Thermistor with high sensitivity and high insulativity and heat-sensitive sensor thereof

Abstract

The utility model relates to a thermistor with high sensitivity and high insulativity and a heat-sensitive sensor thereof, the thermistor comprises a heat-sensitive chip, two leads, a long glass shell and an insulating sleeve, the two leads are distributed in parallel, the two leads are connected with the heat-sensitive chip, the long glass shell is wrapped outside the two leads and the heat-sensitive chip, and the insulating sleeve is sleeved outside the long glass shell. The insulating sleeve is sleeved on the lower end surface of the long glass shell, and the thermosensitive chip is arranged at the upper end in the long glass shell and is positioned above the insulating sleeve. The thermistor is provided with the long glass shell, the insulating sleeve can be sleeved on the periphery of the lower end of the long glass shell, the insulativity and the high-voltage resistance of the thermistor are improved, the service life of the thermistor is prolonged, the upper end part of the long glass shell with the thermosensitive chip is exposed out of the insulating sleeve, and the temperature measurement sensitivity of the thermistor is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to thermal sensor technical field especially relates to a kind of thermistor with high sensitivity and high insulation and its thermal sensor. BACKGROUND

[0002] Household appliances such as coffee machine, water heater, electric kettle used in life all use thermistor or thermal sensor to measure temperature.The existing thermistor structure is mainly composed of thermosensitive chip, lead wire and metal shell, the lead wire is welded on the thermosensitive chip, then resin is used to encapsulate the lead wire and the outside of the thermosensitive chip, so as to form a protective layer on the lead wire and the outside of the thermosensitive chip, then the thermistor after primary encapsulation is inserted into the shell, and then epoxy resin is poured into the shell.

[0003] The existing thermistor has some deficiencies in the temperature measurement process:

[0004] 1) The protective layer is made of resin, and the resin is generally made of epoxy, phenolic, silicone and heat-conducting silicone grease, etc.The thermal conductivity of the protective layer made of resin is not high, and in the temperature sensing process of the thermistor, the thermosensitive chip needs to pass through multiple materials to transmit the correct temperature to the thermosensitive chip, which has poor thermal conductivity, increases the thermal reaction time, and has slow response speed, which is not conducive to the rapid arrival of heat to the core of the thermosensitive chip, resulting in that the thermistor cannot quickly measure the temperature of the measured object, and a long time is needed for temperature measurement.

[0005] 2) For high environmental application requirements, such as an environment with a withstand voltage of 500V, since the existing thermistor encapsulation structure is mainly a resin protective layer, the insulation effect is not strong enough, and the existing thermistor will be broken down when used in a 500V environment, resulting in damage to the thermistor, so that the existing thermistor cannot be used in a working environment with a withstand voltage of 500V or above, and the use range of the thermistor is limited. INVENTION CONTENTS

[0006] Therefore, it is necessary to provide a thermistor with a long glass shell, the long glass shell is set as a strip-shaped structure, an insulating sleeve is sleeved on the long glass shell, the insulation and high-voltage resistance of the thermistor are greatly improved, the thermistor is prevented from being damaged due to high-voltage breakdown, the upper end of the long glass shell with the thermosensitive chip is exposed to the insulating sleeve, the temperature can be quickly conducted to the thermosensitive chip only by lengthening the long glass shell, and the sensitivity of the thermistor in temperature measurement is improved.

[0007] In order to solve the above problems, the utility model adopts the following technical solutions:

[0008] On one hand, this utility model provides a thermistor with high sensitivity and high insulation. The thermistor includes a thermistor chip, two leads, a long glass shell, and an insulating sleeve. The two leads are distributed in parallel and connected to the thermistor chip. The long glass shell is wrapped around the two leads and the thermistor chip. The long glass shell is configured as a long strip structure. The insulating sleeve is fitted on the lower surface of the long glass shell. The thermistor chip is located at the upper end inside the long glass shell and above the insulating sleeve.

[0009] Furthermore, the length of the long glass shell is 5mm-8mm.

[0010] Furthermore, the two leads are designated as the first lead and the second lead, with the front ends of the first lead and the second lead respectively connected to the electrodes at both ends of the thermistor chip.

[0011] Furthermore, the thermistor includes a first wire and a second wire, one end of the first wire being connected to the rear end of the first lead, and one end of the second wire being connected to the rear end of the second lead.

[0012] Furthermore, the first and second leads are made of Dumex wire with a diameter of 0.1-0.3 mm.

[0013] Furthermore, the thermistor chip is an NTC thermistor chip.

[0014] On the other hand, the present invention provides a thermistor, which includes a thermistor and a temperature sensing probe housing, which is fixed to the outside of the thermistor.

[0015] Furthermore, the outer shell of the temperature sensing probe has a bullet-shaped structure.

[0016] The beneficial effects of this utility model are as follows:

[0017] This utility model relates to a thermistor comprising a thermistor chip, two leads, a long glass shell, and an insulating sleeve. The two leads are parallel to each other and connected to the thermistor chip. The long glass shell encloses the two leads and the thermistor chip. The insulating sleeve is fitted over the lower surface of the long glass shell. The thermistor chip is located inside the upper part of the long glass shell, above the insulating sleeve. This utility model uses a long, strip-shaped structure for the long glass shell, allowing the insulating sleeve to fit over the lower outer periphery of the long glass shell. This improves the insulation and high-voltage resistance of the thermistor, extending its service life. By exposing the upper part of the long glass shell containing the thermistor chip to the insulating sleeve, the thermistor can quickly conduct heat to the thermistor chip by passing through the long glass shell during temperature measurement, thus improving the sensitivity of the thermistor's temperature measurement. Attached Figure Description

[0018] Fig. 1 This is a structural diagram of the thermistor in Embodiment 1 of this utility model;

[0019] Fig. 2 This is a schematic diagram showing the relationship between the thermistor chip, leads, and long glass shell of this utility model.

[0020] Fig. 3 This is a schematic diagram of the structure of the thermal sensor of this utility model.

[0021] In the figure, there are thermistor 1, thermistor 11, thermistor chip 111, first lead 112, second lead 113, long glass shell 114, insulating sleeve 115, first wire 116, second wire 117, and temperature probe shell 12. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the scope of the utility model.

[0023] like Figs. 1-3As shown, Embodiment 1 of this utility model provides a thermistor 11 with high sensitivity and high insulation. The thermistor 11 includes a thermistor chip 111, two leads, a long glass shell 114, and an insulating sleeve 115. The two leads are distributed in parallel and connected to the thermistor chip 111. The long glass shell 114 is wrapped around the two leads and the thermistor chip 111. The insulating sleeve 115 is fitted on the lower surface of the long glass shell 114. The thermistor chip 111 is located at the upper end inside the long glass shell 114 and above the insulating sleeve 115. In a specific implementation, the long glass shell 114 of this utility model is an elongated glass head, and the thermistor chip 111 inside the long glass shell 114 is not wrapped by the insulating sleeve 115. The thermistor 11 of this invention is provided with a long glass shell 114, which is designed as a long strip structure. An insulating sleeve 115 can be fitted around the lower outer periphery of the long glass shell 114. The insulating sleeve 115 serves as insulation, greatly improving the insulation and high-voltage resistance of the thermistor 11, preventing damage caused by high-voltage breakdown. In high-temperature environments, this improves the reliability of the thermistor 11 and extends its service life. The upper part of the long glass shell containing the thermistor chip 111 is exposed to the insulating sleeve 115, allowing the thermistor 11 to quickly conduct heat to the thermistor chip 111 through the long glass shell 114 during temperature testing. The thermal conductivity of the long glass shell 114 is higher than that of the traditional resin protective layer, which helps to improve the thermal conductivity of the thermistor 11, thereby increasing the sensitivity of temperature measurement and resulting in a faster temperature response speed.

[0024] In other embodiments, the elongated glass shell 114 may also be configured in other shapes, such as an elliptical structure.

[0025] In practice, the length of the long glass shell 114 is set to 5mm-8mm.

[0026] In other embodiments, the insulating sleeve 115 may consist of a PVDF outer layer and an EVA inner layer, with the EVA inner layer located inside the PVDF outer layer.

[0027] The two leads of this invention are a first lead 112 and a second lead 112, which are parallel to each other. The front ends of the first lead 112 and the second lead 112 are respectively connected to the electrodes at both ends of the thermistor chip 111. In a specific implementation, the ends of the two leads connected to the thermistor chip 111 are enclosed in a long glass shell 114.

[0028] In this embodiment of the invention, the thermistor 11 includes a first wire 116 and a second wire 117. One end of the first wire 116 is connected to the rear end of the first lead 112, and one end of the second wire 117 is connected to the rear end of the second lead 112. Specifically, the first wire 116 and the rear end of the first lead 112 are connected by welding, and the second wire 117 and the rear end of the second lead 112 are connected by welding. The first wire 116 includes a first conductor core and a first conductor core insulation layer, with the first conductor core insulation layer covering the outside of the first conductor core. The second wire 117 includes a second conductor core and a second conductor core insulation layer, with the second conductor core insulation layer covering the outside of the second conductor core.

[0029] In other embodiments, a first heat-shrink tubing is provided to cover the connection between the first conductor 116 and the first lead 112, and a second heat-shrink tubing is provided to cover the connection between the second conductor 117 and the second lead 112. Using the first heat-shrink tubing to cover the connection between the first conductor 116 and the first lead 112, and using the second heat-shrink tubing to cover the connection between the second conductor 117 and the second lead 112, improves the strength of the connection between the lead and the conductor, and also provides insulation protection.

[0030] In specific implementation, the first lead 112 and the second lead 112 of this utility model are made of magnesium wire with a diameter of 0.1-0.3mm.

[0031] In other embodiments, the first lead 112 and the second lead 112 may also be made of platinum wire, gold wire, nickel wire, or iron-nickel alloy wire.

[0032] The thermistor chip 111 of this utility model is an NTC thermistor chip.

[0033] This invention also provides a thermistor 1, including a thermistor 11. The thermistor 1 further includes a temperature probe housing 12, which is fixed to the outside of the thermistor 11. The temperature probe housing 12 has a bullet-shaped structure. The temperature probe housing 12 can be made of a metal probe. The bullet-shaped structure allows the fluid temperature to be transferred to the thermistor chip 111 of the thermistor 11 more quickly, resulting in a very short heat conduction time during temperature measurement.

[0034] The thermal sensor 1 formed by encapsulating the thermistor and temperature probe shell of this utility model is compared with the response time of existing epoxy resin encapsulated thermal sensor products for measuring fluid temperature from room temperature to 100 degrees Celsius. The comparison results are shown in Table 1.

[0035] Table 1 compares the response time of the thermal sensor of this invention with that of existing epoxy resin-encapsulated thermal sensors for measuring the temperature of fluids at room temperature.

[0036]

[0037] Table 1

[0038] As shown in Table 1, the thermal time constant of epoxy resin-encapsulated temperature sensors in the prior art is generally 50-60 seconds, while the thermistor of this invention only requires 2-4 seconds. Therefore, it is evident that the thermistor of this invention, due to the temperature sensing area of ​​the thermistor chip 111 encased in the long glass shell 114, has higher thermal conductivity than existing thermistors.

[0039] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A thermistor with high sensitivity and high insulation, characterized in that: The thermistor includes a thermistor chip, two leads, a long glass shell, and an insulating sleeve. The two leads are parallel to each other and connected to the thermistor chip. The long glass shell is wrapped around the two leads and the thermistor chip. The long glass shell is configured as a long strip structure. The insulating sleeve is fitted on the lower surface of the long glass shell. The thermistor chip is located at the upper end inside the long glass shell and above the insulating sleeve.

2. The thermistor with high sensitivity and high insulation according to claim 1, characterized in that: The length of the long glass shell is 5mm-8mm.

3. The thermistor with high sensitivity and high insulation according to claim 1, characterized in that: The two leads are the first lead and the second lead, and the front ends of the first lead and the second lead are connected to the electrodes at both ends of the thermistor chip, respectively.

4. The thermistor with high sensitivity and high insulation according to claim 1, characterized in that: The thermistor includes a first wire and a second wire, one end of the first wire is connected to the rear end of the first lead, and one end of the second wire is connected to the rear end of the second lead.

5. The thermistor with high sensitivity and high insulation according to claim 3, characterized in that: The first and second leads are made of Dumex wire with a diameter of 0.1-0.3 mm.

6. The thermistor with high sensitivity and high insulation according to claim 1, characterized in that: The thermistor chip is an NTC thermistor chip.

7. A thermal sensor, characterized in that: The thermistor includes any one of claims 1-6, and the thermistor further includes a temperature sensing probe housing, which is fixed to the outside of the thermistor.

8. The thermistor according to claim 7, characterized in that: The outer shell of the temperature sensing probe has a bullet-shaped structure.

Images