Low-temperature temperature sensor mounting assembly and mounting method

Abstract

The invention relates to the technical field of sensors, in particular to a low-temperature temperature sensor mounting assembly and a mounting method.The low-temperature temperature sensor mounting assembly comprises a fixed base fixed to a to-be-measured temperature surface, a positioning hole penetrating through the fixed base is formed in the fixed base, and a sensor package penetrates through the positioning hole and then makes contact with the to-be-measured temperature surface; the fixed base is provided with a pressing assembly which applies pressing force to the sensor package along the direction of a vertical temperature surface to be measured. The shielding cover covers the surface of the fixed base, and an anti-radiation shielding space is defined by the shielding cover and the fixed base; and after the lead wire of the sensor package passes through the shielding case, one end outside the shielding case is subjected to heat sink treatment through the heat sink plate, and the other end outside the shielding case is subjected to heat sink around the heat sink stud and then is connected with the signal collector. According to the invention, the measurement precision of the low-temperature sensor is greatly improved, and the interference of an electromagnetic field is shielded.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, specifically to a low-temperature temperature sensor mounting assembly and mounting method. Background Technology

[0002] Cryogenic technology is widely used in cutting-edge fields such as quantum computing dilution refrigerators, cryogenic vacuum systems for controlled nuclear fusion devices, cryogenic superconducting magnets, cryogenic fluid transport such as liquid hydrogen, and deep space environment simulation. In these systems, temperature is one of the most critical parameters characterizing their operating status and ensuring their safety and efficiency, making real-time and accurate temperature monitoring of key locations essential. However, these large scientific facilities and extreme environment systems often experience strong interference fields and complex thermal loads during operation, posing a severe challenge to the accuracy and reliability of cryogenic temperature measurements. Because the temperature in the cryogenic region is extremely low, any tiny additional heat input can lead to significant temperature rise errors. Existing measurement systems generally face multiple external heat sources of interference, such as axial heat flow introduced from the ambient temperature environment along the sensor leads and support structure, direct thermal radiation from surrounding high-temperature surfaces to the cryogenic sensor, Joule heating generated by the resistance of long-distance leads and the measurement current itself, convective heat transfer to the sensor by residual gas molecules under non-ideal vacuum, and direct energy deposition caused by scattered electrons and secondary particles induced by the experimental beam. Due to the inability to effectively isolate the thermal load, incorrect installation often introduces measurement errors or even erroneous results. The sensor readings often deviate significantly from the true temperature of the measured point, resulting in large measurement errors. Under external interference, signal drift is prone to occur, requiring frequent interruptions of experiments for recalibration, which seriously affects the measurement accuracy of cryogenic sensors. Therefore, this problem urgently needs to be solved. Summary of the Invention

[0003] To avoid and overcome the technical problems existing in the prior art, the present invention provides a low-temperature temperature sensor mounting assembly and mounting method. The present invention significantly improves the measurement accuracy of the low-temperature sensor and shields against electromagnetic interference.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A low-temperature temperature sensor mounting assembly includes a fixed base fixed to the surface of the temperature to be measured. The fixed base has a positioning hole that penetrates the fixed base. The sensor package passes through the positioning hole and contacts the surface of the temperature to be measured. The fixed base is provided with a clamping component that applies a clamping force to the sensor package along the vertical direction of the surface of the temperature to be measured. A shielding cover is placed on the surface of the fixed base, forming a radiation-proof shielding space with the fixed base. After the lead wire of the sensor package passes through the shielding cover, one end outside the shielding cover is heat-sinked by a heat sink plate, and the other end outside the shielding cover is heat-sinked by a heat sink stud and then connected to a signal acquisition device.

[0005] As a further aspect of the present invention: the clamping assembly includes a rotating arm that rotates in conjunction with a fixed base, the rotation axis of the rotating arm and the fixed base being arranged vertically to the surface to be measured; a clamping stud is installed on the rotating arm along a direction parallel to the rotation axis, and when the clamping stud moves with the rotating arm to a position corresponding to the vertical position of the sensor package, the clamping nut engages with the rotating arm threadedly and moves up and down to apply a clamping force to the sensor package.

[0006] As a further embodiment of the present invention: the lead wire is a four-wire lead wire, and the shielding cover has corresponding lead wire holes for the lead wire to pass through.

[0007] As a further embodiment of the present invention: the shielding cover includes a cover body placed on the fixed base and a cover body at one end away from the fixed base. The cover body of the shielding cover has a cubic structure, and the cover body of the shielding cover is a V-shaped cover plate with an opening facing the sensor packaging side. The angle of the V-shaped cover plate is 80° to 84°.

[0008] As a further aspect of the present invention: the material of the fixed base and the surface to be measured is the same; Alternatively, the thermal shrinkage rate between the fixed base and the surface to be measured is less than twice.

[0009] As a further aspect of the present invention: the heat sink plate is made of alloy material, the temperature of the fixed surface of the heat sink plate is the same as the temperature of the surface to be measured, and when the lead wire passes through the heat sink plate, the lead wire is wrapped by the alloy of the heat sink plate to cool down.

[0010] A method for installing a low-temperature temperature sensor mounting assembly, characterized by comprising the following steps: S1. Determine the thickness of the shielding cover based on the required shielding effectiveness, and then manufacture the shielding cover; S2. Calculate the shortest length of the heat sink plate and make the corresponding heat sink plate for the lead wire to pass through; S3. Apply low-temperature adhesive to the mounting surfaces of the heat sink plate and the fixing base, and install the heat sink plate, the fixing base and the heat sink studs. S4. After applying low-temperature adhesive to the bottom of the sensor package, place it into the positioning hole so that it fits against the surface to be measured, and press the sensor package tightly with the clamping stud. S5. Install the shielding cover and lead out the sensor's encapsulated leads, passing them through the heat sink plate and around the heat sink studs before connecting them to the signal acquisition unit to collect temperature parameters.

[0011] As a further aspect of the present invention: when the lead wire passes through the heat sink plate, the alloy layer of the heat sink plate forms a wrapping area coaxial with the lead wire. T The temperature of the alloy layer of the heat sink plate; the diameter of the area where the heat sink plate wraps around the lead wire is... D The diameter of the lead wire is d Then the shortest length of the heat sink plate for: when 80k > T > 4.5k hour:

[0012] when 4.5k ≥ T > 1.5k ,and ≥ hour:

[0013] when 4.5k ≥ T > 1.5k ,and < hour: .

[0014] As a further aspect of the present invention: the shielding effectiveness of the shielding cover is :

[0015] in, t The thickness of the shielding cover; f The frequency of the electromagnetic waves outside the shielding cover; The magnetic permeability of the shielding cover; denoted as the conductivity of the shielding cover.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The sensor package of this invention contacts the surface to be measured and applies an adjustable vertical clamping force through a clamping stud. Combined with pre-fixation with low-temperature adhesive, it ensures that the sensing end face is tightly attached to the surface to be measured, reducing contact thermal resistance. At the same time, the shielding cover and the fixing base form a closed shielding space, effectively blocking the influence of external environmental heat radiation on the sensor package and significantly reducing the measurement error introduced by radiative heat. For the leads of the sensor package leading out of the shielding cover, the leads are wrapped with heat sink plates for heat sink treatment. Combined with the winding design of the heat sink stud, the parasitic heat transmitted by the leads is effectively conducted away, reducing the interference of lead heat leakage on low-temperature measurement. Both ends of the leads are heat-sinked by heat sink plates and heat sink studs, respectively, which greatly improves the measurement accuracy of the low-temperature sensor.

[0017] 2. This invention controls the materials of the fixing base and the clamping component to make them consistent with the material of the surface to be tested or to control the thermal shrinkage rate, thereby avoiding the breakage of the screws of the fixing base and the loosening of the structure of the clamping component due to low temperature shrinkage, and ensuring that the overall structure can be reliably fixed for a long time in low temperature environment; the combination of the rotating arm and the clamping stud realizes two-point adjustable clamping, which avoids the problem of easy breakage of direct bolt fixing and overcomes the disadvantage of weak fixing by simple adhesive, adapting to different packaging sizes and installation conditions.

[0018] 3. The split structure of the shielding cover of this invention makes it easy to seal after the sensor is installed, and the V-shaped cover angle can achieve the best shielding effect; the lead wire adopts a four-wire connection, which can effectively eliminate the error introduced by thermoelectric potential.

[0019] 4. This invention provides corresponding calculation formulas for the minimum length of the heat sink plate for different temperature ranges. The heat sink plate removes most of the heat from the outside, avoiding the impact of external heat on the measurement accuracy of the sensor. At the same time, the thickness of the shielding cover is determined according to the shielding effectiveness formula, so that the structure can meet the shielding requirements under the corresponding conditions. In addition, the shielding effectiveness of the device is calculated in conjunction with the structural design of the shielding device. The thickness parameter of the shielding cover can be determined according to the shielding effectiveness formula based on the installation situation, so that the structure can meet the electromagnetic shielding requirements under the corresponding conditions.

[0020] 5. This invention solves the problems of poor accuracy and large errors caused by factors such as lead wire heat conduction, lead wire self-heating, and environmental heat radiation during the measurement process, as well as the inability to replace damaged sensors or the difficulty in replacement and high disassembly and assembly costs. It avoids the problem of sensor not being firmly attached and the mechanical fixing structure breaking at low temperatures due to physical properties. It provides full protection during the low temperature signal acquisition process, greatly improves the accuracy of low temperature measurement, increases the measurement response time, increases the thermal contact between the sensor and the target object, and the modular structure facilitates installation. It also reduces the replacement cost of the temperature measurement device, saves maintenance time, and greatly improves the overall efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a structural schematic diagram of the front of the fixing base of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the back of the fixing base of the present invention.

[0024] Figure 4 This is a schematic diagram showing the fit between the lead wire and the heat sink plate in this invention.

[0025] In the picture: 1. Fixed base; 11. Clamping assembly; 111. Rotating arm; 112. Clamping stud; 12. Positioning hole; 2. Shielding cover; 21. Shielding cover plate; 3. Heat sink plate; 4. Lead wire; 5. Heat sink stud; 6. Sensor package. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1-4 In this embodiment of the invention, a low-temperature temperature sensor mounting assembly and mounting method includes a fixed base 1, which is directly fixed to the surface to be measured by positioning screws. The fixed base 1 is arranged in close contact with the surface to be measured, and a positioning hole 12 is provided on its contact surface, which passes through the positioning base 1. After the low-temperature sensor is encapsulated, the sensor package 6 formed by the encapsulation passes through the positioning hole 12, and its temperature sensing end face is in direct contact with the surface to be measured.

[0028] With the contact surface between the fixed base 1 and the surface to be measured as the front, a clamping assembly 11 is provided on the back of the fixed base 1. The clamping assembly 11 applies an adjustable clamping force to the sensor package 6 in a direction perpendicular to the surface to be measured. To avoid bolt breakage when the sensor package 6 is directly fixed to the surface to be measured by bolts, and to avoid insecure fixing when the sensor package 6 is directly fixed by adhesive, a rotating arm 111 is provided on the fixed base 1 in this embodiment. The rotating arm 111 is rotatably engaged with the fixed base 1 through a shaft hole connection, and the axis of rotation is perpendicular to the surface to be measured. A clamping stud 112 is installed at the end of the rotating arm 111 away from the rotating end, and the axis of the clamping stud 112 is perpendicular to the surface to be measured. When the rotating arm 111 rotates, causing the clamping stud 112 to move to a position corresponding to the vertical position of the sensor package 6, the clamping stud 112 can be driven to move up and down along its axis by screwing on the clamping stud 112, thereby applying a controllable vertical clamping force to the sensor package 6 and pressing the sensor package 6 onto the surface to be measured. The contact surface between the sensor package 6 and the surface to be measured is pre-coated with low-temperature adhesive, and pre-adhesion and fixation are achieved by the low-temperature adhesive.

[0029] A shielding cover 2 is disposed on the back of the fixed base 1. Its material can be the same as that of the fixed base 1. The shielding cover 2 and the fixed base 1 enclose a closed shielding space, enclosing the sensor package 6 inside. The shielding space blocks heat radiation from the external environment, preventing direct radiant heat from irradiating the sensor package 6 and introducing measurement errors. The shielding cover 2 can be a split design, with a cubic structure. Its two opposite sides extend upwards to form a V-shaped surface for the V-shaped cover plate to mate with. In this embodiment, the shielding cover 2 can be integrally fixed to the fixed base 1, while the V-shaped cover plate is separately fixed to the cover. After the sensor package 6 is fixed, the V-shaped cover plate is then bonded to the cover using a low-temperature adhesive with good thermal conductivity. The open end of the V-shaped cover plate faces the sensor package 6, and its preferred V-angle is 82°.

[0030] Regarding the material selection, the overall material of the fixing base 1 (including the clamping assembly 11) is consistent with that of the surface to be measured, or the thermal shrinkage rate of the surface to be measured is less than 2 times that of the surface to be measured, to prevent excessive thermal shrinkage when the room temperature drops to a low temperature, which could cause the positioning screws of the fixing base 1 to break. The material of the clamping stud 112 is consistent with that of the surface to be measured, or the thermal shrinkage rate of the surface to be measured is less than 1.5 times that of the surface to be measured.

[0031] In this embodiment, two sets of clamping components are selected and symmetrically arranged on both sides of the sensor package 6 to achieve two-point clamping and fixing of the sensor package 6. The shield 2 has lead wire holes on its cover for the lead wires 4 of the sensor package 6 to be led outward. After being heat-sinked by the heat sink plate 3, the lead wires 4 are wound around the heat sink studs 5 and then connected to the signal acquisition device.

[0032] The heat sink stud 5 is used to heat sink the lead 4. If the lead is introduced directly from room temperature, the lead 4 needs to be wrapped around the heat sink stud 5 six times. If it passes through a liquid nitrogen radiation shielding layer, the lead 4 only needs to be wrapped around the heat sink stud 5 three to four times. The lead 4 uses a four-wire system, which helps to eliminate errors caused by thermoelectric potential and other factors in the low-temperature measurement environment.

[0033] The heat sink plate 3 is made of metal, preferably tin in this embodiment. The lead wire 4 travels along the heat sink plate 3, and the low-temperature tin of the heat sink plate 3 completely encapsulates the lead wire 4, heat-sinking it. The heat sink plate 3 is preferably fixed to the surface to be measured using low-temperature adhesive, fitting snugly against the fixing base 1, and as close as possible to the lead wire outlet on the shielding cover 2. In actual use, the heat absorbed by the exposed section of the lead wire 4 between the heat sink plate 3 and the shielding cover 2 is negligible. The two ends of the lead wire 4 located outside the shielding cover 2 are heat-sinked by the heat sink plate 3 and the heat sink studs 5, thereby avoiding interference from external heat. The leads 4 are arranged at equal intervals on the heat sink plate 11. The lead wire 4 travels along the surface of the heat sink plate 3, and when encapsulated by tin, the tin forms a ring-shaped encapsulation layer on the outer layer of the lead wire 4. In this embodiment, the lead wire 4 is typically made of copper wire.

[0034] The installation of a low-temperature temperature sensor mounting assembly includes the following steps: S1. Determine the thickness of shielding cover 2 according to the required shielding effectiveness, and manufacture shielding cover 2; The shielding effectiveness of shielding cover 2 is :

[0035] in, t The thickness of shielding cover 2; f The frequency of the electromagnetic waves outside the shielding cover; The magnetic permeability of the shielding cover; denoted as the conductivity of the shielding cover.

[0036] S2. Calculate the shortest length of the heat sink plate 3, and fabricate the corresponding heat sink plate 3 for the lead wire 4 to pass through; when the lead wire 4 passes through the heat sink plate 3, the heat sink plate 3 forms a ring-shaped wrapping area coaxial with the lead wire 4. T The temperature of the alloy layer in heat sink plate 3; The diameter of the area enclosed by the heat sink plate, the three pairs of leads, and the four leads is [missing information]. D The diameter of lead 4 is d Then the shortest length of heat sink plate 3 for: when 80k > T > 4.5k hour:

[0037] when 4.5k ≥ T > 1.5k ,and ≥ hour:

[0038] when 4.5k ≥ T > 1.5k ,and < hour:

[0039] S3. Apply low-temperature adhesive to the mounting surfaces of the heat sink plate 3 and the fixed base 1, and install the heat sink plate 3, the fixed base 1 and the heat sink stud 3. S4. After applying low-temperature adhesive to the bottom of the sensor package 6, insert it into the positioning hole 12 so that it fits against the surface to be measured, and press the sensor package 6 with the clamping stud 112. S5. Install the shielding cover 2 and lead out the leads of the sensor package 6, so that they pass through the heat sink plate 3, and after winding around the heat sink stud 3, connect to the signal acquisition device to collect temperature parameters.

[0040] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0041] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A low-temperature temperature sensor mounting assembly, characterized in that, The device includes a fixed base (1) fixed on the surface of the temperature to be measured. The fixed base (1) has a positioning hole (12) that passes through the fixed base (1). The sensor package (6) passes through the positioning hole (12) and contacts the surface of the temperature to be measured. The fixed base (1) is provided with a clamping component (11) that applies a clamping force to the sensor package (6) in the direction perpendicular to the surface of the temperature to be measured. The shield (2) is placed on the surface of the fixed base (1) and forms a radiation shielding space with the fixed base (1). The lead wire (4) of the sensor package (6) passes through the shield (2). One end outside the shield (2) is heat-sinked by the heat sink plate (3), and the other end outside the shield (2) is heat-sinked by the heat sink stud (5) and then connected to the signal acquisition device.

2. The low-temperature temperature sensor mounting assembly according to claim 1, characterized in that, The clamping assembly (11) includes a rotating arm (111) that rotates with the fixed base (1). The rotation axis of the rotating arm (111) and the fixed base (1) is arranged vertically to the surface to be measured. A clamping stud (112) is installed on the rotating arm (111) along the direction parallel to the rotation axis. When the clamping stud (112) moves with the rotating arm (111) to a position corresponding to the vertical position of the sensor package (6), the clamping nut (112) and the rotating arm (111) are threaded together and then raised and lowered to apply a clamping force to the sensor package (6).

3. The low-temperature temperature sensor mounting assembly according to claim 1, characterized in that, The lead wire (4) is a four-wire lead wire, and the shield (2) has a corresponding lead wire hole for the lead wire (4) to pass through.

4. The low-temperature temperature sensor mounting assembly according to claim 1, characterized in that, The shield (2) includes a cover body placed on the fixed base (1) and a cover body at one end away from the fixed base (1). The cover body of the shield (2) has a cubic structure, and the cover body of the shield (2) has a V-shaped cover plate with an opening facing the sensor package (6). The angle of the V-shaped cover plate is 80° to 84°.

5. A low-temperature temperature sensor mounting assembly according to claim 1, characterized in that, The material of the fixed base (1) is the same as that of the surface to be measured; Alternatively, the thermal shrinkage rate between the fixed base (1) and the surface to be measured is less than 2 times.

6. A low-temperature temperature sensor mounting assembly according to claim 1, characterized in that, The heat sink plate (3) is attached to the fixed base (1). The temperature of the fixed surface of the heat sink plate (3) is the same as the temperature of the surface to be measured. When the lead wire (4) passes through the heat sink plate (3), the lead wire (4) is wrapped by the metal of the heat sink plate (3) to cool down.

7. The installation method of a low-temperature temperature sensor mounting assembly according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Determine the thickness of the shielding cover (2) according to the required shielding effectiveness, and manufacture the shielding cover (2). S2. Calculate the shortest length of the heat sink plate (3) and make the corresponding heat sink plate (3) for the lead wire (4) to pass through; S3. Apply low-temperature adhesive to the mounting surfaces of the heat sink plate (3) and the fixing base (1), and install the heat sink plate (3), the fixing base (1) and the heat sink stud (3). S4. After applying low-temperature adhesive to the bottom of the sensor package (6), place it into the positioning hole (11) so that it fits against the surface to be measured, and press the sensor package (6) with the clamping stud (112). S5. Install the shield (2) and lead out the lead wire of the sensor package (6), pass it through the heat sink plate (3), and connect it to the signal acquisition device after winding around the heat sink stud (3) to collect temperature parameters.

8. The installation method of the low-temperature temperature sensor mounting assembly according to claim 7, characterized in that, When the lead wire (4) passes through the heat sink plate (3), the alloy layer of the heat sink plate (3) forms a wrapping area coaxial with the lead wire (4). T The alloy layer temperature of the heat sink plate (3); the diameter of the area of ​​the heat sink plate (3) covering the lead wire (4) is D The diameter of lead wire (4) is d Then the shortest length of the heat sink plate (3) for: when 80k > T > 4.5k hour: when 4.5k ≥ T > 1.5k ,and ≥ hour: when 4.5k ≥ T > 1.5k ,and < hour: 。 9. The installation method of a low-temperature temperature sensor mounting assembly according to claim 7, characterized in that, The shielding effectiveness of the shielding cover (2) is : in, t The thickness of the shielding cover (2); f The frequency of the electromagnetic waves outside the shielding cover; The magnetic permeability of the shielding cover; denoted as the conductivity of the shielding cover.

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