Exhaust gas temperature sensor and assembly method

Abstract

This invention relates to the field of sensing elements, and in particular to an exhaust temperature sensor and its assembly method. The exhaust temperature sensor includes: a cover; a first sleeve, one end of which is fastened and fixedly connected to the cover; a temperature-sensing element disposed within the first sleeve; a mineral-insulated cable connected to the temperature-sensing element, with at least a portion of the mineral-insulated cable extending into the first sleeve; a sheath, which is crimped to the end of the mineral-insulated cable away from the sleeve; a first fixing module connected to the sheath; and a wire, one end of which is inserted into the sheath and connected to the mineral-insulated cable via a second fixing module. This invention offers advantages such as resistance to high temperatures up to 1000℃, protection of the temperature-sensing element, maintenance or guarantee of signal stability, excellent thermal conductivity, and reliable connection.

Description

Technical Field

[0001] This invention relates to the field of sensing elements, and in particular to an exhaust temperature sensor and its assembly method. Background Technology

[0002] An EGTS (Exhaust Gas Temperature Sensor) is a thermocouple or thermistor type sensor installed in the engine exhaust system to measure exhaust temperature in real time and convert the temperature signal into a voltage / resistance signal to feed back to the engine control unit (ECU).

[0003] Currently, conventional EGTS temperature sensor probes with chip-type temperature sensing have clear performance and structural limitations in application scenarios: the upper limit of the operating temperature of the products they are compatible with is 900℃, which cannot meet the application requirements of gas engines and gasoline engines where the upper limit temperature can reach 1000℃ or the 1000℃ temperature required in industrial applications. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problems in the prior art, thereby providing an exhaust temperature sensor and an assembly method.

[0005] In a first aspect, an exhaust temperature sensor is provided, comprising:

[0006] Cover;

[0007] The first sleeve is fastened and fixedly connected to the cover at one end;

[0008] A temperature sensing element is disposed inside the first sleeve;

[0009] A mineral-insulated cable is connected to the temperature sensing element, and at least a portion of the mineral-insulated cable extends into the first sleeve.

[0010] The sheath is crimped to the end of the mineral-insulated cable away from the sleeve.

[0011] The first fixing module is connected to the sheath;

[0012] One end of the conductor is inserted into the sheath and connected to the mineral-insulated cable via a second fixing module.

[0013] In one embodiment of the present invention, the first fixing module includes a nut fitted over the sheath and a connecting flange that mates with the nut.

[0014] In one embodiment of the present invention, the second fixing module includes a riveting member, an insulating post, and a sealing post disposed within the sheath; the end of the mineral-insulated cable away from the first sleeve and the end of the conductor near the mineral-insulated cable are both fastened to the riveting member; the end of the conductor away from the mineral-insulated cable passes sequentially through the insulating post and the sealing post; the end of the mineral-insulated cable near the insulating post is filled with sealant; wherein, the riveting member is inside the insulating post; the end of the mineral-insulated cable near the conductor abuts against the insulating post; one end of the sealing post is pressed against the insulating post, and the other end is fastened by the sheath.

[0015] In one embodiment of the present invention, the space between the temperature sensing element and the sleeve is filled with powder; the powder is magnesium oxide powder or aluminum oxide powder.

[0016] In one embodiment of the present invention, the cover includes a large-diameter section and a small-diameter section, and the end of the sleeve adjacent to the cover is fastened to the small-diameter section and abuts against the surface of the large-diameter section.

[0017] In one embodiment of the present invention, the mineral-insulated cable includes a cable sheath and a lead wire disposed within the cable sheath and connected to the temperature sensing element; at least a portion of the cable sheath extends into the first sleeve, and at least a portion extends into the sheath.

[0018] In one embodiment of the invention, a connector is further included that connects the conductor and the mineral-insulated cable.

[0019] In one embodiment of the present invention, a second sleeve is fitted over the portion of the conductor exposed from the sheath.

[0020] Secondly, an assembly method is provided for assembling the aforementioned exhaust temperature sensor, comprising the following steps:

[0021] Install the second fixing module inside the protective sleeve;

[0022] The sheath and mineral-insulated cable are fastened together and fixed with laser welding;

[0023] One end of the mineral-insulated cable is fixed to the temperature sensing element, and the other end passes through the sheath and the second fixing module and is connected to one end of the conductor.

[0024] The first sleeve is wrapped around the temperature sensing element and part of the mineral-insulated cable;

[0025] The cover and the first sleeve are laser welded to the end adjacent to the cover;

[0026] The first fixing module is fixedly fitted onto the protective sleeve.

[0027] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0028] The exhaust temperature sensor described in this invention has excellent performance in withstanding high temperatures of 1000℃, which can effectively protect the internal temperature sensing element from direct corrosion and damage by high-temperature flue gas, and ensure continuous and stable output of the sensing signal under complex working conditions of high temperature and vibration. At the same time, the sensor also has excellent thermal conductivity, which can quickly and accurately capture changes in exhaust temperature and realize signal transmission. Furthermore, the connection structure design has been optimized, which greatly improves the reliability of the connection with pipelines and control systems, and is suitable for the long-term stable operation requirements of various high-temperature application scenarios such as industrial power and internal combustion engine exhaust systems. Attached Figure Description

[0029] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0030] Figure 1 This is a front view of the exhaust temperature sensor in this invention;

[0031] Figure 2 This is a side view of the exhaust temperature sensor in this invention;

[0032] Figure 3 yes Figure 2 Sectional view at point AA;

[0033] Figure 4 yes Figure 3 Enlarged view of point B in the middle;

[0034] Figure 5 This is a schematic diagram of the structure of the cover in this invention;

[0035] Figure 6 This is a front view of the sleeve in this invention;

[0036] Figure 7 This is the front view of the sheath in this invention.

[0037] Explanation of reference numerals on the accompanying drawings:

[0038] 101. Cover; 1011. Recessed portion; 1012. Large diameter section; 1013. Small diameter section;

[0039] 102. First sleeve; 1021. Coarse sleeve; 1022. Fine sleeve;

[0040] 103. Mineral-insulated cable; 1031. Cable sheath; 1032. Lead wire;

[0041] 104. Sheath; 105. Connecting flange; 106. Nut; 107. Second sleeve; 108. Connector; 109. Rivet; 110. Insulating post; 111. Sealing post; 112. Wire;

[0042] 20. Temperature sensing element. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0044] In traditional exhaust temperature sensor applications, the limited upper limit of the sensor's operating temperature constitutes a significant technical obstacle. Furthermore, this problem directly restricts the long-term stability of the sensor in high-temperature exhaust environments, making it difficult to maintain the reliability of the temperature detection signal and affecting the engine control unit's precise control of exhaust temperature.

[0045] If the aforementioned issues are not addressed, the risk of signal distortion from the exhaust temperature sensor under high-temperature conditions will persist, potentially leading to misjudgments by the engine control unit, resulting in decreased combustion efficiency or excessive emissions. Therefore, the sensor's environmental adaptability poses a systemic threat to the engine performance monitoring system, necessitating technological breakthroughs through structural innovation.

[0046] In this regard, combined with Figures 1 to 4 , Figure 6 and Figure 7 This embodiment proposes the following technical solution:

[0047] An exhaust temperature sensor, comprising:

[0048] Cover 101;

[0049] The first sleeve 102, with one end adjacent to the cover 101, abuts against the cover 101 and is fixedly connected;

[0050] The temperature sensing element 20 is disposed inside the first sleeve 102;

[0051] Mineral insulated cable 103 is connected to temperature sensing element 20 and at least a portion of mineral insulated cable 103 extends into the sleeve.

[0052] The sheath 104 is crimped to the end of the mineral-insulated cable 103 away from the sheath.

[0053] The first fixing module is connected to the sheath 104;

[0054] One end of the conductor 112 is inserted into the sheath 104 and connected to the mineral-insulated cable 103 via the second fixing module.

[0055] This embodiment provides an exhaust temperature sensor, which aims to solve the problems of weak wear and pollution resistance caused by lack of physical protection in the structure and insufficient vibration resistance caused by fragile connection structure.

[0056] In this design, one end of the first sleeve 102 is inserted into the cover 101, and the sleeve and cover 101 are fixedly connected by laser welding. Figure 6 As shown, in this embodiment, the first sleeve 102 includes a coarse sleeve 1021 and a fine sleeve 1022. The coarse sleeve 1021 is lightly pressed together with the fine sleeve 1022 and then welded, without the need for stamping.

[0057] The temperature sensing element 20 is fixed inside the first sleeve 102 to sense changes in exhaust temperature in real time.

[0058] One end of the mineral-insulated cable 103 is electrically connected to the temperature sensing element 20, and the other end extends at least partially into the sleeve to achieve sealed protection of the signal transmission path.

[0059] The sheath 104 is connected to the end of the mineral-insulated cable 103 away from the sleeve by a crimping method, providing positioning and fixation.

[0060] One end of the conductor 112 is inserted into the sheath 104 and connected to the end of the mineral-insulated cable 103 through the second fixing module to ensure the stability of electrical contact.

[0061] This solution effectively blocks the intrusion of external contaminants through the gap fit between the sheath 104 and the mineral-insulated cable 103, while the second fixing module strengthens the structural strength of the connection point, thereby maintaining the reliability of signal transmission in a vibration environment.

[0062] like Figure 3 As shown, this embodiment further proposes a first fixing module including a nut 106 fitted outside the sheath 104 and a connecting flange 105 fitted outside the sheath 104 and cooperating with the nut 106.

[0063] Nut 106 refers to a standard fastener that can be implemented in the form of a hexagonal nut, round nut, or flange nut. Its purpose is to provide a stable axial clamping force through thread tightening, so as to avoid loosening of the connection due to vibration.

[0064] The connecting flange 105 can be understood as a ring-shaped connecting component, the purpose of which is to provide uniform radial support for the sleeve 104 and ensure reliable engagement with the nut 106, thereby enhancing the vibration resistance of the overall structure.

[0065] It should be noted that the nut 106 on the exhaust temperature sensor is in a loose state and can move axially. The nut 106 is fitted between the connector 108 and the connecting flange 105, and its function is to fix the exhaust temperature sensor in the mounting hole (not shown in the figure) on the client side. After installation, the nut 106 will press the connecting flange 105 together, which serves to seal and limit the movement.

[0066] Through the above solution, this embodiment effectively solves the problem of loose connection points under vibration environment, ensures the stability of signal transmission, reduces the risk of component detachment, and meets the long-term reliability requirements of engine exhaust system under high vibration conditions.

[0067] Combination Figure 3 and Figure 4 This embodiment further proposes a second fixing module including a riveting member 109, an insulating post 110, and a sealing post 111 disposed within the sheath 104; the end of the mineral-insulated cable 103 away from the sheath and the end of the conductor 112 near the mineral-insulated cable 103 are both fastened to the riveting member 109; the end of the conductor 112 away from the mineral-insulated cable 103 passes through the insulating post 110 and the sealing post 111 in sequence; the end of the mineral-insulated cable 103 near the insulating post 110 is filled with sealant; wherein, the riveting member 109 is inside the insulating post 110; the end of the mineral-insulated cable 103 near the conductor 112 abuts against the insulating post 110; one end of the sealing post 111 is pressed against the insulating post 110, and the other end is fastened by the sheath 104.

[0068] Among them, the riveting component 109 refers to the metal component that realizes electrical connection and mechanical fixation, and its purpose is to ensure the electrical contact stability between the mineral insulated cable 103 and the conductor 112 under dynamic load.

[0069] Insulating post 110 refers to a component that provides electrical isolation, with the purpose of blocking the current path between conductor 112 and sheath 104, as well as short circuits between mineral insulated cable 103 and conductor 112.

[0070] The sealing post 111 is an elastic component that achieves environmental isolation. It can be made of fluororubber through molding and aims to prevent external contaminants from entering the connection area of ​​the wire 112. The other end of the sealing post 111 is compressed and limited by the sheath 104, which also serves to seal it.

[0071] Sealants are chemical media used to fill gaps and bond materials together. They can be made from high-temperature resistant organic materials such as epoxy resin, silicone, or polyurethane. Their purpose is to block contaminants and moisture, and solve problems such as reduced insulation or unstable signals caused by contaminants and moisture.

[0072] The arrangement of conductor 112 passing through insulating post 110 and sealing post 111 in sequence refers to the formation of a multi-level stress buffer structure, the purpose of which is to attenuate vibration energy step by step to protect critical connection points.

[0073] Specifically, the solution in this embodiment avoids relative displacement between the riveting member 109 and the insulating post 110 in a vibrating environment. The sequential arrangement of the conductor 112 passing through the insulating post 110 and the sealing post 111 allows the vibration stress to be distributed and absorbed step by step by the multi-layer structure. The conductor 112 is mainly fixed within the sheath 104 by the riveting member 109, forming a redundant fixing mechanism, thereby ensuring the continuous reliability of the electrical path.

[0074] As a specific implementation method, the solution of this embodiment is implemented as follows: The riveting component 109 adopts a stamped structure with U-shaped buckles at both ends, and its open end is fastened to the core of the mineral-insulated cable 103 and the conductor 112. The riveting component 109 and the mineral-insulated cable 103 need to be further laser-stitched to ensure the connection strength. The insulating post 110 is a double-hole cylinder made of alumina ceramic. The sealing post 111 is an annular double-hole seal made of fluororubber, and its inner hole is interference-fitted with the conductor 112. The conductor 112 passes through the central hole of the insulating post 110 and the sealing hole of the sealing post 111 in sequence, and is finally limited and fixed by the end of the sheath 104.

[0075] The specific installation sequence is as follows: the sealing post 111 is put on the conductor 112 and then the insulating post 110 is put on it. Then the terminal of the conductor 112 is welded to the mineral insulated cable 103. After the welding is completed, the insulating post 110 and the sealing post 111 are pushed into the sheath 104 at the end of the conductor 112.

[0076] This embodiment further proposes filling the space between the temperature sensing element 20 and the sleeve with powder (not shown in the figure); wherein the powder is magnesium oxide powder or aluminum oxide powder.

[0077] Among them, the filling powder can be understood as a material used to fill the gap between the temperature sensing element 20 and the sleeve, and its purpose is to conduct heat and dampen vibration; the magnesium oxide powder as the filling material can be understood as a high thermal conductivity insulating medium, which can be achieved by using industrial-grade magnesium oxide powder or surface-modified magnesium oxide powder, and its purpose is to maintain insulation performance and thermal conductivity efficiency under ultra-high temperature environment, effectively ensuring rapid temperature conduction and stable signal transmission.

[0078] Specifically, the solution in this embodiment fills the gap between the temperature sensing element 20 and the sleeve with powder to form a continuous and uniform support layer. This support layer can effectively absorb the vibration energy generated by the engine exhaust system and disperse thermal stress, thereby preventing the temperature sensing element 20 from sliding relative to each other during operation. The powder maintains its insulation performance and thermal conductivity in high-temperature and ultra-high-temperature environments, effectively ensuring rapid temperature conduction and stable signal transmission. At the same time, the high thermal conductivity of magnesium oxide powder accelerates the transfer path of exhaust heat to the temperature sensing element 20, and its insulation performance blocks electrical interference, jointly ensuring the accuracy and reliability of temperature signal acquisition.

[0079] Combination Figure 5 The cover 101 includes an integrally formed large-diameter section 1012 and a small-diameter section 1013. The end of the sleeve adjacent to the cover 101 is fastened to the small-diameter section 1013 and abuts against the surface of the large-diameter section 1012. The top outer part of the large-diameter section 1012 is recessed towards the small-diameter section 1013, forming a recessed portion 1011.

[0080] This embodiment further proposes that the mineral insulated cable 103 includes a cable sheath 1031 and a lead wire 1032 disposed in the cable sheath 1031 and connected to the temperature sensing element 20; at least a portion of the cable sheath 1031 extends into the sleeve and at least a portion extends into the sheath 104.

[0081] The cable sheath 1031 can be made of metal or ceramic materials to protect the lead wire 1032 from external mechanical stress and environmental corrosion. Its purpose is to ensure the signal transmission stability of the lead wire 1032 under high temperature conditions. The cable sheath 1031 is designed to extend into the bushing at least part of it. Specifically, the cable sheath 1031 can extend into the inside of the bushing to form a transition connection. Its purpose is to enhance the sealing and mechanical stability of the interface between the mineral insulated cable 103 and the bushing, and to prevent gas or pollutants from entering the internal cavity.

[0082] This embodiment further proposes that the exhaust temperature sensor also includes a connector 108 connected by a wire 112 and a mineral-insulated cable 103.

[0083] The connector 108 can be understood as a standardized detachable electrical connection module, which can be implemented using a rectangular connector or an industrial-grade quick-connect connector. Its purpose is to provide the ability to quickly disconnect and connect, so as to facilitate the independent replacement of local components during maintenance operations, thereby avoiding the disassembly of the overall structure.

[0084] Specifically, the solution in this embodiment forms a modular signal transmission path by connecting the connector 108 with the wire 112 and the mineral-insulated cable 103.

[0085] This embodiment further proposes that the portion of the conductor 112 exposed from the sheath 104 is fitted with a second sleeve 107.

[0086] This embodiment further proposes that the temperature sensing element 20 is an NTC thermistor chip or a PT chip.

[0087] Among them, NTC thermistor chip refers to a semiconductor temperature sensitive element with negative temperature coefficient characteristics. It can be implemented by using ceramic chips made of metal oxides such as manganese, cobalt, and nickel sintered together, or thin film chips made of semiconductor materials. Its purpose is to ensure that a regular resistance value response is generated when the temperature changes, so as to directly adapt to the signal input requirements of the control module.

[0088] PT chips refer to platinum resistance temperature sensor chips, such as the PT200 type. Their purpose is to provide stable temperature-resistance linear response characteristics under high temperature environments, avoiding signal drift problems caused by material nonlinearity or aging effects.

[0089] Specifically, the solution in this embodiment limits the temperature sensing element 20 to an NTC thermistor chip, and utilizes the physical characteristic that its resistance value decreases regularly as the temperature rises to generate a resistance signal corresponding to the temperature in real time during the change of exhaust temperature. This resistance signal can be directly transmitted to the control module without additional conversion, thereby forming a matching relationship with the input interface design of the control module, effectively ensuring the accurate transmission of temperature data and the stable operation of the system.

[0090] This embodiment also discloses an assembly method for assembling the aforementioned exhaust temperature sensor, including the following steps:

[0091] The second fixing module is installed inside the sheath 104;

[0092] The sheath 104 and the mineral-insulated cable 103 are fastened together and fixed by laser welding;

[0093] One end of the mineral-insulated cable 103 is fixed to the temperature sensing element 20, and the other end passes through the sheath 104 and the second fixing module and is connected to one end of the conductor 112.

[0094] The first sleeve 102 is wrapped around the temperature sensing element 20 and a portion of the mineral-insulated cable 103;

[0095] The cover 101 and the sleeve are fastened together at the end adjacent to the cover 101 and fixed by laser welding; before this process, filling powder is filled between the temperature sensing element 20 and the first sleeve 102.

[0096] The first fixing module is fixedly sleeved onto the sheath 104.

[0097] Specifically, the pre-installation of the second fixing module ensures a modular layout of the electrical connection structure, providing a foundation for the subsequent reinforced connection between the mineral-insulated cable 103 and the conductor 112. The fixing of the first fixing module and the sheath 104 forms a stable connection. The path design of the mineral-insulated cable 103 is based on the internal structure of the second fixing module for threading, effectively preventing relative displacement caused by vibration. The first sleeve 102's wrapping of the temperature-sensing element 20 and the filling of magnesium oxide powder optimize the heat conduction path.

[0098] The above technical solutions significantly improve the sensor's environmental adaptability under complex working conditions.

[0099] It should be noted that mineral-insulated cables used in vehicles typically come in diameters of 3mm and 6mm. 6mm mineral-insulated cables are used in commercial vehicles, while 3mm mineral-insulated cables are used in passenger vehicles. The mineral-insulated cable provided in this embodiment is a 3mm design with a reinforced sheath, making it suitable for both commercial and passenger vehicle applications. This solution is more economical than directly using a 6mm mineral-insulated cable.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An exhaust temperature sensor, characterized in that, include: Cover (101); The first sleeve (102) is fastened and fixedly connected to the cover (101) at one end; A temperature sensing element (20) is disposed inside the first sleeve (102); A mineral-insulated cable (103) is connected to the temperature sensing element (20), and at least a portion of the mineral-insulated cable (103) extends into the first sleeve (102); The sheath (104) and the end of the mineral-insulated cable (103) away from the sleeve are crimped together; The first fixing module is connected to the sheath (104); One end of the conductor (112) is inserted into the sheath (104) and connected to the mineral-insulated cable (103) via the second fixing module.

2. The exhaust temperature sensor according to claim 1, characterized in that, The first fixing module includes a nut (106) fitted over the sheath (104) and a connecting flange (105) that mates with the nut (106).

3. The exhaust temperature sensor according to claim 1, characterized in that, The second fixing module includes a riveting component (109), an insulating post (110), and a sealing post (111) disposed within the sheath (104); the end of the mineral-insulated cable (103) away from the first sleeve (102) and the end of the conductor (112) near the mineral-insulated cable (103) are both fastened to the riveting component (109); the end of the conductor (112) away from the mineral-insulated cable (103) passes sequentially through the insulating post (110) and the sealing post (111); the end of the mineral-insulated cable (103) near the insulating post (110) is filled with sealant; wherein, the riveting component (109) is inside the insulating post (110); the end of the mineral-insulated cable (103) near the conductor (112) abuts against the insulating post (110); one end of the sealing post (111) is pressed on the insulating post (110), and the other end is fastened by the sheath (104).

4. The exhaust temperature sensor according to claim 1, characterized in that, The temperature sensing element (20) and the sleeve are filled with powder; the powder is magnesium oxide powder or aluminum oxide powder.

5. The exhaust temperature sensor according to claim 1, characterized in that, The cover (101) includes a large-diameter section (1012) and a small-diameter section (1013). The end of the sleeve adjacent to the cover (101) is fastened to the small-diameter section (1013) and abuts against the surface of the large-diameter section (1012).

6. The exhaust temperature sensor according to claim 1, characterized in that, The mineral-insulated cable (103) includes a cable sheath (1031) and a lead wire (1032) disposed inside the cable sheath (1031) and connected to the temperature sensing element (20); at least a portion of the cable sheath (1031) extends into the first sleeve (102) and at least a portion extends into the sheath (104).

7. The exhaust temperature sensor according to claim 1, characterized in that, It also includes a connector (108) that connects the conductor (112) and the mineral-insulated cable (103).

8. The exhaust temperature sensor according to claim 1, characterized in that, The portion of the conductor (112) exposed from the sheath (104) is fitted with a second sleeve (107).

9. An assembly method, characterized in that, Assembling the exhaust temperature sensor as described in any one of claims 1-8 includes the following steps: The second fixing module is installed inside the sheath (104); The sheath (104) and the mineral-insulated cable (103) are fastened together and fixed by laser welding; One end of the mineral-insulated cable (103) is fixed to the temperature sensing element (20), and the other end passes through the sheath (104) and the second fixing module and is connected to one end of the conductor (112); The first sleeve (102) is wrapped around the temperature sensing element (20) and a portion of the mineral-insulated cable (103). The cover (101) and the first sleeve (102) are laser welded to the end adjacent to the cover (101); The first fixing module is fixedly sleeved onto the sheath (104).

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