Piezoelectric composite material element assembly tool and assembly method

Abstract

The invention discloses a piezoelectric composite material element assembly tool and method, and belongs to the technical field of transducer manufacturing, the piezoelectric composite material element assembly tool comprises a base, a cover plate, a positioning fastening mechanism, a self-adaptive pressure control unit and a special tool connected with an external computer, traditional tin soldering is replaced with a bonding process, the contact area of a piezoelectric composite material and a metal soldering lug is enlarged, and the piezoelectric composite material element assembly efficiency is improved. The problems of few tin soldering points and insufficient strength are solved; coaxiality and parallelism of the cylindrical containing cavity and the flexible protection pad are guaranteed, and part damage caused by pressurization is avoided. Pressure-deformation adaptive logic and a temperature difference compensation coefficient are adopted, pressure distribution is automatically adjusted, thermal expansion is adapted, stress concentration is reduced, and the later falling risk is avoided; and the adhesive rheology monitoring and automatic adhesive supplementing are realized, high-frequency slight shock is realized, the problems of insufficient adhesive amount or too fast curing are solved, and the stable acoustic performance of the transducer is ensured.

Description

Technical Field

[0001] This invention relates to the field of transducer manufacturing technology, specifically to a piezoelectric composite material component assembly fixture and assembly method. Background Technology

[0002] In the manufacturing of underwater acoustic transducers, piezoelectric composite material elements need to convert acoustic signals into electrical signals through metal solder sheets. Existing assembly processes mostly use soldering, that is, after the piezoelectric composite material surface is polarized and silver-plated, it is welded to the annular metal solder sheet through the annular through hole.

[0003] The process has a core defect: the welding points are concentrated only at the through holes and are few in number; in addition, the performance of the silver plating layer on the surface of the piezoelectric composite material varies, resulting in insufficient connection strength between the metal solder sheet and the piezoelectric composite material; during the later use of the component, the metal solder sheet is prone to detach from the piezoelectric composite material due to mechanical or electrical stress in the marine environment, which directly leads to the failure of the transducer's acoustic performance and seriously affects the product quality and service life. Summary of the Invention

[0004] On the one hand, in order to solve the problems of the prior art, the present invention provides a piezoelectric composite material component assembly fixture, comprising: The base is used to support the piezoelectric composite material components to be assembled. The top end face of the base is provided with a receiving cavity for accommodating the piezoelectric composite material component to be assembled. A cover plate, located above the base, is used to cooperate with the base to apply pressure to the component to be assembled; The positioning and fastening mechanism has its two ends connected to the base and the cover plate respectively. The distance between the cover plate and the base can be adjusted by operating the positioning and fastening mechanism. An adaptive pressure control unit, connected to an external computer, is located between the base and the cover plate, and connected to the top end face of the base. It is used to detect in real time the pressure applied by the cover plate to the component to be assembled.

[0005] Furthermore, the receiving cavity is a cylindrical cavity, and a through ejection hole is provided on the bottom of the receiving cavity; A circular groove coaxial with the receiving cavity is provided on the bottom end face of the cover plate; The circular groove and the receiving cavity are provided with protective mechanisms to protect the components to be assembled during the assembly process.

[0006] Furthermore, the protective mechanism includes: an upper protective pad and a lower protective pad; The upper protective pad is disposed in the circular groove during use, and the lower protective pad is disposed in the receiving cavity during use; both the upper and lower protective pads are made of flexible material. The upper protective pad and the lower protective pad have the same thickness.

[0007] Furthermore, the adaptive pressure control unit includes: a guide seat, a pressure sensor, a push rod, and a spring; One end of the top rod is fixedly connected to the bottom end face of the cover plate; The bottom of the guide seat is fixedly connected to the top end face of the base; The top end face of the guide seat is provided with a first deep hole and a second deep hole; The diameter of the first deep hole is greater than the diameter of the second deep hole, the depth of the first deep hole is greater than the depth of the second deep hole, and the first deep hole and the second deep hole are concentrically arranged; The diameter of the second deep hole is larger than the diameter of the push rod, and the other end of the push rod is located inside the first deep hole; The pressure sensor is disposed at the top of the second deep hole and is connected to the computer; The spring is sleeved on the top rod above the pressure sensor.

[0008] Furthermore, the positioning mechanism includes: a positioning pin, a pressing column, a drive rod, and a pressure plate; At least three positioning pins are provided and distributed in a circumferential direction on the top end face of the base. Correspondingly, the cover plate is provided with through holes adapted to the positions of the positioning pins, and the upper end of the positioning pin passes through the through hole. At least three pressing posts are provided, and they are distributed in a circumferential direction on the top end face of the cover plate, and their positions are different from those of the through holes; One end of the drive rod is rotatably connected to the center of the top end face of the cover plate; The pressure plate is sleeved on the drive rod, and a groove is provided on the bottom end face of the pressure plate to match the position of the pressing column.

[0009] On the other hand, this application provides a method for assembling piezoelectric composite material components. The method is implemented based on a piezoelectric composite material component assembly fixture, wherein the fixture is equipped with an adaptive pressure linkage system that can dynamically match the cover plate pressure and the downward pressing distance according to the material and structure of the assembly components. The method includes the following steps: Step 1: Clean the surfaces of the piezoelectric composite material and the metal welding sheet to be bonded to meet the bonding requirements; Step 2: Prepare a pre-strength adhesive, apply it, and then bond the two together to form an assembly component; Step 3: Place the component in the tooling cavity and protect it with the protective mechanism. After closing the cover plate, fix it in place. Collect the component characteristics through the adaptive pressure linkage system, calculate the pressure and downward pressure distance reference, preset the control parameters and phased strategies, and collect pressure data. Step 4: Compare the real-time pressure with the preset benchmark pressure, and dynamically adjust the pressing distance of the cover plate in combination with the component curing deformation to optimize the control efficiency and stability in stages; during this process, an early warning is triggered, and the adhesive is set to be cured after the early warning is lifted, and then demolded after cooling.

[0010] Furthermore, in step 3, when calculating the pressure and downward pressure distance, different coefficients are used for components made of different materials: If the assembly component is a rigid piezoelectric composite material, the pressure reference should be 0.3 to 0.5 MPa, and the pressure distance reference coefficient should be 0.8 to 0.9. If it is a flexible piezoelectric composite material, the pressure reference is 0.1 to 0.3 MPa, and the pressure distance reference coefficient is 0.9 to 1.0. When the real-time pressure approaches 90% of the baseline upper limit, the control rate is reduced by 50%. When collecting component characteristics, an adaptive collection method is used for components of different sizes. If the component is a miniature piezoelectric element, the thickness is collected by a laser thickness gauge and the local hardness is collected by a microhardness tester. For large piezoelectric components, a multi-point data acquisition method should be used; Thickness sampling points ≥ 5, hardness sampling points ≥ 6, and the average value is taken as the characteristic parameter; When setting preset adjustment parameters, adjust them based on the adhesive type; If thermosetting adhesives are used, the allowable range of pressure fluctuations during the curing stage is reduced to ±5%, and the feedback frequency is increased to 3-4 Hz; If room temperature curing adhesive is used, the adjustment parameters should be kept within a fluctuation range of ±10%, and the pressure maintenance time should be extended by 1 to 2 hours at the end of the curing period.

[0011] Furthermore, in step 3, when preset the control parameters, a dynamic adaptation logic of pressure-deformation-protection is constructed based on the material deformation coordination data collected in real time by the adaptive pressure linkage system. When collecting component characteristics, the adaptive pressure linkage system simultaneously records the elastic deformation curve of the piezoelectric composite material under a preset pressure. If the curve shows nonlinear fluctuations, it is determined that there is local stress concentration in the material, and the circumferential pressure distribution of the positioning and fastening mechanism is automatically adjusted. When the components are piezoelectric composite materials and metal sheets of different materials, the system formulates a temperature difference compensation coefficient in the pressure reference based on the difference in the thermal expansion coefficients of the two materials. If the ambient temperature difference is greater than 5°C in the subsequent curing stage, the adaptive system automatically adjusts the downward pressure distance according to the temperature difference compensation coefficient.

[0012] Furthermore, in step 4, the pressure control process needs to be linked with the monitoring of adhesive rheological properties to achieve the prediction and dynamic correction of abnormal risks. While collecting real-time pressure, the adaptive pressure control unit indirectly monitors the rheological resistance of the adhesive through feedback from the gap between the push rod and the guide seat: if the resistance value increases by more than 30% within 10 seconds, it is determined that the adhesive is mixed with impurities or locally cured too quickly. The system immediately triggers the positioning and fastening mechanism to perform micro-loosening or rapid tightening action, while driving the pressing column on the cover plate to generate high-frequency micro-vibration. If the resistance value remains below 60% of the reference range, it is determined that the adhesive coating is insufficient. The system automatically calls the ejector hole at the bottom of the receiving cavity and blows the spare adhesive reserved on the side wall of the receiving cavity to the area lacking adhesive through a small amount of airflow. After the adhesive is replenished, the pressure control is restored.

[0013] The beneficial effects of this invention are: By using a specialized fixture with an adaptive pressure control unit and a positioning fastening mechanism, and replacing traditional soldering with an adhesive bonding process, the contact area between the piezoelectric composite material and the metal solder sheet is expanded, solving the problems of insufficient soldering points and weak connection strength. The cylindrical receiving cavity and flexible protective pad of the fixture ensure the coaxiality and parallelism of the two components during assembly, while preventing damage to the components under pressure. Through the dynamic adaptation logic of pressure-deformation-protection and the temperature difference compensation coefficient, the circumferential pressure distribution can be automatically adjusted to adapt to the thermal expansion differences of the materials, reducing local stress concentration and avoiding the risk of detachment caused by mechanical / electrical stress in the later stage. Through the monitoring of adhesive rheological properties and automatic glue replenishment, and the high-frequency micro-vibration function, the problem of insufficient glue or excessive local curing can be corrected in time, ultimately ensuring the stable acoustic performance of the transducer. Attached Figure Description

[0014] Figure 1 A schematic diagram of the three-dimensional structure of the assembly tooling provided by the present invention; Figure 2 A schematic diagram of the side structure of the assembly tooling provided by the present invention; Figure 3 A schematic diagram of the positioning and fastening mechanism provided by the present invention; Figure 4 A schematic diagram of the adaptive pressure control unit structure provided by the present invention; Figure 5 This is a schematic diagram of the assembly method provided by the present invention.

[0015] Figure label: In the diagram: 1 is the base, 2 is the cover plate, 3 is the upper protective pad, 4 is the lower protective pad, 5 is the guide seat, 6 is the pressure sensor, 7 is the top rod, 8 is the spring, 9 is the positioning pin, 10 is the pressing column, 11 is the drive rod, and 12 is the pressure plate. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 Please see Figure 1-5 This invention provides a piezoelectric composite material component assembly fixture, comprising: Base 1 is used to support the piezoelectric composite material component to be assembled; The top end face of the base 1 is provided with a receiving cavity for accommodating the piezoelectric composite material component to be assembled. Cover plate 2, which is located above the base 1, is used to cooperate with the base 1 to apply pressure to the component to be assembled; The positioning and fastening mechanism has its two ends connected to the base 1 and the cover plate 2 respectively. The distance between the cover plate 2 and the base 1 can be adjusted by operating the positioning and fastening mechanism. An adaptive pressure control unit, connected to an external computer, is located between the base 1 and the cover plate 2 and is connected to the top end face of the base 1. It is used to detect the pressure applied by the cover plate 2 to the component to be assembled in real time.

[0018] The base is made of 2A12 material, and its top end face has a cylindrical cavity that is adapted to the size of the piezoelectric composite material component to be assembled. The cover plate is made of 20Cr13 material. The adaptive pressure control unit establishes data transmission with an external computer through wires, which can feed back the real-time collected pressure data to the computer, realize the visual monitoring and precise control of the pressure value, and avoid damage to the component due to excessive pressure or affect the bonding strength due to insufficient pressure. The positioning and fastening mechanism provides a stable and adjustable pressurization environment for the component by adjusting the distance between the cover plate and the base.

[0019] In some embodiments, the receiving cavity is a cylindrical cavity, and a through ejection hole is provided on the bottom of the receiving cavity; A circular groove coaxial with the receiving cavity is provided on the bottom end face of the cover plate 2; The circular groove and the receiving cavity are provided with protective mechanisms to protect the components to be assembled during the assembly process.

[0020] The cavity has a Ф5mm through ejection hole at its bottom. After the component has cured, it can be smoothly ejected by passing a needle through the ejection hole, avoiding damage to the bonding structure caused by manual removal. The coaxiality error between the circular groove on the bottom end face of the cover plate and the cavity is ≤0.1mm. The protective mechanism is set in the circular groove and the cavity, and can be made of polytetrafluoroethylene (non-metallic material). This avoids surface scratches caused by direct contact between the metal base / cover plate and the piezoelectric composite material, and also facilitates the cleaning of excess adhesive during the bonding process.

[0021] In some embodiments, the protective mechanism includes: an upper protective pad 3 and a lower protective pad 4; The upper protective pad 3 is disposed in the circular groove during use, and the lower protective pad 4 is disposed in the receiving cavity during use; both the upper protective pad 3 and the lower protective pad 4 are made of flexible material; The upper protective pad 3 and the lower protective pad 4 have the same thickness.

[0022] The upper protective pad is adapted to the size of the circular groove at the bottom of the cover plate, and the lower protective pad is adapted to the size of the receiving cavity. Both are 2-3mm thick and consistent to ensure that the upper and lower surfaces of the component are subjected to balanced force. The flexible material has temperature resistance and can withstand the temperature environment of the subsequent curing process, avoiding material deformation at high temperatures that would affect the protective effect. At the same time, the buffering properties of the flexible material can absorb the local impact force during the pressurization process, further protecting the polarization structure of the piezoelectric composite material from damage.

[0023] In some embodiments, the adaptive pressure control unit includes: a guide seat 5, a pressure sensor 6, a push rod 7, and a spring 8; One end of the top rod 7 is fixedly connected to the bottom end face of the cover plate 2; The bottom of the guide seat 5 is fixedly connected to the top end face of the base 1; The top end face of the guide seat 5 is provided with a first deep hole and a second deep hole; The diameter of the first deep hole is greater than the diameter of the second deep hole, the depth of the first deep hole is greater than the depth of the second deep hole, and the first deep hole and the second deep hole are concentrically arranged; The diameter of the second deep hole is larger than the diameter of the push rod 7, and the other end of the push rod 7 is located inside the first deep hole; The pressure sensor 6 is disposed at the top of the second deep hole, and the pressure sensor 6 is connected to the computer; The spring 8 is sleeved on the top rod 7 above the pressure sensor 6.

[0024] When the cover plate moves down, it causes the push rod to move down, compressing the spring. The pressure sensor sends the pressure from the spring to the computer in real time.

[0025] One end of the push rod is welded to the bottom end face of the cover plate, and the other end is inserted into the first deep hole of the guide seat, with a gap of ≤0.05mm between the push rod and the inner wall of the first deep hole, to ensure smooth up and down movement of the push rod without jamming; the depth of the first deep hole at the top of the guide seat is set to 15-20mm, and the depth of the second deep hole is set to 8-10mm to meet the installation and signal acquisition requirements of the pressure sensor; the spring is made of stainless steel with a stable elastic coefficient, and can assist the pressure sensor in capturing subtle pressure changes through compression deformation when the cover plate is pressed. The pressure data is converted into an electrical signal by the sensor and transmitted to the computer to achieve precise control of the pressure.

[0026] In some embodiments, the positioning mechanism includes: a positioning pin 9, a pressing column 10, a drive rod 11, and a pressure plate 12; At least three positioning pins 9 are provided and distributed in a circumferential direction on the top end face of the base 1. Correspondingly, the cover plate 2 is provided with through holes adapted to the positions of the positioning pins 9, and the upper end of the positioning pins 9 passes through the through holes. At least three pressing posts 10 are provided, and they are distributed in a circumferential direction on the top end face of the cover plate 2, and their positions are different from those of the through holes; One end of the drive rod 11 is rotatably connected to the center of the top end face of the cover plate 2; The pressure plate 12 is sleeved on the drive rod 11, and a groove is provided on the bottom end face of the pressure plate 12 that is adapted to the position of the pressing column 10.

[0027] The system includes three locating pins, evenly distributed in a 120° circle on the top surface of the base, with a clearance of ≤0.03mm between them and the through holes in the cover plate, ensuring accurate relative positioning between the base and the cover plate and preventing assembly misalignment. Three pressing columns are also included, staggered circumferentially distributed with the locating pins. Their top surfaces are arc-shaped to fit the arc-shaped inner wall of the pressure plate groove, reducing localized wear when the pressure plate is pressed down. The drive rod is connected to the top center of the cover plate using a bearing, with a rotational resistance of ≤5N, facilitating manual or mechanical movement of the pressure plate. Through the cooperation between the pressure plate groove and the pressing columns, pressure is evenly transmitted to the cover plate, achieving stable pressure application to the component.

[0028] Example 2 This application provides a method for assembling piezoelectric composite material components. The method is implemented based on a piezoelectric composite material component assembly fixture, wherein the fixture is equipped with an adaptive pressure linkage system that can dynamically match the cover plate pressure and the downward pressure distance according to the material and structure of the assembly components. The method includes the following steps: Step 1: Clean the surfaces of the piezoelectric composite material and the metal welding sheet to be bonded to meet the bonding requirements; First, use a sulfur-free eraser to remove surface stains, then soak it in an enamel pan filled with anhydrous ethanol for 10 minutes. Clean the surface and sides with a brush, then place it in an enamel pan lined with filter paper and dry it in an oven at (40±3)℃ for 20 to 30 minutes to ensure that the surfaces to be bonded are free of oil and impurities. Step 2: Prepare a pre-strength adhesive, apply it, and then bond the two together to form an assembly component; E-51 epoxy resin, dibutyl phthalate diluent, and 2-ethyl-4-methylimidazolium curing agent are weighed using a balance in a ratio of 20:1:1. The E-51 epoxy resin is first heated at (60±5)℃ for 10-20 minutes, then the diluent is added and stirred evenly, and then heated and kept at the temperature again. Finally, the curing agent is added and stirred evenly (the adhesive should be free of bubbles). The mixture should be prepared within 2 hours before assembly to ensure fluidity. After coating, the two are bonded together to form an assembly component. Step 3: Place the component in the tooling cavity and protect it with the protective mechanism. After closing the cover plate, fix it in place. Collect the component characteristics through the adaptive pressure linkage system, calculate the pressure and downward pressure distance reference, preset the control parameters and phased strategies, and collect pressure data. Step 4: Compare the real-time pressure with the preset benchmark pressure, and dynamically adjust the pressing distance of the cover plate in combination with the component curing deformation to optimize the control efficiency and stability in stages; during this process, an early warning is triggered, and the adhesive is set to be cured after the early warning is lifted, and then demolded after cooling.

[0029] After the warning is triggered, the components and the workpiece are cured in an oven at (80±1)℃ for 8 hours. After the warning is lifted, the components are allowed to cool naturally to room temperature and then demolded. In some embodiments, in step 3, different coefficients are used for different material components when calculating the pressure and downward pressure distance base. If the assembly component is a rigid piezoelectric composite material, the pressure reference should be 0.3 to 0.5 MPa, and the pressure distance reference coefficient should be 0.8 to 0.9. If it is a flexible piezoelectric composite material, the pressure reference is 0.1 to 0.3 MPa, and the pressure distance reference coefficient is 0.9 to 1.0. When the real-time pressure approaches 90% of the baseline upper limit, the control rate is reduced by 50%. When collecting component characteristics, an adaptive collection method is used for components of different sizes. If the component is a miniature piezoelectric element, the thickness is collected by a laser thickness gauge and the local hardness is collected by a microhardness tester. For large piezoelectric components, a multi-point data acquisition method should be used; Thickness sampling points ≥ 5, hardness sampling points ≥ 6, and the average value is taken as the characteristic parameter; When setting preset adjustment parameters, adjust them based on the adhesive type; If thermosetting adhesives are used, the allowable range of pressure fluctuations during the curing stage is reduced to ±5%, and the feedback frequency is increased to 3-4 Hz; If room temperature curing adhesive is used, the adjustment parameters should be kept within a fluctuation range of ±10%, and the pressure maintenance time should be extended by 1 to 2 hours at the end of the curing period.

[0030] When calculating the pressure and downward pressure distance references, different coefficients are used for components made of different materials: if the assembled component is a rigid piezoelectric composite material (used in high-frequency bandwidth transducers), the pressure reference is 0.3–0.5 MPa, and the downward pressure distance reference coefficient is 0.8–0.9; if it is a flexible piezoelectric composite material (suitable for complex marine environments), the pressure reference is 0.1–0.3 MPa, and the downward pressure distance reference coefficient is 0.9–1.0; when the real-time pressure approaches 90% of the upper limit of the reference, the control rate is reduced by 50% to avoid damage to the component from a sudden pressure surge; when collecting component characteristics, an adaptive collection method is used for components of different sizes: if it is a miniature piezoelectric element (size ≤10mm), a collection method with an accuracy of 0.01mm is used. Thickness is collected using a laser thickness gauge, and local hardness is collected using a microhardness tester with a 200g load. For large piezoelectric components (size > 50mm), a multi-point acquisition method is used, with ≥5 thickness acquisition points (uniformly distributed on the component surface) and ≥6 hardness acquisition points (including edge and center areas), and the average value is taken as the characteristic parameter. When preset adjustment parameters, adjustments are made based on the adhesive type: if thermosetting adhesives (such as E-51 epoxy resin system) are used, the allowable pressure fluctuation range during the curing stage is reduced to ±5%, and the feedback frequency is increased to 3-4Hz to ensure real-time pressure correction; if room temperature curing adhesives are used, the adjustment parameters retain a fluctuation range of ±10%, and the pressure maintenance time is extended by 1-2 hours at the end of the curing stage to ensure bonding strength.

[0031] In some embodiments, in step 3, when preset adjustment parameters, pressure-deformation-protection dynamic adaptation logic is constructed based on the material deformation coordination data collected in real time by the adaptive pressure linkage system. When collecting component characteristics, the adaptive pressure linkage system simultaneously records the elastic deformation curve of the piezoelectric composite material under a preset pressure. If the curve shows nonlinear fluctuations, it is determined that there is local stress concentration in the material, and the circumferential pressure distribution of the positioning and fastening mechanism is automatically adjusted. When the components are piezoelectric composite materials and metal sheets of different materials, the system formulates a temperature difference compensation coefficient in the pressure reference based on the difference in the thermal expansion coefficients of the two materials. If the ambient temperature difference is greater than 5°C in the subsequent curing stage, the adaptive system automatically adjusts the downward pressure distance according to the temperature difference compensation coefficient.

[0032] Specifically, when setting the control parameters, the system constructs a dynamic adaptation logic of pressure-deformation-protection based on the material deformation coordination data collected in real time by the adaptive pressure linkage system. When collecting component characteristics, the adaptive pressure linkage system records the elastic deformation curve of the piezoelectric composite material under the preset pressure every 10 seconds. If the curve shows nonlinear fluctuations (such as a sudden increase of 20% in deformation increment), it determines that there is local stress concentration in the material and automatically adjusts the circumferential pressure distribution of the positioning and fastening mechanism (such as fine-tuning the positioning pins in areas with excessive pressure to reduce local pressure). When the component is a piezoelectric composite material and metal welded sheets of different materials, the system uses the difference in their thermal expansion coefficients (e.g., the thermal expansion coefficient of the piezoelectric composite material is 10 × 10⁻⁶). -6 / ℃, the coefficient of thermal expansion of the metal solder sheet is 15×10. -6 / ℃), configure the temperature difference compensation coefficient in the pressure reference (each temperature difference corresponds to a 0.02mm downward pressure distance adjustment). If the ambient temperature difference in the subsequent curing stage is >5℃, the adaptive system will automatically adjust the downward pressure distance according to the temperature difference compensation coefficient to avoid bonding gaps caused by temperature differences.

[0033] In some embodiments, in step 4, the pressure regulation process needs to form a linkage intervention logic with the monitoring of adhesive rheological properties to achieve the prediction and dynamic correction of abnormal risks. While collecting real-time pressure, the adaptive pressure control unit indirectly monitors the rheological resistance of the adhesive through feedback from the gap between the push rod and the guide seat: if the resistance value increases by more than 30% within 10 seconds, it is determined that the adhesive is mixed with impurities or locally cured too quickly. The system immediately triggers the positioning and fastening mechanism to perform micro-loosening or rapid tightening action, while driving the pressing column on the cover plate to generate high-frequency micro-vibration. If the resistance value remains below 60% of the reference range, it is determined that the adhesive coating is insufficient. The system automatically calls the ejector hole at the bottom of the receiving cavity and blows the spare adhesive reserved on the side wall of the receiving cavity to the area lacking adhesive through a small amount of airflow. After the adhesive is replenished, the pressure control is restored.

[0034] The pressure control process needs to be linked with the monitoring of adhesive rheological properties to achieve the prediction and dynamic correction of abnormal risks. While collecting real-time pressure, the adaptive pressure control unit indirectly monitors the rheological resistance of the adhesive by changing the gap between the push rod and the guide seat (each 0.01mm change in gap corresponds to a 5% change in rheological resistance). If the resistance value increases by more than 30% within 10 seconds, it is determined that the adhesive is mixed with impurities or that local curing is too fast. The system immediately triggers the positioning and fastening mechanism to loosen it by 0.1-0.2mm, or drives the pressing column on the cover plate to generate a high-frequency micro-vibration of 50-100Hz to promote the dispersion of impurities and the uniform flow of adhesive. If the resistance value is consistently lower than 60% of the reference range, it is determined that the amount of adhesive applied is insufficient. The system automatically calls the ejector hole at the bottom of the receiving cavity and blows the spare adhesive (0.5-1ml pre-injected) reserved on the side wall of the receiving cavity to the area lacking adhesive through a micro-airflow of 0.1MPa. After the adhesive is replenished, the pressure control is restored to ensure that the adhesive layer on the bonding surface is uniform.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piezoelectric composite material component assembly fixture, characterized in that, include: The base is used to support the piezoelectric composite material components to be assembled. The top end face of the base is provided with a receiving cavity for accommodating the piezoelectric composite material component to be assembled. A cover plate, located above the base, is used to cooperate with the base to apply pressure to the component to be assembled; The positioning and fastening mechanism has its two ends connected to the base and the cover plate respectively. The distance between the cover plate and the base can be adjusted by operating the positioning and fastening mechanism. An adaptive pressure control unit, connected to an external computer, is located between the base and the cover plate and is connected to the top end face of the base. It is used to detect the pressure applied by the cover plate to the component to be assembled in real time.

2. The piezoelectric composite material component assembly fixture according to claim 1, characterized in that, The receiving cavity is a cylindrical cavity, and a through ejection hole is provided on the bottom of the receiving cavity; A circular groove coaxial with the receiving cavity is provided on the bottom end face of the cover plate; The circular groove and the receiving cavity are provided with protective mechanisms to protect the components to be assembled during the assembly process.

3. The piezoelectric composite material component assembly fixture according to claim 2, characterized in that, The protective mechanism includes: an upper protective pad and a lower protective pad; The upper protective pad is disposed in the circular groove during use, and the lower protective pad is disposed in the receiving cavity during use; both the upper and lower protective pads are made of flexible material. The upper protective pad and the lower protective pad have the same thickness.

4. The piezoelectric composite material component assembly fixture according to claim 1, characterized in that, The adaptive pressure control unit includes: a guide seat, a pressure sensor, a push rod, and a spring; One end of the top rod is fixedly connected to the bottom end face of the cover plate; The bottom of the guide seat is fixedly connected to the top end face of the base; The top end face of the guide seat is provided with a first deep hole and a second deep hole; The diameter of the first deep hole is greater than the diameter of the second deep hole, the depth of the first deep hole is greater than the depth of the second deep hole, and the first deep hole and the second deep hole are concentrically arranged; The diameter of the second deep hole is larger than the diameter of the push rod, and the other end of the push rod is located inside the first deep hole; The pressure sensor is disposed at the top of the second deep hole and is connected to the computer; The spring is sleeved on the top rod above the pressure sensor.

5. The piezoelectric composite material component assembly fixture according to claim 1, characterized in that, The positioning mechanism includes: a positioning pin, a pressing column, a drive rod, and a pressure plate; At least three positioning pins are provided and distributed in a circumferential direction on the top end face of the base. Correspondingly, the cover plate is provided with through holes adapted to the positions of the positioning pins, and the upper end of the positioning pin passes through the through hole. At least three pressing posts are provided, and they are distributed in a circumferential direction on the top end face of the cover plate, and their positions are different from those of the through holes; One end of the drive rod is rotatably connected to the center of the top end face of the cover plate; The pressure plate is sleeved on the drive rod, and a groove is provided on the bottom end face of the pressure plate to match the position of the pressing column.

6. A method for assembling piezoelectric composite material components, characterized in that, The piezoelectric composite material component assembly fixture according to any one of claims 1 to 5 is provided, wherein the fixture is equipped with an adaptive pressure linkage system, which can dynamically match the cover plate pressure and the pressing distance according to the material and structure of the assembly components; the method includes the following steps: Step 1: Clean the surfaces of the piezoelectric composite material and the metal welding sheet to be bonded to meet the bonding requirements; Step 2: Prepare a pre-set strength adhesive, apply it, and then bond the two together to form an assembly component; Step 3: Place the component in the tooling cavity and protect it with the protective mechanism. After closing the cover plate, fix it in place. Collect the component characteristics through the adaptive pressure linkage system, calculate the pressure and downward pressure distance reference, preset the control parameters and phased strategies, and collect pressure data. Step 4: Compare the real-time pressure with the preset benchmark pressure, and dynamically adjust the pressing distance of the cover plate in combination with the component curing deformation to optimize the control efficiency and stability in stages; during this process, an early warning is triggered, and the adhesive is set to be cured after the early warning is lifted, and then demolded after cooling.

7. The assembly method for piezoelectric composite material components according to claim 6, characterized in that, In step 3, different coefficients are used for different material components when calculating pressure and downward distance: If the assembly component is a rigid piezoelectric composite material, the pressure reference should be 0.3 to 0.5 MPa, and the pressure distance reference coefficient should be 0.8 to 0.

9. If it is a flexible piezoelectric composite material, the pressure reference is 0.1 to 0.3 MPa, and the pressure distance reference coefficient is 0.9 to 1.

0. When the real-time pressure approaches 90% of the baseline upper limit, the control rate is reduced by 50%.

8. When collecting component characteristics, adopt an adaptive collection method for components of different sizes; If the component is a miniature piezoelectric element, the thickness is collected by a laser thickness gauge and the local hardness is collected by a microhardness tester. For large piezoelectric components, a multi-point data acquisition method should be used; Thickness sampling points ≥ 5, hardness sampling points ≥ 6, and the average value is taken as the characteristic parameter; When setting preset adjustment parameters, adjust them based on the adhesive type; If thermosetting adhesives are used, the allowable range of pressure fluctuations during the curing stage is reduced to ±5%, and the feedback frequency is increased to 3-4 Hz; If room temperature curing adhesive is used, the adjustment parameters should be kept within a fluctuation range of ±10%, and the pressure maintenance time should be extended by 1 to 2 hours at the end of the curing period.

9. The assembly method for piezoelectric composite material components according to claim 6, characterized in that, In step 3, when setting the control parameters, a dynamic adaptation logic of pressure-deformation-protection is constructed based on the material deformation coordination data collected in real time by the adaptive pressure linkage system. When collecting component characteristics, the adaptive pressure linkage system simultaneously records the elastic deformation curve of the piezoelectric composite material under a preset pressure. If the curve shows nonlinear fluctuations, it is determined that there is local stress concentration in the material, and the circumferential pressure distribution of the positioning and fastening mechanism is automatically adjusted. When the components are piezoelectric composite materials and metal sheets of different materials, the system configures a temperature difference compensation coefficient in the pressure reference based on the difference in the thermal expansion coefficients of the two materials. If the ambient temperature difference is greater than 5°C during the subsequent curing stage, the adaptive system automatically adjusts the downward pressure distance according to the temperature difference compensation coefficient.

10. The assembly method for piezoelectric composite material components according to claim 6, characterized in that, In step 4, the pressure control process needs to be linked with the monitoring of adhesive rheological properties to form a coordinated intervention logic, so as to realize the prediction and dynamic correction of abnormal risks. While collecting real-time pressure, the adaptive pressure control unit indirectly monitors the rheological resistance of the adhesive through feedback from the gap between the push rod and the guide seat: if the resistance value increases by more than 30% within 10 seconds, it is determined that the adhesive is mixed with impurities or locally cured too quickly. The system immediately triggers the positioning and fastening mechanism to perform micro-loosening or rapid tightening action, while driving the pressing column on the cover plate to generate high-frequency micro-vibration. If the resistance value remains below 60% of the reference range, it is determined that the adhesive coating is insufficient. The system automatically calls the ejector hole at the bottom of the receiving cavity and blows the spare adhesive reserved on the side wall of the receiving cavity to the area lacking adhesive through a small amount of airflow. After the adhesive is replenished, the pressure control is restored.

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