Pressure sensor and contact force sensing device

Abstract

A pressure sensor and a contact force sensing device, the pressure sensor comprising: a main body portion having a first side and a second side opposite to each other, the main body portion having a hollow portion communicating the first side and the second side; the first membrane is connected to the first side and seals an opening, located in the first side, of the hollow part; the sensor chip is connected to the second side and seals an opening, located in the second side, of the hollow part, and the hollow part is filled with a pressure transmitting medium so that the pressure received by the first diaphragm can be transmitted to the sensor chip; the optical fiber is arranged on the side, away from the first diaphragm, of the sensor chip, the optical fiber is used for emitting a detection optical signal to the sensor chip and receiving a feedback optical signal, and the feedback optical signal is at least used for representing the pressure received by the sensor chip. By adopting the technical scheme of the invention, the force measurement precision of the sensor and the stability of dynamic mechanical measurement can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensors, and in particular to a pressure sensor and a contact force sensing device. Background Art

[0002] Existing pressure sensor technology mainly uses a variety of physical effects to achieve pressure detection. Typical structures include piezoresistive, capacitive, piezoelectric, and traditional optical types. Among them, piezoresistive sensors sense pressure through the resistance change of a single-crystal silicon diaphragm. Although they have high precision and linearity, their performance is easily affected by temperature fluctuations and they need to rely on compensation circuits to maintain stability. In addition, the output signal is sensitive to electromagnetic interference. Capacitive sensors use the capacitance difference caused by changes in electrode spacing. Although they have high sensitivity and good temperature stability, their high output impedance and parasitic capacitance effects limit their load capacity and measurement accuracy. The nonlinear output characteristics also increase the difficulty of calibration. Piezoelectric sensors rely on the charge response of piezoelectric materials and are good at dynamic pressure measurement, but cannot detect static pressure. In addition, the material properties are easily affected by environmental humidity and require additional protection.

[0003] Traditional optical sensors monitor pressure by detecting changes in light intensity or phase. They are resistant to electromagnetic interference and suitable for use in extreme environments such as high temperatures and corrosion. However, in practical applications, traditional fiber-optic pressure sensors do have significant directional measurement limitations, and their pressure response characteristics are highly dependent on the direction of diaphragm deformation. When the measured pressure direction is at a large angle to the diaphragm surface normal, the diaphragm's deformation mode shifts from pure axial compression to a complex deformation involving bending and shearing. This not only leads to a sharp decrease in optical signal modulation efficiency but also introduces nonlinear measurement errors. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide an improved pressure sensor and contact force sensing device.

[0005] To solve the above technical problems, an embodiment of the present invention provides a pressure sensor, comprising: a main body having a first side and a second side relative to each other, the main body having a hollow part connecting the first side and the second side; a first diaphragm connected to the first side and closing the opening of the hollow part located on the first side; a sensor chip connected to the second side and closing the opening of the hollow part located on the second side, the hollow part being filled with a pressure-transmitting medium to transmit the pressure received by the first diaphragm to the sensor chip; an optical fiber being arranged on the side of the sensor chip facing away from the first diaphragm, the optical fiber being used to transmit a detection light signal to the sensor chip and receive a feedback light signal, the feedback light signal being used at least to characterize the pressure received by the sensor chip.

[0006] Optionally, the sensor chip includes: a base, attached to the second side; a second diaphragm, arranged on the base and located between the base and the hollow portion, a sealed cavity is formed between the base and the second diaphragm, the second diaphragm is suitable for generating corresponding deformation according to the pressure change of the pressure transmission medium in the hollow portion, and the feedback light signal carries the deformation information of the second diaphragm.

[0007] Optionally, the second membrane is at least partially exposed at an opening of the hollow portion toward the second side.

[0008] Optionally, the hollow portion includes a first cavity and a second cavity that are interconnected, wherein the first cavity is closer to the first diaphragm than the second cavity, and the first cavity and the second cavity are connected via a first through hole.

[0009] Optionally, the cross-sectional area of ​​the first through hole is smaller than the cross-sectional area of ​​the second cavity to form a step structure at the connection between the first through hole and the second cavity, and a first sealing structure is arranged between the step structure and the sensor chip, wherein, in the direction from the first side to the second side, the first sealing structure avoids the first diaphragm.

[0010] Optionally, a mounting groove is further formed on the second side of the main body for accommodating at least a portion of the sensor chip, and the mounting groove is communicated with the second cavity.

[0011] Optionally, the main body is further provided with a second through hole communicating with the hollow portion, wherein the second through hole is used for injecting a pressure-transmitting medium into the hollow portion, and further comprises: a sealing plug for closing the second through hole.

[0012] Optionally, the pressure sensor also includes: a base connected to the second side, the sensor chip is located between the base and the main body, the base is provided with a third through hole extending in a direction from the first side to the second side, and the optical fiber transmits the detection light signal to the sensor chip through the third through hole and receives the feedback light signal.

[0013] Optionally, at least a portion of the optical fiber is inserted into the third through hole, and an outer peripheral surface of the optical fiber is directly or indirectly connected to an inner wall of the third through hole.

[0014] Optionally, the pressure sensor further includes: an optical collimator, at least partially extending into the third through hole and optically coupled to an end of the optical fiber facing the sensor chip.

[0015] Optionally, a second sealing structure is provided between the base and the main body, and the second sealing structure is provided around the third through hole.

[0016] In order to solve the above technical problems, an embodiment of the present invention also provides a contact force sensing device, including: a shell, having a accommodating cavity; the above-mentioned pressure sensor, the shell is provided with an assembly hole to expose at least the first side of the pressure sensor, and at least the second side of the pressure sensor is located in the accommodating cavity; a force guiding mechanism, connected to the shell and having a first end and a second end relative to each other, the first end contacts the first diaphragm, and the second end directly or indirectly contacts the object to be measured to transmit the contact force exerted on the object to be measured to the first diaphragm.

[0017] Optionally, the housing is further provided with a plug hole, and the end of the optical fiber facing away from the sensor chip is directly or indirectly optically coupled to an optoelectronic device through the plug hole.

[0018] Optionally, the contact force sensing device further includes: a coupler, one end of which is optically coupled to the optical fiber along the extension direction, and the other end of the coupler is exposed to the plug hole and is pluggably connected to the optoelectronic device.

[0019] Optionally, the force-guiding mechanism includes: a sleeve portion having a third end and a fourth end relative to each other along the extension direction, the third end being connected to the pressure sensor, the sleeve portion having an accommodating channel, docked with and connected to the assembly hole; a pressure block portion, accommodated in the accommodating channel and in contact with the first diaphragm; a spring structure, accommodated in the accommodating channel, and located on the side of the pressure block portion away from the first diaphragm, the spring structure deforms under the pressure of the object to be measured, and transmits the reaction force generated by the deformation to the first diaphragm.

[0020] Optionally, a buffer structure is provided on a side of the pressing block portion facing the first diaphragm.

[0021] Optionally, the contact force sensing device further includes: a pressure cover portion, which is accommodated in the accommodating channel and covers at least a portion of the spring structure on a side facing away from the pressure block portion, wherein the pressure cover portion is suitable for connecting with the object to be measured, and as the object to be measured moves under pressure, the pressure cover portion reciprocates along the accommodating channel.

[0022] Optionally, the contact force sensing device is used to monitor the contact force applied to the pantograph, wherein the pantograph includes a spring box, and the spring box includes: a shell with a telescopic part built in, and the telescopic part extends or retracts into the shell under the action of the contact force applied to the pantograph, the shell and the sleeve part are fixedly connected, the telescopic part and the pressure cover part are fixedly connected, and the pressure cover part reciprocates along the accommodating channel with the movement of the telescopic part.

[0023] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0024] An embodiment of the present invention provides a pressure sensor, comprising: a main body having a first side and a second side opposite to each other, the main body having a hollow portion connecting the first side and the second side; a first diaphragm connected to the first side and closing the opening of the hollow portion located on the first side; a sensor chip connected to the second side and closing the opening of the hollow portion located on the second side, the hollow portion being filled with a pressure-transmitting medium to transmit the pressure received by the first diaphragm to the sensor chip; an optical fiber arranged on a side of the sensor chip facing away from the first diaphragm, the optical fiber being used to transmit a detection light signal to the sensor chip and receive a feedback light signal, the feedback light signal being used at least to characterize the pressure received by the sensor chip.

[0025] Compared to traditional pressure sensors that typically rely on direct modulation of optical signals by a pressure-sensitive membrane, whose sensitivity is easily affected by the uniformity of membrane deformation and installation stress, and whose optical path calibration requires repeated adjustments, this solution introduces a pressure-transmitting medium as a pressure transmission medium. This solution utilizes the hydrostatic pressure characteristics of the fluid to evenly transmit the force exerted on the membrane to the sensor chip, effectively eliminating the measurement errors caused by localized membrane deformation in traditional structures and improving the measurement accuracy of the pressure sensor. Furthermore, the damping effect of the pressure-transmitting medium significantly improves the stability of dynamic pressure measurements.

[0026] Furthermore, the pressure sensor includes a base connected to the second side of the main body, and a third through-hole is formed in the base. The optical fiber transmits the detection light signal to the sensor chip and receives the feedback light signal through the third through-hole. This ensures that the detection light signal and the feedback light signal are more stably transmitted between the sensor chip and the optical fiber.

[0027] Furthermore, the sealed packaging of the entire pressure sensor can be achieved through the first sealing structure and the second sealing structure. The structure is simple and easy to process, which is conducive to reducing production costs.

[0028] An embodiment of the present invention also provides a contact force sensing device, comprising: a shell having a accommodating cavity; the above-mentioned pressure sensor, wherein the shell is provided with an assembly hole to expose at least the first side of the pressure sensor, and at least the second side of the pressure sensor is located in the accommodating cavity; a force guiding mechanism, connected to the shell and having a first end and a second end relative to each other, the first end passing through the assembly hole and contacting the first diaphragm, and the second end directly or indirectly contacting the object to be measured to transmit the contact force exerted on the object to be measured to the first diaphragm.

[0029] By adopting the technical solution of the present application, the first side of the pressure sensor is exposed for contact with the force-guiding mechanism through an assembly hole opened in the housing of the contact force sensing device, while the second side is placed in the accommodating cavity. In this way, the various components are rationally integrated together, effectively reducing the volume of the entire device, making it more advantageous in application scenarios with limited space, facilitating installation and layout, and improving space utilization. Furthermore, the first end of the force-guiding mechanism contacts the first diaphragm of the pressure sensor through the assembly hole, and the second end directly or indirectly contacts the object to be measured, forming a clear and direct force conduction path. In this way, it can be ensured that the contact force exerted on the object to be measured can be accurately transmitted to the first diaphragm of the pressure sensor, reducing the loss and deviation of the force during the transmission process, thereby improving the accuracy of the force measurement.

[0030] Furthermore, the force-guiding mechanism includes a sleeve portion, a pressure block portion, and a spring structure. Through the coordinated action of these components, a closed-loop conduction chain of "pressure-deformation-reaction force" is formed. The nonlinear compression characteristics of the spring structure can automatically compensate for the unevenness of the contact surface, making the pressure distribution more uniform, reducing the risk of local stress concentration, and improving measurement consistency. In actual applications, when the object to be measured is compressed and displaced, the pressure cover portion pushes the spring structure to deform. The spring structure disperses the concentrated force into a uniformly distributed load through elastic deformation, avoiding the direct impact of local stress concentration on the first diaphragm in traditional rigid connections. Furthermore, the compression amount (displacement) of the spring structure is nonlinearly related to the conduction force (Hooke's law). The object to be measured may produce a large displacement under the action of the contact force, while the force actually borne by the pressure sensor is smoothly transmitted, preventing the pressure sensor from being overloaded due to sudden changes in displacement.

[0031] Furthermore, through the setting of the socket and the coupler, the optoelectronic device (such as the grating demodulator) can be plug-and-play through the coupler, and the use of the contact force sensing device is more convenient, which is conducive to reducing the on-site debugging cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of a contact force sensing device according to an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 A cross-sectional view of the structure shown along the AA direction;

[0034] Figure 3 yes Figure 1 Exploded view of the middle shell and its internal structure;

[0035] Figure 4 yes Figure 1 Exploded diagram of the intermediate guidance mechanism;

[0036] Figure 5 yes Figure 1 Schematic diagram of the pressure sensor from another perspective;

[0037] Figure 6 yes Figure 5 Exploded view of the structure shown;

[0038] Figure 7 yes Figure 5 A cross-sectional view of the structure shown along direction BB;

[0039] Figure 8 yes Figure 1 Schematic diagram of the coordination between the structure shown and the spring box. DETAILED DESCRIPTION

[0040] In recent years, China's urbanization rate has continued to rise, with population migration to cities resulting in a rapid increase in urban populations and increasing pressure on urban transportation. Compared to other urban transportation modes, urban rail transit is the most efficient public transportation option and one of the best solutions to urban mobility problems. This is because rail transit's greatest advantage is its high capacity, with a transport capacity approximately seven to ten times that of cars and buses, providing convenience for residents. Furthermore, subways operate at high speeds, reaching speeds of up to 100 kilometers per hour, saving significant travel time. Therefore, rail transit has become a primary means of transportation for people, and dense crowds pose serious challenges to subway operational safety.

[0041] When the electric passenger car is running, the contact force between the pantograph and the wires changes randomly due to the vibration of the pantograph network, resulting in unstable contact force and easy mechanical and electrical damage. In addition, although the mileage of urban rail transit is getting longer, the number of lines is increasing, and the number of trains is increasing, which is more convenient for people to travel, the number of operation and maintenance personnel of rail transit is decreasing, and the age structure is becoming more and more aging, resulting in the operation and maintenance timeliness of the relationship between the pantograph and the wires becoming worse and worse.

[0042] Therefore, it is necessary to provide an effective, safe, and intelligent monitoring solution that can monitor the relationship between the pantograph and the power line (or catenary, contact wire) in real time. For example, pressure sensors can be used to monitor the contact force between the pantograph and the power line, enabling intuitive monitoring of the contact force between the pantograph and the power line on electric buses.

[0043] However, as mentioned in the background art, existing pressure sensors have poor measurement stability and are relatively complicated to use.

[0044] To address at least one of the aforementioned technical issues, embodiments of the present invention provide a pressure sensor and a contact force sensing device. The pressure sensor comprises: a main body having a first side and a second side facing each other, the main body having a hollow portion connecting the first and second sides; a first diaphragm connected to the first side and sealing an opening of the hollow portion located on the first side; a sensor chip connected to the second side and sealing the opening of the hollow portion located on the second side, the hollow portion being filled with a pressure-transmitting medium to transmit pressure received by the first diaphragm to the sensor chip; and an optical fiber disposed on a side of the sensor chip facing away from the first diaphragm, the optical fiber being configured to transmit a detection light signal to the sensor chip and receive a feedback light signal, the feedback light signal being configured to at least represent the pressure received by the sensor chip.

[0045] The technical solution of this application introduces a pressure-transmitting medium as the pressure transmission medium, leveraging the hydrostatic properties of the fluid to evenly transmit the force exerted on the diaphragm to the sensor chip. This effectively eliminates measurement errors caused by localized diaphragm deformation in traditional structures, improving the pressure sensor's measurement accuracy. Furthermore, the damping effect of the pressure-transmitting medium significantly enhances the stability of dynamic pressure measurements.

[0046] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0047] Figure 1 is a schematic diagram of a contact force sensing device 100 according to an embodiment of the present invention. Figure 2 yes Figure 1 The structure is shown in a cross-sectional view along the AA direction.

[0048] Combine Figure 1 and Figure 2 The contact force sensing device 100 may include a pressure sensor 10 and a force guiding mechanism 30 .

[0049] The specific structure of the pressure sensor 10 can be referred to Figures 5 to 7 .

[0050] In some embodiments, combined Figures 5 to 7The pressure sensor 10 may include a main body 1 having a first side 11 and a second side 12 relative to each other, the main body 1 having a hollow portion 13 connecting the first side 11 and the second side 12; a first diaphragm 2, connected to the first side 11 and closing the opening of the hollow portion 13 located on the first side 11; a sensor chip 3, connected to the second side 12 and closing the opening of the hollow portion 13 located on the second side 12, the hollow portion 13 is filled with a pressure transmission medium to transmit the pressure received by the first diaphragm 2 to the sensor chip 3; an optical fiber 4, arranged on the side of the sensor chip 3 away from the first diaphragm 2, the optical fiber 4 is used to transmit a detection light signal to the sensor chip 3 and receive a feedback light signal, the feedback light signal being at least used to characterize the pressure received by the sensor chip 3.

[0051] Specifically, the main body 1 can serve as a supporting structure for the entire pressure sensor 10 , providing a basis for the installation of other components (such as the first diaphragm 2 , the sensor chip 3 , etc.) and the conduction of pressure.

[0052] Furthermore, the main body 1 has a first side 11 and a second side 12 opposite to each other, and has a hollow portion 13 inside thereof communicating with the first side 11 and the second side 12 .

[0053] Furthermore, the first diaphragm 2 is connected to the first side 11 of the main body 1 and seals the opening of the hollow portion 13 on the first side 11. The first diaphragm 2 is the initial interface between the pressure sensor 10 and the external pressure. When external pressure acts on the first diaphragm 2, it deforms. This deformation is a key initial step in subsequent pressure transmission and detection.

[0054] Furthermore, the sensor chip 3 is connected to the second side 12 of the main body 1 and seals the opening of the hollow portion 13 on the second side 12. That is, the first diaphragm 2 and the sensor chip 3 seal the openings of the hollow portion 13 on the first side 11 and the second side 12, respectively, so that the hollow portion 13 is sealed.

[0055] Furthermore, the hollow portion 13 is filled with a pressure transmission medium, and the pressure transmission medium can be used to uniformly transmit the pressure received by the first diaphragm 2 to the sensor chip 3 .

[0056] Since the pressure transmission medium has a hydrostatic characteristic, the measurement error caused by the local deformation of the first diaphragm 2 can be effectively eliminated through the conduction of the pressure transmission medium, so that the pressure can be transmitted to the sensor chip 3 more accurately and stably.

[0057] Furthermore, after receiving the pressure transmitted through the pressure-transmitting medium, the sensor chip 3 will produce corresponding physical changes (such as changes in certain optical or electrical properties), and these changes are related to the magnitude of the received pressure.

[0058] Furthermore, optical fiber 4 can be disposed on a side of sensor chip 3 facing away from first diaphragm 2. Optical fiber 4 is used to transmit a detection light signal to sensor chip 3. The detection light signal is an optical signal used to detect the state of sensor chip 3. When the detection light signal interacts with sensor chip 3, it undergoes a specific modulation based on changes in pressure on sensor chip 3.

[0059] At the same time, the optical fiber 4 is also responsible for receiving the feedback optical signal modulated by the sensor chip 3. The feedback optical signal carries the pressure information received by the sensor chip 3. By analyzing and processing the feedback optical signal, the pressure applied to the first diaphragm 2 can be determined.

[0060] In actual applications, when external pressure acts on the first diaphragm 2, it deforms, and the pressure is evenly transmitted to the sensor chip 3 through the pressure-transmitting medium in the hollow portion 13. The sensor chip 3 changes accordingly based on the received pressure. The detection light signal emitted by the optical fiber 4 interacts with the sensor chip 3 to form a feedback light signal. This feedback light signal is received by the optical fiber 4 and used to represent the pressure received by the sensor chip 3, thereby achieving pressure measurement.

[0061] As described above, the pressure sensor 10 effectively improves the accuracy of pressure measurement by introducing the pressure transmission medium, and the damping effect of the pressure transmission medium also significantly improves the stability of dynamic pressure measurement.

[0062] Furthermore, because the pressure-transmitting medium filled within the hollow portion 13 has a certain surface tension, this surface tension generates an additional force at the contact interface between the pressure-transmitting medium and the first diaphragm 2. When the first diaphragm 2 deforms under external pressure, the surface tension of the pressure-transmitting medium resists this deformation, thereby providing a certain degree of support for the first diaphragm 2 and increasing the rigidity of the first diaphragm 2 without affecting the transmission of pressure.

[0063] For example, when measuring high pressures, the first diaphragm 2 is subjected to significant forces, making it susceptible to excessive deformation or even damage. However, the surface tension of the pressure-transmitting medium can mitigate the direct effects of this pressure on the first diaphragm 2 to a certain extent, allowing the first diaphragm 2 to maintain a relatively stable state over a wider pressure range and avoid damage due to excessive deformation. This expands the measurement range of the pressure sensor 10, enabling it to measure relatively high pressures.

[0064] In some embodiments, a protective layer may be coated on the surface of the first diaphragm 2 facing away from the sensor chip 3 , thereby effectively extending the service life of the first diaphragm 2 .

[0065] In some embodiments, the pressure transmission medium can be silicone oil. Silicone oil has excellent fluidity and can evenly transmit pressure within hollow portion 13, ensuring that the pressure sensed by first diaphragm 2 is accurately transmitted to sensor chip 3. Silicone oil also has high chemical stability and is less likely to react chemically with other materials in pressure sensor 10, ensuring the long-term stability and reliability of pressure sensor 10. Furthermore, silicone oil has a moderate surface tension, providing support for first diaphragm 2 without compromising pressure transmission efficiency due to excessive surface tension.

[0066] In other embodiments, the pressure transmission medium may also be glycerin, fluorinated liquid, or other materials.

[0067] In some embodiments, the sensor chip 3 may be a Micro Opto-Mechanical Pressure (MOMP) chip, or MOMP chip for short. Its sensing principle is based on Fabry-Pérot Cavity (FP) interferometry. The MOMP chip is manufactured using semiconductor processing technology and is a passive sensor device.

[0068] In some embodiments, the sensor chip 3 may include: a base 31, attached to the second side 12; a second diaphragm 32, arranged on the base 31 and located between the base 31 and the hollow portion 13, a sealed cavity is formed between the base 31 and the second diaphragm 32, the second diaphragm 32 is suitable for generating corresponding deformation according to the pressure change of the pressure transmission medium in the hollow portion 13, and the feedback light signal carries the deformation information of the second diaphragm 32.

[0069] Specifically, the base 31 is attached to the second side 12 of the main body 1 , so that the base 31 can be firmly mounted on the main body 1 , providing a stable supporting platform for the entire sensor chip 3 .

[0070] In some embodiments, the surface of the second diaphragm 32 facing the optical fiber 4 can be coated with a total reflection film. In actual pressure measurement applications, the total reflection film can effectively reduce the impact of environmental factors on the optical signal, ensuring that the pressure sensor 10 can accurately measure pressure changes. In addition, due to the improved efficiency of optical signal transmission, the pressure sensor 10 can respond to pressure changes more quickly, achieving more real-time pressure monitoring. This is of great significance for applications that require a high response speed to pressure changes, such as tram pantograph pressure monitoring, industrial automation control, aerospace, and other fields.

[0071] Furthermore, the second diaphragm 32 is disposed on the base 31 and is located between the base 31 and the hollow portion 13. Thus, the second diaphragm 32 can directly contact the pressure transmission medium in the hollow portion 13, thereby sensing the pressure change of the pressure transmission medium.

[0072] Furthermore, a sealed cavity is formed between the base 31 and the second diaphragm 32. The sealed cavity can be used to form an FP cavity. The FP cavity has unique optical properties. When light propagates back and forth in the cavity, light that meets certain conditions will interfere.

[0073] When external pressure is transmitted to the second diaphragm 32 through the first diaphragm 2 and the pressure-transmitting medium, the pressure change in the pressure-transmitting medium causes the second diaphragm 32 to deform, thereby changing the length of the FP cavity. Furthermore, after the probe light signal emitted by the optical fiber 4 enters the FP cavity, the wavelength that satisfies the interference enhancement condition also changes due to the change in the FP cavity length. In other words, the intensity distribution of different wavelengths in the feedback light signal changes, and this change causes the feedback light signal to carry information about the deformation of the second diaphragm 32. By analyzing the feedback light signal, for example using spectral analysis techniques, the wavelength change that satisfies the interference enhancement condition can be determined. Based on the relationship between the FP cavity length and wavelength, the change in the FP cavity length can be calculated, ultimately determining the magnitude of the external pressure. Therefore, the optical properties of the FP cavity enable it to convert small pressure changes into significant changes in the light signal, thereby improving the accuracy of pressure measurement. Furthermore, the structure is relatively simple, making it easy to integrate and manufacture.

[0074] In some embodiments, the second diaphragm 32 is at least partially exposed at the opening of the hollow portion 13 toward the second side 12. The at least partially exposed second diaphragm 32 ensures that the pressure of the pressure-transmitting medium is fully transmitted to the second diaphragm 32. The deformation of the second diaphragm 32 can more accurately reflect the magnitude of the external pressure, thereby improving the accuracy of pressure measurement.

[0075] In some embodiments, the hollow portion 13 includes a first cavity 131 and a second cavity 132 that are interconnected, wherein the first cavity 131 is closer to the first diaphragm 2 than the second cavity 132 , and the first cavity 131 and the second cavity 132 are connected via a first through hole 133 .

[0076] In some embodiments, the bottom wall of the main body 1 forming the first cavity 131 can also be used to limit the maximum deformation of the first diaphragm 1 to prevent the measured pressure from being too high or a sudden pressure change from damaging the first diaphragm 2 and the sensor chip 3 .

[0077] In some embodiments, continue to refer to Figure 7 The hollow portion 13 includes a first cavity 131 and a second cavity 132 that are interconnected, wherein the first cavity 131 is closer to the first diaphragm 2 than the second cavity 132, and the first cavity 131 and the second cavity 132 are connected through a first through hole 133.

[0078] Specifically, the hollow portion 13 is divided into a first cavity 131 and a second cavity 132 that are interconnected. The first cavity 131 and the second cavity 132 are connected via a first through hole 133. The presence of the first through hole 133 ensures that the pressure transmission medium between the two cavities can flow mutually, thereby achieving pressure transmission.

[0079] In actual applications, when external pressure acts on the first diaphragm 2, the first diaphragm 2 deforms, and the pressure is first transmitted to the pressure-transmitting medium in the first cavity 131. The first cavity 131 can be considered a preliminary pressure buffer area, which can absorb and disperse the pressure shock, making the pressure transmission more stable. Then, at least a portion of the pressure-transmitting medium originally located in the first cavity 131 flows into the second cavity 132 through the first through hole 133, further transmitting the pressure to the pressure-transmitting medium in the second cavity 132, and ultimately acting on the second diaphragm 32. This staged pressure transmission method helps reduce the impact of sudden pressure changes on the sensor chip 3 and improve the stability and reliability of the pressure sensor 10.

[0080] In some embodiments, along a direction perpendicular to the first side 11 and pointing toward the second side 12 , the cross-sectional area of ​​the first cavity 131 may be larger than the cross-sectional area of ​​the second cavity 132 . This can reduce the pressure per unit area, which is beneficial for protecting the sensor chip 3 .

[0081] Furthermore, the cross-sectional area of ​​the first cavity 131 is adapted to the surface area of ​​the first diaphragm 2. Therefore, the larger cross-sectional area of ​​the first cavity 131 can increase the surface area of ​​the first diaphragm 2, thereby increasing its force-bearing surface. As a result, the first diaphragm 2 can more fully sense changes in external pressure. For example, when measuring pressure distribution over a larger area, the larger first diaphragm 2 can cover a wider area, thereby more accurately reflecting the pressure distribution in that area, improving the applicability and accuracy of the pressure sensor 10 for large-area pressure measurement.

[0082] Furthermore, the cross-sectional area of ​​the second cavity 132 is adapted to the exposed area of ​​the second diaphragm 32. This prevents pressure loss during transmission. For example, if the cross-sectional area of ​​the second cavity 132 is too large, the pressure-transmitting medium may be excessively dispersed within the second cavity 132, causing pressure to be attenuated when transmitted to the second diaphragm 32, affecting the accuracy of pressure measurement.

[0083] In some embodiments, the cross-sectional area of ​​the first through-hole 133 is smaller than that of the second cavity 132, forming a stepped structure 134 at the junction of the first through-hole 133 and the second cavity 132. A first sealing structure 5 is disposed between the stepped structure 134 and the sensor chip 3. In the direction from the first side 11 to the second side 12, the first sealing structure 5 avoids the first diaphragm 2. Thus, the first sealing structure 5 effectively prevents leakage of the pressure-transmitting medium, ensuring that the pressure-transmitting medium within the hollow portion 13 remains stable, thereby ensuring accurate pressure measurement. Furthermore, in the direction from the first side 11 to the second side 12, the first sealing structure 5 avoids the first diaphragm 2, preventing it from interfering with the normal operation of the first diaphragm 2.

[0084] In some embodiments, the second side 12 of the main body 1 further defines a mounting groove 14 for accommodating at least a portion of the sensor chip 3. The mounting groove 14 communicates with the second cavity 132. This allows the sensor chip 3 to be more stably mounted on the second side 12 of the main body 1. Furthermore, the embedded mounting arrangement of the sensor chip 3 makes the internal structure of the pressure sensor 10 more compact, improving space utilization.

[0085] In some embodiments, the main body 1 is further provided with a second through hole 15, which is connected to the hollow portion 13, and the second through hole 15 is used to inject a pressure transmission medium into the hollow portion 13. The pressure sensor 10 may also include: a sealing plug 16, which is used to close the second through hole 15. Therefore, in actual applications, the pressure sensor 10 may require regular maintenance or replacement of the pressure transmission medium. The presence of the second through hole 15 allows maintenance personnel to easily operate the pressure transmission medium in the hollow portion 13 through the second through hole 15, such as replenishing or replacing it. This greatly improves the maintainability of the pressure sensor 10 and extends its service life. Furthermore, the sealing plug 16 can close the second through hole 15 to prevent the pressure transmission medium from leaking from the second through hole 15.

[0086] In some embodiments, the pressure sensor 10 may further include: a base 6 connected to the second side 12, the sensor chip 3 is located between the base 6 and the main body 1, the base 6 is provided with a third through hole 61 extending in a direction from the first side 11 to the second side 12, and the optical fiber 4 transmits the detection light signal to the sensor chip 3 and receives the feedback light signal through the third through hole 61.

[0087] Specifically, the base 6 is connected to the second side 12 of the main body 1, and the sensor chip 3 is located between the base 6 and the main body 1. Thus, the clamping effect of the main body 1 and the base 6 can ensure that the sensor chip 3 is correctly positioned in the pressure sensor 10.

[0088] Furthermore, the third through hole 61 extends from the first side 11 toward the second side 12. The optical fiber 4 transmits a detection light signal to the sensor chip 3 and receives a feedback light signal through this through hole. This allows the optical fiber 4 to transmit light signals to the sensor chip 3 in the most direct and efficient manner, reducing light signal loss and interference during transmission. Furthermore, the extension direction of the third through hole 61 ensures that the light signal accurately reaches the sensor chip 3, improving the transmission efficiency and accuracy of the light signal.

[0089] In some embodiments, at least a portion of the optical fiber 4 is inserted into the third through hole 61, and the outer circumference of the optical fiber 4 is directly or indirectly connected to the inner wall of the third through hole 61. Thus, the third through hole 61 provides a relatively stable passage for the optical fiber 4, protecting it from external physical damage. During installation and use of the pressure sensor 10, the optical fiber 4 may be subjected to external forces such as stretching, bending, and squeezing. The third through hole 61 provides support and protection for the optical fiber 4, reducing the risk of damage and extending its service life.

[0090] In some embodiments, the signal emitting end of the optical fiber 4, that is, the end facing the third through hole 61, may be connected to a ceramic ferrule, which can be inserted into the third through hole 61. Thus, the ceramic ferrule can protect the signal emitting end of the optical fiber 4.

[0091] In some embodiments, the pressure sensor 10 may further include an optical collimator 7, which at least partially extends into the third through hole 61 and is optically coupled to one end of the optical fiber 4 facing the sensor chip 3. The optical collimator 7 is used to collimate the optical signal transmitted by the optical fiber 4. The optical signal output by the optical fiber 4 usually has a certain divergence angle. If it is directly irradiated onto the sensor chip 3, it will cause the optical signal to be unevenly distributed on the sensor chip 3, affecting the measurement accuracy. The optical collimator 7 can convert the divergent optical signal into a parallel optical signal, so that the optical signal can be more accurately irradiated onto a specific area of ​​the sensor chip 3, thereby improving the utilization efficiency of the optical signal and the accuracy of the measurement. Therefore, by optically coupling with the optical fiber 4, the optical collimator 7 can reduce the coupling loss of the optical signal between the optical fiber 4 and the sensor chip 3.

[0092] In some embodiments, the optical fiber 4 or the optical collimator 7 may be connected to the inner wall of the third through hole 61 by gluing, welding, or the like.

[0093] In some embodiments, combined Figure 7 The base 6 further includes: a flat plate portion 62 , which is in contact with the main body 1 ; an extension portion 63 , which extends from the flat plate portion 62 in a direction away from the sensor chip 3 , and the third through hole 61 is formed in the extension portion 63 and passes through the flat plate portion 62 .

[0094] In some embodiments, the outer contour of extension 63 can be configured as an optical connector. Accordingly, the end of optical fiber 4 facing sensor chip 3 can be connected to an optical connector that matches the outer contour of extension 63. This allows for simple insertion and alignment of optical fiber 4, improving ease of use.

[0095] In some embodiments, the optical connector may be, for example, an FC, LC, LS or other common optical connectors.

[0096] In some embodiments, a second sealing structure 8 is provided between the base 6 and the main body 1, and the second sealing structure 8 is provided around the third through hole 61. This ensures the sealing inside the pressure sensor 10 and achieves dustproof and waterproof functions.

[0097] In some embodiments, the pressure sensor 10 may further include a temperature compensation mechanism. The temperature compensation mechanism may be, for example, a grating structure provided at the signal transmitting end of the optical fiber 4. Alternatively, the temperature compensation mechanism may be formed by the base 31 of the sensor chip 3.

[0098] As described above, the technical solution of this application, compared to conventional pressure sensors that typically rely on direct modulation of optical signals by a pressure-sensitive membrane, whose sensitivity is susceptible to diaphragm deformation uniformity and installation stress, and requires repeated optical path calibration, introduces a pressure-transmitting medium as the pressure transmission medium. This utilizes the hydrostatic pressure characteristics of the fluid to uniformly transmit the force exerted on the diaphragm (e.g., first diaphragm 2) to the sensor chip 3, effectively eliminating measurement errors caused by localized diaphragm deformation in conventional structures and improving the measurement accuracy of pressure sensor 10. Furthermore, the damping effect of the pressure-transmitting medium significantly enhances the stability of dynamic pressure measurements.

[0099] Furthermore, the pressure sensor 10 includes a base 6 connected to the second side 12 of the main body 1. The base 6 defines a third through hole 61. The optical fiber 4 transmits the detection light signal to the sensor chip 3 and receives the feedback light signal through the third through hole 61. This ensures more stable transmission of the detection light signal and the feedback light signal between the sensor chip 3 and the optical fiber 4.

[0100] Furthermore, the sealed packaging of the entire pressure sensor 10 can be achieved through the first sealing structure 5 and the second sealing structure 8 , which has a simple structure and is easy to process, thereby helping to reduce production costs.

[0101] In some embodiments, combined Figures 1 to 3The contact force sensing device 100 may further include: a shell 20 having a accommodating cavity 201; the above-mentioned pressure sensor 10, wherein the shell 20 is provided with an assembly hole 202 to expose at least the first side 11 of the pressure sensor 10, and at least the second side 12 of the pressure sensor 10 is located in the accommodating cavity 201; a force guiding mechanism 30, connected to the shell 20 and having a first end 301 and a second end 302 relative to each other, the first end 301 contacts the first diaphragm 2, and the second end 302 directly or indirectly contacts the object to be measured to transmit the contact force exerted on the object to be measured to the first diaphragm 2.

[0102] Specifically, the housing 20 may include a body 204 and a bottom plate 205 .

[0103] In some embodiments, the body 204 and the bottom plate 205 together form the accommodating cavity 201. Furthermore, a fourth sealing structure 207 may be provided at the connection between the body 204 and the bottom plate 205 to ensure the sealing of the accommodating cavity 201, thereby achieving waterproof and dustproof functions.

[0104] In some embodiments, the outer surface of the base plate 205 facing away from the accommodating cavity 201 may be covered with a cover plate 206 to cover the fixing parts (such as screws, etc.) used to fix the base plate 205 and the body 204, thereby improving the overall appearance of the contact force sensing device 100.

[0105] In some embodiments, the housing 20 defines an assembly hole 202 to expose at least the first side 11 of the pressure sensor 10. This allows the first side 11 of the pressure sensor 10 to effectively contact and conduct force with the external environment or the force-guiding mechanism 30. Furthermore, at least the second side 12 of the pressure sensor 10 is located within the accommodating cavity 201, further ensuring the stability and safety of the pressure sensor 10.

[0106] In some embodiments, the outer surface of the portion of the main body 1 of the pressure sensor 10 near the first side 11 can be tightly attached to and stably connected to the inner wall of the assembly hole 202. For example, both the outer surface of the portion of the main body 1 near the first side 11 and the inner wall of the assembly hole 202 can be provided with threaded structures, and the pressure sensor 10 and the housing 20 can be connected through threaded engagement.

[0107] In some embodiments, the second side 12 of the main body 1 may further be provided with an extension portion 17 extending from the second side 12 of the main body 1 in a direction away from the central axis of the main body 1 .

[0108] In some embodiments, the extension portion 17 is annular and is used to fit against the inner wall of the housing 20 where the assembly hole 202 is formed, so as to further improve the tightness of the connection between the pressure sensor 10 and the housing 20 .

[0109] In some embodiments, a third sealing structure 80 may be further provided between the extension portion 17 and the inner surface of the housing 20 to ensure a sealed connection between the pressure sensor 10 and the housing 20 .

[0110] In some embodiments, combined Figure 2 and Figure 3 The housing 20 is further provided with a plug hole 203 , and the end of the optical fiber 4 facing away from the sensor chip 3 is directly or indirectly optically coupled to an optoelectronic device (not shown) through the plug hole 203 .

[0111] In some embodiments, the plug hole 203 can be opened on the side wall of the housing 20 .

[0112] In some embodiments, the contact force sensing device 100 may further include a coupler 40 , one end of which is optically coupled to the optical fiber 4 along its extension direction, and the other end of which is exposed to the plug-in hole 203 and removably connected to the optoelectronic device. This enables a "plug-and-play" application of the contact force sensing device 100 , facilitating installation and improving monitoring accuracy. Furthermore, accurate contact force monitoring ensures timely repair and maintenance of the object being measured.

[0113] In some embodiments, the contact force sensing device 100 may further include a socket structure 50. At least a portion of the socket structure 50 is inserted into the insertion hole 203, and the end of the coupler 40 facing away from the optical fiber 4 is fixed to the insertion channel 501 formed by the socket structure 50. Thus, the optoelectronic device can be connected to the socket structure 50 to connect with the coupler 40, thereby forming a complete and precisely connected optical path, making the contact force sensing device 100 more convenient to use.

[0114] In some embodiments, a detachable cover 60 may be provided at one end of the socket structure 50 for plugging into an optoelectronic device. When not in use, the cover 60 closes the plugging channel 501 to prevent dust and water.

[0115] In some embodiments, combined Figure 1 、 Figure 2 and Figure 4, the force-guiding mechanism 30 is connected to the housing 20 and has a first end 301 and a second end 302 relative to each other. The first end 301 contacts the first diaphragm 2 of the pressure sensor 10, and the second end 302 contacts the object to be measured directly or indirectly. Thus, the force-guiding mechanism 30 can effectively transmit the contact force exerted on the object to be measured to the first diaphragm 2 of the pressure sensor 10. When the object to be measured is subjected to contact force, the force is transmitted to the first end 301 through the second end 302 of the force-guiding mechanism 30, and then acts on the first diaphragm 2 of the pressure sensor 10 through the first end 301. The first diaphragm 2 is deformed under the action of the contact force, thereby causing a series of physical changes inside the pressure sensor 10, and finally converting the contact force into a measurable signal. The design of the force-guiding mechanism 30 ensures the accuracy and stability of force conduction, and reduces the loss and deviation of force during the conduction process.

[0116] Furthermore, the force-guiding mechanism 30 may include: a sleeve portion 303, having a third end 3031 and a fourth end 3032 relative to each other along the extension direction, the third end 3031 being connected to the pressure sensor 10, the sleeve portion 303 having an accommodating channel 3033, docked with and connected to the assembly hole 202; a pressure block portion 304, accommodated in the accommodating channel 3033 and in contact with the first diaphragm 2; a spring structure 305, accommodated in the accommodating channel 3033, and located on the side of the pressure block portion 304 away from the first diaphragm 2, the spring structure 305 is deformed under the pressure of the object to be measured, and transmits the reaction force generated by the deformation to the first diaphragm 2.

[0117] Specifically, the sleeve portion 303 has a third end 3031 and a fourth end 3032 that are opposite to each other along the extension direction, wherein the third end 3031 is connected to the pressure sensor 10 to ensure a stable connection between the force guiding mechanism 30 and the pressure sensor 10, so that force can be accurately transmitted from the force guiding mechanism 30 to the pressure sensor 10. At the same time, the sleeve portion 303 also provides a stable accommodation space for other components (such as the pressure block portion 304 and the spring structure 305), ensuring the compactness and stability of the entire force guiding mechanism 30.

[0118] Furthermore, the sleeve portion 303 has an accommodating channel 3033, which interfaces with and communicates with the assembly hole 202 of the housing 20. The accommodating channel 3033 provides space for the pressure block portion 304 and the spring structure 305 to move. The connection between the accommodating channel 3033 and the assembly hole 202 ensures that external force can be smoothly transmitted to the first diaphragm 2 of the pressure sensor 10 through the force guiding mechanism 30.

[0119] Furthermore, the pressing block 304 is accommodated in the accommodating channel 3033 and contacts the first diaphragm 2. When the object to be measured is subjected to a contact force, the force is transmitted to the pressing block 304 through other parts of the force guiding mechanism 30. The pressing block 304 then directly applies the force to the first diaphragm 2, causing the first diaphragm 2 to deform.

[0120] Furthermore, the spring structure 305 is housed within the accommodating channel 3033 and is located on the side of the pressure block portion 304 facing away from the first diaphragm 2. Under the pressure of the object to be measured, the spring structure 305 deforms, and the reaction force generated by this deformation is transmitted to the first diaphragm 2. The presence of the spring structure 305 also improves the measurement stability of the contact force sensing device 100. During the measurement process, the spring structure 305 reduces measurement errors caused by external vibrations and impacts, ensuring the accuracy and reliability of the measurement results.

[0121] In addition, the spring structure 305 can disperse the contact force into a uniformly distributed load through its elastic deformation. If a traditional rigid connection is used, local stress concentration may directly impact the first diaphragm 2, causing the first diaphragm 2 to be locally subjected to excessive force, which can be easily damaged and cause inaccurate measurements. The spring structure 305's load dispersion effectively avoids the direct impact of local stress concentration on the first diaphragm 2. Furthermore, the compression (displacement) of the spring structure 305 and the conductive force (i.e., the contact force) are nonlinearly related (Hooke's law). The object to be measured may produce a large displacement under the action of the contact force, while the actual force borne by the pressure sensor 10 is smoothly transmitted, preventing the pressure sensor 10 from being overloaded due to sudden changes in displacement.

[0122] In some embodiments, a buffer structure 306 is provided on the side of the pressure block portion 304 facing the first diaphragm 2. This can enhance the protection of the first diaphragm 2, improve the stability and accuracy of the measurement, optimize the force transmission process, and reduce the adverse effects caused by direct impact and stress concentration.

[0123] In some embodiments, the area of ​​the end surface of the pressure block portion 304 facing the pressure sensor 10 may be larger than the area of ​​the end surface of the buffer structure 306 facing the pressure sensor 10. The first side 11 of the pressure sensor 10 may also be provided with a support ring 70, which is arranged around the first diaphragm 2. The buffer structure 306 may pass through the support ring 70 and contact the first diaphragm 2. The support ring 70 may also be used to limit the maximum displacement of the pressure block portion 304. When the pressure block portion 304 moves toward the pressure sensor 10 at a relatively fast speed, the pressure block portion 304 will first abut against the support ring 70, thereby limiting the further displacement of the buffer structure 306, thereby preventing excessive displacement from impacting the first diaphragm 2 and causing damage to the first diaphragm 2.

[0124] In some embodiments, the force-guiding mechanism 30 may further include: a pressure cover portion 307, which is accommodated in the accommodating channel 3033 and covers at least a portion of the spring structure 305 on a side away from the pressure block portion 304. The pressure cover portion 307 is suitable for connecting with the object to be measured, and as the object to be measured moves under pressure, the pressure cover portion 307 reciprocates along the accommodating channel 3033.

[0125] In some embodiments, reference Figure 8 The contact force sensing device 100 can be used to monitor the contact force applied to a pantograph, wherein the pantograph includes a spring box 200, and the spring box 200 includes: a shell 2001, with a telescopic portion 2002 built therein, the telescopic portion 2002 extending or retracting into the shell 20 under the action of the pressure applied to the pantograph, the shell 2001 and the sleeve portion 303 are fixedly connected, the telescopic portion 2002 and the pressure cover portion 307 are fixedly connected, and the pressure cover portion 307 reciprocates along the accommodating channel 3033 as the telescopic portion 2002 moves.

[0126] Specifically, the contact force may, for example, include the force exerted by the wire when the pantograph contacts the wire (or catenary).

[0127] When the pantograph is subjected to a contact force, the telescopic portion 2002 will extend or retract into the housing 20 under the action of the contact force. Since the telescopic portion 2002 and the pressure cover portion 307 are fixedly connected, the pressure cover portion 307 will reciprocate along the accommodating channel 3033 as the telescopic portion 2002 moves. The movement of the pressure cover portion 307 compresses or stretches the spring structure 305. The spring structure 305 transmits force to the pressure block portion 304 through elastic deformation. The pressure block portion 304 then applies force to the first diaphragm 2, causing the first diaphragm 2 to deform. The deformation of the first diaphragm 2 is converted into an electrical signal output by the pressure sensor 10, thereby realizing the monitoring of the contact force applied to the pantograph.

[0128] Continue to refer Figure 8 The object to be measured may further include a bracket 300 , wherein the bracket 300 and the housing 2001 of the spring box 200 are fixedly connected via a connecting portion 400 and a sleeve portion 303 of the force guiding mechanism 30 .

[0129] In practical applications, a single pantograph may have four Figure 8 The spring box 200 shown in FIG. Accordingly, each spring box 200 can be connected to a contact force sensing device 100. Thus, the contact forces at different positions of the pantograph can be fully monitored.

[0130] Therefore, the contact force sensing device 100 can be installed on the spring box 200 through the connecting portion 400 without changing the original structure of the pantograph, thereby accurately monitoring the contact force between the pantograph and the wire.

[0131] In a typical application scenario, when the pantograph's bow (the component used to contact the wires) rises and contacts the wires, a certain contact force is generated between the pantograph and the wires. This contact force, in turn, causes the spring center axis (i.e., telescopic portion 2002) within the pantograph's spring box to move downward, resulting in a corresponding displacement. Because the pressure-conducting portion 307 within the force-conducting mechanism 30 is fixedly connected to the telescopic portion 2002, the pressure-conducting portion 307 also moves accordingly, compressing the spring structure 305 within the force-conducting mechanism 30. The compression of the spring structure 305 then transmits force to the first diaphragm 2 of the pressure sensor 10. Under the force, the first diaphragm 2 deforms toward the interior of the hollow portion 13, causing changes in the closed hollow portion 13 cavity. The force transmitted by the pressure-transmitting medium causes the second diaphragm 32 of the sensor chip 3 to deform and displace, thereby calculating the contact force. (The sensing mechanism of the FP cavity is not further described here.)

[0132] Under ideal conditions, the contact force between the pantograph and the wire is calculated as follows:

[0133] Formula 1: ;

[0134] in, is the contact force between the pantograph and the wire, It is a part of the contact force between the pantograph and the catenary that a single spring box 200 receives. is another part of the contact force between the pantograph and the catenary measured by the contact force sensing device 100 hung under the single spring box 200. is the force value measured at the support of a single spring box 200, is the number of support points of the spring box 200.

[0135] There are also:

[0136] Formula 2: ;

[0137] is the elastic coefficient of the spring inside the spring box 200, is the compression amount of the spring inside the spring box 200, that is, the displacement of the telescopic part 2002.

[0138] There are also:

[0139] Formula 3: ;

[0140] is the elastic coefficient of the spring structure 305, is the compression amount of the spring structure 305, that is, the displacement amount of the gland portion 307, The pressure sensor 10 senses the The pressure value measured after the force is applied, that is, the change in the pressure of the pressure medium inside the hollow part 13 obtained by the sensor chip 3, is the effective bearing area of ​​the first diaphragm 2.

[0141] Since the pressure cover portion 307 and the telescopic portion 2002 in the force guiding mechanism 30 are fixedly connected, the springs at these two locations have a common compression stroke, namely:

[0142] Formula 4: ;

[0143] Combining formulas 1-4, we have:

[0144] .

[0145] As described above, the contact force sensing device 100 of the present embodiment forms a closed-loop "pressure-deformation-reaction force" transmission chain through the coordinated action of the sleeve portion 303, the pressure block portion 304, and the spring structure 305. The nonlinear compression characteristics of the spring structure 305 automatically compensate for contact surface irregularities, making the pressure distribution more uniform, reducing the risk of localized stress concentration, and improving measurement consistency. In practical applications, when the object to be measured is compressed and displaced, the pressure cap portion 307 pushes the spring structure 305 to deform. The spring structure 305 elastically deforms to disperse the concentrated force into a uniformly distributed load, preventing localized stress concentration in traditional rigid connections from directly impacting the diaphragm of the pressure sensor 10 (e.g., the first diaphragm 2). Furthermore, the compression (displacement) of the spring structure 305 and the transmission force are nonlinearly related (Hooke's law). While the object to be measured may experience significant displacement under the action of the contact force, the actual force borne by the pressure sensor 10 is smoothly transmitted, preventing overload of the pressure sensor 10 due to sudden displacement changes.

[0146] Furthermore, through the provision of the plug hole 203 and the coupler 40 , optoelectronic devices (such as grating demodulators) can be plug-and-play through the coupler 40 , thereby reducing on-site debugging costs.

[0147] It should be understood that the term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " herein indicates that the objects associated before and after are in an "or" relationship. As used herein, unless otherwise expressly stated, the term "or" covers all possible combinations unless not feasible. For example, if a component is stated to include A or B, then unless otherwise expressly stated or not feasible, the component may include A, or B, or A and B. As a second example, if a component is stated to include A, B, or C, then unless otherwise expressly stated or not feasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. The "multiple" appearing in the embodiments of the present application refers to two or more.

[0148] The relational terms appearing in the embodiments of the present application, such as first, second, etc. descriptions, are only used to distinguish an entity or operation from another entity or operation, and do not require or imply any actual relationship or order between these entities or operations. In addition, the words "comprise", "have" and "include" and other similar forms are intended to be equivalent in meaning and are open-ended, and one or more items following any of these words do not mean an exhaustive list of such one or more items, or mean to be limited to the one or more items listed. In the drawings and the specification, exemplary embodiments have been disclosed. However, many changes and modifications can be made to these embodiments. Therefore, although specific terms have been adopted, they are only used in a general and descriptive sense, not for the purpose of limitation.

[0149] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A pressure sensor, characterized in that: include: A main body portion having a first side and a second side opposite to each other, the main body portion having a hollow portion communicating with the first side and the second side; a first diaphragm connected to the first side and closing the opening of the hollow portion located on the first side; a sensor chip connected to the second side and closing the opening of the hollow portion located on the second side, the hollow portion being filled with a pressure transmission medium to transmit the pressure received by the first diaphragm to the sensor chip; An optical fiber is arranged on a side of the sensor chip away from the first diaphragm, and is used to transmit a detection light signal to the sensor chip and receive a feedback light signal, wherein the feedback light signal is at least used to represent the pressure received by the sensor chip.

2. The pressure sensor according to claim 1, wherein The sensor chip comprises: a base, attached to the second side; The second diaphragm is arranged on the base and located between the base and the hollow part. A sealed cavity is formed between the base and the second diaphragm. The second diaphragm is suitable for generating corresponding deformation according to the pressure change of the pressure transmission medium in the hollow part. The feedback light signal carries the deformation information of the second diaphragm.

3. The pressure sensor according to claim 2, wherein: The second membrane is at least partially exposed at an opening of the hollow portion toward the second side.

4. The pressure sensor according to claim 1, wherein The hollow portion includes a first cavity and a second cavity that are connected to each other, wherein the first cavity is closer to the first diaphragm than the second cavity, and the first cavity and the second cavity are connected through a first through hole.

5. The pressure sensor according to claim 4, characterized in that The cross-sectional area of ​​the first through hole is smaller than the cross-sectional area of ​​the second cavity to form a step structure at the connection between the first through hole and the second cavity, and a first sealing structure is provided between the step structure and the sensor chip, wherein the first sealing structure avoids the first diaphragm in the direction from the first side to the second side.

6. The pressure sensor according to claim 4, characterized in that A mounting groove is further formed on the second side of the main body for accommodating at least a portion of the sensor chip, and the mounting groove is communicated with the second cavity.

7. The pressure sensor according to claim 1, wherein The main body is further provided with a second through hole communicating with the hollow portion, wherein the second through hole is used for injecting a pressure transmission medium into the hollow portion, and further comprises: a sealing plug for closing the second through hole.

8. The pressure sensor according to claim 1, wherein Also includes: A base is connected to the second side, the sensor chip is located between the base and the main body, the base is provided with a third through hole extending from the first side to the second side, and the optical fiber transmits the detection light signal to the sensor chip and receives the feedback light signal through the third through hole.

9. The pressure sensor according to claim 8, characterized in that At least a portion of the optical fiber is inserted into the third through hole, and an outer peripheral surface of the optical fiber is directly or indirectly connected to an inner wall of the third through hole.

10. The pressure sensor according to claim 8, wherein Also includes: An optical collimator at least partially extends into the third through hole and is optically coupled to an end of the optical fiber facing the sensor chip.

11. The pressure sensor according to claim 8, characterized in that A second sealing structure is provided between the base and the main body, and the second sealing structure is provided around the third through hole.

12. A contact force sensing device, characterized in that: include: A housing having a receiving cavity; The pressure sensor according to any one of claims 1 to 11, wherein the housing is provided with an assembly hole to expose at least a first side of the pressure sensor, and at least a second side of the pressure sensor is located in the accommodating cavity; The force guiding mechanism is connected to the housing and has a first end and a second end opposite to each other, wherein the first end contacts the first diaphragm, and the second end directly or indirectly contacts the object to be measured to conduct the contact force exerted on the object to be measured to the first diaphragm.

13. The contact force sensing device according to claim 12, wherein: The housing is further provided with a plug hole, and the end of the optical fiber facing away from the sensor chip is directly or indirectly optically coupled to a photoelectric device through the plug hole.

14. The contact force sensing device according to claim 13, wherein: Also includes: A coupler, along the extension direction, one end of the coupler is optically coupled to the optical fiber, and the other end of the coupler is exposed to the plug hole and is pluggably connected to the optoelectronic device.

15. The contact force sensing device according to claim 12, wherein: The force guiding mechanism comprises: a sleeve portion having a third end and a fourth end opposite to each other along an extension direction, wherein the third end is connected to the pressure sensor, and the sleeve portion has an accommodating channel that is docked with and communicated with the assembly hole; a pressing block portion, accommodated in the accommodating channel and in contact with the first diaphragm; A spring structure is accommodated in the accommodating channel and is located on a side of the pressure block portion away from the first diaphragm. The spring structure deforms under the pressure of the object to be measured and transmits the reaction force generated by the deformation to the first diaphragm.

16. The contact force sensing device according to claim 15, wherein: A buffer structure is provided on a side of the pressing block portion facing the first diaphragm.

17. The contact force sensing device according to claim 15, wherein: Also includes: The pressure cover portion is accommodated in the accommodating channel and covers at least a portion of the spring structure on a side away from the pressure block portion. The pressure cover portion is suitable for connecting with the object to be measured. As the object to be measured moves under pressure, the pressure cover portion reciprocates along the accommodating channel.

18. The contact force sensing device according to claim 17, wherein: The contact force sensing device is used to monitor the contact force applied to the pantograph, wherein the pantograph includes a spring box, and the spring box includes: a shell with a built-in telescopic part, and the telescopic part extends or retracts into the shell under the action of the contact force applied to the pantograph, the shell and the sleeve part are fixedly connected, the telescopic part and the pressure cover part are fixedly connected, and the pressure cover part reciprocates along the accommodating channel with the movement of the telescopic part.

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