A through needle temperature pressure sensor and assembly process

Abstract

The application discloses a through-needle temperature and pressure sensor and an assembling process, relates to the technical field of temperature and pressure sensors, and the sensor comprises a ceramic pressure core body and an NTC assembly. The ceramic pressure core body is provided with an NTC through-needle for temperature signal output. The NTC assembly comprises an NTC chip, a lead sleeve, a fixing seat and a metal sheath. The lead sleeve of the NTC chip is arranged in the lead sleeve and extends out through the fixing seat. The metal sheath is arranged outside the lead sleeve and the NTC chip and is fixed to the fixing seat. The lead of the NTC chip is connected with the NTC through-needle through resistance welding, the connection reliability is improved, and solder pine splashing pollution to the fixing seat and the ceramic pressure core body is avoided. Through lead arrangement, metal sheath protection and direct connection through resistance welding, the temperature and pressure sensor structure is simplified, the electrical connection reliability is improved, and the signal path is rationalized. The problems of complex structure, circuit virtual connection and low reliability in the existing temperature and pressure sensor are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature and pressure sensors, in particular to a through-needle temperature and pressure sensor and an assembling process. BACKGROUND

[0002] The existing temperature and pressure sensors generally adopt a ceramic capacitor core and a metal diaphragm to form a pressure sensing unit, and adopt an NTC or a thermistor to form a temperature collecting unit, and then realize signal transmission through a flexible circuit board, a metal through-needle or a lead wire. However, under the trend of multi-parameter integration, the existing scheme generally faces problems such as complex structure, many sealing points, insufficient mechanical strength and unreliable temperature probe installation.

[0003] The existing technical scheme adopts the following four structures: an annular ceramic capacitor core, a temperature sensing element passing through the core shaft hole and forming independent pressure cavities in the inner and outer rings. Due to the limitation of the inner cavity, the metal diaphragm must be very thin to ensure sufficient deformation space, and the strength and fatigue reliability are significantly reduced. At the same time, the scheme transmits the temperature signal through the welding point and the lead wire perforation structure, lacks effective lead wire fixing measures, and is easily caused by vehicle vibration or pressure pulse impact for a long time. The welding point is loose and fails. In addition, the scheme adopts up to three static sealing rings, and the sealing surface ages quickly under temperature cycling and medium pressure fluctuation, with high risk of leakage.

[0004] A metal sleeve and a temperature element carrier are connected by pressure riveting or thermal riveting, and multiple sealing rings are used to realize radial sealing, and then combined and packaged with a ceramic capacitor core and a flexible circuit board. In this structure, the temperature pin is exposed to the outside, which is easy to be corroded and contaminated by the medium, and the riveting process of the metal sleeve may also cause local stress concentration on the plastic or metal carrier, reducing the overall durability. Further, due to the cavity between the metal sleeve and the temperature element, the thermal response speed is limited, and the sleeve is easy to deform plastically under high pressure, which extrudes the sealing ring and causes sealing failure.

[0005] A flexible circuit board is used to connect the ceramic core and the NTC assembly, three sealing rings are used to ensure the system sealing, and a metal protective sleeve is connected with the sensor shell by laser welding or argon arc welding. The disadvantages are that the multi-sealing point structure is complex and the sealing ring wears out and fails after long-term operation; the heat affected zone caused by the thermal welding process may change the material properties and cause stress concentration in the welding area, affecting the structural reliability.

[0006] A ceramic substrate and a diaphragm are combined to form a through channel, and the temperature assembly is packaged by epoxy after tin soldering of the through-needle. Since the tin soldering has limited bonding strength of the pin and the through-needle, and the soldering process is easy to cause rosin pollution, long-term use may cause loose connection of the soldering point, resistance drift or aging of the sealing interface, thereby affecting the temperature collection accuracy and the overall life of the sensor.

[0007] In summary, it is found that the prior art at least has the following technical problems:

[0008] The existing temperature pressure sensor has the technical problems of complex structure, poor reliability, virtual connection of circuit and unreasonable circuit path, resulting in low sealing reliability, low durability and signal distortion. SUMMARY

[0009] The purpose of the present application is to provide a through-needle temperature pressure sensor and an assembly process to solve the technical problems of the existing temperature pressure sensor, such as complex structure, poor reliability, virtual connection of circuit and unreasonable circuit path, resulting in low sealing reliability, low durability and signal distortion.

[0010] The preferred technical solutions in the many technical solutions provided by the present application can produce many technical effects, which are described in detail below.

[0011] In order to solve the above technical problems, the present application provides the following technical solutions:

[0012] The present application provides a through-needle temperature pressure sensor, comprising a ceramic pressure core and an NTC assembly; an NTC through-needle for temperature signal output is provided on the ceramic pressure core; the NTC assembly comprises an NTC chip, a lead sleeve, a fixing seat and a metal sheath; the NTC chip is located at one end of the lead sleeve, the lead of the NTC chip is sleeved in the lead sleeve and extends out of the other end of the lead sleeve according to the shape of the lead sleeve; the lead sleeve is installed on the fixing seat and the lead of the NTC chip is regularized into the fixing seat; the metal sheath is sleeved outside the lead sleeve and the NTC chip and is fixed on the fixing seat; the lead of the NTC chip is welded and connected with one end of the NTC through-needle towards the fixing seat by resistance welding, so as to realize the splash-free pollution welding of the lead between the fixing seat and the ceramic pressure core and the NTC through-needle.

[0013] In one embodiment, the ceramic pressure core comprises any one of a resistance type pressure core and a capacitance type pressure core.

[0014] In one embodiment, a PIN needle for pressure signal output is further provided on the ceramic pressure core; the other end of the PIN needle and the other end of the NTC through-needle are both used for connecting with a to-be-installed circuit board, for outputting pressure signal and temperature signal to the circuit board.

[0015] In one embodiment, heat-conducting glue is injected between the NTC chip and the metal sheath to bond the fixing seat and the metal sheath, so as to improve temperature measurement sensitivity and buffer protect the NTC chip.

[0016] In one embodiment, the lead wire of the NTC chip is welded with the welding spot of the NTC needle, and the welding spot is filled with potting glue outside the welding spot, so as to protect the welding spot by curing the potting glue, and improve the stability and reliability of the welding spot.

[0017] In one embodiment, the fixing seat is provided with two opposite potting grooves, the lead wire of the NTC chip and the welding spot of the NTC needle are covered by the two potting grooves, the potting grooves are connected with the space surrounded by the fixing seat and the ceramic pressure core, and the potting glue is filled in the potting grooves and the space surrounded by the fixing seat and the ceramic pressure core, so as to seal the fixing seat and bond the fixing seat and the ceramic pressure core.

[0018] In one embodiment, the fixing seat is provided with two opposite pressure channels, the NTC chip, the lead wire of the NTC chip and the welding spot of the NTC needle are respectively sealed by the heat-conducting glue and the potting glue, and the liquid or gas to be measured is introduced into the measuring side of the ceramic pressure core through the pressure channels.

[0019] In one embodiment, the fixing seat is provided with a positioning column extending vertically upward towards the axis center of the metal sheath, the side wall of the positioning column is provided with oppositely arranged convex buckle blocks, the side wall of the convex buckle block corresponding to the metal sheath is also provided with a buckle hole, the axis center of the positioning column is provided with a mounting cavity, the side wall of the positioning column is provided with two oppositely arranged mounting grooves, the mounting grooves are connected with the mounting cavity, the mounting sleeve of the lead wire sleeve is mounted in the mounting cavity, the lead wire of the NTC chip extends out of the mounting grooves and enters the potting groove, the metal sheath is sleeved outside the positioning column, the convex buckle block extends out of the buckle hole at the position corresponding to the buckle hole, forming a buckle positioning structure, and the buckle positioning structure connects and fixes the metal sheath and the fixing seat, so as to improve the stability of the metal sheath protecting the NTC chip.

[0020] In one embodiment, the metal sheath is provided with a wing plate extending outwardly and obliquely outside the buckle hole in the vertical direction, and the wing plate is integrally stamped with the outer wall of the metal sheath; when the finished product shell is mounted outside the metal sheath, the wing plate contacts the finished product shell to form a grounding, so as to improve the stability and accuracy of the temperature signal output by the lead wire of the NTC chip.

[0021] Also provided is an assembly process of a through-needle temperature and pressure sensor, comprising the through-needle temperature and pressure sensor, comprising the following steps: S1, installing an NTC chip and a lead wire into a lead wire sleeve, and installing the lead wire sleeve on a fixed seat, so that the lead wire of the NTC chip is regularly positioned in the fixed seat;

[0022] S2, injecting a heat-conducting glue between the NTC chip and a metal sheath, and bonding and fixing the NTC chip and buffering and protecting the NTC chip;

[0023] S3, sleeving the metal sheath outside the lead wire sleeve, connecting and fixing the metal sheath and the fixed seat through a buckle structure, and pouring potting glue;

[0024] S4, assembling the fixed seat and a ceramic pressure core body, so that one end of an NTC through needle on the ceramic pressure core body and a PIN needle are arranged towards a direction of a circuit board to be installed;

[0025] S5, welding the lead wire of the NTC chip and the other end of the NTC through needle on the ceramic pressure core body through a resistance welding mode;

[0026] S6, pouring potting glue in a pouring groove, so that the potting glue covers a welding point of the lead wire of the NTC chip and a space surrounded by the assembly of the fixed seat and the ceramic pressure core body, and a secondary sealing layer is formed after solidification, so as to complete the assembly of the through-needle temperature and pressure sensor.

[0027] The beneficial effects of the present application are as follows:

[0028] Firstly, the present application adopts a split structure of a ceramic pressure core body and an NTC assembly, and an NTC through needle for temperature signal output is arranged on the ceramic pressure core body, so that a temperature acquisition path and a pressure acquisition path are independent of each other, and the problems of complex structure, difficult wiring and limited diaphragm space caused by the arrangement of a temperature lead wire through a narrow cavity in a traditional ring-shaped ceramic core body are avoided, thereby improving the overall structural stability.

[0029] Secondly, the present application effectively regularizes and positions the lead wire of the NTC chip before entering a welding area through the arrangement of the lead wire sleeve and the fixed seat, avoids the risk of virtual connection caused by the floating, twisting or swinging of the lead wire due to vibration, and significantly improves the stability of the temperature signal output; the double protection structure of the lead wire sleeve and the metal sheath further improves the mechanical protection capability and durability of the lead wire.

[0030] Thirdly, the present application adopts resistance welding to weld the lead wire of the NTC chip and the NTC through needle of the ceramic pressure core body, the resistance welding does not produce metal sputtering, the risk of contamination of the electrode surface or the internal cavity of the ceramic core body by the welding point is greatly reduced compared with traditional tin welding, the welding strength is high, the welding point consistency is good, the reliability of the electrical connection between the electronic elements in the temperature and pressure sensor is effectively improved, and the signal distortion caused by the falling or virtual welding of the welding point is avoided.

[0031] In addition, the metal sheath is sleeved outside the lead sleeve and the NTC chip, and is fixed to the fixed seat, so that the overall rigid protection of the NTC chip is realized, and the impact resistance and vibration resistance are improved; the structure makes the temperature collection path more reasonable and clear, effectively avoids the hidden troubles such as electric leakage, corrosion or short circuit caused by exposed lead, and thus obviously improves the service life and safety of the sensor.

[0032] To sum up, through the lead sleeve regular structure, the resistance welding process, the metal sheath protection structure and the through needle type temperature signal leading-out mode, the problems of complex structure, poor sealing reliability, circuit virtual connection and signal distortion in the existing temperature pressure sensor are successfully solved, and the comprehensive technical improvement of the temperature pressure sensor in high reliability, simplified structure, improved durability and improved signal stability is realized. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described in the following are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is the axial structure schematic diagram of the through needle temperature pressure sensor of the present application;

[0035] Figure 2 is the assembled front view structure schematic diagram of the through needle temperature pressure sensor and the circuit board of the present application;

[0036] Figure 3 is the top view structure schematic diagram of the through needle temperature pressure sensor of the present application;

[0037] Figure 4 is the bottom view structure schematic diagram of the through needle temperature pressure sensor of the present application;

[0038] Figure 5 is the perspective structure schematic diagram of the through needle temperature pressure sensor of the present application.

[0039] Among them, the reference signs are as follows:

[0040] 1, ceramic pressure core; 11, NTC through needle; 12, PIN needle; 13, measurement side;

[0041] 2, NTC assembly;

[0042] 3, NTC chip; 31, lead;

[0043] 4, lead sleeve;

[0044] 5. Fixing base; 51. Filling groove; 52. Pressure channel; 53. Positioning post; 531. Protruding fastener; 532. Mounting cavity; 533. Mounting groove;

[0045] 6. Metal sheath; 61. Buckle hole; 62. Wing plate;

[0046] 7. Circuit board. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0048] This embodiment provides a through-needle temperature and pressure sensor and its assembly process. The sensor includes a ceramic pressure core and an NTC assembly. An NTC through-needle for temperature signal output is inserted through the ceramic pressure core. The NTC assembly includes an NTC chip, a lead sleeve, a mounting base, and a metal sheath. The lead of the NTC chip is sleeved inside the lead sleeve and extends out and is neatly arranged by the mounting base. The metal sheath is sleeved outside the lead sleeve and the NTC chip and fixed to the mounting base. The lead of the NTC chip is connected to the NTC through-needle by resistance welding to avoid welding sputtering contaminating the ceramic pressure core. Through lead neatness, metal sheath protection, and resistance welding connection, the temperature and pressure sensor structure is simplified, the electrical connection reliability is improved, and the signal path is rationalized. This effectively solves the technical problems of existing temperature and pressure sensors, such as complex structure, poor sealing reliability, loose circuit connections, and unreasonable circuit paths, which lead to low sealing reliability, low durability, and signal distortion.

[0049] The first implementation of the needle temperature and pressure sensor, for example Figures 1 to 5 As shown, the device includes a ceramic pressure core 1 and an NTC assembly 2. An NTC probe 11 for temperature signal output is mounted on the ceramic pressure core 1. The NTC assembly 2 includes an NTC chip (Negative Temperature Coefficient) 3, a lead sleeve 4, a mounting base 5, and a metal sheath 6. The NTC chip 3 is located at one end of the lead sleeve 4, and the lead 31 of the NTC chip 3 is fitted inside the lead sleeve 4 and extends out of the other end of the lead sleeve 4 according to its regular shape. The lead sleeve 4 is mounted on the mounting base 5, and the lead 31 of the NTC chip 3 is neatly aligned within the mounting base 5. The metal sheath 6 is fitted over the lead sleeve 4 and the NTC chip 3 and fixed to the mounting base 5. The lead 31 of the NTC chip 3 is welded to the end of the NTC probe 11 facing the mounting base 5 via resistance welding, achieving sputter-free welding of the lead 31 between the mounting base 5 and the ceramic pressure core 1 and the NTC probe 11.

[0050] The technical scheme provides a through-needle temperature and pressure sensor, and aims at the problems of complex structure, poor sealing reliability, virtual connection of circuit and unreasonable circuit path of the existing temperature and pressure sensor, realizes multiple technical effects through structure simplification, path optimization and welding process improvement, and improves the stability, reliability and sealing performance of the temperature and pressure sensor, and the specific technical effects include: first, the technical scheme adopts a split structure of the ceramic pressure core body 1 and the NTC assembly 2, and the NTC through-needle 11 for temperature signal output is arranged on the ceramic pressure core body 1, so that the temperature acquisition path and the pressure acquisition path are independent of each other, and the problems of complex structure, wiring difficulty and limited diaphragm space caused by the temperature lead 31 passing through the narrow cavity in the traditional ring-shaped ceramic core body are avoided, thereby improving the overall structural stability.

[0051] Secondly, the technical scheme sets the lead sleeve 4 and the fixing seat 5, so that the lead 31 of the NTC chip 3 is effectively regularized and limited before entering the welding area, the risk of virtual connection caused by the floating, twisting or vibration swinging of the lead 31 is avoided, and the stability of the temperature signal output is significantly improved; the double-protection structure of the lead sleeve 4 and the metal sheath 6 further improves the mechanical protection capability and durability of the lead 31.

[0052] Thirdly, the technical scheme adopts resistance welding to weld the lead 31 of the NTC chip 3 and the NTC through-needle 11 of the ceramic pressure core body 1, the resistance welding does not produce metal sputtering, the risk of contaminating the electrode surface or the internal cavity of the ceramic core body by the welding spot is greatly reduced compared with traditional tin welding, the welding strength is high, the welding spot consistency is good, the reliability of the electrical connection between the electronic elements in the temperature and pressure sensor is effectively improved, and the signal distortion caused by the falling or virtual welding of the welding spot is avoided.

[0053] In addition, the metal sheath 6 is sleeved on the lead sleeve 4 and the NTC chip 3, and is fixed to the fixing seat 5, realizes the overall rigid protection of the NTC chip 3, and improves the impact resistance and vibration resistance; the structure makes the temperature acquisition path more reasonable and clear, effectively avoids the hidden dangers such as electric leakage, corrosion or short circuit caused by the exposure of the lead 31, and significantly improves the service life and safety of the sensor.

[0054] In summary, the technical scheme successfully solves the problems of complex structure, poor sealing reliability, virtual connection of circuit and signal distortion in the existing temperature and pressure sensor through the regularized structure of the lead sleeve 4, the resistance welding process, the protection structure of the metal sheath 6 and the through-needle temperature signal leading-out mode, realizes the comprehensive technical improvement of the temperature and pressure sensor in high reliability, simplified structure, improved durability and improved signal stability.

[0055] As one of the optional implementation manners:

[0056] Regarding the electrical connection structure of the ceramic pressure core body 1, the implementation manner is as follows:Figures 1 to 5 As shown, the ceramic pressure core 1 is further provided with a PIN needle 12 for pressure signal output; the PIN needle 12 and the other end of the NTC needle 11 are both used for connecting with the circuit board 7 to be installed, for outputting the pressure signal and the temperature signal to the circuit board 7.

[0057] In application, the PIN needle 12 and the NTC needle 11 on the ceramic pressure core 1 are jointly arranged to face the circuit board 7 to be installed, so that the pressure signal path and the temperature signal path are kept independent in structure but realize same-direction output on the external interface side. This structure can realize one-time alignment welding or plug-in connection when the sensor is installed into the finished product shell, avoiding the problems of wiring confusion and unreasonable circuit path caused by the lateral winding or the internal cavity of the temperature lead 31 in the traditional scheme.

[0058] By uniformly arranging the PIN needle 12 and the NTC needle 11 on one side of the ceramic pressure core 1 opposite to the circuit board 7, the shortest and straightest signal path can be ensured, the signal loss and interference can be significantly reduced, and the integrity and accuracy of the temperature and pressure signals in the transmission process can be improved, thereby improving the control response performance of the whole machine.

[0059] The PIN needle 12 and the NTC needle 11 are made of gold-plated, tin-plated or nickel-plated metal materials to further improve the welding adaptability and oxidation resistance; the connection mode of the PIN needle 12 and the ceramic pressure core 1 also adopts a co-firing embedded structure to improve the thermal shock resistance of the body connection.

[0060] As for the measurement type of the above-mentioned ceramic pressure core 1, the ceramic pressure core 1 includes any one of a resistance type pressure core and a capacitance type pressure core.

[0061] In application, according to the requirements of pressure response speed, range and anti-interference performance in different application scenarios, the ceramic pressure core 1 can be selected as a resistance type pressure core or a capacitance type pressure core.

[0062] The capacitance type core has the characteristics of high sensitivity and low temperature drift, and is suitable for stable working conditions such as household appliances and fluid control; while the resistance type core has higher mechanical strength and impact resistance, and is more suitable for working conditions with strong pressure pulse such as automobiles and industrial equipment.

[0063] By modularly replacing the pressure core type, the whole temperature and pressure sensor does not need to change the temperature acquisition path and structural arrangement, so that the application scenario expansion can be realized in the assembly stage, and multiple pressure detection requirements can be compatible under the condition that the temperature detection part remains unchanged, thereby improving the serialization and generalization ability of the sensor.

[0064] As for the protection structure of the above-mentioned NTC chip 3, the embodiment is as follows Figures 1 to 5As shown, the heat-conducting adhesive is injected between the NTC chip 3 and the metal sheath 6 to fix the seat 5 and the metal sheath 6, so as to improve the temperature measurement sensitivity and provide buffer protection for the NTC chip 3.

[0065] In the application, the heat-conducting adhesive is injected between the NTC chip 3 and the metal sheath 6, so that the NTC chip 3 forms a continuous heat conduction path while obtaining reliable mechanical support.

[0066] The heat-conducting adhesive not only quickly transmits the external temperature to the NTC chip 3, thereby improving the temperature measurement sensitivity and response speed, but also provides buffer protection for the NTC chip 3 under the working conditions of vibration and falling, so as to prevent the lead 31 from being bent and broken or the chip from falling off due to stress concentration. Meanwhile, the heat-conducting adhesive realizes the adhesion of the seat 5 and the metal sheath 6, so as to ensure the stability of the overall structure of the NTC chip 3, form a double-protection system with the subsequent potting adhesive, and achieve higher reliability. The structure effectively solves the problems of cavity response delay, vibration sensitivity and the like in the traditional metal sleeve.

[0067] The heat-conducting adhesive is made of silicone, epoxy resin or flexible high-thermal-conductivity material, and the thermal conductivity coefficient thereof is selected between 1-4 W / m·K according to the application environment, so as to adapt to different temperature response requirements.

[0068] Regarding the solder joint protection structure of the lead 31 of the NTC chip 3 and the NTC lead 11, the embodiment is as follows Figures 1 to 5 As shown, the solder joint of the lead 31 of the NTC chip 3 and the NTC lead 11 is injected with potting adhesive, so as to protect the solder joint by potting and curing the potting adhesive, and improve the stability of the solder joint connection and the reliability of the conduction.

[0069] Specifically, the seat 5 is provided with two opposite potting grooves 51, the two potting grooves 51 cover the lead 31 of the NTC chip 3 extending from the lead sleeve 4 and the metal sheath 6, and the solder joint of the lead 31 of the NTC chip 3 and the NTC lead 11; the potting groove 51 is communicated with the space surrounded by the seat 5 and the ceramic pressure core 1; the potting adhesive is injected into the potting groove 51 and the space surrounded by the seat 5 and the ceramic pressure core 1, so as to seal the seat 5 and adhere the seat 5 and the ceramic pressure core 1.

[0070] In the application, the lead 31 of the NTC chip 3 and the welding point of the NTC needle 11 are completely covered by the potting glue, and after the potting glue is solidified, a high-strength secondary sealing layer is formed, which can effectively block the erosion of water vapor, oil stains and corrosive gas to the welding point. The potting glue applies mechanical limiting to the welding point, so that it remains stable electrical connection under the action of running vibration and thermal cycle, avoiding the risk of false welding, cracking or welding point falling off. At the same time, the space formed by the potting groove 51 on the fixing seat 5 and the ceramic pressure core 1 is in communication, so that the potting glue is poured into and solidified to play the roles of sealing, fixing and buffering, further enhancing the mechanical strength and sealing reliability of the whole temperature collection path, solving the problems of electric leakage, corrosion and signal drift caused by the exposure of the welding point in the prior art.

[0071] The potting glue can be a flame-retardant epoxy, silicone or polyurethane type material, and according to the application requirements, reinforcing fillers or moisture-proof agents can be added to improve the environmental adaptability of the needle temperature and pressure sensor.

[0072] Regarding the structure and function of the pressure channel 52 provided on the fixing seat 5, this embodiment is shown in Figures 1 to 5 As shown in the figure, the fixing seat 5 is provided with two oppositely arranged pressure channels 52. Under the sealing protection of the heat-conducting glue and the potting glue, the liquid or gas needing to be measured introduced by the finished product shell is guided into the measuring side 13 of the ceramic pressure core 1 through the pressure channel 52.

[0073] Among them, the pressure channel 52 and the potting groove 51 are independently arranged, the pressure channel 52 is provided with a channel wall, and the potting glue cannot enter the independently arranged pressure channel 52, avoiding the potting glue from sealing the pressure channel 52.

[0074] In the application, the oppositely arranged pressure channels 52 on the fixing seat 5 are used to uniformly guide the pressure medium entering from the outside of the finished product shell into the measuring side 13 of the ceramic pressure core 1, and the pressure channel 52 is isolated from the heat-conducting glue and the potting glue protection area, so that the NTC chip 3 and the lead 31 of the NTC chip 3 and its welding point will not directly contact the measured pressure medium. This structure makes the pressure channel 52 clear in direction and has minimum resistance, avoiding the response delay, pressure loss or local extrusion caused by the detour of the pressure path in the traditional structure, and improving the accuracy of pressure measurement.

[0075] Through the double-layer sealing of the NTC area by the heat-conducting glue and the potting glue, the NTC chip 3 is not disturbed by the pressure liquid or gas in terms of temperature collection and electrical connection, so as to realize the independence and non-interference of the temperature and pressure measurement functions.

[0076] Regarding the specific structure of the cooperation and connection of the fixing seat 5, the lead 31 of the NTC chip 3, the lead sleeve 4 and the metal sheath 6, this embodiment is shown inFigures 1 to 5 As shown, a vertically upward-extending positioning post 53 is provided on the center of the axis of the fixing base 5 facing the metal sheath 6. The side wall of the positioning post 53 is provided with oppositely arranged protruding fasteners 531. The side wall of the corresponding protruding fastener 531 of the metal sheath 6 is also provided with a fastening hole 61. A mounting cavity 532 is provided at the axis of the positioning post 53. Two oppositely arranged mounting grooves 533 are provided on the side wall of the positioning post 53. The mounting grooves 533 are connected to the mounting cavity 532. The mounting sleeve 4 is fitted inside the mounting cavity 532. The lead wire 31 of the NTC chip 3 extends out through the mounting groove 533 and enters the potting groove 51. The metal sheath 6 is fitted outside the positioning post 53. The protruding fasteners 531 extend out of the fastening holes 61 corresponding to their positions, forming a snap-fit ​​positioning structure. The snap-fit ​​positioning structure connects and fixes the metal sheath 6 to the fixing base 5, thereby improving the stability of the metal sheath 6 in protecting the NTC chip 3.

[0077] When applied, the positioning post 53, mounting cavity 532, mounting groove 533 on the fixed base 5 and the snap hole 61 of the metal sheath 6 form a multi-point limiting structure, so that a stable mechanical connection is established between the NTC chip 3, the lead sleeve 4 and the metal sheath 6.

[0078] The mounting cavity 532 is used to install the lead sleeve 4, providing axial and radial limiting for the lead sleeve 4; the mounting groove 533 provides an exit path for the lead 31 of the NTC chip 3; the protruding buckle 531 on the positioning post 53 and the buckle hole 61 of the metal sheath 6 form a snap-fit ​​structure, realizing the quick assembly and firm fixation of the metal sheath 6 and the fixing base 5; through this structure, the lead 31 of the NTC chip 3 will not experience swaying or tensile stress due to vibration, operation, or pressure impact during the entire operation of the needle temperature and pressure sensor, ensuring the stability of the temperature signal acquisition path. This structure also simplifies the manufacturing process, reduces assembly difficulty, and helps improve the quality consistency of mass-produced needle temperature and pressure sensors.

[0079] A second implementation of the through-needle temperature and pressure sensor, for example Figure 5 As shown, the difference between this embodiment and the first embodiment is that a wing plate 62 that opens obliquely outward is provided in the vertical direction outside the buckle hole 61 of the metal sheath 6. The wing plate 62 is a structure that is integrally stamped with the outer wall of the metal sheath 6. When the finished shell is installed outside the metal sheath 6, the wing plate contacts the finished shell to form grounding, so as to improve the stability and accuracy of the temperature signal output by the NTC chip 3 through the lead 31.

[0080] In application, the metal sheath 6 has an integrally stamped wing plate 62 outside the buckle hole 61. After the sensor is assembled to the metal casing, the wing plate 62 can automatically and elastically fit against the inner wall of the metal casing, forming a stable grounding point. Through this structure, the static charge on the metal casing can be effectively and quickly discharged, preventing static electricity from affecting the weak temperature signal output by the lead 31 of the NTC chip 3.

[0081] The presence of the flying wing plate 62 can also form a local electromagnetic shielding effect, reducing the interference of surrounding electromagnetic noise on the temperature signal line and improving the accuracy and stability of the temperature signal output. This solution avoids the complicated process of needing to separately weld the grounding wire or set up additional grounding contacts in the traditional solution, making the structure simpler, the cost lower and the reliability higher.

[0082] Based on the above embodiments of the through-needle temperature and pressure sensor, an assembly process for the through-needle temperature and pressure sensor is provided, including the following steps, including the following steps in the order of S1 to S6: S1, insert the NTC chip and leads into the lead sleeve, and install the lead sleeve on the fixing base, so that the leads of the NTC chip are neatly positioned in the fixing base.

[0083] S2. Inject thermally conductive adhesive between the NTC chip and the metal sheath to bond, fix, and buffer the NTC chip.

[0084] S3. Place the metal sheath over the lead sleeve and connect and fix the metal sheath to the fixing base through the snap-fit ​​structure, and then fill with potting compound.

[0085] S4. Mount the mounting base to the ceramic pressure core, arranging one end of the NTC pin and the PIN pin on the ceramic pressure core toward the direction of the circuit board to be installed.

[0086] S5. The leads of the NTC chip are soldered to the other end of the NTC pin on the ceramic pressure core using resistance welding.

[0087] S6. Inject potting compound into the potting tank to cover the solder joints of the NTC chip leads and the space enclosed by the mounting base and the ceramic pressure core, and cure to form a secondary sealing layer to complete the assembly of the through needle temperature and pressure sensor.

[0088] In application, the assembly process of the through-needle temperature and pressure sensor involves sequentially executing steps S1 to S6, which allows the NTC chip for temperature acquisition, the ceramic pressure core for pressure acquisition, and their electrical connection structure to be solidly formed step by step.

[0089] First, by placing the NTC chip's leads inside the lead sleeve in step S1 and then aligning them secondary by the fixing seat, the temperature signal path can be dually limited in both the axial and radial directions before soldering, avoiding problems such as lead twisting, suspension, or force displacement that are common in traditional bare wire structures.

[0090] In addition to forming a continuous heat conduction path, the thermally conductive adhesive injection in step S2, together with the metal sheath and mounting base, forms a buffer coating layer for the NTC chip, ensuring that the chip remains in its correct position and is not damaged even under pressure pulses, vibrations, or drops.

[0091] In step S3, the snap-fit ​​structure of the metal sheath cooperates with the positioning post and protruding block of the fixing seat to form a high-strength mechanical skeleton on the outside of the NTC chip, providing a structural stability basis for subsequent glue injection curing and welding.

[0092] In step S4, the mounting of the fixing base and the ceramic pressure core further forms a unified direction for signal output, aligning the PIN pins and NTC pins in the arrangement, providing a convenient and stable docking method for the assembly of the entire circuit board.

[0093] The resistance welding connection method in step S5, together with the aforementioned measures of neat lead wires and stable structure, ensures that the weld joint is subjected to uniform force and is not affected by the swing of the metal sheath or lead wires, thereby improving the welding quality and avoiding sputtering contamination of the ceramic pressure core.

[0094] Finally, step S6 seals and cures the solder joints and mounting gaps with potting compound, completely isolating the temperature acquisition path from the pressure channel, forming a secondary sealing structure, which significantly improves the sealing reliability, environmental resistance and long-term stability of the whole machine.

[0095] The gradual implementation of the overall process not only avoids problems such as multiple sealing ring failures, loose welds, and structural loosening in traditional solutions, but also achieves a highly reliable, low-complexity manufacturing method for needle temperature and pressure sensors that is suitable for automated mass production through the synergistic optimization of structure and process.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A needle temperature and pressure sensor, characterized in that, Including ceramic pressure cores and NTC components; The ceramic pressure core is equipped with an NTC probe for temperature signal output. The NTC component includes an NTC chip, a lead sleeve, a mounting bracket, and a metal sheath; The NTC chip is located at one end of the lead sleeve, and the leads of the NTC chip are sleeved inside the lead sleeve and extend out of the other end of the lead sleeve in a regular shape. The lead sleeve is installed on the mounting base and the leads of the NTC chip are aligned into the mounting base; The metal sheath is fitted over the lead sleeve and the NTC chip and fixed to the mounting base; The leads of the NTC chip are connected to the end of the NTC probe facing the mounting base by resistance welding, so as to achieve sputter-free welding of the leads and the NTC probe between the mounting base and the ceramic pressure core. The solder joint where the NTC chip leads are soldered to the NTC pins is filled with potting compound. The potting compound is used to encapsulate and cure the solder joint, thereby improving the stability of the solder joint connection and the reliability of conduction. The mounting base has two opposing potting grooves, which cover the leads of the NTC chip extending from the lead sleeve and the metal sheath, as well as the solder joints where the leads of the NTC chip are soldered to the NTC pins. The potting grooves connect the space enclosed by the mounting base and the ceramic pressure core. The potting compound is injected into the potting grooves and the space enclosed by the mounting base and the ceramic pressure core to seal the mounting base and bond the mounting base to the ceramic pressure core. The mounting base has a vertically upward-extending positioning post at the center of its axis facing the metal sheath. The sidewall of the positioning post has opposing protruding fasteners, and the sidewall of the corresponding protruding fastener on the metal sheath also has a fastening hole. A mounting cavity is located at the center of the positioning post, and two opposing mounting grooves are located on the sidewall of the positioning post, communicating with the mounting cavity. The lead sleeve is fitted inside the mounting cavity, and the NTC chip's lead extends through the mounting groove and enters the potting groove. The metal sheath is fitted over the positioning post, and the protruding fasteners extend outside the fastening holes corresponding to their positions, forming a snap-fit ​​positioning structure. This snap-fit ​​positioning structure connects and fixes the metal sheath to the mounting base, improving the stability of the metal sheath in protecting the NTC chip.

2. The needle temperature and pressure sensor according to claim 1, characterized in that, The ceramic pressure core includes either a resistive pressure core or a capacitive pressure core.

3. The needle temperature and pressure sensor according to claim 1, characterized in that, The ceramic pressure core is also provided with a PIN pin for pressure signal output; The other end of both the PIN pin and the NTC pin is used to connect to the circuit board to be installed, and to output pressure signals and temperature signals to the circuit board.

4. The needle temperature and pressure sensor according to claim 1, characterized in that, Thermally conductive adhesive is injected between the NTC chip and the metal sheath to bond the mounting base and the metal sheath, thereby improving temperature measurement sensitivity and providing buffer protection for the NTC chip.

5. The needle temperature and pressure sensor according to claim 4, characterized in that, The mounting base is provided with two opposing pressure channels. Under the sealing protection of the NTC chip, the NTC chip lead and the NTC pin solder joint, the liquid or gas whose pressure needs to be measured is introduced into the finished shell to be installed and then introduced into the measuring side of the ceramic pressure core through the pressure channels.

6. The needle temperature and pressure sensor according to claim 1, characterized in that, The metal sheath has a wing plate that opens obliquely outward in the vertical direction outside the buckle hole. The wing plate is a structure that is integrally stamped with the outer wall of the metal sheath. When the finished housing is installed outside the metal sheath, the flying wing plate contacts the finished housing to form a ground, thereby improving the stability and accuracy of the temperature signal output by the NTC chip via the lead wire.

7. An assembly process for a needle temperature and pressure sensor, comprising the needle temperature and pressure sensor according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Insert the NTC chip and leads into the lead sleeve, and install the lead sleeve on the mounting base so that the NTC chip leads are properly positioned in the mounting base. S2. Inject thermally conductive adhesive between the NTC chip and the metal sheath to bond, fix, and buffer the NTC chip. S3. Place the metal sheath over the lead sleeve and connect and fix the metal sheath to the fixing base through the snap-fit ​​structure, and then fill with potting compound. S4. Mount the mounting base to the ceramic pressure core, arranging one end of the NTC pin and the PIN pin on the ceramic pressure core toward the direction of the circuit board to be installed. S5. The leads of the NTC chip are soldered to the other end of the NTC pin on the ceramic pressure core using resistance welding. S6. Inject potting compound into the potting tank to cover the solder joints of the NTC chip leads and the space enclosed by the mounting base and the ceramic pressure core, and cure to form a secondary sealing layer to complete the assembly of the through needle temperature and pressure sensor.

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