Pressure sensor

Abstract

The utility model provides a pressure sensor, and belongs to the technical field of pressure sensors. The problem that an existing pressure sensor is low in sensitivity is solved. The pressure sensor comprises an upper shell and a lower shell connected with the upper shell, an ejector rod is arranged in the lower shell, the upper end of the ejector rod extends into the upper shell, a magnet is arranged at the upper end of the ejector rod, a Hall sensor is arranged in the upper shell in the moving direction of the ejector rod, and a gap with a changeable distance is formed between the Hall sensor and the magnet. A pressure sensor nut is arranged at the upper end in the lower shell, a spring is arranged in the lower shell, the upper end of the spring abuts against the pressure sensor nut, and the lower end of the spring abuts against the ejector rod. According to the structure, the magnet and the Hall sensor are both located in the upper shell, the Hall sensor is not wrapped by other objects, the Hall sensor can sense the magnetic field change more sensitively, and then the sensitivity can be improved.

Description

Technical Field

[0001] This invention belongs to the field of pressure sensor technology, specifically a pressure sensor. Background Technology

[0002] A pressure sensor is a device or apparatus that can sense pressure signals and convert them into usable electrical output signals according to certain rules. The working principle of existing high-pressure water pressure sensors is mainly based on the fact that the measured water pressure acts directly on the diaphragm of the sensor, causing the diaphragm to produce a micro-displacement proportional to the water pressure. This micro-displacement causes a change in the resistance value of the sensor, and the electronic circuitry can detect this change and convert it into a standard measurement signal corresponding to the pressure.

[0003] Currently, a pressure sensor [Authorization Announcement No.: CN202770580U] is disclosed on the China Patent Network, including a circuit board mounting base and a spring mounting base. The circuit board mounting base contains a circuit board and a Hall sensor, and the circuit board and the Hall sensor are fixedly connected. The spring mounting base contains a compression spring, a magnet seat, and a magnet. The magnet seat has a magnet embedded in it, and the compression spring is on the outside of the magnet seat. The circuit board mounting base and the spring mounting base are threaded together, and the spring mounting base is screwed into the circuit board mounting base.

[0004] The pressure sensor described above has the following drawbacks: the Hall sensor and the magnet are isolated by a housing, which is generally made of metal. The metal housing affects the change of the magnetic field, which in turn affects the sensitivity of the Hall sensor, resulting in a decrease in the accuracy of pressure detection. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a pressure sensor. The technical problem this invention aims to solve is: how to address the low sensitivity of existing pressure sensors.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A pressure sensor includes an upper housing and a lower housing connected to the upper housing. The lower housing contains a push rod, the upper end of which extends into the upper housing. A magnet is disposed at the upper end of the push rod. A Hall sensor is disposed within the upper housing in the direction of movement of the push rod, with a variable gap formed between the Hall sensor and the magnet. A pressure sensor nut is disposed at the upper end of the lower housing. A spring is disposed within the lower housing, with its upper end abutting against the pressure sensor nut and its lower end abutting against the push rod.

[0008] Working principle: The pressure sensor detects the water pressure inside the high-pressure pump. As the water pressure increases, it pushes a push rod to move. The push rod overcomes the spring force, causing the magnet to approach the Hall sensor, which then detects the change in water pressure. In this structure, both the magnet and the Hall sensor are located inside the upper housing. The Hall sensor is not enclosed by other objects, making it more sensitive to changes in the magnetic field and thus improving its overall sensitivity.

[0009] In one type of pressure sensor described above, the lower end of the lower housing is provided with a pin that can slide along the axial direction of the push rod, and the upper end of the pin abuts against the lower end of the push rod. In this structure, high-pressure water acts on the pin and pushes the push rod to rotate. The pin and push rod can be integrally formed or have a separate structure.

[0010] In the aforementioned pressure sensor, the lower end of the lower housing has a mounting hole, and the ejector pin passes through the mounting hole. A sealing ring is fitted onto the ejector pin within the mounting hole. The sealing ring serves to waterproof the sensor and prevent water from entering the lower housing.

[0011] In one type of pressure sensor described above, a magnet holder is screwed to the upper end of the push rod, and a magnet is installed inside the upper end of the magnet holder. The magnet is mounted on the magnet holder, which is screwed to the upper end of the push rod. The position of the magnet holder can be adjusted by rotating it, thereby adjusting the distance between the magnet and the Hall sensor. When the spring becomes fatigued, the error of the spring can be compensated by adjusting the position of the magnet.

[0012] In the aforementioned pressure sensor, an adjusting nut is screwed to the upper end of the push rod. The adjusting nut is located below the magnet holder, and its upper surface abuts against the lower surface of the magnet holder. Once the magnet holder is in position, the adjusting nut is rotated, causing its upper surface to press firmly against the lower surface of the magnet holder, thereby locking the magnet holder and preventing it from loosening. This ensures the magnet remains stationary in its position, thus guaranteeing adjustment accuracy.

[0013] In the aforementioned pressure sensor, a second sealing ring is provided between the outer peripheral surface of the pressure sensor nut and the outer peripheral surface of the upper end of the lower housing. The second sealing ring is used to seal the gap between the outer peripheral surface of the pressure sensor nut and the outer peripheral surface of the upper end of the lower housing, preventing water from entering the upper housing and damaging the PCB board and Hall sensor.

[0014] In one of the pressure sensors described above, a through hole is provided on the upper end face of the pressure sensor nut, through which the push rod passes. A sealing ring three is installed inside the through hole. The sealing ring two is used to seal the gap between the outer circumferential surface of the push rod and the wall of the through hole, preventing water from entering the upper housing and damaging the PCB board and Hall sensor.

[0015] In one type of pressure sensor described above, the outer circumferential surface of the lower end of the push rod has an annular limiting boss. The lower end of the spring abuts against the limiting boss, and a washer is provided inside the upper end of the pressure sensor nut. The upper end of the spring abuts against the washer. The washer prevents the sealing ring from easily falling off.

[0016] In the aforementioned pressure sensor, a drain hole is provided on the lower housing, and the drain hole is connected to the chamber where the spring is located. When a small amount of water enters the chamber where the spring is located, a small amount of water will flow out from the drain hole, which also serves to release air and balance the internal and external pressures within the chamber where the spring is located, allowing the push rod to move up and down without obstruction.

[0017] In the aforementioned pressure sensor, a PCB board is disposed within the upper housing, and the Hall sensor is mounted on the PCB board. A mounting protrusion is located at the upper end of the upper housing, and the PCB board is fixed to the mounting protrusion with screws. A signal line is located on the PCB board, extending outside the upper housing. The signal line is used to output a pressure signal, which is then converted and ultimately reflects the pressure numerically.

[0018] Compared with existing technologies, the pressure sensor of this invention has the following advantages: This structure eliminates the diaphragm design, replacing it with a pin that drives the push rod. The pin has high structural strength, is not easily deformed by pressure feedback, and has a long service life. After prolonged use, if the spring fatigues, only the spring needs to be replaced. Furthermore, the pin diameter is relatively small, and the contact area between the pin and the push rod is also small, allowing for a smaller outer diameter of the lower housing, significantly reducing its volume. The upper housing is adapted to the lower housing, also reducing its volume, thus greatly minimizing the overall size of the pressure sensor and lowering manufacturing costs. In addition, the magnet and Hall sensor are both located inside the upper housing, and the Hall sensor is not enclosed by other objects, making it more sensitive to changes in the magnetic field, thereby improving sensitivity. Attached Figure Description

[0019] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0020] In the diagram, 1. Upper housing; 2. Lower housing; 20. Mounting hole; 21. Drain hole; 3. PCB board; 4. Hall sensor; 5. Pressure sensor nut; 50. Through hole; 6. Push rod; 60. Limiting boss; 7. Magnet; 8. Spring; 9. Push pin; 10. Sealing ring one; 11. Magnet holder; 12. Adjusting nut; 13. Sealing ring two; 14. Sealing ring three; 15. Gasket; 16. Mounting protrusion; 17. Signal line; 18. Screw. Detailed Implementation

[0021] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0022] like Figure 1 As shown, this pressure sensor includes an upper housing 1 and a lower housing 2 connected to the upper housing 1. A PCB board 3 is installed inside the upper housing 1, and the PCB board 3 has a Hall sensor 4. A pressure sensor nut 5 is installed at the upper end of the lower housing 2. A push rod 6 is installed inside the lower housing 2, with its upper end extending into the upper housing 1. A magnet 7 is installed at the upper end of the push rod 6, located directly below the Hall sensor 4, i.e., the Hall sensor 4 is located in the direction of movement of the magnet 7. A spring 8 is installed inside the lower housing 2, with its upper end abutting against the pressure sensor nut 5 and its lower end abutting against the push rod 6. A pin 9, which can slide along the axial direction of the push rod 6, is installed at the lower end of the lower housing 2, with its upper end abutting against the lower end of the push rod 6. The pressure sensor is used to detect the water pressure in the high-pressure pump. When the water pressure increases, it pushes the pin 9 to move, which in turn pushes the push rod 6 to move. After the push rod 6 moves against the force of the spring 8, it brings the magnet 7 closer to the Hall sensor 4, thus enabling the Hall sensor 4 to detect the change in water pressure. This structure eliminates the diaphragm design, replacing it with a push pin 9 to drive the push rod 6. The push pin 9 has high structural strength, is not easily deformed by pressure feedback, and has a long service life. After long-term use, if the spring 8 becomes fatigued, only the spring 8 needs to be replaced. Furthermore, the diameter of the push pin 9 is relatively small, and the contact area between the push pin 9 and the push rod 6 is also small. Therefore, the outer diameter of the lower housing 2 can be designed to be smaller, significantly reducing the volume of the lower housing 2. The upper housing 1 is adapted to the lower housing 2, and its volume is also reduced. This, in turn, greatly reduces the overall size of the pressure sensor, lowering manufacturing costs. In addition, the magnet 7 and the Hall sensor 4 in this structure are both located inside the upper housing 1. The Hall sensor 4 is not covered by other objects, making it more sensitive to changes in the magnetic field, thus improving sensitivity.

[0023] like Figure 1As shown, a magnet holder 11 is screwed to the upper end of the push rod 6. A magnet 7 is installed inside the upper end of the magnet holder 11. The magnet 7 is mounted on the magnet holder 11, which is screwed to the upper end of the push rod 6. The position of the magnet holder 11 can be adjusted by rotating it, thereby adjusting the distance between the magnet 7 and the Hall sensor 4. When the spring 8 becomes fatigued, the error of the spring 8 can be compensated by adjusting the position of the magnet 7. An adjusting nut 12 is screwed to the upper end of the push rod 6. The adjusting nut 12 is located below the magnet holder 7, and its upper end face is pressed against the lower end face of the magnet holder 7. After the position of the magnet holder 11 is adjusted to the correct position, the adjusting nut 12 is rotated so that its upper end face is pressed against the lower end face of the magnet holder 11, thereby locking the magnet holder 11 and preventing it from loosening. This ensures that the magnet 7 remains in the correct position, thus ensuring adjustment accuracy.

[0024] like Figure 1 As shown, the outer circumferential surface of the lower end of the push rod 6 has an annular limiting boss 60, the lower end of the spring 8 abuts against the limiting boss 60, and a washer 15 is provided inside the upper end of the pressure sensor nut 5, with the upper end of the spring 8 abutting against the washer 15.

[0025] like Figure 1 As shown, the lower housing 2 has a mounting hole 20 at its lower end. A push pin 9 passes through the mounting hole 20, and a sealing ring 10 is fitted onto the push pin 9 within the mounting hole 20. A sealing ring 13 is provided between the outer circumferential surface of the pressure sensor nut 5 and the outer circumferential surface of the upper end of the lower housing 2. A through hole 50 is provided on the upper end face of the pressure sensor nut 5, through which a push rod 6 passes. A sealing ring 14 is provided within the through hole 50. The sealing rings 10, 13, and 14 prevent water from entering the upper housing 1 and damaging the PCB board 3 and the Hall sensor 4.

[0026] like Figure 1 As shown, a drain hole 21 is provided on the lower housing 2, and the drain hole 21 is connected to the chamber where the spring 8 is located. When a small amount of water enters the chamber where the spring 8 is located, a small amount of water will flow out from the drain hole 21, which also serves to vent air and balance the internal and external pressures of the chamber where the spring 8 is located, so that the push rod 6 can move up and down without obstruction.

[0027] like Figure 1 As shown, the upper end of the upper housing 1 has a mounting protrusion 16, and the PCB board 3 is fixed to the mounting protrusion 16 by screws 18. The PCB board 3 has a signal line 17, which extends out of the upper housing 1.

[0028] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A pressure sensor comprising an upper housing (1) and a lower housing (2) connected to the upper housing (1), characterized in that, The lower shell (2) is provided with a top rod (6), the upper end of the top rod (6) extends into the upper shell (1), the upper end of the top rod (6) is provided with a magnet (7), the upper shell (1) is provided with a Hall sensor (4) in the moving direction of the top rod (6), the Hall sensor (4) and the magnet (7) form a gap with variable distance, the upper end of the lower shell (2) is provided with a pressure sensor nut (5), the lower shell (2) is provided with a spring (8), the upper end of the spring (8) abuts on the pressure sensor nut (5), and the lower end abuts on the top rod (6).

2. A pressure sensor according to claim 1, wherein The lower end of the lower shell (2) is provided with a top pin (9) which can slide along the axial direction of the top rod (6), and the upper end of the top pin (9) abuts against the lower end of the top rod (6).

3. A pressure sensor according to claim 2, wherein The top pin (9) is integrally formed with the top rod (6).

4. A pressure sensor according to claim 2, wherein The lower end of the lower shell (2) is provided with a mounting hole (20), the top pin (9) is arranged in the mounting hole (20), and a sealing ring I (10) is arranged on the top pin (9) in the mounting hole (20).

5. The pressure sensor of claim 1, wherein, The upper end of the top rod (6) is screwed with a magnet holder (11), and the magnet (7) is mounted in the upper end of the magnet holder (11).

6. A pressure sensor according to claim 5, wherein, The upper end of the top rod (6) is screwed with an adjusting nut (12), the adjusting nut (12) is located below the magnet holder (11), and the upper end surface of the adjusting nut (12) abuts against the lower end surface of the magnet holder (11).

7. The pressure sensor of claim 1, wherein, The outer peripheral surface of the lower end of the top rod (6) is provided with a limiting boss (60) in the form of a ring, the lower end of the spring (8) abuts against the limiting boss (60), the upper end of the pressure sensor nut (5) is provided with a gasket (15), and the upper end of the spring (8) abuts against the gasket (15).

8. The pressure sensor of claim 1, wherein, The lower shell (2) is provided with a drain hole (21), and the drain hole (21) communicates with a cavity where the spring (8) is located.

9. The pressure sensor of claim 1, wherein, The upper shell (1) is provided with a PCB (3), the Hall sensor (4) is arranged on the PCB (3), the upper end of the upper shell (1) is provided with a mounting protrusion (16), the PCB (3) is fixed on the mounting protrusion (16) through a screw (18), the PCB (3) is provided with a signal line (17), and the signal line (17) extends out of the upper shell (1).

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