Pyrotechnic circuit breaker
The pyrotechnic circuit breaker addresses operation variability by using a die to plastically deform the electrical conductor, ensuring stable activation and reliable circuit interruption.
Patent Information
- Application Number
- FR2023011429
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-10-20
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2043-10-20
AI Technical Summary
Existing circuit breakers face variability in operation due to a free strand of electrical conductor moving within the circuit breaker, causing disruptions, and ensuring a stable activated position for the cutting piston is difficult due to high travel speeds and impacts.
A pyrotechnic circuit breaker design featuring a die with a recessed cavity that imposes plastic deformation on the electrical conductor, ensuring controlled movement and stable activation by using a deformed conductor as a shock absorber and obstacle for the cutting piston.
The design achieves reproducible and reliable circuit interruption with controlled conductor movement and stable piston activation, reducing disruptions and impacts.
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Abstract
Description
Title of the invention: Pyrotechnic circuit breaker Technical field of the invention
[0001] The present invention relates generally to circuit breakers mounted in motor vehicles for interrupting an electrical circuit in an emergency. Typically used for electric or hybrid vehicles, the circuit breakers according to the invention can be used to interrupt a power and / or drivetrain supply circuit. Such electrical circuits may have voltages of several hundred or thousands of volts, and / or carry currents of several hundred or thousands of amperes. State of the art
[0002] It is known in the prior art of circuit breakers to interrupt an electrical conductor, and as shown in document FR3017240A1, it is possible to create a free strand of electrical conductor, completely separated from the rest of the original electrical conductor after the circuit is interrupted. However, this system can exhibit variability if the free strand of electrical conductor moves within the circuit breaker and cause a disruption of the expected operation, particularly if it obstructs the movement of the cutting piston. Nevertheless, generating a free strand of electrical conductor may be desirable to increase the voltage generated by the circuit breaker during the cutting operation, since two electrical arcs can form on either side of the free strand of electrical conductor, which increases the voltage across the circuit breaker and promotes a rapid interruption of the electrical current flow.Furthermore, the cutting piston, at the end of its stroke, must be decelerated to be immobilized in an activated position (or a cutting position) which must be maintained and repeatable (for example, to form a closed internal chamber in the circuit breaker). Guaranteeing a stop in this activated position can be difficult due to the high travel speeds and the resulting impacts with the housing and / or rebounds. Description of the invention
[0003] One object of the present invention is to overcome the drawbacks of the prior art mentioned above and, in particular, firstly, to provide a circuit breaker arranged to interrupt an electrical circuit in a more reproducible and reliable manner. In particular, one object of the present invention may be to provide a circuit breaker arranged to interrupt an electrical circuit in a more reproducible and reliable manner even if a free strand of electrical conductor is formed. In particular, one object of the present invention may be to provide a circuit breaker arranged to interrupt an electrical circuit in which the activated position of the cutting piston is guaranteed in a more reproducible and reliable manner.
[0004] To this end, a first aspect of the invention relates to a pyrotechnic circuit breaker comprising: - a housing, - an electrical conductor passing at least partially through the casing, - a cutting piston, housed in the casing, movable between a rest position and an activated position, and arranged to cut the electrical conductor when moving from the rest position to the activated position, - at least one die, arranged in the housing to support at least a portion of the electrical conductor during at least part of the cutting of the electrical conductor by the cutting piston, - at least one pyrotechnic actuator, housed in the casing, and arranged to move the cutting piston from the rest position to the activated position, characterized in that the die comprises a recessed cavity designed to impose plastic deformation on said at least one supported portion of the electrical conductor during the cutting of the electrical conductor by the cutting piston. According to this embodiment, at least a portion of the electrical conductor is deformed irreversibly or plastically, such that: - The position is better controlled because the overall size of the electrical conductor is increased; the electrical conductor has less possibility of moving without interfering with the rest of the circuit breaker, and / or - the cutting piston imposes plastic or irreversible deformation, thereby transferring energy to the electrical conductor, which dampens or slows down the cutting piston moving towards the activated position, and / or - the deformed portion of the electrical conductor can then act as a shock absorber for the cutting piston when it reaches the activated position.
[0005] The invention can then be defined with the following characteristics, taken individually or in combination.
[0006] According to one embodiment, the plastic deformation imposed on the electrical conductor results in an irreversible deformation, displacement, or bend in the electrical conductor along a direction parallel to or aligned with the direction of movement of the cutting piston. In other words, the electrical conductor has a deformed area that has been displaced along the direction of movement of the cutting piston. The electrical conductor with such an irreversible deformation can, of course, be plastically (or to a lesser extent elastically) deformed again subsequently.
[0007] According to one embodiment, preferably after the electrical conductor has been cut, at least one deformed area of the electrical conductor is arranged to form a braking obstacle for the cutting piston as it moves toward the activated position. The deformed area of the electrical conductor acts as a decelerator or shock absorber for the cutting piston, allowing it to stop gradually in the activated position, which is then more reproducible. Bouncing or shocks to the housing are eliminated or at least dampened.
[0008] According to one embodiment, the electrical conductor has a conductor axial direction, and wherein the recess has a recess axial direction substantially aligned with the conductor axial direction. The recess may be a groove aligned with an axial direction of the electrical conductor.
[0009] According to one embodiment, the die has a support surface arranged opposite and / or parallel to the electrical conductor, and the recessed imprint forms a notch in the support surface in a direction opposite to the electrical conductor, before cutting. Such a notch causes the electrical conductor to collapse or sag when sheared by the cutting piston, leading to plastic and / or irreversible deformation.
[0010] According to one embodiment, the cutting piston has at least two cutting blades such as to form a free strand of electrical conductor when the electrical conductor is cut, and the free strand of electrical conductor comprises or forms said at least a portion of the electrical conductor supported by the die. Consequently, the free strand of electrical conductor will be plastically deformed during the movement of the cutting piston: the indentation causes a lack of support between the die and the electrical conductor, which leads to a bend in the free strand of electrical conductor.
[0011] According to one embodiment, the distance separating said at least two cutting blades (in particular along a direction transverse to a direction of movement of the cutting piston) is less than an overall dimension of the free strand of plastically deformed electrical conductor (in particular along a direction of movement of the cutting piston). Thus, the free strand cannot turn back on itself between the cutting blades: it abuts against the sides of the cutting blades.
[0012] According to one embodiment, in the activated position, the cutting piston and the die form a closed enclosure around the free strand of electrical conductor.
[0013] According to one embodiment, in the activated position, the cutting piston and the die are separated by a gap which, along a direction of movement of the cutting piston, has a dimension smaller than a length or a width of the free strand of the electrical conductor. Consequently, this limits the risk of Reversal of the free strand of electrical conductor could obstruct the movement of the cutting piston towards the activated position. The plastic deformation imposed on the free strand of electrical conductor increases its size and makes such a reversal more difficult or even impossible.
[0014] According to one embodiment, the plastic deformation imposed on the electrical conductor includes or consists at least of a bend along a fold line.
[0015] According to one embodiment, the fold line is parallel or aligned with an axial direction of the electrical conductor, the axial direction being defined before the cutting of the electrical conductor.
[0016] According to one embodiment, the cutting piston has at least one progressive or inclined cutting edge, so as to terminate the cutting of the electrical conductor in an area opposite or adjacent to the recessed imprint. Thus, when the cut occurs opposite the imprint, the remainder of the electrical conductor is detached and can move under the effect of plastic deformation.
[0017] According to one embodiment, the recessed cavity is arranged opposite a zone arranged in the middle of the electrical conductor. The cutting forces are balanced on each side of the electrical conductor.
[0018] According to one embodiment, the deformation of the electrical conductor imposes a V-shape on the electrical conductor. Such a V presents an obstruction (depending on the direction of movement of the cutting piston) which makes it difficult to reverse or pivot the electrical conductor (typically the free strand of the electrical conductor).
[0019] According to one embodiment, the electrical conductor has a thickness to be cut, and the cut cavity has a depth of at least 50%, preferably at least 80%, of the thickness to be cut. According to one embodiment, the cut cavity has a depth of at least 0.25 mm, preferably at least 0.5 mm, preferably at least 0.8 mm, preferably at least 1 mm, preferably at least 1.25 mm, preferably at least 1.5 mm.
[0020] According to one embodiment, the electrical conductor has a width to be cut, and the cut cavity has a width of at least 30%, preferably at least 40%, of the width to be cut. According to one embodiment, the cut cavity has a width of at least 5 mm, preferably at least 7.5 mm, preferably at least 10 mm, preferably at least 12.5 mm, preferably at least 155 mm. Description of the figures
[0021] Other features and advantages of the present invention will become more apparent upon reading the following detailed description of an embodiment. of the invention given by way of non-limiting example and illustrated by the attached drawings, in which:
[0022] [Fig.1] represents a cross-sectional view of a circuit breaker according to the invention comprising a housing, an electrical conductor and a cutting piston, the cutting piston occupying a rest position and the cutting of [Fig.1] being carried out along a cutting plane comprising an axis parallel to a direction of movement of the cutting piston and an axis parallel to a longitudinal direction of the electrical conductor;
[0023] [Fig.2] represents a cross-sectional view of the circuit breaker of [Fig.1], in a plane of cutting tool comprising an axis parallel to the direction of movement of the cutting piston and an axis transverse to a longitudinal direction of the electrical conductor, the cutting piston occupying the rest position;
[0024] [Fig.3] represents the cross-sectional view of the circuit breaker of [Fig.2], the cutting piston having left the resting position and occupying an intermediate cutting position;
[0025] [Fig.4] represents the cross-sectional view of the circuit breaker of [Fig.2], the cutting piston occupying a final cutting position known as the activated position.
[0026] Detailed description of embodiment(s)
[0027] Figure [1] represents a pyrotechnic circuit breaker comprising: - a housing 10 formed by an upper housing 11 and a lower housing 12, - an electrical conductor 20 passing at least partially through the housing 10, - a cutting piston 30, housed in the housing 10, movable between a rest position (occupied position [Fig. 1]) and an activated position (occupied position [Fig. 4]), and arranged to cut the electrical conductor 20 when passing from the rest position to the activated position, - at least one die 40, arranged in the housing 10 to support at least a portion of the electrical conductor 20 during at least part of the cutting of the electrical conductor by the cutting piston, - at least one pyrotechnic actuator 50, housed in the casing 10, and arranged to move the cutting piston 30 from the rest position to the activated position.
[0028] It can be noted that the cut of [Fig.1] is made according to a cutting plane comprising an axis parallel to a direction of movement of the cutting piston 30 and an axis parallel to a longitudinal direction of the electrical conductor 20.
[0029] In detail, and with regard to the housing 10, the upper housing 11 includes an internal bore which receives the cutting piston 30 in a sliding connection. The internal bore is closed by an igniter support 13 which receives the pyrotechnic actuator, here an electro-pyrotechnic igniter comprising in particular a loading case 51 and connection pins 52.
[0030] The lower housing 12 includes housings for heat sinks 60, and the body of the lower housing 12 forms dies 40 with in particular a first matrix 41, a second matrix 42 each supporting a portion of the electrical conductor 20 (it being understood that the electrical conductor 20 is supported by the internal side walls of the lower housing 12 which also form matrices), the second matrix 42 specifically comprising a recessed imprint 43.
[0031] The housing 10 also includes a frame 13 overmolded on the electrical conductor 20 to allow the electrical conductor 20 to be positioned easily in the housing 10, with the frame 13 sandwiched between the upper housing 11 and the lower housing 12.
[0032] The frame 13 can be formed of plastic material, for example polymer, the upper housing 11 can be formed of plastic material, for example polymer and can include an internal (as shown) or external metal insert, and the lower housing 12 can be formed of plastic material, for example polymer and can also include an internal or external metal insert.
[0033] The electrical conductor 20 is therefore supported by the frame 13 and comprises: - two external connection ends 21 to the housing 10, - a first internal portion 23 supported by the first matrix 41, - a second internal portion 24 supported by the second matrix 42, - section reductions 22 arranged between the various portions mentioned above, in order to assist in cutting or bending the electrical conductor 20. In the configuration of [Fig.1] with the cutting piston in the rest position, the electrical conductor 20 is continuous, in one piece with all portions still connected together.
[0034] The cutting piston 30 is housed in the casing 10 and is essentially defined as follows: - a combustion chamber 14 arranged between the cutting piston 30 and the pyrotechnic actuator 50, - a cutting chamber 15 arranged between the cutting piston 30 and the electrical conductor 20 and / or the dies 40.
[0035] More specifically, the cutting piston 30 includes, in particular: - a first cutting blade 31 arranged in the cutting chamber 15, - a second cutting blade 32 arranged in the cutting chamber 15, - a third cutting blade 33 arranged in the cutting chamber 15, - a support surface 37 arranged between the second cutting blade 32 and the third cutting blade 33, - a cylindrical body 34, received in the bore of the upper housing 11, - an O-ring 36, supported by the cylindrical body 34, - a well 35 formed in the cylindrical body to define the combustion chamber 14. Consequently, it can be noted that the electrical conductor 20 will be cut in three distinct places by the first cutting blade 31, the second cutting blade 32, and the third cutting blade 33. Two free strands of electrical conductor will be formed, essentially from the first internal portion 23 and the second internal portion 24.
[0036] Fig. 2 represents a cross-sectional view of the circuit breaker of Fig. 1, in a cutting plane comprising an axis II-II of Fig. 1 parallel to the direction of movement of the cutting piston 30 and comprising an axis transverse to a longitudinal direction of the electrical conductor 20, the cutting piston 30 always occupying the rest position.
[0037] The following points can be noted [Fig.2]: - the axis II-II of [Fig.1], parallel to the direction of movement of the cutting piston 30, passes through the second internal portion 24 of the electrical conductor 20, supported by the second die 42, - the second die 42 therefore has a hollow imprint 43 arranged under the second internal portion 24 opposite the cutting piston 30, so that the support provided by the second die 42 to the second internal portion 24 is partial, - the third cutting blade 33 of the cutting piston 30 is beveled and has an inclined profile relative to the second internal portion 24.
[0038] The recessed imprint 43 is present in this example: - a width approximately half the width of the second internal portion 24 supported by the second matrix 42, - a depth in the second matrix 42 approximately equivalent to the thickness of the second internal portion 24 supported by the second matrix 42, - a central position with respect to the second internal portion 24 supported by the second matrix 42.
[0039] The third cutting blade 33 of the cutting piston 30 is beveled in an inverted V relative to the second internal portion 24 supported by the second die 42, at an angle of approximately 5° to 10° in this example, and / or over a height approximately equivalent to the thickness or half the thickness of the second internal portion 24 supported by the second die 42. It can be provided that at least the second cutting blade 32 (and / or the first cutting blade 31) has the same profile as the third cutting blade 33.
[0040] Consequently, during the descent of the cutting piston 30 from the rest position, the electrical conductor 20 (and in particular the second internal portion 24) will be progressively cut by the second cutting blade 32 and the third cutting blade 33. The cut will begin at the edges of the second internal portion 24 and end at the center, precisely where the recessed imprint 43 is located. The second internal portion 24 is not supported at the level of the recessed imprint 43 and has its edges already cut, a plastic deformation will be imposed on the electrical conductor 20 and in particular on the second internal portion 24 during the cutting.
[0041] Indeed, [Fig. 3] shows the cross-sectional view of the circuit breaker of [Fig. 2], the cutting piston 30 having left the rest position of Figures 1 and 2 and occupying an intermediate cutting position. The third cutting blade 33 is shown in dashed lines because it has passed behind the second die 42 and the second internal portion 24. It can be noted that the position of the cutting piston 30 is that in which the third cutting blade 33 is just finishing cutting the second internal portion 24. Consequently, all the cutting force is concentrated on the middle of the second internal portion 24, which is now supported only by the recessed imprint 43.The central cutting force therefore imposes a collapse, a sagging or a movement of the central part of the second internal portion 24 in the hollow imprint 43 and a plastic deformation of the second internal portion 24 due to the edges of the second internal portion 24 bearing on the sides of the hollow imprint 43. The plastic deformation causes a V-shaped deformation of the second internal portion 24.
[0042] Considering [Fig. 1], it can be noted that the second internal portion 24, now separated from the rest of the electrical conductor 20, is arranged between the second cutting blade 32 and the third cutting blade 33. Indeed, at this stage of the movement of the cutting piston 30 of [Fig. 3], the second cutting blade 32 and the third cutting blade 33 surround the second internal portion 24 and the second die 42.
[0043] The second cutting blade 32 and the third cutting blade 33 thus gradually approach the second die 42, and their sides come into contact to form a closed space. The V-shaped deformation imposed on the second internal portion 24, visible [Fig. 3], significantly increases its size along the direction of movement of the cutting piston 30. The second internal portion 24, forming a free strand at this stage, could flip over in the housing between the second cutting blade 32 and the third cutting blade 33, but the imposed V-shaped deformation considerably limits the risk of such a flip.
[0044] Indeed, such a reversal around an axis normal to the plane of [Fig. 1] or horizontal on [Fig. 3] is limited or prohibited because the edges of the V increase the overall bulk of the second internal portion 24 forming a free strand and can come to rest on the sides of the second cutting blade 32 or the third cutting blade 33. The position of the second internal portion 24 forming a free strand is better controlled during operation.
[0045] Figure 4 shows the cross-sectional view of the circuit breaker of Figure 2, the cutting piston 30 occupying a final cutting position, referred to as the activated position, in which the electrical conductor 20 is completely cut and the cutting piston 30 is at the end of its stroke.
[0046] It can be noted that the bearing surface 37 came into contact with the second internal portion 24, which was again deformed by the cutting piston 30 to regain a flat shape. Thus, the cutting piston 30 was dampened or slowed by the second internal portion 24 before reaching the activated position. This deformation, imposed by the obstacle formed by the second internal portion 24, therefore slowed / damped the cutting piston in such a way as to limit impacts between the housing 10 and the rebound or backward movement of the cutting piston 30. The final activated position and / or the robustness of operation is better guaranteed with the second internal portion 24 being deformed initially and then redistorted. Industrial application
[0047] A circuit breaker according to the present invention, and its manufacture, are capable of industrial application.
[0048] It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the different embodiments of the invention described herein without departing from the scope of the invention. In particular, the electrical conductor can be cut into fewer or more parts or positions. The recessed cavity can be of different shapes, or several recessed cavities can be provided in several locations.
Claims
Demands
1. Pyrotechnic circuit breaker comprising: - a housing (10), - an electrical conductor (20) passing at least partially through the housing (10), - a cutting piston (30), housed in the housing (10), movable between a rest position and an activated position, and arranged to cut the electrical conductor (20) when passing from the rest position to the activated position, - at least one die (40), arranged in the housing (10) to support at least a portion of the electrical conductor (20) during at least part of the cutting of the electrical conductor (20) by the cutting piston (30), - at least one pyrotechnic actuator (50), housed in the housing (10), and arranged to move the cutting piston (30) from the rest position to the activated position,characterized in that the die (40) comprises a recessed imprint (43) designed to impose plastic deformation on said at least a supported portion of the electrical conductor (20) during the cutting of the electrical conductor (20) by the cutting piston (30), wherein the electrical conductor (20) has a conductor axial direction, and wherein the recessed imprint (43) has an imprint axial direction substantially aligned with the conductor axial direction.
2. Pyrotechnic circuit breaker according to claim 1, wherein at least one deformed area of the electrical conductor (20) is arranged to form a braking obstacle to the cutting piston (30) during its movement to the activated position.
3. Pyrotechnic circuit breaker according to any one of claims 1 to 2, wherein the die (40) has a support surface arranged opposite and / or parallel to the electrical conductor (20), and wherein the recessed imprint (43) forms a recess in the support surface in a direction opposite to the electrical conductor (20), before breaking.
4. Pyrotechnic circuit breaker according to any one of claims 1 to 3, wherein the cutting piston (30) has at least two cutting blades (31, 32, 33) so as to form a free strand of conductor electrical (20) during the cutting of the electrical conductor (20), and in which the free strand of electrical conductor (20) comprises or forms said at least a portion of the electrical conductor (20) supported by the matrix (40).
5. Pyrotechnic circuit breaker according to claim 4, wherein, in the activated position, the cutting piston (30) and the die (40) form a closed enclosure around the free strand of electrical conductor (20).
6. Pyrotechnic circuit breaker according to any one of claims 1 to 5, wherein the plastic deformation imposed on the electrical conductor (20) comprises or consists at least of a bend along a fold line.
7. Pyrotechnic circuit breaker according to claim 6, wherein the fold line is parallel or aligned with an axial direction of the electrical conductor (20), the axial direction being defined before the cutting of the electrical conductor (20).
8. Pyrotechnic circuit breaker according to any one of claims 1 to 7, wherein the cutting piston (30) has at least one progressive or inclined cutting edge, so as to terminate the cutting of the electrical conductor (20) in an area opposite or adjacent to the recessed imprint (43).
9. Pyrotechnic circuit breaker according to any one of claims 1 to 8, wherein the recessed imprint (43) is arranged opposite an area arranged in the middle of the electrical conductor (20).