Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H50/00—Details of electromagnetic relays
  • H01H50/16—Magnetic circuit arrangements
  • H01H50/18—Movable parts of magnetic circuits, e.g. armature
  • H01H50/20—Movable parts of magnetic circuits, e.g. armature movable inside coil and substantially lengthwise with respect to axis thereof; movable coaxially with respect to coil
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H50/00—Details of electromagnetic relays
  • H01H50/02—Bases; Casings; Covers
  • H01H50/021—Bases; Casings; Covers structurally combining a relay and an electronic component, e.g. varistor, RC circuit
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H50/00—Details of electromagnetic relays
  • H01H50/54—Contact arrangements
  • H01H50/546—Contact arrangements for contactors having bridging contacts

Definitions

• the present invention relates to an electromagnetic contactor.
• the invention relates to an electromagnetic contactor intended to be fixed on a support rail, in contact with other electrical devices.
• an electromagnetic contactor comprises:
• a magnetic circuit comprising a fixed part and a mobile part.
• Elastic means are provided to keep the fixed and movable parts apart in the absence of supply of the coil.
• a first call phase when the coil is supplied with current, the magnetic circuit tends to close, the moving part coming closer to the fixed part until these two parts are in contact.
• This so-called power call power is related to the number of ampere-turns of the coil, that is to say the product of the number of turns of the coil and the value of the current intensity in the coil.
• the magnetic circuit During a second holding phase, the magnetic circuit must remain in the closed position as long as the supply of the coil is present. In this second phase, the amperes-turns necessary level is much lower than in the call phase, because the gap is zero, and the magnetic forces are maximum.
• the contactors can be supplied with direct current or alternating current.
• This card makes it possible in particular to supply the coil with direct current, whatever the supply voltage, alternative or continuous.
• the card also increases the supply voltage range that can be used by the contactor.
• the card also makes it possible to reduce shocks during the call phase and consumption during maintenance. Because of the extra cost of the electronic card, this solution is reserved for medium and large devices, greater than 50 A.
• EP 0 751 545 discloses an electromagnetic contactor comprising:
• a coil for generating a magnetic field a magnetic circuit comprising a fixed part and a moving part, and
• an electronic card comprising means for controlling the supply of the coil, the electronic card being arranged horizontally above the fixed part of the magnetic circuit.
• This contactor is however intended for automotive application, in which it is possible to allow a large bulk of the contactor along the axis of movement of the movable part of the armature.
• this contactor comprises a movable armature which passes through the fixed armature and extends towards the rear of the contactor with respect to the coil.
• the present invention aims to provide a contactor to be fixed on a support, whose size is reduced.
• the present invention also aims to provide a contactor to meet the above criteria in an improved manner.
• the subject of the present invention is an electromagnetic contactor of the aforementioned type, characterized in that the contactor comprises an insulating housing comprising a rear part intended to be fixed on a support and in that the mobile part passes through the electronic card by an opening of the card and slide inside the coil
• Such a switch also provides the advantages mentioned above for an electronic card.
• the contactor comprises connection terminals of the coil being located in the plane of the electronic card.
• connection terminals makes it possible on the one hand to maintain connections of the power supply to the contactor made in the same manner as a conventional contactor, that is to say above the coil, and secondly to further limit the size of the contactor.
• the fixed and mobile parts of the magnetic circuit have substantially axisymmetric shapes.
• the axisymmetrical structure of the magnetic parts offers a better performance than a conventional flat structure.
• the fixed and mobile parts have opposite conical portions, one convex and the other concave.
• the electronic card makes it possible to limit the shocks during the call phase and therefore to considerably reduce the contact surfaces of the two armatures without exposing the magnetic circuit to premature wear, and without increasing the time of conjunction.
• the duration of the call phase with the contactor according to the invention is of the same order as that of a contactor of the same range, having no reduced call power.
• the fixed and mobile parts are made in massive elements.
• the massive structure of the magnetic parts allows an optimization of the forms and the choice of the materials and to use processes of production of large series, like the stamping, the cold stamping, or the cutting. These provisions thus make it possible to reduce the costs and the complexity of the manufacture.
• the fixed part forms a housing in which the coil is received.
• the fixed part of the magnetic circuit comprises at least one lateral opening.
• the fixed part of the magnetic circuit comprises:
• a wall comprising a passage opening of the movable part at a second end of the cylindrical portion.
• the lateral opening is constituted by a notch in the edge of the cylindrical portion forming the second end of the cylindrical portion.
• the fixed part of the magnetic circuit comprises:
• This arrangement makes it possible to produce the fixed part of the magnetic circuit from two simple shapes that are easier to produce.
• this arrangement facilitates the assembly of the coil in the fixed part of the frame. It allows to facilitate the production of the part, and to realize this production in large series.
• the elements of the contactor are stackable.
• This arrangement facilitates the assembly of the contactor.
• the stacking can be performed by a simplified automated process.
• the power supply control means of the coil are arranged to supply the DC coil, whether the supply voltage of the contactor is alternating or continuous.
• the means for controlling the supply of the coil comprise means for determining a current value making it possible to close the contactor or to keep the contactor closed, and means making it possible to limit the average value of the supply current. from the coil to the determined value.
• Figure 1 is an exploded perspective view of a contactor according to the invention.
• Figure 2 is an exploded perspective view of the contactor of Figure 1, the parts constituting the housing having been removed.
• Figure 3 is a perspective view in partial section of the magnetic circuit.
• FIG. 4 is a diagram of the electrical circuit of the electronic board of the contactor of FIG.
• FIG. 5 is a flowchart of operation of the control means constituted by the electronic card.
• Figure 6 is a partial perspective view of a second contactor according to the invention.
• FIG. 7 is another partial perspective view at a second angle of view of the contactor of FIG.
• FIG. 8 is a detail view, in perspective of the fixed part of the magnetic circuit of the contactor of FIG. 6.
• an electromagnetic contactor comprises an insulating housing comprising a rear portion 2, intended to be fixed on a support, and a front portion 3, intended to be fixed on the rear part 2. On the front part 3 of the housing are fixed fixed contacts not shown.
• the insulating housing also comprises a terminal block 4 intended to be fixed above the front part, and having connection terminals 5 intended to be connected to the fixed contacts.
• the housing parts form a housing in which are received:
• a coil 6 for generating a magnetic field fixed to the housing, and
• a magnetic circuit having a fixed portion 7 relative to the housing and a movable portion 8 relative to the housing.
• a movable contact carrier 9 is integrally mounted with the movable portion 8 of the magnetic circuit.
• the contact carrier 9 comprises movable contacts intended to be in contact with the fixed contacts, or separated from these fixed contacts, according to the position of the movable part 8, to close or open an electrical power circuit.
• Elastic means consisting of two springs 10 are provided to keep the fixed parts 7 and mobile 8 apart in the absence of supply of the coil 6.
• the contactor comprises means for controlling the supply of the coil 6 in AC or DC voltage, constituted by an electronic card 11.
• This electronic card 11 of the type described in EP 0 789 378, is arranged in interface between the external power supply and the power supply of the contactor coil.
• This electronic card 11 is arranged horizontally above the fixed part 7 of the magnetic circuit, the mobile part 8 passing through the electronic card through an opening of the card 12 and sliding inside the coil and the fixed part 7.
• connection terminals of the coil of the terminal block 5 are located in the plane of the electronic card.
• the fixed and mobile parts 8 and 8 of the magnetic circuit have an axisymmetric shape with respect to an axis A, which coincides with the axis of the coil 6.
• the fixed part 7 of the magnetic circuit comprises:
• a body 13 forming: a cylindrical portion 14, a bottom 15 at a first end of the cylindrical portion 14, and
• a cover 16 forming a wall comprising a passage opening 17 of the mobile part 8 intended to be positioned at a second end of the cylindrical portion 14.
• the body and the cover define a housing in which the coil 6 is received.
• the passage opening 17, arranged around the axis A. makes it possible to ensure the penetration of the mobile part in the coil 6.
• the movable portion 8 comprises a cylindrical portion intended to enter the passage opening 17.
• the fixed parts 7 and mobile 8 have conical portions facing.
• the fixed portion comprises a convex conical portion 18 disposed on the bottom 15 of the body 13.
• the movable portion 8 has a concave conical portion 19.
• the concave portion could be positioned on the fixed portion and the convex portion on the moving part.
• the two conical portions 18, 19 are of a shape adapted to provide an air gap between them when the two fixed and moving parts are in touch with.
• the flat end ends 20, 22 of the two conical parts do not come into contact, when the fixed and moving parts are in contact.
• the fixed parts 7 and mobile 8 are made in solid elements.
• the body 13 of the fixed part 7 of the magnetic circuit comprises at its upper edge, on which the cover 16 is positioned, indentations 24. These notches allow the outward passage of the body of connection means of the coil, in particular wires or other portions of conductors.
• the contactor comprises substantially the same elements as in the first embodiment.
• a single return spring 10 is present to separate the armatures in the rest position, this spring being positioned around the movable armature.
• the electronic card 11 comprises an opening constituted by a cutout 12 opening on the edge of the electronic card 11 through which the movable portion 8 of the magnetic circuit passes through the plane of the electronic card.
• the connection terminals of the coil of the terminal block 5 are located in the plane of the electronic care.
• the terminal block 5 is a removable terminal block comprising metal tabs 26 intended to be received in elastic lyres 27 mounted on the card 11 to provide the electrical connection.
• FIG. 8 shows the embodiment of the indentations 24 at the upper edge of the fixed part of the armature, allowing the passage of the coil connection means comprising flexible wires or rigid conductor portions 25.
• the electronic card used by the two previously described contactors comprises a filtering component F and a rectifier component Rd making it possible to transform an alternating voltage into a DC voltage.
• the rectifier component Rd may comprise a diode bridge.
• the electronic card comprises means for determining a current value for closing the contactor or maintaining the contactor closed, and means for limiting the average value of the supply current of the coil to the determined value.
• the coil 6 of the contactor is powered by a step-down chopper device consisting of a power transistor TR, bipolar transistor, MOSFET or IGBT, operating in "all or nothing", controlled by a signal amplitude modulation amplitude "PWM" (pulses width modulation) generated by a control device constituted here by a microcontroller ⁇ C; this control device could also be constituted by any other specific logic circuit.
• PWM pulse width modulation
• the frequency of this signal is fixed and the duty cycle, that is to say the ratio between the conduction time and the signal period, is adjusted by the microcontroller ⁇ C.
• the coil 6 is connected in series with the power transistor TR, and a resistor R1 used for the measurement of the current.
• the microcontroller ⁇ C is powered by a power supply component UR delivering a controlled voltage.
• the microcontroller ⁇ C takes as input:
• a signal proportional to the supply voltage of the contactor provided by a voltage divider formed by two resistors R2 and R3.
• the average voltage across the coil of the contactor is the product of the duty cycle by the source voltage.
• the adaptation of the duty ratio of the step-down chopper device as a function of the input voltage level makes it possible to feed the coil with a determined constant average value voltage regardless of the power supply value of the contactor. This value can be set to the minimum call threshold during the call phase and the minimum hold threshold during the hold phase.
• the maximum duty cycle of 100% is reached for the minimum value of the voltage power supply within the operating range of the contactor.
• the duty cycle is adjusted automatically according to the current to be controlled.
• the coil is further connected antiparallel to a freewheeling diode D.
• the freewheeling diode keeps the magnetic energy stored in the coil and limits the overvoltages caused by the switching off of the contactor control. It is thus possible to keep the closing of the contactor in case of micro-cuts or voltage dips, and to perform a clipping of the voltage. These provisions make it possible to mitigate the failures of the supply network.
• Figure 5 illustrates the operation of the card, when a supply voltage is established across the contactor.
• a supply voltage is established, it is subjected to filtering by the filtering component 12, then a rectification is performed by the rectifier component 13, in a first step E1.
• a second step E2 the nature and the level of the supply voltage are detected.
• the minimum call threshold is the minimum level of voltage across the coil 6 sufficient to trigger the detachment and closure of the magnetic circuit. With this voltage level, the travel of the moving contacts has sufficient momentum to close the power circuit in good conditions, defined by normative constraints.
• a PWM signal is generated to control the supply of the coil to the minimum call threshold.
• a test is performed to identify whether a change of slope and the maximum intensity in the coil are reached. If this is not the case, we stay in step E4.
• a regulation of the current at the minimum threshold of maintenance is operated.
• the minimum holding threshold is the level of current just sufficient to keep the electromagnet closed, taking into account the mounting positions of the contactor, its resistance to shock and vibration, and the number of auxiliary contacts associated, that is to say mechanical loads.
• This control is operated until a contactor lock command is received, i.e. until the voltage drops below the minimum contactor supply voltage, which is shown by step E7.
• the control logic provides control of the voltage and current during the call phase which reduces the shock and wear of mechanical parts and a current control during the maintenance phase of the contactor, which has the advantage of reducing the power dissipated.
• the circuit board 11 allows the contactor to operate over a wide alternating or continuous supply voltage range.
• the ratio between the minimum and maximum terminals of a supply voltage range is between 1.5 and 3.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Details Of Connecting Devices For Male And Female Coupling (AREA)
• Relay Circuits (AREA)
• Switch Cases, Indication, And Locking (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2006
  • 2006-05-09 FR FR0604083A patent/FR2901056B1/fr active Active
• 2007
  • 2007-04-16 US US12/298,211 patent/US7902947B2/en active Active
  • 2007-04-16 ES ES07731303.9T patent/ES2645241T3/es active Active
  • 2007-04-16 CN CN2007800012825A patent/CN101356613B/zh active Active
  • 2007-04-16 WO PCT/FR2007/000637 patent/WO2007128892A1/fr active Application Filing
  • 2007-04-16 EP EP07731303.9A patent/EP2016604B1/de active Active

Non-Patent Citations (1)

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