Compact electrical contactor with low contact resistance

Abstract

The invention relates to an electric contactor comprising a fixed contact (600) and a movable contact (500) driven by a carriage (400), and an electric motor (100) which controls the reversible movement of the movable contact (500) between a maximum approaching position P2 in which the movable contact (500) is driven by the carriage (400), and an open position P1 in which the movable contact (500) is driven by the carriage (400). Establishing mechanical and electrical contact with the fixed contact (600); in the open position, the contacts (500, 600) are farthest spaced from each other, the travel of which comprises: a movement area (1) in which the movable and fixed contacts (500, 600) are spaced from each other; the conductive surface of the movable contact (500) is pressed against the conductive surface of the fixed contact (600), characterized in that the electric motor (100) drives a mechanism with a position-dependent deceleration coefficient, having a deceleration coefficient CI at the interface between the movement region (1) and the contact region (2) of the contacts (500, 600), the deceleration coefficient CI is lower than the deceleration coefficients CI1 and CI2 at the ends of the movement region (1) and the contact region (2).

Description

Technical Field

[0001] The invention relates to a circuit breaker consisting of a device for controlling the closing and opening of an electric circuit of a high-voltage power source, in particular a battery.

[0002] Electric motor vehicles require batteries with relatively high voltages, typically 400 or even 800 volts. Therefore, for safety reasons, certain vehicle components must be able to automatically disconnect from the power supply in the event of an accident, a prolonged stop, or when the hood is opened, to avoid the risk of accidents to the user.

[0003] Typically, expensive and relatively heavy electromagnetic relays are used for this disconnection.

[0004] There have also been proposed electrical switches of the circuit breaker type, in which a contact strip is moved by an electromechanical actuator between a closed position, in which it ensures electrical continuity between two contact pins, and an open position, in which these two pins are electrically isolated.

[0005] Such electrical circuit breakers must not only ensure that contacts are made with very low resistance, but must also accommodate arcing that may occur when contacts are not perfectly established. Various solutions for extinguishing arcs or preventing arc formation have been proposed in the prior art. Background Art

[0006] In the prior art, US Patent No. 9859078B2 is known, describing an electromagnetic relay comprising a contact plate formed from a single continuous metal member having a first portion having a first thickness and a second portion having a second thickness thinner than the first thickness. This relay applies a magnetic field from two directions transversely to a fixed contact point and a movable contact point b to generate a Lorentz force, thereby extinguishing the arc generated during discharge. This solution is not very satisfactory because it requires additional, complexly controlled electromagnetic components to perform the function of preventing the formation of discharge arcs.

[0007] Patent US8514037 or patent US9336965 propose similar solutions using the Lorentz force.

[0008] Patent US10777374 provides a switchgear including a first circuit breaker mechanism and a second circuit breaker mechanism. The first circuit breaker mechanism is located in a current output path from a DC power supply, and the second circuit breaker mechanism is connected in parallel with the first circuit breaker mechanism located in the current output path from the DC power supply. When supplying the output current from the DC power supply, the second circuit breaker mechanism is connected before the first circuit breaker mechanism, and when interrupting the current output from the DC power supply, the second circuit breaker mechanism is disconnected after the first circuit breaker mechanism. To prevent arc discharge, the solution proposes including a capacitor between the DC power supply and the second circuit breaker mechanism, and connecting a discharge unit in parallel with the capacitor to release the charge stored in the capacitor when the output current of the DC power supply is interrupted. This solution also involves adding additional bulky components to reduce arc discharge.

[0009] International Patent Application WO2006024718 proposes a device for controlling the closing and opening of a battery circuit. The device comprises a first terminal intended to be connected to the battery and a second terminal intended to be connected to the circuit to be powered. Each terminal comprises a contact pin and a contact strip, which is intended to engage the pin to close the circuit and to move away from the pin to disconnect it. The contact strip is carried by a piston, which is movable against the action of a spring and guided within the housing. The contact strip is controlled by a disk integral with a gear driven by a worm that is keyed to the output shaft of an electric motor with a reduction gear. The disk has cams arranged on its radius, with one cam located near the disk's periphery and a second cam located near the disk's axis of rotation.

[0010] US Patent No. 9,548,174 describes a contactor comprising a current-carrying contact and a coupling element. The coupling element includes conductive pads for engaging the current-carrying contact and a contact jumper extending between the conductive pads. An actuator assembly moves the coupling element between a closed position, in which the conductive pads of the coupling element engage the current-carrying contact, and an open position, in which the conductive pads of the coupling element disengage from the current-carrying contact. When the actuator assembly is near or in the closed position, an electromagnetic force is generated between the contact jumper and the conductive pads to counteract the electromagnetic repulsive force generated between the current-carrying contact and the conductive pads.

[0011] European patent EP1680793B1 describes an alternative solution for controlling the disconnection and closing of a battery circuit, characterized in that the circuit comprises a terminal connected to a post, a contact rod carried by a piston movable against the action of a spring, an electric motor with a gearbox kinematically connected to the piston, and means for controlling the electric motor in one direction of rotation and in an opposite direction, rotation in one direction controlling the contact of the rod with the post and rotation in the opposite direction moving the rod away from said post.

[0012] Patent application WO2006024718 describes another solution for a battery disconnection and circuit closure device, in which a geared motor controls the displacement of a piston terminated by a contact strip, which is applied to the piston's shoulder by a spring. This spring tends to keep the contact strip at a certain distance from two posts designed to cooperate to close the circuit. However, this solution does not solve the problem of arcing, and may even increase it, as arcing can occur at both ends of the strip.

[0013] Disadvantages of existing technology

[0014] Most prior art solutions are unable to combine good dynamics in the contact approach phase with high contact forces without involving complex, bulky mechanisms.

[0015] The double contact solution is not entirely satisfactory because, in practice, due to manufacturing tolerances and local deformations caused by wear, the contacts are rarely of the overlapping surface type, which means that the contact surface is often smaller than expected and produces a higher resistance than expected. The use of solenoid-type actuators, as is very common in the prior art, produces a limited force at the contacts, which makes it impossible to achieve very low contact resistance when space and mass are the main issues.

[0016] For example, an electrical contactor with double contacts and an associated solenoid valve actuator results in a relatively high contact resistance, which therefore limits the contactor's ability to carry high currents (a typical contact resistance of 300 μΩ represents a loss of 18.75 W at 250 A). Summary of the Invention

[0017] The object of the present invention is to overcome the disadvantages of the prior art and, in its most general sense, to propose an electric contactor having the features stated in claim 1 .

[0018] According to a contactor of the present invention, the contactor specifically comprises a fixed contact piece and a movable contact piece driven by a bracket, and an electric motor, which controls the reversible movement of the movable contact piece between a maximum approach position P2 and a disconnection position P1: in the maximum approach position, mechanical and electrical contact is established with the fixed contact piece; in the disconnection position, the contacts are spaced farthest apart from each other, and their stroke includes: a moving area, in which the movable contact piece and the fixed contact piece are spaced apart from each other; and a contact area, in which a conductive surface of the movable contact piece is pressed against the conductive surface of the fixed contact piece, characterized in that the electric motor drives a mechanism whose deceleration coefficient varies with position, and has a deceleration coefficient C at the interface between the moving area (1) and the contact area of ​​the contact piece. I , the deceleration coefficient C I Lower than the deceleration coefficient C at the end of the movement area (1) and the contact area I1 and C I2 .

[0019] According to a variant, the contactor also has the following features, alone or in combination:

[0020] - The electric motor is connected to the carriage supporting the movable contact by a direct push-pull drive.

[0021] - The movable contact is formed by the end of a conductive flexible busbar

[0022] - the movable contact is moved by a rotatable bracket, one end of which is connected to the movable contact and is hinged about a pivot located at its other end, the flexible busbar having a second end attached to the contactor housing to form an electrical connection terminal, and wherein the position-dependent reduction coefficient mechanism is coupled to the movable bracket

[0023] -The movable contact is moved by a linear motion carriage

[0024] - the electric contactor includes a thrust spring inserted between the bracket and the movable contact

[0025] - the movable contact supports a conductive pad that cooperates with a conductive pad supported by the fixed contact

[0026] - The movable contact is provided with two tongue-shaped parts supporting the conductive pad and the sacrificial pad respectively

[0027] - The contactor comprises an electronic circuit for controlling the electric motor

[0028] - The moving area is extended by the parking area

[0029] - Each parking area includes a contact area

[0030] - the mechanism with a variable reduction coefficient is produced by a motion reducer, the last movable part of which is provided with a cam that cooperates with a direct drive integral with the carriage - the cam is provided with two cam profiles, one of which cooperates with a leg of the direct drive to drive the carriage in one direction of rotation of the movable part, and the other of which cooperates with a second leg of the direct drive to drive the carriage in the other direction of rotation of the movable part

[0031] the cam and each of the legs have complementary means for ensuring stops limiting the movement of the movable part in each direction of rotation

[0032] - the electronic circuit comprises a position sensor that measures the position of the carriage

[0033] - the position sensor is a two-state sensor consisting of two flexible conductive blades and means for measuring the resistance between said blades located on the electronic board, the two-state sensor switching between two states distinguished by measuring the resistivity between said blades and obtained for a given relative position between the bracket and the electronic board.

[0034] The invention also relates to an electromechanical electrical connection assembly provided with a housing containing the electric contactor according to claim 1 .

[0035] In a particular embodiment, the housing comprises an electronic board having means for controlling two electric contactors.

[0036] Optionally, the housing includes a second fixed contact and a second movable contact also driven by the electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention will now be described in more detail with reference to non-limiting exemplary embodiments specific to the foregoing advantages and considerations.A more particular description of the invention has been briefly given above.

[0038] [ Figure 1 ] Figure 1 shows a perspective view of an example of an electric contactor according to the present invention, with the cover removed and the housing partially broken away,

[0039] [ Figure 2 ] Figure 2 shows an exploded view of a first embodiment,

[0040] [ Figure 3 ] Figure 3 A view showing a cover of a first embodiment,

[0041] [ Figure 4 ] Figure 4 shows an axial view of the stator assembly molded into the housing and equipped with its electronic board,

[0042] [ Figure 5 ] Figure 5 shows a sectional view in a plane containing the axis of the gearbox of the first embodiment,

[0043] [ Figure 6 ] Figure 6 shows a cross-sectional view of a first embodiment, which is equipped with a direct push-pull drive and is shown at the end of the travel area,

[0044] [ Figure 7 ] Figure 7 shows a cross-sectional view of a first embodiment equipped with a direct push-pull drive and shown at the interface between the travel area and the contact area,

[0045] [ Figure 8 ] Figure 8 shows a cross-sectional view of a first embodiment equipped with a direct push-pull drive and shown at the end of the contact area,

[0046] [ Figure 9 ] Figure 9 A schematic diagram showing the angular position, angular velocity and force of the moving carriage throughout its travel,

[0047] [ Figure 10 ] Figure 10 shows a cross-sectional view of the second embodiment without the housing,

[0048] [ Figure 11 ] Figure 11 shows a perspective view of a variant embodiment of an electric contactor according to the invention, with the cover removed and the housing partially cut away,

[0049] [ Figure 12 ] Figure 12 shows an exploded view of the bracket and the movable part supported by the cam in the variant shown in the previous figure,

[0050] [ Figure 13 ] Figure 13 Shown Figure 11 Detailed view of the cam in the variant shown.

[0051] [ Figure 14 ] Figure 14 A sectional view of a variant embodiment is shown, which has a direct push-pull drive and is shown at the end of the movement area,

[0052] [ Figure 15 ] Figure 15A cross-sectional view of a variant embodiment is shown with a direct push-pull drive and at the interface of the movement area and the contact area,

[0053] [ Figure 16 ] Figure 16 A cross-sectional view of a variant embodiment is shown, which has a direct push-pull drive and is shown at the end of the contact area,

[0054] [ Figure 17 ] Figure 17 shows a partial sectional view of a variant embodiment with auxiliary contacts without a housing,

[0055] [ Figure 18 ] Figure 18 shows a detailed cross-sectional view of a variant embodiment shown in the previous figure,

[0056] [ Figure 19 ] Figure 19 shows a variant embodiment of the auxiliary contact,

[0057] [ Figure 20 ] Figure 20 A variant embodiment with two contactors in a single housing is shown,

[0058] [ Figure 21 ] Figure 21 A variant embodiment is shown with two contactors in a single housing sharing the same motor drive,

[0059] [ Figure 22 ] Figure 22 A variant embodiment is shown with two contactors in a single housing sharing the same motor drive and the same reduction gear.

[0060] [ Figure 23 ] Figure 23 A view is depicted of a variant embodiment of an electric contactor according to the invention, with the cover removed. DETAILED DESCRIPTION

[0061] Refer to the attached Figure 1 To the attached Figure 10The contactor described consists of a housing (700) made of electrically insulating material. The housing (700) has, on its inner surface, receiving areas (701, 702) for the shaft (111) of the rotor (110) of the electric motor (100) and the shaft (201) of the reduction stage of the gearbox (200). Another receiving area (703) is designed to receive the guide bearing of the pivot pin (410) of the bracket (400) supporting the movable contact part (500). The housing (700) with its receiving areas (701, 702, 703) is advantageously manufactured by molding a plastic material.

[0062] The housing (700) is closed by a cover plate (750) having on its inner surface shaft receiving areas (751, 752, 753) and stops limiting the travel of the cam (222). Advantageously, the stops are formed by pressing the cam (222) against the same fixed plane (760) of the cover plate (750), allowing 180° of travel between the two stops.

[0063] The connection terminal (601) is molded onto one side of the housing (700). In the exemplary embodiment described, the fixed contact (600) is a silver alloy pad (602) soldered to the inner surface of the connection terminal (601), or more generally a pad made of a material with good electrical conductivity. An electrical connection cable can be connected to the terminal (601) in a known manner.

[0064] The housing (700) also has an opening (710) for passing an electrical terminal (501) connected to a movable contact supported by the movable bracket (400). The second electrical terminal (501) is also designed for connecting an electric cable.

[0065] like Figure 2 and Figure 3 As shown, the motor (100) includes a stator (120) formed of a stack of sheets cut into three wound protrusions (121, 122, 123) radially extending from a peripheral yoke (125) and an unwound protrusion (124). The stator (120) including the coil (130) is held at the bottom of the housing (700) by an overmold (720).

[0066] In the depicted example, the stator (120) is asymmetrical, allowing it to be mounted on the housing (700) at an angle and freeing up space for mounting the gearbox (200).

[0067] The gear box (200) (in Figure 5The invention relates to a motor (particularly evident in FIG) comprising two reduction stages generated by the association of a rotor and two movable parts (210, 220): the first stage is driven by a pinion (112) coupled to a rotor (110) which is free to rotate relative to a fixed shaft (111).

[0068] The pinion (112) drives the gear (211) to form a first reduction stage. The gear (211) is coupled to the pinion (212) to form a first movable member (210), which drives a second gear (221) coupled to an eccentric protrusion forming a cam (222). The connection between the second gear (221) and the cam (222) forms a second movable member (220) guided by the rotor axis (111) offset from the center of the cam (222).

[0069] Typically, the reduction ratio between the rotor and the cam is 12:1, preferably between 4:1 and 30:1.

[0070] exist Figure 2 In the variant shown, in addition to the connection terminals (501, 601) that provide both electrical and mechanical connection to the application, the housing (700) and its cover (750) are also equipped with mounting lugs (705, 755) to secure the contactor to its application. However, considering the low weight of the actuator, the skilled person may consider removing the lugs (705, 755), leaving the connection terminals (501, 601) to bear all the mechanical stresses.

[0071] Electric motor control device (100)

[0072] The electric motor (100) is a permanent magnet motor controlled by an electronic circuit (800) integrated in the housing (100). The electronic circuit (800) comprises a conductive track which is connected to the ground pin of the housing connector (700) on the one hand and contacts the end of the spring (810) on the other hand. Figure 5 As shown, the spring passes through a hole made in the stator yoke of the motor. When the electronic circuit rests against the spring (810), it compresses the spring, and the coils of the spring deform laterally and come into contact with the inner surface of the hole, allowing the stator yoke to be at the same electrical potential as the ground pin of the connector.

[0073] Direct drive of a carriage (400) carrying a movable contact (500)

[0074] The gear motor has the function of controlling the movement of a carriage (400) carrying a movable contact piece (500) between a position in which the movable contact piece (500) is spaced apart from a fixed contact piece (600) and a position in which the movable contact piece (500) abuts against the fixed contact piece (600), wherein a first rapid movement is performed with low torque in a so-called approach area and then a movement is performed with low speed and high torque in a so-called contact area.

[0075] The aim is to ensure a short reaction time when the contactor is activated and, most importantly, to reduce the time that the contact parts are close enough to each other to strike an arc.

[0076] In the example described, this is accomplished by Figures 6 to 8 The direct push-pull drive devices shown in FIG are located at the end of the moving area, at the interface between the moving area and the contact area, and at the end of the contact area to achieve this.

[0077] The direct drive device (300) has an elliptical slot (310) defining a cam track in which the cam (222) engages to control constrained motion, thereby converting the rotational motion of the cam (222) into motion along an arcuate trajectory of a bracket (400) connected to the housing (700) by a pivot connection guided by a pin (410) inserted into receiving areas (703, 753) of the housing (700) and the cover (750). The entire assembly forms a disc-shaped cam with an internal profile.

[0078] The elliptical groove (310) has a shape determined by, for example, two straight line segments connected by an arc, the shape being a rectangular type with rounded corners, the side surfaces being generally semicircular, and the width of the groove being slightly larger than the diameter of the cam (222). When the cam (222) crosses the edge of the elliptical groove (310), it controls a motion having a continuously variable transmission ratio depending on the position of the cam (222) relative to the elliptical groove (310).

[0079] In the contactor version based on direct drive of the carriage by a drive, "direct drive" means that in all positions within manufacturing tolerances, the position of the carriage is directly and uniquely related to the angular position of the drive (a cam in the example described). In any position, the carriage has no free movement relative to the direct drive (300), except for the clearances created by manufacturing tolerances. This definition contrasts with drive arrangements in which the carriage has a motion phase, where the carriage is moved by means other than the carriage, such as a spring.

[0080] The movement of the bracket (400) is a rotation on an angular sector, thereby commanding the end supporting the movable contact (500) to follow an arc trajectory between the extreme position of the movable contact (500) farthest from the fixed contact (600) and the angular area where the surface of the movable contact (500) abuts against the surface of the fixed contact (600).

[0081] It should be noted that the movable bracket (400) can be rotatably guided by a pin (410) which is mounted in a fixed position relative to the bracket and is rotatably guided by the receiving area (703), but a person skilled in the art will be able to envision other solutions. For example, the guidance can be provided by a plastic protrusion on the movable bracket (400) which is directly inserted into the receiving areas (703, 753) of the housing (700) and the cover (750).

[0082] Movable contact (500)

[0083] Movable contact (500) (in Figure 2 The movable bracket (400) is supported by a movable bracket (400) via a thrust spring (450, 451), which is arranged between the rear surface of the movable contact (500) and the bracket (400) housing where the movable contact (500) is located.

[0084] The bracket (400) is composed of a guide member, the rear of which is guided by a pivot pin (410) inserted into the receiving area of ​​the housing (700). It is formed of a rigid insulator so as to exert a higher pressure on the front end containing the electrical contact (500). Its front part, opposite the pin (410), is extended by a lug (420) in which an oval slot (310) is cut, and the perforated end of this lug (420) forms the direct drive (300).

[0085] In one embodiment, the movable contact (500) is a flexible busbar (510).

[0086] The flexible busbar (510) may be formed from a laminate of copper foils welded together only at their ends, or from one or more braided layers of copper wire or similar electrical conductors, or from any other reversibly deformable electrically conductive connection.

[0087] The flexible busbar (510) is attached to the housing (700) to pass through an opening (710) directly above the rear of the bracket (400) to allow the bracket (400) to pivot without dragging the rear of the flexible busbar (510). The rear connection terminal (501) of the flexible busbar (510) has a hole (521) to accommodate a threaded insert for attaching a connection cable, which is in electrical contact with the upper portion of the connection terminal (501) at the rear of the flexible busbar (510).

[0088] The flexible busbar (510) has alternating bends (511, 512, 513) configured to allow the busbar to deform with substantially the same stress distribution between the upper and lower blades.

[0089] The movable contact (500) may be implemented in ways other than by a flexible busbar (510), such as by two conductive members connected together by a flexible connector.

[0090] The front contact region (530) of the movable contact (500) has an upper surface facing the lower surface of the fixed contact (600), so that when the bracket (400) is in the contact position, the contact region (530), preferably provided with a conductive pad (531), abuts in an overlapping manner against the lower surface of the fixed contact (600), which is also preferably provided with a conductive pad (602). The opposite surface abuts against the bracket surface (400) directly or via one or more thrust springs (450). Typically, after preloading, the travel of the spring (450) is a few millimeters, typically 1 mm to 4 mm.

[0091] A metal jumper (460) having two side tabs (461) folded from a sheet material to form a connecting top surface (463) is clamped onto the side of the front end of the bracket (400). The metal jumper closes the housing of the front contact area (530) of the movable contact (500) with the top surface (463), with an opening (464) cut to allow the pad (531) to pass through. The jumper (460) holds the front contact (530) in the front end of the bracket (400) under the pressure from the spring (450), which pushes it back to the top surface (463).

[0092] The bottom of the front end of the bracket (400) has one or more cavities (405) in which the rear ends of one or more springs (450) are engaged.

[0093] Kinematics

[0094] When the contactor is in the "off" position, the current flow between the two cables connected to the terminals (501, 601) is cut off, the bracket (400) is located at a position where its front end is farthest from the fixed contact (600), and there is an air gap between the pad (531) of the movable contact (500) and the pad (602) of the fixed contact (600).

[0095] Conversely, when the contactor is in the "closed" position, the bracket (400) is in a position where its front end presses the pad (531) of the movable contact (500) against the pad (602) of the fixed contact (600).

[0096] Figure 9 The kinematics of the contactor are illustrated, and more specifically

[0097] - the curve (50) shows the angular position of the mobile carriage (400) as a function of the angular position of the cam (222),

[0098] - curve (51) represents the evolution of the angular velocity of the mobile carriage (400) as a function of the angular position of the cam (222),

[0099] - Curve (52) shows the evolution of the force exerted by the movable contact (500) on the fixed contact (600) as a function of the angular position of the cam (222).

[0100] The pivoting of the moving bracket (400) first sweeps over the moving area and then sweeps over the contact area.

[0101] In the motion region (1), the cam (522) rotates the moving bracket (400) in an accelerated motion with low torque due to a low reduction ratio so as to reach a maximum speed when approaching the contact region.

[0102] The motion region (1) refers to a stroke during which the moving carriage (400) brings the movable contact (500) closer to the fixed contact (600) or moves them apart, but wherein the movable contact (500) and the fixed contact (600) are not yet in contact.

[0103] This moving area (1) may be preceded by a parking area (3) in which, in the absence of power from the electric motor (100), the force exerted on the moving carriage (400) irreversibly pulls it towards its rear stop.

[0104] The contact area (2) corresponds to the portion of the travel of the mobile carriage (400) that is covered after the contact surface (530) and, where applicable, the upper surface of the conductive pad (531) abuts against the lower surface of the fixed contact (600). In this contact area (2), the cam (522) continues to pivot the mobile carriage (400) with a higher torque than in the approach area to slow the movement, so as to compress the spring (450) and reach zero speed at the end of the contact area (2).

[0105] The contact area (2) may include a second parking area (4).

[0106] To close the contacts, the electric motor (100) is rotated, which drives the gearbox (200) and the drive device (300), causing the mobile bracket (400) to first pivot out of the parking area (3) located between the position Po of the bracket (400) in "open" abutment and the extreme point P1, and then enter the movement area (1), reaching point P2, at which point the upper surface of the conductive pad (531) abuts the lower surface of the fixed contact (600), thereby establishing electrical contact and mechanical contact.

[0107] The bracket (400) then continues to pivot in the contact area (2), first between points P2 and P3 where the contact force is greatest, and finally in the second parking area (4), until the cam (222) stops at point P4. Point P3 is also the limit point.

[0108] The parking areas (3, 4) are areas where the cam (222) is immobilized against the corresponding stopper when no power is supplied to the electric motor (100).

[0109] Double contact variant

[0110] exist Figure 10 In one variation shown, the contactor can control the opening and closing of two (or more) power contacts simultaneously or with a slight offset.

[0111] In this case, the housing is equipped with a single fixed contact having two contact pads welded to a conductor common to the two movable contacts, or equipped with two fixed contacts (600). The movable bracket (400) has two movable contacts (500) arranged in parallel.

[0112] For this purpose, one of the contacts has good arc resistance to arc discharge, but has low electrical conductivity and has a sacrificial pad.

[0113] The other contact has good electrical conductivity but less arc resistance and has a pad made of a material that is a good electrical conductor.

[0114] The first contact for ensuring arc resistance performance is closed first and opened last.

[0115] to this end, Figure 10 One of the embodiments shown is to provide a busbar (510) slotted at its end at the front contact (530) to form two parallel tongues (534, 533), one tongue supporting a sacrificial pad (532) and the other tongue supporting a good conducting pad (531).

[0116] The tongue (534) supporting the sacrificial pad (532) is preloaded by a spring (451) having a stiffness smaller than that of the spring (450) provided for the other tongue (533), so that the sacrificial pad (532) is closer to the sacrificial pad (603) on the surface of the fixed contact (600) than the good conductive pad (531) is closer to the good conductive pad (602) on the surface of the fixed contact (600), so as to ensure that the circuit is closed before the good conductive pads (531, 602) enter the arc discharge area in the moving area (1).

[0117] Direct drive variants

[0118] A variant embodiment of the direct drive device (300) is Figures 11 to 16 This embodiment is shown in Figure 1 、 Figures 2 to 6 、 Figure 7 、 Figure 8 The embodiment shown differs in that the oval slot (310) is open to form a "C" shape, which is achieved by extending the two legs (320, 330) of the body of the direct drive device (300). This embodiment also differs in that the cam (222) has two protrusions (223, 226) in the continuous axial extension of the movable part (220), as shown in FIG. Figure 12 and Figure 13 As shown, Figure 12 An exploded view of a movable member (220) and a carriage (400) is shown, the movable member cooperating with the carriage via a direct drive (300), and Figure 13 A detailed view of the movable part (220) is shown. Thus, the protrusions (223, 226) cooperate with each of the legs (320, 330), one of the protrusions (223, 226) ensuring the movement of the direct drive (300) during clockwise rotation of the cam (222), and the other during counterclockwise rotation.

[0119] Figures 14 to 16The diagram shows the successive stages of movement of the direct drive (300) when the contacts are closed by counterclockwise rotation of the cam (222). When the cam (222) rotates counterclockwise, the cam profile (224) of the protrusion (223) comes into contact with the leg (320) and causes the bracket (400) mechanically coupled to the direct drive (300) to rotate about its pin (410). Figure 14 Shows the state where the contacts are completely disconnected. Figure 15 shows the state corresponding to the electrical contacts between the pads (602, 531) of the fixed contact (600) and the movable contact (500), and Figure 16 The contact is shown in a fully closed state, where the force applied between the fixed contact (600) and the movable contact (500) is maximum in order to obtain the lowest possible contact resistance. This is achieved by having one side (228) of the protrusion (226) abut against the end (335) of the leg (330). Figure 16 Final closed position shown.

[0120] from Figure 16 Starting from the state shown, the contacts are opened by clockwise rotation of the cam (222). The cam profile (227) of the projection (226) then abuts against the leg (330) and causes the bracket (400) mechanically coupled to the direct drive (300) to rotate about its pin (410). This is achieved by abutting one end (225) of the projection (226) against one side (325) of the leg (320). Figure 14 Final disconnected position shown.

[0121] Although two different cam profiles (224, 227) are used to open and close the contacts, the movement of the carriage is always ensured by the cooperation of the cam (222) and the direct drive device (300). The use of two cam profiles (224, 227) advantageously makes it possible to benefit from a stroke of nearly 360° to ensure the opening or closing of the contacts, and thus obtain better displacement control in terms of manufacturing precision, as well as reduce the reduction factor required to obtain the same angular stroke of the carriage from the rotation of the movable part (220). As in the first embodiment, it is necessary to provide a high reduction ratio at the beginning and end of the stroke in order to obtain an irreversible equilibrium position without motor power and also to minimize the contact resistance in the closed position, but it is also necessary to maximize the opening and closing speeds in order to improve the actuator responsiveness and reduce arc discharge problems. To this end, the cam tracks (230, 240) are characterized by the evolution of their distances R1 and R2 from the axis of rotation (229) of the movable part (220), these cam tracks having: a first region (231, 241) in which the distances R1 and R2 start from a minimum and increase only slightly; followed by a second region (232, 242) in which the distances R1 and R2 increase rapidly; and followed by a final region (233, 243) in which the distances R1 and R2 are almost maximum and increase slightly to this maximum.

[0122] It can be noted that the cam tracks (230, 240) can only move the direct drive (300) when rotation of the movable member (222) causes the distance R1 or R2 of the contact point on the cam track (230, 240) between the protrusion (223, 226) and the associated leg (320, 330) to increase. In this way, one cam track (240) increases for clockwise rotation of the movable member (220), while the other cam track (230) increases for counterclockwise rotation of the movable member (220).

[0123] In the above example, the direct drive means (300) is provided by a cam. Of course, the means may be provided by equivalent means, such as a connecting rod, a toothed sector or a lever.

[0124] The following example describes the movement of a mobile carriage with a pivoting movement. Of course, the displacement can also be linear.

[0125] Variant with auxiliary contacts

[0126] The present invention also relates to a system for detecting a specific position of the opening or closing stroke of an electrical contact.For example, for safety reasons during processing, it must be ensured that there is galvanic isolation when the contactor is open and contact is made when the contactor is closed.

[0127] A possible means of detecting these positions is via a sensor arranged on the electronic board (800) which switches between two voltages when a position of the contactor travel is reached, i.e. the sensor is in a high state for a continuous part of the travel and in a low state for the rest of the travel.

[0128] The first implementation of this function is Figure 17 and Figure 18 As shown in, Figure 17 shows a perspective view of the electronic board (800), stator and bracket (400), and Figure 18 A side view of these elements is shown, with the stator additionally overmolded in the housing (700).

[0129] The detection device consists of two parallel blades (810, 820) attached to the electronic board (800) at one end and free at the other end. The free ends can each come into contact with a deformable blade (480, 490) attached to the bracket (400). The blades (810, 820, 480, 490) are electrically conductive and the complementary deformable blades (480, 490) attached to the bracket (400) are preferably electrically connected by cutting from the same sheet of conductive metal. The complementary deformable blades (480, 490) attached to the bracket (400) are also parallel and arranged in such a way that when the main contact is disconnected and the bracket is thus moved towards the electronic board, they simultaneously come into contact with the blades (810, 820) attached to the electronic board (800) at position Pc. Thus, in position Pc, the blades (810, 820) are in electrical contact via complementary deformable blades (480, 490) attached to the bracket (400). Position Pc can therefore be detected by measuring the resistivity between said blades (810, 820). To this end, the ends of the blades (810, 820) attached to the electronic board (800) can be electrically connected to appropriate components on the electronic board to perform this measurement.

[0130] The blades (810, 820) are "J" shaped, having two parallel legs (814, 816) separated by an angled portion (815). One of the legs (816) is shorter and has an end attached to the electronic board, and the other leg (814) is longer and terminates with a free end that contacts a complementary deformable blade (480, 490) attached to the bracket (400). In this way, the blades (810, 820) terminate with a press-fit connection for insertion into a circuit board on the side opposite the bracket (400). This enables the angled portion (815) of the blades to be directly overmolded into the housing (700), making it possible to control their positioning relative to the bracket (400) as much as possible. The electrical terminals of the stator coil (120) are also provided with crimp connectors extending towards the bracket (400), so that the stator and blades (810, 820) can be overmolded together in the housing (700) and the electronic board can be inserted into the overmolded assembly (720) in one operation to establish all electrical connections.

[0131] The blades (810, 820) are arranged at the edge of the electronic board (800), which is locally provided with a notch (850) to leave sufficient space for their overmolding. It should be noted that the overmolding of the stator (120) and the blades (810, 820) is by no means a limitation of this embodiment, the purpose being to correctly index these elements relative to the housing. It is also conceivable that the housing includes precise positioning elements and that the stator or blades are arranged, screwed or shrink-fitted therein.

[0132] The embodiment of providing a high state from position Pc of the open stroke is merely one specific example of an embodiment. It is easy to imagine a configuration in which the blades (810, 820, 480, 490) are arranged to provide a high value when reaching a position of the closed stroke, or even multiplying the number of sensors of this type to provide information about reaching multiple positions. The deformable blades can also have sufficient bending stroke to measure multiple positions during a single stroke (e.g., during the contact closing stroke). It is conceivable that one sensor is switched to a high state from the moment the conductive pads of the fixed contact and the movable contact make electrical contact, and that a second sensor is switched to a high state at the end of the stroke when the contact force is sufficient to minimize the resistance. Of course, in addition to the state of the sensor, its transition from one state to another is also of interest. Relevant positions to be measured include making electrical contact with the main contactor, the end-of-stroke positions of the open and closed strokes, reaching a sufficient distance between the fixed contact and the movable contact to ensure sufficient dielectric strength between these components at the operating voltage, and reaching a portion of the stroke with a high deceleration factor to potentially adapt to the control strategy for stopping.

[0133] Finally, the design shown suggests the use of rigid blades (810, 820) and complementary flexible blades (480, 490), but one skilled in the art can easily imagine variations in which the blades (810, 820) are flexible and contact the rigid metallized portion of the bracket. It is also conceivable that all blades (810, 820, 480, 490) are flexible. The basic premise is that the auxiliary contact must be flexible enough to provide a high state within the desired range of travel of the bracket (400) while avoiding damage.

[0134] Figure 19 A variation of the position detection system is shown in FIG, which shows a perspective view of a bracket (400) and flexible blades (810, 820) arranged on an electronic board (800), the electronic board being shown in a transparent manner. This design differs from the previous one in that the flexible blades (810, 820) are integrated into an SMD type component mounted on the electronic board (400). These flexible blades (810, 820) cooperate with a rigid metal insert (470) that is integral with the bracket (400) and is arranged as a whole to detect the position in the closing stroke.

[0135] This variation also has a second pair of flexible blades (830, 840) that cooperate with a second rigid metal insert (475) integral with the bracket (400), all arranged to detect position in the closed stroke.

[0136] The position detection is not limited to these examples, and the skilled person can easily envision other possible variants, such as the use of mechanical contactors arranged on the electronic board and having arms that cooperate with stops on the bracket, or the use of magnetic detection devices, such as Hall probes, which can be arranged on the electronic board to measure the field of a magnet arranged on the bracket or on one of the elements of the motion reducer assembly.

[0137] Position sensors can also be used to calibrate the travel of stepper motors. By using two sensors to detect the position of two stop points, it is known how many motor control steps there are between these two stop points. The position of the carriage between these two stop points can be determined by counting the number of steps taken from one stop point and knowing the evolution of the deceleration factor during the carriage travel.

[0138] The position sensor can also be used to detect during the opening stroke whether the process has been completed correctly and whether the movable contact has stuck to the fixed contact. Since the carriage is directly driven by the motor, if the normal opening process fails to lift the movable contact from the fixed contact, the contact opening can be forced by increasing the motor supply current.

[0139] Variant for closing multiple contacts

[0140] The present invention also relates to electric contactors for closing a plurality of different circuits in various configurations, some of which are configured in Figure 20 、 Figure 21 and Figure 22 Therefore, it is proposed to combine components of greater or lesser proportions to close multiple circuits in order to meet different needs. In particular, Figure 20 The invention illustrates an arrangement of two contactors located in the same housing (700) and sharing common electronics (800). These electronics independently control the windings of the stators (120) of two motors, which drive two gearboxes (200) which move two carriages (400) to close two independent circuits. The advantage of this solution is that it provides completely independent control of the closing of the two circuits while integrating a maximum number of components.

[0141] This independence of contact closure is not always necessary, and in some cases it is useful to provide a joint closure of the circuit, either synchronously or asynchronously. Figure 21 A dual-contact variant is illustrated, in which the housing (700), the electronic board (800), and the rotor (110) and stator (120) forming the electric motor are shared. Thus, the rotor (110) drives two sets of gearboxes (200), each of which moves a carriage (400) to close two different contacts. This configuration is advantageous for proposing different asynchronous closing strategies. For example, by selecting different cam profiles for the direct drive (300) of each carriage (400), it is possible to close or open the first contact and then the second contact.

[0142] The requirements may be multiple, for example, it may be desirable to start the movement of each carriage (400) at different times so that the torque peaks associated with starting each motor are asynchronous. This can be achieved by having one of the cams have a constant radius at the start of formation to avoid generating movement. Asynchronous closing can also be used to pause electric motor control after one of the circuits has been opened or closed before starting or continuing the closing or opening sequence of the second circuit.

[0143] Finally, it is also possible to disconnect the two circuits independently, confining the movement of each of the carriages (400) to an angular sector of the rotation of the module (220). For example, the cam (222) can be specifically shaped to drive the associated direct drive (300) only through an angle of less than 180° over the entire stroke. We can then imagine several situations and adapted cam profiles, for example, to continuously close the two contacts while driving the motor in the same direction, thereby generating several states, one in which both contacts are open, another in which one contact is open and the other is closed, and a final state in which both contacts are closed. Another possibility is to generate a cam profile that closes the associated contacts for rotation in opposite directions. Then, over the entire rotational stroke, there will be an intermediate position in which both contacts are open, and from this position, rotation in one direction will close only one contact, and rotation in the other direction will close only the other contact.

[0144] at last, Figure 22 Shown is a collection of all components except the fixed contact (630) and the movable contact (500). Figure 10 In contrast to the embodiment shown, this configuration enables the closing of two circuits which can be independent of each other but originate from the same control command. The circuits can also be closed synchronously or asynchronously by selecting different distances between the fixed and movable contacts for the two circuits.

[0145] Direct drive variants

[0146] Figure 23 A variation of the direct drive device (300) is shown in FIG. This embodiment differs from the previous embodiment in that the direct drive device (300) is a connecting rod fixed with one degree of rotational freedom, one end of which is fixed to the last movable part (220) eccentrically relative to the rotation axis of the movable part (220), and the other end is fixed to the bracket (400) to provide a variable reduction ratio between the motor (100) and the bracket (400).

Claims

1. An electric contactor, comprising a fixed contact piece (600) and a movable contact piece (500) driven by a bracket (400), and an electric motor (100), wherein the electric motor controls the movable contact piece (500) to reversibly move between a maximum approach position P2 and a disconnection position P1; in the maximum approach position, mechanical and electrical contact is established with the fixed contact piece (600); In the disconnected position, the contact members (500, 600) are spaced furthest apart from each other, and their travel comprises: a moving region (1) in which the movable contact member and the fixed contact member (500, 600) are spaced apart from each other; and a contact region (2) in which the conductive surface of the movable contact member (500) is pressed against the conductive surface of the fixed contact member (600), characterized in that the electric motor (100) drives a mechanism whose reduction coefficient varies with position, There is a deceleration coefficient C at the interface between the moving area (1) and the contact area (2) of the contact member (500, 600) I , the deceleration coefficient C I Lower than the deceleration coefficient C at the end of the movement area (1) and the contact area (2) I1 and C I2 .

2. The electric contactor according to claim 1, characterized in that: The electric motor (100) is connected to the bracket (400) supporting the movable contact (500) via a direct push-pull drive (300).

3. The electric contactor according to claim 1, characterized in that The movable contact (500) is composed of the end of a conductive flexible busbar (510).

4. The electric contactor according to claim 3, characterized in that: The movable contact (500) is moved by a bracket (400) having a rotational motion, one end of the bracket (400) being connected to the movable contact (500) and being hinged relative to a pivot (410) located at the other end thereof, the flexible busbar (510) having a second end attached to the contactor housing (700) to form an electrical connection terminal (501), and wherein the position-dependent reduction coefficient mechanism is coupled to the movable bracket (500).

5. The electric contactor according to claim 1, characterized in that: The movable contact member (500) is moved by a bracket (400) driven by a connecting rod.

6. Electric contactor according to the preceding claim, characterized in that The connecting rod is fixed with one degree of rotational freedom to provide a variable reduction ratio between the motor (100) and the bracket (400).

7. The electric contactor according to claim 1, characterized in that The movable contact piece (500) supports a conductive pad (531), which cooperates with a conductive pad (602) supported by the fixed contact piece (600).

8. The electric contactor according to claim 1, characterized in that: The movable contact piece (500) is provided with two tongue-shaped portions (533, 534), and the two tongue-shaped portions respectively support a conductive pad (531) and a sacrificial pad (532).

9. The electric contactor according to claim 1, characterized in that: The electric contactor comprises an electronic circuit (800) for controlling the electric motor (100).

10. The electric contactor according to claim 1, characterized in that The movement area (1) is extended by a parking area (3).

11. The electric contactor according to claim 1, characterized in that: The contact area (2) includes a parking area (4).

12. The electric contactor according to claim 1, characterized in that The mechanism with a variable reduction coefficient is produced by a motion reducer (200), the last movable part (220) of which is provided with a cam (222) cooperating with a direct drive (300) integral with the carriage (400).

13. Electric contactor according to the preceding claim, characterized in that The cam (222) is provided with two cam profiles (224, 227), wherein the cam profile (224) cooperates with a leg (320) of the direct drive device (300) to drive the bracket in one rotation direction of the movable part (220), and the cam profile (227) cooperates with a second leg (330) of the direct drive device (300) to drive the bracket in another rotation direction of the movable part (220).

14. Electric contactor according to the preceding claim, characterized in that The cam (222) and each of the legs (320, 330) have complementary means for ensuring stops that limit the travel of the movable part (220) in each direction of rotation.

15. The electric contactor according to claim 9, characterized in that The electronic circuit (800) includes a position sensor that measures the position of the bracket (400).

16. Electric contactor according to the preceding claim, characterized in that The position sensor is a two-state sensor consisting of two flexible conductive blades (810, 820, 480, 490) and a device for measuring the resistance between the blades located on the electronic board (800), the two-state sensor switching between two states, the two states being distinguished by measuring the resistivity between the blades, and the two states being obtained for a given relative position between the bracket (400) and the electronic board (800).

17. An electromechanical electrical connection assembly having a housing (700) containing the electric contactor according to claim 1.

18. Electromechanical electrical connection assembly according to the preceding claim, characterized in that The housing contains a second electric contactor according to claim 1 , the housing comprising an electronic board having means for controlling the two electric contactors.

19. The electromechanical electrical connection assembly according to claim 17, wherein: The housing (700) includes a second fixed contact piece (600) and a second movable contact piece (500) also driven by the electric motor (100).

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