WO2011157230A1

WO2011157230A1 - Large-current alloy type temperature fuse

Info

Publication number: WO2011157230A1
Application number: PCT/CN2011/075924
Authority: WO
Inventors: 徐忠厚; 许由生; 江鸿盛
Original assignee: Xu Zhonghou; Xu Yousheng; Jiang Hongsheng
Priority date: 2010-06-18
Filing date: 2011-06-20
Publication date: 2011-12-22
Also published as: CN202094065U

Abstract

A large-current alloy type temperature fuse for overheating protecting of a device with a large-current characteristic is disclosed. In the alloy type temperature fuse, a plurality of low melting point alloy wires (13) are welded and connected in parallel between two metal electrodes (11a, 11b) with favorable weldability. The metal electrodes are separated by a part (18) formed of an insulating material, and are provided with extension parts (11aa, 11bb) extending out of a shell (15), enabling a close thermal coupling between the large-current alloy type temperature fuse and the thermally protected device. Further, a fluxing agent material (14) is provided around each low melting point alloy wire, so that each low melting point alloy wire can be quickly and completely retracted to the electrodes after heated and melted, and thereby a large current is switched off safely.

Description

A high current alloy type thermal fuse

Technical field

The present invention relates to a high-current alloy-type temperature fuse, particularly for protection against overheating of a device having a large current characteristic such as a power storage battery.

Background technique

Since the beginning of the 21st century, the global automotive industry has faced the dual pressures of energy and environmental issues. The development and use of new batteries has provided a new type of automotive energy for the development of the automotive industry. During the use of the battery, excessive discharge current or accidental events often cause the battery to heat up or explode. In the past, the overheat protection mode of the power battery mainly used the current limiting type fuse, but could not effectively solve the contradiction between the working current and the fault current; or use an electronic circuit with a temperature sensor to drive the relay or the circuit breaker to cut off the discharge current of the battery, for example U.S. Patent No. 5,070,427 discloses a thermal switch for battery protection (Thermal Switch for Battery Protection); US 5357184 discloses a Fuse System for a Multiple Battery Charger; US 5879832 discloses a current interrupter for electrochemical cells (Current Interrupter for Electrochemical An overshoot protection device and method for lithium-based rechargeable batteries is disclosed in US Pat. No. 6,608,470 (Overcharge Protection Device) And Methods for Lithium Rechargeable Batteries); and the US patent number is US 5097247 discloses a heat actuated fuse device with solder joints (Heat Actuated Fuse Apparatus with solder Link), these battery protection measures can protect the battery's charge and discharge safety, but the protection measures are more complicated.

As is known, alloy-type thermal fuses are sensitive to temperature changes. Their actions are mainly responsive to the temperature of the protected device, but they are not sensitive to current. When the current flowing through the rated operating current greatly exceeds the rated operating current, the alloy-type thermal fuse will also blow. However, the response speed is far less than the effect of the current limiting fuse. If there is an alloy type thermal fuse that can withstand the discharge current of the battery and can sense the temperature rise of the battery, the thermal protection measures of the battery can be simplified. However, current current temperature fuses have a relatively low current carrying capacity and cannot carry large discharge currents of the power battery.

Summary of the invention

The purpose of the invention is to overcome the shortcomings of the existing thermal fuses that cannot protect the large-capacity power storage battery, and provide an alloy-type thermal fuse with a large current as a thermal protection of the power storage battery to protect the battery from charge and discharge. Technical measures are simplified. It also provides easy overheat protection for devices with high current characteristics.

The present invention provides an alloy type temperature insurance having a large current, and more particularly to a thermal fuse for thermal protection of a device having a large current characteristic such as a large-capacity power storage battery. Since the alloy type thermal fuse is operated in series with the battery, the alloy type thermal fuse must carry the high discharge current of the power battery. In order to solve this problem, a plurality of (including two) low melting point alloy wires are connected in parallel, and a flux material is disposed around each of the low melting point alloy wires, so that each low melting point alloy wire can promote each after being heated and melted. The root low melting point alloy wire is quickly and completely retracted back to the electrode. Using this method, a high-current alloy type thermal fuse can be manufactured.

The ampere-capacity alloy type thermal fuse has the following structure: there are two columnar metal electrodes with good solderability, and in order to separate the metal electrode columns by a predetermined distance, one electrode is fixed by an insulating material; A plurality of low melting point alloy wires are welded in parallel between the two column electrodes, and a fluxing material is disposed around each of the low melting point alloy wires, thereby forming a plurality of alloy type temperature fuse units, and a An outer casing made of engineering plastics, ceramic materials, metal materials or a combination of the above materials. Two metal electrode extensions extend out of the outer casing through the epoxy of the sealed outer casing.

The composition of the alloy type thermal fuse of such an amperage capacity may also be such that two sheet metal electrodes having good solderability have through holes for soldering low melting point alloy wires on the two sheet metal electrodes. Moreover, the positions of the through holes on the two chip electrodes are completely consistent; in order to separate the metal electrodes by a predetermined distance, one of the two thermally conductive metal electrodes is supported by an insulating material or more than one insulating post; The melting point alloy wire is provided with a material containing a fluxing agent around each low melting point alloy wire, thus forming a plurality of alloy type temperature fuse units, and the distribution thereof can be arranged in parallel between the two electrodes. a flat surface, a curved surface, a circular surface or a circular surface; and an outer casing made of an engineering plastic, a ceramic material, a metal material or a combination of the above materials; the two metal electrodes protrude out of the outer casing through the epoxy of the sealed outer casing. The outer casing and the electrodes extending out of the outer casing allow the high current alloy type thermal fuse to be thermally coupled between the protective devices.

Even if the diameter of the low melting point alloy wire of the ordinary alloy type thermal fuse is increased, the volume is too large, which increases the difficulty of shrinkage and creep of the molten alloy under the interface tension between the alloy and the fluxing material, even There is a serious danger that the current cannot be safely cut off, and it is not possible to quickly respond to the protected heating temperature, so it is difficult to obtain a high-current temperature fuse with excellent protection effect. The invention adopts a method in which a plurality of alloy wires are connected in parallel, which can realize both a large current and a rapid response to overheating and disconnection; it is now possible to manufacture an operating current exceeding A 40 amp alloy-type thermal fuse can also be used to produce an alloy-type thermal fuse with a pulse current of 8/20 microseconds greater than 20kA, and even a pulse current with an 8/20 microsecond waveform that is greater than 100KA. The temperature fuse can be used to cut off the fault current of the power supply unit and the surge protection device (SPD).

DRAWINGS

1 is a front cross-sectional view of Embodiment 1 of a method in accordance with the present invention.

Figure 2 is a side cross-sectional view of Embodiment 1 of the method in accordance with the present invention.

Figure 3 is a perspective exploded view of Example 1 of the method in accordance with the present invention.

Figure 4 is a front cross-sectional view of Embodiment 2 of the method in accordance with the present invention.

Figure 5 is a side cross-sectional view of Embodiment 2 of the method in accordance with the present invention.

Figure 6 is a perspective exploded view of Example 2 of the method in accordance with the present invention.

detailed description

The present invention will be further described with reference to the accompanying drawings, FIG. 2, FIG. 2 and FIG. 3 and the specific embodiments, in which the present invention is described for the purpose of illustrating the preferred embodiments of the present invention The above purpose. 1, FIG. 2 and FIG. 3 are respectively a front cross-sectional view, a side cross-sectional view and a perspective anatomical view of a high current alloy type thermal fuse according to a preferred embodiment of the present invention. In the described embodiment, the high current alloy type thermal fuse includes a housing 15 in which is assembled an assembly of the following components: two conductive and thermally

conductive metal electrodes

11a and 11b, In an embodiment, the conductive thermally conductive metal electrode is cylindrical, and the two conductive and thermally

conductive metal electrodes

11a and 11b are supported by the insulating plate 18 to ensure that the two

metal electrodes

11a and 11b are substantially parallel, two metals. The electrodes have extension portions 11aa and 11bb as outer lead wires respectively; two low-melting-point alloy wires 13 are welded between the two

metal electrodes

11a and 11b, thereby forming an alloy type temperature fuse body; The distribution mode; the low melting point alloy wire will melt at a predetermined melting temperature; the fluxing material 14 is disposed around the low melting point alloy wire, and when the external heat is transferred to the low melting point alloy wire, the temperature reaches or exceeds the predetermined condition of the alloy wire. At the melting temperature, all the alloy wires will melt and break; the fluxing material 14 not only promotes the melting of the alloy wire, but also promotes the alloy wire to two. Metal electrode retracted. The alloy type thermal fuse body is assembled into the outer casing 15 and sealed with an epoxy resin 12, and the two metal electrodes respectively have extension portions 11aa and 11bb exposed through the epoxy resin, which is a lead wire for connecting an external circuit. It is also a connector that completes a tight thermal coupling with the protected device. The number of low melting point alloy wires depends on the expected current in the circuit.

Embodiment 2, which is further described below with reference to FIG. 4, FIG. 5, and FIG. 6 of another specific embodiment, wherein FIG. 4, FIG. 5 and FIG. 6 are respectively the specific implementation. A front cross-sectional view, a side cross-sectional view, and a perspective anatomical view of the high current alloy type thermal fuse of Example 2, in the described embodiment, the high current alloy type thermal fuse includes a housing 15 in the housing 15 It is equipped with an assembly consisting of two conductive and thermally

conductive metal electrodes

11a and 11b. In this embodiment, the electrically and thermally conductive metal electrodes are plate-shaped, and have a plurality of arrays arranged in an array on the two metal electrodes. Through holes, and the positions of the through holes on the two electrodes are completely consistent, and a plurality of low melting

point alloy wires

13a, 13b pass through the through holes, and the two ends of the alloy wire are respectively soldered on the metal electrodes, which is in the embodiment. 8 low melting point alloy wires, but the invention is not limited to 8 pieces, the number of low melting point alloy wires can be adjusted as needed to obtain alloy type temperature fuses with different amperage capacities; in the circumference of each low melting point alloy wire The fuse 14 is provided, and the extension portions 11aa and 11bb of the metal electrodes forming the external lead wires are separated by an insulating plate 18, on the extension portions 11aa and 11bb and the insulating plate 18 of the thermally conductive conductive metal electrodes forming the external lead wires, A hole 17 for assembling a large current alloy type thermal fuse to an external circuit is provided. The alloy type thermal fuse body is assembled into the outer casing 15 and sealed with epoxy resin 12 to form a complete high-current alloy type thermal fuse.

Industrial applicability

The invention adopts a method in which a plurality of alloy wires are connected in parallel, which can realize both a large current and a rapid response to overheating and disconnection; it is now possible to manufacture an operating current exceeding A 40 amp alloy-type thermal fuse can also be used to produce an alloy-type thermal fuse with a pulse current of 8/20 microseconds greater than 20kA, and even a pulse current with an 8/20 microsecond waveform that is greater than 100KA. The temperature fuse can be used to cut off the fault current of the power supply unit and the surge protection device (SPD).

Claims

A high current alloy type thermal fuse comprising a casing, two metal electrodes, a plurality of low melting point alloy wires, a fluxing aid; one or more insulating pillars for sealing the epoxy of the mouth of the casing; Characterized in that the plurality of low-melting-point alloy wires are welded to two conductive and thermally conductive metal electrodes to form a parallel connection; the conductive and thermally conductive metal electrodes are separated by the pillars of the insulating material; An alloy wire is surrounded by the fluxing agent; the above-mentioned conductive and thermally conductive metal electrode, the plurality of (including two) low melting point alloy wires, a pillar composed of the insulating material, and the The fuse-containing material constitutes an assembly, the component is placed in the outer casing, and the opening of the outer casing is sealed with epoxy resin so that the extension of the two metal electrodes protrudes outside the outer casing, and the outer casing extends out to the outer casing The extension of the outer metal electrode provides a close thermal coupling between the high current alloy type thermal fuse and the thermally protected device.
A high current alloy type thermal fuse according to claim 1, wherein said low melting point alloy wire has a circular or polygonal cross section, and the alloy wire is arranged in parallel in a plane and a circle between the two electrodes. Shaped or toroidal.
A high current alloy type thermal fuse according to claim 1, wherein the partition member separating the two electrically and thermally conductive metal electrodes is a flat plate of an insulating material.
A high current alloy type thermal fuse according to claim 1, wherein said low melting point alloy wire has a predetermined melting temperature in the range of 70-183 Between °C, an alloy of lead-free, cadmium-free and mercury-free metal materials.
A high current alloy type thermal fuse according to claim 1, wherein said two electrically and thermally conductive metal electrodes are columnar or sheet-shaped.
A high current alloy type thermal fuse according to claim 1, wherein said two electrically and thermally conductive metal electrodes are a pair of L-shaped metal plate electrodes.