CN118056257A

CN118056257A - Active/passive fuse module

Info

Publication number: CN118056257A
Application number: CN202280051156.5A
Authority: CN
Inventors: 甘尼许·纳加拉杰·钱纳柯萨韦卢; 恩格尔贝特·海茨曼赛德; 彼得·珀尔特尔; 德里克·拉西尼
Original assignee: Astotec Automotive GmbH; Ritford International Holdings Ltd
Current assignee: Astotec Automotive GmbH; Ritford International Holdings Ltd
Priority date: 2021-07-20
Filing date: 2022-07-20
Publication date: 2024-05-17
Also published as: EP4374408A1; WO2023003936A1

Abstract

An active/passive fuse module comprising: a base; a bus bar disposed on the base and including a fuse element extending over a cavity in a top surface of the base and having a plurality of weak points formed therein; a Pyrotechnic Interrupter (PI) disposed above the base and including a piston disposed within the shaft above the fuse element, the piston having an edge with a geometry corresponding to a geometry defined by a weak point in the fuse element, a first pyrotechnic igniter coupled with the controller and configured to detonate and force the piston through the fuse element upon receipt of an activation signal from the controller, and a second pyrotechnic igniter coupled with the bus bar through a pair of leads and configured to detonate and force the piston through the fuse element upon an increase in voltage across the leads.

Description

Active/passive fuse module

Cross Reference to Related Applications

The present application is a continuation-in-part application of U.S. non-provisional patent application Ser. No. 17/021,774, filed on even 15, 9, 2020, which claims the benefit of U.S. provisional patent application Ser. No. 62/948,728, filed on 16, 12, 2019, and U.S. provisional patent application Ser. No. 63/036,613, 6, 2020, which are incorporated herein by reference in their entireties.

Technical Field

The present disclosure relates generally to the field of circuit protection devices and more particularly to active/passive fuse modules that include both active and passive circuit protection elements.

Background

Fuses are typically implemented in electrical systems for providing overcurrent protection. Most fuses are "passive" devices that include a fuse element configured to carry a rated amount of current during normal operation. If the current flowing through the fuse element exceeds the rated current of the fuse element, the fuse element will melt, decompose or otherwise separate, thereby blocking the current to prevent or mitigate damage to the connected electrical components.

In some cases, it may be desirable to create a physical opening "actively" in the circuit, regardless of the amount of current flowing through the circuit. For example, if a car collides, it may be desirable to physically open a circuit in the car to ensure that the connected electrical components are powered down to mitigate the risk of fire and/or electric shock following a collision. For this purpose, so-called pyrotechnic interrupters (pyrotechnic interrupter, PI) have been developed which can be selectively actuated to interrupt the flow of current in the electrical circuit upon the occurrence of a specific event. For example, in the event of a car crash, a controller (e.g., an airbag control unit, a battery management system, etc.) may send an activation signal to the PI, causing a pyrotechnic igniter within the PI to be fired. The resulting increase in pressure within the PI rapidly forces the piston or blade to pierce the conductor extending through the PI. The current flowing through PI is thereby interrupted and the piston formed of dielectric material provides an electrically insulating barrier between the separated portions of the conductor to prevent arcing therebetween.

In certain applications, it may be desirable to implement both passive and active circuit protection elements. It may be further desirable to implement such elements in compact, space-saving dimensions that facilitate ease of installation.

It is with respect to these and other considerations that the present improvements may be useful.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

An active/passive fuse module according to a non-limiting embodiment of the present disclosure may include a chassis; a bus bar disposed on the top surface of the base and including a fuse element and first and second terminal portions extending from opposite ends of the fuse element, the fuse element extending over a cavity in the top surface of the base and having a plurality of weak points formed therein; a Pyrotechnic Interrupter (PI) disposed above the base, the PI including a piston disposed within a shaft above the fuse element, a first pyrotechnic igniter coupled to the controller and having an edge with a geometry corresponding to a geometry of a pattern defined by points of weakness in the fuse element, and a second pyrotechnic igniter coupled to the bus bar by a pair of leads, the first pyrotechnic igniter configured to detonate and force the piston through the fuse element upon receipt of an activation signal from the controller, the second pyrotechnic igniter configured to detonate and force the piston through the fuse element upon an increase in voltage across the leads.

An active/passive fuse module according to another non-limiting embodiment of the present disclosure may include an electrically insulating base; a bus bar disposed on a top surface of the base and including a fuse element extending over a cavity formed in the top surface of the base and having a plurality of weak points formed therein, and first and second terminal portions extending from opposite ends of the fuse element; a Pyrotechnic Interrupter (PI) disposed above the base, the PI including a piston disposed within a shaft above the base, a current sensing module connected to the bus bar and configured to measure current flowing through the bus bar, and a pyrotechnic igniter coupled to the controller and coupled to the current sensing module, the piston having an edge with a geometry corresponding to a geometry of a pattern defined by points of weakness in the fuse element, wherein the pyrotechnic igniter is configured to detonate and force the piston through the fuse element upon receipt of an activation signal from at least one of the controller and the current sensing module.

A fuse module according to another non-limiting embodiment of the present disclosure may include: a base; a bus bar disposed on a top surface of the base and including a fuse element extending over a cavity in the top surface of the base and having a plurality of weak points formed therein, and first and second terminal portions extending from opposite ends of the fuse element; a Pyrotechnic Interrupter (PI) disposed above the base, the PI including a piston disposed within a shaft above the fuse, a first pyrotechnic igniter coupled to the controller, the piston having an edge with a geometry corresponding to a geometry of a pattern defined by points of weakness in the fuse element, and a pyrotechnic igniter coupled to the bus bar by a pair of leads, the pyrotechnic igniter configured to detonate and force the piston through the fuse element upon an increase in voltage across the leads.

Drawings

Fig. 1 is a cross-sectional view illustrating an embodiment of an active/passive fuse module in a non-actuated state according to the present disclosure;

fig. 2 is a sectional view illustrating the active/passive fuse module shown in fig. 1 in an actuated state;

fig. 3 is a cross-sectional view illustrating another embodiment of an active/passive fuse module according to the present disclosure;

Fig. 4 is a cross-sectional view illustrating another embodiment of an active/passive fuse module according to the present disclosure;

fig. 5A is a cross-sectional view illustrating another embodiment of an active/passive fuse module according to the present disclosure;

FIG. 5B is a top view of the bus bar of the active/passive fuse module shown in FIG. 5A;

Fig. 6A is a cross-sectional view illustrating another embodiment of an active/passive fuse module according to the present disclosure;

Fig. 6B is a top view of a bus bar of the active/passive fuse module shown in fig. 6A.

Detailed Description

The active/passive fuse module according to the present disclosure will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the active/passive fuse module are presented. It will be appreciated, however, that the active/passive fuse module may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain exemplary aspects of the active/passive fuse module to those skilled in the art.

Referring to fig. 1 and 2, a cross-sectional view of an active/passive fuse module 10 (hereinafter "fuse module 10") in accordance with an exemplary, non-limiting embodiment of the present disclosure is shown. For convenience and clarity, terms such as "front", "rear", "top", "bottom", "upper", "lower", "vertical" and "horizontal" may be used herein to describe the relative placement and orientation of the various components of the fuse module 10, each relative to the geometry and orientation of the fuse module 10 shown in fig. 1 and 2. The terminology will include the words specifically mentioned, derivatives thereof and words of similar import.

The fuse module 10 may generally include a base 12, a bus bar 14, and a Pyrotechnic Interrupter (PI) 18. The base 12 may be formed of an electrically insulating material such as plastic, polymer, ceramic, or the like. The present disclosure is not limited in this regard. The base 12 may include a cavity 20 formed in a top surface thereof.

The bus bar 14 may be formed from a single piece or length of conductive material (e.g., stamped from a single piece of copper or the like) and may include a fuse element 22 and first and second terminal portions 26a, 26b extending from opposite ends of the fuse element 22. Bus bar 14 may be disposed in a horizontal orientation on a top surface of base 12 with fuse element 22 extending over cavity 20. The first terminal portion 26a and the second terminal portion 26b may extend beyond the sides of the base 12 or beyond the sides of the base 12 for facilitating connection of the fuse module 10 within a circuit.

The fuse element 22 may be configured to melt, decompose, or otherwise open if the current flowing through the bus bar 14 exceeds a predetermined threshold or "current rating" of the fuse module 10. In various examples, the fuse element 22 may include perforations, slots, thinned or narrowed segments, and/or various other features for making the fuse element 22 easier to melt or break than other portions of the bus bar 14. In a non-limiting example, the fuse element 22 may be configured to have a current rating in a range between 30 amps and 1000 amps. The present disclosure is not limited in this regard.

PI 18 may include a housing 36 having a mounting flange 38 protruding from a lower portion thereof. The housing 36 may be disposed over the base 12 with mechanical fasteners 40a, 40b extending through the mounting flange 38 and into the base 12, the mechanical fasteners 40a, 40b being used to fasten the components together in a vertically stacked relationship. The housing 36 may include a hollow, vertically oriented shaft 43 extending therethrough. The shaft 43 may have an open bottom end located directly above the fuse element 22 and the cavity 20.

The housing 36 may include a movable piston or vane 42 (hereinafter "piston 42") disposed within a hollow shaft 43 above the cavity 20 of the base 12. The housing 36 may further include a first pyrotechnic igniter 44a disposed within the shaft 43 above the piston 42. The first pyrotechnic igniter 44a may be coupled to a controller 45 (e.g., an airbag control unit of an automobile, a battery management system, etc.). Upon the occurrence of a predefined event, such as a car crash (i.e., if the fuse module 10 is implemented in a car), the controller 45 may send an activation signal to the pyrotechnic igniter 44a, causing the pyrotechnic igniter 44 to be detonated. The resulting increase in pressure within the shaft 43 rapidly forces the piston 42 downwardly within the shaft 43 through the fuse element 22 in the bus bar 14, as shown in fig. 2. The current flow through bus bar 14 is thus interrupted and plunger 42 (which may be formed of a dielectric material) may provide an electrically insulating barrier between the separated ends of fuse element 22 to prevent arcing therebetween.

The manner in which the pyrotechnic initiator 44b is triggered (i.e., the transmission of a start signal to the pyrotechnic initiator 44b via the controller 45 upon the occurrence of a collision) described above may be referred to as "external triggering" of the pyrotechnic initiator 44 b. In various embodiments, the fuse module 10 may additionally or alternatively include an "arc strike" capability, wherein a second pyrotechnic igniter 44b may be disposed within the shaft 43 adjacent to the first pyrotechnic igniter 44 a. A pair of leads 52a, 52b may extend from the second pyrotechnic igniter 44b to the first and second terminal portions 26a, 26b, respectively. In various embodiments, leads 52a, 52b may extend through/past shaft 43 below piston 42. When the fuse element 22 melts (e.g., upon occurrence of an over-current condition), the voltage across the separated first and second terminal portions 26a, 26b may generate sufficient current in the leads 52a, 52b to cause the second pyrotechnic igniter 44b to be detonated. The resulting increase in pressure within shaft 43 rapidly forces piston 42 downwardly within shaft 43 through fuse element 22 in bus bar 14 (as described above and shown in fig. 2). Additionally, the plunger 42 cuts off the leads 52a, 52b to eliminate any potential alternative current path between the first terminal portion 26a and the second terminal portion 26b.

The above-described configuration is not intended to be limiting, and it is contemplated that leads 52a, 52b may be severed at various locations other than within shaft 43 and by structures other than piston 42. For example, instead of extending through shaft 43, leads 52a, 52b may extend through cavity 20 or elsewhere adjacent shaft 43. In various embodiments, the leads 52a, 52b may be located outside the path of the piston 42 or away from the path of the piston 42, and, instead of being directly severed by the piston 42, the leads 52a, 52b may be severed by a handle or protrusion extending from the piston 42 or by an electrical/mechanical structure or device that may be triggered by movement of the piston 42. The present disclosure is not limited in this regard.

Various additional or alternative devices, configurations, and/or arrangements for ensuring electrical isolation between the first terminal portion 26a and the second terminal portion 26b after detonation of the second pyrotechnic igniter 44b may be implemented without departing from the scope of the disclosure.

As the fuse element 22 begins to separate (e.g., melt) before the pyrotechnic igniter 44b fires and drives the plunger 42, the fuse element 22 is weakened (e.g., partially melted) before the plunger 42 is driven therethrough, making it easier for the plunger 42 to sever the fuse element 22. Thus, the fuse element 22 may be thicker/larger (and thus be able to handle higher currents) than the fuse element 22 may have if the piston 42 were required to pass through an undamaged portion of the bus bar 14 (i.e., a portion of the bus bar 14 other than the partially melted fuse element 22) as in a conventional fuse module incorporating a pyrotechnic igniter.

Although the fuse module 10 described above includes a first pyrotechnic igniter 44a coupled to the controller 45 and a second pyrotechnic igniter 44b coupled to the first and second terminal portions 26a, 26b of the bus bar 14, respectively, embodiments of the present disclosure are contemplated in which the first pyrotechnic igniter 44a and the controller 45 are omitted, and in which the fuse module 10 includes only a single pyrotechnic igniter connected to the bus bar 14 and configured to be detonated upon separation of the fuse element 22 (as described above with respect to the second pyrotechnic igniter 44 b).

Referring to fig. 3, an embodiment of the present disclosure is contemplated in which a positive temperature coefficient (positive temperature coefficient, PTC) element 60 may be connected in parallel with the fuse module 10. The PTC element 60 may be formed of any type of PTC material (e.g., polymeric PTC material, ceramic PTC material, etc.) formulated to have an electrical resistance that increases as the temperature of the PTC element 60 increases. In particular, the PTC element 60 may have a predetermined "trip temperature" above which the resistance of the PTC element 60 increases rapidly and sharply (e.g., in a non-linear manner) so as to substantially block current therethrough. The PTC element 60 may have a resistance that is greater than the resistance of the fuse element 22 over its normal operating temperature range (i.e., below its trip temperature).

During normal operation of the fuse module 10, current may flow through the bus bar 14 between the first terminal portion 26a and the second terminal portion 26 b. Upon an over-current condition, in which the current flowing through the fuse module 10 exceeds the current rating of the fuse element 22, the fuse element 22 melts or otherwise separates. The current may then be split to flow through the only alternative path available, namely through PTC element 60. As current may flow through this alternative path, potential cannot build up between the separated ends of the melted fuse element 22, thereby precluding the formation and propagation of an arc therebetween.

Referring to fig. 4, another embodiment of the present disclosure is contemplated in which a current sensing module 70 (e.g., a current sensor having a microprocessor) may be connected to one of the terminal portions 26a, 26b of the bus bar 14 and to the pyrotechnic igniter 44a of the PI 18. The current sensing module 70 may be configured to measure the current in the bus bar 14 and, upon detecting a current above a predefined threshold, may send an activation signal to the pyrotechnic igniter 44a to detonate the pyrotechnic igniter 44a and destroy the fuse element 22 as described above. The current sensing module 70 may be programmed to send the start signal immediately or after a desired, predetermined amount of time (e.g., 10 milliseconds) and in response to detecting a desired, predetermined amount of current in the bus bar 14. In various embodiments, the current sensing module 70 may also be connected to the controller 45, and the current sensing module 70 may be configured to send an activation signal to the pyrotechnic igniter 44a only if certain predetermined conditions are met. For example, the current sensing module 70 may be configured to send an activation signal to the pyrotechnic igniter 44a if the current sensing module 70 detects more than a predetermined amount of current in the bus bar 14 and if the controller 45 provides an indication of a collision to the current sensing module 70. The present disclosure is not limited in this regard.

Referring to fig. 5A, another embodiment of the present disclosure is contemplated in which the fuse element 22 of the bus bar 14 may be mechanically weakened to allow the plunger 42 to more easily break through the fuse element 22 (various components of the fuse module 10 have been omitted from fig. 5A for clarity, such as leads 52a, 52 b). In particular, the fuse element 22 may comprise a plurality of weak points, wherein the geometry of the weak points corresponds to the geometry of the piston 22. For example, referring to the top view of the bus bar 14 shown in fig. 5B, the weak points may be a plurality of perforations 80 formed in the fuse element 22, wherein the perforations are arranged in a generally circular pattern. Returning to fig. 5A, the piston 42 may have a concave bottom surface 82 defining a circular bottom edge 84, the circular bottom edge 84 being coaxial with and substantially circumferentially equal to the circular pattern defined by the perforations 80. Thus, when the plunger 42 is deployed and engages the fusible element 22, the bottom edge 84 can easily pierce the narrow portion of the fusible element 22 bridging the perforations 80, ensuring complete separation and breakthrough of the fuse element 22. For example, the piston 42 and bus bar 14 shown in fig. 5A and 5B may be implemented in any of the fuse module embodiments shown in fig. 1-4.

Referring to fig. 6A, another embodiment of the present disclosure is contemplated in which the fuse element 22 in the bus bar 14 may be mechanically weakened to allow the plunger 42 to easily break through the fuse element 22 (various components of the fuse module 10 have been omitted in fig. 6A for clarity, such as leads 52a, 52 b). In particular, the fuse element 22 may comprise a plurality of weak points, wherein the geometry of the weak points corresponds to the geometry of the piston 22. For example, referring to the top view of the bus bar 14 shown in fig. 6B, the weak points may be a plurality of perforations 90 formed in the fuse element 22, wherein the perforations are arranged in a linear pattern. Returning to fig. 6A, the piston 42 may have an angled bottom surface 92 defining a linear bottom edge 94, the linear bottom edge 94 being parallel to and aligned with the linear pattern defined by the perforations 90. Thus, when the plunger 42 is deployed and engages the fusible element 22, the bottom edge 94 can easily pierce the narrow portion of the fusible element 22 bridging the perforation 90, ensuring complete separation and breakthrough of the fuse element 22. For example, the piston 42 and bus bar 14 shown in fig. 6A and 6B may be implemented in any of the fuse module embodiments shown in fig. 1-4.

The above-described shapes, geometries, and configurations of the corresponding points of weakness in the piston 42 and fuse element 22 are provided by way of example only and may be varied without departing from the scope of the present disclosure. Further, the perforations 80 and 90 described above are merely examples of weak points that may be formed in the fuse element 22. In various embodiments, the weak points may additionally or alternatively include any type of void or recess that extends partially or entirely through the fuse element 22. These include, but are not limited to, various types of grooves, notches, indentations, cavities, valleys, pits, and the like.

In view of the foregoing, it will be appreciated that the active/passive fuse module of the present disclosure facilitates implementation of both passive and active circuit protection elements (e.g., conventional fuse elements and pyrotechnic interrupters) in a single, compact, space-saving size specification, which facilitates easy installation for a variety of applications.

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

Although the present disclosure has reference to certain embodiments, many modifications, alterations and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the disclosure not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims and equivalents thereof.

Claims

1. An active/passive fuse module comprising:

an electrically insulating base;

A bus bar disposed on a top surface of the base and including a fuse element extending over a cavity formed in the top surface of the base and having a plurality of weak points formed therein, and first and second terminal portions extending from opposite ends of the fuse element;

A Pyrotechnic Interrupter (PI) disposed above the base, the PI comprising:

A piston disposed within the shaft above the fuse element, the piston having an edge with a geometry corresponding to a geometry of a pattern defined by the weak points in the fuse element;

a first pyrotechnic igniter coupled to a controller, the first pyrotechnic igniter configured to detonate and force the piston through the fuse element upon receipt of an activation signal from the controller; and

A second pyrotechnic igniter coupled to the bus bar by a pair of leads, the second pyrotechnic igniter configured to detonate and force the piston through the fuse element upon an increase in voltage across the leads.

2. The active/passive fuse module of claim 1, wherein the lead is configured to be severed upon detonation of the first pyrotechnic igniter or upon detonation of the second pyrotechnic igniter.

3. The active/passive fuse module of claim 2 wherein the leads extend through the shaft and across the path of the piston.

4. The active/passive fuse module of claim 1, further comprising a positive temperature coefficient element connected to the bus bar in electrical parallel with the fuse element.

5. The active/passive fuse module of claim 4 wherein said positive temperature coefficient element has a resistance greater than a resistance of said fuse element over a normal operating temperature range.

6. The active/passive fuse module of claim 1 wherein the controller is adapted to send an activation signal to the first pyrotechnic igniter upon the occurrence of a predefined event.

7. The active/passive fuse module of claim 1 wherein the plunger is formed of an electrically insulating material.

8. The active/passive fuse module of claim 1 wherein the first and second pyrotechnic igniters are disposed in side-by-side relationship within the shaft.

9. An active/passive fuse module comprising:

an electrically insulating base;

A Pyrotechnic Interrupter (PI) disposed above the base, the PI comprising:

a current sensing module connected to the bus bar and configured to measure a current flowing through the bus bar; and

A pyrotechnic igniter coupled to the controller and to the current sensing module, wherein the pyrotechnic igniter is configured to detonate and force the piston through the fuse element upon receipt of an activation signal from at least one of the controller and the sensing module.

10. The active/passive fuse module of claim 9, wherein the current sensing module is configured to send an activation signal to the pyrotechnic igniter if the current flowing through the bus exceeds a predefined threshold.

11. The active/passive fuse module of claim 10, wherein the current sensing module is configured to send an activation signal to the pyrotechnic igniter if the current flowing through the bus exceeds a predefined threshold and the controller detects the occurrence of a predefined event.

12. The active/passive fuse module of claim 9, further comprising a positive temperature coefficient element connected to the bus bar in electrical parallel with the fuse element.

13. The active/passive fuse module of claim 12 wherein the positive temperature coefficient element has a resistance greater than a resistance of the fuse element over a normal operating temperature range.

14. The active/passive fuse module of claim 9 wherein the controller is adapted to send an activation signal to the pyrotechnic igniter upon the occurrence of a predefined event.

15. The active/passive fuse module of claim 9 wherein the plunger is formed of an electrically insulating material.

16. A fuse module, comprising:

an electrically insulating base;

A Pyrotechnic Interrupter (PI) disposed above the base, the PI comprising:

A piston disposed within the shaft above the fuse element, the piston having an edge with a geometry corresponding to a geometry of a pattern defined by the weak points in the fuse element; and

A pyrotechnic igniter coupled to the bus bar by a pair of leads is configured to detonate and force the piston through the fuse element upon an increase in voltage across the leads.

17. The fuse module of claim 16, wherein the lead is configured to be severed upon detonation of the pyrotechnic igniter.