A temperature sensor for a marine engine

Abstract

The present invention relates to a temperature sensor for a marine engine, comprising: a metal protection outer tube, a thermal resistance element, a high-temperature resistant wire, and a high-temperature signal cable. The metal protection outer tube is formed by sequentially connecting a first-section metal tube, a variable cross-section sleeve, and a second-section metal tube. A sealed connection end is welded to the end of the second-section metal tube. The thermal resistance element is arranged at the end of the first-section metal tube. The high-temperature resistant wire extends from the first-section metal tube to the sealed connection end. One end of the high-temperature resistant wire is welded to the thermal resistance element, and the other end is welded to one end of the high-temperature signal cable, and the welding point is located inside the sealed connection end. The inside of the temperature measurement end is filled with an inorganic insulating material. The gaps between the leads of the thermal resistance element and the gaps between the high-temperature resistant wires are filled with a high-temperature inorganic adhesive. The inside of the sealed connection end is filled with a high-temperature insulating sealant. This sensor can withstand a certain margin of vibration, shock, bump, tilt and swing, etc., and has good mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature sensors, and particularly relates to a temperature sensor for a marine engine. Background Art

[0002] In order to ensure the safe operation of a ship, temperature sensors for monitoring are usually installed at key measuring points on the marine engine to detect the temperature of key points and realize real-time monitoring of the temperature of the marine engine.

[0003] A temperature sensor refers to a sensor that can sense temperature and convert it into an available output signal. A temperature sensor is the core part of a temperature measuring instrument and comes in a wide variety. It can be divided into two categories: contact type and non-contact type according to the measurement method, and into two categories: thermal resistance and thermocouple according to the characteristics of the sensor material and electronic components.

[0004] Currently, the sensors for monitoring the temperature of key points on domestic marine engines use thermocouple temperature sensors, and those on foreign marine engines use thermal resistance elements for temperature measurement. However, the measurement accuracy of thermocouple temperature sensors is relatively low, and it cannot meet the need for accurate temperature monitoring under conditions such as high temperature, strong vibration, and sudden accident impact of the engine.

[0005] Therefore, under the background of localization, how to design and manufacture a temperature sensor for a marine engine to meet the requirement of still being able to accurately monitor the temperature under conditions such as high temperature, strong vibration, and sudden accident impact of the engine has become an urgent problem to be solved currently. Summary of the Invention

[0006] In order to solve the above problems existing in the prior art, the present invention provides a temperature sensor for a marine engine. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0007] An embodiment of the present invention provides a temperature sensor for a marine engine, including: a metal protection outer tube, a thermal resistance element, a high-temperature resistant wire, and a high-temperature signal cable, wherein,

[0008] The metal protection outer tube is formed by sequentially connecting a first-section metal tube, a variable cross-section sleeve, and a second-section metal tube, and a sealed connection end is welded to the end of the second-section metal tube;

[0009] The thermal resistance element is arranged at the end of the first-section metal tube to form a temperature measurement end, and the temperature measurement end realizes pressure-bearing sealing; the small end of the variable cross-section sleeve is close to the temperature measurement end;

[0010] The high-temperature resistant wire extends from the first-section metal tube, the variable cross-section sleeve, and the second-section metal tube to the sealed connection end; one end of the high-temperature resistant wire is welded to the thermal resistance element, and the other end is welded to one end of the high-temperature signal cable, and the welding point is located inside the sealed connection end;

[0011] The high-temperature signal cable is connected to the end of the high-temperature resistant wire to form a shielded wire, and the shielded wire extends out of the sealed connection end; the metal protective outer tube, the sealed connection end, and the shielded wire form an electromagnetic interference resistant structure;

[0012] The interior of the temperature measurement end is filled with inorganic insulating material; the space between the leads of the thermal resistance element and the space between the high-temperature resistant wires are filled with high-temperature inorganic glue to composite the leads of the thermal resistance element, the high-temperature resistant wires, and the metal protective outer tube into one body; the interior of the sealed connection end is filled with high-temperature insulating sealant to composite the sealed connection end, the welding point of the high-temperature resistant wire and the high-temperature signal cable into one body and achieve sealing.

[0013] In an embodiment of the present invention, the small end of the variable cross-section sleeve is welded to the outer shell of the first-section metal tube by circumferential welding, and the large end is connected to the second-section metal tube by a crimping process.

[0014] In an embodiment of the present invention, one end of the sealed connection end is welded to the second-section metal tube by circumferential welding, and the other end is crimped to the shielded wire of the high-temperature signal cable by a crimping process.

[0015] In an embodiment of the present invention, the high-temperature insulating sealant is filled before the sealed connection end is crimped to the shielded wire, and the crimping process is completed before the high-temperature insulating sealant dries, so that the high-temperature insulating sealant wraps the welding point of the high-temperature resistant wire and the high-temperature signal cable; when the high-temperature insulating sealant dries, the sealed connection end, the high-temperature resistant wire, and the welding point of the high-temperature signal cable are composite into one body.

[0016] In an embodiment of the present invention, the materials of the metal protective outer tube and the sealed connection end both include stainless steel.

[0017] In an embodiment of the present invention, the number of the thermal resistance elements is greater than or equal to 2;

[0018] The thermal resistance element includes one or more of Pt100, Pt1000, and Pt2000;

[0019] The high-temperature resistant wires and high-temperature signal cables corresponding to the thermal resistance elements include two-wire system, three-wire system, or four-wire system.

[0020] In an embodiment of the present invention, the high-temperature resistant wire includes a first core wire layer and a first insulating layer wrapped outside the first core wire layer, wherein,

[0021] the material of the first core wire layer includes nickel or nickel alloy;

[0022] the material of the first insulating layer includes glass fiber or ceramic fiber.

[0023] In an embodiment of the present invention, the high-temperature signal cable includes a second core wire layer and a second insulating layer wrapped outside the second core wire layer, wherein the material of the second core wire layer includes silver-plated copper or nickel-plated copper; the material of the second insulating layer includes fluorinated ethylene propylene copolymer;

[0024] A shielding layer and a third insulating layer are sequentially wrapped outside a plurality of the high-temperature signal cables, wherein the shielding layer is formed by weaving metal wires, and the shielding layer at the end of the high-temperature signal cable is exposed to form the shielding wire; the material of the third insulating layer includes fluorinated ethylene propylene copolymer.

[0025] In an embodiment of the present invention, the inorganic insulating material includes one or more of magnesium oxide, aluminum oxide, and silicon dioxide;

[0026] The high-temperature inorganic glue includes a magnesium oxide insulating material mixed with a water glass slurry;

[0027] The high-temperature insulating sealant is an organic glue, and the service temperature is greater than 200 °C.

[0028] In an embodiment of the present invention, a ferrule is sleeved on the equal cross-section section of the variable cross-section sleeve, and the ferrule is used to connect the interface to be measured;

[0029] There is a section of bending on the second section of the metal pipe.

[0030] Compared with the prior art, the beneficial effects of the present invention:

[0031] The temperature sensor of the present invention uses a thermal resistance element as the temperature measuring element. Compared with a thermocouple temperature sensor, it has higher temperature measurement accuracy and precision. It adopts a metal protective outer tube, which can not only ensure the stability and reliability of the performance of the temperature sensor, meet the sealing performance in case of a water loss accident on the ship, but also form an anti-electromagnetic interference structure with the sealed connection end and the shielded wire, isolating the thermal resistance element and the high-temperature resistant wire from the outside, preventing electromagnetic interference and radio frequency interference. It adopts a variable cross-section sleeve, which can improve the thermal response time without reducing the overall strength of the temperature sensor. Inorganic insulating material is filled at the temperature measurement end, which can not only improve the performance of the temperature sensor against mechanical vibration, impact, etc., but also improve the thermal response time. The leads of the thermal resistance element, the high-temperature resistant wire, and the metal protective outer tube are compounded into one by high-temperature inorganic glue, which can improve the mechanical properties of the temperature sensor against vibration, impact, bump, tilt and swing, etc. The welded points of the sealed connection end, the high-temperature resistant wire and the high-temperature signal cable are compounded into one by high-temperature insulating sealant, which can improve the performance of the temperature sensor against mechanical vibration, impact and insulation sealing, etc., and can also work in a high-temperature environment. Therefore, this temperature sensor can work in a high-temperature environment for a long time, can withstand certain margins of vibration, impact, bump, tilt and swing, etc., has good mechanical properties, while ensuring a thermal response time that meets the requirements, has relatively high temperature measurement accuracy and precision, and has a long service life. Description of the Drawings

[0032] Figure 1 FIG. is a schematic structural diagram of a temperature sensor for a marine engine provided by an embodiment of the present invention;

[0033] Figure 2 FIG. is a schematic layout diagram of a thermal resistance element in a metal protective outer tube provided by an embodiment of the present invention. Detailed Embodiments

[0034] The following further describes the present invention in detail with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0035] Embodiment 1

[0036] Please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic structural diagram of a temperature sensor for a marine engine provided by an embodiment of the present invention, Figure 2 and which is a schematic layout diagram of a thermal resistance element in a metal protective outer tube provided by an embodiment of the present invention.

[0037] The temperature sensor in this embodiment is used for a ship engine and monitors the temperature on the engine. It includes a metal protection outer tube 1, a thermal resistance element 2, a high-temperature resistant wire 3, and a high-temperature signal cable 4. Among them, the metal protection outer tube 1 is formed by sequentially connecting a first-section metal tube 11, a variable cross-section sleeve 12, and a second-section metal tube 13. A sealing connection end 14 is welded to the end of the second-section metal tube 13; the thermal resistance element 2 is arranged at the end of the first-section metal tube 11 to form a temperature measurement end, and the temperature measurement end realizes pressure-bearing sealing; the small end of the variable cross-section sleeve 12 is close to the temperature measurement end; the high-temperature resistant wire 3 extends from the first-section metal tube 11, the variable cross-section sleeve 12, and the second-section metal tube 13 to the sealing connection end 14; one end of the high-temperature resistant wire 3 is welded to the thermal resistance element 2, and the other end is welded to one end of the high-temperature signal cable 4, and the welding point is located inside the sealing connection end 14; the high-temperature signal cable 4 connects the end of the high-temperature resistant wire 3 to form a shielded wire 41, and the shielded wire 41 exposes the sealing connection end 14; the metal protection outer tube 1, the sealing connection end 14, and the shielded wire 41 form an electromagnetic interference-resistant structure; the inside of the temperature measurement end is filled with an inorganic insulating material; the spaces between the leads of the thermal resistance element 2 and the spaces between the high-temperature resistant wires 3 are filled with a high-temperature inorganic glue to composite the leads of the thermal resistance element 2, the high-temperature resistant wires 3, and the metal protection outer tube 1 into one body; the inside of the sealing connection end 14 is filled with a high-temperature insulating sealant to composite the sealing connection end 14, the welding point of the high-temperature resistant wire 3, and the high-temperature signal cable 4 into one body and achieve sealing.

[0038] Specifically, the temperature sensor is formed by compounding multiple thermal resistance elements 2 in a metal protection outer tube 1. The thermal resistance element 2 is arranged in the metal protection outer tube 1 to form a temperature measurement end. The thermal resistance element 2 and the high-temperature resistant wire 3 are connected together by laser welding, and the high-temperature resistant wire 3 and the high-temperature signal cable 4 are connected together by resistance welding. After the thermal resistance element 2 receives the temperature on the engine, it transmits the resistance signal to the monitoring system through the high-temperature resistant wire 3 and the high-temperature signal cable 4. The position of the thermal resistance element 2 inside the temperature measurement end is defined as the measurement point, that is, the temperature measurement end is located at the end of the metal protection outer tube 1, and the measurement point is located inside the metal protection outer tube 1. The temperature measurement end of the metal protection outer tube 1 realizes pressure-bearing sealing by means of head welding. Exemplarily, the temperature measurement end is welded and sealed by argon arc welding.

[0039] In a specific embodiment, the number of thermal resistance elements 2 is greater than or equal to 2, and multiple thermal resistance elements 2 are arranged at the same height position of the temperature measurement end of the metal protection outer tube; the thermal resistance element 2 includes one or more of Pt100, Pt1000, and Pt2000. The number of high-temperature resistant wires 3 and high-temperature signal cables 4 is the same, and is twice, three times, or four times the number of thermal resistance elements 2 in the temperature sensor, that is, the high-temperature resistant wire 3 and the high-temperature signal cable 4 corresponding to one thermal resistance element 2 include two-wire system (two core wires), three-wire system (three core wires), or four-wire system (four core wires).

[0040] Around the thermal resistance element 2, the head welding joint from the thermal resistance element 2 to the temperature measurement end is filled with an inorganic insulating material, that is, the inside of the temperature measurement end is filled with an inorganic insulating material. In a specific embodiment, the inorganic insulating material includes one or more of magnesium oxide, aluminum oxide, and silicon dioxide; according to different service temperatures of the high-temperature resistant wire, the selected inorganic insulating material is also different. The inorganic insulating material can not only improve the performance of the temperature sensor against mechanical vibration, impact, etc., but also improve the thermal response time.

[0041] Inside the metal protective outer tube 1, the gaps between the leads of the thermal resistance element 2 and the gaps between the high-temperature resistant wires 3 are filled with a high-temperature inorganic adhesive. The function of the high-temperature inorganic adhesive is to ensure that the leads of the thermal resistance element 2, the high-temperature resistant wires 3, and the metal protective outer tube 1 are combined into one body, improving the mechanical properties of the temperature sensor against vibration, impact, bump, tilt, and sway. In a specific embodiment, the high-temperature inorganic adhesive includes a magnesium oxide insulating material mixed with a water glass slurry.

[0042] A section of variable cross-section sleeve 12 is provided at the position of the metal protective outer tube 1 close to the temperature measurement end, dividing the metal protective outer tube 1 into three sections: the first section of metal tube 11, the variable cross-section sleeve 12, and the second section of metal tube 13. The thermal resistance element 2 (temperature measurement end) is located at the end of the first section of metal tube 11, and the high-temperature resistant wire 3 extends sequentially through the first section of metal tube 11, the variable cross-section sleeve 12, and the second section of metal tube 13.

[0043] The variable cross-section sleeve 12 includes a variable cross-section section 121 and an equal cross-section section 122. The variable cross-section section 121 is close to the temperature measurement end and the small end of the variable cross-section section 121 is connected to the first section of metal tube 11, and the equal cross-section section 122 is close to the second section of metal tube 13 and is connected to the second section of metal tube 13. It can be understood that the small end of the variable cross-section sleeve 12 is connected to the first section of metal tube 11 and the large end is connected to the second section of metal tube 13.

[0044] In a specific embodiment, the small end of the variable cross-section sleeve 12 is welded (for example, laser welding) to the outer shell of the first section of metal tube 11, and the large end is connected to the second section of metal tube 13 by a crimping process. By means of crimping, it is ensured that the variable cross-section sleeve 12 is firmly fixed on the metal protective outer tube 1. To ensure the sealing quality, the ring welding tightness between the variable cross-section sleeve 12 and the metal protective outer tube 1 must be guaranteed.

[0045] Exemplarily, the distance from the small end of the variable cross-section of the variable cross-section sleeve 12 to the crimping position of the ferrule is 84 mm, and the length of the large end crimped to the second section of metal tube 13 is 5 mm. The diameter of the small end of the variable cross-section sleeve 12 is 3.2 mm, and the diameter of the large end is 4.5 mm.

[0046] In this embodiment, the variable cross-section sleeve and the metal protection outer tube are connected by crimping, making the connection between the two more firm and ensuring the safety and reliability of the sensor under the operating environmental conditions.

[0047] A sealed connection end 14 is welded near the wiring end of the metal protection outer tube 1. Here, the wiring end refers to the welding point of the high-temperature resistant wire 3 and the high-temperature signal cable 4. The function of the sealed connection end 14 is to reinforce the connection performance between the high-temperature resistant wire 3 and the high-temperature signal cable 4, ensure the stable and reliable connection between the high-temperature resistant wire 3 and the high-temperature signal cable 4 here, and ensure that the resistance signal monitored by the thermal resistance element 2 can be stably and reliably transmitted to the monitoring system through the high-temperature resistant wire 3 and the high-temperature signal cable 4. Exemplarily, the distance between the end of the sealed connection end 14 near the high-temperature resistant wire 3 and the wiring end is 12 mm.

[0048] In a specific embodiment, one end of the sealed connection end 14 is welded to the second metal tube 13 by circumferential welding (such as laser welding), and the other end is crimped onto the shield wire 41 of the high-temperature signal cable 4. Exemplarily, the crimping length is 5 mm.

[0049] It should be emphasized that all welding points in this embodiment need to be sealed to ensure the sealing performance between the sensor and the interface and the integrity of the sensor.

[0050] The material of the sealed connection end 14 is a metal material. In this way, the metal protection outer tube 1, the sealed connection end 14, and the shield wire 41 form an anti-electromagnetic interference structure. In a specific embodiment, the materials of the metal protection outer tube 1 and the sealed connection end 14 both include stainless steel, such as Inconel600 stainless steel; using stainless steel materials can ensure that the performance of the temperature sensor is more stable and reliable, and ensure the sealing performance when a water loss accident occurs on the ship.

[0051] To ensure the insulation performance of the temperature sensor, the sealed connection end 14 and the shield wire 41 are filled with high-temperature insulating sealant before crimping; before the high-temperature insulating sealant dries, the crimping process is completed so that the high-temperature insulating sealant completely wraps the welding point of the high-temperature resistant wire 3 and the high-temperature signal cable 4, and at the same time ensures the sealing performance of the sealed connection end 14; after the high-temperature insulating sealant dries, the connection part of the sealed connection end 14, the high-temperature resistant wire 3, and the high-temperature signal cable 4 is compounded into one body here, improving the performance of the temperature sensor against mechanical vibration, impact, and insulation sealing. In a specific embodiment, the high-temperature insulating sealant is an organic glue, with a service temperature greater than 200 °C, and still having good insulation and sealing performance when used at temperatures above 200 °C for a long time.

[0052] In a specific embodiment, the high-temperature resistant wire 3 serves as a signal transmission line and includes a first core wire layer and a first insulating layer wrapped around the first core wire layer. Among them, the material of the first core wire layer includes nickel or nickel alloy. Exemplarily, the cross-sectional area of the first core wire layer is 4×0.5mm 2 ; the material of the first insulating layer includes glass fiber or ceramic fiber. The insulating layer material ensures that the sensor still has insulating properties at a high temperature of 700°C. Further, the first insulating layers corresponding to the same resistance element have the same color.

[0053] In this embodiment, the core wire layer material of the high-temperature resistant wire 3 is selected as nickel or nickel alloy, which can ensure that the leads of the thermal resistance elements have good welding performance and low resistance values with the high-temperature resistant wire, and can ensure the service life of the temperature sensor. The insulating layer material is selected as glass fiber or ceramic fiber, which can ensure that the temperature sensor still has good insulating properties at high temperatures.

[0054] In a specific embodiment, the high-temperature signal cable 4 includes a second core wire layer and a second insulating layer wrapped around the second core wire layer. Among them, the material of the second core wire layer includes silver-plated copper or nickel-plated copper; the material of the second insulating layer includes fluorinated ethylene propylene copolymer. A shielding layer and a third insulating layer are sequentially wrapped outside the plurality of high-temperature signal cables 4. Among them, the shielding layer is formed by weaving metal wires, and the shielding layer at the end of the high-temperature signal cable 4 is exposed to form a shielding wire 41; the material of the third insulating layer includes fluorinated ethylene propylene copolymer.

[0055] Specifically, the high-temperature signal cable 4 serves as a signal transmission line, and from the inside to the outside, there are a second core wire layer and a second insulating layer in sequence. Exemplarily, the cross-sectional area of the second core wire layer is 4×0.5mm 2 . The second insulating layer uses FEP, and its function is to insulate the core wire materials from each other. The second insulating layer uses the same color to represent the leads of the same component, and several colors indicate how many thermal resistance elements the sensor has.

[0056] A shielding layer and a third insulating layer are sequentially wrapped outside the plurality of high-temperature signal cables 4. At the connection between the high-temperature signal cable 4 and the high-temperature resistant wire 3, the shielding layer is exposed to form a shielding wire 41, the shielding wire 41 exposes the sealed connection end 14, and the sealed connection end 14 is crimped on the shielding wire 41. The setting of the shielding layer and the crimping method of the shielding layer can prevent electromagnetic interference and radio frequency interference, enabling the temperature sensor to have good electromagnetic interference resistance and ensuring the accuracy and reliability of the sensor signal. A layer of FEP insulating material is laid outside the shielding layer as the third insulating layer. The function of this layer of FEP insulating material is to wrap the core wire, the second insulating layer outside the core wire, and the shielding layer together, making the temperature sensor keep the shell insulated. Even under the condition of a loss-of-coolant accident, it still has good insulating properties and continues to perform its monitoring function. At the same time, this layer of FEP insulating material can ensure that the overall cable can withstand a high temperature of 200°C.

[0057] In a specific embodiment, a ferrule 5 is sleeved on the equal cross-section section 122 of the variable cross-section sleeve 12, and the ferrule 5 is used to connect the interface to be measured.

[0058] Specifically, the function of the ferrule 5 is to match the corresponding temperature measurement interface on the engine, and the position of the ferrule determines the position where the temperature sensor is sealed with the interface. The ferrule 5 has a G1 / 4A thread, and the G1 / 4A thread is sealed with the corresponding interface on the engine through a washer. The other end of the ferrule 5 has a ferrule cap. By tightening the ferrule cap on the ferrule 5, the balls in the ferrule 5 are deformed on the variable cross-section sleeve, and the variable cross-section sleeve is clamped, thus completing the sealing of the ferrule 5 with the temperature sensor used on the marine engine.

[0059] Exemplarily, the distance from the G1 / 4A thread seal of the ferrule 5 to the head welding is 82 mm.

[0060] In a specific embodiment, in order to facilitate the routing of the temperature sensor in the interface to be measured, a bend 131 is provided on the second metal tube 13, and the position, angle and length of the bend 131 can be set according to the actual installation requirements.

[0061] Exemplarily, at a distance of 123 mm from the head welding of the temperature measurement end of the second metal tube 13, there is a bend with an R of 20, and the bend length is 31.4 mm.

[0062] The temperature sensor of this embodiment is made into a temperature sensor for marine engines that meets the requirements according to the position and bending radius to be bent after passing through processes such as blanking, welding, crimping, positioning, potting, continuity detection, and insulation detection. After re-checking the graduation and insulation performance and passing the inspection, the production of the temperature sensor for marine engines is completed.

[0063] Between the thermal resistance element 2 in the temperature measurement end of the temperature sensor of this embodiment and the first metal tube 11 is of the insulated type. The normal temperature insulation performance of the thermal resistance element is greater than 100 GΩ (measurement voltage 500 VDC), and the measurement accuracy is Class A accuracy (R 0红-红 = 999.752 Ω, R 0白-白 = 999.998 Ω; R 100红-红 = 1384.486 Ω, R 100白-白 = 1384.555 Ω), R 100红-红 / R 0红-红 = 1.384829, R 100白-白 / R 0白-白 = 1.384558, the thermal response time is less than τ 0.5红-红 = 1.8 s, τ 0.5白-白= 1.9 s. The welded and sealed structure ensures that the sealing performance of the sensor meets the IP65 protection level. This temperature sensor is of the double-element type, that is, it has two thermal resistance elements, R 0红-红 is the resistance value at 0 °C of a set of thermal resistance elements with the high-temperature signal cable lead marked red; R 0白-白 is the resistance value at 0 °C of another set of thermal resistance elements with the high-temperature signal cable lead marked white; R 100红-红 is the resistance value at 100 °C of a set of thermal resistance elements with the high-temperature signal cable lead marked red; R 100白-白 is the resistance value at 100 °C of a set of thermal resistance elements with the high-temperature signal cable lead marked white; R 100红-红 / R 0红-红 is the ratio of the resistance value at 100 °C to the resistance value at 0 °C of a set of thermal resistance elements with the high-temperature signal cable lead marked red; R 100白-白 / R 0白-白 is the ratio of the resistance value at 100 °C to the resistance value at 0 °C of a set of thermal resistance elements with the high-temperature signal cable lead marked white; τ 0.5红-红 is the thermal response time of a set of thermal resistance elements with the high-temperature signal cable lead marked red under the 0.5 coefficient condition; τ 0.5白-白 is the thermal response time of a set of thermal resistance elements with the high-temperature signal cable lead marked white under the 0.5 coefficient condition; IP65 is a level in the protection level standard IEC60529 formulated by the International Organization for Standardization, indicating that the device can be used outdoors or in places where water splashes frequently.

[0064] The temperature sensor in this embodiment has accurate and reliable temperature measurement, strong voltage resistance, and stable monitoring signals, and can be used in the temperature range of 0 °C to 700 °C.

[0065] The temperature sensor of this embodiment uses a thermal resistance element as the temperature measuring element, which has higher temperature measuring accuracy and precision compared with a thermocouple temperature sensor. It adopts a metal protective outer tube, which can not only ensure the stability and reliability of the temperature sensor performance and meet the sealing performance in case of a water loss accident on the ship, but also form an anti-electromagnetic interference structure with the sealed connection end and the shielded wire, isolating the thermal resistance element and the high-temperature resistant wire from the outside world to prevent electromagnetic interference and radio frequency interference. It adopts a variable cross-section sleeve, which can improve the thermal response time without reducing the overall strength of the temperature sensor. Inorganic insulating material is filled at the temperature measurement end, which can not only improve the anti-mechanical vibration, impact and other performances of the temperature sensor, but also improve the thermal response time. The leads of the thermal resistance element, the high-temperature resistant wire and the metal protective outer tube are compounded into one body through high-temperature inorganic glue, which can improve the mechanical performances of the temperature sensor such as anti-vibration, impact, bump, tilt and swing. The welded points of the sealed connection end, the high-temperature resistant wire and the high-temperature signal cable are compounded into one body through high-temperature insulating sealant, which can improve the anti-mechanical vibration, impact and insulation sealing performances of the temperature sensor and can also work in a high-temperature environment. Therefore, this temperature sensor can work in a high-temperature environment for a long time, can withstand certain margins of vibration, impact, bump, tilt and swing and other conditions, has good mechanical performances, can ensure a thermal response time that meets the requirements, has relatively high temperature measuring accuracy and precision, has a long service life and low cost, and can meet different environmental requirements.

[0066] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A temperature sensor for a ship engine, characterized in that: include: A metal protective outer tube (1), a thermal resistance element (2), a high temperature resistant wire (3) and a high temperature signal cable (4), wherein: The metal protective outer tube (1) is formed by sequentially connecting a first section of a metal tube (11), a sleeve with a variable cross-section (12), and a second section of a metal tube (13); a sealed connection end (14) is welded to the end of the second section of the metal tube (13); The thermal resistance element (2) is arranged at the end of the first section of the metal tube (11) to form a temperature measuring end, and the temperature measuring end realizes pressure-bearing sealing; the small end of the variable-section sleeve (12) is close to the temperature measuring end; The high temperature resistant wire (3) extends from the first section of the metal tube (11), the variable cross-section sleeve (12), and the second section of the metal tube (13) to the sealed connection end (14); one end of the high temperature resistant wire (3) is welded to the thermal resistance element (2), and the other end is welded to one end of the high temperature signal cable (4), and the welding point is located inside the sealed connection end (14); The plurality of high-temperature signal cables (4) are wrapped with a shielding layer and a third insulating layer in sequence, the shielding layer of the end of the high-temperature signal cable (4) connected to the high-temperature resistant wire (3) is exposed and the sealed connection end (14) is exposed to form the shielding wire (41), and the shielding layer is formed by braiding metal wires; the metal protective outer tube (1), the sealed connection end (14) and the shielding wire (41) form an anti-electromagnetic interference structure; The interior of the temperature measuring end is filled with an inorganic insulating material; the gaps between the leads of the thermal resistor element (2) and the gaps between the high-temperature resistant wires (3) are filled with high-temperature inorganic glue to composite the leads of the thermal resistor element (2), the high-temperature resistant wires (3) and the metal protective outer tube (1) into one; the interior of the sealed connection end (14) is filled with a high-temperature insulating sealant to composite the welding points of the sealed connection end (14), the high-temperature resistant wires (3) and the high-temperature signal cable (4) into one and achieve sealing.

2. The temperature sensor for a ship engine according to claim 1, characterized in that: The small end of the variable cross-section sleeve (12) is welded to the outer shell of the first section metal pipe (11) by ring welding, and the large end is connected to the second section metal pipe (13) by a crimping process.

3. The temperature sensor for a ship engine according to claim 1, characterized in that: One end of the sealed connection end (14) is welded to the second section of the metal tube (13) by ring welding, and the other end is crimped onto the shielding wire (41) of the high-temperature signal cable (4) by a crimping process.

4. The temperature sensor for a ship engine according to claim 3, characterized in that: The high-temperature insulating sealant is filled before the sealed connection end (14) and the shielding wire (41) are crimped, and the crimping process is completed before the high-temperature insulating sealant dries, so that the high-temperature insulating sealant wraps the welding points of the high-temperature resistant wire (3) and the high-temperature signal cable (4); when the high-temperature insulating sealant dries, the sealed connection end (14), the high-temperature resistant wire (3) and the welding points of the high-temperature signal cable (4) are combined into one.

5. The temperature sensor for a ship engine according to claim 1, characterized in that: The materials of the metal protective outer tube (1) and the sealing connection end (14) both include stainless steel.

6. The temperature sensor for a ship engine according to claim 1, characterized in that: The number of the thermal resistance elements (2) is greater than or equal to 2; The thermal resistance element (2) includes one or more of Pt100, Pt1000, and Pt2000; The high temperature resistant wire (3) and the high temperature signal cable (4) corresponding to the thermal resistance element (2) include a two-wire system, a three-wire system or a four-wire system.

7. The temperature sensor for a ship engine according to claim 1, characterized in that: The high temperature resistant wire (3) comprises a first core wire layer and a first insulating layer wrapped outside the first core wire layer, wherein: The material of the first core wire layer includes nickel or nickel alloy; The material of the first insulating layer includes glass fiber or ceramic fiber.

8. The temperature sensor for a ship engine according to claim 1, characterized in that: The high-temperature signal cable (4) comprises a second core layer and a second insulating layer wrapping the second core layer, wherein the material of the second core layer comprises silver-plated copper or nickel-plated copper; the material of the second insulating layer comprises fluorine-ethylene-propylene copolymer; The outer shielding layers of the plurality of high-temperature signal cables (4) are formed by braiding metal wires, and the material of the third insulating layer includes fluorinated ethylene propylene copolymer.

9. The temperature sensor for a ship engine according to claim 1, characterized in that: The inorganic insulating material includes one or more of magnesium oxide, aluminum oxide, and silicon dioxide; The high temperature inorganic glue comprises magnesium oxide insulating material mixed with water glass slurry; The high temperature insulating sealant is an organic sealant with a use temperature greater than 200°C.

10. The temperature sensor for a ship engine according to claim 1, characterized in that: The equal-section section (122) of the variable-section sleeve (12) is sleeved with a ferrule (5), and the ferrule is used to connect to the interface to be tested; The second section of the metal tube (13) has a bend (131).

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