A temperature sensor with high insulation and high voltage resistance

Abstract

The utility model relates to temperature sensor field, concretely is a kind of temperature sensor of high insulation high pressure resistance, it includes: a thermistor;A first wire is welded in the first pin of thermistor;A second wire is welded in the second pin of thermistor;A first sleeve of polytetrafluoroethylene material is used to set thermistor, and first wire, second wire are drawn from the same end of first sleeve side by side;A second sleeve of polytetrafluoroethylene material is arranged in first sleeve interior, for the connecting portion of second pin and second wire is set;A sleeve plug of polytetrafluoroethylene material is tightly fitted in the other end of second sleeve relative to the leading end of first wire, second wire;A metal shell, and metal shell is filled with epoxy resin from open end to encapsulate and fix the thermistor, first sleeve, second sleeve, first wire, second wire and sleeve plug in interior.The utility model is high in production efficiency, and the insulation pressure resistance performance of finished product is excellent, consistent, reliable.

Description

Technical Field

[0001] This utility model relates to the field of temperature sensors, specifically a high-insulation, high-voltage-resistant temperature sensor. Background Technology

[0002] In the prior art, one type of temperature sensor is known to be made of a thermistor, and its structure is typically as follows: Figure 1 As shown, it includes a thermistor 1', with a wire soldered to each of the two legs of the thermistor 1', and then coated with epoxy resin 2' for insulation. The wires are mostly connected to the circuit control board or control cabinet, while the temperature sensor is usually in direct contact with the equipment housing. This requires improving the insulation withstand voltage performance of the temperature sensor to prevent it from being broken down by voltage.

[0003] To address this, existing technologies typically employ the following methods to improve the insulation withstand voltage performance of the aforementioned temperature sensors:

[0004] (1) After applying epoxy resin for insulation coating, the whole assembly is installed in the metal casing 3', and then epoxy resin is potted inside the metal casing. Since epoxy resin is liquid, the coating quality is not easy to control, and the coating thickness depends entirely on visual inspection, which can easily lead to inconsistent or substandard insulation thickness. Figure 2 In the scenario shown, if the epoxy resin 2' coating is too thin, it will directly lead to poor insulation withstand voltage performance. Figure 3 In the scenario shown, the epoxy resin 2' coating is too thick, making it difficult to insert into the metal casing for potting.

[0005] Moreover, the above method also poses a risk of damage to the thermistor due to high-voltage arcing breaking down the metal casing.

[0006] (2) Based on the former method, such as Figure 4 As shown, after applying epoxy resin insulation coating, a PVC insulating sleeve 4' is first installed to avoid the risk of high-voltage arcing, and then the entire assembly is installed into the metal casing 3' and potted with epoxy resin. When potting epoxy resin into the metal casing 3', the PVC insulating sleeve 4' has significant heat shrinkage properties, and its heat shrinkage process can easily cause a large number of air bubbles in the potted epoxy resin; these air bubbles may cause a short circuit between the two pins of the thermistor, and may also weaken the avoidance effect against high-voltage arcing.

[0007] On the other hand, the existing technologies mentioned above can usually only achieve an AC1500V withstand voltage value. However, in higher voltage working scenarios such as high and low voltage power cabinets, new energy charging guns, and high voltage equipment, it may be desirable to achieve an AC6000V withstand voltage value. Existing technologies cannot ideally support the needs of such higher voltage working scenarios. Utility Model Content

[0008] The present invention aims to overcome the above-mentioned deficiencies of the prior art by optimizing the packaging method, thereby improving the insulation and withstand voltage performance of the temperature sensor.

[0009] To achieve the above objectives, the present invention adopts the following technical solution.

[0010] A high-insulation, high-voltage-resistant temperature sensor, comprising:

[0011] A thermistor is a two-ended device with a first pin and a second pin.

[0012] A first wire is soldered to the first pin of the thermistor;

[0013] A second wire is soldered to the second pin of the thermistor;

[0014] A first sleeve made of polytetrafluoroethylene is used to house the thermistor, the connection between the first pin and the first wire, and the connection between the second pin and the second wire. The first wire and the second wire are led out side by side from the same end of the first sleeve.

[0015] A second sleeve made of polytetrafluoroethylene is located inside the first sleeve and is used to fit the connection between the second pin and the second wire, so that the second pin and the second wire are insulated and isolated from the first pin and the first wire.

[0016] A sleeve made of polytetrafluoroethylene is tightly fitted to the other end of the second sleeve relative to the lead-out ends of the first and second wires;

[0017] A metal outer shell is a cylindrical structure fitted around the outside of the first sleeve with a clearance fit. One end of the shell is open to allow the first sleeve to be inserted, while the other end is closed to block the plug.

[0018] Furthermore, the metal casing is filled with epoxy resin from the open end to encapsulate and fix the internal thermistor, first sleeve, second sleeve, first wire, second wire, and plug.

[0019] Compared with the prior art, this utility model has the following advantages: the use of a polytetrafluoroethylene sleeve and plug to insulate and protect the two pins of the thermistor and the corresponding wires makes the overall size of the product controllable and the product shape highly consistent. The subsequent epoxy resin potting process is simple, the production efficiency is high, and the insulation and withstand voltage performance of the finished product is excellent, consistent and reliable.

[0020] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a type of temperature sensor known in the prior art.

[0022] Figure 2 This is an assembly diagram of a type of temperature sensor known in the prior art. Figure 1 .

[0023] Figure 3 This is an assembly diagram of a type of temperature sensor known in the prior art. Figure 2 .

[0024] Figure 4 This is an assembly diagram of a type of temperature sensor known in the prior art. Figure 3 .

[0025] Figure 5 This is a schematic diagram of the structure of this utility model.

[0026] Figure 6 This is an exploded view of the structure of this utility model.

[0027] Figure 7 This is a schematic diagram of the internal structure of this utility model. The epoxy resin is omitted in the diagram for the purpose of showing the internal structure.

[0028] Figure 8 yes Figure 3 Enlarged view of the local structure at point A in the middle.

[0029] Explanation of reference numerals in the attached figures:

[0030] Thermistor 10, first pin 11, second pin 12, first wire 21, second wire 22, first sleeve 31, second sleeve 32, plug 33, round end 331, plug part 332, metal shell 40, epoxy resin 50. Detailed Implementation

[0031] Combination Figures 5 to 8 As shown, in one embodiment, the present invention provides a high-insulation, high-voltage-resistant temperature sensor, the structure of which includes:

[0032] A thermistor 10 is a two-terminal device with a first pin 11 and a second pin 12;

[0033] A first wire 21 is soldered to the first pin 11 of the thermistor 10;

[0034] A second wire 22 is soldered to the second pin 12 of the thermistor 10;

[0035] A first sleeve 31 made of polytetrafluoroethylene is used to sleeve the thermistor 10, the connection part of the first pin 11 and the first wire 21, and the connection part of the second pin 12 and the second wire 22. The first wire 21 and the second wire 22 are led out side by side from the same end of the first sleeve 31.

[0036] A second sleeve 32 made of polytetrafluoroethylene is disposed inside the first sleeve 31 and is used to sleeve the connection part of the second pin 12 and the second wire 22, so that the second pin 12 and the second wire 22 are insulated and isolated from the first pin 11 and the first wire 21.

[0037] A sleeve 33 made of polytetrafluoroethylene is tightly fitted to the other end of the second sleeve 32 relative to the lead-out ends of the first wire 21 and the second wire 22;

[0038] A metal outer shell 40 is a cylindrical structure fitted around the outside of the first sleeve 31 with a clearance fit. One end of the shell is open to insert the first sleeve 31, while the other end is closed to block the plug 33.

[0039] Furthermore, the metal casing 40 is filled with epoxy resin 50 from the open end to encapsulate and fix the internal thermistor 10, first sleeve 31, second sleeve 32, first wire 21, second wire 22 and plug 33.

[0040] In the above embodiment, after the thermistor 10 is connected to the first wire 21 and the second wire 22, the second wire 22 is first fitted into the second sleeve 32. Then, the second wire 22 moves the second sleeve 32 to the connection part between the second pin 12 and the second wire 22, so that the second pin 12 and the second wire 22 are insulated and isolated relative to the first pin 11 and the first wire 21 to prevent short circuit between the two connections. Then, the whole assembly is fitted into the first sleeve 31. The first sleeve 31 covers the thermistor 10, the connection part between the first pin 11 and the first wire 21, and the second sleeve 32, enhancing the overall insulation and withstand voltage performance. Then, the plug 33 is installed at the end of the first sleeve 31 to form a tight fit, preventing arcing phenomenon caused by high insulation withstand voltage. Finally, the first sleeve 31 and the device it covers are inserted into the outer shell, and epoxy resin with good flowability is injected from the open end of the first sleeve 31 for potting. The epoxy resin will automatically fill the internal gaps.

[0041] In the above embodiment, the first sleeve 31, the second sleeve 32, and the plug 33 are all made of polytetrafluoroethylene (PTFE), commonly known in the industry as Teflon. The PTFE-made first sleeve 31 and second sleeve 32 provide ideal insulation between the metal casing 40 and the internal thermistor 10, as well as the thermistor 10's first pin 11, second pin 12, first wire 21, and second wire 22. Simultaneously, the PTFE plug 33 also provides ideal insulation at the closed end of the metal casing 40, and also buffers the contact stress between the thermistor 10 and the closed end of the metal casing 40, forming good mechanical protection. Furthermore, since the first sleeve 31, the second sleeve 32, and the plug 33 are all made of PTFE, their withstand voltage is as high as AC6000V.

[0042] Furthermore, in the above embodiment, the polytetrafluoroethylene material of the first sleeve 31 and the second sleeve 32 can withstand temperatures up to 260°C, while the maximum baking temperature to ensure epoxy resin flow is only 100°C. Therefore, when the metal casing 40 is potted with epoxy resin, the first sleeve 31 and the second sleeve 32 will not shrink or deform due to heat, thus preventing the formation of obvious air bubbles or voids in the potted epoxy resin, further avoiding the occurrence of short circuits between the two pins of the thermistor 10 and high-voltage arcing.

[0043] In summary, this invention optimizes the process structure of the temperature sensor from the perspective of high insulation and high withstand voltage design. There is no short circuit in the metal pins of the product components. The overall size of the product is controllable and the product shape is highly consistent, which not only meets the assembly requirements but also achieves the purpose of insulation and withstand voltage.

[0044] Tests have shown that the high-insulation, high-voltage-resistant temperature sensor provided by this invention can stably withstand AC6000V for 1 minute without breakdown or flashover.

[0045] Meanwhile, the product's overall insulation and withstand voltage protection are seamless, effectively preventing arcing phenomena that can occur under high withstand voltage.

[0046] Optionally, the thermistor 10 is a glass-sealed radial NTC thermistor, a glass-sealed diode-type NTC thermistor, or a thin-film platinum resistance thermometer. Further, the thin-film platinum resistance thermometer is PT100 or PT1000.

[0047] Better, such as Figure 8 As shown, the plug 33 has a circular end 331 with an outer diameter larger than that of the first sleeve 31, and one end of the circular end 331 is coaxially formed to form an insertion portion 332 that is tightly fitted into the first sleeve 31.

[0048] Furthermore, the insertion part 332 is cylindrical. (Combined) Figure 7-8 As shown, the plug 33 is tightly fitted to the end of the first sleeve 31 through the insertion part 332, which not only achieves insulation and high-voltage arc protection at that point, but also enhances the structural strength of the end of the first sleeve 31 through the insertion part 332, which helps to maintain the overall shape.

[0049] Better, such as Figure 3 As shown, the first sleeve 31 covers the insulating outer sheath of both the first conductor 21 and the second conductor 22 in the direction of their exit.

[0050] Preferably, the second sleeve 32 covers the insulating outer sheath of the second conductor 22 in the lead-out direction of the second conductor 22, and the other end covers the root of the second pin 12 adjacent to the thermistor 10.

[0051] Preferably, the open end of the metal casing 40 extends into the first sleeve 31 and the second sleeve 32 in the direction of the lead-out of the first wire 21 and the second wire 22.

[0052] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-insulation, high-voltage-resistant temperature sensor, characterized in that, include: A thermistor is a two-ended device with a first pin and a second pin. A first wire is soldered to the first pin of the thermistor; A second wire is soldered to the second pin of the thermistor; A first sleeve made of polytetrafluoroethylene is used to house the thermistor, the connection between the first pin and the first wire, and the connection between the second pin and the second wire. The first wire and the second wire are led out side by side from the same end of the first sleeve. A second sleeve made of polytetrafluoroethylene is located inside the first sleeve and is used to fit the connection between the second pin and the second wire, so that the second pin and the second wire are insulated and isolated from the first pin and the first wire. A sleeve made of polytetrafluoroethylene is tightly fitted to the other end of the second sleeve relative to the lead-out ends of the first and second wires; A metal outer shell is a cylindrical structure fitted around the outside of the first sleeve with a clearance fit. One end of the shell is open to insert the first sleeve, while the other end is closed to block the plug. Furthermore, the metal casing is filled with epoxy resin from the open end to encapsulate and fix the internal thermistor, first sleeve, second sleeve, first wire, second wire, and plug.

2. The high-insulation, high-voltage-resistant temperature sensor as described in claim 1, characterized in that, The thermistor mentioned is a glass-sealed radial NTC thermistor, a glass-sealed diode-type NTC thermistor, or a thin-film platinum resistance thermometer.

3. The high-insulation, high-voltage-resistant temperature sensor as described in claim 1, characterized in that, The plug has a circular end with an outer diameter larger than that of the first sleeve, and one end of the circular end is coaxially formed to fit tightly into the insertion part of the first sleeve.

4. A high-insulation, high-voltage-resistant temperature sensor as described in claim 3, characterized in that, The connector is cylindrical.

5. A high-insulation, high-voltage-resistant temperature sensor as described in any one of claims 1 to 4, characterized in that, The first sleeve simultaneously covers the insulation sheaths of the first and second conductors in the direction of their exit.

6. A high-insulation, high-voltage-resistant temperature sensor as described in any one of claims 1 to 4, characterized in that, The second sleeve covers the insulating outer sheath of the second conductor in the direction of its lead-out, and the other end covers the root of the thermistor adjacent to the second pin.

7. A high-insulation, high-voltage-resistant temperature sensor as described in any one of claims 1 to 4, characterized in that, The open end of the metal casing extends into a first sleeve and a second sleeve in the direction of the lead-out of the first and second conductors.

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