High-temperature-resistant semi-naked packaging high-sensitivity temperature sensor

Abstract

The utility model discloses a kind of high-temperature-resistant semi-naked packaging high-sensitivity temperature sensor, including line terminal, tablet, spring, insulating sleeve, NTC thermistor element, PPS plastic shell and lead wire.The utility model is directly exposed in mounting hole by the temperature sensing head of NTC thermistor with semi-naked design, greatly reduce the thermal resistance brought by traditional thick layer packaging material, so that heat can be quickly conducted to temperature sensing element, thereby shorten the thermal response time, improve the sensitivity of measurement.

Description

Technical Field

[0001] This utility model belongs to the field of temperature sensor technology, and in particular relates to a high-temperature resistant, semi-exposed, highly sensitive temperature sensor. Background Technology

[0002] During the testing process, it is often necessary to measure the temperature of the surface of high-temperature objects. High-temperature adhesive is required for fixation and heat conduction. However, the thicker the encapsulation material, the lower the thermal conductivity. Temperature sensors used in such scenarios are usually fully encapsulated, that is, the temperature sensing element (such as NTC thermistor) is completely wrapped and fixed in a metal shell using high-temperature adhesive or encapsulation material. The thick encapsulation material layer forms a large thermal resistance, which slows down the transfer of heat from the measured surface to the sensing element, prolongs the thermal response time of the sensor, and reduces the measurement sensitivity and accuracy. Therefore, a high-temperature resistant semi-bare encapsulation high-sensitivity temperature sensor is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a high-temperature resistant, semi-exposed, highly sensitive temperature sensor to solve the problems mentioned in the background art.

[0004] A high-temperature resistant, semi-bare packaged, high-sensitivity temperature sensor, comprising: The PPS plastic housing is made of high-temperature resistant polyphenylene sulfide material, and one end of the housing has a mounting hole.

[0005] The NTC thermistor element has a glass-encapsulated temperature sensing head, which is partially exposed within the mounting hole of the PPS plastic housing.

[0006] An insulating sleeve is fitted over the leads of an NTC thermistor element.

[0007] The metal guide post is fitted outside the insulating sleeve and located inside the PPS plastic shell.

[0008] Springs and pressure plates are sequentially fitted onto the outside of the PPS plastic shell.

[0009] The NTC thermistor element has pins connected to leads, and the leads are connected to wire terminals.

[0010] Furthermore, a high-temperature resin encapsulation layer is filled into the inner cavity of the PPS plastic shell, solidifying and encapsulating the pin roots of the NTC thermistor element, part of the insulating sleeve, and the metal guide post into a single unit, forming an insulating and voltage-resistant structure.

[0011] Furthermore, the front end of the temperature sensing head of the NTC thermistor element is basically flush with or slightly protruding from the end end of the PPS plastic shell, forming a semi-exposed state.

[0012] Furthermore, one end of the spring is connected to the pressure plate, and the other end abuts against the shoulder or specific structure of the PPS plastic shell.

[0013] The beneficial effects of this utility model are: 1. This utility model adopts a semi-exposed design for the temperature sensing head of the NTC thermistor, which is directly exposed in the mounting hole. This greatly reduces the thermal resistance caused by traditional thick-layer encapsulation materials, allowing heat to be quickly conducted to the temperature sensing element, thereby shortening the thermal response time and improving the measurement sensitivity.

[0014] 2. This utility model uses springs and pressure plates set on the outside of the PPS plastic shell. During installation, the spring force can be used to ensure that the temperature sensing head is always tightly and reliably attached to the surface being measured. This not only makes installation simple and quick, but also effectively reduces contact thermal resistance and can adapt to a certain degree of surface unevenness. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the high-temperature resistant semi-bare packaged high-sensitivity temperature sensor of this utility model; Figure 2 This is a side view of the three-dimensional structure of the tablet compression. Figure 3 This is a schematic diagram of the first exploded three-dimensional structure of the high-temperature resistant semi-bare packaged high-sensitivity temperature sensor of this utility model; Figure 4 This is a side view of the three-dimensional structure of the lead wire.

[0016] In the diagram, 1-line terminal, 2-pressure plate, 3-spring, 4-insulating sleeve, 5-NTC thermistor element, 6-PPS plastic shell, 7-lead wire. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0018] like Figures 1 to 4 The high-temperature resistant, semi-exposed, high-sensitivity temperature sensor of this invention, as shown, includes a line terminal 1, a pressure plate 2, a spring 3, an insulating sleeve 4, an NTC thermistor element 5, a PPS plastic shell 6, and leads 7.

[0019] The PPS plastic shell 6 is made of high-temperature resistant polyphenylene sulfide material through injection molding, and its front end is machined with a precise mounting hole.

[0020] The NTC thermistor element 5 consists of a temperature sensing head and pins. The temperature sensing head is made of glass and is placed inside the mounting hole. Its front end face is basically flush with the end face of the PPS plastic shell 6, thus achieving a semi-exposed state and contacting the surface being measured in the most optimized way.

[0021] The NTC thermistor element 2 has an insulating sleeve 4 on its pins. The insulating sleeve 4 is made of high-temperature ceramic tube or special plastic tube. The pins and the insulating sleeve 4 pass through the inner cavity of the PPS plastic shell 6.

[0022] The insulating sleeve 4 is fitted with a metal guide post, which serves as an auxiliary support and positioning element.

[0023] High-temperature epoxy resin or silicone resin is injected into the inner cavity of the PPS plastic shell 6 to form a high-temperature resin encapsulation layer. The encapsulation layer firmly encapsulates and solidifies the pin roots of the NTC thermistor element 2, most of the insulating sleeve 4, and the metal post inside the PPS plastic shell 6, forming a robust core structure with high insulation and withstand voltage performance.

[0024] On the outside of the PPS plastic housing 6, spring 3 and pressure plate 2 are sequentially fitted. One end of spring 3 rests on pressure plate 2, and the other end rests on a shoulder structure in the middle of PPS plastic housing 6. When the sensor is installed in the mounting hole of the device under test through pressure plate 2, spring 3 is compressed, and the resulting elastic force continuously pulls the entire sensor backward, so that the semi-exposed temperature sensing head is pressed tightly against the surface under test, ensuring good thermal contact.

[0025] The NTC thermistor element has 5 pins connected to leads, and the leads are connected to wire terminals.

[0026] The working principle of this utility model is as follows: The core component of this sensor is an NTC thermistor element temperature sensing head. The temperature sensing head has a highly sensitive temperature characteristic, and its resistance value decreases as the temperature rises. The NTC thermistor element is partially exposed and installed in the reserved hole in the PPS plastic shell, so that the temperature sensing head can directly or almost directly contact the surface being measured. This semi-exposed design reduces the thermal resistance of traditional thick-layer encapsulation materials and significantly improves the thermal conduction efficiency, thereby achieving a fast thermal response time.

[0027] By injecting high-temperature epoxy resin into the inner cavity of the PPS plastic shell to form a high-temperature resin encapsulation layer, an insulating and voltage-resistant layer is formed. This ensures electrical insulation between the pins and the shell, while also providing mechanical support and thermal stability. The high-temperature epoxy resin ensures that the encapsulation material does not degrade even when the surface of the heating element is instantly heated in a high-temperature environment, thus maintaining the long-term reliability of the sensor.

[0028] The PPS plastic housing is equipped with springs and pressure plates. The springs provide a certain amount of elasticity, allowing the sensor to fit tightly against the surface being measured during installation, reducing thermal contact resistance and adapting to uneven surfaces or vibrating environments. The pressure plates are used to fix the sensor position, ensuring convenient installation and stability, thereby improving assembly efficiency.

[0029] When this sensor comes into contact with a high-temperature surface, heat is rapidly conducted through the semi-exposed temperature-sensing head to the thermistor element, causing a change in its resistance value. This change is transmitted through the pins to the external measurement circuit and converted into a temperature reading. The PPS plastic housing provides high-temperature resistance (typically above 150°C) and high-voltage resistance (electrical insulation strength) protection, ensuring that the sensor works stably in harsh environments.

[0030] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-temperature resistant, semi-exposed, highly sensitive temperature sensor, characterized in that: High-temperature resistant semi-bare packaged high-sensitivity temperature sensors include PPS plastic shell, with mounting holes at one end; The NTC thermistor element has its temperature sensing head exposed inside the mounting hole. An insulating sleeve is fitted over the leads of an NTC thermistor element. Metal guide posts are fitted outside the insulating sleeve and located inside the PPS plastic shell; Springs and pressure plates are sequentially fitted onto the outside of the PPS plastic shell; The NTC thermistor element has pins connected to leads, and the leads are connected to wire terminals.

2. The high-temperature resistant semi-bare packaged high-sensitivity temperature sensor according to claim 1, characterized in that: A high-temperature resin encapsulation layer is filled into the inner cavity of the PPS plastic shell, and the pin roots of the NTC thermistor element and the insulating sleeve are cured and encapsulated in the PPS plastic shell.

3. The high-temperature resistant semi-bare packaged high-sensitivity temperature sensor according to claim 1, characterized in that: The temperature sensing head of the NTC thermistor element is a glass-encapsulated structure.

4. The high-temperature resistant semi-bare packaged high-sensitivity temperature sensor according to claim 1 or 2, characterized in that: The front end of the temperature sensing head is flush with or slightly protruding from the end of the PPS plastic shell.

5. The high-temperature resistant semi-bare packaged high-sensitivity temperature sensor according to claim 1, characterized in that: The insulating sleeve is a high-temperature ceramic sleeve or a high-temperature resistant plastic sleeve.

Images