Air duct assembly and variable pesticide spraying vehicle

Abstract

The invention relates to a pesticide spraying vehicle and discloses an air cylinder assembly and a variable pesticide spraying vehicle, the air cylinder assembly comprises a limiting cylinder (1) and a step pitch adjusting cylinder (2) which are internally communicated with each other and rotationally connected, a fan and an atomizing nozzle are installed in the limiting cylinder (1), a threaded rod (201) is installed in the step pitch adjusting cylinder (2), a spiral blade (202) is connected to the threaded rod (201), and the spiral blade (202) is connected to the limiting cylinder (1). The two ends of the spiral blade (202) are in threaded connection with the threaded rod (201) and can move in the axial direction of the threaded rod (201) under the rotation effect of the step pitch adjusting barrel (2). The adjustable spiral blade (202) is arranged in the air duct, so that the spraying coverage rate and uniformity can be adjusted, and a better spraying effect can be provided.

Description

Technical Field

[0001] The invention relates to a medicine spraying vehicle, in particular to a variable-variable medicine spraying vehicle. Background Art

[0002] Grapes are easily affected by diseases and pests during the actual production process. The annual yield fluctuation caused by diseases and pests can reach more than 20%. Therefore, grape disease and pest control is very important in the grape planting process.

[0003] As my country's urbanization level gradually increases and the rural labor force decreases significantly, the demand for plant protection machinery in the prevention and control of wine grape pests and diseases is becoming more and more extensive, and the requirements for its high efficiency, high quality, water saving and pesticide saving are becoming higher and higher.

[0004] At present, air-supplied spraying technology has gradually become the mainstream. It is a spraying technology that uses high-speed airflow to secondary atomize the droplets sprayed from the nozzle to form fine and uniform droplets, and then delivers these droplets to the target crops through airflow, which can effectively improve the uniformity and efficiency of spraying. However, in actual applications, the coverage and uniformity of spraying may be affected by various factors such as wind speed and planting site, resulting in poor spraying effect in some areas. Therefore, it is necessary to provide a spraying device that can automatically adjust the coverage and uniformity of spraying. Summary of the invention

[0005] The present invention aims at the problems existing in the prior art of air supply spraying and provides an air cylinder assembly and a variable spraying vehicle.

[0006] In order to solve the above technical problems, the present invention is solved by the following technical solutions: The wind cylinder assembly includes a limit cylinder and a step adjustment cylinder which are internally interconnected and rotatably connected. A fan and an atomizing nozzle are installed in the limit cylinder, a threaded rod is installed in the step adjustment cylinder, a spiral blade is connected to the threaded rod, both ends of the spiral blade are threadedly connected to the threaded rod and the two ends can move axially along the threaded rod under the rotation of the step adjustment cylinder.

[0007] Preferably, an adjusting cylinder connecting frame is installed on the inner wall of the step adjustment cylinder, and the adjusting cylinder connecting frame includes a sleeve coaxially arranged with the threaded rod and arranged outside the threaded rod, and the sleeve is provided with a guide limit hole arranged along the axial direction of the sleeve in the length direction, and threaded connectors are provided at both ends of the spiral blade, which are threadedly connected to the threaded rod and can slide along the length direction of the guide limit hole.

[0008] Preferably, there are multiple guide limit holes and they are evenly arranged around the sleeve axis; the threaded connector includes a connecting ring slidably connected to the outer wall of the sleeve and a connecting block extending into the sleeve through the guide limit hole and threadedly connected to the threaded rod, the connecting block is fixed on the inner wall of the connecting ring and can slide along the wall of the guide limit hole in the axial direction of the sleeve.

[0009] Preferably, a connecting frame of the limiting cylinder and a motor mounting frame are arranged inside the limiting cylinder. The bottom of the threaded rod is fixed on the connecting frame of the limiting cylinder. A fan motor for driving the fan to rotate is fixed on the motor mounting frame. The fan is arranged at the end of the limiting cylinder away from the step adjustment cylinder, and the atomizing nozzle is arranged on the side wall of the limiting cylinder.

[0010] Preferably, an annular step with an L-shaped cross section is constructed on the inner wall of the limiting cylinder at the end face. The end of the step adjustment cylinder is inserted on the annular step. A limiting component is arranged inside the limiting cylinder. The limiting component includes a limiting pin component arranged on the inner wall of the limiting cylinder and a limiting spring sleeved on the limiting pin component. The limiting pin component can be abutted against the end face of the step adjustment cylinder through the step surface of the annular step under the action of the limiting spring.

[0011] Preferably, it further includes a U-shaped air duct turnover frame. The limiting cylinder can be radially turned over on the air duct turnover frame. The limiting component further includes two relatively arranged rotating connecting pieces. The rotating connecting piece includes a connecting cylinder body, a connecting column body arranged inside the connecting cylinder body and capable of moving along the axial direction of the connecting cylinder body, and a driving spring for driving the connecting column body to move away from the limiting cylinder. One end of the connecting cylinder body is fixed at the end of the air duct turnover frame, and the other end is rotatably connected with the wall of the limiting cylinder. The limiting pin component includes an upper limiting pin and a lower limiting pin which are opposite and coaxially arranged. The limiting spring is arranged between the upper limiting pin and the lower limiting pin. The upper limiting pin can be abutted against the end face of the step adjustment cylinder. The end of the connecting column body extends into the limiting cylinder, and an annular limiting groove and an unlocking long groove communicated with the annular limiting groove and arranged along the axial direction of the rotating connecting piece are arranged on the side wall of the end. The lower limiting pin can be abutted against the bottom surface of the annular limiting groove under the action of the limiting spring. The bottom surface of the unlocking long groove includes a communicating end flush with the bottom surface of the annular limiting groove and an unlocking end extending towards the end face of the end of the connecting column body. The bottom surface of the unlocking long groove is inclined downward from the communicating end to the unlocking end. The arrangement of the rotating connecting piece can realize the rotational limiting and rotational unlocking of the step adjustment cylinder.

[0012] Preferably, the limiting cylinder includes a turnover connecting cylinder connected with the air duct turnover frame and a speed adjustment cylinder rotatably connected with the turnover connecting cylinder. A plurality of circumferentially uniformly arranged electrode contacts are arranged on the end face of the turnover connecting cylinder facing the speed adjustment cylinder. An electrode contact piece is arranged on the end face of the speed adjustment cylinder facing the turnover connecting cylinder. It further includes a motor controller and a control power source electrically connected with the fan motor. Any two adjacent electrode contacts are connected in series to the control power source and the motor controller through a speed regulation circuit. The electrode contact piece can only connect two adjacent electrode contacts simultaneously under the action of the rotation of the speed adjustment cylinder.

[0013] By contacting two different electrode contacts through the electrode contact piece, a speed signal phase for controlling the motor to operate at different speeds is generated, thereby completing the control of the fan motor speed and realizing the adjustment of the fan speed, so that it can be better applied to the medicaments to be applied at different growth stages and different pest distribution densities.

[0014] Preferably, annular steps are constructed at both the upper and lower end faces of the flipping connecting cylinder, and limit pin assemblies are provided at the annular steps at both the upper and lower end faces. The limit pin assemblies at both the upper and lower end faces are symmetrically arranged relative to the rotating connecting piece and have the same matching manner with the rotating connecting piece; the limit pin assembly at the lower end face can be pressed against the end face of the speed adjustment cylinder under the action of the limit spring, and thus the rotational limit of the speed adjustment cylinder can be realized.

[0015] Preferably, the speed adjustment cylinder is inserted into the flipping connecting cylinder, and an annular groove with an L-shaped cross section is provided on the outer wall of the speed adjustment cylinder, and the electrode contact piece is arranged on the bottom surface of the annular groove.

[0016] A variable spraying vehicle, which includes the aforementioned air duct assembly.

[0017] Due to the adoption of the above technical solutions, the present invention has remarkable technical effects: By arranging adjustable spiral blades in the air duct, the present invention can adjust the spraying coverage rate and uniformity, and thus can provide a better spraying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention.

[0019] Figure 2 is Figure 1 the sectional view of

[0020] Figure 3 is Figure 2 the partial enlarged view of part A in Figure 4 is the connection schematic diagram between the spiral blade and the threaded rod of the present invention.

[0021] Figure 5 is Figure 4 the structural schematic diagram of the threaded connecting piece in

[0022] Figure 6 is Figure 1 the structural schematic diagram of the flipping connecting cylinder in

[0023] Figure 7 is Figure 1 the structural schematic diagram of the speed adjustment cylinder in

[0024] Figure 8 isFigure 1 Schematic structural diagram of the middle rotating connecting piece.

[0025] Figure 9 is Figure 8 sectional view of. Specific implementation mode

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] Embodiment 1 In this embodiment, a variable spraying vehicle is provided, which includes a vehicle body, a medicine box is provided on the vehicle body, and a plurality of air duct assemblies are also provided on the vehicle body. An atomizing nozzle is arranged in the air duct assembly, and the atomizing nozzle is respectively connected to the medicine box through a hose.

[0028] Specifically, the air duct assembly in this embodiment can adjust the spraying coverage rate and uniformity, and then can provide a better spraying effect.

[0029] As Figures 1-9 shown, the specific structure of the air duct assembly is as follows: it includes a limiting cylinder 1 and a step distance adjusting cylinder 2 that are internally connected and rotatably connected. A fan and an atomizing nozzle are installed in the limiting cylinder 1, a threaded rod 201 is installed in the step distance adjusting cylinder 2, a spiral blade 202 is connected to the threaded rod 201, and both ends of the spiral blade 202 are threadedly connected to the threaded rod 201 and the two ends can move axially along the threaded rod 201 under the rotation of the step distance adjusting cylinder 2.

[0030] On the one hand, by arranging the spiral blade 202 in the air duct to form a spiral air duct, the spiral air duct can generate a certain centrifugal force, so that the drug particles are better dispersed and suspended in the air flow, which helps to improve the spraying effect, makes the drug easier to adhere to the target plants, and at the same time can guide the air flow to move forward spirally in a specific direction to ensure that the drug is evenly distributed in the target area during spraying.

[0031] On the other hand, by rotating the adjusting cylinder, the change of the step distance between the spiral blades 202 can be realized, and then the change of the spiral angle can be realized. For example, when the step distance increases, the axial movement speed of the air flow will relatively increase, the diffusion range in the horizontal direction will become wider, and the action range in the vertical direction will also increase, thereby expanding the coverage area of the medicament; conversely, when the spiral angle decreases and the step distance decreases, the air flow trajectory is more concentrated and the coverage area becomes smaller. When the plant height is relatively high, the pest distribution density and the leaf curtain density are relatively large, in order to make the medicament reach each part, the spiral angle and the step distance can be increased by making the upper and lower ends of the spiral blade 202 move away from each other, and then the air flow distribution can be optimized to improve the uniformity and coverage rate of spraying.

[0032] By means of this manual adjustment method, it is possible to adjust the spraying range and intensity according to actual needs, avoid the overuse and waste of pesticides, help reduce production costs, and improve economic benefits.

[0033] In order to realize the movement of both ends of the spiral blade 202 driven by the rotation of the pitch adjustment cylinder 2, the following structure is designed: An adjustment cylinder connecting frame 203 is installed on the inner wall of the pitch adjustment cylinder 2. The adjustment cylinder connecting frame 203 includes a sleeve 204 coaxially arranged with the threaded rod 201 and disposed outside the threaded rod 201. The sleeve 204 is provided with a guiding and limiting hole 205 whose length direction is along the axial direction of the sleeve 204. Threaded connectors 206 are provided at both ends of the spiral blade 202. The threaded connectors 206 are threadedly connected to the threaded rod 201 and can slide along the length direction of the guiding and limiting hole 205.

[0034] There are multiple guiding and limiting holes 205 and they are evenly arranged around the axis of the sleeve 204; the threaded connector 206 includes a connecting ring 207 slidably connected to the outer wall of the sleeve 204 and a connecting block 208 extending into the sleeve 204 through the guiding and limiting hole 205 and threadedly connected to the threaded rod 201. The connecting block 208 is fixed to the inner wall of the connecting ring 207 and can slide along the hole wall of the guiding and limiting hole 205 in the axial direction of the sleeve 204.

[0035] The adjustment cylinder connecting frame 203 further includes a frame body 209 connected between the sleeve 204 and the pitch adjustment cylinder 2. The frame body 209 includes a central circular ring portion 210 and connecting rod bodies 211 respectively fixed between the inner wall of the pitch adjustment cylinder 2 and the outer wall of the central circular ring portion 210 at both ends. The outer wall of the sleeve 204 is fixed to the inner wall of the central circular ring portion 210.

[0036] Under the action of the connecting frame body 209, the pitch adjustment cylinder 2 and the sleeve 204 form a whole. Therefore, when the pitch adjustment cylinder 2 rotates, it will drive the sleeve 204 to rotate synchronously. The rotation of the sleeve 204 will drive the threaded connector 206 to perform a threaded rotational movement on the threaded rod 201. Due to the setting of the guiding and limiting hole 205 on the sleeve 204, the threaded connector 206 can move up and down along the guiding and limiting hole 205 during the spiral movement, and then the relative movement of both ends of the spiral blade 202 towards or away from the middle is realized, so as to realize the adjustment of the pitch of the spiral blade 202.

[0037] The thread directions of the threaded connectors 206 at both ends of the spiral blade 202 are opposite, which can realize the movement of both ends of the threaded blade towards or away from each other.

[0038] In this embodiment, a limiting cylinder connecting frame 101 and a motor mounting frame 102 are arranged inside the limiting cylinder 1. The bottom of the threaded rod 201 is fixed on the limiting cylinder connecting frame 101. A fan motor for driving the fan to rotate is fixed on the motor mounting frame 102. The fan is arranged at the end of the limiting cylinder 1 away from the pitch adjustment cylinder 2. The atomizing nozzle is arranged on the side wall of the limiting cylinder 1. A nozzle mounting hole 121 for mounting the atomizing nozzle is arranged on the side wall of the limiting cylinder 1. The atomizing nozzle is mounted at the nozzle mounting hole 121, and the nozzle head extends into the limiting cylinder 1 and is located between the fan and the layout adjustment cylinder.

[0039] In this embodiment, the fan is a DC brushless motor with three blades. Each blade presents a streamline curve, so that the fan generates a stable and uniform air flow, so that the medicine sprayed by the atomizing nozzle is introduced into the pitch adjustment cylinder 2 under the action of the fan air flow, and then further exported under the action of the spiral blade 202, which can ensure that the medicine is evenly distributed on the grape plants during application.

[0040] In order to realize the rotational limit of the layout adjustment cylinder and the adjustment of the spraying angle of the air cylinder, the following mechanism is also provided: An annular step 103 with an L-shaped cross section is constructed on the inner wall of the limiting cylinder 1 and at the end face. The end of the pitch adjustment cylinder 2 is inserted on the annular step 103. A limiting component is arranged inside the limiting cylinder 1. The limiting component includes a limiting pin component 104 arranged on the inner wall of the limiting cylinder 1 and a limiting spring 105 sleeved on the limiting pin component 104. The limiting pin component 104 can be pressed against the end face of the pitch adjustment cylinder 2 by the step surface of the annular step 103 under the action of the limiting spring 105.

[0041] It also includes a U-shaped air cylinder turning frame 3. The air cylinder assembly is installed on the spraying vehicle through the air cylinder turning frame 3. The limiting cylinder 1 can be radially turned on the air cylinder turning frame 3. The limiting component also includes two relatively arranged rotating connectors 106. The rotating connector 106 includes a connecting cylinder body 107, a connecting column body 108 arranged in the connecting cylinder body 107 and capable of moving along the axial direction of the connecting cylinder body 107, and a driving spring 109 for driving the connecting column body 108 to move away from the limiting cylinder 1; one end of the connecting cylinder body 107 is fixed at the end of the air cylinder turning frame 3, and the other end is rotatably connected to the wall of the limiting cylinder 1; The limit pin assembly 104 includes an upper limit pin 110 and a lower limit pin 111 that are opposite and coaxially arranged. A limit spring 105 is disposed between the upper limit pin 110 and the lower limit pin 111. The upper limit pin 110 can abut against the end face of the pitch adjustment cylinder 2. The end of the connecting cylinder 108 extends into the limit cylinder 1, and an annular limit groove 112 and an unlocking long groove 113 that communicates with the annular limit groove 112 and whose length direction is along the axial direction of the rotating connector 106 are provided on the side wall of the end. The lower limit pin 111 can abut against the bottom surface of the annular limit groove 112 under the action of the limit spring 105. The bottom surface of the unlocking long groove 113 includes a communicating end 114 flush with the bottom surface of the annular limit groove 112 and an unlocking end 115 extending toward the end face of the end of the connecting cylinder 108. The bottom surface of the unlocking long groove 113 is inclined downward from the communicating end 114 to the unlocking end 115.

[0042] The setting of the limit assembly can achieve the rotational limit of the pitch adjustment cylinder 2, and can also achieve the flipping limit of the limit cylinder 1.

[0043] Specifically, in the limit state, after the pitch adjustment cylinder 2 is installed on the limit cylinder 1, the upper limit pin 110 and the lower limit pin 111 at both ends of the limit pin assembly 104 will respectively abut against the lower end face of the pitch adjustment cylinder 2 and the bottom surface of the annular limit groove 112 of the rotating connector 106 under the elastic force of the limit spring 105. On the premise that the limit spring 105 provides sufficient pre-tightening force, it can prevent the pitch adjustment cylinder 2 from rotating randomly under the action of the static friction force between the limit pin and the lower end face of the pitch adjustment cylinder 2, and only when a rotational force is applied to the pitch adjustment cylinder 2 can the pitch adjustment cylinder 2 rotate. In order to increase the limit stability, a friction-increasing gasket can also be provided between the lower end face of the pitch adjustment cylinder 2 and the step surface of the annular step 103. The gasket can be composed of a rubber annular sheet between two metal annular sheets, thereby further increasing the anti-rotational force of the pitch adjustment cylinder 2.

[0044] Similarly, the flipping limit method can be achieved by setting both the bottom surface of the annular limit groove 112 and the end of the lower limit pin 111 to be rough friction surfaces. Under the action of the limit spring 105, the end of the lower limit pin 111 abuts against the bottom surface of the annular limit groove 112, and the flipping limit of the limit cylinder 1 is achieved through the static friction force between the two, so that it will not flip randomly without external force.

[0045] In addition, in order to further improve its flipping limit stability, when the lower limit pin 111 is inserted into the annular limit groove 112, the side wall of the limit pin can be close to an interference fit with the side wall of the annular limit groove 112, and under the action of the driving spring 109, the two side walls can be abutted tightly, further increasing the anti-flipping force of the limit cylinder 1.

[0046] During the unlocking process, the operator first rotates the limit cylinder 1 forcefully, causing the limit cylinder 1 to flip around the rotating connecting piece 106. During the reverse process, the lower limit pin 111 will slide within the annular limit groove 112 until it moves to the position corresponding to the unlocking long groove 113. At this time, the connecting cylinder 108 can axially move relative to the connecting cylinder body 107 under the action of the driving spring 109, causing the lower limit pin 111 to move relative to the unlocking end 115 from the communication end 114 of the unlocking long groove 113. The limit spring 105 elongates and the initial pre-tightening force decreases. At this time, the step distance adjusting cylinder 2 can be rotated more easily to adjust the step distance and helix angle of the helical blade 202.

[0047] In this embodiment, in order to further enhance the effect of applying medicine in the air duct, a mechanism capable of controlling the fan speed is also provided to change the fan wind force. The specific structure is as follows: The limit cylinder 1 includes a flipping connection cylinder 116 connected to the air duct flipping frame 3 and a speed regulation cylinder 117 rotatably connected to the flipping connection cylinder 116. On the end face of the flipping connection cylinder 116 facing the speed regulation cylinder 117, there are a plurality of electrode contact mounting grooves 118 arranged circumferentially and evenly. Electrode contacts are installed in the electrode contact mounting grooves 118. On the end face of the speed regulation cylinder 117 facing the flipping connection cylinder 116, there is an electrode contact piece mounting groove 119, and an electrode contact piece is installed in the electrode contact piece mounting groove; it also includes a motor controller and a control power source electrically connected to the fan motor. Any two adjacent electrode contacts are connected in series to the control power source and the motor controller through a speed regulation circuit. The electrode contact piece can only connect two adjacent electrode contacts simultaneously under the rotation of the speed regulation cylinder 117. There is an electrode contact mounting groove 118 on the end face of the flipping connection cylinder 116, and a wire hole is opened at the bottom of the electrode contact mounting groove 118, which can realize the electrical connection between the electrode contact and the fan motor.

[0048] In addition, when the fan motor is installed on the motor mounting frame 102, the motor mounting frame 102 is fixed on the inner wall of the flipping connection cylinder 116. The fan motor can be installed in the flipping connection cylinder 116, and the fan can be installed in the speed regulation cylinder 117, which can avoid the inconvenience of wiring caused by the rotation of the fan motor.

[0049] The speed regulating cylinder 117 is inserted into the flip connection cylinder 116, and an annular groove 120 with an L-shaped cross section is provided on the outer wall of the speed regulating cylinder 117, and the electrode contact is provided on the bottom surface of the annular groove 120. The upper and lower end surfaces of the flip connection cylinder 116 are both constructed with annular steps 103, and the annular steps 103 on the upper and lower end surfaces are both provided with limit pin assemblies 104. The limit pin assemblies 104 on the upper and lower end surfaces are symmetrically arranged relative to the rotating connection piece 106 and have the same matching mode with the rotating connection piece 106; the limit pin assembly 104 on the lower end surface can be pressed against the end surface of the speed regulating cylinder 117 under the action of the limit spring 105. Through this structure, the same limit method as the step adjustment can be used to limit and unlock the rotation of the speed regulating cylinder 117.

[0050] In this embodiment, the motor controller includes a control circuit, and the control circuit is connected to an STM32 single-chip microcomputer. When the corresponding two adjacent electrode contacts are connected, the speed regulating branch composed of the motor controller, the control power supply and the corresponding speed regulating circuit is turned on, so that the motor controller can generate a corresponding operation signal, thereby completing the control of the speed of the motor.

[0051] Taking a specific implementation as an example, it has electrode contacts 1-8 arranged in sequence, and speed control circuits 1-8 arranged in sequence, and different electrical parameters (such as resistance values, capacitance values, etc.) are configured in the speed control circuits 1-8, wherein the speed control circuit 1-7 can be used to generate a speed signal for controlling the motor to run at different speeds, and the speed control circuit 8 can be used to generate a stop signal for controlling the motor to stop running.

[0052] During the budding and flowering stages, grapes have a lower tolerance to pesticides, so a lower rotation speed should be used to transport the pesticides with a gentle airflow to avoid damaging the plants. During the fruiting stage, grapes have a higher tolerance to pesticides, so the rotation speed can be appropriately increased to ensure that the pesticides penetrate the branches and leaves and reach the fruit.

[0053] When the pest distribution density is low, use a lower speed to apply the pesticide accurately; when the pest distribution density is high, the speed can be increased to quickly apply the pesticide over a large area to control the disease.

[0054] Before applying pesticides, the applicators will know in advance the growth stage, leaf density and pest distribution of the drugs being applied. Then, in the preparation stage of application, the applicators will run the sprayer into the spraying aisle and start the spraying mechanism in advance based on the relative spatial posture between the sprayer and the plants. The applicators can then adjust the spraying area, spray angle and spraying speed of the wind tube according to their experience. When it is adjusted to the state that the applicators think, they will run the sprayer for continuous spraying.

[0055] The manual adjustment method of this kind of air blower enables the pesticide applicator to flexibly adjust the spraying state according to the grape growth stage and the pest and disease situation, so as to adapt to different environments and requirements.

[0056] It is easy to understand that those skilled in the art can combine, split, recombine, etc. the embodiments of the present application based on one or several embodiments provided by the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0057] In summary, the above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the patent of the present invention.

Claims

1. A blower assembly, characterized in that: The invention comprises a limit cylinder (1) and a step adjustment cylinder (2) which are internally interconnected and rotatably connected, wherein a fan and an atomizing nozzle are installed in the limit cylinder (1), and a threaded rod (201) is installed in the step adjustment cylinder (2), and a spiral blade (202) is connected to the threaded rod (201), and both ends of the spiral blade (202) are threadedly connected to the threaded rod (201), and the two ends can move axially along the threaded rod (201) under the rotation of the step adjustment cylinder (2).

2. The air duct assembly according to claim 1, characterized in that: An adjusting cylinder connecting frame (203) is mounted on the inner wall of the step adjusting cylinder (2). The adjusting cylinder connecting frame (203) comprises a sleeve (204) coaxially arranged with the threaded rod (201) and arranged outside the threaded rod (201). The sleeve (204) is provided with a guide limit hole (205) arranged along the axial direction of the sleeve (204) in the length direction. Both ends of the spiral blade (202) are provided with threaded connectors (206). The threaded connectors (206) are threadedly connected to the threaded rod (201) and can slide along the length direction of the guide limit hole (205).

3. The air duct assembly according to claim 2, characterized in that: There are a plurality of guide limit holes (205) which are evenly arranged around the axis of the sleeve (204); the threaded connector (206) comprises a connection ring (207) slidably connected to the outer wall of the sleeve (204) and a connection block (208) which extends into the sleeve (204) through the guide limit hole (205) and is threadedly connected to the threaded rod (201); the connection block (208) is fixed to the inner wall of the connection ring (207) and can slide along the wall of the guide limit hole (205) in the axial direction of the sleeve (204).

4. The air duct assembly according to claim 1, characterized in that: A limiting cylinder connecting frame (101) and a motor mounting frame (102) are provided in the limiting cylinder (1); the bottom of the threaded rod (201) is fixed to the limiting cylinder connecting frame (101); a fan motor for driving the fan to rotate is fixed to the motor mounting frame (102); the fan is arranged at the end of the limiting cylinder (1) away from the step adjustment cylinder (2); and the atomizing nozzle is arranged on the side wall of the limiting cylinder (1).

5. The air duct assembly according to claim 4, characterized in that: An annular step (103) with an L-shaped cross section is formed on the inner wall of the limiting cylinder (1) and located at the end surface. The end of the step adjustment cylinder (2) is plugged into the annular step (103). A limiting assembly is provided in the limiting cylinder (1), the limiting assembly comprising a limiting pin assembly (104) arranged on the inner wall of the limiting cylinder (1) and a limiting spring (105) sleeved on the limiting pin assembly (104); the limiting pin assembly (104) can be pressed against the end surface of the step adjustment cylinder (2) via the step surface of the annular step (103) under the action of the limiting spring (105).

6. The air duct assembly according to claim 5, characterized in that: It also includes a U-shaped wind tube turning frame (3), on which the limiting cylinder (1) can be radially turned. The limiting assembly further comprises two rotating connecting members (106) arranged opposite to each other, the rotating connecting member (106) comprising a connecting cylinder (107), a connecting column (108) arranged in the connecting cylinder (107) and capable of axial movement along the connecting cylinder (107), and a driving spring (109) for driving the connecting column (108) to move in a direction away from the limiting cylinder (1); one end of the connecting cylinder (107) is fixed to the end of the wind cylinder flip frame (3), and the other end is rotatably connected to the cylinder wall of the limiting cylinder (1); The limit pin assembly (104) comprises an upper limit pin (110) and a lower limit pin (111) which are arranged oppositely and coaxially, a limit spring (105) is arranged between the upper limit pin (110) and the lower limit pin (111), and the upper limit pin (110) can be pressed against the end surface of the step adjustment cylinder (2); The end of the connecting column (108) extends into the limiting cylinder (1) and the side wall of the end is provided with an annular limiting groove (112) and an unlocking long groove (113) which is connected to the annular limiting groove (112) and is arranged along the axial direction of the rotating connecting member (106) in its length direction. The lower limiting pin (111) can be pressed against the bottom surface of the annular limiting groove (112) under the action of the limiting spring (105). The bottom surface of the unlocking long groove (113) includes a connecting end (114) flush with the bottom surface of the annular limiting groove (112) and an unlocking end (115) extending toward the end surface of the end of the connecting column (108). The bottom surface of the unlocking long groove (113) is arranged to be inclined downward from the connecting end (114) to the unlocking end (115).

7. The air duct assembly according to claim 6, characterized in that: The limiting cylinder (1) comprises a turning connection cylinder (116) connected to the wind cylinder turning frame (3) and a speed regulating cylinder (117) rotatably connected to the turning connection cylinder (116). A plurality of electrode contacts evenly arranged in the circumferential direction are provided on the end surface of the flip connection cylinder (116) facing the speed regulating cylinder (117), and an electrode contact sheet is provided on the end surface of the speed regulating cylinder (117) facing the flip connection cylinder (116); and a motor controller and a control power supply electrically connected to the fan motor are also included. Any two adjacent electrode contacts are connected in series between a control power supply and a motor controller via a speed regulating circuit, and the electrode contact pieces can simultaneously connect only two adjacent electrode contacts under the rotation of the speed regulating cylinder (117).

8. The air duct assembly according to claim 7, characterized in that: The upper and lower end surfaces of the flip connection cylinder (116) are both constructed with an annular step (103), and the annular steps (103) at the upper and lower end surfaces are both provided with a limit pin assembly (104). The limit pin assemblies (104) at the upper and lower end surfaces are symmetrically arranged relative to the rotating connection member (106) and cooperate in the same manner as the rotating connection member (106); the limit pin assembly (104) at the lower end surface can be pressed against the end surface of the speed regulating cylinder (117) under the action of a limit spring (105).

9. The air duct assembly according to claim 7, characterized in that: The speed regulating cylinder (117) is inserted into the flip connection cylinder (116), and an annular groove (120) with an L-shaped cross section is provided on the outer wall of the speed regulating cylinder (117), and the electrode contact piece is arranged on the bottom surface of the annular groove (120).

10. Variable spraying vehicle, characterized in that: It comprises the wind tube assembly according to any one of claims 1-9.

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