Temperature sensing probe and battery over-temperature protection system

Abstract

The utility model discloses a temperature sensing probe and a battery over-temperature protection system. The temperature sensing probe comprises a sensing optical fiber, a temperature sensing terminal and a shell, wherein the sensing optical fiber comprises a first end face, a second end face, a first outer wall adjacent to the second end face and a second outer wall far away from the second end face; the first end face is used for receiving and emitting light; the first outer wall comprises a first thermosensitive layer, and the second outer wall comprises a conductive layer connected with the first thermosensitive layer; the temperature sensing terminal comprises a light incident surface and a reflecting surface, the light incident surface is coupled to the second end surface, and the reflecting surface is provided with a second thermosensitive layer; the housing is used for accommodating the sensing optical fiber and the temperature sensing terminal. According to the technical scheme provided by the utility model, one end of the temperature sensing probe is dual-purpose, bistable temperature monitoring is carried out by using two properties of the heat-sensitive material, and the precision and reliability of real-time temperature monitoring are improved.

Description

TECHNICAL FIELD

[0001] The utility model embodiment relates to overtemperature protection technical field, especially, it relates to a temperature sensing probe and battery overtemperature protection system. BACKGROUND

[0002] Under the background of popularization of mobile electronic devices such as mobile phones, mobile power gradually becomes a necessity in people's life due to its portability. Considering the cost, the current mobile power usually uses a battery with low safety, which may cause heating problem during operation. When the heating temperature is too high, it may cause severe burning, which has certain safety hazards.

[0003] The current battery protection scheme for the heating problem usually sets a thermistor inside the mobile power, and measures the resistance value through the related functional circuit to realize temperature monitoring. Due to the limitation of the accuracy of resistance value calculation of the thermistor used at present, the control accuracy of the existing scheme for a specific temperature is not high, and the stability is poor. INVENTION CONTENTS

[0004] The utility model embodiment provides a temperature sensing probe and a battery overtemperature protection system to improve the accuracy of real-time temperature monitoring in the battery product, thereby improving the accuracy and stability of specific temperature control.

[0005] In a first aspect, the utility model embodiment provides a temperature sensing probe, which comprises a sensing optical fiber, a temperature sensing terminal and a shell, wherein,

[0006] The sensing optical fiber comprises a first end face, a second end face, a first outer wall adjacent to the second end face and a second outer wall away from the second end face; the first end face is used for receiving and emitting light; the first outer wall comprises a first thermosensitive layer, and the second outer wall comprises a conductive layer connected with the first thermosensitive layer;

[0007] The temperature sensing terminal comprises a light entrance surface and a reflecting surface, the light entrance surface is coupled to the second end face, and the reflecting surface is provided with a second thermosensitive layer;

[0008] The shell is used for containing the sensing optical fiber and the temperature sensing terminal.

[0009] Optionally, the sensing optical fiber comprises an incident optical fiber and an emergent optical fiber arranged side by side, and the incident optical fiber and the emergent optical fiber are combined into a bundle of reflected optical fibers adjacent to the second end face.

[0010] Optionally, the reflected optical fiber comprises an incident light core arranged in the center and a plurality of emergent light cores surrounding the incident light core.

[0011] Optionally, the temperature sensing probe further comprises a fiber conversion module for merging the incident fiber and the outgoing fiber into the reflected fiber.

[0012] Optionally, the first and second thermosensitive layers comprise vanadium dioxide.

[0013] In a first aspect, the utility model embodiment further provides a battery over-temperature protection system, the system includes the temperature sensing probe provided by any embodiment of the utility model, further includes battery module, electric signal module and optical signal module, wherein,

[0014] The temperature sensing probe is attached to the surface of the battery module.

[0015] The electric signal module is connected with the first thermosensitive layer through the conductive layer, and is used for generating a first temperature signal according to the resistance of the first thermosensitive layer.

[0016] The optical signal module is coupled with the first end face, and is used for receiving light reflected by the second thermosensitive layer to generate a second temperature signal.

[0017] Optionally, the optical signal module comprises an optical transmitting circuit and an optical receiving circuit; the optical transmitting circuit is used for generating infrared signal light and incident to the first end face; and the optical receiving circuit is used for receiving infrared signal light reflected by the second thermosensitive layer and converting into the second temperature signal.

[0018] Optionally, the system further comprises a first digital-analog conversion module, which is used for converting the second temperature signal into a digital signal.

[0019] Optionally, the electric signal module comprises a thermosensitive conversion circuit, and the thermosensitive conversion circuit comprises the first thermosensitive layer and a voltage dividing resistor connected in series between a direct current voltage and ground, so as to generate the first temperature signal according to the resistance voltage division of the first thermosensitive layer.

[0020] Optionally, the system further comprises a second digital-analog conversion module, which is used for converting the first temperature signal into a digital signal.

[0021] The utility model discloses an embodiment provides a kind of temperature sensing probe, including sensing optical fiber, temperature sensing terminal and shell, sensing optical fiber includes first end surface, second end surface, first outer wall adjacent to second end surface and second outer wall away from second end surface, the first end surface in it is used to receive and emit light, first outer wall includes first thermosensitive layer, second outer wall includes the conductive layer connected first thermosensitive layer, temperature sensing terminal includes light entrance surface and reflecting surface, wherein, light entrance surface is coupled to second end surface, reflecting surface is provided with second thermosensitive layer, shell is used to accommodate sensing optical fiber and temperature sensing terminal. The temperature sensing probe provided in the embodiment of the utility model can realize temperature measurement based on resistance change by first thermosensitive layer and conductive layer, and can realize temperature measurement based on reflectivity change by second thermosensitive layer and sensing optical fiber, so that the temperature sensing probe one end dual-purpose is realized, double-stable temperature monitoring is carried out using two properties of thermosensitive material, when one of the sensing modes fails, the other can still be normally monitored, the accuracy and reliability of real-time temperature monitoring are improved, and then the accuracy and stability for specific temperature control can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The structure schematic view of the temperature sensing probe provided by the embodiment of the utility model one provides;

[0023] Figure 2 The structure schematic view of another temperature sensing probe provided by the embodiment of the utility model one provides;

[0024] Figure 3 The internal optical path structure schematic view of optical fiber provided by the embodiment of the utility model one provides;

[0025] Figure 4 The temperature characteristic curve of vanadium dioxide provided by the embodiment of the utility model one provides;

[0026] Figure 5 The structure schematic view of a kind of battery product provided by the embodiment of the utility model two provides;

[0027] Figure 6 The optical signal module circuit diagram provided by the embodiment of the utility model two provides;

[0028] Figure 7 The electric signal module circuit diagram provided by the embodiment of the utility model two provides. DETAILED DESCRIPTION

[0029] The utility model will be further described in detail in connection with the drawings and embodiments.It can be understood that the specific embodiments described herein are only used to explain the utility model, not limit the utility model.In addition, it needs to be explained that, in order to facilitate description, only part relevant to the utility model is shown in the drawings, not all structures.

[0030] Furthermore, the terms "first," "second," etc., may be used herein to describe various directions, actions, steps, or elements, but these directions, actions, steps, or elements are not limited by these terms. These terms are only used to distinguish a first direction, action, step, or element from another direction, action, step, or element. For example, without departing from the scope of the embodiments of the present invention, a first end face may be referred to as a second end face, and similarly, a second end face may be referred to as a first end face. Both the first end face and the second end face are end faces, but they are not the same end face. The terms "first," "second," etc., should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] Example 1

[0032] Figure 1 This is a schematic diagram of the temperature sensing probe provided in Embodiment 1 of this utility model. This embodiment is applicable to temperature monitoring of various battery products, especially in the confined spaces inside power banks, for various specific temperature control situations. Figure 1 As shown, the temperature sensing probe includes: a sensing optical fiber, a temperature sensing terminal 15, and a housing; wherein, the sensing optical fiber includes a first end face, a second end face, a first outer wall adjacent to the second end face, and a second outer wall away from the second end face (the outer wall 13 of the optical fiber includes the first outer wall and the second outer wall); the first end face is used to receive and emit light; the first outer wall includes a first thermistor layer 14, and the second outer wall includes a conductive layer 11 connected to the first thermistor layer 14; the temperature sensing terminal 15 includes a light-incident surface and a reflective surface, the light-incident surface is coupled to the second end face, and the reflective surface is provided with a second thermistor layer 16; the housing is used to house the sensing optical fiber and the temperature sensing terminal 15.

[0033] Specifically, the first thermistor layer 14 and the second thermistor layer 16 can be made of nonlinear phase-change thermistor materials and are respectively deposited on the first outer wall and the reflective surface of the temperature-sensing terminal 15. They can be fabricated using thin-film technology to achieve higher sensitivity. The conductive layer 11 can be a wall-mounted metal electrode and is connected to the first thermistor layer 14 on the second outer wall to lead out the first thermistor layer 14 for easy electrical connection to the outside. The metal electrode can be of any shape, as long as the first thermistor layer 14 is led out at both ends. The sensing optical fiber can receive incident light (specifically, infrared signal light) from the first end face and transmit it to the temperature-sensing terminal 15 coupled to the second end face. The light is reflected by the second thermistor layer 16 on the reflective surface of the temperature-sensing terminal 15 and returns to the first end face of the sensing optical fiber.Figure 2 As shown, the sensing optical fiber 31 can be arranged in the shell 33 and can be fixed by the clamp 32 in the shell 33, and the temperature sensing terminal 15 can be arranged close to the shell 33. The sensing optical fiber 31 can be arranged in single or multiple, and is respectively connected with the corresponding temperature sensing terminal 15. The more the number of the sensing optical fiber 31 is, the better the temperature monitoring effect is, and the higher the system safety is, but the structure is relatively complex. The clamp 32 can be any structure and any position, and can fix the sensing optical fiber 31. The temperature sensing terminal 15 can be made of flexible material and can be small in size, so that it can be flexibly fixed at the temperature sensitive position of various battery products, is strong in adaptability, and can comprehensively monitor the temperature of the battery product.

[0034] Based on the above technical solutions, optionally, Figure 1 As shown, the sensing optical fiber includes the incident optical fiber 20 and the outgoing optical fiber 21 arranged side by side, and the incident optical fiber 20 and the outgoing optical fiber 21 are merged into a bundle of reflected optical fiber 12 adjacent to the second end face. Specifically, the incident light can be incident from the first end face of the incident optical fiber 20, transmitted through the incident optical fiber 20, then enter the reflected optical fiber 12 through optical path conversion, and then be reflected by the second thermal sensitive layer 16 on the reflecting surface of the temperature sensing terminal 15, re-enter the reflected optical fiber 12, then enter the outgoing optical fiber 21 through optical path conversion, and finally be emitted from the first end face of the outgoing optical fiber 21.

[0035] Further optionally, as shown in Figure 3 The reflected optical fiber 12 includes the incident light core 26 arranged in the center and the multiple outgoing light cores 25 surrounding the incident light core 26. Preferably, the outgoing light core 25 is evenly distributed in eight. Correspondingly, the incident optical fiber 20 includes the incident light core 26 arranged in the center, and the outgoing optical fiber 21 includes the outgoing light core 25 which is distributed in the same way as the outgoing light core 25 in the reflected optical fiber 12, so as to propagate the light path. In the temperature sensing terminal 15, the incident light is emitted to the surface of the second thermal sensitive layer 16 through the incident light core 26 in the reflected optical fiber 12, and is reflected back to the outgoing light core 25 in the reflected optical fiber 12 for propagation.

[0036] Further optionally, as shown in Figure 1 and Figure 3As shown, the temperature sensing probe further comprises a fiber conversion module 18 for merging the incident fiber 20 and the outgoing fiber 21 into the reflective fiber 12. Specifically, the fiber conversion module 18 can convert the light path of the light rays emitted from the incident light core 26 in the incident fiber 20 to transmit the light rays into the corresponding incident light core 26 in the reflective fiber 12, and convert the light path of the light rays emitted from the outgoing light core 25 in the reflective fiber 12 to transmit the light rays into the corresponding outgoing light core 25 in the outgoing fiber 21. Further, a connecting electrode 17 can be arranged on the fiber conversion module 18, and the conductive layer 11 can be connected to the metal wire 19 through the connecting electrode 17 to better lead out the first thermosensitive layer 14 through the metal wire 19.

[0037] On the basis of the above-mentioned scheme, optionally, the first thermosensitive layer 14 and the second thermosensitive layer 16 comprise vanadium dioxide VO2. The temperature characteristic curve of vanadium dioxide is as shown in the following figure: Figure 4 As shown, when the temperature rises to the first threshold temperature T1, the properties of the thermosensitive material (such as transmittance, reflectance and resistance value) will have a nonlinear mutation, from a high value to a low value, and the change is a change of orders of magnitude. The phase transition temperature T1 at room temperature is about 68℃, which is close to the upper limit temperature 70℃ of the lithium battery, and has a higher matching degree. And when the temperature drops, the corresponding properties will not return along the original temperature rising curve, but will also have a nonlinear mutation when the temperature drops to the second threshold temperature T2 (T2 < T1), from a low value to a high value, that is, there is a thermal hysteresis width between the mutation from a high value to a low value and the mutation from a low value to a high value. Then the first thermosensitive layer 14 mainly utilizes the resistance mutation property of the thermosensitive material to monitor the temperature, and the second thermosensitive layer 16 mainly utilizes the infrared reflectance mutation property of the thermosensitive material to monitor the temperature. Further, different application scenarios can be combined to dope one or more elements in the vanadium dioxide material to change the threshold temperature. In addition, GST series materials with higher threshold temperature or other threshold temperature nonlinear phase change materials can also be used.

[0038] The temperature sensing probe provided by the embodiment of the utility model, including sensing optical fiber, temperature sensing terminal and shell, sensing optical fiber includes first end surface, second end surface, first outer wall adjacent to second end surface and second outer wall away from second end surface, first end surface in it is used for receiving and emitting light, first outer wall includes first thermosensitive layer, second outer wall includes conductive layer connected first thermosensitive layer, temperature sensing terminal includes light entrance surface and reflection surface, wherein, light entrance surface is coupled to second end surface, reflection surface is provided with second thermosensitive layer, shell is used for containing sensing optical fiber and temperature sensing terminal. Through first thermosensitive layer and conductive layer, temperature measurement based on resistance change can be realized, through second thermosensitive layer and sensing optical fiber, temperature measurement based on reflectivity change can be realized, so that one end of temperature sensing probe is dual-purpose is realized, two properties of thermosensitive material are utilized to carry out bistable temperature monitoring, when one kind of sensing mode fails, another kind still can normally monitor, the accuracy and reliability of real-time temperature monitoring are improved, and then the accuracy and stability for specific temperature control can be improved.

[0039] Embodiment two

[0040] The utility model embodiment two provides a kind of battery over-temperature protection system, and the system includes the temperature sensing probe provided by any embodiment of the utility model, still include battery module, electric signal module and optical signal module;Wherein, the temperature sensing probe is attached the surface of the battery module setting;The electric signal module is connected with the first thermosensitive layer by the conductive layer, for generating first temperature signal according to the resistance of the first thermosensitive layer;The optical signal module is coupled with the first end surface, for receiving the light reflected by the second thermosensitive layer and generating second temperature signal.

[0041] Specifically, as shown in Figure 1 The first thermosensitive layer 14 can be connected to metal wire 19 through conductive layer 11 and connecting electrode 17, metal wire 19 can be connected to control panel 1 of battery product, and access electric signal module 23 through on-board wire 24, so that electric signal module 23 can generate first temperature signal according to the resistance of first thermosensitive layer 14. Optical signal module 22 is coupled with the first end surface of temperature sensing probe, and can send light to incident optical fiber 20, and receive the light emitted by emergent optical fiber 21, to generate second temperature signal according to the received light. As shown in Figure 5 Temperature sensing probe 4 can be attached to the surface of battery module 5, and can be connected with control panel 1 through probe connecting line 6. By setting temperature sensing probe 4 on battery module 5, faster response temperature sensing early warning can be realized. Of course, the position of temperature sensing probe 4 is not fixed, and can be flexibly set at any temperature-sensitive position inside battery product, or multiple temperature sensing probes 4 can be set to monitor different positions respectively, to speed up the response to battery temperature change.

[0042] Optionally, the optical signal module 22 comprises an optical transmitting circuit and an optical receiving circuit; the optical transmitting circuit is configured to generate infrared signal light and make the infrared signal light incident on the first end surface; and the optical receiving circuit is configured to receive infrared signal light reflected by the second thermosensitive layer and convert the infrared signal light into the second temperature signal. Specifically, as shown in Figure 6 The optical transmitting circuit can comprise a first driving module 54 and a light emitting module 55, and the optical receiving circuit can comprise a light receiving module 56 and a filtering module 57. The first driving module 54 uses a triode U2 to amplify the driving capability of an IO port and then controls a switch MOS tube Q2 to control a power supply VCC to supply power to the light emitting module 55, thereby providing a control basis for multi-path monitoring and inspection. A light emitting diode LED2 in the light emitting module 55 can be a laser diode for sending infrared signal light, so as to send the infrared signal light into the incident optical fiber 20. The reflected signal light returned by the outgoing optical fiber 21 can be detected by a photodiode LED3 in the light receiving module 56, and the photodiode LED3 generates a photoelectric current signal which is converted into a photoelectric voltage signal through an adjustable resistor R6, and then a low-pass filter circuit in the filtering module 57 outputs a second temperature signal. When the temperature changes, the intensity of the reflected signal light changes, thereby generating a signal change. Further optionally, the system further comprises a first digital-to-analog conversion module for converting the second temperature signal into a digital signal, so as to perform specific temperature control.

[0043] Optionally, the electrical signal module comprises a thermosensitive conversion circuit, and the thermosensitive conversion circuit comprises the first thermosensitive layer 14 and a voltage dividing resistor connected in series between a direct current voltage and the ground, so as to generate the first temperature signal according to the voltage division of the first thermosensitive layer 14. Specifically, as shown in Figure 7 The thermosensitive conversion circuit can comprise a second driving module 51, a voltage dividing module 52 and an operational amplifier module 53. The second driving module 51 uses a triode U1 to amplify the driving capability of an IO port and then controls a switch MOS tube Q1 to control a power supply VCC to supply power to the voltage dividing module 52, thereby providing a control basis for multi-path monitoring and inspection. The voltage dividing module 52 can be connected to both ends of the on-board wire 24 through a jumper CN1, so as to access the first thermosensitive layer 14. A voltage dividing resistor RS1 divides the voltage with the first thermosensitive layer 14, so as to convert the resistance change of the first thermosensitive layer 14 into a voltage signal change at the end of the voltage dividing resistor RS1 when the temperature changes. Then, the operational amplifier module 53 can output a first temperature signal according to the voltage at the end of the voltage dividing resistor RS1 through an operational amplifier U5.1. Further optionally, the system further comprises a second digital-to-analog conversion module for converting the first temperature signal into a digital signal, so as to perform specific temperature control. Correspondingly, the operational amplifier U5.1 can also reduce the input resistance of the second digital-to-analog conversion module to improve the identification accuracy.

[0044] On the basis of the above technical solutions, as shown in Figure 5As shown, a conventional negative temperature coefficient thermistor 2 can also be provided on the control board 1 to provide over-temperature protection for the control board 1, so that a faster response speed to the temperature change of the battery can be achieved through more sensing probes for sensing the temperature. All the above structures can be housed by the product housing 3 for protection. Of course, when the temperature of the battery module 5 is abnormal, the temperature sensing probe 4 provided on the battery module 5 can respond faster than the thermistor 2 on the control board 1, and the conventional rigid thermistor cannot be flexibly used in various parts of the battery product to monitor the temperature, but is limited to temperature monitoring of a small limited area on the circuit board where it can be installed.

[0045] Further, by using the properties of the nonlinear phase change thermosensitive material, in the over-temperature control application, when the temperature sensing probe 4 detects that the over-temperature occurs (i.e. the temperature exceeds the first threshold temperature T1), the control board 1 can sense the signal change and then start the over-temperature protection to cut off the charging of the battery module 5, and when the temperature cools down to below the second threshold temperature T2, the control board 1 can resume the charging of the battery module 5 to make the product work normally. Since the properties of the nonlinear phase change thermosensitive material change by orders of magnitude before and after the phase change, the risk of misjudgment is less likely to occur compared to the conventional thermistor, overcoming the small change of physical quantity with temperature in the conventional linear device, and a complex amplification circuit is not needed. At the same time, because of the large thermal hysteresis width, when the properties return to the high resistance state, the control board determines that it can resume work, that is, it has dropped to a safe temperature, leaving a large redundant temperature range for the control board to identify, and the reversibility is good. In addition, the threshold temperature can also be adjusted through the preparation process to meet the needs of various application scenarios, and the comprehensive over-temperature protection of the battery product can be simply and efficiently achieved.

[0046] Note that the above is only a preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A temperature sensing probe, characterized in that, include: The sensing fiber, temperature sensing terminal, and housing; among which, The sensing optical fiber includes a first end face, a second end face, a first outer wall adjacent to the second end face, and a second outer wall away from the second end face; the first end face is used to receive and emit light; the first outer wall includes a first thermosensitive layer, and the second outer wall includes a conductive layer connected to the first thermosensitive layer. The temperature sensing terminal includes a light-incident surface and a reflective surface, the light-incident surface is coupled to the second end face, and the reflective surface is provided with a second thermal layer; The housing is used to house the sensing optical fiber and the temperature sensing terminal.

2. The temperature sensing probe according to claim 1, characterized in that, The sensing optical fiber includes an incident optical fiber and an outgoing optical fiber arranged side by side, and the incident optical fiber and the outgoing optical fiber are combined into a reflective optical fiber near the second end face.

3. The temperature sensing probe according to claim 2, characterized in that, The reflective optical fiber includes an incident optical core located at the center and multiple outgoing optical cores surrounding the incident optical core.

4. The temperature sensing probe according to claim 2, characterized in that, The temperature sensing probe also includes an optical fiber conversion module for merging the incident optical fiber and the outgoing optical fiber into the reflecting optical fiber.

5. The temperature sensing probe according to claim 1, characterized in that, The first and second thermistor layers comprise vanadium dioxide.

6. A battery over-temperature protection system, characterized in that, Including the temperature sensing probe as described in any one of claims 1-5, it further includes a battery module, an electrical signal module, and an optical signal module; wherein, The temperature sensing probe is attached to the surface of the battery module. The electrical signal module is connected to the first thermistor layer through the conductive layer, and is used to generate a first temperature signal based on the resistance of the first thermistor layer. The optical signal module is coupled to the first end face and is used to receive light reflected by the second thermal layer to generate a second temperature signal.

7. The battery over-temperature protection system according to claim 6, characterized in that, The optical signal module includes an optical emitting circuit and an optical receiving circuit; the optical emitting circuit is used to generate infrared signal light and incident it onto the first end face; the optical receiving circuit is used to receive the infrared signal light reflected by the second thermosensitive layer and convert it into the second temperature signal.

8. The battery over-temperature protection system according to claim 7, characterized in that, The system also includes a first digital-to-analog converter module for converting the second temperature signal into a digital signal.

9. The battery over-temperature protection system according to claim 6, characterized in that, The electrical signal module includes a thermistor conversion circuit, which includes a first thermistor layer connected in series between the DC voltage and ground and a voltage divider resistor to generate the first temperature signal based on the resistance of the first thermistor layer.

10. The battery over-temperature protection system according to claim 9, characterized in that, The system also includes a second digital-to-analog converter module for converting the first temperature signal into a digital signal.

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