Compression type acceleration sensor with cymbal type structure and simulation method thereof

Abstract

The invention discloses a compression type acceleration sensor with a cymbal type structure and a simulation method thereof, and belongs to the field of sensors. The sensor comprises a nut, a screw rod, a base, a mass block, a cymbal type piezoelectric material composite structure and an insulating sheet, the nut, the screw rod and the base jointly form a pre-tightening piece, and the cymbal type piezoelectric material composite structure comprises an upper cymbal body, a piezoelectric sheet and a lower cymbal body; a threaded hole is formed in the nut, one end of the screw rod is fixedly connected with the base, the cymbal type piezoelectric material composite structure, the insulating sheet and the mass block are sequentially and coaxially sleeved on the screw rod, the nut is nested at the other end of the screw rod, and the threaded hole of the nut is matched with an external thread on the screw rod. According to the cymbal structure, common utilization of piezoelectric coefficients d31 and d33 is achieved, and the amplification effect of the cymbal structure on charges under different cone angles is verified and calculated through finite element simulation software. According to the structural design, the charge sensitivity of the sensor is effectively improved while the light weight of the sensor is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and in particular relates to a compression acceleration sensor with a cymbal structure and a simulation method thereof. Background Art

[0002] Accelerometers, which measure the acceleration of an object, are widely used in health monitoring applications such as aircraft engines and nuclear power plants. Because these applications expose them to strong electromagnetic interference, radiation, shock, and high temperatures, they must meet specific requirements for resistance to strong shock, radiation, and extreme temperatures.

[0003] For compression sensors, their structure generally includes a base, a piezoelectric element, and a mass block. The piezoelectric element is placed on the base, and the mass block is connected to the base and presses the piezoelectric element against the surface of the base. With this structure, when the acceleration sensor moves as a whole, the mass block can apply pressure to the piezoelectric element, so that the piezoelectric element can detect the pressure applied by the mass block and then calculate the acceleration based on the pressure. In order to improve the sensitivity of the acceleration sensor, it is usually necessary to increase the mass of the mass block or increase the number of piezoelectric sheets electrically connected in parallel to improve the sensitivity of the acceleration sensor. However, increasing the mass of the mass block will cause the acceleration sensor to be heavier as a whole and cannot meet the lightweight usage requirements. Increasing the number of piezoelectric sheets electrically connected in parallel will cause the natural frequency of the acceleration sensor to decrease, while increasing the cost and increasing the difficulty of assembly. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, the present invention provides a compression-type acceleration sensor with a cymbal-type structure and a simulation method thereof. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] In a first aspect, the present invention provides a compression-type acceleration sensor having a cymbal-type structure, comprising a nut, a screw, a base, a mass, a cymbal-type piezoelectric material composite structure, and an insulating sheet, wherein the nut, screw, and base together constitute a preload member, and the cymbal-type piezoelectric material composite structure comprises an upper cymbal body, a piezoelectric sheet, and a lower cymbal body arranged in sequence, the piezoelectric sheet being an annular sheet coaxially disposed between the upper cymbal body and the lower cymbal body, with the upper cymbal body and the piezoelectric sheet bonded together, and the lower cymbal body and the piezoelectric sheet bonded together;

[0006] A threaded hole is provided on the nut, one end of the screw is fixedly connected to the base, the cymbal-type piezoelectric material composite structure, the insulating sheet and the mass block are coaxially inserted into the screw in sequence, and the nut is nested in the other end of the screw, and the threaded hole of the nut matches the external thread on the screw. The pre-tightening force is applied by the pre-tightening member to press the mass block, the insulating sheet and the cymbal-type piezoelectric material composite structure onto the base in sequence, and the top surfaces of the upper cymbal body and the lower cymbal body are subjected to positive extrusion pressure.

[0007] In one embodiment of the present invention, the base is a hexagonal prism, and a threaded blind hole is provided at the bottom of the base. One end of the screw is connected to the threaded blind hole of the base, and the other end is provided with an external thread for connecting to a nut.

[0008] In one embodiment of the present invention, the upper cymbal body and the lower cymbal body are made of the same material and are both made of metal.

[0009] In one embodiment of the present invention, the upper cymbal body is a hollow truncated cone-shaped body, wherein the wide end of the upper cymbal body is the bottom surface of the truncated cone, and the narrow end of the upper cymbal body is the top surface of the truncated cone.

[0010] In one embodiment of the present invention, the lower cymbal body is a hollow truncated cone-shaped body, wherein the wide end of the lower cymbal body is the top surface of the truncated cone, and the narrow end of the lower cymbal body is the bottom surface of the truncated cone.

[0011] In one embodiment of the present invention, the top surface of the upper cymbal body and the top surface of the lower cymbal body are consistent with the size of the end surface of the insulating sheet.

[0012] In one embodiment of the present invention, the piezoelectric piece is polarized along the axial direction, and the piezoelectric piece is a ring-shaped piezoelectric ceramic element.

[0013] In one embodiment of the present invention, a first adhesive layer is provided between the upper cymbal body and the piezoelectric sheet, and a second adhesive layer is provided between the lower cymbal body and the piezoelectric sheet. The materials of the first adhesive layer and the second adhesive layer are both high-temperature conductive glue or high-temperature conductive metal welding layer.

[0014] In a second aspect, the present invention provides a simulation method for a compression acceleration sensor having a cymbal structure, which is applied to the compression acceleration sensor having a cymbal structure as provided in the above-mentioned solution. The compression acceleration sensor includes a nut, a screw, a base, a mass block, a cymbal-type piezoelectric material composite structure, and an insulating sheet. The cymbal-type piezoelectric material composite structure includes an upper cymbal body, a piezoelectric sheet, and a lower cymbal body arranged in sequence. The method includes:

[0015] The first formula is used to calculate the electric displacement of the cymbal-type piezoelectric material composite structure when it is subjected to an axial force. The first formula is:

[0016] D3=-d 31 X3cotβ+d 33 X3

[0017] Wherein, D3 is the electric displacement of the piezoelectric element of the compression acceleration sensor, d 33 is the longitudinal piezoelectric coefficient of the piezoelectric sheet, d 31 is the transverse piezoelectric coefficient of the piezoelectric sheet, X3 is the stress of the piezoelectric element, and β is the cone angle of the cymbal structure, that is, the transverse force conversion angle. For piezoelectric ceramics, the longitudinal piezoelectric coefficient d 33 and the transverse piezoelectric coefficient d 31 opposite signs;

[0018] The charge amplification effect is verified based on the calculated electric displacement.

[0019] In one embodiment of the present invention, COMSOL Multiphysics finite element simulation software is used to verify the charge amplification effect;

[0020] Specifically include:

[0021] Step 1: Set the cone angle of the upper and lower cymbal bodies to the first angle. During the simulation, set the mechanical boundary conditions as follows: the bottom of the sensor base is selected as a fixed constraint, and the acceleration of the sensor is controlled by the body load of the entire device.

[0022] Step 2: The piezoelectric coefficient d of the piezoelectric piece 31 Set to -127pC / N, and change the piezoelectric coefficient d 33 Set to 492pC / N to control the movement of the compression accelerometer and detect the charge of the first piezoelectric signal output by the piezoelectric piece;

[0023] Step 3: The piezoelectric coefficient d of the piezoelectric piece 31 Set to 0, the piezoelectric coefficient d 33 Set to 492pC / N to control the movement of the compression accelerometer and detect the charge of the second piezoelectric signal output by the piezoelectric piece;

[0024] Step 4: The piezoelectric coefficient d of the piezoelectric piece 31 Set to -127pC / N, and change the piezoelectric coefficient d 33 Set to 0 to control the movement of the compression accelerometer and detect the charge of the third piezoelectric signal output by the piezoelectric piece;

[0025] Step 5: comparing the charge amounts of the first piezoelectric signal, the second piezoelectric signal, and the third piezoelectric signal;

[0026] Step 6: Set the cone angles of the upper cymbal body and the lower cymbal body to the second angle, and repeat the above steps 1 to 5. The angle values ​​of the first angle and the second angle are not equal.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The above scheme of the present application includes a nut, a screw, a base, a mass block, a cymbal-type piezoelectric material composite structure and an insulating sheet, wherein the nut, the screw and the base together constitute a pre-tightening member, and the cymbal-type piezoelectric material composite structure includes an upper cymbal body, a piezoelectric sheet and a lower cymbal body arranged in sequence, the piezoelectric sheet is an annular sheet body, the piezoelectric sheet is coaxially arranged between the upper cymbal body and the lower cymbal body, and the upper cymbal body and the piezoelectric sheet are bonded, and the lower cymbal body and the piezoelectric sheet are bonded; a threaded hole is provided on the nut, one end of the screw is fixedly connected to the base, the cymbal-type piezoelectric material composite structure, the insulating sheet and the mass block are coaxially inserted into the screw in sequence, the nut is nested in the other end of the screw, and the threaded hole of the nut cooperates with the external thread on the screw, and a pre-tightening force is applied by the pre-tightening member to press the mass block, the insulating sheet and the cymbal-type piezoelectric material composite structure onto the base in sequence, and the top surfaces of the upper cymbal body and the lower cymbal body are both subjected to positive extrusion pressure. With this structure, when the acceleration sensor moves as a whole, the mass block can apply pressure to the upper cymbal body, and the upper cymbal body can apply pressure to the piezoelectric sheet, causing the piezoelectric sheet to deform to generate an electrical signal. By acquiring the electrical signal, the acceleration of the target object can be calculated. The above-mentioned acceleration sensor of the present application sets a cymbal-type piezoelectric material composite structure, so that the upper cymbal body and the lower cymbal body can apply a force perpendicular to the surface of the piezoelectric sheet and a force parallel to the surface of the piezoelectric sheet after being subjected to force, thereby causing the piezoelectric sheet to further expand along the radial direction on the basis of compression deformation. Therefore, the piezoelectric performance of the piezoelectric sheet is affected by both the piezoelectric coefficient d 33 The influence of the piezoelectric coefficient d 31 The influence of the piezoelectric coefficient d 33 and the piezoelectric coefficient d 31 This increases the charge signal of the piezoelectric patch and improves the sensitivity of the acceleration sensor. Therefore, there is no need to increase the mass of the mass block or the number of piezoelectric patches electrically connected in parallel to improve the sensitivity of the acceleration sensor. This allows the acceleration sensor described above to meet lightweight requirements while avoiding the reduction in the natural frequency of the acceleration sensor, which increases cost and assembly difficulty, as is often the case with increasing the number of piezoelectric patches electrically connected in parallel.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of an acceleration sensor in an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of a piezoelectric sheet according to an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of a nut in an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of an upper cymbal body according to an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of an insulating sheet according to an embodiment of the present invention;

[0035] Figure 6 Schematic diagram of a screw and a base in an embodiment of the present invention;

[0036] Figure 7 FIG. 4 is a schematic diagram of the sensitivity of the acceleration sensor at different cone angles according to an embodiment of the present invention.

[0037] Figure numerals: 1-nut, 2-screw, 3-base, 4-mass block, 5-cymbal-type piezoelectric material composite structure, 51-upper cymbal body, 52-piezoelectric sheet, 53-lower cymbal body, 6-insulating sheet. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0039] Example 1:

[0040] See Figures 1 to 6 An embodiment of the present invention provides a compression acceleration sensor having a cymbal-type piezoelectric material composite structure 5, comprising a nut 1, a screw 2, a base 3, a mass block 4, a cymbal-type piezoelectric material composite structure 5 and an insulating sheet 6, wherein the nut 1, the screw 2 and the base 3 together constitute a pre-tightening member, and the cymbal-type piezoelectric material composite structure 5 includes an upper cymbal body 51, a piezoelectric sheet 52 and a lower cymbal body 53 arranged in sequence, the piezoelectric sheet is an annular sheet, and the piezoelectric sheet 52 is coaxially located between the upper cymbal body 51 and the lower cymbal body 53 and bonded to the bottom surfaces of the two. Nut 1 is provided with a threaded hole, and one end of screw rod 2 is fixedly connected to base 3. The cymbal piezoelectric material composite structure 5, insulating sheet 6, and mass block 4 are coaxially inserted into screw rod 2 in sequence. The threaded hole of nut 1 is then inserted into the external thread at the other end of screw rod 2 to mate with it. By applying a preload force to the preload mechanism, mass block 4, insulating sheet 6, and cymbal piezoelectric material composite structure 5 are sequentially compressed and bound to base 3. At this time, the top surfaces of the upper cymbal body 51 and the lower cymbal body 53 are both subjected to positive extrusion pressure. Due to the stress-bearing characteristics of the cymbal piezoelectric material composite structure itself, the upper and lower end surfaces of the piezoelectric sheet 52 are both subjected to axial pressure and radial expansion force. When the device is subjected to acceleration, the pressure transmitted from mass block 4 and insulating sheet 6 to the upper cymbal body 51 and the lower cymbal body 53 changes, causing the axial pressure and radial expansion force on the annular piezoelectric sheet 52 to also change. Due to the piezoelectric effect, the piezoelectric sheet 52 generates induced charge.

[0041] In some embodiments of the present application, Figure 1 and Figure 3As shown, the nut 1 can be a hexagonal nut.

[0042] In some embodiments of the present application, Figure 1 and Figure 6 As shown, the base 3 is a hexagonal prism, and a mounting threaded blind hole is provided at the bottom of the base 3. One end of the screw rod 2 is directly and integrally connected to the base 3, and the other end is provided with an external thread for connection.

[0043] In some embodiments of the present application, the upper cymbal body 51 and the lower cymbal body 53 are hollow truncated cone bodies made of completely identical metal materials, such as Figure 4 As shown, the wide end is the bottom surface of the truncated cone, and the narrow end is the top surface of the truncated cone.

[0044] In some embodiments of the present application, the piezoelectric piece 52 is polarized along the axial direction. From the perspective of process implementation, it can be a single-piece annular piezoelectric ceramic element or a multi-layer (n-layer) co-fired and electrically connected in parallel annular piezoelectric ceramic element.

[0045] In some embodiments of the present application, the mass block 4 and the insulating sheet 6 are both circular ring structures, the top surfaces of the upper cymbal body 51 and the lower cymbal body 53 are consistent with the size of the circular ring surface of the insulating sheet 6, and the mass block 4, the cymbal-type piezoelectric material composite structure 5 and the insulating sheet 6 are all coaxially matched with the screw 2 with a non-zero gap.

[0046] In some embodiments of the present application, the top surface of the upper cymbal body 51 faces the insulating sheet 6, and the bottom surface faces the piezoelectric ceramic ring 52; the bottom surface of the lower cymbal body 53 faces the annular piezoelectric ceramic, and the top surface faces the base 3. The two cymbals are symmetrically arranged about the piezoelectric sheet 52 to form a cymbal-type piezoelectric material composite structure 5. A first connecting layer is provided between the upper cymbal body 51 and the piezoelectric sheet 52, and a second connecting layer is provided between the lower cymbal body 53 and the piezoelectric sheet 52. Both the first and second bonding layers are high-temperature conductive adhesive layers or high-temperature conductive metal welding layers.

[0047] In some embodiments of the present application, Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the cymbal-type piezoelectric material composite structure 5, the insulating sheet 6, and the mass block 4 are coaxially nested on the screw 2 in sequence, and are all pre-tightened parts; then the nut 1 is nested on the screw 2 and connected with its thread, and the pre-tightening force is applied to the pre-tightened parts through the relative rotation of the nut 1 and the screw 2.

[0048] In some embodiments of the present application, the nut 1, the screw 2, the base 3, and the mass block 4 are all Inconel series alloys with excellent high-temperature performance, and the insulating sheet 6 is alumina ceramic; the materials of the upper cymbal body 51 and the lower cymbal body 53 can be selected according to the difficulty of the processing technology, and can generally be made of 3D printed 316L stainless steel.

[0049] In some embodiments of the present application, taking the acceleration sensor base close to a horizontal plane and subjected to upward acceleration as an example, at this time, due to the increase in the pressure exerted by the inertial mass block 4 of the part itself on the upper cymbal body 51, after the action of the cymbal-type piezoelectric material composite structure 5, the piezoelectric piece 52 is subjected to a corresponding increase in the positive pressure along the axial direction and the radial expansion force, causing the piezoelectric piece 52 to further undergo axial contraction and radial expansion deformation, thereby achieving the longitudinal piezoelectric coefficient d of the piezoelectric piece 52 33 and the transverse piezoelectric coefficient d 31 while using.

[0050] In some embodiments of the present application, the piezoelectric sheet 52 satisfies the following formula under ideal conditions:

[0051] D3=-d 31 X3cotβ+d 33 X3

[0052] Wherein, D3 is the electric displacement of the piezoelectric element of the compression acceleration sensor, d 33 is the longitudinal piezoelectric coefficient of the piezoelectric sheet, d 31 is the transverse piezoelectric coefficient of the piezoelectric sheet, X3 is the stress of the piezoelectric element, and β is the cone angle of the cymbal piezoelectric material composite structure, that is, the transverse force conversion angle. For piezoelectric ceramics, the longitudinal piezoelectric coefficient d 33 and the transverse piezoelectric coefficient d 31 The signs are opposite, so the use of cymbal-type piezoelectric material composite structure can effectively increase the amount of electrical signals.

[0053] In some embodiments of the present application, the cone angle of the upper cymbal body 51 and the lower cymbal body 53 refers to the angle between the generatrix of the inner annular surface and the axis thereof.

[0054] In the above scheme of the present application, the acceleration sensor includes a nut 1, a screw 2, a base 3, a mass block 4 and a cymbal-type piezoelectric material composite structure 5. The nut 1 is provided with a threaded hole. One end of the screw 2 is fixedly connected to the base 3, and the other end is inserted into the threaded hole and threadedly engaged with the threaded hole. A mass block 4 and a cymbal-type piezoelectric material composite structure 5 are provided between the nut 1 and the base 3. The cymbal-type piezoelectric material composite structure 5 includes an upper cymbal body 51, a piezoelectric sheet 52 and a lower cymbal body 53 arranged in sequence. One end of the screw 2 is connected to the nut 1, and the other end passes through the mass block 4, the upper cymbal body 51, the piezoelectric sheet 52 and the lower cymbal body 53 in sequence and is connected to the base 3. When the nut 1 is rotated relative to the screw 2, it squeezes the mass block 4 to apply pressure to the cymbal-type piezoelectric material composite structure 5, so as to press the cymbal-type piezoelectric material composite structure 5 tightly against the base 3. With this structure, when the acceleration sensor moves as a whole, the mass block 4 can apply pressure to the upper cymbal body 51, and the upper cymbal body 51 can apply pressure to the piezoelectric sheet 52, so that the piezoelectric sheet 52 can be deformed to generate an electrical signal. By obtaining the electrical signal, the acceleration of the target object can be calculated. The above-mentioned acceleration sensor of the present application sets a cymbal-type piezoelectric material composite structure 5, so that the upper cymbal body 51 and the lower cymbal body 53 can apply a force perpendicular to the surface of the piezoelectric sheet 52 and a force parallel to the surface of the piezoelectric sheet 52 after being subjected to force, thereby making the piezoelectric sheet further expand along the radial direction on the basis of compression deformation. The piezoelectric performance of the piezoelectric sheet 52 is affected by both the piezoelectric coefficient d 33 The influence of the piezoelectric coefficient d 31 The influence of the piezoelectric coefficient d 33 and the piezoelectric coefficient d 31 To increase the charge signal of the piezoelectric piece and improve the sensitivity of the acceleration sensor. Through the above design, the acceleration sensor in this application can effectively increase the charge sensitivity performance of the sensor while meeting the requirements of lightweight use.

[0055] Example 2:

[0056] The present invention provides a simulation method for a compression acceleration sensor having a cymbal structure, which is used to verify the charge amplification effect. The method is applied to the compression acceleration sensor having a cymbal structure as provided in the above-mentioned solution. The acceleration sensor includes a mass block 4 and a cymbal-type piezoelectric material composite structure 5. The cymbal-type piezoelectric material composite structure 5 includes an upper cymbal body 51, a piezoelectric sheet 52, and a lower cymbal body 53 arranged in sequence. The method involved in one embodiment of the present invention includes:

[0057] As mentioned in the first embodiment, the cymbal-type piezoelectric material composite structure 5 ideally satisfies the following formula when subjected to an axial force:

[0058] D3=-d 31 X3cotβ+d 33 X3

[0059] For existing traditional compression accelerometers, the mass block directly presses on the annular piezoelectric element. The electric displacement of the piezoelectric element when subjected to axial force satisfies the following formula:

[0060] D3=d 33 X3

[0061] Therefore, from a preliminary formula point of view, the use of cymbal piezoelectric material composite structure can achieve charge amplification and sensitivity improvement of acceleration sensor based on traditional compression sensor.

[0062] In one embodiment of the present invention, a simulation method for verifying the charge amplification effect using COMSOL Multiphysics finite element simulation software includes:

[0063] Step 1: Set the cone angle of the upper and lower cymbal bodies to the first angle. During simulation, set the mechanical boundary conditions as follows: the bottom of the sensor base is selected as a fixed constraint, and the acceleration of the sensor is controlled by the body load of the entire device.

[0064] Step 2: The piezoelectric coefficient d of the piezoelectric piece 31 Set to -127pC / N, and change the piezoelectric coefficient d 33 Set to 492pC / N to control the movement of the sensor and detect the charge of the first piezoelectric signal output by the piezoelectric piece;

[0065] Step 3: The piezoelectric coefficient d of the piezoelectric piece 31 Set to 0, the piezoelectric coefficient d 33 Set to 492pC / N to control the sensor movement and detect the charge of the second piezoelectric signal output by the piezoelectric piece;

[0066] Step 4: The piezoelectric coefficient d of the piezoelectric piece 31 Set to -127pC / N, and change the piezoelectric coefficient d 33 Set to 0 to control the movement of the sensor and detect the charge of the third piezoelectric signal output by the piezoelectric piece;

[0067] Step 5: comparing the charge amounts of the first piezoelectric signal, the second piezoelectric signal, and the third piezoelectric signal;

[0068] Step 6: Set the cone angles of the upper cymbal body and the lower cymbal body to the second angle, and repeat the above steps 1 to 5. The angle values ​​of the first angle and the second angle are not equal.

[0069] Comparing the calculation results revealed that the charge output of the cymbal-type accelerometer varies at different cone angles. The charge of the first, second, and third piezoelectric signals at each angle is the sum of the charges of the first, second, and third piezoelectric signals. By comparing the charge of the first piezoelectric signal at each angle, the optimal cone angle can be determined.

[0070] The beneficial effects of the second embodiment of the present invention and its various implementations can be analyzed with reference to the beneficial effects of the first embodiment and its various implementations, and will not be repeated here.

[0071] In some embodiments of the present application, the simulation software adopts COMSOL Multiphysics developed by the Swedish COMSOL Group, and the material parameters in the simulation (including but not limited to density, Young's modulus, Poisson's ratio, and piezoelectric coefficient) are all derived from relevant literature.

[0072] The calculation formulas given in the above embodiments 1 and 2 show that for the piezoelectric coefficient d in the cymbal-type acceleration sensor, 33 and d 31 The simulation of Example 2 calculates the piezoelectric coefficient d of the cymbal accelerometer at different cone angles. 33 and d 31 The contribution of Figure 7 The cone angle of the cymbal piezoelectric composite structure has a significant impact on its amplification effect. One reason is that the radial expansion force converted at different angles is different. 31 The amount of charge generated is different; another reason is that the stress concentration caused by pressure at different angles is different, so d 33 The amount of charge generated is also different. Under the current size conditions, when the cone angle is 45°, the charge sensitivity performance of the accelerometer is optimal.

[0073] In some embodiments of the present application, using the same mass size, piezoelectric coefficient, and boundary conditions, calculations show that the sensitivity of a conventional compression accelerometer is 31.4 pC / g. However, when using the accelerometer with the cymbal-like piezoelectric material composite structure described above, its overall sensitivity is far greater than that of the conventional compression accelerometer, and when the cone angle is 45°, the sensitivity of the accelerometer described above can reach 52.7 pC / g. This demonstrates that the compression accelerometer with the cymbal-like structure described above can achieve charge amplification, and the use of this highly sensitive sensor can effectively improve detection accuracy.

[0074] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0076] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0077] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A compression acceleration sensor having a cymbal structure, characterized in that: The cymbal-type piezoelectric material composite structure comprises a nut, a screw, a base, a mass block, a cymbal-type piezoelectric material composite structure, and an insulating sheet, wherein the nut, screw, and base together constitute a pre-tightening member, and the cymbal-type piezoelectric material composite structure comprises an upper cymbal body, a piezoelectric sheet, and a lower cymbal body arranged in sequence, the piezoelectric sheet being an annular sheet, the piezoelectric sheet being coaxially arranged between the upper cymbal body and the lower cymbal body, and the upper cymbal body and the piezoelectric sheet being bonded together, and the lower cymbal body and the piezoelectric sheet being bonded together; A threaded hole is provided on the nut, one end of the screw is fixedly connected to the base, the cymbal-type piezoelectric material composite structure, the insulating sheet and the mass block are coaxially inserted into the screw in sequence, the nut is nested in the other end of the screw, and the threaded hole of the nut cooperates with the external thread on the screw, and a pre-tightening force is applied by the pre-tightening member to press the mass block, the insulating sheet and the cymbal-type piezoelectric material composite structure onto the base in sequence, and the top surfaces of the upper cymbal body and the lower cymbal body are subjected to positive extrusion pressure.

2. The compression acceleration sensor with a cymbal structure according to claim 1, wherein: The base is a hexagonal prism, and a threaded blind hole is provided at the bottom of the base. One end of the screw rod is connected and matched with the threaded blind hole of the base, and the other end is provided with an external thread for connecting and matching with the nut.

3. The compression acceleration sensor with a cymbal structure according to claim 1, wherein: The upper cymbal body and the lower cymbal body are made of the same material and are both made of metal.

4. The compression acceleration sensor with a cymbal structure according to claim 3, wherein: The upper cymbal body is a hollow truncated cone-shaped body, and the wide end of the upper cymbal body is the bottom surface of the truncated cone, and the narrow end is the top surface of the truncated cone.

5. The compression acceleration sensor with a cymbal structure according to claim 4, wherein: The lower cymbal body is a hollow truncated cone-shaped body, and the wide end of the lower cymbal body is the top surface of the truncated cone, and the narrow end of the lower cymbal body is the bottom surface of the truncated cone.

6. The compression acceleration sensor with a cymbal structure according to claim 5, characterized in that: The top surface of the upper cymbal body and the top surface of the lower cymbal body are both consistent with the size of the end surface of the insulating sheet.

7. The compression acceleration sensor with a cymbal structure according to claim 1, wherein: The piezoelectric piece is polarized along the axial direction and is a ring-shaped piezoelectric ceramic element.

8. The compression acceleration sensor with a cymbal structure according to claim 1, wherein: A first adhesive layer is provided between the upper cymbal body and the piezoelectric sheet, and a second adhesive layer is provided between the lower cymbal body and the piezoelectric sheet. Both the first adhesive layer and the second adhesive layer are high-temperature conductive adhesive layers or high-temperature conductive metal welding layers.

9. A simulation method for a compression acceleration sensor with a cymbal structure, used to verify the charge amplification effect, characterized in that: A compression acceleration sensor having a cymbal structure according to any one of claims 1 to 8, the compression acceleration sensor comprising a nut, a screw, a base, a mass block, a cymbal piezoelectric material composite structure, and an insulating sheet, the cymbal piezoelectric material composite structure comprising an upper cymbal body, a piezoelectric sheet, and a lower cymbal body arranged in sequence, the method comprising: The first formula is used to calculate the electric displacement of the cymbal-type piezoelectric material composite structure when it is subjected to an axial force. The first formula is: D3=-d 31 X3cotβ+d 33 X3 Wherein, D3 is the electric displacement of the piezoelectric element of the compression acceleration sensor, d 33 is the longitudinal piezoelectric coefficient of the piezoelectric sheet, d 31 is the transverse piezoelectric coefficient of the piezoelectric sheet, X3 is the stress of the piezoelectric element, β is the cone angle of the cymbal structure, that is, the transverse force conversion angle. For piezoelectric ceramics, the longitudinal piezoelectric coefficient d 33 and the transverse piezoelectric coefficient d 31 opposite signs; The charge amplification effect is verified based on the calculated electric displacement.

10. The simulation method of the compression acceleration sensor with a cymbal structure according to claim 9, characterized in that: The method further comprises: Use COMSOL Multiphysics finite element simulation software to verify the charge amplification effect; Specifically include: Step 1: The cone angles of the upper cymbal body and the lower cymbal body are set to a first angle. During the simulation, the mechanical boundary conditions are set as follows: the bottom of the sensor base is selected as a fixed constraint, and the acceleration of the sensor is controlled by the body load of the entire device; Step 2: The piezoelectric coefficient d of the piezoelectric sheet 31 Set to -127pC / N, and the piezoelectric coefficient d 33 Set to 492 pC / N, control the movement of the compression acceleration sensor, and detect the charge of the first piezoelectric signal output by the piezoelectric piece; Step 3: The piezoelectric coefficient d of the piezoelectric sheet 31 Set to 0, the piezoelectric coefficient d 33 Set to 492 pC / N, control the movement of the compression acceleration sensor, and detect the charge of the second piezoelectric signal output by the piezoelectric piece; Step 4: The piezoelectric coefficient d of the piezoelectric sheet 31 Set to -127pC / N, and the piezoelectric coefficient d 33 Set to 0, control the movement of the compression acceleration sensor to detect the charge amount of the third piezoelectric signal output by the piezoelectric piece; Step 5: comparing the charge amounts of the first piezoelectric signal, the second piezoelectric signal, and the third piezoelectric signal; Step 6: Set the cone angles of the upper cymbal body and the lower cymbal body to a second angle, and repeat the above steps 1 to 5. The angle values ​​of the first angle and the second angle are not equal.

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