Single crystal silicon pressure difference sensor long-term stability test equipment

Abstract

This invention relates to the field of sensor testing technology, specifically to a long-term stability testing device for monocrystalline silicon differential pressure sensors. It includes a pressure regulating mechanism comprising a pressure chamber and high-pressure and low-pressure pipes disposed thereon. The pressure chamber has independent cavities respectively connected to the high-pressure and low-pressure pipes. The pressure regulating mechanism also includes pistons disposed in each independent cavity, each piston having a unidirectional pressure replenishment channel and a unidirectional pressure relief channel. Each piston is equipped with a baffle structure capable of closing the unidirectional pressure replenishment and unidirectional pressure relief channels individually or simultaneously. This invention ensures reliable switching between the pressure replenishment and pressure relief paths through the opening and closing control of the unidirectional pressure replenishment and unidirectional pressure relief channels via the baffle structure. Combined with piston movement, it achieves precise control and long-term stable maintenance of the pressure state within the independent cavities, providing a high-precision and high-stability testing environment for the long-term stability testing of monocrystalline silicon differential pressure sensors.

Description

Technical Field

[0001] This invention relates to the field of sensor testing technology, specifically to a long-term stability testing device for single-crystal silicon differential pressure sensors. Background Technology

[0002] A single-crystal silicon differential pressure sensor is a high-precision pressure measurement device based on a single-crystal silicon chip as the sensing element. Its working principle is as follows: the medium pressure is connected to the high-pressure side and the low-pressure side respectively, acting on the surface of the corresponding metal diaphragm. Under the action of the pressure difference, the metal diaphragm undergoes a slight deformation, squeezing out the silicone oil filling it, and transmitting the pressure difference to the core pressure chip. The pressure chip generates a corresponding electrical signal under the combined action of the pressures on both sides. This signal is received by the display board and processed by an algorithm to ultimately display the true differential pressure value of the measured medium.

[0003] Existing testing equipment generally suffers from problems such as low pressure control accuracy, slow pressurization response, inability to monitor sensor output changes in real time, and lack of automatic adjustment and protection functions. This results in poor repeatability and low efficiency of test results, making it difficult to accurately reflect the performance of sensors under complex operating conditions. In addition, some equipment does not consider the impact of environmental factors such as temperature fluctuations and pressure pulsations on test results, further limiting its application effectiveness.

[0004] A currently published Chinese patent, CN112729666B, discloses a high-stability single-crystal silicon differential pressure sensor. The sensor includes a sensor housing with a partition plate at its inner center. A single-crystal silicon sensor chip is mounted in the center of the partition plate. The left and right sides of the single-crystal silicon sensor chip are respectively a positive pressure chamber and a negative pressure chamber. A first overpressure protection film and a second overpressure protection film are respectively connected to the left and right sides of the single-crystal silicon sensor chip. A first measurement chamber is located on the side of the positive pressure chamber away from the first overpressure protection film. A first isolation corrugated sheet is installed at the port of the first measurement chamber at the first isolation corrugated sheet mounting opening. The negative pressure chamber... A second measuring chamber is provided on the side away from the second overpressure protection membrane. A second isolation corrugated sheet is installed at the port of the second measuring chamber. Multiple first oil passages are also circumferentially distributed in the positive pressure chamber of the sensor. The two ends of the first oil passages are connected to the first overpressure protection membrane and the first measuring chamber, respectively. Multiple second oil passages are also circumferentially distributed in the negative pressure chamber of the sensor. The two ends of the second oil passages are connected to the second overpressure protection membrane and the second measuring chamber, respectively. Adjacent first oil passages and adjacent second oil passages are connected by branch oil passages. The first oil passages, second oil passages and branch oil passages are filled with silicone oil.

[0005] According to the aforementioned patent, multiple uniformly distributed first and second oil passages are arranged around the chip, and adjacent first oil passages and adjacent second oil passages are connected by branch oil passages, thereby improving the measurement accuracy and precision of the single-crystal silicon sensor chip. However, in actual testing, overpressure or underpressure on the high-pressure or low-pressure inlet side may still adversely affect the test results. Furthermore, abnormal pressure may cause pressure imbalance within the oil circuit system, disrupting the originally uniform pressure distribution. Simply optimizing the oil circuit layout is insufficient to fully guarantee the sensor's testing stability under complex pressure environments. Therefore, there is a need for a device that combines effective pressure monitoring and automatic adjustment mechanisms to achieve high-precision, high-reliability long-term stability testing of single-crystal silicon differential pressure sensors. Summary of the Invention

[0006] To address the problems existing in the current technology, a long-term stability testing device for monocrystalline silicon differential pressure sensors is provided. By synchronously rotating the first and second sealing plates, reliable switching between the pressure replenishment path and the pressure relief path is ensured. Combined with piston movement, precise control and long-term stable maintenance of the pressure state within the independent cavity are achieved, providing a high-precision and high-stability testing environment for the long-term stability testing of monocrystalline silicon differential pressure sensors.

[0007] To address the problems of existing technologies, this invention provides a long-term stability testing device for a single-crystal silicon differential pressure sensor, comprising a pressure regulating mechanism. The pressure regulating mechanism includes a pressure chamber and a high-pressure pipe and a low-pressure pipe disposed thereon. The pressure chamber has independent cavities respectively connecting the high-pressure pipe and the low-pressure pipe. The high-pressure pipe and the low-pressure pipe are respectively used to connect to the high-pressure interface and the low-pressure interface of the single-crystal silicon differential pressure sensor. The pressure chamber has a high-pressure input port for connecting to the high-pressure pipe and a low-pressure input port for connecting to the low-pressure pipe. The pressure regulating mechanism also includes components disposed in each independent cavity. The piston is capable of linear reciprocating motion against its inner wall within an independent cavity. A one-way pressure-replenishing channel and a one-way pressure-relief channel are provided on the piston along its direction of motion. Each piston is equipped with a baffle structure capable of closing the one-way pressure-replenishing channel and the one-way pressure-relief channel individually or simultaneously. When both the one-way pressure-replenishing channel and the one-way pressure-relief channel are closed simultaneously, the independent cavity is in a sealed state. When only one-way pressure-replenishing channel is closed and the piston moves inward, the independent cavity is in a pressure-replenishing state. When only one-way pressure-relief channel is closed and the piston moves outward, the independent cavity is in a pressure-replenishing state.

[0008] Preferably, each independent cavity at the end of the pressure chamber is provided with a valve, and a pressure chamber is formed between the valve and the piston. The valve has a one-way medium inlet and a one-way medium outlet. When the baffle structure is activated, the one-way pressure replenishment channel and the one-way medium inlet are in a synchronous opening and closing state, and the one-way pressure relief channel and the one-way medium outlet are in a synchronous opening and closing state.

[0009] Preferably, the valve and piston can form a pressure replenishment path and a pressure relief path respectively connecting the pressure chamber under the action of the baffle structure. When the piston moves outward in the state of the pressure replenishment path, the pressure chamber is gradually compressed. When the piston moves inward in the state of the pressure relief path, the pressure chamber is gradually expanded.

[0010] Preferably, the baffle structure has a first sealing plate and a second sealing plate respectively disposed in the pressure chamber and closely attached to the piston and the valve. The first sealing plate has a first port that can connect to a one-way pressure replenishment channel or a one-way pressure relief channel, and the second sealing plate has a second port that can connect to a one-way medium inlet or a one-way medium outlet. The first port and the second port are coaxial.

[0011] Preferably, the end of the pressure chamber is provided with a pressure relief chamber that can connect the two pressure chambers, and the pressure relief chamber has a common air port for pressurizing and depressurizing the two pressure chambers respectively.

[0012] Preferably, a shaft is provided between the piston and the valve and is fixedly connected to the first sealing plate. The shaft has a retaining strip along the direction of piston movement that slides and engages with the second sealing plate and restricts the linear movement of the second sealing plate. When the shaft rotates, the first sealing plate and the second sealing plate are in a state of synchronous rotation.

[0013] Preferably, the shaft can drive the first sealing plate to move relative to the second sealing plate. The shaft is provided with a sealing ring for pressing the piston against the surface of the first sealing plate. The piston edge is provided with a rubber strip. The inner wall of the air pressure chamber is provided with a groove along the piston movement direction for the rubber strip to slide and engage therein, thereby restricting the piston from rotating.

[0014] Preferably, the air chamber is provided with a step for abutting the second sealing plate against the valve surface, located in the pressure chamber, and a pressure spring is provided between the step and the first sealing plate. The air chamber is provided with a pressure detector for detecting the amount of piston movement by the pressure received by the pressure spring.

[0015] Preferably, a stop bar extends from the valve toward the second sealing plate. An arc-shaped groove is provided on the back side of the second sealing plate for the end of the stop bar to be inserted therein. When the second sealing plate is rotated until the stop bar contacts the end of one side of the arc-shaped groove, the one-way pressure replenishment channel and the one-way medium inlet or the one-way pressure relief channel and the one-way medium outlet are in a connected state.

[0016] Preferably, the high-pressure pipe is provided with a first pressure sensor for real-time monitoring of the air pressure value output to the high-pressure interface of the monocrystalline silicon differential pressure sensor, and the low-pressure pipe is provided with a second pressure sensor for real-time monitoring of the air pressure value output to the low-pressure interface of the monocrystalline silicon differential pressure sensor.

[0017] The advantages of this application compared to the prior art are:

[0018] 1. This invention achieves precise regulation and long-term maintenance of the pressure state within an independent cavity by switching between the opening and closing of the unidirectional pressure replenishment channel and the unidirectional pressure relief channel through the piston movement in the pressure regulating mechanism in conjunction with the baffle structure.

[0019] By flexibly switching between pressure replenishment and pressure relief paths, the system ensures a rapid response and restoration of the set pressure in the event of pressure anomalies, effectively avoiding test errors caused by pressure fluctuations. This accurately reflects the performance changes of the single-crystal silicon differential pressure sensor after prolonged use, guaranteeing the continuity, accuracy, and reliability of the test data.

[0020] 2. This invention achieves accurate switching and reliable connection between the pressure replenishment path and the pressure relief path through the cooperation of the first and second sealing plates in the baffle structure, and the synchronous rotation of the first and second sealing plates driven by the shaft. With the piston tightly fitted to the first sealing plate via the sealing ring, and the second sealing plate tightly fitted to the valve via the step, the reliability of the switching between the pressure replenishment and pressure relief paths is ensured, preventing cross-contamination between the two paths that could lead to inaccurate pressure replenishment and pressure relief operations.

[0021] Meanwhile, through the synergistic effect of the pressure spring and the pressure detector, real-time monitoring and feedback control of the piston's motion state are achieved. Ultimately, this ensures the continuity, stability, and accuracy of the pressure regulation process, improving the reliability of the testing process.

[0022] 3. The present invention achieves precise switching between the pressure replenishment path and the pressure relief path at different rotational positions by using the arc groove on the second sealing plate and the limiting cooperation of the stop rod.

[0023] Meanwhile, the pressure delivered to both ends of the monocrystalline silicon differential pressure sensor is monitored and fed back in real time through the first and second pressure sensors installed on the high-pressure and low-pressure pipes, thereby accurately controlling the actual pressure value. This effectively improves the accuracy and response speed of pressure regulation, providing a high-precision and high-stability testing environment for the long-term stability testing of the monocrystalline silicon differential pressure sensor. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural schematic diagram of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention.

[0025] Figure 2This is a partial three-dimensional cross-sectional view of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention.

[0026] Figure 3 This is a three-dimensional structural diagram of the monocrystalline silicon differential pressure sensor of the present invention.

[0027] Figure 4 This is a three-dimensional structural diagram of the pressure adjustment mechanism of the long-term stability testing device for the single-crystal silicon differential pressure sensor of the present invention.

[0028] Figure 5 This is a partial three-dimensional cross-sectional view of the pressure adjustment mechanism of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention.

[0029] Figure 6 This is a schematic diagram showing the state in which the unidirectional pressure replenishment channel and the unidirectional pressure relief channel of the monocrystalline silicon differential pressure sensor long-term stability testing device of the present invention are simultaneously closed.

[0030] Figure 7 This is a schematic diagram of the single-crystal silicon differential pressure sensor long-term stability testing device of the present invention, showing the state where the unidirectional pressure compensation channel is opened and the unidirectional pressure relief channel is closed.

[0031] Figure 8 This is a schematic diagram of the single-crystal silicon differential pressure sensor long-term stability testing device of the present invention, showing the state where the unidirectional pressure compensation channel is closed and the unidirectional pressure relief channel is open.

[0032] Figure 9 This is a plan view of the second sealing plate and the stop bar of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention.

[0033] Figure 10 This is a partial three-dimensional cross-sectional view of the first sealing plate of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention, showing that it simultaneously closes the unidirectional pressure replenishment channel and the unidirectional pressure relief channel.

[0034] Figure 11 This is a partial three-dimensional cross-sectional view of the first sealing plate of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention, showing that the unidirectional pressure relief channel is closed while the unidirectional pressure replenishment channel is opened.

[0035] Figure 12 This is a partial three-dimensional cross-sectional view of the first sealing plate of the long-term stability testing device for the monocrystalline silicon differential pressure sensor of the present invention, showing that the unidirectional pressure relief channel is opened while the unidirectional pressure replenishment channel is closed.

[0036] The diagram is labeled as follows: 1. Monocrystalline silicon differential pressure sensor; 11. High-pressure interface; 12. Low-pressure interface; 2. Pressure regulating mechanism; 21. Pressure chamber; 211. Independent cavity; 2111. High-pressure input port; 2112. Low-pressure input port; 212. Pressure chamber; 213. Pressure relief chamber; 2131. Common air port; 22. High-pressure pipe; 221. First pressure sensor; 23. Low-pressure pipe; 231. Second pressure sensor; 3. Piston 31. One-way pressure replenishment channel; 32. One-way pressure relief channel; 33. Rubber strip; 4. Baffle structure; 41. First sealing plate; 411. First port; 412. Sealing ring; 42. Second sealing plate; 421. Second port; 422. Step; 4221. Pressure spring; 423. Stop bar; 4231. Arc groove; 5. Valve; 51. One-way medium inlet; 52. One-way medium outlet; 6. Shaft; 61. Locking strip. Detailed Implementation

[0037] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0038] See Figures 1-8 As shown, the long-term stability testing equipment for a single-crystal silicon differential pressure sensor includes a pressure regulating mechanism 2. The pressure regulating mechanism 2 includes a pressure chamber 21 and a high-pressure pipe 22 and a low-pressure pipe 23 disposed thereon. The pressure chamber 21 has independent cavities 211 respectively connecting the high-pressure pipe 22 and the low-pressure pipe 23. The high-pressure pipe 22 and the low-pressure pipe 23 are respectively used to connect to the high-pressure interface 11 and the low-pressure interface 12 of the single-crystal silicon differential pressure sensor 1. The pressure chamber 21 has a high-pressure input port 2111 for connecting to the high-pressure pipe 22 and a low-pressure input port 2112 for connecting to the low-pressure pipe 23. The pressure regulating mechanism 2 also includes pistons disposed in each independent cavity 211. 3. The piston 3 can reciprocate linearly against its inner wall in the independent cavity 211. The piston 3 is provided with a one-way pressure replenishment channel 31 and a one-way pressure relief channel 32 along its movement direction. Each piston 3 is provided with a baffle structure 4 that can close the one-way pressure replenishment channel 31 and the one-way pressure relief channel 32 separately or simultaneously. When the one-way pressure replenishment channel 31 and the one-way pressure relief channel 32 are closed at the same time, the independent cavity 211 is in a sealed state. When the one-way pressure replenishment channel 31 is closed alone and the piston 3 moves inward, the independent cavity 211 is in a pressure relief state. When the one-way pressure relief channel 32 is closed alone and the piston 3 moves outward, the independent cavity 211 is in a pressure replenishment state.

[0039] Before testing, correctly connect the single-crystal silicon differential pressure sensor 1 to the test system, ensuring that the high-pressure interface 11 is connected to the high-pressure tube 22 and the low-pressure interface 12 is connected to the low-pressure tube 23 to avoid measurement errors caused by reverse connection. Then, a medium, such as compressed air or inert gas, enters its respective independent cavity 211 through the high-pressure input port 2111 and the low-pressure input port 2112, filling the internal cavity of the single-crystal silicon differential pressure sensor 1 and acting on the metal diaphragm. At this time, the metal diaphragm undergoes a slight deformation under pressure, squeezing the internally filled silicone oil, thereby transmitting mechanical force to the pressure chip of the single-crystal silicon differential pressure sensor 1. The chip outputs a corresponding electrical signal based on the pressure difference between the two sides, which is processed by the display board in the single-crystal silicon differential pressure sensor 1 and converted into a readable pressure value.

[0040] To verify the long-term stability of the single-crystal silicon differential pressure sensor 1 under high-temperature conditions, the test equipment was equipped with a constant temperature control system, which can operate continuously within a set temperature range. The constant temperature control system is not shown in the figure.

[0041] During the long-term stability test of the monocrystalline silicon differential pressure sensor 1, the purpose of the test is to evaluate whether the measurement accuracy, repeatability, and zero-point drift of the monocrystalline silicon differential pressure sensor 1 remain stable after long-term use. To achieve this goal, the pressure value applied to the monocrystalline silicon differential pressure sensor 1 must be highly stable and repeatable throughout the entire test cycle to avoid introducing additional errors due to external pressure fluctuations or inaccurate control. To this end, the pressure regulating mechanism 2, through the reciprocating motion of the piston 3 in the independent cavity 211, combined with the opening and closing control of the unidirectional pressure replenishment channel 31 and the unidirectional pressure relief channel 32, achieves precise adjustment and maintenance of the pressure state at the high-pressure end and the low-pressure end.

[0042] At the start of the test, the pressure is first adjusted to the set value through a pressure replenishment operation. Then, with the pressure replenishment and pressure relief channels closed by the baffle structure 4, the independent cavity 211 is kept in a sealed state, thereby maintaining a constant pressure and simulating the long-term pressure environment of the single-crystal silicon differential pressure sensor 1 in actual applications.

[0043] If an abnormal pressure occurs during the test, such as excessively high or low pressure, the pressure regulating mechanism 2 can be quickly adjusted by the piston 3.

[0044] When the pressure on one side is detected to be higher than the set value, the corresponding piston 3 moves inward and closes the one-way pressure compensation channel 31, opening only the one-way pressure relief channel 32. This allows excess gas in the independent cavity 211 to be discharged through the one-way pressure relief channel 32, thereby reducing the pressure to the set value. Conversely, when the pressure is too low, the one-way pressure relief channel 32 is closed, the one-way pressure compensation channel 31 is opened, and the piston 3 moves outward, allowing external gas to enter the independent cavity 211 through the one-way pressure compensation channel 31, achieving pressure compensation.

[0045] By flexibly switching between the above-mentioned multiple adjustment states, a stable and controllable pressure environment can be maintained on the monocrystalline silicon differential pressure sensor 1 even under abnormal pressure conditions, ensuring the continuity and accuracy of test data and avoiding deviations in test results due to pressure input errors.

[0046] See Figure 2 and Figures 5-8 As shown, each independent cavity 211 at the end of the air pressure chamber 21 is provided with a valve 5. A pressure chamber 212 is formed between the valve 5 and the piston 3. The valve 5 has a one-way medium inlet 51 and a one-way medium outlet 52. When the baffle structure 4 is activated, the one-way pressure replenishment channel 31 and the one-way medium inlet 51 are in a synchronous opening and closing state, and the one-way pressure relief channel 32 and the one-way medium outlet 52 are in a synchronous opening and closing state.

[0047] When the baffle structure 4 is activated, and the one-way pressure replenishment channel 31 and the one-way medium inlet 51 are opened synchronously, as the piston 3 moves outward, the medium replenished in the pressure chamber 212 through the one-way medium inlet 51 is forced into the independent cavity 211 through the one-way pressure replenishment channel 31, ensuring that the external medium enters the pressure chamber 212 through the one-way pressure replenishment channel 31. Subsequently, the piston 3 moves inward to reset, at which point the pressure in the independent cavity 211 reaches the preset value, realizing the pressure replenishment operation and solving the problem of inaccurate testing due to insufficient pressure input.

[0048] When the baffle structure 4 is restarted, and the one-way pressure relief channel 32 and the one-way medium outlet 52 are opened synchronously, as the piston 3 moves inward, the overpressurized medium in the independent cavity 211 is forced into the pressure chamber 212 through the one-way pressure relief channel 32, ensuring that the internal medium enters the pressure chamber 212 through the one-way pressure relief channel 32. Subsequently, the piston 3 moves outward to reset, at which point the pressure in the independent cavity 211 reaches the preset value, while the excess medium discharged from the pressure chamber 212 is squeezed out through the one-way medium outlet 52, realizing the pressure relief operation and solving the problem of inaccurate testing due to excessive pressure input.

[0049] See Figure 2 and Figures 5-8 As shown, under the action of the baffle structure 4, the valve 5 and the piston 3 can respectively form a pressure replenishment path and a pressure relief path connecting the pressure chamber 212. When the piston 3 moves outward in the state of the pressure replenishment path, the pressure chamber 212 is gradually compressed. When the piston 3 moves inward in the state of the pressure relief path, the pressure chamber 212 is gradually expanded.

[0050] Under the action of the baffle structure 4, the valve 5 and the piston 3 can respectively form a pressure replenishment path and a pressure relief path connecting the pressure chamber 212. When the pressure replenishment path is formed, the piston 3 moves outward under the drive of external force, causing the volume of the pressure chamber 212 to gradually compress, the pressure inside the chamber to rise, and push the medium through the pressure replenishment path into the independent cavity 211 to achieve pressure replenishment.

[0051] When the pressure relief path is formed, piston 3 moves inward, the volume of pressure chamber 212 expands accordingly, the internal pressure decreases, and the excess medium in independent cavity 211 is discharged through the pressure relief path, thus completing the pressure release. Through the coordinated movement direction of piston 3 and the path state, effective control of pressure chamber 212 is achieved, ensuring the stability and continuity of the pressure replenishment and relief process.

[0052] See Figure 2 and Figures 5-8 As shown, the baffle structure 4 has a first sealing plate 41 and a second sealing plate 42 respectively attached to the piston 3 and the valve 5 in the pressure chamber 212. The first sealing plate 41 has a first port 411 that can connect to the one-way pressure replenishment channel 31 or the one-way pressure relief channel 32. The second sealing plate 42 has a second port 421 that can connect to the one-way medium inlet 51 or the one-way medium outlet 52. The first port 411 and the second port 421 are coaxial.

[0053] In the baffle structure 4, the first sealing plate 41 and the second sealing plate 42, located within the pressure chamber 212, are respectively in close contact with the piston 3 and the valve 5, serving to achieve sealing and channel switching functions. The first opening 411 on the first sealing plate 41 can correspond to either the one-way pressure replenishment channel 31 or the one-way pressure relief channel 32 on the piston 3. The second opening 421 on the second sealing plate 42 can correspond to either the one-way medium inlet 51 or the one-way medium outlet 52 of the valve 5.

[0054] Since the first port 411 and the second port 421 are on the same axis, it is ensured that during the operation of the baffle structure 4, the two ports can be connected to the corresponding pressure replenishment or pressure relief path, thereby realizing reliable connection and state switching of the pressure replenishment path and pressure relief path of the medium flow, and ensuring the continuity and accuracy of the pressure regulation process.

[0055] See Figure 4 and Figure 5 As shown, the end of the pressure chamber 21 is provided with a pressure relief chamber 213 that can connect two pressure chambers 212. The pressure relief chamber 213 has a common air port 2131 for pressurizing and depressurizing the two pressure chambers 212 respectively.

[0056] When one of the pressure chambers 212 needs to be pressurized, the external medium is supplied to the pressure relief chamber 213 through the common air port 2131, and the medium then enters the corresponding pressure chamber 212 through the one-way medium inlet 51 to complete the pressurization.

[0057] When the pressure chamber 212 needs to be depressurized, the excess medium inside the chamber is discharged through the one-way medium outlet 52 to the pressure relief chamber 213 and finally released through the common air port 2131, thus realizing the depressurization operation. The existence of the pressure relief chamber 213 allows the two pressure chambers 212 to share a channel during the pressure replenishment and depressurization processes, improving control efficiency.

[0058] See Figures 5-8 and Figures 10-12 As shown, a shaft 6 is rotatably connected to the first sealing plate 41 between the piston 3 and the valve 5. The shaft 6 has a retaining strip 61 along the movement direction of the piston 3 that slides and engages with the second sealing plate 42 and restricts the linear movement of the second sealing plate 42. When the shaft 6 rotates, the first sealing plate 41 and the second sealing plate 42 are in a state of synchronous rotation.

[0059] The rotary drive used to drive the rotation of shaft 6 is not shown in the figure.

[0060] When the shaft 6 rotates, the linkage between the retaining strip 61 and the second sealing plate 42 drives the second sealing plate 42 to rotate synchronously with the first sealing plate 41, thereby achieving the consistency of angle and synchronization of action of the two sealing plates during the movement process, ensuring accurate alignment during the switching process of pressure replenishment path and pressure relief path.

[0061] See Figures 5-8 and Figures 10-12 As shown, the shaft 6 can drive the first sealing plate 41 to move relative to the second sealing plate 42. The shaft 6 is provided with a sealing ring 412 for the piston 3 to abut against the surface of the first sealing plate 41. The piston 3 is provided with a rubber strip 33 on its edge. The inner wall of the air pressure chamber 21 is provided with a groove along the movement direction of the piston 3 for the rubber strip 33 to slide and be engaged therein, and to restrict the piston 3 from rotating.

[0062] The push-pull driver used to drive the movement of shaft 6 is not shown in the figure.

[0063] When the shaft 6 moves the first sealing plate 41 relative to the second sealing plate 42, the piston 3 moves to perform pressure replenishment and pressure relief operations. Simultaneously, because the sealing ring 412 on the shaft 6 presses the piston 3 tightly against the surface of the first sealing plate 41, a stable seal is ensured, preventing media cross-contamination between the pressure replenishment and pressure relief paths and thus affecting the pressure replenishment and pressure relief operations. Since the rubber strip 33 on the edge of the piston 3 is embedded in a groove opened along the direction of movement on the inner wall of the pressure chamber 21, the rotation of the piston 3 is restricted when the shaft 6 rotates, allowing it to move only in a straight line.

[0064] This allows the first sealing plate 41 to rotate relative to the piston 3, ensuring that the first port 411 on the first sealing plate 41 can connect with the one-way pressure replenishment channel 31 and the one-way pressure relief channel 32 respectively. This achieves effective control over the guiding and sealing of the piston 3's movement, ensuring the smoothness and accuracy of the pressure regulation process.

[0065] See Figures 5-8 and Figures 10-12 As shown, the air pressure chamber 21 is provided with a step 422 for abutting the second sealing plate 42 against the surface of the valve 5 in the pressure chamber 212. A pressure spring 4221 is provided between the step 422 and the first sealing plate 41. The air pressure chamber 21 is provided with a pressure detector for detecting the movement of the piston 3 by the pressure received by the pressure spring 4221.

[0066] The pressure detector is not shown in the figure.

[0067] When piston 3 moves within pressure chamber 212, the step 422 structure within pressure chamber 21 presses the second sealing plate 42 against the surface of valve 5, ensuring its sealing stability. Simultaneously, the pressure spring 4221, positioned between step 422 and the first sealing plate 41, compresses or extends with the movement of piston 3, changing its stress state. At this time, the pressure detector on pressure chamber 21 senses the pressure changes experienced by pressure spring 4221, reflecting the displacement and movement trend of piston 3 in real time.

[0068] This ensures accurate detection of the position and stroke of piston 3 during its movement, providing reliable feedback for pressure regulation and thus guaranteeing stable operation and control accuracy of the test.

[0069] See Figures 6-12 As shown, a stop bar 423 extends from the valve 5 toward the second sealing plate 42. An arc-shaped groove 4231 is provided on the back side of the second sealing plate 42 for the end of the stop bar 423 to be inserted therein. When the second sealing plate 42 is rotated to the point where the stop bar 423 contacts one end of the arc-shaped groove 4231, the one-way pressure replenishment channel 31 and the one-way medium inlet 51 or the one-way pressure relief channel 32 and the one-way medium outlet 52 are in a connected state.

[0070] When the second sealing plate 42 rotates under the drive of the shaft 6, the end of the stop rod 423 extending from the valve 5 is always inserted into the arc-shaped groove 4231 on its back side. As the rotation proceeds, when the second sealing plate 42 rotates to the point where the stop rod 423 contacts the end of one side of the arc-shaped groove 4231, this position corresponds to the set channel switching state. At this time, accurate communication is achieved between the one-way pressure replenishment channel 31 and the one-way medium inlet 51, or between the one-way pressure relief channel 32 and the one-way medium outlet 52. Through the limiting cooperation between the stop rod 423 and the arc-shaped groove 4231, the positioning accuracy of the second sealing plate 42 in different working positions is ensured, thereby guaranteeing the reliability and sealing performance of the pressure replenishment and pressure relief path switching.

[0071] When the second sealing plate 42 is rotated so that the stop rod 423 is located in the middle of the arc groove 4231, that is, when the second sealing plate 42 is rotated 90° in both directions, the stop rod 423 can be located in the middle of the arc groove 4231. At this time, both the pressure replenishment path and the pressure relief path are closed, indicating that the independent cavity 211 is in a constant pressure state and no pressure replenishment or pressure relief adjustment is required. At this time, the single crystal silicon differential pressure sensor 1 is tested normally.

[0072] See Figure 2 and Figure 4 As shown, the high-pressure tube 22 is equipped with a first pressure sensor 221 for real-time monitoring of the air pressure value output to the high-pressure interface 11 of the monocrystalline silicon differential pressure sensor 1, and the low-pressure tube 23 is equipped with a second pressure sensor 231 for real-time monitoring of the air pressure value output to the low-pressure interface 12 of the monocrystalline silicon differential pressure sensor 1.

[0073] When the high-pressure pipe 22 supplies gas pressure medium to the high-pressure interface 11 of the monocrystalline silicon differential pressure sensor 1, the first pressure sensor 221 installed on the high-pressure pipe 22 monitors the current pressure value in real time to ensure that the output pressure meets the set requirements. At the same time, the second pressure sensor 231 on the low-pressure pipe 23 also monitors the gas pressure value supplied to the low-pressure interface 12 to ensure that the low-pressure side pressure is stable and controllable.

[0074] Through real-time feedback from the first pressure sensor 221 and the second pressure sensor 231, the actual pressure state of the high-pressure end and the low-pressure end of the monocrystalline silicon differential pressure sensor 1 can be accurately grasped, providing a reliable basis for subsequent pressure regulation and the accuracy of test data.

[0075] This invention achieves precise control and long-term stable maintenance of the pressure state within the independent cavity 211 through the cooperation of the piston 3 and the baffle structure 4 in the pressure regulating mechanism 2. During this process, the synchronous rotation of the first sealing plate 41 and the second sealing plate 42, along with their tight fit with the piston 3 and the valve 5, ensures reliable switching and sealing between the pressure replenishment path and the pressure relief path, preventing media cross-contamination from affecting the regulating accuracy.

[0076] Meanwhile, the positioning accuracy of switching between the pressure replenishment path and the pressure relief path is further improved by utilizing the limiting cooperation between the arc groove 4231 and the stop rod 423. Combined with the feedback mechanism of the pressure spring 4221 and the pressure detector, real-time monitoring and closed-loop control of the piston 3's motion state are realized. This provides a high-precision and high-stability testing environment for the long-term stability testing of the single-crystal silicon differential pressure sensor 1, ensuring the authenticity and reliability of the test data.

[0077] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A long-term stability testing device for a single-crystal silicon differential pressure sensor, characterized in that, It includes a pressure regulating mechanism (2), which includes a pressure chamber (21) and a high-pressure pipe (22) and a low-pressure pipe (23) disposed thereon; The pressure chamber (21) has independent cavities (211) that are respectively connected to the high-pressure pipe (22) and the low-pressure pipe (23). The high-pressure pipe (22) and the low-pressure pipe (23) are respectively used to connect the high-pressure interface (11) and the low-pressure interface (12) of the single-crystal silicon differential pressure sensor (1). The pressure chamber (21) is provided with a high-pressure input port (2111) for connecting to the high-pressure pipe (22) and a low-pressure input port (2112) for connecting to the low-pressure pipe (23). The pressure regulating mechanism (2) also includes pistons (3) respectively disposed in each independent cavity (211). The pistons (3) are able to reciprocate linearly against the inner wall of the independent cavity (211). The pistons (3) are provided with a one-way pressure replenishment channel (31) and a one-way pressure relief channel (32) along their movement direction. Each piston (3) is provided with a baffle structure (4) that can close the one-way pressure replenishment channel (31) and the one-way pressure relief channel (32) respectively or simultaneously. When the one-way pressure replenishment channel (31) and the one-way pressure relief channel (32) are closed at the same time, the independent cavity (211) is in a sealed state; When the unidirectional pressure channel (31) is closed alone and the piston (3) moves inward, the independent cavity (211) is in a depressurized state; When the one-way pressure relief channel (32) is closed alone and the piston (3) moves outward, the independent cavity (211) is in a pressurized state.

2. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 1, characterized in that, Each independent cavity (211) at the end of the air pressure chamber (21) is provided with a valve (5). A pressure chamber (212) is formed between the valve (5) and the piston (3). The valve (5) has a one-way medium inlet (51) and a one-way medium outlet (52). When the baffle structure (4) is activated, the one-way pressure replenishment channel (31) and the one-way medium inlet (51) are in a synchronous opening and closing state, and the one-way pressure relief channel (32) and the one-way medium outlet (52) are in a synchronous opening and closing state.

3. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 2, characterized in that, Under the action of the baffle structure (4), the valve (5) and the piston (3) can respectively form a pressure replenishment path and a pressure relief path connecting the pressure chamber (212). When the piston (3) moves outward under the pressure replenishment path, the pressure chamber (212) is gradually compressed. When the piston (3) moves inward under the pressure relief path, the pressure chamber (212) is gradually expanded.

4. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 3, characterized in that, The baffle structure (4) has a first sealing plate (41) and a second sealing plate (42) respectively attached to the piston (3) and valve (5) in the pressure chamber (212). The first sealing plate (41) has a first port (411) that can connect to the one-way pressure replenishment channel (31) or the one-way pressure relief channel (32). The second sealing plate (42) has a second port (421) that can connect to the one-way medium inlet (51) or the one-way medium outlet (52). The first port (411) and the second port (421) are coaxial.

5. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 4, characterized in that, The end of the pressure chamber (21) is provided with a pressure relief chamber (213) that can connect two pressure chambers (212). The pressure relief chamber (213) has a common air port (2131) for pressurizing and depressurizing the two pressure chambers (212) respectively.

6. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 4, characterized in that, A shaft (6) is fixedly connected to the first sealing plate (41) for rotation between the piston (3) and the valve (5). The shaft (6) has a retaining strip (61) that slides and engages with the second sealing plate (42) along the direction of movement of the piston (3) and restricts the linear movement of the second sealing plate (42). When the shaft (6) rotates, the first sealing plate (41) and the second sealing plate (42) are in a state of synchronous rotation.

7. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 6, characterized in that, The shaft (6) can drive the first sealing plate (41) to move relative to the second sealing plate (42). The shaft (6) is provided with a sealing ring (412) for the piston (3) to abut against the surface of the first sealing plate (41). The piston (3) is provided with a rubber strip (33) on its edge. The inner wall of the air pressure chamber (21) is provided with a groove along the direction of piston (3) movement for the rubber strip (33) to slide and engage therein and restrict the piston (3) from rotating.

8. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 7, characterized in that, A step (422) is provided on the air chamber (21) and in the pressure chamber (212) for abutting the second sealing plate (42) against the surface of the valve (5). A pressure spring (4221) is provided between the step (422) and the first sealing plate (41). A pressure detector is provided on the air chamber (21) for detecting the movement of the piston (3) by the pressure received by the pressure spring (4221).

9. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 4, characterized in that, A stop bar (423) extends from the valve (5) toward the second sealing plate (42). An arc-shaped groove (4231) is provided on the back side of the second sealing plate (42) for inserting the end of the stop bar (423). When the second sealing plate (42) rotates to the point where the stop bar (423) contacts the end of one side of the arc-shaped groove (4231), the one-way pressure replenishment channel (31) and the one-way medium inlet (51) or the one-way pressure relief channel (32) and the one-way medium outlet (52) are in a connected state.

10. The long-term stability testing equipment for a single-crystal silicon differential pressure sensor according to claim 1, characterized in that, The high-pressure tube (22) is equipped with a first pressure sensor (221) for real-time monitoring of the air pressure value output to the high-pressure interface (11) of the monocrystalline silicon differential pressure sensor (1), and the low-pressure tube (23) is equipped with a second pressure sensor (231) for real-time monitoring of the air pressure value output to the low-pressure interface (12) of the monocrystalline silicon differential pressure sensor (1).

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