Protection device with u-shaped fuse element

Provided herein are protection devices having U-shaped fuse elements. In some embodiments, a protection device may include a housing defining a cavity, and a fuse element within the cavity. The fuse element may include a first component and a second component separated by a barrier, and wherein the first and second components are joined at a fusible bridge.

FIELD OF THE DISCLOSURE

The disclosure relates generally to circuit protection devices, more particularly, to a protection device with a U-shaped fuse element.

BACKGROUND OF THE DISCLOSURE

Fuses are commonly used as circuit protection devices. Fuses can provide electrical connections between sources of electrical power and circuit components to be protected. High-voltage, current-limiting fuses are used in a variety of applications including, for example, Electric Vehicles (EVs) and Hybrid-Electric Vehicles (HEVs). EV systems typically use much higher voltages and currents than non-EV automotive systems. Bus voltages for EV systems can be in the range of 600 volts DC or AC, and currents can be in the range of 300 amps. These high-voltage applications therefore require fuses capable of handling the increased energy and arcing associated with an opening of a fuse element within the fuse used for such applications.

Capable EV fuse products currently existing have limited mounting and wiring options. The assortment of shapes of overcurrent protection equipment and difficulties in wiring tends to result in inefficient use of space in limited areas. As space becomes a premium in a competitive EV industry, a more efficient overcurrent protection device is desired.

SUMMARY

In some embodiments, a protection device may include a housing defining a cavity, and a fuse element within the cavity. The fuse element may include a first component and a second component separated by a barrier, and wherein the first and second components are joined at a bridge.

In some embodiments, a fuse assembly may include a housing defining a cavity, and a fuse element within the cavity, wherein the fuse element includes a first component extending parallel to a second component, wherein the first and second components are joined at a bridge, and wherein the first and second components are separated by a barrier.

In some embodiments, a protection device may include a housing defining a cavity, and a fuse element within the cavity, wherein the fuse element includes a first component and a second component separated by a barrier and joined at a fusible bridge, and wherein the fuse element has an inverted U-shape.

The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict typical embodiments of the disclosure, and therefore should not be considered as limiting in scope. In the drawings, like numbering represents like elements.

DETAILED DESCRIPTION

Fuse apparatuses and assemblies in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the system and method are shown. The fuse apparatuses and assemblies, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the system and method to those skilled in the art.

As mentioned above, EV fuses are a relatively new type of fuse to the automotive market within the last decade or so. Historically, these fuses have roots in industrial fuse design and have been slowly progressing to a more automotive-friendly design as volumes ramp up. The industrial design is typically very limiting in attachment into the application, overall fuse construction/appearance, and robustness. This disclosure provides a more automotive-friendly design, e.g., in shape/construction, performance, and features.

Although non-limiting, embodiments of the present disclosure may be applicable to fuses operating at a minimum of 500 VDC and including, or even surpassing, 1000 VDC. Current range may be even more broad, but typically includes ratings from 100 A to 500 A.

In some embodiments, the overall construction of the fuse element takes on an inverted u-shape. During an arc event, when there is an abrupt change in magnitude of current flow, the arc is forced outward and away from the two current paths of the u-shaped element due to electromagnetic forces (B-forces). Advantageously, by forcing the arc outward, the arc is lengthened and pushed away from metal of the fuse, which would otherwise feed the arc and, thus, more likely to be extinguished quickly.

The disclosure also considers the fact that the closer together the current paths are, the higher this B-force is. As such, embodiments herein may provide a barrier to separate the two paths the u-shaped element and provide insulation and additional arc suppression. Utilizing a highly endothermic material, e.g., melamine or Polyamide 46 (PA46), can also help extinguish the arc due to the close proximity and outgassing or endothermic effects. Utilizing this material in other areas of the fuse construction (e.g., entire body, etc.) may also help improve the arcing performance of the fuse, possibly allowing for the elimination of sand from high voltage fuses.

An additional performance method for quenching the arc according to embodiments of the present disclosure is to use a varied volume arc chamber. For example, as the arc consumes the current paths of the fuse element, the B-force forces the arc into a larger volume area, which reduces the energy of the arc not only by lengthening it, but by reducing the pressure. This is especially advantageous when designing a high voltage fuse without a filler material (e.g., sand).

Furthermore, in some embodiments of the disclosure, splitter plates may be added to the device, wherein the arc can be cooled down by adding non-current-carrying mass to the arc path. Advantageously, this can improve the arcing performance with sand or potentially allow for elimination of the sand entirely. Still furthermore, in some embodiments, packaging options may also be varied. For example, plug-in terminals can be utilized due to the construction of the bottom fuse section. In other embodiments, terminals can be formed and stamped with a hole for bolt-down applications. In still other embodiments, the terminals can be formed along the sides of the fuse body to work with soldered PCB applications or clamp-type connections. Similar to 0HEV/10EV, this type of construction can accept custom terminals that can be soldered to terminal stubs.

Still furthermore, another aspect of this disclosure is the addition of armor to enclose the fuse. Wrapping the high arc quenching material in a stronger material may allow more strength, thus keeping pressure inside of the fuse from escaping. This advantageously allows for a smaller footprint and reduces the use of arc-quenching material, which may be expensive.

Referring toFIG. 1, an exemplary embodiment of a fuse apparatus/assembly/device (hereinafter, “device”)100in accordance with the present disclosure is shown. The exemplary device100may include a housing102defining an internal cavity104. Although not limited to any particular shape or configuration, the housing102may include a base wall106, a top wall108, and a set of sidewalls110. In some embodiments, the various components of the housing102may be made of an insulating material, such as an insulating plastic, e.g., nylon, glass-filled nylon, polyester and polycarbonate. In various embodiments, the base wall106, the top wall108, and the sidewalls110can be made of the same or different materials.

The cavity104may include one or more circuit protection devices, e.g., fuses114, disposed therein. The fuse114may include a fuse element116within the cavity104, the fuse element116being formed from or comprised of any material having desirable electrically conductive properties. In certain embodiments, the fuse element116can be nickel, copper, tin, or an alloy or mixture comprising nickel, copper, silver, gold, or tin, or any combination thereof. In certain embodiments, the fuse element116may have an approximate thickness of between 5 and 20 mils (a mil being a thousandth of an inch).

The fuse element116may include a first component118and a second component120separated by a barrier122. Although non-limiting, the first and second components118,120generally extend parallel to one another, forming an inverted U-shape. The first and second components118,120may be joined at a bridge128. In some embodiments, the bridge128may include one or more weakened or thinned segments separated by perforations to form a set of fusible links. During an overcurrent event, the fusible links fail to prevent current from passing between the first and second components118,120. In some embodiments, the first and second components118,120extend parallel to corresponding exterior surfaces of the barrier122. In some embodiments, the first and second components118,120may be in direct contact with the barrier122. Said another way, the fuse element116may wrap around the barrier122.

As further shown, a first terminal130may be connected to the first component118and a second terminal132may be connected to the second component120. In this embodiment, the first and second terminals130,132extend outside of the housing102, through the base wall106. As illustrated, the free ends of the first and second terminals130,132may be formed as blades for connection as a plug-in fuse to the other electrical components.

In some embodiments, the cavity104may be filled with an arc suppressant material, such as silica, silicone, sand, or any combination thereof. An opening through the housing102may allow the cavity104to be filled with the arc suppressant material. Although non-limiting, the hole may be centered in the top wall108so that the arc suppressant material may evenly fill the cavity104.

As shown, the barrier122may extend between the first and second components118,120of the fuse element116. The barrier122and the first and second components118,120may extend perpendicular to the base wall106. In exemplary embodiments, the barrier122may be constructed from a high outgassing or endothermic materials. The barrier122and the base wall106may be the same material. During use, the barrier122is an arc barrier generally formed according to the shape of the fuse element116.

Referring toFIG. 2, an exemplary embodiment of a fuse device (hereinafter, “device”)200in accordance with the present disclosure is shown. The device200may be the same or similar in certain aspects to the device100described above. As such, only certain aspects of the device200may hereinafter be described for the sake of brevity. The exemplary device200may include a housing202defining an internal cavity204. A u-shaped fuse element216may be disposed within the cavity204. The housing202may include a base wall206, a top wall208, and a set of side walls210.

The housing202may further include an armor layer240extending into the cavity. In some embodiments, the armor layer240may be formed along interior surfaces of the base wall206, the top wall208, and the side walls210. In other embodiments, the armor layer240may additionally, or alternatively, be formed along one or more exterior surfaces of the housing202. As shown, an interior surface242of the armor layer240may define the cavity204. In this embodiment, the cavity204takes on an inverted teardrop shape or profile. The shape of the cavity204keeps an arc volume244generally equidistant from the interior surfaces of the housing202to provide enhanced cooling and outgassing. In some embodiments, the armor layer240may be a stainless steel. In some embodiments, the cavity204may be filled with an arc suppressant material, such as silica, or sand.

Referring toFIG. 3, an exemplary embodiment of a fuse device (hereinafter, “device”)300in accordance with the present disclosure is shown. The device300may be the same or similar in certain aspects to the devices100and200described above. As such, only certain aspects of the device300may hereinafter be described for the sake of brevity. The exemplary device300may include a housing302defining an internal cavity304. A u-shaped fuse element316may be disposed within the cavity304. The housing302may include a base wall306, a top wall308, and a set of side walls310.

Extending into the cavity304may be a plurality of splitter plates348. The splitter plates348may generally extend perpendicular to the top wall308. During use, the splitter plates348split arcs into a series of smaller arcs of less voltage. The splitter plates348may be symmetrical on both sides of a centerline extending through a barrier322. The splitter plates348can be made of any ferrous material, including, but not limited to, steel. More or fewer plates than shown can be used in other implementations. Furthermore, it will be appreciated that the size of splitter plates348, and the spacing(s) between them, can be chosen depending on the particular implementation, such as based on the overall size of the device300and/or the voltage or current that is expected to occur.

In some embodiments, the housing302may further include an armor layer340formed along interior surfaces thereof. Furthermore, in some embodiments, the cavity304may be filled with an arc suppressant material, such as silica, or sand.

Referring toFIG. 4, an exemplary embodiment of a fuse device (hereinafter, “device”)400in accordance with the present disclosure is shown. The device400may be the same or similar in certain aspects to the devices100,200, and300described above. As such, only certain aspects of the device400may hereinafter be described for the sake of brevity. The exemplary device400may include a housing402defining an internal cavity404. A u-shaped fuse element416may be disposed within the cavity404. The housing402may include a base wall406, a top wall408, and a set of side walls410.

The housing402may further include an armor layer440extending towards the fuse element416. In some embodiments, the armor layer440may be formed along interior surfaces of the side walls410and the base wall406. As shown, the armor layer440is not formed along the top wall408. An interior surface442of the armor layer440may partially define the cavity404. In some embodiments, the armor layer440may be a stainless steel. In some embodiments, the cavity404may be filled with an arc suppressant material, such as silica, or sand.

It will be appreciated that various housing and terminal configurations may be possible in different embodiments. For example, as shown in device500ofFIG. 5, a first terminal530and a second terminal532extend flat along a base wall506of a housing502. In some embodiments, each of the first and second terminals530,532may include openings (not shown) to receive a fastener. As shown in device600ofFIG. 6, a first terminal630and a second terminal632extend along a base wall606and each sidewall610of a housing602. The first and second terminals530,532may be clampable.

The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure may be grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof are open-ended expressions and can be used interchangeably herein.

Furthermore, identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority, but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.

Furthermore, the terms “substantial” or “substantially,” as well as the terms “approximate” or “approximately,” can be used interchangeably in some embodiments, and can be described using any relative measures acceptable by one of ordinary skill in the art. For example, these terms can serve as a comparison to a reference parameter, to indicate a deviation capable of providing the intended function. Although non-limiting, the deviation from the reference parameter can be, for example, in an amount of less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, and so on.