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

Abstract

A cut-off device for an electric current, said device comprising a movable member (2) provided with an electric conductor (4), said device being configured to cause said movable member (2) to pass between a first position, called armed, allowing a flow of current in the conductor (4), and a second position, called disarmed, cutting off said flow of current, said device further comprising an actuator (12), configured to trigger a passage of the movable member (2) from the armed position to the disarmed position in the event of a fault on an electric circuit in which said device is integrated, said device further comprising a resetting member (36) having a manual actuation zone (38), configured for a passage of the movable member (2) from the disarmed position to the armed position further causing a resetting of the actuator (12), said actuation zone (38) forming a visual indicator of a disarmed state of said device.Figure for abstract: Figure 1.

Description

Title of the invention: Cut-off device for an electric current, battery module comprising such a device and motor vehicle equipped with such a module

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

[0002] In this field, it is known to open an electrical power circuit used for charging and discharging a battery using manual cut-off devices. They make it possible to ensure that the current no longer flows, in particular in the event of intervention by emergency teams in an accident. Their limitation is that they are not triggered automatically. Cut-off devices are also known, for example from EP2538429, making it possible to open the circuit in the event of shocks but, once activated, they require intervention inside the battery modules in which they are installed to be replaced. Another of their disadvantages is that they do not give visual indications as to their triggering, whereas this is necessary in order to be able to ensure that the flow of current has indeed been interrupted.

[0003] The invention aims to at least partially overcome the above drawbacks and to this end proposes a cut-off device for an electric current, in particular direct current, said device comprising a movable member provided with an electrical conductor, said device being configured to allow said movable member to pass between a first position, called armed, allowing current to flow in the conductor, and a second position, called disarmed, preventing said current to flow, 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 drive the movable member from the disarmed position to the armed position and to further cause a re-arming of the actuator, said actuation zone forming a visual indicator of a disarmed state of said device.

[0004] Thanks to the movable member and the actuator, the triggering of the device according to the invention is automatic. In addition, the user has a status feedback on its correct triggering via the visual indicator of the reset member. Said reset member is also provided to be manual and capable to re-engage the actuator via the moving part, the device is reset simply from the outside.

[0005] According to various additional characteristics of the invention, which may be taken together or separately and which form as many embodiments of the invention: - said device is configured for a passage between the armed position and the disarmed position of the mobile member and / or the resetting member by a translation along a displacement axis, - said device is configured so that the translation of the resetting member causes the translation of the movable member, - said resetting member comprises a handle, - said actuator is configured to rearm itself under the effect of the translation of said moving member, - said device comprises a casing defining a housing accommodating said movable member, - said housing also accommodates said actuator, - said casing has a passage for said resetting member so that said resetting member can be actuated by a user in said disarmed position, - said device is configured so that said resetting member is flush with said casing in the armed position, - said device comprises two fixed terminals for connection to said circuit, - said device further comprises a fixed conduction bar, - said device is configured so that said conductor is in contact, on the one hand, with a first of said connection terminals and a first connection point of said strip and, on the other hand, with a second of said connection terminals and a second connection point of said strip, in the armed position, - said conductor comprises at least one ring, - said ring is split so as to have radial elasticity, - there are two of said rings, - said device is configured so that a first of said rings establishes a flow of current between said first connection terminal and said first connection point of the strip and that a second of said rings establishes a flow of current between said second connection terminal and said second connection point of the strip, in the armed position, - said device comprises a chamber allowing compression of a fluid when moving from the disarmed position to the armed position, under the effect of the movement of said mobile member, said device further comprising at least one channel connecting a zone, called a 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 when moving from the armed position to the disarmed position, - said fluid is air, - said channel and / or said chamber are formed in said casing, - said chamber is crossed by said resetting member, - said conductor comprises an arc striking zone, - said priming zone is located near an outlet end of said channel, in the armed position, - said priming zone is located at the level of that of said first and second rings furthest from said chamber.

[0006] The invention also relates to a battery module comprising the cut-off device described above.

[0007] Said module preferably comprises at least one high-voltage battery for supplying electric current to an electric machine used to drive a motor vehicle.

[0008] The invention also relates to a vehicle, in particular a motor vehicle, comprising such a battery module.

[0009] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during 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 appended schematic drawings among which:

[0010] [Fig-1] schematically illustrates, along an axial section plane, a first example of a device according to the invention, in an armed position;

[0011] [Fig.2] schematically illustrates, along an axial section plane, the device of [Fig.l], in a disarmed position;

[0012] [Fig.3], schematically illustrates, along an axial section plane, a second example of a device according to the invention, in a disarmed position.

[0013] The invention relates to a cut-off device for direct electric current. Such a device is intended, in particular, for cutting off a charging and / or discharging current of a high-voltage battery supplying an electric machine used to drive a motor vehicle. By "high voltage" is meant an electrical voltage greater than 100 V, for example approximately 400 V.

[0014] As illustrated in Figures 1 and 2, said device comprises a movable member 2, provided with an electrical conductor 4. Said movable member 2 here comprises an armature 3 carrying said electrical conductor 4. Said conductor 4 advantageously comprises at least one ring 9, 9'. Said ring 9, 9' is advantageously split so as to have radial elasticity for good contact with the other conductive members.

[0015] Said device is configured to cause said movable member 2 to pass between a first position, called armed, allowing a flow 5 of current in said conductor 4, along a line illustrated in dotted lines in [Fig.l], and a second position, called disarmed, cutting off said flow of current. Said disarmed position is illustrated in [Fig.2] in which it can be seen that the flow of current has been broken by the movement of the conductor 4.

[0016] Said device here comprises a casing 6 defining a housing 8 receiving said movable member 2. Said casing 6 has, for example, a cylindrical and / or parallelepiped shape. Said device comprises two fixed connection terminals 7, 7' to said circuit. Said connection terminals 7, 7' are located, for example, on said casing 6.

[0017] Preferably, said device is configured for a passage of the movable member 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 casing 6. In the illustrated embodiment, the movable member 2 is moved from left to right when passing from the armed position to the disarmed position.

[0018] Said device further comprises 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. The triggering of the device according to the invention is thus automatic. Preferably, said housing 8 also accommodates said actuator 12.

[0019] By way of non-limiting example, according to a first variant, said actuator 12 comprises a fault current detector 14 and an elastic member 16. Said device is configured so that the fault current detector 14 keeps said elastic member 16 in a compressed state as long as no fault current is detected and releases said elastic member 16 in the opposite case. Said elastic member 16, once free, relaxes and causes the moving member 2 to move from the armed position to the disarmed position.

[0020] Said fault current detector comprises, for example, an electromagnet 18 linked to a drive shaft 22. Said drive shaft 22 is movable in rotation around said displacement axis 10. Said elastic member 16 comprises a spring 28 and a movable support 30. Said spring 28 comprises a plurality of turns. One 32 of said turns, called the first end turn, is connected to a first end of the movable support 30. Said first turn 32 is further in contact with said movable member 2. Another 34 of said turns, called the second end turn, is in contact with a body 24 of the casing 6, in the armed position. Said movable support 30 comprises 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 movable member 2.

[0021] In the event of the occurrence of a fault current, 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.

[0022] Said device further comprises a resetting member 36. Said resetting member has a manual actuation zone 38, configured for a passage of the movable member 2 from the disarmed position to the armed position, further causing a resetting of the actuator 12. Said actuation zone 38 further forms a visual indicator of a disarmed state of said device. Thanks to said actuation zone 38, the user thus has the possibility of resetting the device from the outside as well as a status feedback on its correct triggering.

[0023] Said casing 6 here has for this purpose a passage 40 for said resetting member 36 so that said resetting member 36 can be actuated by a user in said disarmed position. Said resetting member 36 comprises, for example, a handle forming said manual actuation zone 38. Said handle extends, for example, along said axis of movement 10. The actuator 12 and the handle of the resetting member 36 are here arranged on either side of said movable member 2, along said axis of movement 10.

[0024] In the illustrated embodiment, the user performs a reset by actuating the handle of the reset member 36 from right to left. The movable member 2 then returns to the armed position and the spring 38 is compressed again while the rod 20 of the movable support 30 is housed in said groove 26. The circulation 5 of the current can thus occur again, as in [Fig.l]. In this same figure, it can be seen that said device is configured so that said reset member 36 is flush with said casing 6 in the armed position. In other words, the reset member 36 is visible only from a longitudinal end 42 of said handle and cannot be actuated from the outside.

[0025] Said resetting member 36 is preferably movable in translation along said axis of movement 10. Said device is configured so that the translation of the resetting member 36 causes the translation of the movable member 2, from the position disarmed 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. Said actuator 12 is configured to re-arm under the effect of the translation of said movable member 2.

[0026] Alternatively or cumulatively with the above, said device according to the invention is configured to limit the effects linked to the formation of electric arcs when the circuit is opened. Indeed, when an electric circuit is opened, an electric arc maintaining the flow of current tends to form between the parts of the circuit that are moved away from each other and it is advantageous to seek to limit such arcs in intensity and / or duration.

[0027] Thus, said cut-off device comprises a conduction bar 50. Said conduction bar 50 is fixed. It is housed, for example, in said casing 6. Said bar 50 extends here parallel to said actuation axis 10.

[0028] Said device is further configured so 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 strip 50 and, on the other hand, with a second 7' of said connection terminals and a second connection point 52' of said strip 50, in the armed position. This increases the contact interfaces of the conduction members 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 connection strip 50. Such a configuration makes it possible to limit the energy of the breaking arcs likely to occur at said interfaces at the time of opening the circuit, in particular compared to a device comprising only two contact interfaces.

[0029] According to this 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 flow of current between said first connection terminal 7 and said first connection point 52 of the strip 50 and that a second 9' of said rings establishes a flow of current between said second connection terminal 7' and said second connection point 52' of the strip 50.

[0030] Said rings 9, 9' are, for example, coaxial and / or centered on said axis of movement 10. They are spaced from one another in said direction of movement 10. Here they are located respectively in line with said connection terminals 7, 7' and / or opposite longitudinal ends of said strip 50, said longitudinal ends forming said first and second connection points 52, 52'. In other words, an axial spacing of said connection terminals 7, 7' corresponds to an axial spacing of said rings 9, 9' and / or to a length of said strip 50. Said first and second connection points 52, 52' and said terminals connection 7, 7' are respectively diametrically opposed with respect to the displacement axis 10.

[0031] As illustrated in [Fig. 3], according to another exemplary embodiment of the device according to the invention, 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 fluid is advantageously air.

[0032] Said device further comprises at least one channel 102 connecting a zone 104, called a blowing zone, to said compression chamber 100 so as to direct a flow of said fluid towards said blowing zone 104 to cut the electric arc forming when moving from the armed position to the disarmed position. The duration of establishment of the electric arcs is thus reduced.

[0033] Said chamber 100 and / or said channel 102 are here formed in said casing 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 movable member 2 opposite that in contact with the actuator 12. Said actuator 12 here has a configuration different from that of FIGS. 1 and 2. It comprises an actuable ferrule 112 configured to alternately block or release a finger 114 linked to said movable member 2. It further comprises an elastic member, not shown, configured to move said movable member 2 when said finger 114 is released. Said chamber 100 is crossed by said resetting member 36.

[0034] In [Fig. 3], the device is illustrated in the disarmed position and a volume of the chamber 100 is maximum, after expansion of the fluid. The channel 102 is open and connects the chamber 100 to the blowing zone 104. In the armed position, the movable member 2 is moved to the left and the fluid in the chamber 100 is under pressure by a reduction in the volume of said chamber 100. The channel 102 is then closed by a wall of the movable member 2. When moving from the armed position to the disarmed position, an electric arc is formed at the various interface zones between the rings 9, 9', on the one hand, and said terminals and connection points, not visible in this figure. At the same time, said channel 102 opens to allow the compressed fluid to pass towards said blowing zone 104. The latter corresponds to at least one of said interface zones.

[0035] Preferably, said conductor 2 comprises an arc striking zone 106. Although this is not in the figure which corresponds to a disarmed position, it is understood that, in the armed position, said striking zone 106 is advantageously located near an outlet end 108 of said channel, opposite an inlet end 110, and more precisely at the level of a part of a circumference of said outlet end 108 flush with said initiation zone 106. The blowing thus takes place at one foot of the arc and can therefore occur at the very start of its formation.

[0036] Said ignition zone 106 is located, for example, at the level of that 9 of said first and second rings furthest from said chamber 100. It is formed, in particular, by a pointed shape given to a lateral edge of said ring 9. The arc is thus blown out at only one of the contact interfaces. It has in fact been observed that once the arc has been blown out at only one of said interfaces, this interrupts the arcs at the level of the other(s) of said contact interface(s).

[0037] The invention also relates to a battery module, not illustrated, comprising said cut-off device.

[0038] Said module comprises at least one high-voltage battery for supplying electrical current to an electrical machine used to drive a motor vehicle. A housing housing one or more electrical cells of said battery advantageously defines the casing of said cut-off device, at least for a part of the latter from which said resetting member 36 projects to be accessible to the user, in the disarmed position of the mobile member 2.

Claims

Claims

1. A device for cutting off an electric current, said device comprising a movable member (2) provided with an electric conductor (4), said device being configured to allow said movable member (2) to pass between a first position, called armed, allowing current to flow in the conductor (4), and a second position, called disarmed, preventing said current to flow, said device further comprising an actuator (12), configured to trigger the passage of the movable member (2) from the armed position to the disarmed position in the event of a fault on an electric circuit in which said device is integrated, said device further comprising a reset 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 movable member (2) from the disarmed position to the armed position and to cause a rearming of the actuator (12), said device comprising 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 movable member (2), said device further comprising at least one channel (102) connecting a zone (104), called a blowing zone, to said compression chamber (100) so as to direct a flow of said fluid towards said blowing zone (104) to cut an electric arc forming during the passage from the armed position to the disarmed position.,

2. Device according to claim 1 configured for a passage between the armed position and the disarmed position by a translation of the movable member (2) and / or the resetting member (36) along a displacement axis (10).

3. Device according to any one of the preceding claims in which said device comprises a casing (6) defining a housing (8) receiving said movable member (2) and / or said actuator (12).

4. Device according to the preceding claim in which said casing (6) has a passage (40) for said resetting member (36) so that said resetting member (36) can 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 strip (50), also fixed, said device being configured so 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 strip (50) and, on the other hand, with a second (7') of said connection terminals and a second connection point (52') of said strip (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 so that a first (9) of said rings establishes a flow of current between said first connection terminal (7) and said first connection point (52) of the strip (50) and that a second (9') of said rings establishes a flow of current between said second connection terminal (7') and said second connection point (52') of the strip (50).

7. 7. Device according to any one of the preceding claims in which said conductor (4) comprises an arc striking zone (106) located near an output end (108) of said channel (102), in the armed position.

8. A 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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