Wave spring dampened pressure sensor

Abstract

The utility model discloses a wave spring damping pressure sensor. Wave spring damping pressure sensor includes: including the shell and inside setting pressure input cavity, pressure conversion cavity, damping filter cavity and tail cavity in proper order. Pressure is acted on the wave spring in pressure conversion cavity through the diaphragm of isolation, and is converted into mechanical displacement. The displacement is driven the porous piston movement in damping filter cavity through the force link, and extrudes the viscous damping substance filled in the cavity and flows through the micropore of piston self. Utilize the characteristic that viscous substance flow resistance is positive correlation with flow velocity, and fast displacement is strongly attenuated, and slow displacement is basically unblocked, realizes mechanical filtering. The displacement after filtering is detected by LVDT and is exported. The wave spring damping pressure sensor provided by the utility model filters out the interference on the mechanical level, has the advantages of strong anti -interference ability, no phase lag, system simplification, high reliability, is especially suitable for the industrial measurement and control scene with vibration or fluid pulsation.

Description

Technical Field

[0001] This utility model relates to the field of pressure sensor technology, and in particular to a wave spring damping pressure sensor. Background Technology

[0002] High-precision pressure measurement is crucial in fields such as industrial automation, scientific experiments, and medical diagnostics. However, actual measurement environments often contain various high-frequency, low-amplitude pressure interferences, such as turbulent pulsations in pipeline fluids, vibrations of mechanical equipment, and high-frequency harmonics in biological characteristics. These interference signals are superimposed on the steady-state or slowly varying pressure signal to be measured and are detected together by highly sensitive pressure sensors (such as piezoresistive, strain gauge, and piezoelectric sensors).

[0003] Currently, the industry generally adopts a passive processing mode of "sensing first, then filtering": first, the sensor outputs the raw electrical signal containing noise, and then the high-frequency components are suppressed by subsequent analog or digital electronic filters (such as low-pass filters). However, high-frequency noise has already entered the sensitive electrical signal chain and is highly susceptible to secondary pollution from electromagnetic interference, and the signal-to-noise ratio is already reduced before filtering; electronic filters, especially high-order filters designed to achieve good filtering effects, will inevitably produce phase lag for the useful signal, affecting the performance and stability of real-time control systems (such as active suspension and robot force control); additional filtering circuit design and debugging are required, increasing the system size, power consumption, cost, and potential failure points.

[0004] Therefore, it is necessary to provide a waveform spring damped pressure sensor to solve the above-mentioned technical problems. Utility Model Content

[0005] In view of the above situation and to overcome the defects of the existing technology, this utility model provides a waveform spring damping pressure sensor that can output a stable and interference-resistant pressure signal.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A wave spring damped pressure sensor includes: a housing, inside which are sequentially formed a pressure input chamber, a pressure conversion chamber, a damping filter chamber, and a tail chamber. The pressure input chamber and the pressure conversion chamber are sealed and separated by an isolation diaphragm. The pressure conversion chamber contains a pressure displacement transfer assembly, which includes a wave spring, a force transmission cover, and a force transmission rod, for converting pressure into displacement. A sealing cover with a sliding seal is provided between the pressure conversion chamber and the damping filter chamber.

[0007] The damping filter cavity contains a damping filter assembly, including a piston made of a porous material (such as sintered metal) and a viscous damping substance (such as silicone grease or magnetorheological fluid) filling the damping filter cavity and the tail cavity. The piston is connected to a force transmission rod. When the piston is driven to move, the viscous damping substance is squeezed and flows through the piston's own microporous structure. Rapid movement (corresponding to high-frequency interference) will encounter great viscous resistance and be suppressed, while slow movement (corresponding to real pressure changes) will pass through almost unimpeded, thus achieving mechanical filtering.

[0008] The detection assembly includes a fixed coil frame, a detection coil, and an iron core that moves with the piston, forming a displacement sensor (such as an LVDT) for detecting the filtered piston displacement. The signal processing unit, located outside the housing, processes the displacement signal and outputs the final pressure value.

[0009] Furthermore, a magnetic field adjustment coil can be installed outside the damping filter cavity. When the damping material is a magnetorheological fluid, the filtering characteristics can be adjusted in real time by changing the magnetic field strength.

[0010] Compared with the prior art, the present invention has the following beneficial effects: (1) The high-frequency pressure noise of this utility model is filtered out by viscous damping during the mechanical displacement stage and will not enter the subsequent electrical signal chain, thus fundamentally avoiding electromagnetic interference and improving the signal-to-noise ratio. (2) The mechanical filter of this utility model does not introduce the inherent phase delay of the electronic filter, which is beneficial to control systems that require fast and accurate feedback; (3) This utility model does not require a complex external electronic filter circuit, which reduces the number of system components, size and potential failure points. The core function is realized by a durable mechanical structure, which makes it more adaptable to the environment. (4) By using magnetorheological fluid and cooperating with an external magnetic field, this utility model can realize the electronic control adjustment of filtering characteristics to adapt to different working conditions. Attached Figure Description

[0011] Figure 1 A schematic diagram of the waveform spring damping pressure sensor provided by this utility model; Figure 2 for Figure 1 The diagram shows a cross-sectional view of the waveform spring-damped pressure sensor. Figure 3 for Figure 2 Enlarged structural diagram of section A; Figure 4 for Figure 1 A schematic diagram of one embodiment of the waveform spring-damped pressure sensor is shown below; Figure 5 for Figure 4The diagram shows a cross-sectional view of the waveform spring-damped pressure sensor.

[0012] The corresponding names of the attached figures are as follows: 1-outer shell, 2-pressure input chamber, 3-pressure conversion chamber, 4-damping filter chamber, 5-tail chamber, 6-isolation diaphragm, 7-wave spring, 8-sealing cover, 9-force transmission rod, 10-piston, 11-coil frame, 12-detection coil, 13-iron core, 14-connecting rod, 15-signal processing unit, 16-magnetic field adjustment assembly, 17-protective layer, 18-adjustment coil. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0014] Example 1: like Figure 1-5 As shown, the waveform spring damping pressure sensor provided by this utility model includes: a housing 1, and the interior of the housing 1 is divided into a pressure input chamber 2, a pressure conversion chamber 3, a damping filter chamber 4, and a tail chamber 5 by a partition or stepped hole structure.

[0015] A metal diaphragm 6 is welded or press-fitted to seal the pressure input chamber 2 and the pressure conversion chamber 3. This diaphragm senses the external medium pressure while simultaneously isolating the medium and protecting the internal structure. A pressure displacement transfer assembly is installed inside the pressure conversion chamber 3. This assembly includes a wave spring 7, with a force-transmitting cover press-fitted at each end. The upper force-transmitting cover is fixedly connected to the center of the diaphragm 6, while the lower force-transmitting cover is fixedly connected to the upper end of a force-transmitting rod 9. The wave spring 7 is moderately pre-compressed during installation to ensure it operates within its linear range. A sealing cover 8 is threaded or press-fitted to the pressure conversion chamber 3 and the damping filter chamber 4. The lower end of the force-transmitting rod 9 passes through this sealing cover 8 and extends into the damping filter chamber 4. An O-ring is installed in the center hole of the sealing cover 8, forming a sliding seal with the force-transmitting rod 9. This allows movement of the rod (force-transmitting rod 9) while preventing material from overflowing from the lower chamber.

[0016] A damping filter assembly is installed inside the damping filter cavity 4. The lower end of the force transmission rod 9 is fixedly connected to a piston 10 made of porous sintered bronze. Figure 2 As shown, the piston 10 has a large number of interconnected, micron-sized pores inside, forming a damping microporous structure. The damping filter cavity 4 and the tail cavity 5 connected to it are filled with high-viscosity silicone-based damping grease as a viscous damping material. The piston 10 is completely immersed in the damping grease.

[0017] The detection assembly is positioned between the damping filter chamber 4 and the tail chamber 5. A coil frame 11 is fixedly mounted on the housing 1, with a detection coil 12 (forming the primary and secondary coils of the LVDT) wound around it. The upper end of a connecting rod 14 is connected to the bottom of the piston 10, and the lower end is connected to a cylindrical iron core 13. The iron core 13 is precisely inserted into the center hole of the coil frame 11 and can slide freely within it.

[0018] A wire hole is provided at the end of the tail cavity 5. The lead wire of the detection coil 12 passes through this hole and connects to the signal processing unit 15 fixed on the side of the housing 1. The wire hole needs to be sealed with potting compound or other methods. The signal processing unit 15 is used to provide excitation for the detection coil 12, demodulate the voltage change caused by the displacement of the iron core 13, and finally output a standard pressure signal.

[0019] Working principle: The pressure of the measured medium acts on the isolation diaphragm 6, causing it to deform slightly. This deformation compresses the wave spring 7 via the upper force-transmitting cover, and the wave spring 7 linearly converts the pressure into displacement. This displacement is transmitted to the porous piston 10 via the lower force-transmitting cover and the force-transmitting rod 9.

[0020] When the input pressure is stable or changes slowly, the piston 10 moves slowly. The viscous damping grease is slowly compressed and flows smoothly from one side to the other through the micropores inside the piston 10, resulting in very low flow resistance. Therefore, the displacement of the piston 10 can be transmitted with almost no attenuation. At this time, the connecting rod 14 and the iron core 13 move synchronously with the piston 10, and the displacement detection component outputs a signal proportional to the pressure.

[0021] When the input pressure contains high-frequency pulsations or interference, these interferences attempt to drive the piston 10 to make rapid, minute movements. At this time, the damping grease needs to flow through the micropores at high speed, generating enormous viscous resistance, like encountering a "sticky wall," greatly consuming the energy of the rapid movement. This results in the piston 10 (and the connected iron core 13) hardly experiencing any corresponding high-frequency vibrations. The mechanical displacement caused by high-frequency interference is effectively filtered out.

[0022] Ultimately, the displacement detection component detects a smooth piston displacement signal that has been mechanically filtered. After being processed by the signal processing unit 15, a stable and pure pressure reading is output.

[0023] Example 2: like Figure 4-5As shown, based on Embodiment 1, a magnetic field adjustment component 16 is added to further enhance the adaptability of the sensor. Specifically, an adjustment coil 18, consisting of multiple turns of enameled wire, is wound around the outer casing 1 corresponding to the damping filter cavity 4. The coil is wrapped with an insulating protective layer 17, which is made of epoxy resin or plastic. The leads of the adjustment coil 18 are connected to an external adjustable current source.

[0024] In this embodiment, the viscous damping material filling the damping filter cavity 4 and the tail cavity 5 is replaced with magnetorheological fluid. Magnetorheological fluid is a smart fluid whose apparent viscosity changes significantly with the strength of the applied magnetic field.

[0025] Adjustable filtering principle: When the regulating coil 18 is not energized, the magnetorheological fluid is in its initial viscosity state, and the sensor has a basic filter cutoff frequency. When external interference characteristics change or measurement requirements change, different magnitudes of current can be applied to the regulating coil 18. The current generates a magnetic field, which penetrates the outer shell and acts on the magnetorheological fluid. As the magnetic field strengthens, the magnetic particles in the magnetorheological fluid form a chain-like structure, causing its apparent viscosity to rise sharply when flowing through the micropores of the piston 10, thereby increasing the damping force and raising the filter cutoff frequency. Conversely, reducing the current reduces the filtering strength. This allows the sensor of this invention to dynamically adapt to different working environments and achieve intelligent adjustment of filtering characteristics.

[0026] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A waveform spring-damped pressure sensor, characterized in that, include: The outer shell (1) has a pressure input chamber (2), a pressure conversion chamber (3), a damping filter chamber (4) and a tail chamber (5) formed in sequence inside it. An isolation diaphragm (6) is sealed and fixed between the pressure input chamber (2) and the pressure conversion chamber (3); The pressure displacement transfer assembly is located in the pressure conversion chamber (3) and includes a wave spring (7) and two force transmission covers connected to both ends of the wave spring (7). One force transmission cover is connected and fixed to the isolation diaphragm (6), and the other force transmission cover is fixedly connected to a force transmission rod (9). A sealing cover (8) is disposed between the pressure conversion chamber (3) and the damping filter chamber (4), and the force transmission rod (9) passes through the sealing cover (8) and slides thereto to seal; A damping filter assembly is disposed in the damping filter cavity (4) and includes a piston (10) and a viscous damping material filled in the damping filter cavity (4) and the tail cavity (5). One end of the piston (10) is fixedly connected to one end of the force transmission rod (9) that extends into the damping filter cavity (4). The piston (10) is made of porous material to form a damping microporous structure that allows the viscous damping material to flow through. The detection assembly includes a coil frame (11) fixedly disposed between the damping filter cavity (4) and the tail cavity (5), a detection coil (12) mounted on the coil frame (11), and an iron core (13) passing through the detection coil (12) and connected to the piston (10) via a connecting rod (14). The signal processing unit (15) is located outside the housing (1) and is connected to the detection coil (12) via a wire passing through the tail cavity (5).

2. The waveform spring damping pressure sensor according to claim 1, characterized in that, The viscous damping material is a silicon-based damping grease or a magnetorheological fluid.

3. A waveform spring damping pressure sensor according to claim 2, characterized in that, It also includes a magnetic field adjustment component (16), which includes an adjustment coil (18) wound around the outside of the damping filter cavity (4).

4. A waveform spring damping pressure sensor according to claim 3, characterized in that, The regulating coil (18) is covered with an insulating protective layer (17).

5. A waveform spring damping pressure sensor according to claim 1, characterized in that, The wave spring (7) is pre-compressed during installation.

6. A waveform spring damping pressure sensor according to claim 1, characterized in that, The sealing cover (8) and the force transmission rod (9) achieve a sliding seal through an O-ring.

7. A waveform spring damped pressure sensor according to claim 1, characterized in that, The piston (10) is made of sintered metal material.

8. A waveform spring-damped pressure sensor according to any one of claims 1-7, characterized in that, The tail cavity (5) has a central hole for the wire to pass through, and the central hole is sealed.

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