, arranged to take the carcass 12 sandwiched. The member 24 is then in contact with both the inner face and the outer face of the carcass 12.
• the initial step 100 consists in arranging the guiding member 24, provided with its flanges 44A, 44B, with its external projections 46A, 46B and its internal projections 48.
• the member 24 is disposed at the median plane perpendicular to the axis of the coils 14, 16.
• the guide member 24 is preferably a ferromagnetic plate that is arranged perpendicularly to the longitudinal direction X.
• the flow guiding member 24 is formed, for example, by sintering two pieces, each U-shaped in the longitudinal direction X, and the U-shaped pieces being oriented in opposite directions to form a general shape in an H extending in the longitudinal direction X.
• the following step 1 consists in arranging the electromagnetic coils 14, 16, fixing them to the member 24.
• the armatures 18, 20 of the electromagnetic coils are then overmolded around the flux guiding member 24.
• the armatures 18, 20 preferably form a single plastic part overmolded around the guiding member 24.
• the guide member 24 is placed in a central position in a mold which then serves to overmold the reinforcements 18, 20.
• the windings 36, 38 are then made by winding copper wires around the reinforcements 18, 20, the latter having been previously fixed to the guide member 24.
• step 120 the guide rod 26 is placed in the ferromagnetic plunger 22 and then the guide rod 26 - plunger 22 assembly in the tube 39 formed by the armatures 18, 20.
• step 130 the carcass 12 is made by placing the magnetic tips 32, 34, which slide the guide rod 26, in the U-shaped portions 28, 30, which fit together to form the carcass. 12.
• the parts 28, 30 are during their assembly, sandwiched by the guide member 24 by means of the outer projections 46A, 46B and inner 48.
• the guide member 24 is then fixed to the carcass 12 by laser welding.
• the magnetic tips 32, 34 are attached to the U-shaped portions 28, also by laser welding.
• one of the two electromagnetic coils 14, 16 is electrically energized so as to generate a magnetic field of attraction of the plunger 22.
• the other electromagnetic coil 14, 16 is not electrically powered or is electrically powered to generate a repulsive magnetic field of the plunger 22.
• the generated magnetic field or fields produce a magnetic flux which is guided by the ferromagnetic parts of the electromagnetic actuator 10, that is to say by the carcass 12, the plunger 22 and the guide member 24. This arrangement minimizes the leakage flow and improves the efficiency of the electromagnetic actuator 10.
• the displacement of the plunger 22 towards its intermediate position is for example ensured by a return spring, not shown.
• a return spring avoids feeding the electromagnetic coils 14, 16 to move the plunger 22 to its intermediate position.
• the displacement of the plunger 22 towards its intermediate position is obtained by the generation of magnetic fields of repulsion or of fields of attraction of the plunger 22, these fields of repulsion or attraction being generated by the two electromagnetic coils 14, 16 which are then electrically powered.
• the plunger 22 then moves inside the tube 39, the recess 42 and the flanges 44A, 44B, while being guided by the sliding of the guide rod 26 inside the end pieces 32, 34.
• the guide member 24 makes it possible to ensure a better mechanical stability of the plunger 22 in its intermediate position, the guide member 24 improving the guidance of the magnetic flux towards the carcass 12 from the coils 14, 16.
• the flanges 44A, 44B advantageously improve the stability of the plunger 22 in its intermediate position by guiding more the flows from the coils 14, 16 to the carcass 12.
• the orientation of the flanges 44A, 44B parallel to the translation axis of the plunger 22, that is to say in the longitudinal direction X, further improves this flow guidance by minimizing the reluctance between the plunger 22 and the main portion 40 of the guide member.
• the outer projections 46A, 46B further improve the stability of the plunger 22 in its intermediate position by improving the flow guidance.
• the arrangement of the outer projections 46A, 46B in the longitudinal direction X parallel to the longitudinal walls of the carcass 12 further improves this flow guidance by minimizing the reluctance between the carcass 12 and the main portion 40 of the guide member.
• the ferromagnetic member 24 allows, by its large radial dimensions and by its arrangement between the two electromagnetic coils 14, 16, to best guide the magnetic flux produced by the coils 14, 16, the plunger 22 is attracted to its position intermediate. This thus improves the stability of the intermediate position of the plunger 22 without resorting to other devices, such as the magnet and the additional coil of the actuator of the state of the art.
• the ferromagnetic armatures 18, 20 make it possible to fix the coils 14, 16 so that they each exert a magnetic field for controlling the position of the plunger 22.
• the overmolding of the reinforcements 18, 20 allows a better coaxial positioning of the coils 14, 16 with respect to the translation axis of the plunger 22 in the longitudinal direction X.
• the shape of the plunger 22 with its two convex conical shapes at each of its ends in the longitudinal direction X makes it possible to reduce the ferromagnetic mass embedded in the actuator 10, and also to reduce a resistance force diagram.
• the ferromagnetic member 24 extends from the recess 42 to the carcass 12, makes it possible to best guide the magnetic flux to the carcass, and reduces the magnetic reluctance of the whole assembly. the electromagnetic actuator 10.
• the electromagnetic actuator 10 makes it possible to improve the stability of the intermediate position of the plunger 22 while presenting a reduced cost and volume compared to the electromagnetic actuator of the state of the art.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Electromagnets (AREA)
• Reciprocating, Oscillating Or Vibrating Motors (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2013
  • 2013-10-21 FR FR1360246A patent/FR3012251B1/fr active Active
• 2014
  • 2014-10-20 WO PCT/EP2014/072429 patent/WO2015059086A1/fr active Application Filing
  • 2014-10-20 JP JP2016525075A patent/JP6797684B2/ja active Active
  • 2014-10-20 CN CN201480052277.7A patent/CN105580094B/zh active Active
  • 2014-10-20 US US14/917,163 patent/US9704635B2/en active Active
  • 2014-10-20 EP EP14789805.0A patent/EP3061103B1/de active Active

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