Temperature pressure sensor and manufacturing method thereof

Abstract

The invention discloses a temperature and pressure sensor and a manufacturing method thereof, the temperature and pressure sensor comprises a support assembly formed by an inner support and a thermistor through an injection molding process, two pin copper wires of the thermistor are welded to an insertion piece of the inner support, and a plastic supporting structure wrapping the thermistor and the inner support is formed through injection molding; one end of a PIN needle of the terminal button is connected with an external plugging port; one end of a conductive circuit of the flexible wire board is respectively welded with the PIN of the ceramic capacitor and the insertion piece of the inner bracket, and the other end of the conductive circuit of the flexible wire board is welded with the other end of the PIN of the terminal button; a through hole is formed between the support assembly and the shell, a medium makes contact with the ceramic capacitor through the through hole, the ceramic capacitor transmits a pressure signal to the outside through the flexible wire board and the end button, the thermistor senses the temperature of the medium through the plastic supporting structure, and a temperature signal is transmitted to the outside through the inserting piece, the flexible wire board and the end button. The thermistor is effectively prevented from losing efficacy due to medium impact, and meanwhile, the structural process is relatively simple and easy to assemble.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensor. More particularly, the present application relates to a temperature and pressure sensor and a manufacturing method thereof. BACKGROUND

[0002] Sensor technology is one of the important technologies of modern measurement and automation systems, from the process control of production to the modern scientific and technological life, almost every technology cannot do without sensor. Temperature and pressure sensor can be said to be the two most widely used sensors in the sensor industry, often need to be used together, especially in some places need to measure temperature and pressure in many places, the use of temperature and pressure sensor alone will make the system more complex, and the cost is also higher. The temperature and pressure sensor solves this problem very well, especially in limited space, the temperature and pressure sensor shows its unique charm. As a new type of sensor, the temperature and pressure sensor meets the needs of development, not only can better meet the needs of customers, but also is a breakthrough of sensor industry, a new research hotspot.

[0003] At present, there are two ways to sense temperature: one is that the temperature sensing element thermistor is exposed and directly contacts with the medium, which may cause short circuit between the metal impurities in the medium and the exposed feet of the thermistor, and the thermistor may be impacted by the medium, which may cause product failure; the other is that the temperature sensing element thermistor is sleeved with a metal protection tube, the metal protection tube needs to be welded and sealed with the shell, and the medium temperature sensing is transmitted through the metal protection tube, the filled heat-conducting material and the NTC thermistor, which has complex structure and high manufacturing cost. SUMMARY

[0004] The purpose of the present application is to provide a temperature and pressure sensor and a manufacturing method thereof, the two feet copper wires of the temperature sensing element thermistor are welded to the inner support insert piece, then the inner support with the welded thermistor is injected with plastic material to form a support assembly, the medium temperature sensing is transmitted through the plastic of the support assembly and the thermistor, the thermistor is completely isolated from the medium, which effectively avoids the impact of the medium on the thermistor, which may cause product failure, and the metal protection sleeve is cancelled, and there is no filled heat-conducting material, so the structure is relatively simple and easy to assemble.

[0005] The technical scheme adopted by the present application to solve the technical problem is to provide a temperature and pressure sensor, comprising: a shell, one end of the shell is open, the other end is provided with threads, and a first sealing ring is arranged outside the threads; a support assembly is arranged in the shell and is integrally formed by an inner support and a thermistor through an injection molding process, two feet copper wires of the thermistor are welded to the insert piece of the inner support, and a plastic support structure wrapping the thermistor and the inner support is formed by injection molding; A ceramic capacitor is arranged in the support assembly as a pressure sensing element; An end button is supported and fixed by the support assembly, and one end of a PIN needle of the end button is connected to an external plug interface; A flexible soft wire board is internally provided with a conductive circuit, one end of the conductive circuit is respectively welded and connected to the PIN needle of the ceramic capacitor and the tab of the inner support, and the other end is welded and connected to the other end of the PIN needle of the end button; The support assembly and the shell are provided with a through hole for the medium to enter, the medium contacts the ceramic capacitor through the through hole, the ceramic capacitor transmits the pressure signal to the outside through the flexible soft wire board and the end button, and the thermistor transmits the temperature signal to the outside through the tab of the inner support, the flexible soft wire board and the end button in sequence after sensing the temperature of the medium through the plastic support structure.

[0006] Preferably, the temperature and pressure sensor, a second sealing ring is arranged between the support assembly and the ceramic capacitor, and a third sealing ring is arranged between the support assembly and the shell, and the second sealing ring and the third sealing ring are O-rings of the same specification; The end button and the shell are filled with RTV silicone.

[0007] Preferably, the temperature and pressure sensor, one side of the flexible soft wire board is provided with an asymmetric cutting seam, and the tail end of the cutting seam is provided with a circular through hole.

[0008] Preferably, the temperature and pressure sensor, the support assembly is provided with a buckle groove, and the end button is clamped with the support assembly through the buckle groove.

[0009] Preferably, the temperature and pressure sensor, the support assembly is provided with an anti-reverse column, and the cross-sectional shape of the anti-reverse column matches the anti-reverse notch of the ceramic capacitor.

[0010] Preferably, the temperature and pressure sensor, the conductive circuit of the flexible soft wire board is provided with three types of pad holes: The ceramic PIN needle pad hole is welded and connected to the PIN needle of the ceramic capacitor; The support assembly tab pad hole is welded and connected to the tab of the inner support; The end button pad hole is welded and connected to the PIN needle of the end button.

[0011] Preferably, the temperature and pressure sensor, the support assembly is internally provided with two air inlet holes distributed on opposite sides, and an air inlet groove is arranged directly below the air inlet holes, the air inlet groove is recessed inward along the thickness direction of the support assembly, and the cross section is arc-shaped.

[0012] Preferably, the temperature and pressure sensor, the head of the support assembly is subjected to glue reduction treatment.

[0013] The application also provides a method for manufacturing the temperature and pressure sensor support assembly, the injection molding process is secondary injection molding, and the method comprises the following steps: S1: pre-preparing an inner support, a head of the inner support is provided with a thermistor placing groove and a pin spacing groove; S2: welding two copper pins of the thermistor to the insertion piece of the inner support; S3: placing the welded inner support into a mold as an insert, injecting plastic material to cover the thermistor and the inner support, and forming an integrated structure.

[0014] Preferably, in the method, the pin spacing groove of the inner support is located between the two copper pins of the thermistor, and a non-pin area of the thermistor is completely wrapped by the plastic support structure of the support assembly.

[0015] The application at least has the following beneficial effects: the two copper pins of the temperature sensing element thermistor are welded to the insertion piece of the inner support, then the inner support with the welded thermistor is injection molded with plastic material to form the support assembly, medium temperature sensing is transmitted through the plastic of the support assembly and the thermistor, the thermistor is completely isolated from the medium, and the thermistor is effectively prevented from being impacted by the medium, which may cause product failure, meanwhile, the metal protective sleeve is cancelled, and no filling heat-conducting material is used, so that the structure process is relatively simple and easy to assemble.

[0016] Other advantages, objects and features of the application will be apparent from the following description, and will be understood by those skilled in the art through reading the application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a perspective view of a temperature and pressure sensor according to the application; Figure 2 FIG. 2 is a sectional view of the structure of the temperature and pressure sensor according to the application; Figure 3 FIG. 3 is a structural view of a flexible soft wire plate in the temperature and pressure sensor according to the application; Figure 4 FIG. 4 is a perspective view of a support assembly in the temperature and pressure sensor according to the application; Figure 5 FIG. 5 is an exploded view of the support assembly in the temperature and pressure sensor according to the application; Figure 6 FIG. 6 is a structural view of an end knob in the temperature and pressure sensor according to the application; Figure 7 FIG. 7 is a structural view of a ceramic capacitor in the temperature and pressure sensor according to the application; Explanation of reference signs: 1, housing, 11, thread, 12, first sealing ring, 2, support assembly, 21, inner support, 211, hot wire placement slot, 212, pin spacer slot, 213, insertion piece, 22, hot wire, 23, plastic support structure, 24, buckle slot, 25, anti-reverse column, 26, air inlet hole, 27, air inlet groove, 28, head, 3, ceramic capacitor, 31, PIN of ceramic capacitor, 32, symmetrical notch, 33, anti-reverse notch, 4, end button, 41, PIN of end button, 5, flexible soft wire plate, 51, cutting seam, 52, ceramic PIN pad hole, 53, support assembly insertion piece pad hole, 54, end button pad hole, 6, second sealing ring, 7, third sealing ring, 8, RTV silicone. DETAILED DESCRIPTION

[0018] The present application will be described in detail below with reference to the drawings. Those skilled in the art will be able to implement the present application based on these descriptions. Before the present application is described in detail with reference to the drawings, it should be specifically pointed out that the technical solutions and technical features provided in each part of the present application, including the following description, can be combined with each other without conflict.

[0019] In addition, the embodiments of the present application involved in the following description are generally only a part of the embodiments of the present application, not all the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor should belong to the scope of protection of the present application.

[0020] The present application will be described in detail below with reference to the drawings. Those skilled in the art will be able to implement the present application based on these descriptions. Before the present application is described in detail with reference to the drawings, it should be specifically pointed out that the technical solutions and technical features provided in each part of the present application, including the following description, can be combined with each other without conflict. As Figures 1-7 shown, the present application provides a temperature and pressure sensor, comprising: A housing 1, one end of which is open and the other end of which is provided with a thread 11, the sensor is connected to the measuring pipeline through the thread 11, and a first sealing ring 12 is arranged outside the thread 11, which is used to seal and prevent leakage of the medium in the measuring pipeline; A support assembly 2 is arranged in the housing 1 and is integrally formed by an inner support 21 and a hot wire 22 through an injection molding process, both copper wires of the hot wire 22 are welded to the insertion piece 213 of the inner support 21, and a plastic support structure 23 is formed by injection molding to wrap the hot wire 22 and the inner support 21; this plastic support structure 23 must have insulation and sealing properties to completely isolate the hot wire 22 from the outside world.

[0021] A ceramic capacitor 3 is arranged in the support assembly 2 as a pressure sensing element; in this embodiment, an internal cavity is formed between the plastic support structure 23 and the inner support 21, and the ceramic capacitor 3 is arranged in the internal cavity.

[0022] An end knob 4 is supported and fixed by the support assembly 2, and a PIN needle 41 of the end knob is connected to an external plug interface for transmitting signals to an external device. A flexible soft wire plate 5 is internally provided with a conductive circuit, one end of the conductive circuit is welded to the PIN needle 31 of the ceramic capacitor and the tab 213 of the inner support 21, and the other end is welded to the other end of the PIN needle 41 of the end knob; signals enter from one end of the conductive circuit of the flexible soft wire plate 5 through the PIN needle 31 of the ceramic capacitor and the tab 213 of the inner support 21, are transmitted to the other end through the conductive circuit, and are transmitted to the external device through the PIN needle 41 of the end knob.

[0023] A through hole is arranged between the support assembly 2 and the shell 1 for the medium to enter, the medium contacts the ceramic capacitor 3 through the through hole, the ceramic capacitor 3 transmits the pressure signal to the outside through the flexible soft wire plate 5 and the end knob 4, and the temperature signal is transmitted to the outside in sequence through the tab 213 of the inner support 21, the flexible soft wire plate 5 and the end knob 4 after the thermistor 22 senses the temperature of the medium through the plastic support structure 23.

[0024] Further, the temperature and pressure sensor, a second sealing ring 6 is arranged between the support assembly 2 and the ceramic capacitor 3, and a third sealing ring 7 is arranged between the support assembly 2 and the shell 1, the second sealing ring 6 and the third sealing ring 7 are O-rings of the same specification, the support assembly 2 is sealingly connected with the ceramic capacitor 3 and the shell 1 through the second sealing ring 6 and the third sealing ring 7, respectively, effectively improving the waterproof and dustproof performance of the sensor.

[0025] The end knob 4 and the shell 1 are filled with RTV silicone 8, which can better prevent external water vapor and dust from entering the inside of the sensor, and improve the reliability and stability of the sensor.

[0026] Further, the temperature and pressure sensor, the flexible soft wire plate 5 is provided with an asymmetric cutting seam 51 on one side, and the tail end of the cutting seam 51 is provided with a circular through hole, which has a certain stretching space and is convenient for installation, and also avoids damage to the soft plate and welding stress.

[0027] Further, the temperature and pressure sensor, the support assembly 2 is provided with a buckle groove 24, and the end knob 4 is clamped with the support assembly 2 through the buckle groove 24.

[0028] Further, the temperature pressure sensor is provided with an anti-reverse column 25 on the support assembly 2, the cross-sectional shape of the anti-reverse column 25 matches the anti-reverse notch 33 of the ceramic capacitor 3, the anti-reverse column 25 is used for limiting the installation direction of the ceramic capacitor 3, and reverse assembly is prevented.

[0029] Further, the temperature pressure sensor is provided with three types of pad holes on the conductive circuit of the flexible soft wire plate 5: The ceramic PIN needle pad hole 52 is welded with the PIN needle 31 of the ceramic capacitor and is used for transmitting a pressure signal. The support assembly plug-in pad hole 53 is welded with the plug-in piece 213 of the inner support and is used for transmitting a temperature signal. The end knob pad hole 54 is welded with the PIN needle 41 of the end knob and is used for transmitting the pressure signal and the temperature signal to an external device.

[0030] Further, the temperature pressure sensor is provided with two air inlet holes 26 distributed on opposite sides in the inside of the support assembly 2, an air inlet groove 27 is arranged at a position directly below the air inlet hole 26, the air inlet groove 27 is recessed inward along the thickness direction of the support assembly 2, the cross section of the air inlet groove 27 is in an arc shape, the air inlet groove 27 can avoid the air inlet hole 26 being blocked. Medium contacts the ceramic capacitor 3 through the air inlet hole 26 and the air inlet groove 27, and the ceramic capacitor 3 transmits a pressure signal to the outside through the flexible soft wire plate 5 and the end knob 4.

[0031] Further, the temperature pressure sensor is provided with a head 28 of the support assembly 2 which is subjected to glue reduction treatment, so that the temperature response time of the product is ensured.

[0032] The application further provides a method for manufacturing the support assembly of the temperature pressure sensor, the injection molding process is secondary injection molding, and the method comprises the following steps: S1: pre-preparing an inner support 21, a head of the inner support 21 is provided with a thermistor placing groove 211 and a pin spacer groove 212; the thermistor placing groove 211 covers a head of a thermistor 22, effectively reduces impact deformation during injection molding, and causes the phenomenon of the head of the thermistor 22 leaking out.

[0033] S2: welding two copper wires of the thermistor 22 to plug-in pieces 213 of the inner support 21; S3: placing the welded inner support 21 as an insert into a mold, injecting plastic material to cover the thermistor 22 and the inner support 21, and forming an integrated structure. In the embodiment, the plastic material is the same as the injection molding material of the pre-prepared inner support 21.

[0034] Further, the method, the pin spacer groove 212 of the inner support 21 is located between the two pin copper wires of the thermistor 22, the non-pin area of the thermistor 22 is completely wrapped by the plastic support structure 23 of the support assembly 2, the pin is spacered and insulated, the impact deformation during injection molding and the short circuit between the two pins are effectively reduced.

[0035] While the embodiments of the application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, it can be fully applied to various fields suitable for the application, and additional modifications can be easily realized by those skilled in the art, therefore, the application is not limited to specific details and the embodiments shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A temperature and pressure sensor, characterized in that: include: A housing, one end of the housing being open and the other end being provided with a thread, and a first sealing ring being provided on the outer side of the thread; The bracket assembly is disposed within the housing and is formed integrally with the inner bracket and the thermistor through an injection molding process. The two copper wires of the thermistor are welded to the insert of the inner bracket, and a plastic support structure that wraps the thermistor and the inner bracket is formed by injection molding. A ceramic capacitor, as a pressure-sensitive element, is disposed in the bracket assembly; The terminal button is supported and fixed by the bracket assembly, and one end of the PIN pin of the terminal button is connected to the external plug interface; A flexible circuit board having a conductive circuit therein, one end of the conductive circuit being welded to the PIN pin of the ceramic capacitor and the insert of the inner bracket, and the other end being welded to the other end of the PIN pin of the terminal; A through hole is provided between the bracket assembly and the shell for medium to enter. The medium contacts the ceramic capacitor through the through hole. The ceramic capacitor transmits the pressure signal to the outside through the flexible wire board and the terminal button. After the thermistor senses the medium temperature through the plastic support structure, the temperature signal is transmitted to the outside in sequence through the plug of the inner bracket, the flexible wire board and the terminal button.

2. The temperature and pressure sensor according to claim 1, characterized in that: A second sealing ring is provided between the bracket assembly and the ceramic capacitor, and a third sealing ring is provided between the bracket assembly and the housing. The second sealing ring and the third sealing ring are O-rings of the same specifications; The space between the terminal button and the shell is filled with RTV silicone.

3. The temperature and pressure sensor according to claim 1, characterized in that: An asymmetrical cutting slit is provided on one side of the flexible circuit board, and a circular through hole is provided at the tail end of the cutting slit.

4. The temperature and pressure sensor according to claim 1, characterized in that: The bracket assembly is provided with a snap groove, and the terminal button is snap-connected with the bracket assembly through the snap groove.

5. The temperature and pressure sensor according to claim 1, characterized in that: The bracket assembly is provided with an anti-reverse column, and the cross-sectional shape of the anti-reverse column matches the anti-reverse notch of the ceramic capacitor.

6. The temperature and pressure sensor according to claim 1, characterized in that: The conductive circuit of the flexible circuit board is provided with three types of pad holes: Ceramic PIN pin pad hole, soldered to the PIN pin of the ceramic capacitor; The bracket assembly insert pad hole is welded to the insert of the inner bracket; The terminal pad hole is connected to the PIN pin of the terminal by welding.

7. The temperature and pressure sensor according to claim 1, characterized in that: The bracket assembly is provided with two air inlet holes distributed on opposite sides, and an air inlet groove is provided directly below the air inlet holes. The air inlet groove is concave inward along the thickness direction of the bracket assembly, and its cross section is arc-shaped.

8. The temperature and pressure sensor according to claim 1, characterized in that: The head of the bracket assembly is subjected to a glue reduction treatment.

9. A method for manufacturing the temperature and pressure sensor bracket assembly according to claim 1, characterized in that: The injection molding process is a two-shot injection molding process, comprising the following steps: S1: prefabricated inner bracket, with a thermistor placement slot and a pin spacing slot at its head; S2: Solder the two copper wires of the thermistor to the inserts of the inner bracket; S3: Place the welded inner bracket into the mold as an insert, and inject plastic material to cover the thermistor and the inner bracket to form an integrated structure.

10. The method according to claim 9, characterized in that The pin spacing groove of the inner bracket is located between the two copper wires of the thermistor, and the non-pin area of ​​the thermistor is completely wrapped by the plastic support structure of the bracket assembly.

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