NTC water temperature sensor

Abstract

The NTC water temperature sensor comprises a thermistor chip, first epoxy resin wrapping the thermistor chip, a lead electrically connected with the thermistor chip, a terminal electrically connected with the lead, and a metal housing. Second epoxy resin is arranged outside the lead; the thermistor chip is arranged in the metal shell, the metal shell is filled with heat-conducting silicone grease, and the heat-conducting silicone grease wraps the first epoxy resin; and one end, close to the terminal, of the metal shell is fixedly connected with a plastic shell. The NTC water temperature sensor provided by the utility model has the advantage of high temperature measurement accuracy.

Description

Technical Field

[0001] The utility model relates to an NTC water temperature sensor, in particular to a thermistor water temperature sensor with high temperature measurement accuracy. Background Technique

[0002] In the field of electric vehicles, temperature sensors are used to monitor the temperature of battery packs to ensure the stable performance of battery packs.

[0003] The performance of temperature sensors is reflected in temperature measurement and control accuracy. At present, the new energy electric vehicles in China are developing rapidly, and the functional stability of power batteries is particularly crucial. Therefore, it is necessary to develop a sensor that can monitor the cooling water temperature of power batteries at any time to track the real-time temperature of the battery and regulate compensation to ensure the long-term normal operation of the power battery. Most of the existing water temperature sensors are installed on the surface of the cooling water pipe in a pipe wall envelope mode, and the direct measurement point is the outer wall of the pipe. Affected by the ambient temperature, the ambient temperature difference is large in summer and winter, and it is difficult to ensure the temperature measurement accuracy by compensation calibration. Therefore, it is urgent to develop a temperature sensor to overcome the defects of the existing technology. Content of the Utility Model

[0004] The purpose of the utility model is to solve the problems in the existing technology and provide a thermistor water temperature sensor with high temperature measurement accuracy.

[0005] The technical solution of the utility model is as follows:

[0006] An NTC water temperature sensor includes a thermistor chip, a first epoxy resin coating the thermistor chip, a lead wire electrically connected to the thermistor chip, a terminal electrically connected to the lead wire, and a metal shell; a second epoxy resin is provided outside the lead wire; the thermistor chip is disposed inside the metal shell, and the metal shell is filled with thermal conductive silicone grease, and the thermal conductive silicone grease coats the first epoxy resin; one end of the metal shell close to the terminal is fixedly connected to a plastic shell.

[0007] As a preferred technical solution, the lead wire is electrically connected to the terminal by welding.

[0008] As a preferred technical solution, the terminal is injection-molded and fixed to the plastic shell.

[0009] As a preferred technical solution, the metal shell is made of one of copper, aluminum and steel.

[0010] As a preferred technical solution, a sealing gasket is provided between the metal shell and the plastic shell.

[0011] An NTC water temperature sensor of the present utility model has a thermistor chip disposed inside a metal housing. The metal housing is inserted into a position to be measured, such as inside a cooling water pipe, so that the thermistor water temperature sensor can directly contact the medium to be measured, ensuring the accuracy of temperature measurement. At the same time, the metal housing has good thermal conductivity, and a thermal conductive silicone grease is provided between the metal housing and the thermistor chip, which can ensure the accuracy and timeliness of temperature conduction. Therefore, an NTC water temperature sensor of the present utility model has the advantage of high temperature measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the overall structure of a specific embodiment of an NTC water temperature sensor of the present utility model;

[0013] Figure 2 is a schematic diagram of the thermistor structure of a specific embodiment of an NTC water temperature sensor of the present utility model;

[0014] Figure 3 is a schematic diagram of the internal encapsulation of a specific embodiment of an NTC water temperature sensor of the present utility model;

[0015] Figure 4 is a partial cross-sectional view of a specific embodiment of an NTC water temperature sensor of the present utility model excluding the metal housing. SPECIFIC EMBODIMENTS

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0017] The terms used in the embodiments of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The singular forms "a", "the", and "said" used in the embodiments of the present utility model and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. "Plural" generally includes at least two, but does not exclude the case of including at least one.

[0018] It should be understood that the term " / and" used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0019] Depending on the context, as used herein, the words "if" and "when" may be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" may be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0020] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a commodity or system comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such commodity or system. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the commodity or system comprising said element.

[0021] As Figure 1 shown is a specific embodiment of an NTC water temperature sensor of the present utility model. An NTC water temperature sensor of this embodiment, as Figure 2 shown, includes a thermistor chip 1, the thermistor chip 1 is coated with a first epoxy resin 2, and the thermistor chip 1 is electrically connected to a lead 4. As Figure 4 shown, the lead 4 is electrically connected to a terminal 5, and a second epoxy resin 3 is disposed outside the lead 4. As Figure 3 shown, the thermistor chip 1 is disposed in a metal housing 7, a thermal grease 6 is disposed in the metal housing 7, the thermal grease 6 coats the thermistor chip 1 and the first epoxy resin 2, and one end of the metal housing 7 close to the terminal 5 is fixedly connected to a plastic housing 8. An NTC water temperature sensor of this embodiment inserts the metal housing 7 into a position to be measured, such as inside a cooling water pipe, so that the thermistor water temperature sensor can directly contact the medium to be measured, ensuring the accuracy of temperature measurement. At the same time, the metal housing 7 has good thermal conductivity, and a thermal grease 6 is disposed between the metal housing 7 and the thermistor chip 1, which can ensure the accuracy and timeliness of temperature conduction.

[0022] To ensure the stability of the connection and simplify the production process, in this embodiment, the lead 4 and the terminal 5 are electrically connected and fixed by welding, and in the actual processing, soldering or spot welding can be used for welding.

[0023] To simplify the production process, in this embodiment, the terminal 5 and the plastic housing 8 are integrally fixed by injection molding to form a male connector.

[0024] In this embodiment, the material of the metal housing 7 is one of copper, aluminum and steel with good thermal conductivity.

[0025] To improve the waterproof effect, as Figure 3 shown, an NTC water temperature sensor in this embodiment further includes a gasket 9, which is arranged between the metal housing 7 and the plastic housing 8 to prevent external water from entering the thermistor 1 along the riveting gap between the metal housing 7 and the plastic housing 8.

[0026] This embodiment also provides a packaging process for manufacturing the above-mentioned thermistor water temperature sensor, including the following steps:

[0027] a. After fixedly electrically connecting the thermistor chip 1 and the lead 4, use the first epoxy resin 2 to coat the thermistor chip 1 and heat it for curing;

[0028] b. Fix the end of the lead 4 far from the thermistor chip 1 to be fixedly electrically connected to the terminal 5;

[0029] c. Use the second epoxy resin 3 to coat the lead 4 and heat it for curing;

[0030] d. Fill the inner cavity of the metal housing 7 with thermal conductive silicone grease 6, and insert the thermistor chip 1 coated with the first epoxy resin 2 into the thermal conductive silicone grease 6;

[0031] e. Fix the metal housing 7 and the plastic housing 8 to be connected.

[0032] Among them, in this embodiment:

[0033] In step a, the thermistor chip 1 is an NTC negative temperature coefficient thermistor chip.

[0034] In step a, the first epoxy resin 2 includes a main agent, a diluent, and a curing agent; the main agent, the diluent, and the curing agent are adjusted and prepared according to a mass ratio of 60:40:20. The function of the first epoxy resin 2 is to wrap the thermistor chip 1 and play a role in waterproofing and insulating the thermistor chip 1.

[0035] In this embodiment, the terminal 5 and the plastic housing 8 are integrally injection-molded to form a male connector. After fixedly electrically connecting the lead 4 and the terminal 5 in step b, at this time, the thermistor chip 1 is fixedly combined with the plastic housing 8 through the lead 4 and the terminal 5. To ensure the stability of the combination and simplify the processing technology, in this embodiment, in step b, the lead 4 and the terminal 5 are fixedly electrically connected by welding. In actual applications, they can be welded and fixed by soldering or spot welding according to needs, and there is no need to connect them by wire lapping.

[0036] In step c, the second epoxy resin 3 includes a main agent, a diluent, and a curing agent; the main agent, the diluent, and the curing agent are adjusted and prepared according to a mass fraction of 70:30:20. The function of the second epoxy resin 3 is to wrap the lead 4 and increase the withstand voltage level between the lead 4 and the housing 7.

[0037] In step d, the filling amount of the thermal conductive silicone grease 6 should cover the thermistor chip 1.

[0038] Before fixing the metal shell 7 and the plastic housing 8 in step e of this embodiment, a gasket 9 is first arranged on the inner wall of the metal shell 7, and then the metal shell 7 and the plastic housing 8 are riveted and fastened. The shape of the gasket 9 corresponds to the shape of the inner wall of the metal shell 7 to prevent external water from entering the thermistor chip 1 along the riveting gap between the metal shell 7 and the plastic housing 8. The metal shell 7 and the plastic housing 8 are fastened by press riveting or spin riveting.

[0039] Before using an NTC water temperature sensor of this embodiment, insert the metal shell 7 into the cooling water pipe, and the thermistor water temperature sensor directly contacts the water for temperature detection.

[0040] For an NTC water temperature sensor of the present utility model, a thermistor chip is arranged inside a metal shell. By inserting the metal shell into a position to be measured such as the inside of a cooling water pipe, the thermistor water temperature sensor can directly contact the medium to be measured, ensuring the accuracy of temperature measurement. At the same time, the metal shell has good thermal conductivity, and a thermal conductive silicone grease is arranged between the metal shell and the thermistor chip, which can ensure the accuracy and timeliness of temperature conduction. Therefore, an NTC water temperature sensor of the present utility model has the advantage of high temperature measurement accuracy.

[0041] In summary, the above are only preferred embodiments of the present utility model and are not used to limit the scope of implementation of the present utility model. That is, all equivalent changes and modifications made according to the content of the scope of the patent application of the present utility model shall fall within the technical scope of the present utility model.

Claims

1. An NTC water temperature sensor, characterized in that: The invention comprises a thermistor chip, a first epoxy resin coating the thermistor chip, a lead wire electrically connected to the thermistor chip, a terminal electrically connected to the lead wire, and a metal shell; a second epoxy resin is arranged outside the lead wire; the thermistor chip is arranged in the metal shell, the metal shell is filled with thermal conductive silicone grease, and the thermal conductive silicone grease coats the first epoxy resin; and one end of the metal shell close to the terminal is fixedly connected to a plastic shell.

2. The NTC water temperature sensor according to claim 1, characterized in that: The lead wire is electrically connected to the terminal by welding.

3. The NTC water temperature sensor according to claim 1, characterized in that: The terminal is fixed to the plastic housing by injection molding.

4. The NTC water temperature sensor according to claim 1, characterized in that: The metal shell is made of copper, aluminum and steel.

5. The NTC water temperature sensor according to claim 1, characterized in that: A sealing gasket is arranged between the metal shell and the plastic shell.

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