Energy-saving excitation aggregate screening device

Abstract

The utility model discloses an energy -saving type excitation and stir aggregate screening device, including exciting device, piezoelectric device and piezoelectric tray, the exciting device includes the shell, and sets up the eccentric wheel in its inside, a plurality of piezoelectric devices set up in the shell and be located the rotation track of eccentric wheel, and piezoelectric device passes through piezoelectric excitation conversion output electric energy, the piezoelectric tray includes tray frame, screen disc, tray, piezoelectric layer and piezoelectric sensor, the tray frame is connected with eccentric wheel through conducting device, and a plurality of screen discs are stacked from top to bottom on the tray frame, and the tray is set up at the bottom of the last layer screen disc, and piezoelectric layer sets up in the tray, and piezoelectric layer produces piezoelectric excitation signal under the gravity of the aggregate screened by the last layer screen disc, and piezoelectric layer is connected with piezoelectric sensor, and control unit determines the screening completion time according to piezoelectric excitation signal, the device realizes the automatic identification of screening completion time and the self -power supply function, solves the problem, such as long, low efficiency, higher energy consumption of each round screening time in the real test process.

Description

Technical Field

[0001] This utility model relates to the field of road engineering equipment, specifically an energy-saving vibrating aggregate screening device. Background Technology

[0002] Currently, highway aggregate screening tests mainly rely on manual experience to determine the screening endpoint, i.e., the time it takes for screening to complete. Testers control the screening process based on experience and by using timed or manual shutdown methods. However, the screening machine's operating parameters, such as vibration frequency, amplitude, and duration, are mostly set based on recommended values ​​rather than real-time monitoring of the screening status. This results in the screening effect being heavily influenced by the operator's subjectivity. If the set time is too short, incomplete screening is likely. Therefore, to ensure sufficient screening, testers often use longer screening times, i.e., adding redundant time, which is not only inefficient but also wastes unnecessary energy. Existing screening equipment generally lacks intelligent monitoring methods and cannot dynamically identify the screening completion rate, resulting in poor screening quality stability. Furthermore, prolonged vibration may cause aggregate particles to break, affecting the accuracy of the test.

[0003] Based on the above-mentioned technical problems, this application designs a road aggregate screening machine based on piezoelectric technology. This road aggregate screening machine can be self-powered and can automatically identify the screening completion time and stop the machine autonomously, thereby improving the accuracy of the test and reducing energy consumption. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides an energy-saving vibrating aggregate screening device. This aggregate screening device is based on piezoelectric technology, realizes automatic identification of the screening completion time, and has a self-powered function, thus solving the drawbacks of long screening time, low efficiency, and high energy consumption in actual test processes.

[0005] This utility model is achieved through the following technical solution: An energy-saving vibrating aggregate screening device, characterized in that it includes a vibrating device, a piezoelectric device, and a piezoelectric tray; The excitation device includes a housing and an eccentric wheel disposed inside it. Multiple piezoelectric devices are disposed in the housing and located on the rotation trajectory of the eccentric wheel. During rotation, the eccentric wheel can apply compressive stress to the piezoelectric devices, and the piezoelectric devices can convert piezoelectric excitation into output electrical energy. The piezoelectric tray includes a tray frame, a sieve tray, a tray, a piezoelectric layer, and a piezoelectric sensor; The tray frame is connected to the eccentric wheel through a transmission device. Multiple screens are stacked on the tray frame from top to bottom. The tray is located at the bottom of the bottommost screen. The piezoelectric layer is located in the tray. The piezoelectric layer generates a piezoelectric excitation signal under the gravity of the aggregate screened off the bottommost screen. The piezoelectric layer is connected to the piezoelectric sensor. The excitation device and the piezoelectric sensor are respectively connected to the control unit. The control unit determines the screening completion time based on the piezoelectric excitation signal and controls the operation of the excitation device.

[0006] Preferably, the piezoelectric device includes a stacked piezoelectric unit, an actuator, and a pressure block; The stacked piezoelectric unit is fixed on the side wall of the housing. The bottom of the actuating section is connected to the housing through a displacement structure. One end of the actuating section is used to apply pressure to the stacked piezoelectric unit, and the other end of the actuating section is connected to the pressure block, which is located on the rotation trajectory of the eccentric wheel.

[0007] Preferably, the pressure plate is provided with an insulating actuation pad on the side near the stacked piezoelectric unit, and the side of the pressure block near the eccentric wheel is an arc-shaped surface, the curvature of which is less than the curvature of the circular trajectory of the eccentric wheel.

[0008] Preferably, the displacement structure is an elastic displacement structure or a sliding displacement structure.

[0009] Preferably, stacked piezoelectric units are respectively provided on both sides of the corner of the housing; The transmission joint includes a main actuator joint and a secondary actuator joint. One end of the two secondary actuator joints is connected to two pressure plates respectively, and the other end of the two secondary actuator joints is connected to a pressure block. The main actuator joint is located on the centerline between the included angles of the two secondary actuator joints. One end of the main actuator joint is connected to the end of the two pressure plates that are close to each other through an adapter arm, and the other end of the main actuator joint is connected to the middle of the pressure block.

[0010] Preferably, the eccentric wheel is provided with a trigger block, which is used to apply tangential pressure to the pressure block; The trigger block is a protruding structure or a roller located on the side wall of the eccentric wheel.

[0011] Preferably, the transmission device includes transmission rods and a base plate. With the center of the eccentric wheel as the midpoint, multiple transmission rods are evenly distributed around the eccentric wheel. The base plate is fixed to the upper end of the multiple transmission rods and is in a horizontal state. The pallet frame is fixed on the base plate.

[0012] Preferably, the piezoelectric layer is disposed in the tray, the piezoelectric sensor is fixed on the base plate, and the piezoelectric layer is pressed onto the piezoelectric sensor and electrically conductive.

[0013] Preferably, the sieve holes of the multiple sieve discs decrease in size from top to bottom.

[0014] Preferably, the top of the housing of the excitation device is provided with a plurality of infrared sensors in a ring. The infrared sensors are connected to the piezoelectric device, emit infrared light vertically upward, and are located outside the vibration range of the screen. The infrared sensors are connected to the control unit.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This application provides an energy-saving vibrating aggregate screening device. The vibrating device generates mechanical vibration through an eccentric wheel, providing a power source for screening. A piezoelectric device, located on the rotation trajectory of the eccentric wheel, converts mechanical vibration energy into electrical energy, achieving energy recovery. The piezoelectric tray integrates piezoelectric sensing functionality, monitoring the aggregate screening status in real time through the piezoelectric layer. This screening device, through the cooperation of the piezoelectric layer and piezoelectric sensors, can capture the aggregate screening status of the bottom screen in real time. When the piezoelectric excitation signal continuously disappears for a set time, the control unit can automatically determine that screening is complete and stop the machine, completely solving the problems of insufficient screening or time redundancy in traditional manual judgment methods, significantly improving screening accuracy and consistency. Secondly, the piezoelectric device converts the mechanical energy of the eccentric wheel rotation into electrical energy through the positive piezoelectric effect, not only achieving self-powered equipment and reducing dependence on external energy, but also powering the control system and sensors. Furthermore, the device adopts a compact integrated design for the vibrating device, energy recovery module, and screening tray. The mechanical connections and signal transmission between components are optimized, ensuring system stability and facilitating maintenance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an energy-saving vibrating aggregate screening device according to the present invention; Figure 2 This is a diagram showing the motion trajectory of the eccentric shaft of this utility model. Figure 3 This is a top view of the piezoelectric device of this utility model; Figure 4 This is a schematic diagram of the structure of the actuator of this utility model; In the diagram: 1. Vibration device; 2. Tray frame; 3. Piezoelectric tray; 4. Conducting device; 5. Piezoelectric device; 11. Controller; 12. Infrared sensor; 13. Lighting lamp; 21. Pressure plate; 22. Support rod; 23. Fastening nut; 24. Support. 31. Screen plate; 32. Tray; 41. Piezoelectric sensor; 42. Base plate; 43. Eccentric wheel; 44. Transmission rod; 45. Trigger block; 51. Actuating section; 52. Flexible rubber pad; 53. Insulating actuating pad; 54. Stacked piezoelectric unit; 55. Integrated piezoelectric capacitor; 56. Cable; 57. Secondary actuating section; 58. Main actuating section. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] See Figure 1-4 An energy-saving vibrating aggregate screening device includes a vibrating device 1, a piezoelectric device 5, and a piezoelectric tray 3; The excitation device 1 includes a housing and an eccentric wheel 43 disposed inside it. Multiple piezoelectric devices 5 are disposed in the housing and located on the rotation trajectory of the eccentric wheel 43. During rotation, the eccentric wheel 43 can apply compressive stress to the piezoelectric devices 5. The piezoelectric devices 5 convert piezoelectric excitation into output electrical energy. The piezoelectric tray includes a tray frame 2, a sieve tray 31, a tray 32, a piezoelectric layer, and a piezoelectric sensor 41; The tray frame 2 is connected to the eccentric wheel 43 through the transmission device 4. Multiple screens 31 are stacked on the tray frame 2 from top to bottom. The tray 32 is set at the bottom of the bottommost screen 31. The piezoelectric layer is set at the bottom of the tray 32. The piezoelectric layer generates a piezoelectric excitation signal under the gravity of the aggregate screened off the upper screen 31. The excitation device 1 and the piezoelectric sensor 41 are respectively connected to the control unit, and the control unit controls the completion time of screening according to the piezoelectric excitation signal.

[0025] In some embodiments, a drive motor is provided in the housing of the excitation device, the shaft of the eccentric wheel 43 is fixedly connected to the output shaft of the eccentric motor, the drive motor is connected to the control unit, the drive motor drives the eccentric wheel 43 to rotate, and the centrifugal force during rotation causes the screening machine to generate periodic vibration, which drives the screen plate 31 to perform periodic reciprocating vibration, thereby realizing the layer-by-layer screening of the aggregate in the screen plate 31.

[0026] Meanwhile, since multiple piezoelectric devices 5 are respectively arranged on the rotation trajectory of the eccentric wheel 43, the eccentric wheel 43 can periodically apply compressive stress to each piezoelectric device 5 during rotation, so that the piezoelectric device 5 generates electrical energy, and the generated electrical energy serves as the function of the entire vibrating aggregate screening device.

[0027] In some embodiments, the piezoelectric device 5 includes a stacked piezoelectric unit 54, an actuator 51, and a pressure block.

[0028] The stacked piezoelectric unit 54 is fixed on the side wall of the housing. The bottom of the actuator 51 is connected to the housing through a displacement structure. One end of the actuator 51 is in contact with the stacked piezoelectric unit 54, and the other end of the actuator 51 is connected to the pressure block. The pressure block is located on the track of the eccentric wheel 43. During the rotation of the eccentric wheel 43, the outer circle of the eccentric wheel 43 can exert a time tangential pressure on the pressure block, thereby causing the actuator 51 to be displaced. The end of the actuator 51 applies compressive stress to the stacked piezoelectric unit 54, and the stacked piezoelectric unit 54 generates and stores electrical energy.

[0029] The stacked piezoelectric unit 54 is composed of multiple layers of piezoelectric ceramic sheets, such as PZT material. Each ceramic sheet is coated with electrodes and connected in series with conductive adhesive or metal foil. Metal end plates are provided at both ends for power output. The whole unit is fixed by pre-tightened bolts to enhance tensile strength. The actuating section 51 and the pressure block mechanically link it with the eccentric wheel 43. When the eccentric wheel 43 rotates, it periodically squeezes the pressure block, causing the actuating section 51 to transmit axial pressure to the stacked unit.

[0030] Based on the positive piezoelectric effect, when the eccentric wheel 43 applies a tangential force to the pressure block, the actuator 51 transmits the pressure to the stacked piezoelectric unit 54. The piezoelectric ceramic sheets are axially compressed, causing charge separation and outputting an instantaneous current. After the eccentric wheel 43 disengages, the elastic displacement structure, such as a metal spring plate, resets the actuator 51, and the piezoelectric unit is relieved of stress. The currents from multiple ceramic sheets are superimposed and stored in the integrated piezoelectric capacitor 55 for the device's self-powered operation.

[0031] This design efficiently converts the vibrational mechanical energy of the screening machine into electrical energy, reducing the need for external power supply; the stacked structure increases the power generation density, while providing stable energy for lighting, sensors, etc., achieving energy saving and intelligent control.

[0032] Optionally, a pressure plate is provided at one end of the actuating segment near the stacked piezoelectric unit 54. The pressure plate faces the stacked piezoelectric unit 54 and has the same area as the stacked piezoelectric unit 54. When the actuating segment is displaced, the pressure plate applies pressure to the stacked piezoelectric unit 54. Since the area of ​​the pressure plate is the same as the area of ​​the stacked piezoelectric unit 54, the maximum actuating area can be applied to the stacked piezoelectric unit 54, so that the power generation efficiency of the stacked piezoelectric unit 54 can be maximized.

[0033] Furthermore, an insulating actuating pad 53 is provided on the side of the pressure plate near the stacked piezoelectric unit 54. The insulating actuating pad 53 applies pressure to the stacked piezoelectric unit 54. When the eccentric shaft separates from the pressure block, the insulating actuating pad 53 resets under the action of elasticity. That is, the insulating actuating pad 53 separates from the stacked piezoelectric unit 54, or only contacts it. It should be noted that when the insulating actuating pad 53 is in contact with the stacked piezoelectric unit 54, it does not apply pressure to the stacked piezoelectric unit 54, and the stacked piezoelectric unit 54 does not generate electrical energy.

[0034] The insulating actuating pad 53 is made of insulating rubber.

[0035] Furthermore, the side of the pressure block closest to the eccentric wheel 43 is an arc-shaped surface. During the rotation of the eccentric wheel 43, the side wall of the eccentric wheel 43 comes into contact with the arc-shaped surface to generate tangential pressure. The tangential pressure gradually increases and then gradually decreases after reaching its maximum value.

[0036] At the initial contact position, the tangential pressure of the eccentric wheel 43 on the arc surface is 0, and the actuator 51 does not produce displacement. As the eccentric wheel 43 continues to rotate, the tangential pressure on the arc surface gradually increases, that is, the displacement of the actuator 51 increases synchronously. When the displacement reaches its maximum, the eccentric wheel 43 gradually separates from the arc surface, the tangential pressure gradually decreases, and the actuator 51 resets until the eccentric wheel 43 is completely separated from the arc surface, that is, the insulating actuator pad 53 separates from the stacked piezoelectric unit 54, or only makes contact.

[0037] Furthermore, the curvature of the arc-shaped surface is less than the curvature of the circular trajectory of the eccentric wheel 43, thus avoiding collision between the eccentric wheel 43 and the end of the pressure block. This can also be understood as the diameter of the arc-shaped surface being greater than the diameter of the circular trajectory of the eccentric wheel 43. This design avoids the problem of collision between the eccentric wheel 43 and the end of the arc-shaped surface of the pressure plate. During the rotation of the eccentric wheel 43, by controlling the curvature of the arc-shaped surface, the maximum outer diameter position of the side wall of the eccentric wheel 43 enters the arc-shaped surface area and contacts it to apply pressure.

[0038] Furthermore, a flexible pad 52 is attached to the arc-shaped surface. The eccentric wheel 43 directly contacts the flexible pad 52 to apply pressure, reducing the noise during the contact process and avoiding wear on the eccentric wheel 43 and the arc-shaped surface during cyclic rotation, thereby improving the service life of the stacked piezoelectric unit 54.

[0039] In some embodiments, the displacement structure is an elastic displacement structure or a sliding displacement structure.

[0040] The elastic displacement structure includes a spring arm, which is vertically arranged. The upper end of the spring arm is fixedly connected to the bottom of the actuating section 51, and the lower end of the spring arm is connected to the bottom of the housing of the excitation device 1. When the eccentric wheel 43 applies tangential pressure to the pressure block, the spring arm deforms, and the actuating section 51 applies pressure to the stacked piezoelectric unit 54. When the eccentric wheel 43 separates from the pressure block, the spring arm resets, and the actuating section 51 separates and resets the stacked piezoelectric unit 54.

[0041] The elastic arm is either a metal plate or a spring.

[0042] The metal spring plate includes a fixed arm and a bent wall. The lower end of the fixed arm is fixed to the housing, and the lower end of the bent wall is connected to the upper end of the fixed arm. The upper end of the bent wall is inclined towards the eccentric wheel 43, and an angle is formed between the fixed arm and the bent wall. The fixed arm and the bent wall are integrally structured and manufactured by bending process. The metal spring plate is made of elastic steel, which produces a spring-like effect when moving. When the moving joint 51 moves towards the stacked piezoelectric unit 54 under pressure, the metal spring plate undergoes lateral bending deformation. When the eccentric wheel 43 separates from the stacked piezoelectric unit 54, the metal spring plate drives the moving joint 51 to reset under the action of elastic force.

[0043] The sliding displacement structure includes a groove and a slider; The slide is located on the bottom surface of the housing, the lower end of the slider is located in the slide, the upper end of the slider is fixedly connected to the actuating section 51, and the end of the actuating section 51 is provided with a pressure plate. The end face of the pressure plate is provided with elastic insulating rubber. When the pressure plate applies pressure to the stacked piezoelectric unit 54, the insulating rubber deforms, which can reset the actuating section 51 and make the pressure between the pressure plate and the stacked piezoelectric unit 54 disappear. At this time, the pressure plate and the stacked piezoelectric unit 54 are in contact or a small gap is generated.

[0044] In some embodiments, the housing is a rectangular box structure, and multiple stacked piezoelectric units 54 and integrated piezoelectric capacitors 55 are connected in series in the housing. A stacked piezoelectric unit 54 is provided on both sides of the corner of the housing. The force directions of the two stacked piezoelectric units 54 are perpendicular to each other, and the two stacked piezoelectric units 54 are connected to the actuator 51.

[0045] See Figure 4 The transmission joint includes a main actuator 58 and a secondary actuator 57. One end of each of the two secondary actuators 57 is connected to a pressure plate, and the other end of each secondary actuator 57 is connected to a pressure block. The two secondary actuators 57 are arranged perpendicular to each other. The main actuator 58 is located on the centerline between the included angles of the two secondary actuators 57. One end of the main actuator 58 is connected to the end of each of the two pressure plates that are close to each other via an adapter arm. The other end of the main actuator 58 is connected to the middle of the pressure block. The bottom of the main actuator 58 is connected to the housing via a spring arm. The lower end of the secondary actuator 57 is connected to the bottom of the housing via a sliding displacement structure. When the eccentric wheel 43 applies tangential pressure to the pressure block, the pressure plate synchronously drives the two secondary actuators 57 to apply pressure to the two stacked piezoelectric units 54 through the main actuator 58.

[0046] In this embodiment, a stacked piezoelectric unit 54 group is respectively arranged at the four corners of the housing. Each stacked piezoelectric unit 54 group includes two stacked piezoelectric units 54 connected in series. An integrated piezoelectric capacitor 55 is connected in series between the two stacked piezoelectric unit 54 groups through a cable 56. The integrated piezoelectric capacitor 55 is used to store the electrical energy output by the stacked piezoelectric unit 54 through piezoelectric excitation under compressive stress.

[0047] See again Figure 2 The solid circle represents the eccentric wheel, and the other three dashed circles represent the trajectory of the eccentric wheel at each actuation stage.

[0048] In some embodiments, the eccentric wheel 43 is provided with a trigger block 45, which is used to apply tangential pressure to the pressure block.

[0049] See Figure 3 The trigger block 45 is a protruding structure or roller located on the side wall of the eccentric wheel 43.

[0050] By using the arc-shaped surface extrusion of the roller and the pressure block, the sliding friction between the eccentric wheel 43 and the pressure block is converted into rolling friction, which can reduce friction and friction noise. The protruding structure and the eccentric wheel 43 are detachably connected. When the protruding structure is damaged, the trigger block 45 can be replaced, avoiding the need to replace the eccentric wheel 43 and reducing maintenance costs.

[0051] In some embodiments, the transmission device 4 includes transmission rods 44 and a base plate 42. With the center of the eccentric wheel 43 as the midpoint, multiple transmission rods 44 are evenly distributed around the eccentric wheel 43. The lower end of the transmission rods 44 is inserted into the upper surface of the eccentric wheel 43. The base plate 42 is fixed to the upper end of the multiple transmission rods 44 and is in a horizontal state. The tray frame 2 is fixed on the base plate 42. Multiple screen plates 31 are located between the tray frames 2 and are stacked. The rotation of the eccentric wheel 43 causes the tray frame 2 to vibrate horizontally through the transmission device, thereby screening the aggregate in the screen plates 31.

[0052] Multiple screen discs 31 are stacked from bottom to top, and the screen openings of the multiple screen discs 31 decrease sequentially from top to bottom. Thus, the aggregate is screened layer by layer according to the different screen openings to form aggregates of different particle sizes.

[0053] In some embodiments, the pallet frame 2 includes a plurality of support rods 22 and a pressure plate 21; Multiple support rods 22 are arranged on the base plate 42 and evenly distributed around the circumference. Multiple screen plates 31 are located between the multiple support rods 22. The pressure plate 2121 is located on top of the uppermost screen plate 31. The pressure plate 21 is connected to the support rods 22 by fastening nuts 2323.

[0054] The tray 32 is located at the bottom of the lowest screen tray 31, i.e., at the bottom of the screen tray 31 with the smallest screen holes. The piezoelectric layer is located in the tray 32, and the piezoelectric sensor 41 is located at the center of the base tray 42. The tray 32 sits on the base tray 42, and the piezoelectric layer is electrically connected to the piezoelectric sensor 41. During the screening process, the aggregate screened out by the smallest screen hole falls into the tray 32. The gravity of the falling aggregate generates piezoelectric excitation on the piezoelectric layer. The piezoelectric sensor 41 acquires the waveform signal. The stress generated by the interlocking of the aggregate under the excitation generates a weak waveform signal. When the lowest screen tray 31 stops dropping aggregate, the piezoelectric excitation is interrupted, the sensor cannot capture the waveform signal, and no waveform signal is generated within the set time. The controller 11 then determines that the screening experiment is completed, and the excitation device 1 stops working.

[0055] The piezoelectric layer is integrated into the bottom of the tray 32 and is made of piezoelectric materials such as piezoelectric ceramics or flexible PVDF films. The surface is covered with electrodes and electrically connected to the piezoelectric sensor 41. The tray 32 is located below the smallest screen hole of the bottom screen tray 31 and directly receives the screened material. Its structural design ensures that the gravity of the material is evenly applied to the surface of the piezoelectric layer, while the base plate 42 fixes its position and maintains stable signal transmission with the sensor.

[0056] Based on the positive piezoelectric effect, when the aggregate falls into the tray 32, its gravity causes the piezoelectric layer to deform, and the change in the internal dipole moment generates a weak piezoelectric signal; the piezoelectric sensor 41 monitors the signal characteristics in real time, and if there is no new signal within the set time, it indicates that the screening is completed, and the controller 11 shuts down the excitation device 1.

[0057] This system enables intelligent determination of the screening endpoint, avoiding errors caused by traditional manual experience; the piezoelectric signal directly reflects the dynamics of the aggregate, improving screening accuracy and efficiency. Furthermore, this structure requires no additional energy consumption and, in conjunction with a self-powered system, enhances the equipment's energy-saving characteristics, making it suitable for automated road engineering testing scenarios.

[0058] In some embodiments, a lighting device is provided on the housing of the excitation device 1, and the lighting device is connected to the piezoelectric device 5, which supplies power to the lighting device.

[0059] The lighting device includes a support 24 and a lamp 13. The support 24 is located on the top of the housing, and a lamp post is mounted on the support 24. The lamp 13 is located on the top of the lamp post and is connected to an integrated piezoelectric capacitor 55.

[0060] In some embodiments, a plurality of infrared sensors 12 are arranged in a ring on the top of the housing of the vibration device 1. The infrared sensors 12 are connected to and powered by the piezoelectric device 5. The infrared sensors 12 emit infrared light vertically upward and are located outside the vibration range of the screen. The infrared sensors 12 are connected to the control unit.

[0061] During the screening process, when a worker's limbs pass through the infrared light sensor and enter the vibration range of the screen, the controller 11 controls the excitation device 1 to stop working, thus protecting the worker.

[0062] Infrared sensor 12 is powered by electrical energy converted from piezoelectric device 5 and emits an infrared beam vertically upwards, forming a ring-shaped monitoring area around the vibrating range of the screen. When the equipment is running, the control unit receives infrared signals from each sensor in real time. If a person or foreign object enters the monitoring area and blocks the beam, the sensor immediately transmits an interruption signal to the control unit, triggering the safety protection mechanism. This design utilizes the linear propagation characteristics of infrared light, combined with a multi-sensor ring layout, to achieve comprehensive monitoring without blind spots, ensuring physical isolation between the vibrating working area and the operator. This significantly improves the equipment's safety performance: firstly, the active protection can quickly cut off power and stop the machine approximately 0.1-0.3 seconds before personnel accidentally enter the dangerous area, avoiding mechanical injury; secondly, the ring layout covers the entire circumference of the screen, eliminating monitoring blind spots; thirdly, the piezoelectric self-powered system reduces additional wiring and enhances system reliability; and fourthly, the non-contact detection does not interfere with the screening process and has strong resistance to dust interference, making it suitable for harsh working conditions.

[0063] In some embodiments, the control unit is disposed on the end face of the housing, and the control unit includes a controller 11 and a display.

[0064] The working principle of an energy-saving vibrating aggregate screening device of this application will be described in detail below.

[0065] According to the requirements of the screening experiment, multiple screen plates 31 are stacked on the top of the tray 32. The diameter of the screen holes of the screen plates 31 decreases from top to bottom. The aggregate is poured into the uppermost screen plate 31 and sealed and fixed by the pressure plate 21.

[0066] When the power is turned on, the excitation device 1 generates a stable frequency of rotation, causing the screen plate 31 to vibrate horizontally. Under the action of vibration, the aggregate is screened, and aggregates of different sizes fall into the corresponding mesh layers of screen plate 31, thus realizing the screening of the aggregate.

[0067] During the screening process, the aggregate screened out by the bottom screen plate 31 falls into the tray 32 under the action of gravity. At the same time, the aggregate under the action of gravity generates piezoelectric excitation on the piezoelectric layer, which generates a corresponding piezoelectric waveform signal. This signal is synchronously captured by the piezoelectric sensor 41 and transmitted to the screener display. After a certain screening time, the bottom screen plate 31 stops screening aggregate. At this time, the piezoelectric excitation of the piezoelectric layer is interrupted, and the sensor cannot capture the waveform signal. When the piezoelectric excitation interruption time exceeds the set time, the controller 11 outputs a stop command, and the screening is completed.

[0068] During the screening process, the eccentric wheel 43 rotates continuously. During this rotation, the eccentric wheel 43 periodically triggers each piezoelectric device 5 in sequence. The rotational force generated by the eccentric wheel 43 is converted into a horizontal tangential force by the actuator 51 and applied to the stacked piezoelectric unit 54. Under stress, the stacked piezoelectric unit 54 realizes piezoelectric excitation conversion and outputs electrical energy stored in the integrated piezoelectric capacitor 55. The integrated piezoelectric capacitor 55 functions to power the lighting lamp 13 and the infrared sensor 12. At the same time, in the power failure state, the integrated piezoelectric capacitor 55 provides auxiliary power to the drive motor to enable the vibration device 1 to work.

[0069] Infrared sensors 12 are installed at the four corners of the end face of the excitation device 1 around the excitation tray 32. The infrared signals emitted vertically upwards form a spatial enclosure for the excitation operation. When personnel or foreign objects accidentally touch or approach the vibrating conductive module, the infrared rays are blocked, the infrared sensors 12 identify the blockage and initiate an emergency power cut-off, and the machine stops; when the infrared signal returns to normal, the machine restarts. Example 1

[0070] An energy-saving vibrating aggregate screening device includes: The excitation device 1 adopts a rectangular shell design, and an eccentric wheel 43 driven by a drive motor is installed inside. A detachable roller trigger block 45 is installed on the side wall of the eccentric wheel 43.

[0071] A set of piezoelectric devices 5 is installed at each of the four corners of the housing. Each set of piezoelectric devices 5 includes two vertically arranged stacked piezoelectric units 54, an integrated piezoelectric capacitor 55, and an actuating joint 51 with an arc-shaped pressure block. The arc-shaped surface is covered with a 3mm thick fluororubber flexible pad.

[0072] The tray frame 2 includes 4 stainless steel support rods 22 distributed in a 90° circle. 5 standard sieve trays 31 are stacked in the tray frame 2 from top to bottom in descending order of aperture size. The bottom tray 32 has a built-in PVDF piezoelectric film layer with a thickness of 0.2 mm. The piezoelectric sensor 41 is embedded in the center of the aluminum alloy base plate 42.

[0073] Pour the material to be screened into the top screen plate 31 with a diameter of 16mm, tighten the 304 stainless steel fastening nut 23 on the top pressure plate 21, and set the controller 11 to set the screening termination judgment time to 30 seconds without signal.

[0074] The drive motor rotates the eccentric wheel 43 at a speed of 2800 rpm. The trigger block 45 triggers the stacked piezoelectric unit 54, generating 15 mJ of electricity per cycle. The horizontal amplitude of the screen plate 31 is controlled at 2 ± 0.1 mm. The material falling from the bottom screen plate 31 with a hole diameter of 0.6 mm triggers the piezoelectric layer to generate a 10-100 mV signal.

[0075] Four infrared sensors 1212 form a monitoring plane 50mm from the edge of the screen 31. When a foreign object enters the monitoring area, the controller 11 cuts off the power within 0.2 seconds. In the power outage state, the energy storage capacitor can maintain the operation of the entire device.

[0076] This application discloses a technical solution for an energy-saving vibrating aggregate screening device. Firstly, its intelligent control system monitors the aggregate screening status in real time through a piezoelectric layer and piezoelectric sensor 41, accurately determining the screening endpoint and automatically stopping the machine. This completely solves the problems of insufficient screening or time redundancy caused by reliance on manual experience in traditional methods, significantly improving the accuracy and consistency of screening tests. Secondly, the device innovatively adopts an energy recovery design, converting the mechanical energy of the eccentric wheel 43's rotation into electrical energy through the piezoelectric device 5. This not only achieves self-powered operation, reducing external energy consumption, but also provides power for auxiliary equipment such as lighting and sensors, significantly improving energy utilization efficiency. Furthermore, the device employs a highly integrated solution, organically combining the vibration device 1, the piezoelectric power generation module, and the screening tray 32, resulting in a compact structure and convenient maintenance. Finally, the device is equipped with an infrared sensor 12 and an emergency power-off function, which can promptly detect personnel approach and automatically stop the machine, effectively ensuring operational safety. In addition, the combination of flexible connectors and the intelligent control system reduces mechanical wear, extends equipment lifespan, and avoids excessive aggregate crushing, ensuring the accuracy of test data. This device also boasts strong environmental adaptability; its self-powered system can maintain normal operation even in environments with unstable power supply or in the field, greatly expanding its application scenarios. Through mechatronics design, the device achieves comprehensive optimization in screening efficiency, energy utilization, operational safety, and equipment reliability, providing an efficient, precise, and environmentally friendly solution for aggregate screening in road engineering, with broad market application prospects and promotional value.

[0077] The above content is only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed in this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. An energy-saving vibrating aggregate screening device, characterized in that, Includes excitation device, piezoelectric device and piezoelectric tray; The excitation device includes a housing and an eccentric wheel disposed inside it. Multiple piezoelectric devices are disposed in the housing and located on the rotation trajectory of the eccentric wheel. During rotation, the eccentric wheel can apply compressive stress to the piezoelectric devices, and the piezoelectric devices can convert piezoelectric excitation into output electrical energy. The piezoelectric tray includes a tray frame, a sieve tray, a tray, a piezoelectric layer, and a piezoelectric sensor; The tray frame is connected to the eccentric wheel through a transmission device. Multiple screens are stacked on the tray frame from top to bottom. The tray is located at the bottom of the bottommost screen. The piezoelectric layer is located in the tray. The piezoelectric layer generates a piezoelectric excitation signal under the gravity of the aggregate screened off the bottommost screen. The piezoelectric layer is connected to the piezoelectric sensor. The excitation device and the piezoelectric sensor are respectively connected to the control unit. The control unit determines the screening completion time based on the piezoelectric excitation signal and controls the operation of the excitation device.

2. The energy-saving vibrating aggregate screening device according to claim 1, characterized in that, The piezoelectric device includes a stacked piezoelectric unit, an actuator, and a pressure block; The stacked piezoelectric unit is fixed on the side wall of the housing. The bottom of the actuating section is connected to the housing through a displacement structure. One end of the actuating section is used to apply pressure to the stacked piezoelectric unit, and the other end of the actuating section is connected to the pressure block, which is located on the rotation trajectory of the eccentric wheel.

3. The energy-saving vibrating aggregate screening device according to claim 2, characterized in that, An insulating actuation pad is provided on the side of the pressure plate near the stacked piezoelectric unit, and the side of the pressure block near the eccentric wheel is an arc-shaped surface, the curvature of which is less than the curvature of the circular trajectory of the eccentric wheel.

4. The energy-saving vibrating aggregate screening device according to claim 2, characterized in that, The displacement structure is either an elastic displacement structure or a sliding displacement structure.

5. The energy-saving vibrating aggregate screening device according to claim 2, characterized in that, Stacked piezoelectric units are respectively provided on both sides of the corner of the housing; The transmission joint includes a main actuator joint and a secondary actuator joint. One end of the two secondary actuator joints is connected to two pressure plates respectively, and the other end of the two secondary actuator joints is connected to a pressure block. The main actuator joint is located on the centerline between the included angles of the two secondary actuator joints. One end of the main actuator joint is connected to the end of the two pressure plates that are close to each other through an adapter arm, and the other end of the main actuator joint is connected to the middle of the pressure block.

6. The energy-saving vibrating aggregate screening device according to claim 1, characterized in that, The eccentric wheel is provided with a trigger block, which is used to apply tangential pressure to the pressure block; The trigger block is a protruding structure or a roller located on the side wall of the eccentric wheel.

7. The energy-saving vibrating aggregate screening device according to claim 1, characterized in that, The transmission device includes transmission rods and a base plate. With the center of the eccentric wheel as the midpoint, multiple transmission rods are evenly distributed around the eccentric wheel. The base plate is fixed to the upper end of the multiple transmission rods and is in a horizontal state. The pallet frame is fixed on the base plate.

8. The energy-saving vibrating aggregate screening device according to claim 7, characterized in that, The piezoelectric layer is disposed in the tray, the piezoelectric sensor is fixed on the base plate, and the piezoelectric layer is pressed onto the piezoelectric sensor and electrically conductive.

9. The energy-saving vibrating aggregate screening device according to claim 1, characterized in that, The mesh size of the plurality of sieve discs decreases sequentially from top to bottom.

10. The energy-saving vibrating aggregate screening device according to claim 1, characterized in that, The top of the housing of the excitation device is provided with multiple infrared sensors arranged in a ring. The infrared sensors are connected to the piezoelectric device. The infrared sensors emit infrared light vertically upward and are located outside the vibration range of the screen. The infrared sensors are connected to the control unit.

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