A pressure sensor based on ceramic resistance sensing technology

Abstract

The present invention discloses a pressure sensor based on ceramic resistance sensing technology, comprising a sensor housing, an electrical connector, a sensitive element seat, a PCB circuit board, and a pressure sensitive element. The lower end of the sensor housing is integrally formed with a threaded pipe joint, a sensitive element seat is installed in the inner cavity of the sensor housing, a fluid pipeline inserted into the inner cavity of the threaded pipe joint is integrally provided at the lower end of the sensitive element seat, a square concave cavity is provided on the upper end surface of the sensitive element seat, and the pressure sensitive element is installed in the square concave cavity. The lower end of the electrical connector is placed inside the sensor housing, and three PIN pins are vertically inserted on the inner end surface of the electrical connector. The PCB circuit board is inserted into two groups of symmetrically opened U-shaped grooves on the outer side wall of the lower end of the electrical connector, and three groups of connection holes respectively connected to the lower ends of the three PIN pins are provided on the PCB circuit board. The lower end surface of the PCB circuit board abuts against the top surface of the supporting boss, and the PCB circuit board is connected to the pressure sensitive element through four groups of pin soldering. The present invention can realize high-precision detection and has strong structural stability.

Description

Technical Field

[0001] The invention relates to a pressure sensor technology, in particular to a pressure sensor based on ceramic resistance sensing technology. Background Art

[0002] Pressure sensors are mainly used to collect the pressure of liquid or gas in an inner cavity or pipeline. With the continuous improvement of control technology and control systems, traditional control methods no longer meet the needs of the industry, and the accuracy and adaptability of traditional sensors also need to be further improved. For example, in the automotive air-conditioning industry, traditional automobiles use pressure switches to collect a certain pressure value of the refrigerant in the pipeline to determine the operation or stop of the system. This simple and crude control method is not only inefficient, wastes energy, but also easily damages the system, so it is gradually replaced by pressure sensors. In addition, traditional pressure sensors based on MEMS and ceramic capacitor technology will produce serious drift due to the influence of temperature, especially in high and low temperature conditions, the error increases significantly, and it is impossible to collect high-precision data in the entire temperature range. This patent develops a pressure sensor based on ceramic resistor sensing technology, which can replace traditional pressure switches to achieve precise control, and can also overcome the problem that traditional pressure sensors cannot achieve data collection in the entire temperature range. Summary of the invention

[0003] The object of the present invention is to provide a pressure sensor based on ceramic resistance sensing technology to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A pressure sensor based on ceramic resistance sensing technology comprises a sensor housing, an electrical connector, a sensitive element seat, a PCB circuit board, and a pressure sensitive element. The lower end of the sensor housing is integrally formed with a threaded pipe joint, the sensitive element seat is installed in the inner cavity of the sensor housing, the lower end of the sensitive element seat is integrally provided with a fluid pipeline inserted into the inner cavity of the threaded pipe joint, the inner cavity of the fluid pipeline is communicated with the inner cavity of the threaded pipe joint, the upper end surface of the sensitive element seat is provided with a square cavity, two groups of symmetrically arranged support bosses and two groups of symmetrically arranged buckles, the square cavity is communicated with the inner cavity of the fluid pipeline, the pressure sensitive element is installed in the square cavity, the lower end of the electrical connector is placed inside the sensor housing, three PIN pins are vertically inserted on the inner end surface of the electrical connector, the PCB circuit board is plugged into two groups of symmetrically opened U-shaped grooves on the outer wall of the lower end of the electrical connector, and the PCB circuit board is provided with three groups of U-shaped grooves respectively connected to the three PI A connecting hole connected to the lower end of the N pin, a positioning protrusion for abutting the upper end surface of the PCB circuit board is also provided on the inner end surface of the electrical connector, the lower end surface of the PCB circuit board abuts against the top surface of the supporting boss, and two groups of symmetrical grooves are also provided on the outer wall of the lower end of the electrical connector, the two groups of grooves are respectively engaged with the two groups of buckles, and the PCB circuit board and the pressure sensitive element are connected by soldering through four groups of pins.

[0006] Furthermore, a plug hole matching with the upper end of the PIN pin is provided on the inner end surface of the electrical connector, and the upper end of the PIN pin and the plug hole are connected by interference fit.

[0007] Furthermore, the lower end of the PIN needle is connected to the connecting hole by interference fit.

[0008] Furthermore, the pressure sensitive element is bonded in the square cavity by an adhesive and covers the top of the pipe opening where the fluid pipeline communicates with the square cavity.

[0009] Furthermore, the upper end of the sensor housing is shrunk by a shrunk machine.

[0010] Furthermore, the gap between the necked portion of the upper end of the sensor housing and the outer wall of the electrical connector is filled with sealant.

[0011] Furthermore, a first sealing ring is sleeved on the outside of the fluid pipeline at the lower end of the sensitive element seat.

[0012] Furthermore, a second sealing ring is sleeved outside the threaded pipe joint at the lower end of the sensor housing.

[0013] Furthermore, the pressure sensitive element is made of ceramic resistor.

[0014] Furthermore, the PCB circuit board is provided with positioning circular holes which are matched and connected with the four groups of pins.

[0015] The beneficial effects of the present invention are:

[0016] The present invention provides a pressure sensor based on ceramic resistor sensing technology. By adopting a pressure sensitive element made of ceramic resistor, the detection accuracy of the sensor is improved, the influence of temperature on the accuracy is reduced, and the operating temperature range is expanded. Normal operation within the range of -40°C to 150°C can be achieved. The full temperature range and full range accuracy can be improved to 1.8% VDD. Through the structural design of the present application, the quality stability and working reliability are improved. The PCB circuit board and the pressure sensitive element are independently manufactured and connected by pin soldering, replacing the traditional integrated manufacturing of the circuit board and the sensitive element, reducing the processing difficulty and manufacturing cost, and improving the quality stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0018] Figure 1 It is a split diagram of the present invention.

[0019] Figure 2 It is a cross-sectional view of the present invention.

[0020] Figure 3 It is a three-dimensional view of the electrical connector of the present invention.

[0021] Figure 4 It is a structural diagram of the sensitive element seat of the present invention.

[0022] Figure 5 It is a structural diagram of the pressure sensitive element of the present invention.

[0023] Figure 6 It is a top view of the structure of the PCB circuit board of the present invention.

[0024] In the figure: 1. sensor housing, 2. electrical connector, 3. sensitive element seat, 4. PCB circuit board, 5. pressure sensitive element, 6. threaded pipe joint, 7. fluid pipeline, 8. supporting boss, 9. buckle, 10. PIN needle 10, 11. U-shaped groove, 12. connecting hole, 13. positioning protrusion, 14. groove, 15. pin, 16. plug-in hole, 17. sealant, 18. first sealing ring, 19. second sealing ring, 20. positioning circular hole, 21. adhesive. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1-6As shown, the present invention provides a pressure sensor based on ceramic resistance sensing technology, including a sensor housing 1, an electrical connector 2, a sensitive element seat 3, a PCB circuit board 4, and a pressure sensitive element 5. The lower end of the sensor housing 1 is integrally formed with a threaded pipe joint 6, and the sensor housing 1 is connected to the installation hole on the pipeline or the cavity wall through the threaded pipe joint 6 at its lower end. The sensitive element seat 3 is installed in the inner cavity of the sensor housing 1, and the lower end of the sensitive element seat 3 is integrally provided with a fluid pipeline 7 inserted into the inner cavity of the threaded pipe joint 6. The inner cavity of the fluid pipeline 7 is communicated with the inner cavity of the threaded pipe joint 6. The upper end surface of the sensitive element seat 3 is provided with a square cavity, two groups of symmetrically arranged support bosses 8 and two groups of symmetrically arranged buckles 9, the square cavity is communicated with the inner cavity of the fluid pipeline 7, the pressure sensitive element 5 is installed in the square cavity, and the lower end of the electrical connector 2 is placed on the sensor Inside the shell 1, three PIN needles 10 are vertically inserted on the inner end surface of the electrical connector 2. The three PIN needles 10 are used for pressure output, grounding, and power connection respectively. The PCB circuit board 4 is designed with notches at the four corners for easy insertion into two groups of symmetrically opened U-shaped grooves 11 on the outer wall of the lower end of the electrical connector 2, and the PCB circuit board 4 is provided with three groups of connection holes 12 respectively connected to the lower ends of the three PIN needles 10. A positioning protrusion 13 for abutting against the upper end surface of the PCB circuit board 4 is also provided on the inner end surface of the electrical connector 2. The lower end surface of the PCB circuit board 4 abuts against the top surface of the supporting boss 8. Two groups of symmetrically opened grooves 14 are also provided on the outer wall of the lower end of the electrical connector 2. The two groups of grooves 14 are respectively engaged with the two groups of buckles 9. The PCB circuit board 4 and the pressure sensitive element 5 are soldered and connected through four groups of pins 15.

[0027] In this embodiment, a plug-in hole 16 that cooperates with the upper end of the PIN needle 10 is provided on the inner end surface of the electrical connector 2. The upper end of the PIN needle 10 and the plug-in hole 16 are connected by interference fit. The lower end of the PIN needle 10 is formed by one-time extrusion to make its lower end wider and form a flat shape. After the lower end of the PIN needle 10 is inserted into the connecting hole 12, an interference fit is formed between the connecting hole 12, which replaces the traditional sensor using soft flat cable soldering connection method, improves the reliability of the connection, and reduces the sensor failure caused by the breakage of the soft flat cable during production or use, thereby improving the quality stability and working reliability of the sensor.

[0028] In this embodiment, the pressure sensitive element 5 is bonded in the square cavity by an adhesive 21 and covers the top of the pipe opening where the fluid pipe 7 communicates with the square cavity, ensuring that the fluid entering the threaded pipe joint 6 transmits the pressure to the pressure sensitive element 5 through the fluid pipe 7, so that the pressure sensitive element 5 senses the pressure of the fluid at this time. The pressure sensitive element 5 is made of a ceramic resistor, and the resistance value changes under the action of pressure. The change in resistance value is transmitted to the chip through the circuit in the PCB circuit board 4. The chip calculates and outputs the corresponding result, which is finally amplified and output in the form of analog voltage through the PIN needle 10 for pressure output to an external controller connected to the sensor.

[0029] In this embodiment, the upper end of the sensor housing 1 is shrunk by a shrinking machine to wrap the lower end of the electrical connector 2, and the gap between the shrinkage of the upper end of the sensor housing 1 and the outer wall of the electrical connector 2 is filled with sealant 17 to seal this place to prevent dust and steam from entering.

[0030] In this embodiment, a first sealing ring 18 is sleeved on the outside of the fluid pipeline 7 at the lower end of the sensor seat 3 , and a second sealing ring 19 is sleeved on the outside of the threaded pipe joint 6 at the lower end of the sensor housing 1 .

[0031] In this embodiment, a positioning circular hole 20 is provided on the PCB circuit board 4 for cooperation with the four groups of pins 15, which replaces the traditional sensor's flexible flat cable soldering connection method, improves the reliability of the connection, and reduces sensor failure caused by the breakage of the flexible flat cable during the manufacturing or use process, thereby improving the quality stability and working reliability of the sensor.

[0032] The present invention adopts a pressure sensitive element 5 made of a ceramic resistor to replace the traditional ceramic capacitor sensor element, thereby improving the detection accuracy of the sensor, reducing the influence of temperature on the accuracy, and expanding the operating temperature range, so that normal operation can be achieved within the range of -40°C to 150°C, and the full temperature range and full range accuracy can be improved to 1.8% VDD;

[0033] The PCB circuit board 4 is inserted into two groups of symmetrically opened U-shaped grooves 11 on the outer wall of the lower end of the electrical connector 2, so that the horizontal position of the PCB circuit board 4 is positioned. The lower end surface of the PCB circuit board 4 abuts against the top surface of the supporting boss 9, and the upper end surface of the PCB circuit board 4 abuts against the positioning protrusion 13, so that the PCB circuit board 4 is positioned in the vertical direction, and the structural stability of the PCB circuit board 4 is maintained. The buckle 9 on the upper end surface of the sensitive element seat 3 is engaged with the groove 14 on the outer wall of the lower end of the electrical connector 2, so that the relative rotation between the sensitive element seat 3 and the electrical connector 2 can be prevented to damage the connection between the electronic components;

[0034] The PCB circuit board 4 and the pressure sensitive element 5 are independently manufactured and connected by soldering through the pins 15, replacing the traditional integrated manufacturing of the circuit board and the sensitive element, reducing the processing difficulty and manufacturing cost, and improving the quality stability.

[0035] The embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pressure sensor based on ceramic resistance sensing technology, characterized in that: The sensor housing (1) comprises a sensor housing (1), an electrical connector (2), a sensitive element seat (3), a PCB circuit board (4), and a pressure sensitive element (5). The lower end of the sensor housing (1) is integrally formed with a threaded pipe joint (6). The sensitive element seat (3) is installed in the inner cavity of the sensor housing (1). The lower end of the sensitive element seat (3) is integrally provided with a fluid pipeline (7) inserted into the inner cavity of the threaded pipe joint (6). The inner cavity of the fluid pipeline (7) is communicated with the inner cavity of the threaded pipe joint (6). The upper end surface of the sensitive element seat (3) is provided with a square cavity, two groups of symmetrically arranged supporting bosses (8), and two groups of symmetrically arranged buckles (9). The square cavity is communicated with the inner cavity of the fluid pipeline (7). The pressure sensitive element (5) is installed in the square cavity. The lower end of the electrical connector (2) is placed inside the sensor housing (1). Three PIN pins (10) are vertically inserted on the inner end surface of the electrical connector (2). The PCB circuit board (4) is plugged into two groups of symmetrically arranged U-shaped pins (10) on the outer wall of the lower end of the electrical connector (2). The electrical connector (2) is provided with a plurality of symmetrical grooves (14), and the PCB circuit board (4) is provided with three groups of connection holes (12) respectively connected to the lower ends of the three PIN pins (10). The lower ends of the PIN pins 10 are widened to form a flat shape. After the lower ends of the PIN pins (10) are inserted into the connection holes (12), an interference fit is formed between the connection holes (12). The inner end surface of the electrical connector (2) is also provided with a positioning protrusion (13) for abutting against the upper end surface of the PCB circuit board (4). The lower end surface of the PCB circuit board (4) abuts against the top surface of the supporting boss (8). The outer wall of the lower end of the electrical connector (2) is also provided with two groups of symmetrical grooves (14). The two groups of grooves (14) are respectively engaged with the two groups of buckles (9). The PCB circuit board (4) and the pressure sensitive element (5) are soldered and connected through four groups of pins (15).

2. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: An inserting hole (16) that matches with the upper end of the PIN needle (10) is provided on the inner end surface of the electrical connector (2), and the upper end of the PIN needle (10) is connected to the inserting hole (16) by interference fit.

3. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: The lower end of the PIN needle (10) is connected to the connecting hole (12) by interference fit.

4. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: The pressure sensitive element (5) is bonded in the square cavity by means of an adhesive (21) and covers the top of the pipe opening of the fluid pipeline (7) communicating with the square cavity.

5. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: The upper end of the sensor housing (1) is shrunk by a shrunk machine.

6. The pressure sensor based on ceramic resistance sensing technology according to claim 5, characterized in that: The gap between the shrinkage at the upper end of the sensor housing (1) and the outer wall of the electrical connector (2) is filled with sealing glue (17).

7. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: A first sealing ring (18) is sleeved on the outside of the fluid pipeline (7) at the lower end of the sensitive element seat (3).

8. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: A second sealing ring (19) is sleeved on the outside of the threaded pipe joint (6) at the lower end of the sensor housing (1).

9. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: The pressure sensitive element (5) is made of a ceramic resistor.

10. The pressure sensor based on ceramic resistance sensing technology according to claim 1, characterized in that: The PCB circuit board (4) is provided with positioning circular holes (20) that are cooperatively connected to the four groups of pins (15).

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