Manufacturing method of vehicle dynamic axle load monitoring sensor based on piezoelectric film and sensor

Abstract

The invention provides a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film and the sensor, and relates to the technical field of sensors, and the method comprises the steps: employing a conductive glue solution to enable a conductive lead to be installed at the short edge positions of the two surfaces of the piezoelectric film; epoxy resin sheets are mounted on two surfaces of the piezoelectric film; mounting rubber gaskets on the epoxy resin sheets on the two surfaces of the piezoelectric film; placing the piezoelectric film sensing element provided with the conductive lead, the epoxy resin sheet and the rubber gasket into a gap between an upper pressure applying structure and a lower pressure bearing structure of the circular packaging structure, and leading out the conductive lead from the lead leading-out through hole; the upper cover plate, the lower cover plate and the circular packaging structure are fixed through bolts, and a conductive lead is led out along a groove of the lower cover plate and is bonded and fixed; and waterproof sealing is performed after the circular packaging structure is jointed with the upper and lower cover plates. According to the method, the sensor and the road structure can form a good structural system, so that the monitoring precision and durability of the piezoelectric sensor are improved.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film and a sensor. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In order to ensure the safety of road traffic infrastructure under the load of heavy-loaded vehicles and improve road traffic safety, it is necessary to monitor and evaluate the axle load information of heavy-loaded vehicles, so as to crack down on illegal overloading, improve the efficiency of traffic law enforcement, and prevent damage to infrastructure caused by vehicle overloading. As an important part of the traffic monitoring system, the vehicle dynamic axle load monitoring sensor can monitor the axle load, speed, vehicle model and wheelbase of the vehicle while it is driving.

[0004] At present, the sensors commonly used for dynamic axle load monitoring of vehicles are resistive sensors and capacitive sensors. However, the above sensors have disadvantages such as low monitoring accuracy when the vehicle is driving at high speed, high cost and poor structural compatibility, and cannot be used for a long time in complex engineering service environments. Piezoelectric sensors are sensors made of new piezoelectric materials. Because of their good sensitivity and durability, they are gradually being used widely in the transportation industry. However, existing piezoelectric sensors have disadvantages such as low monitoring accuracy and poor durability. Therefore, high-precision and long-lasting axle load monitoring piezoelectric sensors have become a need of the industry.

[0005] The inventors found that most of the current piezoelectric sensor packaging structures and process materials focus too much on the piezoelectric performance of piezoelectric sensors, while there is little research on the monitoring accuracy and durability of embedded vehicle dynamic axle load monitoring piezoelectric sensors. The unscientific design of the sensor packaging structure will reduce the monitoring accuracy of the sensor, and at the same time, the compatibility with road and bridge structures will deteriorate, often causing problems such as damage to road and bridge structures and sensor destruction and deactivation, and the reliability of the sensor monitoring data cannot be guaranteed. Summary of the invention

[0006] The present application provides a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film and a sensor, which can form a good structural system between the sensor and the road structure to improve the monitoring accuracy and durability of the piezoelectric sensor.

[0007] In a first aspect, the present application provides a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film, the manufacturing method comprising:

[0008] Conductive silver glue is used to connect the piezoelectric film plated with electrodes with the conductive lead wire. After the conductive silver glue is cured, the epoxy resin sheet is attached to both sides of the piezoelectric film with glue liquid. After the glue liquid is cured, a self-adhesive rubber gasket is attached to the epoxy resin sheet to complete the production of a piezoelectric film sensor element.

[0009] Place multiple piezoelectric film sensor elements in the gap between the upper and lower cavities of the packaging structure in sequence, use glue to bond the piezoelectric film sensor elements to the packaging structure at the contact position, lead the conductive lead from the wire lead-out hole on the side of the packaging structure to the outside of the packaging structure, lead the conductive lead along the wire groove of the lower cover to the short side of the packaging structure, use glue to bond the wire to the groove and fill it until it is flush with the bottom surface of the lower cover, and after the glue solidifies, fix the upper and lower covers with bolts. After completion, the contact position between the piezoelectric film sensor element and the packaging structure, the bolt hole position and the wire lead-out hole are waterproof and sealed.

[0010] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film as described above, the packaging structure includes a circular packaging structure and an upper cover plate and a lower cover plate, the circular packaging structure has a cavity inside, and also has an upper pressure-applying structure and a lower pressure-bearing structure, the piezoelectric film sensor element is placed between the upper pressure-applying structure and the lower pressure-bearing structure to ensure that they are fully joined and then injected with glue for bonding and packaging; the upper cover plate and the lower cover plate are both polygonal structures, the upper cover plate, the lower cover plate and the circular packaging structure are all provided with bolt holes, the bolt holes are equidistantly arranged according to the arrangement conditions of the circular packaging structure, and the lower cover plate is provided with a wire groove for placing conductive leads.

[0011] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film as described above, the bolt holes set on the upper cover plate and the lower cover plate are through-going, and the bolt holes set on the circular packaging structure are not through-going. When joining, the upper cover plate and the lower cover plate are joined to the circular packaging structure by tightening the screws, and the gap at the joint is sealed with sealant.

[0012] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film as described above, the piezoelectric film sensor element is rectangular and plated with electrodes, and the conductive lead and the piezoelectric film are bonded with conductive glue.

[0013] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film as described above, the epoxy resin sheet and the rubber gasket are rectangular, and the epoxy resin sheet and the piezoelectric film sensor element are fixed with glue.

[0014] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film as described above, the circular packaging structure is made of insulating material, the piezoelectric film sensor element can be placed in the gap between the upper pressure structure and the lower pressure-bearing structure, the upper cover plate and the lower cover plate are both made of rigid material and are tightly fitted to the circular packaging structure, and the circular packaging structure is used to ensure that the piezoelectric film sensor element does not slip or rotate.

[0015] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film as described above, the wire lead-out hole is arranged on a side position of a long side of the circular packaging structure cavity.

[0016] Optionally, in the method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film as described above, the connection between the conductive lead and the piezoelectric film sensor element is coated with an insulating layer.

[0017] In a second aspect, the present application provides a vehicle dynamic axle load monitoring sensor based on a piezoelectric film, which is manufactured using the method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film as described in the first aspect of the present application.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The method of the present invention adopts a method of combining a piezoelectric film sensor element with a packaging structure to manufacture a piezoelectric sensor. The material of the packaging structure can be set according to the asphalt concrete of the road surface, so that the piezoelectric sensor and the road surface structure form a good structural system, which can not only make the piezoelectric film have a good insulation environment and a sealing environment, but also make the structural modulus of the sensor adapt to the modulus of different road surface structures, so that the data of vehicle dynamic axle load monitoring is more accurate and the durability of the sensor is better.

[0020] 2. The method of the present invention can improve the monitoring accuracy of the piezoelectric film through the cavity-type circular packaging structure, and can minimize the reduction and delay of the monitoring data output. By installing epoxy resin sheets and rubber gaskets on both sides of the piezoelectric film, it can effectively solve the problem of the piezoelectric film being damaged when subjected to heavy vehicle loads, thereby causing the sensor to become inactive.

[0021] 3. Compared with the full-coverage sensor structure, the method of the present invention saves the cost of piezoelectric film and packaging materials. The piezoelectric film sensor is easier to manufacture and will not slip during use. It is suitable for different types of piezoelectric film packaging, which expands the scope and field of application of piezoelectric film axle load sensors.

[0022] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] Figure 1 A flowchart of a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of assembling a plurality of packaged piezoelectric film sensor elements and a packaging structure provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of the assembly of a single packaged piezoelectric film sensor element and a packaging structure provided in an embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of the assembly of the piezoelectric film sensor element provided in an embodiment of the present application.

[0028] Description of reference numerals:

[0029] 1. Upper cover; 2. Lower cover; 3. Bolts; 4. Bolt holes; 5. Circular packaging structure; 5-1. Internal cavity; 5-2. Upper pressure-applying structure; 5-3. Lower pressure-bearing structure; 6. Wire groove; 7. Through hole; 8. Piezoelectric film sensor element; 8-1. Rubber gasket; 8-2. Epoxy resin sheet; 8-3. Piezoelectric film; 9. Conductive lead.

[0030] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0031] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0032] At present, there are few studies on the monitoring accuracy and durability of embedded piezoelectric sensors for monitoring dynamic axle loads of vehicles. Unscientific design of the sensor packaging structure will reduce the monitoring accuracy of the sensor. At the same time, the compatibility with road and bridge structures will deteriorate, often causing problems such as damage to road and bridge structures and sensor destruction and deactivation, and the reliability of the sensor monitoring data cannot be guaranteed. To address the above problems, the embodiments of the present application propose a method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film and a sensor.

[0033] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0034] like Figure 1-4 As shown, this embodiment provides a method for manufacturing a vehicle dynamic axle load monitoring sensor based on a piezoelectric film, and the manufacturing method specifically includes: installing an epoxy resin sheet 8-2 and a rubber gasket 8-1 on a piezoelectric film 8-3 with conductive leads 9 installed on both sides to complete the manufacturing of a piezoelectric film sensor element 8, sequentially placing a plurality of piezoelectric film sensor elements 8 into the gap between an upper pressure-applying structure 5-2 and a lower pressure-bearing structure 5-3 of a circular packaging structure 5, bonding the circular packaging structure 5 and the piezoelectric film sensor element 8 with glue, and waiting for the piezoelectric film sensor element 8 to be formed. After the glue is solidified, the conductive lead 9 is led out along the through hole 7, and the circular packaging structure 5 is joined with the upper cover plate 1 and the lower cover plate 2 by fastening with bolts 3. The conductive leads 9 of all piezoelectric film sensor elements 8 are led out of the packaging structure along the wire groove 6 on the surface of the lower cover plate 2. The conductive lead 9 is bonded to the wire groove 6 with glue and filled until it is flush with the surface of the lower cover plate 2. After the glue is solidified, the glue is then used to waterproof and seal the joints between the through hole 7, the upper cover plate 1, the lower cover plate 2 and the circular packaging structure 5 and the bolt hole positions.

[0035] It should be noted that, in this embodiment, four piezoelectric film sensor elements are shown, but this does not constitute a limitation to the present application. In other embodiments, the specific number of piezoelectric film sensor elements can be set according to actual conditions.

[0036] The connection between the conductive lead 9 and the piezoelectric film 8 - 3 is coated with an insulating layer.

[0037] In this embodiment, the length and width of the epoxy resin sheet 8-2 and the rubber gasket 8-1 are the same as the size of the piezoelectric film. When the epoxy resin sheets are installed on both sides of the piezoelectric film, the epoxy resin sheets can be tightly attached to the piezoelectric film. The epoxy resin sheet and the piezoelectric film are bonded with glue to prevent the sensor output performance from being reduced due to loose fitting.

[0038] In this embodiment, the circular packaging structure is a circular structure with a cavity inside, the upper and lower cover plates are polygonal structures, the size of the piezoelectric film is slightly smaller than the circular packaging structure 5, and the length and width range of the circular packaging structure is: long side 50mm-80mm, short side 10mm-20mm. As an example only, the circular packaging structure is made of nylon material, and the upper and lower cover plates are made of stainless steel. The materials for making the circular packaging structure and the upper and lower cover plates are configured to be reliably bonded with the glue to ensure that the sensor is firm and stable.

[0039] In some embodiments, the circular packaging structure is provided with an internal cavity 5-1, an upper pressure-applying structure 5-5 and a lower pressure-bearing structure 5-3, the internal packaging structure is made of an insulating material, the piezoelectric film sensor element 8 can be placed in the gap between the upper pressure-applying structure 5-2 and the lower pressure-bearing structure 5-3, and the contact position between the packaging structure and the piezoelectric film sensor element is bonded by glue;

[0040] In some embodiments, a through hole 7 is provided on one of the long side walls of the circular packaging structure cavity for leading out the conductive lead 9. As an example only, the diameter of the through hole ranges from 2 mm to 5 mm.

[0041] In some embodiments, the upper and lower cover plates are divided into an upper cover plate 1 and a lower cover plate 2. The lower cover plate 2 is provided with a wire groove 6 that runs through the entire cover plate along the long side direction of the cover plate, which is used to install the conductive lead 9 of the piezoelectric film sensor element 8. Preferably, the depth range of the wire groove is 3mm-5mm.

[0042] In this embodiment, the circular packaging structure 5 is made of a material having a modulus similar to that of the road structure and can ensure reliable bonding with the road structure. The packaging structure can ensure insulation and waterproofing, and can ensure that the piezoelectric film sensor element 8 does not slip or rotate.

[0043] In some embodiments, the circular packaging structure 5 can be well bonded with the upper cover plate 1 and the lower cover plate 2 without generating a large gap.

[0044] In some embodiments, the upper cover plate 1, the lower cover plate 2 and the circular packaging structure 5 are all provided with bolt holes 4 for upper and lower connection. The bolt holes of the upper and lower cover plates are through-through, while the bolt holes of the circular packaging structure are not through-through. A wire lead-out through hole 7 is provided along one side of the long side of the circular packaging structure 5. When connecting, the upper cover plate 1, the lower cover plate 2 and the circular packaging structure 5 are connected by tightening the bolts, and the gap at the connection is sealed with sealant.

[0045] In this embodiment, the conductive glue is conductive silver glue, and the viscosity and curing time of the glue system should be adapted to the installation process of the piezoelectric film sensor element.

[0046] In some embodiments, the system viscosity and curing time of the glue solution should be adapted to the installation process of joining the piezoelectric film sensor element and the circular structure to ensure the completion of the glue injection process.

[0047] In some embodiments, the glue used to bond the piezoelectric film with conductive leads installed to the epoxy resin sheet and the glue used to bond the piezoelectric film sensor element to the circular packaging structure is 502 glue or welding agent or super glue. The glue should be able to ensure that the piezoelectric film sensor element is tightly bonded to the circular packaging structure.

[0048] In some embodiments, the adhesive bonding the conductive lead and the wire groove is a strong adhesive.

[0049] In some embodiments, the sealant liquid is a glass waterproof sealant.

[0050] In some embodiments, the epoxy resin sheet is rectangular, and its length and width are the same as those of the piezoelectric film. The epoxy resin sheet and the piezoelectric film are bonded with glue.

[0051] In a specific embodiment, if Figure 1 As shown, the specific manufacturing steps of the vehicle dynamic axle load monitoring sensor based on piezoelectric film include steps 1 to 5, which are introduced in detail as follows.

[0052] Step 1: Install the conductive leads to one side of the short side of the piezoelectric film.

[0053] Specifically, the conductive lead is installed on the piezoelectric film by bonding with conductive glue, and the piezoelectric film itself is plated with electrodes.

[0054] Step 2: Install epoxy resin sheets and rubber gaskets on both sides of the piezoelectric film.

[0055] Specifically, glue is applied on both sides of the piezoelectric film with conductive leads installed, and then epoxy resin sheets are pasted to both sides of the film, and pressure is applied to make the epoxy resin sheet and the piezoelectric film fit tightly. After the glue is cured, a self-adhesive rubber gasket is pasted to the epoxy resin sheet.

[0056] Complete the production of four piezoelectric film sensor elements in sequence according to the above steps 1 and 2.

[0057] Step 3: Place the piezoelectric film sensor element with the conductive leads, epoxy resin sheet and rubber gasket installed in the circular packaging structure and bond it with glue.

[0058] Specifically, glue is applied to the surface of the upper pressure structure and the lower pressure-bearing structure of the circular packaging structure, the piezoelectric film sensor element is placed in the gap between the upper pressure structure and the lower pressure-bearing structure, and the conductive lead is led out through the through hole on the side of the circular packaging structure. After the glue is solidified, the glue is used to fill the gap at the joint of the piezoelectric film sensor element and the circular packaging structure. After the glue is injected, it is placed at the theoretical initial setting temperature of the glue for 2 hours to gel, and then placed at the curing temperature for more than 5 hours. The theoretical initial setting temperature and curing temperature of the glue are set according to the material of the packaging glue, which will not be described in detail here.

[0059] Step 4: Join the lower cover plate and the circular packaging structure by bolting, and draw the conductive leads of all piezoelectric film sensor elements along the wire groove to the outside of the packaging structure and fix them by bonding.

[0060] Specifically, the circular packaging structure is placed equidistantly, and then bolted to the lower cover, the upper cover is aligned with the circular packaging structure, and after tightening the bolts, the conductive leads of all piezoelectric film sensor elements are pulled along the wire groove to the outside of the packaging structure, and then the conductive leads are bonded to the wire groove with glue, and filled until it is flush with the surface of the lower cover, and the next step is carried out after the glue is cured.

[0061] Step 5: Join the upper cover plate and the circular packaging structure by bolting, and use sealant to waterproof the conductive lead outlet, the joints between the upper and lower cover plates and the circular packaging structure, and the bolt holes.

[0062] Specifically, the upper cover plate and the circular packaging structure are joined by bolt fastening, the upper cover plate and the circular packaging structure are aligned, the upper and lower bolt holes are aligned, and then the bolts are tightened to tightly join the upper cover plate and the circular packaging structure. Then, a sealing glue is used to waterproof the conductive lead outlet, the joint between the cover plate and the base, and the bolt position, which can effectively prevent water from entering the sensor, thereby ensuring the survival rate of the sensor. After the glue is cured, the entire sensor is completed.

[0063] The embodiment of the present application provides a vehicle dynamic axle load monitoring sensor based on piezoelectric film, which is manufactured by the method described in any of the above embodiments. The sensor of this embodiment is manufactured by combining a piezoelectric film sensor element with a packaging structure, has good load-bearing capacity and recovery performance, forms a good structural system, minimizes the reduction of the output performance of the piezoelectric sensor, and improves the monitoring accuracy. Under this premise, the packaging structure can not only prevent the piezoelectric film sensor element from slipping during use, but also make the structural modulus of the sensor adapt to the modulus of different road structures, thereby improving the durability of the sensor and reducing damage to the road structure.

[0064] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0065] It should be noted that the phrases "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0066] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0067] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0068] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film, characterized in that: The production method comprises: Conductive silver glue is used to connect the piezoelectric film plated with electrodes with the conductive lead wire. After the conductive silver glue is cured, the epoxy resin sheet is attached to both sides of the piezoelectric film with glue liquid. After the glue liquid is cured, a self-adhesive rubber gasket is attached to the epoxy resin sheet to complete the production of a piezoelectric film sensor element. Place multiple piezoelectric film sensor elements in the gap between the upper and lower cavities of the packaging structure in sequence, use glue to bond the piezoelectric film sensor elements to the packaging structure at the contact position, lead the conductive lead from the wire lead-out hole on the side of the packaging structure to the outside of the packaging structure, lead the conductive lead along the wire groove of the lower cover to the short side of the packaging structure, use glue to bond the wire to the groove and fill it until it is flush with the bottom surface of the lower cover, and after the glue solidifies, fix the upper and lower covers with bolts. After completion, the contact position between the piezoelectric film sensor element and the packaging structure, the bolt hole position and the wire lead-out hole are waterproof and sealed.

2. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 1, characterized in that: The packaging structure includes a circular packaging structure and an upper cover plate and a lower cover plate. The circular packaging structure has a cavity inside, and also has an upper pressure-applying structure and a lower pressure-bearing structure. The piezoelectric film sensor element is placed between the upper pressure-applying structure and the lower pressure-bearing structure to ensure that they are fully joined and then injected with glue for bonding and packaging. The upper cover plate and the lower cover plate are both polygonal structures. Bolt holes are provided on the upper cover plate, the lower cover plate and the circular packaging structure. The bolt holes are equidistantly arranged according to the arrangement conditions of the circular packaging structure. The lower cover plate is provided with a wire groove for placing conductive leads.

3. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 2, characterized in that: The bolt holes arranged on the upper cover plate and the lower cover plate are through-through, while the bolt holes arranged on the circular packaging structure are not through-through. When joining, the upper cover plate and the lower cover plate are joined to the circular packaging structure by tightening the screws, and the gap at the joint is sealed by using sealant.

4. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 1, characterized in that: The piezoelectric film sensor element is rectangular and plated with electrodes. The conductive lead and the piezoelectric film are bonded with conductive glue.

5. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 1, characterized in that: The epoxy resin sheet and the rubber gasket are rectangular, and the epoxy resin sheet and the piezoelectric film sensor element are fixed by glue.

6. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 2, characterized in that: The circular packaging structure is made of insulating material, and the piezoelectric film sensor element can be placed in the gap between the upper pressure-applying structure and the lower pressure-bearing structure. The upper cover plate and the lower cover plate are both made of rigid material and fit tightly with the circular packaging structure. The circular packaging structure is used to ensure that the piezoelectric film sensor element does not slip or rotate.

7. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 1, characterized in that: The wire lead-out hole is arranged on the side of the long side of the circular packaging structure cavity.

8. The method for manufacturing a vehicle dynamic axle load monitoring sensor based on piezoelectric film according to claim 1, characterized in that: The connection between the conductive lead and the piezoelectric film sensor element is coated with an insulating layer.

9. A vehicle dynamic axle load monitoring sensor based on piezoelectric film, characterized in that: The method is produced according to any one of claims 1 to 8.

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