Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H39/006—Opening by severing a conductor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
  • H01H2009/305—Means for extinguishing or preventing arc between current-carrying parts including means for screening for arc gases as protection of mechanism against hot arc gases or for keeping arc gases in the arc chamber
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H2039/008—Switching devices actuated by an explosion produced within the device and initiated by an electric current using the switch for a battery cutoff
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
  • H01H9/34—Stationary parts for restricting or subdividing the arc, e.g. barrier plate
  • H01H9/342—Venting arrangements for arc chutes

Definitions

• the present invention relates to the general field of electrical cut-off devices, and more particularly those of the pyrotechnically actuated type.
• Pyrotechnic cut-off devices comprising a body in which is present a pyrotechnic initiator configured to, when triggered, set in motion a piston provided with a relief in the direction of a conductive bar to be cut.
• the document filed under the number FR1908466 which describes a pyrotechnic cut-off device is known.
• the device presented in the document FR1908466 makes it possible to obtain satisfactory results, in particular for voltages of intensities ranging up to 18 kA and under voltages of the order of 1 kV.
• the Applicant has noticed that the general performance of the device is limited by the level of electrical insulation obtained after the electrical cut.
• the object of the invention is to provide a cut-off device which ensures more reliable and complete electrical insulation, that is to say making it possible to maintain a complete cut-off of the current in a given time which remains short, and a maintenance of a high level of electrical insulation after activation of the cut-off device, the high level of insulation being demonstrated by a leakage current of the order of 10 mA for voltages of the order of 2.5 kV, and /or an electrical insulation resistance greater than 80 MOhm.
• the invention proposes a cut-off device comprising: a conductive element and a movable piston, the piston being capable of moving between a first position for the passage of current in the conductive element and a second current cut-off position , the piston being configured to break the conductive element during its passage from its first position to its second position, the piston being positioned in a cavity for receiving a reception when said piston is in its second position, the reception cavity being delimited by at least one internal wall of the reception element, the internal wall being made of electrically insulating material.
• the receiving element comprises fins made of electrically insulating material and extending inside the receiving cavity projecting from said at least one internal wall of the receiving element.
• the addition of the fins in the cavity makes it possible first of all to increase the effective surface of insulating material making it possible to dissipate the energy of the plasma generated following the cutting of the conductive element by the piston, in particular with respect to a cylindrical receiving cavity with no inwardly projecting portion.
• the reception cavity forms a sealed enclosure inside which the plasma of the electric arc is dissipated thanks to the total surface of insulating material within the reception cavity.
• the various elements made of insulating material form energy exchange surfaces allowing the large quantity of energy contained in the electric arc to be dissipated.
• an electric arc is produced for a short time.
• the plasma from the electric arc then deposits soot on the walls of the receiving cavity.
• the conductive element is cut into two sections coupled to the rest of the circuit and not electrically connected to each other. These two sections are separated from each other by a distance which depends on the diameter of the piston and the width of the bar in the case where the piston is circular.
• the soot deposited on the walls of the receiving cavity can form non-insulating paths which could restore the passage of current between the two sections of the conductive element.
• the presence of the fins in the cavity makes it possible to increase the length of the soot path between the two sections of the severed conductive element and thus to reduce the risk of resumption of an electric current.
• the device preferably comprises at least six fins to maximize the path to be traveled by the soot and to maximize the material making it possible to dissipate the energy of the plasma created during the cutting while minimizing the mass of the cut-off device.
• the fins may comprise a first end secured to said at least one internal wall of the receiving element and a second end which is free inside the receiving cavity, the fins having all the same length between their first end and their second end to maximize the number of fins that can be accommodated in the receiving cavity while maintaining sufficient distance between the fins.
• the fins may comprise a first end secured to said at least one internal wall of the receiving element and a second end which is free inside the receiving cavity, the device comprising first fins having a first length between their first end and their second end, and second fins having a second length between their first end and their second end, the second length being less than the first length, each first fin being disposed between two second fins and each second fin being disposed between two first fins.
• the receiving element may further comprise at least one additional cavity separate from the receiving cavity and connected to said receiving cavity by at least one channel, said at least one channel being open when rupture of the conductive element by the piston.
• Such a cut-off device comprising at least one additional cavity makes it possible to evacuate the plasma generated when the conductive element breaks towards the additional cavity, thus limiting the quantity of plasma in the receiving cavity which tends to slow down the piston and to ensure electrical continuity between the broken ends of the conductive element.
• the at least one channel can be closed off by the piston when said piston is in its second position.
• the at least one channel can be located in line with a breaking point of the conductive element.
• the receiving element may comprise at least two separate additional cavities each connected to the receiving cavity by at least one channel.
• each additional cavity can be connected to the receiving cavity by at least one channel located in line with a breaking point of the conductive element, at least one channel being located in line with each breaking point of the conductive element.
• said at least one additional cavity may comprise a length at least equal to half the length of the receiving cavity.
• the volume of said at least one additional cavity may be greater than or equal to the volume of the receiving cavity.
• said at least one channel can open into the receiving cavity on a portion of said receiving cavity having a conical surface of complementary shape to a portion of the piston.
• the device is a pyrotechnic breaking device comprising a pyrotechnic initiator, the piston being able to move following the actuation of the pyrotechnic initiator between its first position and its second position.
• the conductive element can be configured to be broken by the piston at two breaking points.
• the conductive element is configured to be broken at a breaking point and bent by the plunger.
• a secure electrical installation comprising a cut-off device according to any one of the possible characteristics and an electrical circuit connected to the conductive element of said device.
• a vehicle comprising a secure electrical installation according to one of the possible characteristics.
• Figure 1 is a schematic representation of a sectional view of a cut-off device according to a first embodiment of the invention, the piston being in the first position.
• Figure 2 is a schematic representation of a sectional view of the cutting device of Figure 1 in which the piston is in the second position.
• Figure 3 is a partial perspective view of the receiving element of the switching device of Figure 1.
• Figure 4 is a perspective view of a receiving element of the cut-off device according to a second possible embodiment of the invention.
• Figure 5 is a schematic representation of a secure electrical circuit in which there is a cut-off device according to the invention.
• a breaking device 100 comprises a body 10 inside which are installed a pyrotechnic initiator 20, a piston 30, and a conductive element 40.
• the piston 30 is mounted so as to be movable between a first storage position, illustrated in FIG. 1, and a second breaking position, illustrated in FIG. 30 being moved from its first position to its second position by the actuation of the pyrotechnic initiator 20.
• the function of the piston 30 is to break the conductive element 40 during its passage from its first position to its second position, thus cutting the flow of electric current through the conductive element 40.
• the device 100 comprises a first 41 and a second 42 electrical terminals intended to be connected to an electrical circuit to be cut and which correspond here to two ends of the conductive element 40.
• the conductive element 40 here takes the form of a bar or electrically conductive tab.
• the device 100 can comprise a plurality of elements drivers. An example of installation comprising an electrical circuit connected to terminals 41 and 42 will be described in connection with figure 4.
• the conductive element 40 comprises at least one zone of weakness 43 which is intended to form a point of rupture of the conductive element 40.
• the conductive element 40 comprises two areas of weakness 43, thus making it possible to ensure a breakage of the conductive element 40 at two points of rupture and to detach a sacrificial portion 44 from the rest of the conductive element 40 .
• the body 10 may have a cylindrical shape with a main axis Z, as shown in the figures, other shapes are however possible.
• the body 10 is formed by a storage element 11 and a receiving element 12 which are assembled together.
• the storage element 11 has a storage cavity 11a in which the piston 30 is located when the piston 30 is in its first position.
• the receiving element 12 has a receiving cavity 12a which is aligned with the storage cavity 11a and which communicates with said storage cavity 11a.
• the reception cavity 12a is delimited by an internal wall 120 forming an enclosure.
• the reception cavity 12a is intended to receive the piston 30 when said piston 30 is in its second position, as illustrated in FIG. 2.
• the storage cavity 11a and the reception cavity 12a form a housing in which can be move the piston 30 and which is traversed by the conductive portion 44 of the conductive element 40.
• the pyrotechnic initiator 20 comprises a pyrotechnic charge connected to connectors 21 .
• the pyrotechnic charge is, when it is initiated for example using a current passing through the connectors 21, able to generate a pressurizing gas by its combustion.
• the conductive elements 21 can be connected to a control device C (FIG. 4) configured to actuate the pyrotechnic initiator 20 when an anomaly is detected.
• the piston 30 has, in the embodiment illustrated in Figures 1 and 2, a form of revolution around the axis Z.
• the axis Z corresponds to the axis of movement of the piston 30 and defines an axial direction D z .
• the piston 30 comprises a circumferential groove in which a seal 31, for example an O-ring, is housed.
• the piston 30 can move in a direction of movement along the Z axis inside the body 10 between a high position (first position) as in Figure 1, and a low position (second position) as in the FIG. 2. As long as the pyrotechnic initiator 20 has not been triggered, the piston 30 is in its first position.
• the receiving element 12 of the body 10 of the switching device 100 comprises, in the bottom of the receiving cavity 12a, projecting portions 60 extending inside the receiving cavity 12a.
• the projecting portions 60 form fins.
• These fins 60 comprise, in a radial direction DR orthogonal to the axial direction D z , a first end 61 secured to the internal wall 120 and a second end 62 free.
• the fins 60 thus extend, in the radial direction DR, from the internal wall 120 of the receiving element 12 towards the main axis Z.
• the fins 60 comprise a first side 63 integral with a bottom wall 122 of the receiving cavity 12a and a second free side 64 intended to face the piston 30 when the receiving element 12 is assembled with the storage element 11 .
• the receiving element 12 further comprises a tip 65 projecting in the axial direction D z from the bottom wall 122 of the receiving cavity 12a towards the conductive element 40.
• the tip 65 is extends in the axial direction D z over the entire height of the cavity 12a to rest against an underside of the conductive element 40 when the receiving element 12 is assembled with the rest of the cut-off device 100 and the piston 30 is in its first position.
• the fins 60 extend to the maximum, in the radial direction DR, up to the tip 65.
• the piston 30 further comprises on its lower part intended to come into contact with the conductive element 40, a central part hollowed out in the axial direction D z .
• the piston 30 breaks the conductive element 40 at the level of the two zones of weakness 43, and the broken portion 44, bends around the tip 65, as illustrated in Figure 2, the piston 30 stopping in contact with the second side 64 of the fins 60 of the receiving element 12.
• the fins 60 in the receiving cavity 12a make it possible to increase the effective surface area of insulating material able to dissipate the energy of the plasma generated when the conductive element 40 is cut by the piston 30.
• the fins 60 make it possible to increase the length of the soot path between the two cut sections of the cut conductive element 40 and thus to reduce the risk of resumption of an electric current at the end of the actuation of the breaking device 100.
• the fins 60 are preferably made of plastic material and may extend along the axial direction D z only over a portion of the height of the reception cavity 12a.
• FIG 4 is shown schematically a perspective view of a receiving element of a switching device according to a second embodiment.
• the second embodiment illustrated in Figure 4 differs from the first embodiment illustrated in Figures 1 to 3 in that, on the one hand, the receiving element 12 does not include a tip 65, and, on the other hand, in that the receiving element 12 comprises additional cavities 50 located around the receiving cavity 12a and which are placed in communication with said receiving cavity 12a by channels 51 .
• the plurality of additional cavities 50 thus makes it possible to improve the insulation of the plasma pockets.
• the receiving element 12 may not include any additional cavity.
• the additional cavities 50 are distinct cavities from the receiving cavity 12a, in particular the piston 30 does not enter the additional cavities 50 when said piston 30 is positioned in the receiving cavity 12a.
• the channels 51 which connect the additional cavities 50 to the receiving cavity 12a are open when the piston 30 breaks the conductive element 40, and are closed off by the piston 30 when the said piston 30 is in its second position.
• Such additional cavities 50 make it possible to receive the plasma generated when the conductive element 40 breaks, the plasma thus being evacuated from the reception cavity 12a towards the additional cavity(ies) 50 via the channel(s) 51 .
• the Applicant has in fact realized that the fact that the plasma stagnates in the receiving cavity 12a tends on the one hand to slow down the movement of the piston 30, and on the other hand tends to allow the flow of electric current despite the rupture of the conductive element 40.
• the fact of moving the plasma out of the cavity reception 12a thus allows the device 100 to more quickly and more effectively cut the flow of an electric current between the two terminals 41 and 42 of the conductive element, 40 and this despite the fact that the voltage and the intensity of the current electricity is high (in particular a voltage greater than 500V and an intensity greater than 10kA) and cause the generation of plasma when the conductive element 40 breaks.
• the piston 30 can then close the channel or channels 51, thus maintaining the plasma in the additional cavities 50, which thus limits the risk that the current continues to flow despite the cutoff of the conductive element 40.
• the channels 51 are located at the level of the face of the receiving element 12 intended to be in contact with the conductive element 40, in other words, in line with a breaking point of the conductive element 40. This allows better evacuation of the plasma towards the additional cavity or cavities 50. Indeed, the plasma is generated at the breaking point of the conductive element 40.
• the channels 51 can be located close to a breaking point of the conductive element 40, that is to say at a distance less than or equal to 5 mm from a breaking point of the conductive element 40.
• the size of the additional cavity or cavities 50 is advantageously large enough in relation to the size of the reception cavity 12a.
• the additional cavity or cavities 50 have a length which is at least equal to the length of the reception cavity 12a.
• the total volume of the additional cavity or cavities 50 is greater than or equal to the volume of the reception cavity 12a.
• the total volume of the additional cavity or cavities 50 is greater than the volume of the reception cavity 12a.
• the channels 51 open into the receiving cavity 12a on a portion of said receiving cavity 12a which has a conical surface.
• the shape of the conical surface of the portion of the reception cavity 12a is complementary to the shape of a portion of the piston 30, thus making it possible to improve the sealing of the closure of the channels 51 by the piston 30.
• the channels 51 can be located in a lower part of the reception cavity 12a.
• FIG. 5 schematically shows an example of a secure electrical installation 300 implementing the cut-off device 100 according to the invention.
• the secure electrical installation 300 comprises a secure power supply system 310 comprising the cut-off device 100 (represented very schematically) and a power supply circuit 311 .
• the supply circuit 311 here comprises an electric generator G connected to the second terminal 42 of the conductive portion 40 of the cut-off device 100.
• the electric generator G can for example be a battery or an alternator.
• the secure power system 310 further comprises a control element C configured to actuate the pyrotechnic initiator 20 when an anomaly is detected.
• the control element C is connected to the pyrotechnic initiator 20 via the connectors 21.
• the anomaly in response to which the control element C can trigger the pyrotechnic initiator 20 can be an electrical anomaly, such as a current threshold overrun in the circuit, or a non-electrical anomaly such as the detection of a shock. , for example a sudden deceleration of the control element, a change in temperature, pressure, etc.
• the control element C is capable of sending an electric current to the pyrotechnic initiator 20 for its triggering in order to cut off the current, as described previously.
• the secure electrical installation 300 finally comprises an electrical device D connected here to the first terminal 41 of the conductive portion 40 of the cut-off device 100 to be powered by the secure power supply system 310.
• a motor vehicle may include a secure electrical installation 300.

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• Fuses (AREA)
• Circuit Breakers (AREA)
• Switch Cases, Indication, And Locking (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=74871545

Family Applications (1)

Country Status (6)

Family Cites Families (13)

• 2020
  • 2020-12-10 FR FR2013018A patent/FR3117665B1/fr active Active
• 2021
  • 2021-12-03 US US18/256,828 patent/US20230395344A1/en not_active Abandoned
  • 2021-12-03 CN CN202180083496.1A patent/CN116601735A/zh active Pending
  • 2021-12-03 JP JP2023535354A patent/JP2023548629A/ja not_active Ceased
  • 2021-12-03 EP EP21840651.0A patent/EP4260354A1/de active Pending
  • 2021-12-03 WO PCT/FR2021/052210 patent/WO2022123159A1/fr active Application Filing

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