Compression-resistant gasket structure based on pore structure and manufacturing method of compression-resistant gasket structure
By setting recessed holes on the gasket body and filling them with sensitive material, the problem of easy damage to the plate capacitor structure is solved, achieving high-precision and stable pressure sensing function and extending the service life of the gasket.
Patent Information
- Application Number
- CN202511026590.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-11-04
AI Technical Summary
In existing pressure-resistant gasket technology, the mechanical strength of the plate capacitor structure is insufficient, which makes the gasket prone to plastic deformation or breakage during use. Furthermore, external environmental factors accelerate the performance degradation of the gasket, affecting the force measurement accuracy and stability.
The pressure-resistant gasket design based on a porous structure is adopted. By setting concave holes in the main body of the gasket and filling them with sensitive material, combined with sensing circuits and antennas, the deformation of the sensitive material generates electrical signals. The sensing circuits and antennas perform signal processing and transmission. The protective layer wraps the sensor to avoid direct pressure.
It improves the service life and force measurement accuracy of the gasket, isolates the sensor components from external environmental corrosion, ensures that the gasket does not fail in extreme environments, and achieves stable pressure sensing function.
Smart Images
Figure CN120890583A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pressure-resistant gaskets, and more specifically to a pressure-resistant gasket structure based on a porous structure and its manufacturing method. Background Technology
[0002] In existing pressure-resistant gasket technologies, simple layered structures are often used for applications involving polymer materials. Some pressure-sensing gaskets directly use the polymer material as the load-bearing layer, simply covered by a rubber layer without constructing an effective protective system, resulting in direct pressure damage to the polymer material. Other multi-layered gaskets, while combining various materials, lack optimized pressure transmission paths between layers, failing to ensure uniform stress distribution on the polymer material. From a functional perspective, existing technologies do not deeply integrate the pressure-resistant structure with the principle of capacitance change. Because the gaskets do not provide three-dimensional encapsulation of the polymer material, uneven pressure distribution and unstable capacitance signal output occur.
[0003] In existing pressure-measuring pad technologies, plate capacitance measurement is commonly used. This technology combines plate capacitors and dielectric materials into a conventional capacitor structure, which is then covered with an external polymer material and used directly as a force-measuring pad. Alternatively, the capacitor is embedded inside a metal pad, and pressure changes are measured by the displacement of the capacitor plates caused by the deformation of the metal under pressure. However, the principle of plate capacitance measurement reveals a flaw in this structure: In scenarios where the plate capacitor structure is directly used as a force measuring pad, the lack of sufficient mechanical strength for protection can lead to plastic deformation or direct breakage of the pad during use due to insufficient compressive strength, thus causing the pad to fail.
[0004] In scenarios where plate capacitors are embedded inside metal pads as force measuring pads, the placement of plate capacitors requires hollowing out the stress-bearing area of the metal pads. This reduces the structural strength of the metal pads. Under extreme conditions such as strong impacts on the target being measured, the metal pads may be subjected to pressure exceeding their limits, causing yielding deformation or breakage, ultimately leading to pad failure.
[0005] The process design flaws involve using the plate capacitor directly as a force measuring pad. In this process design, the pad lacks sufficient external protection. Temperature, humidity, ultraviolet radiation, acid and alkali contamination of the measured target will accelerate the aging of the pad, leading to performance degradation or failure. Summary of the Invention
[0006] To address the aforementioned shortcomings in the prior art, this invention provides a pressure-resistant gasket structure based on a porous structure and its manufacturing method, which solves the problem that existing gaskets using plate capacitors are prone to performance degradation or even failure.
[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: Provided is a compression-resistant gasket structure based on a pore structure, which comprises a gasket body, the side surface of the gasket body is provided with a protective layer, a sensing circuit and / or an antenna are arranged in the protective layer; a recess is arranged on the gasket body; the surface of the recess is provided with an insulating material, and the recess is filled with a sensitive material; The gasket body is used to bear external loads and generate controllable deformation to act on the sensitive material; The sensitive material generates a corresponding electrical signal in response to the deformation of the gasket body; The sensing circuit is electrically connected to the piezoelectric material and the antenna, respectively, and generates a sensing signal in response to the electrical signal generated by the sensitive material; The antenna is used to transmit the sensing signal generated by the sensing circuit outward.
[0008] Further, the recess is arranged on the upper surface of the gasket body, and the position of the recess satisfies the following conditions: Wherein is the position of the recess; is the inner diameter of the gasket body; is the outer diameter of the gasket body; is a constant greater than or equal to 0.3 and less than or equal to 0.7.
[0009] Further, The value of is greater than or equal to 0.45 and less than or equal to 0.55.
[0010] Further, the size of the recess satisfies the following conditions: Wherein is the size of the recess; is the aperture coefficient, is greater than or equal to 0.15 and less than or equal to 0.8; is the thickness of the gasket body; is the ring width of the gasket body.
[0011] Further, when the thickness of the gasket body is less than or equal to 1 mm, the recess is elliptical; when the thickness of the gasket body is greater than 1 mm and less than 10 mm, the recess is circular; and when the thickness of the gasket body is greater than or equal to 10 mm, the recess is a racetrack ring.
[0012] Further, the side surface of the gasket body is L-shaped, and the protective layer is located on the step formed by the L-shape and flush with the step.
[0013] Further, the opening of the recess is encapsulated with an encapsulation sheet made of the same material as the gasket body, and the contact part of the encapsulation sheet with the sensitive material is provided with an insulating coating.
[0014] A method for manufacturing a compression-resistant gasket structure based on a pore structure is provided, comprising the following steps: Determine the position, shape and size of the recess according to the size data of the gasket body and perform hole digging to form the recess; Perform insulation treatment on the surface of the recess; Cut the sensitive material according to the shape and size of the recess to obtain a sensitive material matching the recess; Grow measurement electrodes on both poles of the sensitive material, integrally encapsulate the sensitive material with the grown measurement electrodes and place them into the recess, and connect the measurement electrodes with the sensing circuit; Use an encapsulation sheet made of the same material as the gasket body to pre-stress encapsulate the sensitive material placed in the recess, so that the encapsulation sheet is in close contact with the sensitive material placed in the recess, and obtain a gasket encapsulated with the encapsulation sheet; Integrally perform insulation treatment on the gasket encapsulated with the encapsulation sheet to obtain an insulation-treated gasket; Place the insulation-treated gasket, the sensing circuit and the antenna into a mold, inject an injection molding material into the mold through an injection molding machine, so that the injection molding material covers the sensing circuit and / or the antenna to form a protective layer.
[0015] Further, when the gasket body is hole-dug, the stress concentration coefficient is controlled to be less than or equal to 1.3.
[0016] Further, the specific method for determining the position, shape and size of the recess according to the size data of the gasket body comprises: Determine the position of the recess according to the inner diameter and the outer diameter of the gasket body, and the corresponding expression is: Wherein is the position of the recess; is the inner diameter of the gasket body; is the outer diameter of the gasket body; is a constant greater than or equal to 0.3 and less than or equal to 0.7; Determine the size of the recess according to the thickness and the ring width of the gasket body, and the corresponding expression is: Wherein is the size of the recess; is the hole diameter coefficient, is greater than or equal to 0.15 and less than or equal to 0.8; is the thickness of the gasket body; is the ring width of the gasket body; Determine the shape of the recess according to the thickness of the gasket body: When the thickness of the gasket body is less than or equal to 1 millimeter, the recess is elliptical; When the thickness of the gasket body is greater than 1 mm and less than 10 mm, the recess hole is circular; When the thickness of the gasket body is greater than or equal to 10 mm, the recess hole is a track ring shape.
[0017] The present application has the following advantages: 1. The present application sets the sensitive material in the form of a recess hole, which has little influence on the mechanics of the gasket body, and the sensitive material does not directly participate in pressure bearing, so that the sensitive material, the sensing circuit and the antenna are not easily damaged, thereby improving the service life and ensuring the performance of the gasket.
[0018] 2. The present application determines the position, shape and size of the recess hole according to the size data of the gasket body, which can maximize the avoidance of the influence on the mechanics of the gasket body, while ensuring the sensing accuracy and service life of the present pressure-resistant gasket structure.
[0019] 3. The present application pre-stresses the sensitive material placed in the recess hole by the packaging sheet of the same material as the gasket body, which can ensure the height consistency of the two measuring electrodes of the sensitive material and the initial pre-stress value of each gasket structure, thereby better monitoring the pressure change. The pre-stress packaging can also seal the sensitive material and isolate the direct erosion of the external environment on the sensitive material.
[0020] 4. The present application insulates the gasket as a whole after packaging the packaging sheet, so that the pressure-resistant gasket structure has excellent corrosion and oxidation resistance.
[0021] 5. The present application wraps the sensing circuit and / or antenna with a protective layer, which can isolate the direct erosion of the external environment on the sensing circuit and / or antenna.
[0022] 6. The present application controls the stress concentration coefficient when the gasket body is drilled, which can avoid the failure problem of the gasket body caused by stress concentration due to drilling. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 is a front perspective structure diagram of the present pressure-resistant gasket structure; Figure 2 is a back perspective structure diagram of the present pressure-resistant gasket structure; Figure 3 is a side view of the present pressure-resistant gasket structure; Figure 4 is a rendering diagram of the present pressure-resistant gasket structure.
[0024] Wherein: 1, recess hole; 2, protective layer; 3, gasket body. DETAILED DESCRIPTION
[0025] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, all the inventions utilizing the concept of the present application are within the scope of the present application as defined and determined by the appended claims.
[0026] Embodiment one: As shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 , the compression-resistant gasket structure based on the pore structure includes a gasket body 3, the side surface of the gasket body 3 is provided with a protective layer 2, the protective layer 2 is provided with a sensing circuit and / or an antenna; the gasket body 3 is provided with a (one or more) recessed hole 1; the surface of the recessed hole 1 is provided with an insulating material, and the recessed hole 1 is filled with a sensitive material; The gasket body 3 is used to bear the external load and produce a controllable deformation acting on the sensitive material; The sensitive material produces a corresponding electrical signal in response to the deformation of the gasket body 3; The sensing circuit is electrically connected with the piezoelectric material and the antenna respectively, and generates a sensing signal in response to the electrical signal generated by the sensitive material; the sensing circuit can adopt a passive circuit; The antenna is used to transmit the sensing signal generated by the sensing circuit outward.
[0027] In the bolt fastening process, the bolt bearing surface is in direct contact with the gasket body 3, and it is found through simulation that under the same pressure, the pressure borne by the gasket body 3 decreases linearly from the inner ring to the outer ring, so the deformation of the gasket body 3 in the axial direction decreases linearly from the inside to the outside. When the pressure borne by the gasket body 3 is changed, the pressure borne by the gasket body 3 is positively correlated with the deformation, and as the pressure increases, the deformation of the gasket body 3 also increases. According to the actual scene requirements, it is particularly important to select the appropriate position of the gasket body 3 for opening and determine the size of the opening.
[0028] The gasket inner diameter and the gasket outer diameter corresponding to gasket bodies 3 of different sizes are different, so the ring width of the gasket body 3 is also different, which causes the opening position of the gasket body 3 to be unable to be accurately fixed to a certain value. In this embodiment, the gasket body 3 opening position optimization principle is established according to the characteristics of the gasket body 3: The recessed hole 1 is arranged on the upper surface of the gasket body 3, and the position of the recessed hole 1 satisfies the following conditions: Wherein is the position of the recessed hole 1; is the inner diameter of the gasket body 3; is the outer diameter of the gasket body 3; is a constant greater than or equal to 0.3 and less than or equal to 0.7, preferably greater than or equal to 0.45 and less than or equal to 0.55.
[0029] The size of the gasket body 3 opening varies according to the size of the gasket body 3. Under the condition of ensuring that it does not affect the original structure performance of the gasket body 3, the production and processing are reasonable, and the sensitive material design size is reasonable, etc. In order to meet the universality design of the gasket body 3 opening size, the equal proportion scaling rule and dynamic stress optimization model of the hole diameter and the gasket body 3 size need to be established to realize the design of the opening. Based on this, the size of the recessed hole 1 in the embodiment meets the following conditions: Wherein is the size of the recessed hole 1; is the hole diameter coefficient, is greater than or equal to 0.15 and less than or equal to 0.8; is the thickness of the gasket body 3; is the ring width of the gasket body 3.
[0030] When the thickness of the gasket body 3 is less than or equal to 1 millimeter, the recessed hole 1 is elliptical; when the thickness of the gasket body 3 is greater than 1 millimeter and less than 10 millimeters, the recessed hole 1 is circular; when the thickness of the gasket body 3 is greater than or equal to 10 millimeters, the recessed hole 1 is a racetrack ring.
[0031] The side surface of the gasket body 3 is L-shaped, and the protective layer 2 is located on the step formed by the L-shaped and flush with the step formed by the L-shaped.
[0032] In the embodiment, the opening of the recessed hole 1 is packaged with a packaging sheet of the same material as the gasket body 3, and the contact part of the packaging sheet and the sensitive material is provided with an insulating coating.
[0033] The bolt pre-tightening force generally refers to the force exerted by the bolt on the connected parts during the tightening process, and the pre-tightening force ensures the reliability of the connection. During the process of applying torque load on the bolt or nut, the bolt pre-tightening force will act on the gasket axial pressure and the plane torsion, and in most cases, the pre-tightening force of the bolt and the pressure received by the gasket are equal. In the embodiment, the gasket axial pressure is the main research object.
[0034] The recess 1 (i.e. micro hole) is processed on the gasket, and the original gasket structure strength is almost not attenuated, and the structure will not change the stress conduction form of the gasket body 3 under the condition of front pressure. Under the action of bolt pretightening force, since the gasket body 3 is the main bearing body of the bolt pretightening force, the bolt pretightening force is mainly applied to the gasket body 3, so as to protect the sensitive material. The gasket body 3 is pressed to cause the sensitive material in the gasket structure to be pressed, so that the sensitive material changes. Under this structure, the sensitive material will only respond to the vertical pressure, and the vertical pressure is the effect of the loaded bolt pretightening force.
[0035] The micro hole structure design makes the external pressure conduct to the material in the positive direction, and generates predictable deformation. Since the deformation area and degree are accurately constrained, the distance change stably corresponds to the change of the resonant frequency of different materials, and a clear pressure-frequency relationship model is established, that is, a stable conversion relationship between the measured pressure and the frequency of the electric signal is established.
[0036] In the embodiment, the sensitive material can be ceramic, crystal piezoelectric material or flexible high polymer material, inductive material. The deformation of the flexible high polymer material causes the distance between the electrodes to change, thereby causing the change of the capacitance, and the deformation of the inductive material causes the change of the length of the coil inside the inductive material or the change of the magnetic flux. Different types of sensitive materials change with the pressure, and finally can be reflected by the change of the resonant frequency. The resonant frequency change is transmitted to the external receiving device through the antenna, and the wireless transmission and analysis of the pressure data are completed.
[0037] The basic principle of the pressure-resistant gasket structure deformation force is based on the fact that the stress and strain of the gasket body 3 are in a linear relationship within the elastic limit of the gasket material, which can be expressed by the matrix form of Hooke's law, and the physical expression is as follows: Strain tensor: in three-dimensional space, strain can be represented as a second-order symmetric tensor, which includes 3 normal strain components and 3 shear strain components, that is: Wherein is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; x is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; x is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; y is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; z is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; z is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; x is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; y is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; x is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; z is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction; is the normal strain along the x-axis direction, corresponding to the length change rate of the x-axis direction;y - z Shear strain in the plane.
[0038] Due to material symmetry: ; The above matrix can be simplified into vector form: .
[0039] Stress tensor: The expression of stress tensor in terms of strain tensor is: where is the normal stress in the plane perpendicular to the x-axis; x is the normal stress in the plane perpendicular to the y-axis; is the normal stress in the plane perpendicular to the z-axis; is the shear stress in the plane along the x-direction; z is the shear stress in the plane along the y-direction; is the shear stress in the plane along the z-direction. x y x y z
[0040] Simplified vector form: ; Matrix expression of stress and strain: { σ}=[ D ]{ ε} where [D] is the elastic stiffness matrix, whose form depends on the elastic properties of the material.
[0041] In this embodiment, the material of the gasket body 3 is isotropic linear elastic material, whose elastic properties do not change with direction, and the stiffness matrix can be expressed by the elastic modulus E and the Poisson's ratio as: where "v" represents the Poisson's ratio of the material.
[0042] Through the above formula, the stress and strain relationship of the compression-resistant gasket structure in three-dimensional space can be converted into a linear algebra problem, and the mechanical response of the gasket structure can be conveniently solved by using numerical methods (finite element); at the same time, the elements representing the stiffness matrix of the gasket reflect the elastic coupling characteristics of the material, and the above formula expresses the correlation between the normal strain and the shear strain in the material through the Poisson's ratio.
[0043] Strain back-propagation expression: In this embodiment, the load distribution of the compression gasket structure is concentrated on the contact surface between the nut and the compression gasket structure, so that the stress distribution of the compression gasket structure is known, where [C] is the material elastic flexibility matrix, which is the inverse matrix of the material elastic stiffness [D].
[0044] The frequency and displacement conversion relationship is: According to the LC resonance circuit composed of inductance L and capacitance C, the formula of the resonance frequency is: Wherein is the resonance frequency, C is the capacitance; L is the inductance. From the above formula, it can be seen that the resonance frequency is determined by the energy storage characteristics of the inductance and the capacitance. When the capacitance or inductance value increases, the energy storage capacity of the system is enhanced, and the charging and discharging period is lengthened, resulting in a decrease in the resonance frequency; on the contrary, when the capacitance or inductance decreases, the resonance frequency increases. Therefore, the change of the resonance frequency can be monitored by the change of the capacitance and the inductance, and the sensitive material can be designed in two ways of measuring capacitance and measuring inductance.
[0045] When the sensitive material is designed to measure the capacitance, the calculation formula of the parallel plate capacitor is: Wherein C is the capacitance (unit: farad, F); ε is the dielectric constant of the dielectric (unit: F / m, ); A is the effective area of the parallel plate (unit: m²); The distance between the two plates (unit: m).
[0046] Under the action of the bolt pretightening force, the sensitive material in the recess hole 1 is deformed, thereby changing the distance between the two plates in the sensitive material, and the initial distance between the two plates is , the deformation value of the gasket body 3 is , and the distance between the two plates is The smaller the distance between the two plates, the larger the capacitance, and the smaller the resonance frequency.
[0047] When the sensitive material is designed to measure the inductance, the inductance value of the ideal coil is determined by its physical structure and material, and the formula is as follows: Wherein N is the total number of turns of the coil; μ is the magnetic permeability; A is the cross-sectional area of the coil (unit: square meter), and I is the length of the coil (unit: meter).
[0048] When the total number of turns of the sensitive material coil, the magnetic permeability, and the cross-sectional area of the coil are determined, the inductance L is inversely proportional to the length I of the coil. After the gasket body 3 is compressed, it is transmitted to the sensitive material, causing the length of the coil of the sensitive material to decrease, thereby causing the inductance to increase.
[0049] When the sensitive material is a piezoelectric material (e.g. ceramic, crystal, etc.), the resonant frequency can also be changed by the length change in the vibration direction of the piezoelectric material. Taking a quartz crystal material object as an illustration, the basic resonant frequency (fundamental frequency) of the quartz crystal resonator can be calculated by the following formula: Where n is the harmonic number of the vibration mode (n = 1 for the fundamental frequency), L is the length in the vibration direction of the crystal, C is the elastic constant related to the elastic properties of the crystal, and p is the density of the crystal.
[0050] As can be seen from the above formula, when the quartz crystal material is selected, the length in the vibration direction of the crystal will determine the size of the oscillation frequency. By comprehensively considering the conversion relationship between the bolt pretightening force and the displacement of the gasket body 3, the displacement of the gasket body 3 and the resonant length of the crystal are corresponded, and the compression deformation of the gasket body 3 can be linearly corresponded to the resonant frequency of the quartz crystal, thereby constructing a stable linear relationship between the bolt pretightening force and the resonant frequency.
[0051] In the present embodiment, the installation process of the compression-resistant gasket structure is consistent with that of a conventional gasket, and the compression-resistant gasket structure can be directly adapted to a device or apparatus that uses a conventional gasket without the need for special modification of the installation equipment.
[0052] The compression-resistant gasket structure provided in the present embodiment integrates the functions of an electrical signal processing circuit (sensing circuit), a communication antenna, pressure bearing, and environmental protection in one, directly receives external loads by the gasket body 3, generates a deformation effect on the sensitive material, obtains the resonant frequency of the sensitive material under the corresponding pressure through circuit conversion, integrates the sensing circuit and the antenna, and then integrally encapsulates them in the outer ring portion of the gasket body 3, and finally coats a protective layer on the surface of the gasket body 3. Such a design replaces the separate design idea of structure, sensing, and circuit in the conventional scheme, so that the gasket has a very high integration degree, and at the same time, reduces the assembly, debugging, and other work caused by separate design, and further reduces the production and manufacturing cost.
[0053] Embodiment Two The present embodiment is a further extension of Embodiment One, and the manufacturing method of the compression-resistant gasket structure based on the pore structure disclosed in the present embodiment includes the following steps: S1. Determine the position, shape, and size of the recess hole 1 according to the size data of the gasket body 3, and perform hole digging to form the recess hole 1; S2. Perform insulation treatment on the surface of the recess hole 1; S3. Cut the sensitive material according to the shape and size of the recess hole 1 to obtain a sensitive material matched with the recess hole 1; S4. Grow measurement electrodes on both poles of the sensitive material, integrally encapsulate the sensitive material with the grown measurement electrodes, and put them into the recess hole 1, and connect the measurement electrodes with the sensing circuit. S5, the sensitive material placed in the recess 1 is pre-stressed and packaged by using a packaging sheet made of the same material as the gasket body 3, so that the packaging sheet is in close contact with the sensitive material placed in the recess 1, and a gasket packaged with the packaging sheet is obtained; S6, the gasket packaged with the packaging sheet is subjected to insulation treatment as a whole, and an insulating treated gasket is obtained; S7, the insulating treated gasket, the sensing circuit and the antenna are placed in a mold, and an injection molding machine is used to inject an injection molding material into the mold, so that the injection molding material covers the sensing circuit and / or the antenna, and a protective layer 2 is formed.
[0054] In this embodiment, when the gasket body 3 is excavated, the stress concentration coefficient is controlled to be less than or equal to 1.3.
[0055] In this embodiment, the specific method for determining the position, shape and size of the recess 1 according to the size data of the gasket body 3 includes the following steps: S1-1, the position of the recess 1 is determined according to the inner diameter and the outer diameter of the gasket body 3, and the corresponding expression is: wherein is the position of the recess 1; is the inner diameter of the gasket body 3; is the outer diameter of the gasket body 3; is a constant greater than or equal to 0.3 and less than or equal to 0.7; S1-2, the size of the recess 1 is determined according to the thickness and the ring width of the gasket body 3, and the corresponding expression is: wherein is the size of the recess 1; is the aperture coefficient, is greater than or equal to 0.15 and less than or equal to 0.8; is the thickness of the gasket body 3; is the ring width of the gasket body 3; S1-3, the shape of the recess 1 is determined according to the thickness of the gasket body 3: when the thickness of the gasket body 3 is less than or equal to 1 mm, the recess 1 is elliptical; when the thickness of the gasket body 3 is greater than 1 mm and less than 10 mm, the recess 1 is circular; when the thickness of the gasket body 3 is greater than or equal to 10 mm, the recess 1 is a racetrack ring.
[0056] This embodiment completely decouples the influence of the gasket body 3 size, allowing the sensitive material to only perceive local strain rather than absolute displacement. The sensitive material can be piezoelectric material, flexible polymer material, or inductive material. Different types of sensitive material can perceive the pressure changes experienced by the gasket body 3. Thus, a standardized pressure sensing gasket structure is constructed that is not limited by the size of the gasket body 3.
[0057] In this embodiment, the following are the preferred implementation during production: Material selection: The gasket body 3 is made of metal material with high compressive strength and good processing performance; the protective layer 2 is made of ABS or polytetrafluoroethylene and other high polymer materials by one-piece injection molding; the recess 1 is processed by precision punching to form a micro-hole suitable for the sensitive material; and the overall compression gasket structure is insulated by non-metallic plating.
[0058] Processing technology: The gasket body 3 is made by stamping equipment, then the non-stress area groove is processed by lathe, and the hole position of the gasket body 3 is cut by precision punch, to create an integrated gasket body 3 with recess 1.
[0059] Metal gasket plating protection process: Clean the integrated gasket body 3 with recess 1, according to the different materials of the gasket body 3, use appropriate plating processes such as oxidation and electroplating to preliminarily insulate and protect the environment of the integrated gasket body 3 with recess 1.
[0060] Piezoelectric material packaging process: The sensitive material with polar plate is installed in the corresponding recess 1, and the polar plate of the piezoelectric material is connected to the corresponding circuit part, then a metal sheet with the size of the corresponding recess 1 is used to cover the piezoelectric device, and under the condition of maintaining the prestress, the metal sheet is welded to the gasket body 3 by laser welding.
[0061] One-piece injection molding process: The sensing circuit, antenna, and gasket with packaged piezoelectric material are placed in the mold, and then a specific injection material is injected into the mold by an injection molding machine, and after cooling, an integrated gasket is formed.
[0062] Surface protection process: Clean the integrated gasket after packaging, and according to different application scenarios, enter the corresponding surface plating process.
[0063] In this embodiment, during the non-pressure bearing stage of the compression gasket structure, the piezoelectric material will obtain initial deformation when the gasket is unloaded due to the pre-stress applied by the piezoelectric material and the metal gasket. Due to the existence of this pre-stress, the deformation of the gasket body 3 during the stress stage will continuously act on the piezoelectric material.
[0064] During the pressure bearing process of the pressure-resistant gasket structure, the surface pressure of the gasket body 3 continuously increases, according to the inherent characteristics of linear elastic materials, the gasket body 3 generates corresponding displacement in the stress direction, and the piezoelectric material inside the recess hole 1 will be directly extruded by the shrinkage displacement of the gasket body 3, resulting in the shift of the resonant frequency, and the frequency shift and the pressure applied on the gasket body 3 present a monotonic and linear change. After the gasket body 3 is unloaded, the metal gasket can quickly restore the shape, and the voltage material simultaneously restores to the initial state.
[0065] In the embodiment, a non-preferred solution is also provided: Material selection: the gasket body 3 is selected from non-metallic materials with high strength, good creep resistance and easy processing; the protective layer 2 is formed by curing and molding of epoxy resin material; and the recess hole 1 is processed by a milling machine with a flat milling cutter.
[0066] Processing technology: the initial gasket body 3 is obtained by means of thermoplastic, injection molding, hot pressing, powder metallurgy, etc., the initial gasket body 3 is clamped on the milling machine, the flat milling cutter is used to process the recess hole 1, the piezoelectric material is placed in the recess hole 1, the non-metallic gasket corresponding to the size of the recess hole 1 is placed in the recess hole 1, and the gasket is sealed by ultrasonic welding under the condition of applying pre-stress; after the sensing circuit, antenna and piezoelectric device are assembled, the gasket is placed in the glue pouring mold, and the gasket is sealed as a whole by injecting epoxy resin.
[0067] In all implementation processes, the main difference of the pressure-resistant gasket structure lies in the pressure-bearing material of the gasket body 3. The metal gasket has higher structural strength and can be applied to scenes with large load, but the processing technology is relatively complicated, the processing precision is relatively high, and therefore the cost is relatively high. The raw material of the non-metallic gasket is easy to shape, has good insulation characteristics, and can reduce the construction process of the coating, thereby saving the production cost; but the load of the non-metallic gasket is relatively low, and it is suitable for low-load environment. According to the use scene of the pressure-resistant gasket structure, the metal gasket has wide application range and large load, and belongs to the preferred solution. The non-metallic gasket has good insulation characteristics but low load, and belongs to the non-preferred solution.
[0068] In summary, the gasket body 3 is processed with the recess hole 1 at a proper position, and the sensitive material is embedded in the recess hole 1 through a later process, so as to measure the pressure of the gasket body 3 through the sensitive material. The size, position and shape of the reserved recess hole 1 fully consider the structural mechanics problem, so that the pressure deformation of the gasket body 3 uniformly acts on the sensitive material; meanwhile, the position of the recess hole 1 processed on the gasket body 3 does not damage the original gasket compression area, and does not cause damage to the structural strength of the original gasket; combined with the high stability and anti-interference characteristics of the sensitive material, a stable relationship between pressure conduction and linear deformation of the sensitive material is established, thereby improving the accuracy and stability of pressure measurement.
Claims
1. A pressure-resistant gasket structure based on a porous structure, characterized in that, Includes a gasket body (3), a protective layer (2) is provided on the side of the gasket body (3), and a sensing circuit and / or antenna is provided in the protective layer (2); a recess (1) is provided on the gasket body (3); an insulating material is provided on the surface of the recess (1), and a sensitive material is filled in the recess (1); The gasket body (3) is used to bear external loads and generate controllable deformation to act on sensitive materials; The sensitive material generates a corresponding electrical signal in response to the deformation of the gasket body (3); The sensing circuit is electrically connected to the piezoelectric material and the antenna, respectively, and generates a sensing signal in response to the electrical signal generated by the sensitive material. Antennas are used to transmit the sensing signals generated by the sensing circuit to the outside.
2. The anti-compression gasket structure based on a porous structure according to claim 1, characterized in that, A recess (1) is provided on the upper surface of the gasket body (3), and the position of the recess (1) satisfies the following conditions: in The location of the concave hole (1); The inner diameter of the gasket body (3); The outer diameter of the gasket body (3); It is a constant greater than or equal to 0.3 and less than or equal to 0.
7.
3. The anti-compression gasket structure based on a porous structure according to claim 2, characterized in that, The value is greater than or equal to 0.45 and less than or equal to 0.
55.
4. The anti-compression gasket structure based on a porous structure according to claim 1, characterized in that, The dimensions of the concave hole (1) satisfy the following conditions: in The dimensions of the concave hole (1); For aperture coefficient, Greater than or equal to 0.15 and less than or equal to 0.8; The thickness of the gasket body (3); The circumference of the gasket body (3) is denoted as .
5. The anti-compression gasket structure based on a porous structure according to claim 1, characterized in that, When the thickness of the pad body (3) is less than or equal to 1 mm, the recess (1) is elliptical; when the thickness of the pad body (3) is greater than 1 mm but less than 10 mm, the recess (1) is circular; when the thickness of the pad body (3) is greater than or equal to 10 mm, the recess (1) is a runway ring.
6. The anti-compression gasket structure based on a porous structure according to claim 1, characterized in that, The side of the gasket body (3) is L-shaped, and the protective layer (2) is located on the step formed by the L-shape and is flush with the step formed by the L-shape.
7. The anti-compression gasket structure based on a porous structure according to claim 1, characterized in that, The opening of the recess (1) is encapsulated with a packaging sheet of the same material as the gasket body (3), and the contact area between the packaging sheet and the sensitive material is provided with an insulating coating.
8. A method for manufacturing a pressure-resistant gasket structure based on a porous structure as described in any one of claims 1 to 7, characterized in that, Includes the following steps: The location, shape and size of the recess (1) are determined based on the size data of the gasket body (3), and the recess (1) is formed by drilling. Insulation treatment is performed on the surface of the concave hole (1); The sensitive material is cut according to the shape and size of the concave hole (1) to obtain a sensitive material that matches the concave hole (1); Measurement electrodes are grown on both poles of the sensitive material. The sensitive material on which the measurement electrodes are grown is encapsulated as a whole and placed in the concave hole (1). The measurement electrodes are then connected to the sensing circuit. A prestressed encapsulation is performed on the sensitive material placed in the recess (1) using an encapsulation sheet of the same material as the gasket body (3), so that the encapsulation sheet and the sensitive material placed in the recess (1) are in close contact, and a gasket encapsulated with the encapsulation sheet is obtained; wherein the contact part between the encapsulation sheet and the sensitive material is provided with an insulating coating. The entire gasket containing the encapsulated chip is insulated to obtain an insulated gasket. The insulating gasket, sensing circuit and antenna are placed into the mold, and the injection molding material is injected into the mold by the injection molding machine so that the injection molding material covers the sensing circuit and / or antenna to form a protective layer (2).
9. The manufacturing method according to claim 8, characterized in that, When drilling holes in the gasket body (3), the stress concentration factor is controlled to be within 1.
3.
10. The manufacturing method according to claim 8, characterized in that, The specific methods for determining the location, shape, and size of the recess (1) based on the dimensional data of the gasket body (3) include: The position of the recess (1) is determined based on the inner and outer diameters of the gasket body (3), and the corresponding expression is: in The location of the concave hole (1); The inner diameter of the gasket body (3); The outer diameter of the gasket body (3); It is a constant greater than or equal to 0.3 and less than or equal to 0.7; The dimensions of the recess (1) are determined based on the thickness and circumference of the gasket body (3), and the corresponding expression is: in The dimensions of the concave hole (1); For aperture coefficient, Greater than or equal to 0.15 and less than or equal to 0.8; The thickness of the gasket body (3); The circumferential width of the gasket body (3); The shape of the recess (1) is determined based on the thickness of the gasket body (3): When the thickness of the gasket body (3) is less than or equal to 1 mm, the concave hole (1) is elliptical; When the thickness of the gasket body (3) is greater than 1 mm and less than 10 mm, the concave hole (1) is circular; When the thickness of the pad body (3) is greater than or equal to 10 mm, the concave hole (1) is a runway ring.