CN218513652U - Thermal protection device for battery - Google Patents

Abstract

The application discloses battery thermal protection device, utilize the shell lateral part to set up the opening, it is fixed and insert from the lateral part of shell to combine action shell fragment and heat response shell fragment, and then reuse the heat-retaining element and carry out the shutoff opening, under the prerequisite of guaranteeing each component contact, there may be the gap between each component in the laminated structure as far as possible to have reduced, contact failure and the impedance change because these gaps permeate impurity to lead to have avoided, and simultaneously, give up the scheme that prior art adopted the PTC component return circuit in this application, adopt phase change material to regard as the heat-retaining material, when having avoided the PTC return circuit, have certain electric current to flow through the return circuit and the potential safety hazard that causes in the future, and the safety is improved.

Description

Thermal protection device for battery

Technical Field

The utility model relates to a thermal protection device particularly relates to a battery thermal protection device.

Background

A battery thermal protection device is a device that blocks current for protecting a battery due to an excessive temperature rise during charging and discharging of the battery, and there is an increasing demand for a thermal protection device used in a battery mounted on a portable electronic device such as a mobile phone or a notebook computer in the modern society. In particular, in recent electronic devices, the amount of current required for using the electronic devices tends to increase due to advanced functions such as signal processing and image processing, and therefore, it is necessary to use a high capacity battery and the current thereof also increases, and thus a small-sized high-current thermal temperature protector is urgently required.

Chinese utility model patent publication No. CN103999180A in the related art discloses a circuit breaker including a fixed piece having a fixed contact, a movable piece having a movable contact at a front end portion, a thermal strain element that deforms with a change in temperature, a PTC thermistor, and a resin case stacked in sequence one on another.

The following disadvantages exist in the prior art: 1. in the prior art, the structure adopts the PTC thermistor, but when the PTC loop exists, the physical contact of two end points cannot be completely cut off when the switch is turned off, and a certain current flows through the loop, so that the thermal protection device is still electrified under the condition of circuit breaking, and potential safety hazards exist; 2. the internal device in the prior art is covered after being assembled in a stacking mode, but due to the stacking structure, gaps can be left among all parts of the whole thermal protection device, moisture or dust can easily enter the gaps, corrosion of all internal elements and poor contact of contacts can be caused, and due to the existence of the gaps, the positions of the elements (particularly thermal response elements) can be easily moved, contact impedance changes can be caused, and further the failure of products can be caused.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a battery thermal protection device is particularly a safer and assemble the battery thermal protection device that the performance is more stable.

In order to achieve the above object, there is provided a thermal protection device for a battery, including: an integrated into one piece's shell, the lateral part of shell is equipped with the opening, and it: the fixed elastic sheet is provided with a fixed contact; the action elastic sheet is arranged opposite to the fixed elastic sheet, the action elastic sheet is provided with an elastic part and an action contact arranged at the front end of the elastic part, and the action contact and the fixed contact are mutually contacted through the elastic part by the action elastic sheet; the heat reaction elastic sheet is provided with a position between the fixed elastic sheet and the action elastic sheet, one end of the heat reaction elastic sheet is folded and fixed on the action elastic sheet to form a fixed part, the other end of the heat reaction elastic sheet is tightly attached to the action elastic sheet, and the heat reaction elastic sheet deforms through the change of temperature to enable the action contact of the heat reaction elastic sheet to be separated from the fixed contact; the heat storage element is wrapped around the fixing part and blocks the opening of the shell.

Further, the heat storage element is made of a solid-solid phase change material, and a resin sealing cover is arranged on the outer side of the heat storage element.

Furthermore, the action spring plate is provided with a fixed snap ring, and the fixed snap ring clamps the fixed part of the heat reaction spring plate from two sides.

Furthermore, the action spring plate is provided with a protruding part, and the protruding part is slightly contacted with the heat reaction spring plate.

Furthermore, one surface of the elastic part of the action elastic sheet, which is far away from the heat reaction elastic sheet, is provided with an upward convex stress reinforcing rib.

Further, a positioning landslide is arranged at one end, far away from the opening, in the shell.

Furthermore, the outer surface of the shell is also provided with a temperature conduction sheet, and two ends of the temperature conduction sheet extend into the shell and are respectively contacted with the heat storage element and the fixed elastic sheet.

Compared with the prior art, the beneficial effects of the utility model are that:

1. according to the heat storage device, the PTC element is omitted, the position of the heat storage element is modified, on the premise that safety is guaranteed, the heat storage element can keep the temperature and can maintain a period of time on the heat reaction elastic sheet to ensure that the cut-off current is not turned on too early, and then the heat storage element is turned on again when the ambient temperature or the battery temperature is reduced to the set return temperature (the specific numerical characteristic can be controlled according to the formula of the phase change material of the heat storage element).

2. The whole structure is improved, the stacking structure and the mounting mode of each element in the prior art are changed, gaps among parts of the whole thermal protection device are avoided, and impedance change caused by poor contact among the elements is reduced.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without inventive labor.

Fig. 1 is a schematic view of the overall structure of the thermal battery protection device of the present application;

FIG. 2 is an exploded view of the overall construction of the thermal protection device of the battery of the present application;

fig. 3 is an exploded view of the actuating spring and the thermal reaction spring of the thermal battery protection device of the present application;

fig. 4 is a bottom view of an actuating spring plate of the thermal battery protection device of the present application;

fig. 5 is a sectional view showing the overall structure of the thermal protection device for a battery according to the present application;

fig. 6 is another overall structural schematic diagram of the battery thermal protection device of the present application;

fig. 7 is a schematic view of a third overall structure of the thermal battery protection device of the present application;

the reference numbers and designations in the drawings are as follows:

the thermal storage device comprises a shell 100, an opening 110, a fixed spring 200, a fixed contact 210, an action spring 300, an elastic part 310, an action contact 320, a thermal reaction spring 400, a fixed part 410, a thermal storage element 500, a resin sealing cover 510, a fixed snap ring 330, a protruding part 340, a stress reinforcing rib 350, a temperature conduction sheet 130 and a positioning slide 120.

Detailed Description

The technical solutions in the embodiments of the present invention will be described below clearly and completely, and it should be apparent that the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-4 for explaining the battery thermal protection device of the application, as shown in fig. 1 and 2, a battery thermal protection device includes a housing 100 having an opening 110 at a side thereof, the housing 100 is made of polyphenylene sulfide, a fixing elastic sheet 200 is provided in the housing 100, the fixing elastic sheet 200 is integrally stamped, the fixing elastic sheet 200 is made of copper alloy with good conductivity, preferably, the fixing elastic sheet 200 includes, by weight, 6% to 7% of tin, 0.1% to 0.25% of phosphorus, 0.1% of zinc, and the rest of copper, the fixing elastic sheet 200 is inserted into the housing 100 from a portion of the housing 100 away from the opening 110, and one end of the fixing elastic sheet 200 outside the housing 100 is used for connecting a load in a circuit, the end of the fixed elastic sheet 200 inserted into the housing 100 is provided with a fixed contact 210 facing the housing 100, the fixed contact 210 is made of silver-nickel alloy, preferably, the silver content of the silver-nickel alloy of the fixed contact 210 is 90-85% and the nickel content is 10-15% by weight, pure silver has high electrical conductivity and thermal conductivity, low and stable contact resistance and good processability, a small amount of nickel is added, material structure grains can be greatly refined, and the mechanical strength and temperature resistance of the fixed elastic sheet are higher than those of pure silver under the condition that the contact resistance is almost the same, so that the welding resistance and arc burning resistance of the silver-nickel alloy are better, the fixed contact 210 and the fixed elastic sheet 200 are combined by adopting a hot pressing process, the copper in the fixed elastic sheet 200 and the silver in the fixed contact 210 can be well combined together, the metal property of respective materials can not be damaged after the materials are not separated easily, the installation operation is convenient, and the problems of production and performance influence and the like caused by welding (insecurity, easy separation, difficult welding, difficult production and high contact resistance) and riveting (difficult operation, poor contact and high contact resistance) and the like in the prior art are avoided.

The battery cell connector is characterized in that an action spring sheet 300 is further arranged in the shell 100, the part of the action spring sheet 300 extending into the shell 100 from the opening 110 of the shell 100 is opposite to the fixed spring sheet 200, one end of the action spring sheet 300 outside the shell 100 is used for connecting a battery cell in a circuit, one end of the action spring sheet 300 inside the shell 100 is provided with an elastic part 310 and an action contact 320 arranged at the front end of the elastic part 310, and the action spring sheet 300 enables the action contact 320 to be in contact with the fixed contact 210 through the elastic part 310. Preferably, in terms of weight percentage, the copper alloy of the action spring 300 contains 6% to 7% of tin, 0.1% to 0.25% of phosphorus, 0.1% of zinc, and the balance of copper, the fixed contact 210 is made of silver-nickel alloy, in terms of weight percentage, the silver content of the silver-nickel alloy of the fixed contact 210 is 90% to 85%, the nickel content is 10% to 15%, and the action contact 320 and the action spring 300 are combined by a hot pressing process.

The inside heat reaction spring piece 400 that still has of shell 100, heat reaction spring piece 400 is the setting of crooked form between fixed shell fragment 200 and action shell fragment 300, in the preferred condition, heat reaction spring piece 400 comprises bimetallic strip, bimetallic strip is formed by the nickel-iron metal pressfitting of the molybdenum-nickel-copper alloy of high expansion ratio and low expansion ratio, the one end of heat reaction spring piece 400 is drawn in and is fixed and form fixed part 410 on action shell fragment 300, it is preferred, be equipped with fixed buckle 330 on the action shell fragment 300, thereby fixed buckle 330 grips fixed part 410 of heat reaction spring piece 400 from both sides and fixes it, action shell fragment 300 is hugged closely to the other end of heat reaction spring piece 400, heat reaction spring piece 400 is when overheated and reach the action temperature, the crooked shape of heat reaction spring piece 400 is along with rapid motion and reverse bending, leads to action shell fragment 300's elastic part 310 to take place the bending to make its action contact 320 and fixed contact 210 break away from, if the temperature through cooling and when being less than the recovery temperature, then can the initial crooked form of heat reaction spring piece 400.

The heat storage element 500 is wrapped around the fixing portion 410, and when the thermal protection device is overheated and the actuating elastic piece 300 is separated from the fixing elastic piece 200 by the heat reactive elastic piece 400, the heat storage element 500 is reversely bent at the heat reactive elastic piece 400 for a period of time by heat storage and heat release to keep the temperature so as to ensure that the cut-off current is not restored to be turned on too early. The heat storage element 500 is preferably made of a solid-solid phase change material, and the shape of the heat storage element is matched with that of the opening 110 of the housing 100, so that when the action spring piece 300 extends into the housing 100 from the opening 110 of the housing 100, the heat storage element 500 can be used for blocking the opening 110 of the housing 100.

As shown in fig. 5, in a normal condition, the actuating contact 320 and the fixed contact 210 are in contact with each other, one end of the actuating elastic sheet 300 outside the casing 100 is used for receiving current flowing through the battery cell, and simultaneously taking out temperature generated inside the battery, and then the temperature is transmitted to a load through the actuating contact 320 and the fixed contact 210 via the fixed elastic sheet 200, when the temperature inside the battery cell or outside the product is too high (exceeding the rated temperature of the product) or the current flowing through the contacts is too high (causing the temperature of the fixed contact 210 and the actuating contact 320 to be too high), heat is conducted to the heat reactive elastic sheet 400 through the fixing portion 410, when the heat reactive elastic sheet 400 is overheated to reach an actuating temperature, the bent shape of the heat reactive elastic sheet 400 is reversely bent along with rapid movement, causing the elastic portion 310 of the actuating elastic sheet 300 to bend, so as to push the actuating contact 320 to be out of contact with the fixed contact 210, at this time, the current transmitted from the battery cell to the load will be forcibly cut off to play a role of safety protection, at this time, the heat storage element 500 can maintain a temperature capable of reversely bending for a period of time in the heat reactive spring 400 to ensure that the cut-off current does not return to the on state too early (about 1-2 minutes), when the battery cell or the external temperature drops to the recovery temperature at the design time (usually below 50 ℃), the heat reactive spring 400 will quickly return to the initial bent state due to the temperature being lower than the recovery temperature, at this time, the circuit will return to the on state, as can be seen from the above-mentioned embodiment, unlike the prior art that a laminated structure is adopted, the opening 110 is provided at the side of the casing 100, the actuating spring 300 is combined with the heat reactive spring 400 and inserted from the side of the casing 100, furthermore, the opening 110 is sealed by the heat storage element 500, on the premise of ensuring the contact of each element, gaps possibly existing among the elements in the laminated structure are reduced as much as possible, poor contact and impedance change caused by the fact that impurities permeate into the gaps are avoided, meanwhile, the scheme that a PTC element loop is adopted in the prior art is abandoned, a phase-change material is adopted as the heat storage material, the potential safety hazard caused by the fact that certain current flows through the loop when the PTC loop exists is avoided, and the safety is improved.

In the above embodiment, as shown in fig. 4, the protrusion 340 is disposed on the operation spring 300, the protrusion 340 is in close contact with the heat reaction spring 400, the protrusion 340 can further enhance the bending degree of the heat reaction spring 400, so that the heat reaction spring 400 can better drive the elasticity of the operation spring 300 not to bend when being reversely bent due to overheating, and in addition, the elastic portion 310 of the operation spring 300 is disposed with the stress reinforcing rib 350 protruding upward, specifically, the stress reinforcing rib 350 is disposed on a surface deviating from the heat reaction spring 400, the stress reinforcing rib 350 may not apply a stress facing the fixing spring 200 to the elasticity, so that the operation spring 300 may have an initial bending of the phase fixing spring 200, and thus the contact between the fixing contact 210 and the operation spring 300 may be tighter.

In the above embodiment, as shown in fig. 5, one end of the housing 100 far from the opening 110 is provided with a positioning slope 120, and the end of the positioning slope 120 is a fixed contact 210 on the fixed elastic sheet 200, so that when the actuating elastic sheet 300 is installed from the side, the actuating elastic sheet can extend into the housing 100 along the positioning slope 120 to contact the actuating contact 320 with the fixed contact 210, and in addition, the outer surface of the housing 100 is further provided with a temperature conducting sheet 130, and two ends of the temperature conducting sheet 130 extend into the housing 100 to respectively contact the heat storage element 500 and the fixed elastic sheet 200. When the thermal protection device for the battery is installed, the surface of the shell 100, which is provided with the temperature conduction piece 130, is attached to the battery tightly, so that the temperature of the battery can be conducted to the heat storage original year and the fixed elastic piece 200 through the temperature conduction piece 130, the perception of the thermal protection device for the battery temperature is further enhanced, and the thermal protection device for the battery is too small in size and almost impossible to visually confirm in the installation process, so that the temperature conduction piece 130 can play a limiting role in the shell 100, the length of the temperature conduction piece 130 is the same as the length of the part of the action elastic piece 300 in the shell 100, and thus when the action elastic piece 300 is installed from the side surface, when the heat storage element 500 is abutted to one end of the temperature conduction piece 130, the action contact 320 is just in contact with the fixed contact 210, the installation is ensured to be in place, and the problem that the visual confirmation is not easy to carry out in the side surface installation process is solved.

Further, as shown in fig. 6-7, the fixing clip 200 and the actuating clip 300 may be L-shaped, so that the fixing clip 200 and the actuating clip 300 may be directly connected to an external load (usually a battery) without secondary processing.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (7)

1. Battery thermal protection device, characterized in that, includes, integrated into one piece's shell (100), the lateral part of shell (100) is equipped with opening (110), and it:

the fixed elastic sheet (200), the fixed elastic sheet (200) is provided with a fixed contact (210);

the actuating elastic sheet (300), the actuating elastic sheet (300) and the fixed elastic sheet (200) are arranged oppositely, the actuating elastic sheet (300) is provided with an elastic part (310) and an actuating contact (320) arranged at the front end of the elastic part (310), and the actuating elastic sheet (300) enables the actuating contact (320) and the fixed contact (210) to be contacted with each other through the elastic part (310);

the heat reaction elastic sheet (400), the heat reaction elastic sheet (400) is arranged between the fixed elastic sheet (200) and the action elastic sheet (300), one end of the heat reaction elastic sheet (400) is furled and fixed on the action elastic sheet (300) to form a fixed part (410), the other end of the heat reaction elastic sheet (400) is tightly attached to the action elastic sheet (300), and the heat reaction elastic sheet (400) deforms through the change of temperature to enable the action contact point (320) of the heat reaction elastic sheet to be separated from the fixed contact point (210);

the heat storage element (500) wraps the periphery of the fixing portion (410) and blocks the opening (110) of the shell (100).

2. The thermal battery protection device according to claim 1, wherein the heat storage member (500) is made of a solid-solid phase change material, and a resin sealing cover (510) is provided on an outer side of the heat storage member (500).

3. The thermal battery protection device according to claim 2, wherein the actuating spring (300) is provided with a fixing clip (330), and the fixing clip (330) is used to clamp the fixing portion (410) of the thermal reaction spring (400) from two sides.

4. The thermal battery protection device according to claim 3, wherein the actuating spring (300) is provided with a protrusion (340), and the protrusion (340) is in light contact with the thermal reaction spring (400).

5. The thermal battery protection device according to claim 4, wherein the resilient portion (310) of the actuating spring (300) is provided with an upwardly protruding stress reinforcement (350) on the side facing away from the heat reactive spring (400).

6. Battery thermal protection device according to claim 5, characterized in that the housing (100) is provided with a positioning ramp (120) at the end remote from the opening (110).

7. The thermal battery protection device according to claim 6, wherein a temperature conducting sheet (130) is further disposed on the outer surface of the housing (100), and two ends of the temperature conducting sheet (130) extend into the housing (100) and are respectively in contact with the heat storage element (500) and the fixing spring (200).

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