Temperature sensing assembly based on combination of metals with different thermal expansion coefficients

Abstract

The invention relates to a temperature sensing assembly based on combination of metals with different thermal expansion coefficients, which comprises an outer cylinder, a working rod and a bottom ring, the working rod extends into the outer cylinder, the bottom ring is arranged at the bottom of the outer cylinder, and the working rod is sleeved with the bottom ring; the bottom ring and the outer side wall of the working rod are assembled in a clearance fit mode, the bottom ring and the inner side wall of the outer cylinder are assembled in a clearance fit mode, the bottom ring, the working rod and the outer cylinder are welded and fixed in a high-frequency welding mode, the outer cylinder is made of 0Cr18Ni9 stainless steel with the linear expansion coefficient being (17.2-17.7) * 10 <-6 > / DEG C, the working rod is made of 4J36 low-expansion alloy, and the working rod is made of 4J36 low-expansion alloy. The linear expansion coefficient of the 4J36 low-expansion alloy adopted by the working rod is smaller than 1.5 * 10 <-6 > / DEG C within the range of 20-300 DEG C, the bottom ring is made of 0Cr18Ni9 stainless steel, and in a word, the working rod has the advantages of being high in precision, good in stability, excellent in durability and low in production cost.

Description

Technical Field

[0001] The invention relates to the technical field of temperature sensors, in particular to a temperature sensing component based on a combination of metals with different thermal expansion coefficients. Background Art

[0002] Temperature sensors are very important temperature sensing components in precision instruments, electronic equipment, aerospace, military equipment and other automated control systems in high temperature environments. Temperature sensors often have problems such as insufficient sensitivity, slow response and poor reliability in high temperature or extreme temperature difference environments. Especially in high temperature environments, due to the large thermal expansion coefficient of the material, the size change of the sensor can easily lead to measurement errors or sensor failure. The existing processing methods generally adopt more complex structures and add more temperature sensing components, which not only fails to solve the problem, but also increases the cost of the temperature sensor and affects the use of the sensor.

[0003] Another more conventional approach is to use a bimetallic or multi-metallic alloy combination design, using the difference in thermal expansion coefficients of different metal materials to produce detectable displacement when the temperature changes. However, some current temperature sensors based on bimetallic alloys have the following problems: first, the selection range of bimetallic materials is limited, and the expansion difference of the materials is not significant enough to meet the requirements of high-precision measurement. Secondly, existing temperature sensing components mostly use simple material ratios, which fail to give full play to the performance advantages of different metal alloys, resulting in slow response speed, short life, and poor adaptability to ambient temperature of the sensor. Therefore, a temperature sensing component based on a combination of metals with different thermal expansion coefficients is needed to solve the above-mentioned problems of low accuracy, poor stability, and insufficient durability. Summary of the invention

[0004] In view of this, the present invention proposes a temperature sensing component based on a combination of metals with different thermal expansion coefficients, which is applied to the field of temperature sensor technology to solve the existing technical problems of low accuracy, poor stability, insufficient durability and high cost.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A temperature sensing component based on a combination of metals with different thermal expansion coefficients comprises an outer cylinder, a working rod and a bottom ring. The working rod extends into the interior of the outer cylinder, the bottom ring is arranged at the bottom of the outer cylinder, the bottom ring is sleeved on the working rod, the outer side wall of the bottom ring and the working rod and the inner side wall of the outer cylinder are assembled in a clearance fit manner, the bottom ring, the working rod and the outer cylinder are welded and fixed in a high-frequency welding manner, the outer cylinder is made of 0Cr18Ni9 stainless steel with a linear expansion coefficient of (17.2-17.7)×10-6 / °C, the working rod is made of 4J36 low expansion alloy, the linear expansion coefficient of the 4J36 low expansion alloy used in the working rod is less than 1.5×10-6 / °C within the range of 20°C to 300°C, and the bottom ring is made of 0Cr18Ni9 stainless steel.

[0007] Furthermore, the outer cylinder and the working rod undergo displacement changes under the same temperature change, and the displacement changes of the outer cylinder and the working rod are detected by an automatic control element.

[0008] Furthermore, the automatic control element detects the displacement change between the outer cylinder and the working rod with a displacement output accuracy of ±0.005.

[0009] Furthermore, the automatic control element adopts a constant temperature oil tank and a detection tooling, the outer cylinder extends into the constant temperature oil tank, the detection tooling includes a product fixture, a meter stand and a micrometer, the product fixture is connected to the top of the outer cylinder, the meter stand supports the bottom of the micrometer, and the detection end of the micrometer extends downward into the interior of the outer cylinder to detect the displacement change of the outer cylinder and the working rod.

[0010] The present invention has the following beneficial effects:

[0011] 1. The temperature sensing component based on the combination of metals with different thermal expansion coefficients mentioned in the present invention is assembled by combining stainless steel and low expansion coefficient alloy 4J36 and then welded by high-frequency welding. In actual work, the outer cylinder and the working rod will produce axial expansion and contraction as the temperature rises due to their different thermal expansion coefficients. Since the expansion of the outer cylinder is large and the expansion of the working rod is small, the displacement generated by the expansion difference between the two can be converted into a temperature change signal. It not only has good stability, but also has a very low production cost, which is convenient for large-scale promotion. Through linkage with automatic control elements, automatic detection and adjustment of temperature can be realized, and the displacement output accuracy reaches ±0.005, which has the advantage of high-precision temperature sensing.

[0012] 2. The present invention mentions a temperature sensing component based on a combination of metals with different thermal expansion coefficients. The outer cylinder is made of 0Cr18Ni9 stainless steel. This material has good corrosion resistance, heat resistance, low-temperature strength and mechanical properties. It can ensure high plasticity and toughness at low temperature, room temperature and high temperature, and ensure the stability of the outer cylinder under temperature changes. The bottom ring is made of 0Cr18Ni9 stainless steel, which serves as the fixed part of the temperature sensing component and completes the temperature sensing structure together with the working rod and the outer cylinder. While ensuring the firmness of the welding, it improves the mechanical stability of the component.

[0013] 3. The present invention mentions a temperature sensing component based on a combination of metals with different thermal expansion coefficients. The working rod adopts 4J36 low expansion alloy. The alloy has a low expansion coefficient, which is better than most conventional metal materials, and has good machinability and mechanical properties. It is widely used in the manufacture of precision instruments, meters, standard measuring tools, microwave resonant cavities and bimetallic wave layers. Its linear expansion coefficient is less than 1.5×10-6 / ℃ in the range of 20℃ to 300℃, which ensures that the size of the working rod changes little when the ambient temperature changes, and can ensure that the size of the component is nearly constant, thereby ensuring the accuracy of the displacement signal caused by temperature changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of the structure of a temperature sensing component based on a combination of metals with different thermal expansion coefficients provided by the present invention;

[0016] Figure 2 It is a three-dimensional appearance diagram of the outer cylinder in a specific embodiment of the present invention;

[0017] Figure 3 It is a structural schematic diagram of an automatic control element in a specific embodiment of the present invention;

[0018] Among them: 1. Outer cylinder; 2. Working rod; 3. Bottom ring; 4. Product fixture; 5. Table stand; 6. Micrometer. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0021] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present invention, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any of the several aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0022] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the form, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0023] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0024] Example 1

[0025] like Figure 1 and Figure 2As shown, a temperature sensing component based on a combination of metals with different thermal expansion coefficients includes an outer cylinder 1, a working rod 2 and a bottom ring 3. The working rod 2 extends into the interior of the outer cylinder, the bottom ring 3 is arranged at the bottom of the outer cylinder 1, and the bottom ring 3 is sleeved on the working rod 2. The outer side wall of the bottom ring 3 and the working rod 2 and the inner side wall of the outer cylinder 1 are assembled by clearance fitting. The bottom ring 3, the working rod 2 and the outer cylinder 1 are welded and fixed by high-frequency welding. The outer cylinder 1 adopts 0Cr18Ni9 stainless steel with a linear expansion coefficient of (17.2~17.7)×10-6 / ℃, the working rod 2 adopts 4J36 low expansion alloy, and the linear expansion coefficient of the 4J36 low expansion alloy adopted by the working rod 2 is less than 1.5×10-6 / ℃ in the range of 20℃ to 300℃, and the bottom ring 3 adopts 0Cr18Ni9 stainless steel.

[0026] The outer cylinder 1 and the working rod 2 undergo displacement changes under the same temperature change to achieve the change of the working state of the corresponding control mechanism. The displacement changes of the outer cylinder 1 and the working rod 2 are detected by the automatic control element. The displacement changes reflect the temperature changes by detecting the displacement changes, thereby outputting a temperature change signal. The displacement output accuracy of the displacement change between the outer cylinder 1 and the working rod 2 detected by the automatic control element is within ±0.005. The automatic control element adopts a constant temperature oil tank and a detection tool. The outer cylinder 1 goes deep into the constant temperature oil tank. The detection tool includes a product fixture 4, a table frame 5 and a micrometer 6. The product fixture 4 is connected to the top of the outer cylinder 1. The table frame 5 supports the bottom of the micrometer 6. The detection end of the micrometer 6 extends downward into the interior of the outer cylinder 1 to detect the displacement changes of the outer cylinder 1 and the working rod 2. The control mechanism in this embodiment is a micrometer 6.

[0027] In this embodiment, the temperature requirement is within the temperature range of 95°C to 260°C. The displacement of the working rod 2 in the temperature sensing component in the contraction direction is calculated as follows:

[0028] S1. Temperature displacement performance of temperature sensing components in calculation:

[0029] When heated from 95°C to 260°C, the temperature displacement of the temperature sensing component shrinks by about 0.3mm.

[0030] S2. Calculation of expansion of outer cylinder 1:

[0031] The material of the outer cylinder 1 is 0Cr18Ni9 stainless steel, and the linear expansion coefficient is: (17.2~17.7)*10-6 / ℃, then when the length is 125mm and the temperature difference is 165℃, the length change is 17.4×10-6×125×165=0.3589mm;

[0032] S3. Calculation of expansion of working rod 2:

[0033] The working rod 2 is made of 4J36 low expansion alloy with an expansion coefficient of 1.5*10-6 / ℃. When the length is 132mm and the temperature difference is 165℃, the length change is 1.5×10-6×132×165=0.0327mm;

[0034] S4. Calculation of expansion after combination

[0035] The outer cylinder 1 and the working rod 2 are welded together. When the temperature difference is 165°C, the displacement difference between the two is 0.3589mm-0.0327mm=0.3263mm, which is within the range of 0.3±0.005.

[0036] The present invention mentions a temperature sensing component based on a combination of metals with different thermal expansion coefficients, which is assembled by combining stainless steel and low expansion coefficient alloy 4J36 and then welded by high-frequency welding. It can realize automatic detection and adjustment of temperature through linkage with automatic control elements. By reasonably selecting metal materials and optimizing processes, the displacement output accuracy reaches ±0.005. In short, the present invention has the advantages of high precision, good stability, excellent durability and low production cost.

[0037] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A temperature sensing component based on a combination of metals with different thermal expansion coefficients, characterized in that: The invention comprises an outer cylinder (1), a working rod (2) and a bottom ring (3), wherein the working rod (2) extends into the interior of the outer cylinder, the bottom ring (3) is arranged at the bottom of the outer cylinder (1), and the bottom ring (3) is sleeved on the working rod (2). The outer side wall of the bottom ring (3) and the inner side wall of the outer cylinder (1) are assembled by clearance fitting, and the bottom ring (3) and the working rod (2) and the outer cylinder (1) are welded and fixed by high-frequency welding. The outer cylinder (1) is made of 0Cr18Ni9 stainless steel with a linear expansion coefficient of (17.2 to 17.7)×10-6 / °C, the working rod (2) is made of 4J36 low expansion alloy, and the linear expansion coefficient of the 4J36 low expansion alloy used by the working rod (2) is less than 1.5×10-6 / °C within the range of 20°C to 300°C, and the bottom ring (3) is made of 0Cr18Ni9 stainless steel.

2. A temperature sensing component based on a combination of metals with different thermal expansion coefficients according to claim 1, characterized in that: The outer cylinder (1) and the working rod (2) undergo displacement changes under the same temperature change, and the displacement changes of the outer cylinder (1) and the working rod (2) are detected by an automatic control element.

3. A temperature sensing component based on a combination of metals with different thermal expansion coefficients according to claim 2, characterized in that: The automatic control element detects the displacement change between the outer cylinder (1) and the working rod (2) with a displacement output accuracy of ±0.

005.

4. A temperature sensing component based on a combination of metals with different thermal expansion coefficients according to claim 3, characterized in that: The automatic control element adopts a constant temperature oil tank and a detection tool, and the outer cylinder (1) penetrates into the constant temperature oil tank.

5. A temperature sensing component based on a combination of metals with different thermal expansion coefficients according to claim 4, characterized in that: The inspection tool comprises a product fixture (4), a gauge stand (5) and a micrometer (6); the product fixture (4) is connected to the top of the outer cylinder (1), and the gauge stand (5) supports the bottom of the micrometer (6).

6. A temperature sensing component based on a combination of metals with different thermal expansion coefficients according to claim 5, characterized in that: The detection end of the micrometer (6) extends downward into the interior of the outer cylinder (1) to detect the displacement change of the outer cylinder (1) and the working rod (2).

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