Cut-off device for an electric current, battery module comprising such a device and motor vehicle provided with such a module

Abstract

A circuit breaker for an electric current, said device comprising a movable member (2) provided with an electrical conductor (4), said device being configured to move said movable member (2) between a first position, referred to as armed, allowing current to flow in the conductor (4), and a second position, referred to as disarmed, interrupting said current flow, said device further comprising an actuator (12), configured to trigger a transition of the movable member (2) from the armed position to the disarmed position in the event of a fault on an electrical circuit in which said device is integrated, said device further comprising a reset member (36) having a manual actuation zone (38), configured to move the movable member (2) from the disarmed position to the armed position, thereby also triggering a reset of the actuator (12), said actuation zone (38) forming a visual indicator of a disarmed state of said device.

Description

[0001] The invention relates to a current-cutting device for an electric current, a battery module comprising such a device, and a motor vehicle equipped with such a module. It will find particular application in the case of charging or discharging currents of high-voltage batteries supplying an electric machine used to drive said vehicle, especially with direct current.

[0002] In this field, it is known to open a power circuit used for charging and discharging a battery using manual disconnect devices. These devices ensure that the current no longer flows, particularly during emergency response to an accident. Their limitation is that they do not trip automatically. It is also known, for example from EP2538429, for disconnect devices that open the circuit in case of shocks, but once activated, they require access to the battery modules in which they are installed for replacement. Another drawback is that they do not provide visual indicators of their activation, which is necessary to verify that the current flow has been interrupted. Document FR 788 639 A describes a disconnect device for an electric current according to the preamble of claim 1.

[0003] The invention aims to overcome, at least in part, the aforementioned drawbacks and to this end proposes a circuit breaker for an electric current, in particular direct current, according to claim 1, said device comprising, among other things, a movable member provided with an electrical conductor, said device being configured to allow passage of said movable member between a first position, said armed, allowing current to flow in the conductor, and a second position, said disarmed, preventing said current from flowing, said device further comprising an actuator, configured to trigger the passage of the movable member from the armed position to the disarmed position in the event of a fault on an electrical circuit in which said device is integrated, said device further comprising a reset member having a manual actuation zone,configured to move the moving part from the disarmed position to the armed position and to further trigger a re-arming of the actuator, said actuation zone forming a visual indicator of a disarmed state of said device.

[0004] Thanks to the moving part and the actuator, the device according to the invention is automatically triggered. Furthermore, the user receives confirmation of successful triggering via the visual indicator on the reset mechanism. Since this reset mechanism is also manually operated and capable of re-engaging the actuator via the moving part, the device can be easily reset from the outside.

[0005] According to the invention, the device also includes a chamber allowing compression of a fluid during the transition from the disarmed position to the armed position, under the effect of the movement of said moving member, said device further including at least one channel connecting a zone, called the blowing zone, to said compression chamber so as to direct a flow of said fluid towards said blowing zone to cut an electric arc forming during the transition from the armed position to the disarmed position.

[0006] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: The device is configured to allow movement between the armed and disarmed positions of the moving part and / or the resetting part by translation along a displacement axis. The device is configured so that the translation of the resetting part causes the translation of the moving part. The resetting part includes a handle. The actuator is configured to re-arm itself upon translation of the moving part. The device includes a housing defining a recess for the moving part. The recess also houses the actuator. The housing provides a passage for the resetting part so that the resetting part can be operated by a user in the disarmed position. The device is configured so that the resetting part is flush with the housing in the armed position. The device includes two fixed terminals for connecting to the circuit.said device further comprises a fixed conductive bar, said device is configured such that said conductor is in contact, on the one hand, with a first of said connection terminals and a first connection point of said bar and, on the other hand, with a second of said connection terminals and a second connection point of said bar, in the armed position, said conductor comprises at least one ring, said ring is split so as to exhibit radial elasticity, said rings are two in number, said device is configured such that a first of said rings establishes a current flow between said first connection terminal and said first connection point of the bar and that a second of said rings establishes a current flow between said second connection terminal and said second connection point of the bar, in the armed position, said fluid is air,said channel and / or said chamber are formed in said casing, said chamber is traversed by said resetting device, said conductor includes an arc initiation zone, said arc initiation zone is located near an outlet end of said channel, in the armed position, said arc initiation zone is located at the level of the first and second rings furthest from said chamber.

[0007] The invention also relates to a battery module comprising the cut-off device described above.

[0008] The said module preferably includes at least one high-voltage battery for supplying electrical current to an electric machine used to drive a motor vehicle.

[0009] The invention also relates to a vehicle, in particular a motor vehicle, comprising such a battery module.

[0010] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description which follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which: [ Fig 1 ] illustrates schematically, according to an axial cross-section, a first device in an armed position; [ Fig 2 ] illustrates schematically, according to an axial cross-section, the device of the figure 1 , in a disarmed position; [ Fig 3 [ ], schematically illustrates, along an axial cross-section, an example of a device according to the invention, in a disarmed position

[0011] The invention relates to a switching device for direct current. Such a device is intended, in particular, for interrupting the charging and / or discharging current of a high-voltage battery supplying an electric machine used to drive a motor vehicle. "High voltage" is understood to mean an electrical voltage greater than 100 V, for example, approximately 400 V.

[0012] As illustrated in figures 1 et 2 The device comprises a movable member 2, provided with an electrical conductor 4. The movable member 2 here includes an armature 3 carrying the electrical conductor 4. The conductor 4 advantageously comprises at least one ring 9, 9'. The ring 9, 9' is advantageously split so as to exhibit radial elasticity for good contact with the other conductive members.

[0013] The said device is configured to move the said movable part 2 between a first position, called armed, allowing current to flow in the said conductor 4, along a line shown in dotted lines in the figure 1 and a second position, called the disarmed position, cutting off the current flow. The disarmed position is illustrated in the figure 2 in which we observe that the flow of current has been interrupted by the movement of conductor 4.

[0014] The device herein comprises a housing 6 defining a compartment 8 for the movable part 2. The housing 6 may, for example, have a cylindrical and / or parallelepiped shape. The device includes two fixed connection terminals 7, 7' for the circuit. These connection terminals 7, 7' are located, for example, on the housing 6.

[0015] Preferably, said device is configured for a passage of the movable part 2 between the armed position and the disarmed position by a translation along a displacement axis 10. Said displacement axis 10 corresponds here to a longitudinal extension axis of the housing 6. In the illustrated embodiment, the movable part 2 is moved from left to right during the passage from the armed position to the disarmed position.

[0016] The device further includes an actuator 12, configured to trigger a transition of the moving part 2 from the armed position to the disarmed position in the event of a fault in an electrical circuit in which the device is integrated. The activation of the device according to the invention is thus automatic. Preferably, the housing 8 also accommodates the actuator 12.

[0017] By way of non-limiting example, according to a first variant, the actuator 12 comprises a fault current detector 14 and a spring element 16. The device is configured such that the fault current detector 14 maintains the spring element 16 in a compressed state as long as no fault current is detected and releases the spring element 16 in the opposite case. Once released, the spring element 16 extends and causes the moving part 2 to move from the armed position to the disarmed position.

[0018] The fault current detector comprises, for example, an electromagnet 18 connected to a drive shaft 22. The drive shaft 22 is rotatable about the axis of movement 10. The elastic element 16 comprises a spring 28 and a movable support 30. The spring 28 comprises a plurality of coils. One 32 of the coils, referred to as the first end coil, is connected to a first end of the movable support 30. The first coil 32 is also in contact with the movable element 2. Another 34 of the coils, referred to as the second end coil, is in contact with a body 24 of the housing 6, in the armed position. Said mobile support 30 includes at a second end, opposite its first end, a rod 20, retained in a groove 26 of the body 24 in the armed position, which keeps the spring 28 compressed between the body 24 and the mobile member 2.

[0019] In the event of a fault current occurring, the drive shaft 22 is rotated by said electromagnet 18 and dislodges the rod 20 from the groove 26. Said spring 28 and said movable support 30 are then free and the spring 28 relaxes, moving said movable body 2 from the armed position to the disarmed position.

[0020] The device further comprises a resetting mechanism 36. This resetting mechanism has a manual actuation zone 38, configured to move the movable part 2 from the disarmed position to the armed position, thereby also resetting the actuator 12. This actuation zone 38 also serves as a visual indicator of the disarmed state of the device. Thanks to this actuation zone 38, the user can thus externally reset the device and receive feedback confirming successful activation.

[0021] The housing 6 here provides a passage 40 for the resetting mechanism 36, so that the resetting mechanism 36 can be operated by a user in the disarmed position. The resetting mechanism 36 includes, for example, a handle forming the manual actuation zone 38. The handle extends, for example, along the axis of movement 10. The actuator 12 and the handle of the resetting mechanism 36 are arranged on either side of the movable part 2, along the axis of movement 10.

[0022] In the illustrated embodiment, the user performs a reset by moving the handle of the reset mechanism 36 from right to left. The moving part 2 then returns to the cocked position and the spring 38 is compressed again while the rod 20 of the movable support 30 is housed in the groove 26. The current flow 5 can thus resume, as in the figure 1 In the same figure, it can be seen that the said device is configured so that the said cocking member 36 is flush with the said housing 6 in the cocked position. In other words, the cocking member 36 is only visible from a longitudinal end 42 of the said handle and cannot be operated from the outside.

[0023] The said resetting member 36 is preferably movable in translation along the said axis of movement 10. The said device is configured so that the translation of the resetting member 36 causes the translation of the movable member 2 from the disarmed position to the armed position and / or so that the translation of the movable member 2 causes the translation of the resetting member 36 from the armed position to the disarmed position. The said actuator 12 is configured to re-arm itself under the effect of the translation of the said movable member 2.

[0024] The device according to the invention is configured to limit the effects related to the formation of electric arcs when the circuit is opened. Indeed, when an electrical circuit is opened, an electric arc maintaining the flow of current tends to form between the parts of the circuit that are moved apart, and it is advantageous to try to limit such arcs in intensity and / or duration.

[0025] Thus, the said cutting device may include a conduction bar 50. The said conduction bar 50 is fixed. It is housed, for example, in the said housing 6. The said bar 50 extends here parallel to the said actuation axis 10.

[0026] The device is further configured so that the conductor 4 is in contact, on the one hand, with a first 7 of the connection terminals and a first connection point 52 of the busbar 50 and, on the other hand, with a second 7' of the connection terminals and a second connection point 52' of the busbar 50, in the armed position. This increases the contact interfaces of the conductive elements between the moving parts, namely the conductor 4, and the fixed parts, namely the connection terminals 7, 7' and the connection points 52, 52' of the busbar 50. Such a configuration makes it possible to limit the energy of the breaking arcs that may occur at the interfaces when the circuit is opened, particularly compared to a device with only two contact interfaces.

[0027] According to a preferred aspect of the invention, said conductor comprises two said rings 9, 9'. Said device is then configured so that a first 9 of said rings establishes a current flow between said first connection terminal 7 and said first connection point 52 of the bar 50 and that a second 9' of said rings establishes a current flow between said second connection terminal 7' and said second connection point 52' of the bar 50.

[0028] The rings 9, 9' are, for example, coaxial and / or centered on the axis of movement 10. They are spaced apart along the direction of movement 10. They are located here respectively at the connection terminals 7, 7' and / or opposite longitudinal ends of the bar 50, the longitudinal ends forming the first and second connection points 52, 52'. In other words, an axial spacing of the connection terminals 7, 7' corresponds to an axial spacing of the rings 9, 9' and / or to a length of the bar 50. The first and second connection points 52, 52' and the connection terminals 7, 7' are respectively diametrically opposite with respect to the axis of movement 10.

[0029] As illustrated in the figure 3 According to an example of an embodiment of the device according to the invention, said device comprises a chamber 100 allowing compression of a fluid during the transition from the disarmed position to the armed position, under the effect of the displacement of said movable part 2. Said fluid is advantageously air.

[0030] The device further comprises at least one channel 102 connecting a zone 104, referred to as the blowing zone, to the compression chamber 100 so as to direct a flow of the fluid towards the blowing zone 104 to interrupt the electric arc forming during the transition from the armed to the disarmed position. The duration of electric arc formation is thus reduced.

[0031] Said chamber 100 and / or said channel 102 are formed here in said housing 6. Said channel 102 is oriented, for example, parallel to said axis of movement 10. Said chamber 100 is located at the longitudinal end of the moving member 2 opposite to that in contact with the actuator 12. Said actuator 12 has a different configuration here from that of the figures 1 et 2 It includes an actuating ferrule 112 configured to alternately lock or release a finger 114 linked to said movable member 2. It further includes an elastic member, not shown, configured to move said movable member 2 when said finger 114 is released. Said chamber 100 is traversed by said resetting member 36.

[0032] To the figure 3The device is shown in the disarmed position, with the volume of chamber 100 at its maximum after the fluid has expanded. Channel 102 is open and connects chamber 100 to the blowing zone 104. In the armed position, the moving member 2 is moved to the left, and the fluid in chamber 100 is pressurized by a reduction in the volume of said chamber 100. Channel 102 is then closed by a wall of the moving member 2. During the transition from the armed to the disarmed position, an electric arc forms at the various interface zones between the rings 9, 9', on the one hand, and the terminals and connection points, which are not visible in this figure. Simultaneously, channel 102 opens to allow the compressed fluid to flow towards the blowing zone 104. The latter corresponds to at least one of the interface zones.

[0033] Preferably, said conductor 2 includes an arc starting zone 106. Although this is not shown in the figure, which corresponds to an unarmed position, it is understood that, in the armed position, said arc starting zone 106 is advantageously located near an outlet end 108 of said channel, opposite an inlet end 110, and more precisely at a portion of a circumference of said outlet end 108 that is flush with said arc starting zone 106. The arc blowing thus takes place at one foot of the arc and can therefore occur at the very beginning of its formation.

[0034] The said initiation zone 106 is located, for example, at the level of the ring 9 furthest from the chamber 100. It is formed, in particular, by a pointed shape given to a lateral edge of the ring 9. The arc is thus blown at only one of the contact interfaces. It has indeed been observed that once the arc was blown at only one of the interfaces, this interrupted the arcs at the other contact interface(s).

[0035] The invention also relates to a battery module, not illustrated, comprising said cut-off device.

[0036] The module comprises at least one high-voltage battery for supplying electrical current to an electric machine used to drive a motor vehicle. A housing containing one or more electrical cells of the battery advantageously defines the casing of the disconnect device, at least for a portion thereof from which the reset element 36 protrudes to be accessible to the user when the moving part 2 is disarmed.

Claims

1. Cut-off device for an electric current, said device comprising a mobile member (2) provided with an electrical conductor (4), said device being configured to allow passage of said mobile member (2) between a first position, called armed position, allowing circulation of the current in the conductor (4), and a second position, called disarmed position, preventing said circulation of the current, said device further comprising an actuator (12), configured to trigger the passage of the mobile member (2) from the armed position to the disarmed position in the event of a fault on an electrical circuit in which said device is integrated, said device further comprising a resetting member (36) having a manual actuation zone (38), said actuation zone (38) forming a visual indicator of a disarmed state of said device and being configured to drive the mobile member (2) from the disarmed position to the armed position and to cause resetting of the actuator (12), characterized in that said device comprises a chamber (100) allowing compression of a fluid during the passage from the disarmed position to the armed position, under the effect of the movement of said mobile member (2), said device further comprising at least one channel (102) connecting a zone (104), called extinguishing zone, to said compression chamber (100) so as to direct a flow of said fluid towards said extinguishing zone (104) to cut off an electric arc that forms during the passage from the armed position to the disarmed position.

2. Device according to Claim 1, configured for passage between the armed position and the disarmed position by translation of the mobile member (2) and / or the resetting member (36) along an axis of movement (10).

3. Device according to either one of the preceding claims, wherein said device comprises a casing (6) defining a housing (8) accommodating said mobile member (2) and / or said actuator (12).

4. Device according to the preceding claim, wherein said casing (6) has a passage (40) for said resetting member (36) such that said resetting member (36) is able to be actuated by a user in said disarmed position and is flush with said casing (6) in the armed position.

5. Device according to any one of the preceding claims, further comprising two fixed connection terminals (7, 7') and a conduction bar (50), which is also fixed, said device being configured such that said conductor (4) is in contact, on the one hand, with a first (7) of said connection terminals and a first connection point (52) of said bar (50) and, on the other hand, with a second (7') of said connection terminals and a second connection point (52') of said bar (50), in the armed position.

6. Device according to the preceding claim, wherein said conductor (4) comprises two rings (9, 9'), said device being configured such that a first (9) of said rings establishes circulation of the current between said first connection terminal (7) and said first connection point (52) of the bar (50) and such that a second (9') of said rings establishes circulation of the current between said second connection terminal (7') and said second connection point (52') of the bar (50).

7. Device according to any one of the preceding claims, wherein said conductor (4) comprises a zone (106) for ignition of the arc that is situated near an outlet end (108) of said channel (102), in the armed position.

8. Battery module comprising a cut-off device according to any one of the preceding claims.

9. Motor vehicle comprising a module according to the preceding claim.

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