Piezoelectric sensor and road weight measurement system

Abstract

The utility model discloses a piezoelectric sensor and road surface measuring weight system, the sensor includes shell, piezoelectric wafer element, is provided with the accommodation space in the shell, the both sides of accommodation space are equipped with the contact portion of parallel arrangement, the piezoelectric sensing element includes the locating member of inserting in the accommodation space, the conductive sheet is inserted in the locating member, the upper portion and the lower portion of conductive sheet all are equipped with a plurality of through the locating member positioning sensitive element, and every two sensitive element position of the vertical direction of conductive sheet corresponds, and the overboard for bearing is inserted between sensitive element and contact portion, and the overboard is connected with sensitive element through the conductive layer. The utility model discloses the shell is integral type aluminum alloy design, and the force of shell acts on quartz piezoelectric crystal through the overboard, and there is the conductive sheet between two quartz piezoelectric crystals of the same position, due to the shell, the overboard usually adopts the steel sheet and the strength of quartz piezoelectric crystal is higher, and the life of whole sensor is longer.

Description

Technical Field

[0001] This utility model belongs to the field of vehicle weighing technology, specifically, it relates to a piezoelectric sensor and a road weighing system. Background Technology

[0002] Overloaded vehicles pose a serious threat to the safety of road structures. They subject road surfaces and bridges to loads exceeding their design limits, leading to a significant increase in fatigue stress and accelerating the accumulation of fatigue damage in highway and bridge structures. This damage is gradual and irreversible, and may eventually result in serious problems such as cracks and fractures in highways and bridges. Therefore, effective measures must be taken to monitor and prevent overloaded vehicles from passing through sections of road before they cross bridges.

[0003] To achieve this goal, piezoelectric sensors and road weighing systems are widely used in vehicle weight measurement. These sensors operate based on the piezoelectric effect, which refers to the generation of electrical charges on the surface of a locating component when subjected to mechanical stress. When a vehicle passes the sensor, its weight exerts a downward force on the sensor. This force is transmitted to the piezoelectric element through the sensor's force-bearing structure. The generated charge is collected by electrodes and converted into an electrical signal (voltage or charge signal). This electrical signal is converted into a digital signal by an analog-to-digital converter, then processed by a microprocessor to ultimately calculate the weight of the object.

[0004] The piezoelectric sensor and road weighing system are ingeniously and complexly designed. Internally, the components utilize double-layered conductive sheets as positive and negative electrodes, with multiple quartz crystal plates arranged between these layers to achieve the weighing function. Externally, the sensor is protected by a robust aluminum alloy shell coated with epoxy resin and elastic materials on both sides, and is embedded in the ground to bear vehicle weight. An insulating barrier layer is placed between the aluminum alloy shell and a transition plate to prevent electrical short circuits and ensure the internal components are protected from external interference.

[0005] However, in practical applications, while the aluminum alloy casing can withstand most of the weight and pressure, the sensor's internal components still face some challenges. In existing quartz piezoelectric sensors, the insulating layer is repeatedly subjected to pressure and impact during use, causing the impedance to gradually decrease and the signal-to-noise ratio to gradually decline. After a certain period, the sensor becomes unable to collect effective data and fails. This signal interference can lead to inaccurate measurement data, severely affecting the accuracy, stability, and reliability of vehicle weight detection. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a piezoelectric sensor and a road weighing system.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this utility model includes: A piezoelectric sensor includes a housing and a piezoelectric sensing element. The housing has a receiving space inside, and parallel contact portions are provided on both sides of the receiving space. The piezoelectric sensing element includes a positioning component inserted into a receiving space, a conductive sheet inserted into the positioning component, and multiple sensitive elements positioned by the positioning component on both the upper and lower parts of the conductive sheet, with each pair of sensitive elements in the vertical direction of the conductive sheet corresponding to each other. A load-bearing transition plate is inserted between the sensitive element and the contact portion; the transition plate is connected to the sensitive element through a conductive layer.

[0008] Preferably, in the aforementioned piezoelectric sensor, the radial cross-section of the transition plate used for connecting with the housing is a planar or arc-shaped surface.

[0009] Preferably, in the aforementioned piezoelectric sensor, the sensitive element is a quartz piezoelectric crystal.

[0010] Preferably, in the aforementioned piezoelectric sensor: the housing is an integral aluminum alloy profile; the upper and lower sides of the housing are parallel support parts; when the piezoelectric sensor is installed on the road surface, the support parts and the contact parts are both parallel to the road surface.

[0011] Preferably, in the aforementioned piezoelectric sensor: a mounting groove for inserting a conductive sheet is provided in the middle of the component, and multiple connection holes for placing sensitive elements are provided through the positioning component. The connection holes are connected to the interior of the mounting groove, and the multiple sensitive elements are respectively installed at both ends of the connection holes at corresponding positions.

[0012] Preferably, in the aforementioned piezoelectric sensor, the two sides of the housing are receiving cylinders with a circular arc cross-section.

[0013] Preferably, the aforementioned piezoelectric sensor has an outer casing with a wrapping layer, which includes a polishing layer on the upper surface and an elastic layer on other surfaces.

[0014] Preferably, in the aforementioned piezoelectric sensor, the conductive layer and the transition plate are designed separately, or the conductive layer is plated on the surface of the transition plate.

[0015] A road surface weighing system uses any of the aforementioned piezoelectric sensors. When two piezoelectric sensors are buried in the road surface, the two piezoelectric sensors are arranged in parallel and have overlapping areas, and the overlapping areas of the two piezoelectric sensors are connected in series.

[0016] Compared with the prior art, the advantages of this utility model include: The outer shell of this utility model is an integrated aluminum alloy design. The force of the outer shell is applied to the quartz piezoelectric crystal through the transition plate. There is a conductive sheet between two quartz piezoelectric crystals at the same position. Since the outer shell, transition plate and quartz piezoelectric crystal are usually made of steel plate and have high strength, and there is only one conductive sheet located in the middle position, it can be well protected, thus making the life of the entire sensor longer.

[0017] Compared to the existing technology that arranges conductive sheets on both sides of the conductive sheet and arranges an insulating layer between the conductive sheet and the outer shell, the present invention has only one conductive sheet and does not require an insulating layer between the conductive sheet and the outer shell, thus greatly extending its service life. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an overall schematic diagram of a piezoelectric sensor and road surface weighing system according to the present invention; Figure 2 This is a schematic diagram illustrating the explosion effect of a piezoelectric sensor according to this utility model. Figure 3 This is a schematic diagram of the planar connection structure in this utility model; Figure 4 This is a schematic diagram of the connection structure of the arc-shaped surface in this utility model.

[0020] Figure label: 1. Outer shell; 11. Supporting part; 12. Receiving cylinder; 14. Contact part; 2. Piezoelectric sensing element; 21. Positioning component; 22. Conductive sheet; 23. Transition plate; 25. Sensing element; 26. Arc-shaped surface; 27. Mounting groove; 28. Connecting hole; 3. Conductive layer; 4. Elastic layer; 5. Abrasive layer; 21a-Side guard. Detailed Implementation

[0021] In view of the shortcomings of the prior art, the inventor of this utility model has, through long-term research and extensive practice, proposed the technical solution of this utility model. The following will further explain and illustrate the technical solution, its implementation process, and its principles in conjunction with the accompanying drawings and specific implementation examples.

[0022] It should be noted that the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, the present invention covers any substitutions, modifications, equivalent methods and solutions made within the spirit, principles and scope of the present invention as defined by the claims. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1 to 4 As shown, this embodiment discloses a piezoelectric sensor, including a housing 1 and a piezoelectric sensing element 2. The housing 1 has a receiving space; parallel contact portions 14 are provided on both sides of the receiving space; the piezoelectric sensing element 2 includes a positioning member 21 inserted into the receiving space, and a conductive sheet 22 is inserted into the positioning member 21. Multiple sensitive elements 25, positioned by the positioning member 21, are provided on both the upper and lower parts of the conductive sheet 22, and every two sensitive elements 25 in the vertical direction of the conductive sheet 22 correspond to each other. The sensitive element 25 is a quartz piezoelectric crystal.

[0024] A load-bearing transition plate 23 is inserted between the sensitive element 25 and the contact portion 14; the transition plate 23 is connected to the sensitive element 25 via a conductive layer 3. It should be noted that in this embodiment, the conductive layer 3 and the transition plate 23 are separate designs, or the conductive layer 3 is plated onto the surface of the transition plate 23. The transition plate 23 is typically a steel plate, used to distribute the force between the contact portion 14 and the conductive sheet 22. The radial cross-section of the transition plate 23 for connection with the outer casing 1 is a plane 24 or an arc-shaped surface 26. Figure 4 When using the curved surface 26, stress can be better dispersed, avoiding stress concentration, thereby improving the overall load-bearing capacity and service life of the sensor. The curved surface 26 performs better than the flat surface 24 in terms of explosion resistance and impact resistance, as it can disperse impact force over a larger area, reducing localized damage. The conductive layer 3 can use nickel strips from existing technologies.

[0025] Among them, the outer shell 1 is an integral aluminum alloy profile; the upper and lower sides of the outer shell 1 are parallel supporting parts 11, and the two sides of the outer shell 1 are receiving cylinders 12 with a circular arc cross section.

[0026] When the piezoelectric sensor is installed on the road surface, both the bearing part 11 and the contact part 14 are arranged parallel to the road surface.

[0027] The component 21 has a mounting groove 27 in the middle for inserting the conductive sheet 22. Multiple connecting holes 28 are provided through the positioning component 21 for inserting the sensitive element 25. The connecting holes 28 communicate with the interior of the mounting groove 27. Multiple sensitive elements 25 are respectively installed at both ends of the corresponding connecting holes 28. The positioning component 21 has baffles 21a on both sides. When it is inserted into the receiving space, the baffles 21a on both sides can lock the contact part 14 and the transition plate 23, thereby positioning the piezoelectric sensing element 2 inside the housing 1.

[0028] In use, the conductive sheet 22 and the outer shell 1 serve as two electrodes on both sides of the quartz piezoelectric crystal, with the outer shell 1 being the negative electrode and the conductive sheet 22 being the positive electrode.

[0029] Specifically, the supporting part 11 includes a contact part 14 integrally formed therewith, which contacts the transition plate 23. In this embodiment, the surface of the transition plate 23 that contacts the contact part 14 is a plane 24. The contact part 14 has a contact surface that is adapted to the shape of the plane 24. The contact part 14 contacts the plane 24 through the contact surface, and the width of the contact surface of the contact part 14 is equal to that of the plane 24.

[0030] In this embodiment, a wrapping layer is fixedly provided on both sides of the outer shell 1. The wrapping layer includes a grinding layer 5 on the upper surface and an elastic layer 4 on the other surfaces. The grinding layer 5 is used to directly contact the vehicle's tires. When the piezoelectric sensor is installed on the road surface, the grinding layer 5 can be polished to make the top surface of the piezoelectric sensor level with the surrounding road surface, avoiding any height difference between the piezoelectric sensor and the road surface after installation. This prevents the vehicle from jumping off the weighbridge and improves the detection accuracy of the piezoelectric sensor.

[0031] The elastic layer 4 is mainly made of PE foam material, which is used to ensure the fit between the sensor and the building surface and to prevent loosening.

[0032] from Figure 2 As can be seen, the conductive sheet 22 is assembled in the middle of the positioning component 21, while the quartz crystal is installed in the connecting hole 28. The top and bottom of the component 21 are then covered with transition plates 23, thus forming a piezoelectric sensing element 2. The piezoelectric sensing element 2 is then inserted into the receiving space inside the housing 1. The overall assembly structure has a very high space utilization rate, and the connection between the assembly structures is more snug. During production, due to the high dimensional correlation between multiple structures, dimensional errors during the production process can also be reduced.

[0033] In this embodiment, when the road surface is wide, the traditional installation of the piezoelectric sensor and the road weighing system involves connecting the ends of two piezoelectric sensors and the road weighing system together to form a straight line for real-time vehicle weighing. However, when the wheel is directly over the connection point of the two piezoelectric sensors and the road weighing system, data loss can easily occur, leading to a larger vehicle weighing error. To solve this technical problem, this embodiment proposes the following solution: This embodiment also discloses a road surface weighing system. When two piezoelectric sensors and the road surface weighing system are buried in the road surface, the two piezoelectric sensors and the road surface weighing system are arranged in parallel and have overlapping areas. The overlapping areas of the two piezoelectric sensors and the road surface weighing system are connected in series. The signals within the overlapping area can be shielded, avoiding the defects of inaccurate data caused by unstable signals at the ends of a single sensor, improving the measurement accuracy of dynamic vehicle weighing, and thus effectively intercepting overweight vehicles.

[0034] Compared with the prior art, this embodiment uses an integrated aluminum alloy profile as the outer shell 1. The two sides of the outer shell 1 are supported by arc-shaped receiving cylinders 12 to bear most of the road pressure, and only a very small force is transmitted to the conductive sheet 22, which greatly reduces the impact force of the vehicle on the conductive sheet 22 and improves the service life of the entire sensor.

[0035] In this embodiment, the outer shell 1 is a one-piece aluminum alloy design. The force of the outer shell 1 is applied to the quartz piezoelectric crystal through the transition plate 23. There is a conductive sheet 22 between the two quartz piezoelectric crystals at the same position. Since the outer shell 1, the transition plate 23 (usually made of steel plate) and the quartz piezoelectric crystal have high strength, and there is only one conductive sheet 22 located in the middle position, it can be well protected, thus making the life of the entire sensor longer.

[0036] Compared to the existing technology which arranges conductive sheets 22 on both sides of the conductive sheet 22 and arranges an insulating layer between the conductive sheet 22 and the outer shell 1, this embodiment has only one conductive sheet 22 and does not require an insulating layer between the conductive sheet 22 and the outer shell 1. Therefore, the service life of this embodiment will be greatly extended.

[0037] It should be understood that the above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. It should not be considered that the specific implementation of this utility model is limited to these descriptions. For those skilled in the art to which this utility model pertains, several simple deductions or substitutions can be made without departing from the concept of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A piezoelectric sensor, characterized in that, It includes a housing (1) and a piezoelectric sensing element (2), wherein the housing (1) has a receiving space; and the receiving space has parallel contact portions (14) arranged on both sides. The piezoelectric sensing element (2) includes a positioning member (21) inserted into the accommodating space. A conductive sheet (22) is inserted into the positioning member (21). Multiple sensitive elements (25) positioned by the positioning member (21) are provided on the upper and lower parts of the conductive sheet (22), and the positions of every two sensitive elements (25) in the vertical direction of the conductive sheet (22) are corresponding. A load-bearing transition plate (23) is inserted between the sensitive element (25) and the contact portion (14); the transition plate (23) is connected to the sensitive element (25) through a conductive layer (3).

2. A piezoelectric sensor according to claim 1, characterized in that: The radial section of the transition plate (23) used for connecting with the outer shell (1) is a plane (24) or an arc-shaped surface (26).

3. A piezoelectric sensor according to claim 1, characterized in that: The sensitive element (25) is a quartz piezoelectric crystal.

4. A piezoelectric sensor according to claim 1, characterized in that: The outer shell (1) is an integral aluminum alloy profile; the upper and lower sides of the outer shell (1) are parallel support parts (11); when the piezoelectric sensor is installed on the road surface, the support part (11) and the contact part (14) are both parallel to the road surface.

5. A piezoelectric sensor according to claim 1 or 4, characterized in that: The component (21) has a mounting groove (27) in the middle for inserting a conductive sheet (22). The positioning component (21) has multiple connecting holes (28) through which sensitive elements (25) are inserted. The connecting holes (28) are connected to the inside of the mounting groove (27). The multiple sensitive elements (25) are respectively installed at both ends of the connecting holes (28) at corresponding positions.

6. A piezoelectric sensor according to claim 1 or 4, characterized in that: The outer shell (1) has two sides of a receiving cylinder (12) with a circular arc cross-section.

7. A piezoelectric sensor according to any one of claims 1 to 4, characterized in that: The outer shell (1) is further provided with a wrapping layer, which includes an abrasive layer (5) disposed on the upper surface and an elastic layer (4) located on other surfaces.

8. A piezoelectric sensor according to claim 1, characterized in that: The conductive layer (3) and the transition plate (23) are either separate designs or the conductive layer (3) is plated on the surface of the transition plate (23).

9. A road surface weighing system, using the piezoelectric sensor according to any one of claims 1-8, characterized in that: When two piezoelectric sensors are buried in the road surface, the two piezoelectric sensors are arranged in parallel and have overlapping areas, and the overlapping areas of the two piezoelectric sensors are connected in series.

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