Spiral fertilization trolley and control method thereof

Abstract

The invention provides a spiral fertilization trolley and a control method thereof. The spiral fertilization trolley comprises a fertilization mechanism, the fertilizing mechanism comprises a fertilizer box, a stepping motor, a spiral main shell, a spiral, a driving shaft, a piezoelectric ceramic piece and a blanking pipe; a fertilizer filling opening is formed in the upper portion of one side of the spiral main shell, the fertilizer box is installed over the fertilizer filling opening, and the stepping motor is installed on one side of the spiral main shell. A spiral is rotationally arranged in the spiral main shell, a driving shaft is arranged in the spiral, one end of the driving shaft is connected with an output shaft of the stepping motor, the other end of the driving shaft is rotationally installed in a bearing seat, and the bearing seat is installed on the other side of the spiral main shell; a fertilizer discharge port is arranged below the other side of the spiral main shell, and a blanking pipe is arranged below the fertilizer discharge port; and a plurality of groups of stacked piezoelectric ceramic pieces are sleeved outside the blanking pipe. According to the invention, the inverse piezoelectric effect of the piezoelectric ceramic piece excites the blanking pipe to generate traveling wave motion, so that the adhesion and blockage risks of the fertilizer in the blanking pipe are effectively reduced, the continuous and uniform fertilizer discharge is ensured, and the efficiency of the fertilization operation is improved.

Description

Technical Field

[0001] The invention belongs to the field of agricultural fertilization, and particularly relates to a spiral fertilizing trolley and a control method thereof. Background Art

[0002] Fertilizer is a key element in ensuring increased crop yields. While existing spiral fertilizer spreaders can improve uniformity by forced fertilizer distribution, they still have the following limitations:

[0003] 1. Fertilizer is easily clogged in the drop pipe, affecting continuous operation, and cannot be discharged continuously and evenly, affecting the efficiency of fertilization operation;

[0004] 2. The adjustment of fertilizer discharge volume depends on mechanical structure and manual intervention, and its dynamic response capability is weak. Summary of the Invention

[0005] In response to the above technical problems, the present invention provides a spiral fertilizer trolley and a control method thereof, which stimulates the drop tube to produce traveling wave motion through the inverse piezoelectric effect of the piezoelectric ceramic sheet, effectively reducing the risk of fertilizer adhesion and blockage in the drop tube, which is conducive to ensuring continuous and uniform fertilizer discharge, thereby greatly improving the efficiency of the fertilization operation.

[0006] Note that the inclusion of these objectives does not preclude the existence of other objectives. One embodiment of the present invention does not necessarily achieve all of the above objectives. Objectives other than the above objectives may be extracted from the description of the specification, drawings, and claims.

[0007] The present invention achieves the above technical objectives through the following technical means.

[0008] A spiral fertilizer trolley includes a fertilizer mechanism; the fertilizer mechanism includes a fertilizer box, a stepping motor, a spiral main housing, a spiral, a drive shaft, a piezoelectric ceramic sheet and a drop pipe;

[0009] A fertilizer filling port is provided above one side of the spiral main housing, the fertilizer box is installed just above the fertilizer filling port, and the stepping motor is installed on one side of the spiral main housing;

[0010] A spiral is rotatably provided inside the spiral main shell, and a drive shaft is provided inside the spiral. One end of the drive shaft is connected to the output shaft of the stepper motor, and the other end is rotatably installed in the bearing seat, and the bearing seat is installed on the other side of the spiral main shell; a fertilizer discharge port is provided below the other side of the spiral main shell, and a drop pipe is provided below the fertilizer discharge port; the outer sleeve of the drop pipe is provided with several groups of stacked piezoelectric ceramic sheets.

[0011] In the above solution, a fertilizer discharge baffle is provided at the fertilizer filling port of the fertilizer box and the spiral main shell.

[0012] In the above solution, each group of piezoelectric ceramic sheets includes two piezoelectric ceramics, and the piezoelectric ceramics are arranged in a stacked manner.

[0013] Furthermore, the number of the piezoelectric ceramic sheets is two groups, which are symmetrically distributed and respectively arranged at both ends of the central shaft sleeve. The piezoelectric ceramic sheets and the central shaft sleeve are sleeved in the middle of the blanking tube, and the four piezoelectric ceramics are arranged in a stacked manner.

[0014] Furthermore, the piezoelectric ceramic sheet and the central shaft sleeve are bonded together by epoxy resin adhesive and are arranged in the middle of the blanking tube.

[0015] The above scheme also includes a frame and a top plate; running wheels are provided below the frame, a top plate is provided above the frame, and the spiral main shell is installed on the top plate.

[0016] In the above solution, the spiral main shell is installed on the top plate through a support block.

[0017] The above solution also includes a battery pack; the battery pack is arranged in the interlayer between the frame and the top plate, and the battery pack is connected to the stepper motor and the piezoelectric ceramic sheet.

[0018] The above solution also includes a Raspberry Pi controller and a speed sensor; the speed sensor is used to detect the speed of the drive shaft and transmit it to the Raspberry Pi controller; the Raspberry Pi controller is connected to the battery pack and the piezoelectric ceramic piece.

[0019] A control method according to the spiral fertilizer application vehicle comprises the following steps:

[0020] Adjust the fertilizer discharge baffle to a preset position, adjust the stepper motor speed to a preset speed, and drive the drive shaft to rotate through the stepper motor, which drives the spiral to rotate. Under the action of gravity, the fertilizer particles are discharged through the fertilizer filling port of the spiral main body and contact the spiral. Under the action of the spiral rotation, the fertilizer particles move from one end of the spiral main body to the other end of the spiral main body along the spiral shaft diameter direction. Then, the fertilizer particles are discharged from the fertilizer discharge port of the spiral main body and slide into the drop pipe through the fertilizer discharge port.

[0021] The speed sensor detects the speed of the drive shaft and transmits it to the Raspberry Pi controller; the Raspberry Pi controller compares the detected speed with a preset value. When the detected speed is less than the preset value, the Raspberry Pi controller controls the battery pack to supply a sinusoidal AC voltage with a voltage time phase difference of π / 2 to the two groups of stacked piezoelectric ceramics on the piezoelectric ceramic sheet. The spatial phase difference between the two groups of piezoelectric ceramics is also π / 2, which stimulates the inner wall of the drop tube to generate a positive traveling wave. When the traveling wave propagates on the inner wall of the drop tube, it contacts and interacts with the fertilizer in the tube. Due to the vibration characteristics of the traveling wave, it will exert a periodic force on the fertilizer. After the accumulation of multiple vibration cycles, the fertilizer gradually moves downward along the direction of propagation of the positive traveling wave and is discharged from the drop tube.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention installs a piezoelectric ceramic sheet on the outer surface of the drop tube. The inverse piezoelectric effect of the piezoelectric ceramic sheet generates traveling wave motion on the inner wall of the drop tube, effectively reducing the risk of fertilizer adhesion and clogging in the drop tube, ensuring continuous and uniform fertilizer discharge, and thus significantly improving the efficiency of the fertilization operation.

[0024] 2. When the Raspberry Pi controller of the present invention controls the battery pack to connect a sinusoidal AC voltage with a voltage time phase difference of π / 2 to the two groups of stacked piezoelectric ceramics on the piezoelectric ceramic sheet, the spatial phase difference between the two groups of piezoelectric ceramics is also π / 2, which excites the inner wall of the drop tube to generate a positive traveling wave. When the traveling wave propagates on the inner wall of the drop tube, it contacts and interacts with the fertilizer in the tube. Due to the vibration characteristics of the traveling wave, it exerts a periodic force on the fertilizer. After the accumulation of multiple vibration cycles, the fertilizer gradually moves downward along the direction of the traveling wave propagation, pushing the fertilizer to move in the direction of the traveling wave propagation. In this way, the blockage is broken and the fertilizer can be discharged smoothly.

[0025] 3. The present invention controls the speed of the spiral by adjusting the speed of the stepping motor, thereby controlling the discharge amount of fertilizer, realizing the function of variable fertilizer discharge; and a fertilizer discharge baffle is provided at the fertilizer filling port. Before the trolley works, the range of the fertilizer discharge baffle is adjusted according to the fertilizer characteristics of different fertilizer-requiring crops, and the opening of the fertilizer discharge baffle is manually adjusted. The fertilizer discharge baffle can buffer the speed of the fertilizer falling due to gravity, so that the fertilizer entering the spiral is more evenly distributed, reducing the problem of fluctuating fertilizer discharge amount due to feed fluctuations.

[0026] 4. The present invention has a compact structure and a modular design that takes into account both functionality and mobility, making it suitable for operations in small farmlands with complex terrain.

[0027] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a spiral fertilizer trolley according to one embodiment of the present invention. Figure 1 .

[0029] Figure 2 This is a schematic diagram of the structure of a spiral fertilizer trolley according to one embodiment of the present invention. Figure 2 .

[0030] Figure 3 The figure is a schematic diagram of the upper fertilizing structure of the spiral fertilizing trolley according to one embodiment of the present invention.

[0031] Figure 4 The figure is a schematic diagram of the lower frame structure of a spiral fertilizer spreading trolley according to one embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the middle shaft sleeve structure according to one embodiment of the present invention, wherein: Figure 5 (a) is the main view of the middle shaft sleeve, Figure 5 (b) is the side view of the middle shaft sleeve. Figure 5 (c) is a three-dimensional diagram of the middle shaft sleeve.

[0033] Figure 6 Schematic diagram of the structure of a piezoelectric ceramic sheet according to an embodiment of the present invention, wherein: Figure 6 (a) is the front view of the piezoelectric ceramic sheet. Figure 6 (b) is the side view of the piezoelectric ceramic sheet. Figure 6 (c) is a three-dimensional image of the piezoelectric ceramic sheet.

[0034] Figure 7 Schematic diagram of the blanking tube structure according to one embodiment of the present invention.

[0035] Figure 8 Schematic diagram of the traveling wave motion process of the blanking tube according to one embodiment of the present invention.

[0036] Figure 9 Schematic diagram of the motion of the surface quality nodes of the blanking tube according to one embodiment of the present invention.

[0037] In the figure, 1. fertilizer discharge baffle, 2. fertilizer box, 3. stepper motor, 4. spiral main shell, 5. spiral, 6. drive shaft, 7. piezoelectric ceramic sheet, 8. drop tube, 9. bearing seat, 10. middle shaft sleeve, 11. frame, 12. top plate, 13. Raspberry Pi controller, 14. battery pack. DETAILED DESCRIPTION

[0038] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0040] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] Figure 1-7 The figure shows a preferred embodiment of the spiral fertilizer trolley of the present invention, which includes a fertilizer mechanism; the fertilizer mechanism includes a fertilizer box 2, a stepper motor 3, a spiral main housing 4, a spiral 5, a drive shaft 6, a piezoelectric ceramic sheet 7 and a drop pipe 8;

[0042] A fertilizer filling port is provided above one side of the spiral main housing 4, the fertilizer box 2 is installed just above the fertilizer filling port, and the stepping motor 3 is installed on one side of the spiral main housing 4 by bolt connection;

[0043] A spiral 5 is rotatably provided inside the spiral main shell 4, and a drive shaft 6 is provided inside the spiral 5. One end of the drive shaft 6 is connected to the output shaft of the stepper motor 3, and the other end is rotatably installed in the bearing seat 9, and the bearing seat 9 is installed on the other side of the spiral main shell 4; a fertilizer discharge port is provided below the other side of the spiral main shell 4, and a drop pipe 8 is provided below the fertilizer discharge port; the drop pipe 8 is provided with several groups of stacked piezoelectric ceramic sheets 7 on the outer sleeve.

[0044] A fertilizer discharge baffle 1 is provided at the fertilizer filling port between the fertilizer box 2 and the main spiral housing 4. Before the trolley is in operation, the range of the fertilizer discharge baffle 1 is adjusted according to the fertilizer characteristics of different fertilizer-requiring crops, and the opening of the fertilizer discharge baffle 1 is manually adjusted. The fertilizer discharge baffle 1 can buffer the speed of the fertilizer falling due to gravity, making the fertilizer entering the spiral 5 more evenly distributed and reducing the problem of fluctuating fertilizer discharge caused by feed fluctuations.

[0045] Each group of piezoelectric ceramic sheets 7 includes two piezoelectric ceramics, and the piezoelectric ceramics are arranged in a stacked manner.

[0046] Preferably, the number of the piezoelectric ceramic sheets 7 is two groups, and the two groups of piezoelectric ceramic sheets 7 are symmetrically distributed and respectively arranged at both ends of the central shaft sleeve 10. The piezoelectric ceramic sheets 7 and the central shaft sleeve 10 are sleeved in the middle position of the blanking tube 8, and the four piezoelectric ceramics are arranged in a stacked manner.

[0047] The piezoelectric ceramic piece 7 and the middle shaft sleeve 10 are bonded together by epoxy resin glue and sleeved in the middle position of the blanking tube 8.

[0048] The spiral fertilizer applying trolley further comprises a vehicle frame 11 and a top plate 12 ; running wheels are provided below the vehicle frame 11 , a top plate 12 is provided above the vehicle frame 11 , and the spiral main housing 4 is mounted on the top plate 12 .

[0049] Preferably, the spiral main housing 4 is mounted on the top plate 12 via a support block.

[0050] like Figure 1 、 2 As shown in Figure 4, the spiral fertilizer trolley also includes a frame 11 and a top plate 12; the frame 11 is provided with running wheels below, the frame 11 is provided with a top plate 12 above, and the spiral main body 4 is mounted on the top plate 12 through a support block. The movement of the frame 11 allows the fertilizer mechanism to move to the planting area where fertilizer is needed.

[0051] like Figure 1 、 2 As shown, the spiral fertilizer spreading trolley further includes a battery pack 14 ; the battery pack 14 is disposed at the center of the sandwich between the frame 11 and the top plate 12 to balance the counterweight, and the battery pack 14 is connected to the stepper motor 3 and the piezoelectric ceramic piece 7 .

[0052] like Figure 4 As shown, the spiral fertilizer spreading vehicle also includes a Raspberry Pi controller 13 and a speed sensor; the speed sensor is used to detect the speed of the drive shaft 6 and transmit it to the Raspberry Pi controller 13; the Raspberry Pi controller 13 is connected to the battery pack 14 and the piezoelectric ceramic plate 7. Preferably, the Raspberry Pi controller 13 is installed in the middle of the top plate 12 between the two support blocks to facilitate wiring with other devices.

[0053] The fertilizer particles are transported to the fertilizer box 2, the fertilizer discharge baffle 1 is adjusted to a specific appropriate position, the speed of the stepper motor 3 is adjusted to an appropriate speed, the stepper motor 3 drives the drive shaft 6 to rotate, and the drive shaft 6 drives the screw 5 to rotate. The fertilizer particles are discharged through the fertilizer filling port of the spiral main shell 4 under the action of gravity and contact the spiral 5. Under the action of the rotation of the spiral 5, the fertilizer particles move from the left end of the spiral main shell 4 to the right end of the spiral main shell 4 along the axial direction of the spiral 5, and then the fertilizer particles are discharged from the fertilizer discharge port on the right side of the spiral main shell 4, and then slide into the drop pipe 8 through the fertilizer discharge port. Finally, the fertilizer particles are driven into the soil to complete the fertilization.

[0054] When the speed of the screw 5 increases, the uniformity of the fertilizer discharge flow rate also increases. However, the speed of the screw 5 is greater than the limit speed n max When the fertilizer discharge screw 5 in the cavity mainly stirs the fertilizer, the axial displacement of the fertilizer is small, and the fertilizer cannot be discharged normally. The actual speed of the screw 5 must be less than or equal to the limit speed n max .

[0055] Limiting speed n max The calculation formula is:

[0056]

[0057] Where: n max is the maximum speed of the fertilizer screw, r / min;

[0058] C is the comprehensive characteristic coefficient of the material;

[0059] D is the outer diameter of the fertilizer discharge spiral, mm.

[0060] The calculation formula of the fertilizer discharge amount of the spiral 5 is as follows:

[0061]

[0062] Q = qrt

[0063] Where: q represents the amount of fertilizer discharged per cycle, g;

[0064] L p Indicates the average length of the screw thread, mm;

[0065]

[0066] ρ represents fertilizer density, g / mm 3 ;

[0067] Indicates the filling factor of the fertilizer spiral, %;

[0068] Q represents the amount of fertilizer discharged, g;

[0069] r represents the speed of the driving motor, r / min;

[0070] t represents time, s;

[0071] d is the inner diameter of the spiral, mm;

[0072] S is the thread pitch, mm;

[0073] h is the thread depth, mm;

[0074] b is the average thickness of the thread, mm.

[0075] Combine Figure 5-7 As shown, in a specific embodiment of the present invention, the following structure and dimensions are selected through modal analysis: the middle shaft sleeve 10 is made of copper alloy, with a thickness of 14 mm, an inner diameter of 12 mm, and an outer diameter of 35 mm; Figure 5 As shown in (a)-(c), the piezoelectric ceramic is lead zirconate titanate PZT-4, with a thickness of 5 mm, an inner diameter of 14.7 mm, and an outer diameter of 35 mm; Figure 6 As shown in (a)-(c), the blanking tube 8 is made of copper alloy, with a total length of 122 mm, an inner diameter of 8 mm, and an outer diameter of 10 mm. The spiral 5 has an inner diameter of 12 mm, an outer diameter of 80 mm, a pitch of 40 mm, and an average thickness of the thread of 2 mm. Figure 7 shown.

[0076] A control method according to the spiral fertilizer application vehicle comprises the following steps:

[0077] Adjust the fertilizer discharge baffle 1 to a preset position, adjust the speed of the stepper motor 3 to a preset speed, and drive the drive shaft 6 to rotate through the stepper motor 3, which drives the screw 5 to rotate. Under the action of gravity, the fertilizer particles are discharged through the fertilizer filling port of the screw main housing 4 and contact the screw 5. Under the action of the rotation of the screw 5, the fertilizer particles move from one end of the screw main housing 4 to the other end of the screw main housing 4 along the axial direction of the screw 5. Then, the fertilizer particles are discharged from the fertilizer discharge port of the screw main housing 4 and slide into the drop pipe 8 through the fertilizer discharge port.

[0078] The speed sensor detects the speed of the drive shaft 6 and transmits it to the Raspberry Pi controller 13; the Raspberry Pi controller 13 compares the detected speed with a preset value. When the detected speed is less than the preset value, the Raspberry Pi controller 13 controls the battery pack 14 to apply a sinusoidal AC voltage with a time phase difference of π / 2 to the two groups of stacked piezoelectric ceramic plates 12 on the piezoelectric ceramic plate 7. The voltage and spatial phase difference between the two groups of piezoelectric ceramic plates is also π / 2, which excites the inner wall of the drop tube 8 to generate a positive traveling wave. When the traveling wave propagates on the inner wall of the drop tube 8, it contacts and interacts with the fertilizer in the tube. Due to the vibration characteristics of the traveling wave, it exerts a periodic force on the fertilizer. When the traveling wave propagates forward, in each vibration cycle, the traveling wave will first push the fertilizer forward a distance. Then, in the return phase of the vibration, due to factors such as the friction between the fertilizer and the inner wall of the drop tube 8 and the internal friction between the fertilizers, the fertilizer will not completely return to its original position. After the accumulation of multiple vibration cycles, the fertilizer will gradually move downward along the direction of the traveling wave propagation and be discharged from the drop tube 8.

[0079] like Figure 8 As shown, when the sinusoidal AC voltage signal is turned on, the traveling wave motion of the drop tube 8 is as shown in the schematic diagram, T is a complete motion cycle, t represents the time of change, when t = 0, the drop tube 8 does not deform, when t = 1 / 4T, the drop tube 8 deforms and the vibration reaches the amplitude, when t = 1 / 2T, the drop tube 8 returns to the initial position, when t = 3 / 4T, the drop tube 8 deforms, and the vibration reaches the amplitude again. During the entire motion cycle, the reciprocating traveling wave motion of the drop tube 8 pushes the fertilizer to move along the direction of the traveling wave propagation, thus breaking the blockage state, being able to discharge the fertilizer smoothly, reducing the risk of blockage, and being discharged evenly and stably from the drop tube 8 into the soil, effectively reducing the risk of fertilizer adhesion and blockage in the drop tube 8, which is conducive to continuous and uniform fertilizer discharge and improves the efficiency of fertilization operations.

[0080] Furthermore, according to the principle of standing wave superposition, the superposition of two standing waves with the same frequency and amplitude, and a phase difference of π / 2 in both time and space, can form a traveling wave. To more clearly and intuitively understand the motion of particles on the surface of the blanking tube 8, the blanking tube 8 was arranged horizontally and the motion of particles on the surface of the blanking tube 8 was analyzed. Figure 9 The midpoint line represents the undeformed blanking tube 8, the solid line represents the deformed blanking tube 8 after the traveling wave is generated, the x coordinate coincides with the neutral axis of the blanking tube 8 before deformation, and the dotted line represents the neutral axis of the blanking tube 8 after deformation.

[0081] The vibrations of the two groups of piezoelectric ceramics 7 are excited independently of each other. The excitation voltage μ is applied to the two groups of piezoelectric ceramics 7. z and μ w The excitation frequency of the two groups of piezoelectric ceramics 7 is the same as ω, the voltage amplitude is Uz and Uw, and the voltage time phase difference is is π / 2

[0082]

[0083] Under the above excitation, the particles on the surface of the blanking tube 8 will produce elliptical motion. (Here, it is assumed that the propagation time of the standing waves from the two groups of piezoelectric ceramics 7 to the surfaces of the two ends of the blanking tube 8 is the same, that is, it is assumed that the time difference of the elastic wave due to the different paths can be ignored.) At this time, U represents the z-axis displacement of the mass node on the surface of the blanking tube 8, and W represents the x-axis displacement of the mass node. The motion of the particles on the surface of the blanking tube 8 can be expressed as:

[0084]

[0085] Where ω represents the resonant frequency, U0 and W0 represent the two-phase standing wave amplitudes, and U0 = W0. is the phase difference between the two-phase excitation space.

[0086] Eliminating time t from this, we have:

[0087]

[0088] When the phase difference between the two phase excitations When is π / 2, the traveling wave is a forward traveling wave, and the motion trajectory equation of its particle can be expressed as:

[0089]

[0090] The direction of elliptical motion is Figure 9 As shown, the above formula proves that under the action of traveling waves, the particles on the surface of the drop tube 8 form a continuous alternating elliptical motion. At this time, the elliptical motion direction of the particles on the surface of the drop tube 8 is counterclockwise, and the driving force direction on the fertilizer is along the positive direction of the x-axis.

[0091] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0092] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A spiral fertilizer trolley, characterized in that: The invention comprises a fertilizing mechanism; the fertilizing mechanism comprises a fertilizer box (2), a stepping motor (3), a spiral main housing (4), a spiral (5), a driving shaft (6), a piezoelectric ceramic sheet (7) and a drop pipe (8); A fertilizer filling port is provided above one side of the spiral main housing (4), the fertilizer box (2) is installed directly above the fertilizer filling port, and the stepping motor (3) is installed on one side of the spiral main housing (4); A spiral (5) is rotatably provided inside the spiral main shell (4), and a drive shaft (6) is provided inside the spiral (5). One end of the drive shaft (6) is connected to the output shaft of the stepper motor (3), and the other end is rotatably installed in the bearing seat (9), and the bearing seat (9) is installed on the other side of the spiral main shell (4); a fertilizer discharge port is provided below the other side of the spiral main shell (4), and a drop pipe (8) is provided below the fertilizer discharge port; the drop pipe (8) is provided with a plurality of stacked groups of piezoelectric ceramic sheets (7) on its outer shell.

2. The spiral fertilizer applying trolley according to claim 1, characterized in that: A fertilizer discharge baffle (1) is provided at the fertilizer filling port of the fertilizer box (2) and the spiral main shell (4).

3. The spiral fertilizer applying trolley according to claim 1, characterized in that: Each group of piezoelectric ceramic sheets (7) comprises two piezoelectric ceramics, and the piezoelectric ceramics are arranged in a stacked manner.

4. The spiral fertilizer applying trolley according to claim 3, characterized in that: The piezoelectric ceramic sheets (7) are in two groups, and the two groups of piezoelectric ceramic sheets (7) are symmetrically distributed and respectively arranged at both ends of the central shaft sleeve (10). The piezoelectric ceramic sheets (7) and the central shaft sleeve (10) are sleeved in the middle position of the blanking tube (8), and the four piezoelectric ceramics are arranged in a stacked manner.

5. The spiral fertilizer applying trolley according to claim 4, characterized in that: The piezoelectric ceramic piece (7) and the central shaft sleeve (10) are bonded together by epoxy resin adhesive and sleeved in the middle of the blanking tube (8).

6. The spiral fertilizer applying trolley according to claim 1, characterized in that: It also includes a frame (11) and a top plate (12); Travel wheels are provided below the vehicle frame (11), a top plate (12) is provided above the vehicle frame (11), and the spiral main housing (4) is mounted on the top plate (12).

7. The spiral fertilizer applying trolley according to claim 6, characterized in that: The spiral main housing (4) is mounted on the top plate (12) via a support block.

8. The spiral fertilizer applying trolley according to claim 1, characterized in that: The vehicle further comprises a battery pack (14); the battery pack (14) is arranged in an interlayer between the vehicle frame (11) and the top plate (12); the battery pack (14) is connected to the stepping motor (3) and the piezoelectric ceramic sheet (7).

9. The spiral fertilizer applying trolley according to claim 8, characterized in that: It also includes a Raspberry Pi controller (13) and a rotation speed sensor; the rotation speed sensor is used to detect the rotation speed of the drive shaft (6) and transmit it to the Raspberry Pi controller (13); the Raspberry Pi controller (13) is connected to the battery pack (14) and the piezoelectric ceramic piece (7).

10. A method for controlling the spiral fertilizer application vehicle according to any one of claims 1 to 9, characterized in that: The following steps are involved: The fertilizer discharge baffle (1) is adjusted to a preset position, and the speed of the stepper motor (3) is adjusted to a preset speed. The stepper motor (3) drives the drive shaft (6) to rotate, and the drive shaft (6) drives the spiral (5) to rotate. The fertilizer particles are discharged through the fertilizer filling port of the spiral main housing (4) under the action of gravity and contact the spiral (5). Under the action of the rotation of the spiral (5), the fertilizer particles move from one end of the spiral main housing (4) to the other end of the spiral main housing (4) along the axial direction of the spiral (5). Then, the fertilizer particles are discharged from the fertilizer discharge port of the spiral main housing (4) and slide into the drop pipe (8) through the fertilizer discharge port. The speed sensor detects the speed of the drive shaft (6) and transmits it to the Raspberry Pi controller (13); the Raspberry Pi controller (13) compares the detected speed with a preset value. When the detected speed is less than the preset value, the Raspberry Pi controller (13) controls the battery pack (14) to connect the two groups of stacked piezoelectric ceramics on the piezoelectric ceramic sheet (7) with a sinusoidal AC voltage with a voltage time phase difference of π / 2. The spatial phase difference between the two groups of piezoelectric ceramics is also π / 2, which excites the inner wall of the drop tube (8) to generate a positive traveling wave. When the traveling wave propagates on the inner wall of the drop tube (8), it contacts and interacts with the fertilizer in the tube. Due to the vibration characteristics of the traveling wave, a periodic force is applied to the fertilizer. After the accumulation of multiple vibration cycles, the fertilizer gradually moves downward along the propagation direction of the traveling wave and is discharged from the drop tube (8).

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