A temperature sensor for measuring total temperature of a gas stream

Abstract

The utility model provides a kind of temperature sensor for measuring total temperature of airflow, comprising: support, the axial direction of support is equipped with the first passage of two ends communication;Protective tube, protective tube is worn in support and is connected with support, to make protective tube overhanging first passage;Stagnation cover, the axial direction of stagnation cover is equipped with the second passage of one end open, stagnation cover is equipped with air inlet and air outlet with the second passage in radial direction communication, stagnation cover is set on protective tube and support and is connected with support, to make protective tube overhanging in second passage;Temperature sensing element, temperature sensing element is installed in protective tube and located at the air inlet of second passage, and the pin of temperature sensing element is connected with signal line. The temperature sensor for measuring total temperature of airflow is simple in structure, strong in shock resistance, fast in detection response speed.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a temperature sensor for measuring the total temperature of airflow. Background Technology

[0002] The total airflow temperature includes both static and dynamic airflow temperatures. The engine intake total airflow temperature sensor rapidly reduces the airflow velocity through the dual blocking effect of the stagnation cover and protective tube. During this process, the kinetic energy of the gas is converted into heat energy. The temperature sensing element of the total airflow temperature sensor can sense the total airflow temperature signal after the airflow is blocked and convert the total airflow temperature signal into a temperature sensing element signal, which is then output to the engine control system via a cable.

[0003] The main function of the total temperature sensor's protective tube is to isolate the external airflow from direct contact with the temperature sensing element, thereby extending the element's lifespan. However, the protective tube also increases the thermal resistance between the airflow and the sensing element, reducing the sensor's thermal response speed. In existing total temperature sensors, one end of the protective tube is fixed to a mounting bracket, while the other end is freely suspended. Under airflow, this structure generates a large bending moment in the connection area and is prone to stress concentration. Therefore, to reduce the risk of tube breakage, a large-diameter tube is required. However, increasing the tube diameter also increases the thermal resistance. To address this issue, utility model patent CN207487844 proposes using a groove in the protective tube to expose the internal temperature sensing element, reducing the sensor's thermal response time constant through direct contact between the sensing element and the airflow. However, with the sensing element directly exposed to the airflow, it is vulnerable to vibrations from the engine intake system, airflow impacts, and mechanical stress during installation. This can lead to signal wire breakage and sensing element damage during operation, significantly reducing the sensor's lifespan. Utility Model Content

[0004] The present invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, the purpose of this invention is to provide a temperature sensor for measuring the total temperature of airflow, which has a simple structure, strong shock resistance, and fast detection response speed.

[0005] To achieve the above objectives, this utility model proposes a temperature sensor for measuring the total temperature of airflow, comprising:

[0006] The support has a first channel with two connected ends in the axial direction;

[0007] A protective tube is inserted through and connected to the support, so that the protective tube extends out of the first channel;

[0008] A stagnation cover is provided with a second channel with one end open in the axial direction. The stagnation cover is provided with an air inlet and an air outlet that communicate with the second channel in the radial direction. The stagnation cover is sleeved on the protective tube and the support and connected to the support so that the protective tube is suspended in the second channel.

[0009] A temperature sensing element is installed inside the protective tube and located at the air inlet of the second channel. A signal line is connected to the pin of the temperature sensing element.

[0010] According to this utility model, a temperature sensor for measuring the total temperature of airflow is proposed. The connection and fixation between the stagnation cover and the support, and between the protective tube and the support, improves the support strength of the stagnation cover and the protective tube. The gap fit between the stagnation cover and the protective tube allows the inner wall of the stagnation cover to support the overhanging part of the protective tube when it swings, thus improving the radial support strength of the protective tube. The air inlet and outlet of the stagnation cover allow the airflow to directly contact the protective tube. Therefore, the wall thickness of the stagnation cover and the wall thickness of the protective tube can be set more flexibly, which helps to reduce thermal resistance, improve the thermal response speed of the temperature sensing element inside the protective tube, and simultaneously improve the radial support strength of the protective tube, ensuring the overall service life of the temperature sensor.

[0011] In addition, the temperature sensor for measuring the total temperature of airflow according to the above embodiments of this utility model may also have the following additional technical features:

[0012] Optionally, the stagnation cover is threaded or welded to the support.

[0013] Furthermore, the support includes a first boss extending radially, and the stagnation cover includes a second boss extending radially, the first boss and the second boss being threaded or welded together.

[0014] Optionally, the protective tube and the second channel are clearance-fitted in both the axial and radial directions.

[0015] Furthermore, the second channel includes a first channel segment and a second channel segment, the diameter of the second channel segment is smaller than the diameter of the first channel segment, the insertion end of the protective tube is located in the second channel segment, and the air inlet and the air outlet are located in the first channel segment.

[0016] Optionally, the protective tube is a capillary metal tube.

[0017] Optionally, the air inlet and the air outlet are arranged opposite to each other.

[0018] Optionally, the protective tube is filled with a heat-conducting medium. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a temperature sensor for measuring the total temperature of airflow according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the stagnation cover according to an embodiment of the present utility model;

[0021] Figure 3 This is a structural schematic diagram of the assembly state of the protective tube and the temperature sensing element according to an embodiment of the present utility model;

[0022] Figure 4 This is a schematic diagram of the support structure according to an embodiment of the present utility model;

[0023] Explanation of reference numerals in the attached figures:

[0024] Support 1, first channel 11, first boss 12, slot 13, protective tube 2, stagnation cover 3, second channel 31, first section channel 311, second section channel 312, air inlet 32, air outlet 33, second boss 35, temperature sensing element 4, signal line 41, heat-conducting medium 5. Detailed Implementation

[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0026] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0027] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0028] The following is for reference. Figures 1-4 The implementation of the temperature sensor for measuring the total temperature of airflow proposed in the embodiments of this utility model will be described in detail.

[0029] A temperature sensor for measuring the total temperature of an airflow according to an embodiment of the present invention includes:

[0030] Support 1, wherein the support 1 is provided with a first channel 11 with both ends communicating in the axial direction;

[0031] A protective tube 2 is inserted through and connected to the support 1, so that the protective tube 2 extends out of the first channel 11;

[0032] The stagnation cover 3 has a second channel 31 with one end open in the axial direction. The stagnation cover 3 has an air inlet 32 ​​and an air outlet 33 that communicate with the second channel 31 in the radial direction. The stagnation cover 3 is sleeved on the protective tube 2 and the support 1 and connected to the support 1 so that the protective tube 2 is suspended in the second channel 31.

[0033] Temperature sensing element 4 is installed inside the protective tube 2 and located at the air inlet 32 ​​of the second channel 31. Signal line 41 is connected to the pin of the temperature sensing element 4.

[0034] In other words, the temperature sensing element 4 is installed inside the protective tube 2, and the signal line 41 of the temperature sensing element 4 extends from the port of the protective tube 2. The protective tube 2 is used to protect the temperature sensing element 4 and conduct heat to the temperature sensing element 4, preventing the temperature sensing element 4 from directly contacting the external airflow. One end of the protective tube 2 is inserted into the first channel 11 of the support 1 and connected to the support 1 to form a sub-assembly. The second channel 31 of the stagnation cover 3 is fitted into the sub-assembly and connected to the support 1, so that the protective tube 2 is suspended in the second channel 31, forming a gap fit between the suspended part of the protective tube 2 and the inner wall of the second channel 31. When the airflow enters from the air inlet 32 ​​of the stagnation cover 3 and acts on the protective tube 2, the protective tube 2 can be blocked. The shroud 3 confines the second channel 31 to prevent large-scale swaying, thus avoiding mechanical damage to the connection between the protective tube 2 and the support 1 caused by airflow or vibration. The suspended protective tube 2 can adapt to thermal expansion and contraction without bearing additional thermal stress. Since the shroud 3 is provided with an air inlet 32 ​​and an air outlet 33, the airflow can directly contact the protective tube 2. The wall thickness of the shroud 3 can be set to be thicker, which is beneficial to improve the support strength of the shroud 3. The wall thickness of the protective tube 2 can be set to be thinner under the support of the shroud 3 and the support 1, which is conducive to improving the thermal response speed of the temperature sensing element 4, while ensuring the service life of the protective tube 2 and the temperature sensing element 4.

[0035] The protective tube 2 and the support 1 can be connected by welding or tight fitting at the joint. The stagnation cover 3 and the support 1 can be connected by welding, thread, or snap-fit. The second channel 31 can be a regular cylindrical channel or a cylindrical channel with a variable diameter. The stagnation cover 3, the protective tube 2, and the support 1 can be made of high-temperature resistant metal materials. The temperature sensing element 4 can be a resistance temperature sensing element 4. Both the insertion end of the support 1 and the insertion end of the protective tube 2 are provided with bevels to ensure smooth insertion. The temperature sensing element 4 and the protective tube 2 can be in direct contact for heat conduction or can be conducted through filler.

[0036] Therefore, the connection and fixation between the stagnation cover 3 and the support 1, and between the protective tube 2 and the support 1, improves the support strength of the stagnation cover 3 and the protective tube 2. The clearance fit between the stagnation cover 3 and the protective tube 2 allows the inner wall of the stagnation cover 3 to support the overhanging part of the protective tube 2 when it swings, thus improving the radial support strength of the protective tube 2. The air inlet 32 ​​and air outlet 33 of the stagnation cover 3 allow the airflow to directly contact the protective tube 2. In this way, the wall thickness of the stagnation cover 3 and the wall thickness of the protective tube 2 can be set more flexibly, which helps to reduce thermal resistance, improve the thermal response speed of the temperature sensing element 4 inside the protective tube 2, and improve the radial support strength of the protective tube 2, ensuring the service life of the overall temperature sensor. In other words, the structure of this temperature sensor has no stress concentration, the fixing point will not be subjected to excessive torque, and the stress state is good. Therefore, it is permissible to use a thin-walled tube for the protective tube, which can reduce thermal resistance and improve thermal response speed. The existing cantilevered protective tube structure lacks radial support. Using thin-walled protective tubes makes them prone to breakage, while using thick-walled protective tubes inevitably leads to a significant increase in thermal resistance and a slower response speed.

[0037] Optionally, the stagnation cover 3 and the support 1 are threaded or welded. Understandably, a threaded connection facilitates the assembly and disassembly of the stagnation cover 3 and the support 1, thereby promoting product interchangeability and modular design. Welding ensures the reliability of the connection between the stagnation cover 3 and the support 1, as well as the assembly efficiency, eliminating the need for complex connection structures and aiding cost control. Specifically, the stagnation cover 3 and the support 1 can be threaded at the joint or welded at the edge of the joint. The joint can be tight-fitting to improve the support of the stagnation cover 3. The support 1 can be provided with a slot 13 for a wrench to be inserted, facilitating the stress on the threaded connection.

[0038] Furthermore, the support 1 includes a first boss 12 extending radially, and the retaining cover 3 includes a second boss 35 extending radially. The first boss 12 and the second boss 35 are threaded or welded together. Understandably, the arrangement of the first boss 12 and the second boss 35 provides a larger connection area between the support 1 and the retaining cover 3, thereby improving the reliability of the connection between them. The retaining cover 3 and the support 1 can generally be T-shaped.

[0039] Optionally, the protective tube 2 and the second channel 31 are clearance-fitted in both the axial and radial directions. Understandably, by configuring the protective tube 2 and the second channel 31 with clearance fits in both the axial and radial directions, axial and radial clearance space can be provided for the protective tube 2 during thermal expansion, thereby ensuring that the protective tube 2 does not bear additional thermal stress and improving its service life.

[0040] Furthermore, the second channel 31 includes a first channel 311 and a second channel 312. The diameter of the second channel 312 is smaller than the diameter of the first channel 311. The insertion end of the protective tube 2 is located in the second channel 312, while the air inlet 32 ​​and the air outlet 33 are located in the first channel 311. Understandably, because the insertion end of the protective tube 2 is located within the smaller diameter second channel 312, the second channel 312 can radially restrict and support the insertion end of the protective tube 2, thus ensuring that the protective tube 2 does not sway significantly. Meanwhile, the first channel 311 provides ample space for airflow to enter from the air inlet 32 ​​and exit from the air outlet 33, ensuring smooth airflow and consequently, accurate temperature measurement.

[0041] Optionally, the protective tube 2 is a capillary metal tube. Understandably, using a standard capillary metal tube as the protective tube 2 is beneficial for cost control. The capillary metal tube can be made of stainless steel, and its outer diameter can be 3mm.

[0042] Optionally, the air inlet 32 ​​and the air outlet 33 are arranged opposite to each other. Understandably, arranging the air inlet 32 ​​and the air outlet 33 opposite to each other improves the smoothness of airflow, thereby ensuring the accuracy of temperature detection. There can be one air inlet 32 ​​and two air outlets 33.

[0043] Optionally, the protective tube 2 is filled with a thermally conductive medium 5. Understandably, the filling with the thermally conductive medium 5 allows heat from the protective tube 2 to be conducted to the temperature-sensing element 4, thereby filling the gap between the temperature-sensing element 4 and the protective tube 2 and improving the shock resistance of the temperature-sensing element 4. The thermally conductive medium 5 can be thermally conductive adhesive, and the temperature-sensing element 4 can be a platinum resistance thermometer. One signal line 41 is connected to one pin of the platinum resistance thermometer, and two signal lines 41 are connected to the other pin.

[0044] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A temperature sensor for measuring the total temperature of an airflow, characterized in that, include: The support has a first channel with two connected ends in the axial direction; A protective tube is inserted through and connected to the support, so that the protective tube extends out of the first channel; A stagnation cover is provided with a second channel with one end open in the axial direction. The stagnation cover is provided with an air inlet and an air outlet that communicate with the second channel in the radial direction. The stagnation cover is sleeved on the protective tube and the support and connected to the support so that the protective tube is suspended in the second channel. A temperature sensing element is installed inside the protective tube and located at the air inlet of the second channel. A signal line is connected to the pin of the temperature sensing element.

2. The temperature sensor for measuring the total temperature of airflow as described in claim 1, characterized in that, The stagnation cover is threaded or welded to the support.

3. The temperature sensor for measuring the total temperature of airflow as described in claim 2, characterized in that, The support includes a first boss extending radially, and the stagnation cover includes a second boss extending radially, the first boss and the second boss being threaded or welded together.

4. The temperature sensor for measuring the total temperature of airflow as described in claim 1, characterized in that, The protective tube and the second channel are clearance-fitted in both the axial and radial directions.

5. The temperature sensor for measuring the total temperature of airflow as described in claim 3, characterized in that, The second channel includes a first channel and a second channel. The diameter of the second channel is smaller than the diameter of the first channel. The insertion end of the protective tube is located in the second channel, and the air inlet and the air outlet are located in the first channel.

6. The temperature sensor for measuring the total temperature of airflow as described in claim 1, characterized in that, The protective tube is a capillary metal tube.

7. The temperature sensor for measuring the total temperature of airflow as described in claim 1, characterized in that, The air inlet and the air outlet are positioned opposite each other.

8. The temperature sensor for measuring the total temperature of airflow as described in claim 1, characterized in that, The protective tube is filled with a heat-conducting medium.

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