Preface of 0

Rotary tillage ridger is a kind of agricultural machinery deeply loved by farmers. Widely used in the cultivation of economic crops such as vegetables, flowers and flue-cured tobacco. It has the characteristics of rotary tillage, ditching and ridging at one time, high operation efficiency and good application prospect. According to the actual situation in Guangdong, a small rotary tillage ridger suitable for the planting characteristics and soil conditions of cash crops in Guangdong was designed, which was used in conjunction with the series of workers and peasants walking tractors. Jinfeng brand series walking tractors produced by Jiangmen Xinhui Nong Xin Machinery Co., Ltd. have nearly 250,000 sets in Guangdong. Therefore, the development of this machine can give full play to its advantages, effectively reduce the labor intensity of farmers, and improve the comprehensive utilization rate of agricultural machinery by agricultural machinery professionals.

1 overall design of rotary cultivator

1. 1 power supply selection

The designed 1GQS 1 10 rotary tiller is powered by jinfeng brand workers and peasants-18K walking tractor, with the engine power of 13.3 kW and various working speeds, and the highest speed can reach19.5km/h.

1.2 structure and working principle of the whole machine

1GQS- 1 10 rotary cultivator is mainly composed of frame, transmission system, rotary cultivator working parts and machine cover. The ridger is connected with the walking tractor through the frame, and the ridging blade rotating at high speed is used as the working part to break the soil and push it into a ridge shape. Its transmission system is shown in figure 1, and adopts side chain transmission mode. When working, the power output shaft of the tractor drives the bevel gear box 1, the power is transmitted to the sprocket box 3 through the transmission shaft 2, and then the rotary tillage ridging knife shaft 4 is driven to run through the chain drive, and the ridging knife 5 rotates to directly crush the soil, thus playing the role of rotary tillage and loosening the soil. At the same time, the ridging blades are spirally distributed from both sides, and when the blades rotate, the soil is pushed to the middle to form ridges, thus achieving the purpose of ridging.

1.3 motion parameter selection

Among the parameters of rotary tiller, the speed ratio and soil cutting pitch of rotary tiller are two important parameters that determine the operation quality and effect of rotary tiller. The design of this machine refers to the relevant calculation formula of rotary cultivator, and its rotary tillage speed ratio is also defined as:

Where r is the radius of rotation of the ridger blade, and 220 ram∞ is taken as the rotational angular velocity of the ridger shaft, rad/s, which is19.27-29.22 rad/s in the design; Vm is the forward speed of the unit, m/s, and VM = 0.7333m/s according to the forward speed of tractor II.

Substituting the relevant data, we can get =5.78- 8.77 from (1).

Similarly, the soil cutting interval s is defined as:

Where s is the soil cutting distance, cm; Z is the number of tools on the same rotating cutting surface.

According to the arrangement of knives on the ridging knife shaft, it is calculated by formula (2) according to Z=2 and S=7.88-ll .96 cm. From the numerical range of rotary tillage speed ratio and soil cutting pitch S, it can be seen that the parameter selection of rotary tillage ridger is reasonable and meets the agronomic requirements of general rotary tillage operation.

1.4 working width

Refer to the relevant empirical design formula of farming machinery;

Where b is the working width, m; P is the rated power of tractor, kW. The rated power of tractor is P= 13.3 kW, which is calculated by formula (3): b = 0.95-1.24m. According to the requirements of ridge width when planting vegetables, the design width of rotary tiller is1.1m.

1.5 rack

The frame part consists of bevel gear box, left bracket, sprocket box, transmission shaft and cover. The bevel gear box is connected with the rear axle of the walking tractor, and the ridging cutter shaft is installed at the lower end of the sprocket box. Bevel gear box and sprocket box housings are cast. The left support plate is made of ductile iron QT450- 10, and the transmission shaft is made of 40Cr.

1.6 ridging cutter shaft assembly

The ridging cutter shaft assembly is the main working part of rotary tillage ridger, which consists of ridging blade, cutter seat and ridging cutter shaft. 12 ridging knife, 6 left knives and 6 right knives, designed and installed on the knife shaft of ridger. Among them, the four middle knives (two on the left and two on the right) mainly play the role of breaking ground in the process of farming, and their connecting knife base and knife shaft are 7. Fillet welding; The eight knives outside (left 4 and right 4) not only play the role of breaking ground, but also play the role of pushing the broken ground to the middle and shaping it to form a ridge through the shaping plate, so the connecting knife seat and the knife shaft are 20. Fillet welding. Knife boxes with ridging blades are arranged in a double line on the knife shaft to improve the balance when the knife shaft rotates. Six knives on the left are arranged to the right, and six knives on the right are arranged to the left, and two spiral conveyors are formed on both sides. In the process of farming, the blade not only breaks the soil, but also pushes the soil to the middle, forming soil ridges. Fig. 2 is a schematic view of the cutter shaft of the rotary cultivator.

Due to the heavy workload of ridging, thicker steel plate is selected for the tool box, and the diameter of the ridging tool shaft is also appropriately increased. After many tests, Q235 -A steel plate with a thickness of 12 mm was selected for the ridging cutter box, and seamless steel pipe with a diameter of φ60×6mm was selected for the cutter shaft.

The role of ridging blade is not only to break the soil, but also to push the soil from both sides to the middle to form ridges. Therefore, the blade body is designed to be wider, the cutting edge is slightly curved, and it is shaped like a fan blade or a propeller blade. After many field tests, the specific dimensions of the blade are as follows: the height of the blade from the root to the top of the cutting edge is about 150 mm, the width of the blade from beginning to end is about 160 mm, the curved part of the cutting edge is 60 mm downward from the top of the cutting edge, and the arc radius is about100 mm. Because the rotary tillage ridging blade has larger radial force and axial force at the same time, it bears more load than the ordinary rotary tiller blade, so 65Mn steel plate with 6 mm thickness is selected as the material.

2 performance indicators and test results

2. 1 performance index

Table 1 shows the main performance indexes of the designed 1GQS- 1 10 rotary tiller.

2.2 test results

The rotary tillage ridger developed has passed the test of Guangdong Agricultural Machinery Appraisal Station. The test environment is sunny and the temperature is 16- 26. C, the relative humidity is 40%-60%; The soil is clay with water content of 26.3% and compactness of 127 kPa. The previous crop was rice, and the main vegetation was rice stubble and weeds; The working gear of the tractor is the second gear, and the working mode is one-step molding. The test results are shown in Table 2.

3 Conclusion

The designed small rotary tillage ridger has the characteristics of simple and compact structure, reliable performance and light weight. It can not only cultivate, break the soil, but also furrow and ridge, and can complete the operations of turning the soil, breaking the soil and leveling the border at one time, which is especially suitable for planting cash crops such as flue-cured tobacco, peanuts and vegetables.