The backpack sprayer unit for small four-wheel tractors is a key equipment to improve the efficiency of agricultural plant protection. It has been continuously optimized in structural design, technical application and other aspects after long-term research.
The following is a detailed discussion on its core research contents, technical characteristics, current development status and future research directions:
Core Research on Structural and Matching Design
The core of the research on this type of sprayer unit lies in the rational matching of each component with the small four-wheel tractor to ensure stable operation and efficient application.
Specific research contents are as follows:
Power matching and transmission design: The unit usually relies on the small four-wheel tractor as the power source.
The research focuses on how to smoothly transmit the tractor's power to the liquid pump. At present, common transmission methods include PTO drive shaft connection and belt drive.
For example, some models use the PTO drive shaft to connect the tractor and the pressure pump, which can ensure the stability of the pump speed at 500 - 600r/min.
Meanwhile, researchers will also design clutch structures for the transmission system to realize the independent control of the sprayer, avoiding invalid operation during the tractor's traveling and saving energy.
Optimization of liquid pump and drug tank: The selection of the liquid pump directly affects the spraying effect. The current mainstream research tends to adopt double-cylinder diaphragm pumps because of their stable working pressure and uniform spraying.
In terms of the drug tank, the research covers two aspects: capacity and functional design.
The capacity of the drug tank is usually customized between 200L - 1000L according to the operation scale. In addition, the design of a jet mixing system in the tank is a key research point.
This system can force the mixing of the liquid medicine to avoid uneven concentration caused by precipitation of the liquid medicine and ensure the effect of pest control. The material of the drug tank and pipeline also belongs to the research scope. Special anti-corrosion materials such as PVC and corrosion-resistant steel pipes are widely used to prevent corrosion by chemical agents and extend the service life.
Spray rod and nozzle design: The spray rod is designed to be adjustable in height and foldable.
The spray width can reach 6m - 12m, and some models can even reach 24m. The foldable design is convenient for transportation and storage, and is also suitable for operation in different field environments such as dense orchards and large plain fields.
For nozzles, the research focuses on anti-dripping and adjustable functions.
Anti-dripping nozzles can prevent residual liquid medicine in the pipeline from dripping and causing waste or environmental pollution.
At the same time, each nozzle can be controlled independently, which can be flexibly turned on or off according to the density of crops.
Research on Key Functional and Performance ImprovementIn order to solve the problems such as uneven spraying and low utilization rate of liquid medicine in traditional spraying operations, researchers have carried out in-depth research on the functional upgrading of the unit:
Improvement of spraying coverage: It is a common problem that the back of crop leaves is difficult to be sprayed with liquid medicine. Aiming at this, the research introduces an air-assisted spraying technology.
The unit is equipped with an all-aluminum fan. While the liquid medicine is atomized by the high-pressure nozzle, the fan blows air to realize the secondary atomization of the liquid medicine.
At the same time, the wind makes the crop leaves shake, so that the front and back of the leaves can be evenly covered with the liquid medicine. Some foreign studies have gone further.
By combining two-stage spraying with a leaf-turning mechanism, two groups of spray units are set up to spray the upper and lower surfaces of leaves respectively, which can reduce the amount of liquid medicine used by 40% on the premise of ensuring the control effect.
Humanized operation optimization: The research also focuses on improving the operability of the unit.
For example, the distribution valve is arranged in a position convenient for the tractor driver to operate, so that the driver can adjust the spraying parameters without getting off the vehicle. In addition, the design of single-side control of the spray rod is also a research hotspot.
By controlling the valves on both sides separately, it can adapt to the operation needs of field edges and roadsides, reducing the waste of liquid medicine in non-crop areas.
Current Development Status
At present, the backpack sprayer unit for small four-wheel tractors has been widely used in the prevention and control of diseases and insect pests of dry and paddy field crops such as wheat, corn and rice, and has also been extended to the spraying operations of lawns, fruit trees and tea gardens. In terms of the market, the industry has formed a number of leading enterprises, and the market concentration is gradually improving.
The product quality is standardized. For example, the national standards such as Backpack Power Sprayer have standardized the performance and safety of such products.
In the application of rural areas in China, this type of unit has significantly improved the operation efficiency compared with manual spraying. It can complete the plant protection operation of a large area of farmland in a short time, which effectively solves the problem of labor shortage in rural areas.
Future Research Directions
Intelligent upgrading: With the development of smart agriculture, the integration of intelligent technologies will be a key research direction. It is expected to integrate GPS positioning, automatic drug dosage adjustment and fault self-diagnosis functions into the unit.
For example, the unit can automatically calculate the operation area through GPS, adjust the spraying amount according to the crop density, and send an alarm in time when the liquid pump fails or the liquid medicine is insufficient.
Green and low-carbon innovation: Faced with increasingly strict environmental protection policies, the research will focus on low-emission and energy-saving technologies.
For example, developing hybrid power-driven spray units to reduce fuel consumption and exhaust emissions.
At the same time, optimizing the atomization technology to further improve the utilization rate of liquid medicine, reduce the use of chemical agents, and reduce environmental pollution.
Adaptability improvement for complex scenarios: At present, the research on adapting to complex terrains such as hilly areas and dense orchards will be deepened. For example, developing a more compact body structure to enhance trafficability in dense planting areas.
In addition, researching nozzle technologies suitable for different crops.
For example, developing special nozzles with adjustable spray angles for fruit trees with large leaf layers to improve the pertinence and effectiveness of spraying.
