Metal diaphragm applied to pressure sensor and design method thereof

Abstract

The invention discloses a metal diaphragm applied to a pressure sensor and a design method thereof, and belongs to the technical field of sensors, the metal diaphragm is provided with a central circular plane and T-shaped circular corrugations, a plurality of S-shaped circular corrugations are arranged between the central circular plane and the T-shaped circular corrugations, the outer edge of the T-shaped outer corrugations is provided with an outer straight edge circular plane, and the outer straight edge circular plane is provided with an inner straight edge circular plane. According to the metal diaphragm, the rigidity of the metal diaphragm can be reduced, and the pressure sensing effect of the metal diaphragm is improved. By improving the size, arrangement, number and other combination designs of the T-shaped outer corrugations and the S-shaped circular corrugations, the loss of sensing the initial pressure by the metal diaphragm can be reduced, the pressure conduction efficiency is improved, the initial sensitivity of the metal diaphragm is improved, and the service life of the metal diaphragm is prolonged. The problem that in the prior art, due to the fact that a metal diaphragm is insufficient in sensitivity, the requirements of a small-sized, micro-pressure and high-precision sensor are difficult to meet is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a metal diaphragm applied to a pressure sensor and a design method thereof. Background Art

[0002] As the sensing element of the pressure sensor, the metal diaphragm has the characteristics of large overload, high sensitivity and corrosion resistance. The metal diaphragm has a simple structure, simple manufacturing, low cost, flexible interface and wide versatility. It is widely used in the fields of petrochemical, aerospace, shipbuilding, etc., among which pressure sensor is one of its main application scenarios.

[0003] Metal diaphragms are mainly used to sense the pressure changes of external media such as gases and liquids, and transmit the sensed pressure to the solution system in the form of elastic deformation or pressure to calculate the pressure value of the measured medium. Currently, metal diaphragms are used in sensors and are generally used as pressure sensing elements. However, since the stiffness of the metal diaphragm itself is affected by the material, surface, and thickness, pressure loss will be generated during the pressure sensing and transmission process, resulting in pressure sensing errors.

[0004] At present, this problem is mainly solved by adjusting the thickness, diameter and corrugation size of the diaphragm material. It is not obvious in traditional mechanical instruments. However, with the promotion of metal diaphragms in MEMS cores, combined with the trend of improving the sensing accuracy of pressure sensors, miniaturizing the test pressure value and miniaturizing sensors, the above control measures are becoming increasingly limited. For example, the diaphragm with the highest sensitivity listed in JB / T7485 is "diameter φ16mm, thickness 0.05mm, and its sensitivity is 0.00099mm / kPa", which is converted to 9.9×10 -4 μm / Pa. At present, some domestic diaphragms have reduced the thickness of the diaphragm to 0.02mm. When the diameter is reduced to φ12mm, the sensitivity of the metal diaphragm can only reach 2.5×10 -2 μm / Pa, it is difficult to meet the needs of miniaturization, micro-pressure and high-precision sensors. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a metal diaphragm for use in a pressure sensor and a design method thereof, so as to solve the problem that the metal diaphragm in the prior art is unable to meet the requirements of miniaturized, micro-pressure and high-precision sensors due to insufficient sensitivity.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] Provided is a metal diaphragm for a pressure sensor, comprising a central circular plane and a T-shaped circular corrugation, a plurality of S-shaped circular corrugations being arranged between the central circular plane and the T-shaped circular corrugation, an outer straight-edge circular plane being arranged at the outer edge of the T-shaped outer corrugation, and the centers of the plurality of S-shaped circular corrugations, the center of the T-shaped circular corrugation and the center of the outer straight-edge circular plane all coincide with the center of the central circular plane.

[0008] The basic principle of the metal diaphragm used in the pressure sensor in this scheme is: the metal diaphragm adopts the above-mentioned structural setting, which can reduce the rigidity of the metal diaphragm itself and improve the metal diaphragm's perception of pressure. By improving the size, arrangement, number and other combined designs of the T-shaped outer corrugation and multiple S-shaped circular corrugations, the loss of the metal diaphragm in sensing the initial pressure can be reduced, and its pressure transmission efficiency can be improved, thereby improving the initial sensitivity of the metal diaphragm, solving the problem that the metal diaphragm in the prior art is difficult to meet the needs of miniaturization, micro-pressure and high-precision sensors due to insufficient sensitivity.

[0009] Furthermore, the corrugation depth of the T-shaped circular corrugation and the plurality of S-shaped circular corrugations is 0.06 mm to 0.11 mm. If the corrugation depth is too small, the elasticity of the metal diaphragm decreases, and if the corrugation depth is too large, the metal diaphragm profile stiffness increases, both of which will lead to decreased sensitivity. By limiting the corrugation depth to 0.06 mm to 0.11 mm, the metal diaphragm can have good elasticity and good sensitivity.

[0010] Furthermore, the diameter of the outer straight edge circular plane is D1, the working diameter of the metal diaphragm is D2, and the calculation formula of the working diameter D2 of the metal diaphragm is: D2 = (0.8-0.9) × D1. This ratio is beneficial to leave sufficient interface between the metal diaphragm and the structural part, so as to improve the connection and stability of the metal diaphragm and reduce the influence of heat effects such as welding on the metal diaphragm profile.

[0011] Furthermore, the corrugation height of the T-shaped circular corrugation is H1, H1=(0.01-0.13)×D1; wherein D1 is the diameter of the outer straight edge circular plane;

[0012] The plurality of S-shaped circular corrugations are evenly spaced between the T-shaped circular corrugations and the center circular plane, and the corrugation heights of the plurality of S-shaped circular corrugations are h1, h2, h3, ... hN, respectively, wherein h1 = h2 = h3 = hN = (0.8-1) × H1; when the sensitivity of the metal diaphragm is not higher than 0.00099 mm / kPa, the number of S-shaped circular corrugations is three, and the number of S-shaped circular corrugations increases by one for every 2 orders of magnitude increase in the sensitivity of the metal diaphragm. The purpose of this arrangement is to distinguish the functions of the T-shaped circular corrugations and the S-shaped circular corrugations in the design, highlight the supporting role of the waveform T-shaped circular corrugations, while reducing the S-shaped circular corrugations to reduce the cold work hardening of the material and improve the sensitivity of the metal diaphragm.

[0013] Furthermore, the corrugation depths of the plurality of S-shaped circular corrugations are all δ1, and the calculation formula for the corrugation depth δ1 of the S-shaped circular corrugations is: δ1=(0.6-0.8)×h1.

[0014] Furthermore, the diameter of the center circle plane is d1, and the calculation formula of the center circle plane diameter d1 is: d1 = (0.22-0.25) × D2. The ratio of the center circle plane diameter d1 to the metal diaphragm working diameter D2 is not less than 1:5, which improves the uniformity and stability of the metal diaphragm output.

[0015] The present invention also provides a design method for a metal diaphragm used in a pressure sensor, which comprises the following steps:

[0016] S1. Determine the diameter D1 of the outer straight edge circular plane of the metal diaphragm according to the installation size of the pressure sensor, determine the number of S-shaped circular corrugations according to the sensitivity requirements of the diaphragm, and determine the interval between multiple S-shaped circular corrugations and the diameter of each S-shaped circular corrugation according to the diameter d1 of the central circular plane and the working diameter D2 of the metal diaphragm;

[0017] S2. According to the outer straight edge circle plane diameter D1 in step S1, the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation are calculated; the calculation formula of the working diameter D2 of the metal diaphragm is:

[0018] D2 = (0.8-0.9) × D1;

[0019] The calculation formula for the corrugation height H1 of the T-shaped circular corrugation is:

[0020] H1=(0.01~0.13)×D1;

[0021] S3, according to the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation in step S2, respectively calculate the center circle plane diameter d1 and multiple S-shaped circular corrugation heights h1, h2, h3, ... hN;

[0022] The calculation formula of the center circle plane diameter d1 is:

[0023] d1=(0.22~0.25)×D2;

[0024] The calculation formula for the heights of multiple S-shaped circular corrugations h1, h2, h3, ... hN is:

[0025] h1=h2=h3=hN=(0.8~1)×H1;

[0026] S4, according to the height h1 of the S-shaped circular corrugation in step S3, the corrugation depth δ1 of the S-shaped circular corrugation is calculated, and the calculation formula of the corrugation depth δ1 is: δ1=(0.6-0.8)×h1;

[0027] S5. Obtain a metal diaphragm with design parameters.

[0028] The beneficial effects of the present invention are as follows: compared with the metal diaphragm in the prior art, the metal diaphragm and its design method used in the present solution for pressure sensors replace the traditional Y-shaped circular corrugation with a T-shaped circular corrugation, which greatly reduces the initial stiffness value of the metal diaphragm while ensuring the support of the overall profile of the metal diaphragm, and reduces the hysteresis of the metal diaphragm's initial pressure perception by adjusting the shape and size of the metal diaphragm corrugation. The metal diaphragm profile design effectively improves the sensitivity of the metal diaphragm itself and reduces the size of the metal diaphragm. Taking a diaphragm with an outer diameter of φ12mm and a thickness of 0.02mm as an example, the sensitivity of the metal diaphragm can be increased from 2.5×10 -2 μm / Pa increased to 1.6×10 -1 μm / Pa, the initial sensitivity is 3×10 -1 μm / Pa increased to 1×10 -1 μm / Pa, which greatly reduces the loss of the metal diaphragm as a pressure transmission element and narrows the detection dead zone of the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a schematic diagram of the structure of a metal diaphragm used in a pressure sensor.

[0030] Among them, 1. Center circular plane; 2. T-shaped circular corrugation; 3. S-shaped circular corrugation; 4. Outer straight edge circular plane. DETAILED DESCRIPTION

[0031] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0032] like Figure 1 As shown, the present invention provides a metal diaphragm used for a pressure sensor, which includes a central circular plane 1 and a T-shaped circular corrugation 2, a plurality of S-shaped circular corrugations 3 are arranged between the central circular plane 1 and the T-shaped circular corrugation 2, an outer straight-edge circular plane 4 is arranged at the outer edge of the T-shaped outer corrugation, and the centers of the plurality of S-shaped circular corrugations 3, the centers of the T-shaped circular corrugations 2 and the outer straight-edge circular plane 4 all coincide with the center of the central circular plane 1. The metal diaphragm adopts the above-mentioned structural arrangement, which can reduce the rigidity of the metal diaphragm itself and improve the metal diaphragm's perception effect on pressure. By improving the combined design of the size, arrangement, quantity, etc. of the T-shaped outer corrugation and the plurality of S-shaped circular corrugations 3, the loss of the metal diaphragm in sensing the initial pressure can be reduced, and the efficiency of its pressure conduction can be improved, thereby improving the initial sensitivity of the metal diaphragm, solving the problem that the metal diaphragm in the prior art is difficult to meet the requirements of miniaturization, micro-pressure, and high-precision sensors due to insufficient sensitivity.

[0033] Specifically, the corrugation depth of the T-shaped circular corrugation 2 and the plurality of S-shaped circular corrugations 3 is 0.06 mm to 0.11 mm. If the corrugation depth is too small, the elasticity of the metal diaphragm decreases, and if the corrugation depth is too large, the rigidity of the metal diaphragm profile increases, both of which will lead to a decrease in sensitivity. By limiting the corrugation depth to 0.06 mm to 0.11 mm, the metal diaphragm can have good elasticity and good sensitivity.

[0034] The diameter of the outer straight edge circular plane 4 is D1, the working diameter of the metal diaphragm is D2, and the calculation formula of the working diameter D2 of the metal diaphragm is: D2 = (0.8-0.9) × D1. This ratio is beneficial to leave sufficient interface between the metal diaphragm and the structural part, so as to improve the connection and stability of the metal diaphragm and reduce the influence of heat such as welding on the metal diaphragm profile.

[0035] The corrugation height of the T-shaped circular corrugation 2 is H1, H1 = (0.01-0.13) × D1; wherein D1 is the diameter of the outer straight edge circular plane 4;

[0036] The corrugation heights of the plurality of S-shaped circular corrugations 3 are h1, h2, h3, ... hN, respectively, wherein h1 = h2 = h3 = hN = (0.8-1) × H1. The plurality of S-shaped circular corrugations 3 are evenly spaced between the T-shaped circular corrugations 1 and the central circular plane 1. When the sensitivity of the metal diaphragm is not higher than 0.00099 mm / kPa, the number of the S-shaped circular corrugations 3 is three, and the number of the S-shaped circular corrugations 3 increases by one for every 2 orders of magnitude increase in the sensitivity of the metal diaphragm. The purpose of such a setting is to distinguish the functions of the T-shaped circular corrugations 1 and the S-shaped circular corrugations 3 in the design, highlight the supporting role of the waveform T-shaped circular corrugations 1, while reducing the S-shaped circular corrugations 3 to reduce the cold work hardening of the material and improve the sensitivity of the metal diaphragm.

[0037] Furthermore, the corrugation depths of the plurality of S-shaped circular corrugations 3 are all δ1, and the calculation formula of the corrugation depth δ1 of the S-shaped circular corrugations 3 is: δ1=(0.6-0.8)×h1.

[0038] Furthermore, the diameter of the central circular plane 1 is d1, and the calculation formula of the diameter d1 of the central circular plane 1 is: d1 = (0.22-0.25) × D2. The ratio of the diameter d1 of the central circular plane 1 to the working diameter D2 of the metal diaphragm is not less than 1:5, which improves the uniformity and stability of the output of the metal diaphragm.

[0039] The present invention also provides a design method for a metal diaphragm used in a pressure sensor, which comprises the following steps:

[0040] S1 determines the diameter D1 of the outer straight edge circular plane 4 of the metal diaphragm according to the installation size of the pressure sensor, determines the number of S-shaped circular corrugations 3 according to the sensitivity requirements of the diaphragm, and determines the interval between multiple S-shaped circular corrugations 3 and the diameter of each S-shaped circular corrugation 3 according to the diameter d1 of the central circular plane 1 and the working diameter D2 of the metal diaphragm;

[0041] S2. According to the diameter D1 of the outer straight edge circular plane 4 in step S1, the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation 2 are calculated; the calculation formula of the working diameter D2 of the metal diaphragm is:

[0042] D2 = (0.8-0.9) × D1;

[0043] The calculation formula for the corrugation height H1 of the T-shaped circular corrugation 2 is:

[0044] H1=(0.01~0.13)×D1;

[0045] S3, according to the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation 2 in step S2, respectively calculate the diameter d1 of the center circle plane 1 and the heights h1, h2, h3, ..., hN of the plurality of S-shaped circular corrugations 3;

[0046] The calculation formula for the diameter d1 of the center circle plane 1 is:

[0047] d1=(0.22~0.25)×D2;

[0048] The calculation formula for the heights h1, h2, h3, ..., hN of multiple S-shaped circular corrugations 3 is:

[0049] h1=h2=h3=hN=(0.8~1)×H1;

[0050] S4, according to the height h1 of the S-shaped circular corrugation 3 in step S3, calculate the corrugation depth δ1 of the S-shaped circular corrugation 3, and the calculation formula of the corrugation depth δ1 is: δ1=(0.6-0.8)×h1;

[0051] S5. Obtain a metal diaphragm with design parameters.

[0052] Compared with the metal diaphragm in the prior art, the metal diaphragm and its design method used in the present solution for pressure sensor replace the traditional Y-shaped circular corrugation with T-shaped circular corrugation 2. The metal diaphragm uses T-shaped circular corrugation 2 and multiple S-shaped circular corrugations 3 as the basis. While ensuring the support of the overall surface of the metal diaphragm, the processing stress of the metal diaphragm is reduced, the initial stiffness value of the metal diaphragm is greatly reduced, and the hysteresis of the metal diaphragm's initial pressure perception is reduced by adjusting the shape and size of the metal diaphragm corrugation. The metal diaphragm surface design effectively improves the perception sensitivity of the metal diaphragm itself and reduces the size of the metal diaphragm. Taking the diaphragm with an outer diameter of φ12mm and a thickness of 0.02mm as an example, the sensitivity of the metal diaphragm can be reduced from 2.5×10 -2 μm / Pa increased to 1.6×10 -1 μm / Pa, the initial sensitivity is 3×10 -1 μm / Pa increased to 1×10 -1 μm / Pa, which greatly reduces the loss of the metal diaphragm as a pressure transmission element and narrows the detection dead zone of the pressure sensor.

Claims

1. A metal diaphragm used in a pressure sensor, characterized in that: It includes a central circular plane and a T-shaped circular corrugation, a plurality of S-shaped circular corrugations are arranged between the central circular plane and the T-shaped circular corrugation, an outer straight-edge circular plane is arranged at the outer edge of the T-shaped outer corrugation, and the centers of the plurality of S-shaped circular corrugations, the centers of the T-shaped circular corrugations and the centers of the outer straight-edge circular plane all coincide with the center of the central circular plane.

2. The metal diaphragm for pressure sensor according to claim 1, characterized in that: The corrugation depth of the T-shaped circular corrugation and the plurality of S-shaped circular corrugations is 0.06 mm to 0.11 mm.

3. The metal diaphragm for pressure sensor according to claim 2, characterized in that: The diameter of the outer straight edge circular plane is D1, the working diameter of the metal diaphragm is D2, and the calculation formula of the working diameter D2 of the metal diaphragm is: D2 = (0.8-0.9) × D1.

4. The metal diaphragm for pressure sensor according to claim 3, characterized in that: The corrugation height of the T-shaped circular corrugation is H1, H1 = (0.01-0.13) × D1; wherein D1 is the diameter of the outer straight edge circular plane; The plurality of S-shaped circular corrugations are evenly spaced between the T-shaped circular corrugations and the central circular plane, and the corrugation heights of the plurality of S-shaped circular corrugations are h1, h2, h3, ... hN, respectively, wherein h1 = h2 = h3 = hN = (0.8-1) × H1; when the sensitivity of the metal diaphragm is not higher than 0.00099 mm / kPa, the number of the S-shaped circular corrugations is three, and the number of the S-shaped circular corrugations increases by one for every 2 orders of magnitude increase in the sensitivity of the metal diaphragm.

5. The metal diaphragm for a pressure sensor according to claim 4, characterized in that: The corrugation depths of the plurality of S-shaped circular corrugations are all δ1, and the calculation formula for the corrugation depth δ1 of the S-shaped circular corrugations is: δ1=(0.6-0.8)×h1.

6. The metal diaphragm for a pressure sensor according to claim 5, characterized in that: The diameter of the center circle plane is d1, and the calculation formula of the center circle plane diameter d1 is: d1 = (0.22-0.25) × D2.

7. A method for designing a metal diaphragm for a pressure sensor according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Determine the diameter D1 of the outer straight edge circular plane of the metal diaphragm according to the installation size of the pressure sensor, determine the number of S-shaped circular corrugations according to the sensitivity requirements of the diaphragm, and determine the interval between multiple S-shaped circular corrugations and the diameter of each S-shaped circular corrugation according to the diameter d1 of the central circular plane and the working diameter D2 of the metal diaphragm; S2. According to the outer straight edge circle plane diameter D1 in step S1, the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation are calculated; the calculation formula of the working diameter D2 of the metal diaphragm is: D2 = (0.8-0.9) × D1; The calculation formula for the corrugation height H1 of the T-shaped circular corrugation is: H1=(0.01~0.13)×D1; S3, according to the working diameter D2 of the metal diaphragm and the corrugation height H1 of the T-shaped circular corrugation in step S2, respectively calculate the center circle plane diameter d1 and multiple S-shaped circular corrugation heights h1, h2, h3, ... hN; The calculation formula of the center circle plane diameter d1 is: d1=(0.22~0.25)×D2; The calculation formula for the heights of multiple S-shaped circular corrugations h1, h2, h3, ... hN is: h1=h2=h3=hN=(0.8~1)×H1; S4, according to the height h1 of the S-shaped circular corrugation in step S3, the corrugation depth δ1 of the S-shaped circular corrugation is calculated, and the calculation formula of the corrugation depth δ1 is: δ1=(0.6-0.8)×h1; S5. Obtain a metal diaphragm with design parameters.

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