CN111373888A

CN111373888A - Layered deep loosening mechanism and deep loosening method thereof

Info

Publication number: CN111373888A
Application number: CN202010322830.1A
Authority: CN
Inventors: 马星; 王世杰
Original assignee: Shenyang University of Technology
Current assignee: Shenyang University of Technology
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2020-07-07

Abstract

The invention provides a layered deep loosening mechanism, which comprises an elastic tooth type deep loosening piece for loosening upper-layer soil, wherein a rigid deep loosening piece for loosening lower-layer soil is arranged behind the elastic tooth type deep loosening piece along the deep loosening direction; the elastic tooth type subsoiling piece comprises a double-wing shovel and an elastic shovel handle, the double-wing shovel is fixed at the lower end of the elastic shovel handle, and the elastic shovel handle is an S-shaped elastic tooth type subsoiling shovel handle; the rigid deep scarification part comprises a rigid shovel head and a rigid shovel handle, and the rigid shovel head is fixed at the lower end of the rigid shovel handle; the shovel tip of the double-wing shovel is positioned above the shovel tip of the rigid shovel head; the elastic shovel handle is connected with the rigid shovel handle into a whole through a connecting piece; the invention provides a layered subsoiling mechanism which combines a spring tooth type subsoiling shovel with a rigid subsoiling shovel and can perform layered subsoiling on soil and reduce traction resistance.

Description

Layered deep loosening mechanism and deep loosening method thereof

Technical Field

The invention belongs to the technical field of agricultural machinery, and particularly relates to a layered deep scarification mechanism and a deep scarification method thereof.

Background

The subsoiler is a main working component of the whole subsoiler, and the structural forms and configurations of a subsoiler handle and a subsoiler shovel have direct influence on the quality of subsoiling operation; during subsoiling, the stress condition of a subsoiler directly influences the traction resistance and power consumption of the subsoiler, and also influences the disturbance range of soil after subsoiling, the soil breaking condition and the like; but subsoiler among the prior art is mostly rigid structure, and rigid structure's subsoiler drag resistance is great, the consumption is big to the horizontal not hard up scope in the in-process soil of subsoiling is great, and is great to the damage of crop root system, and the soil still can take place to overturn from top to bottom after the subsoiling, forms the soil structure of virtual reality down, is unfavorable for the growth of crops.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a layered subsoiling mechanism and a subsoiling method thereof, wherein the layered subsoiling mechanism combines a spring tooth type subsoiling shovel and a rigid subsoiling shovel, can perform layered subsoiling on soil and reduce traction resistance, and can break a plough layer, reduce the transverse loosening range of the soil and reduce damage to crop roots.

The technical scheme of the invention is as follows: a layered deep loosening mechanism comprises a spring tooth type deep loosening piece for loosening upper soil, wherein a rigid deep loosening piece for loosening lower soil is arranged behind the spring tooth type deep loosening piece along the deep loosening direction; the elastic tooth type subsoiling piece comprises a double-wing shovel and an elastic shovel handle, the double-wing shovel is fixed at the lower end of the elastic shovel handle, and the elastic shovel handle is an S-shaped elastic tooth type subsoiling shovel handle; the rigid deep scarification part comprises a rigid shovel head and a rigid shovel handle, and the rigid shovel head is fixed at the lower end of the rigid shovel handle; the shovel tip of the double-wing shovel is positioned above the shovel tip of the rigid shovel head; the elastic shovel handle is connected with the rigid shovel handle into a whole through a connecting piece.

The thickness of the S-shaped first bending of the elastic shovel shaft is larger than that of other positions.

The connecting piece is a horizontal connecting rod; the elastic shovel handle is fixed at one end of the connecting rod, and the other end of the connecting rod is detachably connected with the rigid shovel handle; the connecting rod is transversely provided with a plurality of first through holes for adjusting the front-back distance between the rigid shovel handle and the elastic shovel handle, the rigid shovel handle is longitudinally provided with a plurality of second through holes matched with the first through holes, and the second through holes with different heights are matched with the first through holes for adjusting the difference of the upper and lower tilling depths.

The rigid shovel head adopts a standard chisel-type shovel, and the rigid shovel handle adopts a standard column type subsoiler handle.

The double-wing shovel is a triangular double-wing shovel.

The upper end of the elastic shovel handle is fixedly connected with the block body, and the lower end of the elastic shovel handle is fixedly connected with one end, far away from the shovel tip, of the double-wing shovel; the block body is fixed at one end of the connecting piece, and the other end of the connecting piece is detachably connected with the rigid shovel handle.

The detachable connection mode is bolt connection, and a bolt sequentially penetrates through any one second through hole formed in the rigid shovel handle and any one first through hole formed in the connecting rod and is in threaded connection with a nut.

A deep scarification method of a layered deep scarification mechanism is characterized by comprising the following steps:

firstly, the method comprises the following steps: fixing the subsoiling mechanism on the frame and connecting the subsoiling mechanism with the traveling mechanism, and simultaneously ensuring that the elastic tooth type subsoiler is positioned in front of the rigid subsoiler;

secondly, the method comprises the following steps: adjusting the front-back distance between a rigid subsoiler of the subsoiling mechanism and the elastic tooth type subsoiler, and adjusting the tilling depth of the rigid subsoiler;

thirdly, the method comprises the following steps: starting a traveling mechanism, wherein the traveling mechanism drives an elastic tooth type subsoiler and a rigid subsoiler of the subsoiler to perform layered subsoiling on the soil;

fourthly: along with the forward movement of the subsoiling mechanism, the shovel tip of the elastic tooth type subsoiling shovel enters the soil to loosen the upper soil;

fifth, the method comprises the following steps: after the elastic tooth type subsoiling shovel subsoiles the upper soil, the rigid subsoiling shovel enters the soil to loosen the lower soil, and a fault appears in the soil at a certain distance from the lower surface of the rigid shovel head in the advancing process of the rigid subsoiling shovel, and the soil moves forward along with the rigid subsoiling shovel until the soil is broken.

The invention has the beneficial effects that:

1. the subsoiling mechanism comprises a spring tooth type subsoiling shovel and a rigid subsoiling shovel, can perform layered subsoiling on soil, and is used for loosening upper-layer soil and lower-layer soil; after the soil is layered and deeply loosened, the plough bottom layer structure is damaged, the state that the soil is compacted is changed, the permeability of the soil is improved, and a large amount of rainwater permeates; after the soil is layered and deeply loosened, the soil layer can be kept to be not disordered, the soil is properly scattered after ploughing, and the condition that soil blocks are emptied in the plough layer at the deeply loosened part can be avoided; due to the characteristics of layered deep scarification, the shallow soil and the deep soil are respectively operated by different subsoilers, so that the upper soil layer and the lower soil layer of the deeply scarified soil are not turned, a soil structure with a virtual upper part and a real lower part is formed, the positions of the surface soil and the bottom soil are not changed, and the bottom soil is thermalized in situ; the groove formed after the deep loosening can well store water and reduce evaporation, and has the functions of resisting drought, reducing disasters and keeping water and soil.

2. The invention adopts a layered deep scarification mode, can reduce the damage to crop roots, the narrow working part extrudes soil to crush the soil, and the soil fracture interfaces at the two sides of the deep scarification part are in a fan shape in a horizontal projection plane; the layered deep scarification can break the plough bottom layer, reduce the transverse loosening range of the soil and reduce the damage to the crop root system.

3. The invention adopts a layered deep loosening mode, which is beneficial to the absorption of the root system to the water, and after the soil is layered and deeply loosened, the permeability of the deep loosening part is strong, and a large amount of rainwater can permeate, so that the rainy season becomes the spring entropy. And is beneficial to the moisture balance of the soil.

4. The invention adopts a layered deep loosening mode, can reduce the traction resistance of the deep loosening machine, is influenced by the great firmness of the plough bottom layer from the aspect of power consumption of the deep loosening machine, has great power consumption during deep loosening operation, and designs a layered deep loosening mechanism in order to disperse the influence of soil firmness on the deep loosening traction resistance.

5. The elastic tooth type subsoiler of the invention adopts a self-excited vibration mode, and during cultivation, the subsoiler cuts soil with negative damping, thereby generating self-excited vibration.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the construction of the resilient blade handle of the present invention;

FIG. 3 is a schematic structural view of a double-wing shovel of the present invention;

FIG. 4 is a schematic view of a rigid shovel head according to the present invention;

FIG. 5 is a schematic view of the construction of the rigid blade handle of the present invention;

FIG. 6 is a graph showing the variation of the drag force of the subsoiler with the forward speed of the machine in accordance with the present invention;

FIG. 7 is a curve of the variation of the drag force of different subsoilers of the present invention with the depth of cultivation;

FIG. 8 is a time history of the vibratory acceleration signals of different subsoilers of the present invention;

FIG. 9 is a time domain plot of the vibration acceleration of the snap-action subsoiler of the present invention;

FIG. 10 is a time domain plot of the vibration speed of the present invention snap-action subsoiler;

FIG. 11 is a time domain plot of the vibratory displacement of the present snap-action subsoiler;

FIG. 12 is a time domain plot of the vibratory acceleration of the rigid subsoiler of the present invention;

FIG. 13 is a time domain plot of the vibratory speed of the rigid subsoiler of the present invention;

FIG. 14 is a time domain plot of the vibratory displacement of the rigid subsoiler of the present invention;

FIG. 15 is a frequency domain plot of the vibratory displacement of the present invention of the snap-action subsoiler;

FIG. 16 is a frequency domain plot of the vibratory displacement of the rigid subsoiler of the present invention;

FIG. 17 is a magnitude-frequency curve of the vibration acceleration self-power spectrum of the elastic tooth type subsoiler of the present invention;

FIG. 18 is a magnitude-frequency curve of the vibration acceleration self-power spectrum of the rigid subsoiler of the present invention;

FIG. 19 shows the deformation of the latch-type subsoiler of the present invention during tillage;

FIG. 20 shows the soil subsoiling with the rigid subsoiler of the present invention for 1.7 s;

FIG. 21 illustrates the soil subsoiling process of the rigid subsoiler of the present invention for 3.5 s;

FIG. 22 shows the soil subsoiling with the rigid subsoiler of the present invention for 5.2 s;

FIG. 23 illustrates the soil subsoiling process of the rigid subsoiler of the present invention for 6.8 s;

FIG. 24 illustrates the soil subsoiling with the rigid subsoiler of the present invention for 8.4 s;

FIG. 25 is a view of the soil subsoiling with the rigid subsoiler of the present invention for 9.4 s;

FIG. 26 is a view of the present invention showing the subsoiling procedure of the elastic tooth type subsoiler for 1.7 s;

FIG. 27 shows the subsoiling procedure of the present invention with the elastic tooth type subsoiler for 3.5 s;

FIG. 28 is a view of the subsoiling procedure of the present invention with the elastic tooth type subsoiler for 5.2 s;

FIG. 29 shows the subsoiling procedure of the present invention with the elastic tooth type subsoiler for 6.8 s;

FIG. 30 shows the subsoiling procedure of the 8.4s elastic tooth type subsoiler of the present invention with respect to soil;

FIG. 31 shows the soil subsoiling process of the spring-tooth subsoiler of the present invention at 9.4 s;

FIG. 32 is a graph of the equivalent stress change of a rigid subsoiler at 2.5s in accordance with the present invention;

FIG. 33 is a graph of the equivalent stress change of a rigid subsoiler at 5.0s in accordance with the present invention;

FIG. 34 is a graph of the equivalent stress change of a rigid subsoiler at 7.5s in accordance with the present invention;

FIG. 35 is a graph showing the equivalent stress change of a rigid subsoiler at 9.5s according to the present invention;

FIG. 36 is a graph showing the equivalent stress variation of the latch-type subsoiler for 2.5s according to the present invention;

FIG. 37 is a graph showing the equivalent stress variation of the snap-action subsoiler at 5.0s according to the present invention;

FIG. 38 is a graph showing the equivalent stress variation of the latch-type subsoiler for 7.5s in accordance with the present invention;

FIG. 39 is a graph showing the equivalent stress variation of the latch-type subsoiler at 9.5s according to the present invention;

FIG. 40 is a time history of the drag resistance of the rigid subsoiler of the present invention;

FIG. 41 is a time history of drag resistance of the present snap-action subsoiler;

FIG. 42 is an overall traction resistance time history curve of the present invention;

FIG. 43 is a cross-sectional view of a soil loosening trench according to the present invention.

Description of reference numerals:

9. a double-wing shovel; 10. an elastic shovel shaft; 11. a rigid shovel head; 12. a rigid dipper handle; 13. a connecting member; 14. and (3) a block body.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Example 1:

the embodiment provides a layered deep loosening mechanism which comprises an elastic tooth type deep loosening piece for loosening upper-layer soil, wherein a rigid deep loosening piece for loosening lower-layer soil is arranged behind the elastic tooth type deep loosening piece along the deep loosening direction; the elastic tooth type subsoiling piece comprises a double-wing shovel 9 and an elastic shovel handle 10, the double-wing shovel 9 is fixed at the lower end of the elastic shovel handle 10, and the elastic shovel handle 10 is an S-shaped elastic tooth type subsoiling shovel handle; the rigid subsoiling piece comprises a rigid shovel head 11 and a rigid shovel handle 12, and the rigid shovel head 11 is fixed at the lower end of the rigid shovel handle 12; the shovel tip of the double-wing shovel 9 is positioned above the shovel tip of the rigid shovel head 11; the elastic shovel shaft 10 is connected with the rigid shovel shaft 12 into a whole through a connecting piece 13.

Further, the thickness of the first S-shaped bend of the resilient blade handle 10 is greater than the thickness at other positions.

Further, the connecting piece 13 is a horizontal connecting rod; the elastic shovel handle 10 is fixed at one end of the connecting rod, and the other end of the connecting rod is detachably connected with the rigid shovel handle 12; the connecting rod is transversely provided with a plurality of first through holes for adjusting the front-back distance between the rigid shovel handle 12 and the elastic shovel handle 10, the rigid shovel handle 12 is longitudinally provided with a plurality of second through holes matched with the first through holes, and the second through holes with different heights are matched with the first through holes for adjusting the difference of the upper and lower tilling depths.

Further, the rigid shovel head 11 is a standard chisel type shovel, and the rigid shovel handle 12 is a standard column type subsoiler handle.

Further, the double-wing shovel 9 is a triangular double-wing shovel.

Further, the upper end of the elastic shovel handle 10 is fixedly connected with the block 14, and the lower end of the elastic shovel handle 10 is fixedly connected with one end of the double-wing shovel 9 far away from the shovel tip; the block body 14 is fixed at one end of the connecting piece 13, and the other end of the connecting piece 13 is detachably connected with the rigid shovel shaft 12.

Further, the detachable connection mode is bolt connection, and a bolt sequentially penetrates through any one second through hole formed in the rigid shovel shaft 4 and any one first through hole formed in the connecting rod and is in threaded connection with a nut.

A deep scarification method of a layered deep scarification mechanism comprises the following steps:

for the layered subsoiling process of the elastic tooth type subsoiling shovel, the influence of the loosening range of the double-wing shovel is exerted, and the soil on the upper part and the lower part of the shovel head is influenced in a certain range. Because the double-wing shovel type bends downwards, receives the effect of soil adhesion, along with the antedisplacement of subsoiler, the soil of double-wing shovel lower part is the back that adheres at the double-wing shovel earlier, and is lifted up, when lifting to a take the altitude, and the soil of shovel back loses the effect of shovel, receives the influence of gravity, moves downwards again. Because the adhesion of soil is great and receive the influence of shovel type, the partly soil that is close subsoiler bottom receives the ascending effort of subsoiler stronger, and big crack appears in the soil bottom. The elastic tooth type subsoiler has a larger soil entering angle, so that the longitudinal influence range of soil is large, and the subsoiling range is larger;

The layered subsoiling mechanism comprises a spring tooth type subsoiling shovel and a rigid subsoiling shovel, can perform layered subsoiling on soil, and is used for loosening upper-layer soil and lower-layer soil; after the soil is layered and deeply loosened, the plough bottom layer structure is damaged, the state that the soil is compacted is changed, the permeability of the soil is improved, and a large amount of rainwater permeates; after the soil is layered and deeply loosened, the soil layer can be kept to be not disordered, the soil is properly scattered after ploughing, and the condition that soil blocks are emptied in the plough layer at the deeply loosened part can be avoided; due to the characteristics of layered deep scarification, the shallow soil and the deep soil are respectively operated by different subsoilers, so that the upper soil layer and the lower soil layer of the deeply scarified soil are not turned, a soil structure with a virtual upper part and a real lower part is formed, the positions of the surface soil and the bottom soil are not changed, and the bottom soil is thermalized in situ; the groove formed after deep loosening can well store water, reduce evaporation, and has the functions of resisting drought, reducing disaster and keeping water and soil;

according to the layered subsoiling mechanism, the mode that the elastic tooth type subsoiling shovel and the rigid subsoiling shovel are combined is adopted, the S-shaped characteristic of the elastic shovel handle is influenced by factors such as soil resistance, and the elastic shovel handle swings to the maximum at the tooth point and vibrates to the strongest;

the front-back distance between the elastic tooth type subsoiler and the rigid subsoiler can be simply and conveniently adjusted, and the difference of the up-down tilling depth can be adjusted; the traction resistance is directly influenced by the difference of the tilling depth, and the traction resistance is influenced by different tilling depths and different advancing speeds.

Firstly, the test research of the layered subsoiling mechanism comprises the following steps:

the elastic tooth type subsoiling shovel and the rigid subsoiling shovel are used as research objects, traction resistance signals and vibration signals of the two subsoiling shovels under the same working condition are collected and processed and analyzed, and then working performance and subsoiling effect of vibration and non-vibration type subsoiling parts are compared, so that theoretical basis is provided for design optimization of the layered subsoiling mechanism.

The test contents are as follows:

(1) and measuring the working resistance of the elastic tooth type subsoiler and the rigid subsoiler during subsoiling. Through the measurement of the traction resistance and the vertical force when the elastic tooth type subsoiler and the rigid subsoiler are used for subsoiling, the stress conditions of different subsoilers are analyzed, and the components of the subsoiler can be reasonably configured.

(2) And measuring vibration parameters of the elastic tooth type subsoiler and the rigid subsoiler. Through analyzing the vibration conditions of different subsoilers, the influence of vibration on subsoiling effect and traction resistance is discussed, and a theoretical basis is provided for the design of the vibrating subsoiler.

(3) And detecting the subsoiling effect of the elastic tooth type subsoiler and the rigid subsoiler. The subsoiling effect of different subsoilers is compared by testing the ploughing depth, the section area and the like of different subsoilers after subsoiling.

The test materials and methods were as follows:

(1) introduction of soil tank test trolley for test

The soil tank test is carried out in the agricultural machinery soil tank laboratory of the institute of agriculture and mechanization, Liaoning province, the length of the soil tank is 30m, the width is 2.95m, the soil tank is filled with sandy loam, and the depth is 0.4 m. The test power is electric four-wheel drive soil box test trolley, and the test trolley runs on the rails on two sides of the rails. The test vehicle mainly comprises a frame, a driving wheel, a main rotating system, a control cabinet, a hydraulic pump station, a brake and the like. The test vehicle adopts a variable frequency motor driving mode to realize stepless speed regulation within the speed range of 0.3-10 km/h. The maximum traction force of the test vehicle is 1.5t, the maximum speed is 10km/h, and the speed requirement of most of domestic agricultural implement components can be met. As most of test objects of the test vehicle are agricultural machine parts or small-sized machines, the suspension device is designed to be a semi-split type and is provided with a standard tractor suspension device, and the performance of the suspension device completely meets the test requirements of the parts. The power output shaft adopts a variable frequency motor and a hydraulic pump station driving motor to regulate the speed and provide power for the test of the rotating working part. The soil tank test vehicle is provided with test monitoring software, can monitor the running speed, the torque of a power output shaft, the rotating speed and the power of the soil tank vehicle in real time, and collects, displays and stores the accessed sensor data.

(2) Introduction of test System for testing

The main test instruments are: XL1101 strain type acceleration sensor manufactured by cooperative science and technology development Limited in Qinhuang island, BLR-1 strain type acceleration sensor manufactured by Shanghai east China electronic instrument factory, VIB2008 vibration tester manufactured by Beijing Langsu test technology Limited, TZS-II soil moisture tester manufactured by Hangzhou Topu instrument Limited, SC-900 soil firmness tester manufactured by Beijing Ward accurate science and trade Limited, notebook computer, etc. And designing a test system according to the test requirements of the deep-loosening part.

The acquisition of the vibration acceleration signal converts an analog signal into a digital signal through a strain type acceleration sensor, and a vibration tester acquires the digital signal and inputs the digital signal into a computer for outputting by using a C _ DAS comprehensive test system. The resistance signals are respectively detected by the pulling pressure sensors at different positions on the force measuring frame to detect the traction resistance and the vertical resistance of the subsoiler, and the soil tank test vehicle monitoring system is used for collecting, displaying and storing the signals.

The test procedure was as follows:

(1) preparation test:

in order to simulate the actual farmland soil condition, the physical parameters of the soil are close to those of the farmland as much as possible, and the soil in the soil tank needs to be cleared up so that the soil parameters meet the test requirements. The soil type selected in the soil tank is sandy loam, and the soil quality is uniform. The loam contains a proper amount of clay grains, sand grains and powder grains, has the advantages of clay and sandy soil in nature, is ideal soil for agriculture and cultivation, is one kind of loam, has deep soil layer, light soil texture, proper underground water level and high soil nutrient content, has no saline alkali or slight saline alkali in the soil, and is suitable for the growth of crops. And hanging the land leveling device on a rear suspension frame of the soil tank test vehicle, and leveling the soil in the soil tank by the traction of the soil tank test vehicle. The average soil moisture in the test soil tank is 14.8%, and the average soil firmness at the position of 30cm is 968 kPa.

(2) And measuring the working resistance of the elastic tooth type subsoiler and the rigid subsoiler during subsoiling.

Through the test to traction resistance and vertical resistance, can weigh the energy consumption of different subsoilers in the subsoiling process to and the atress distribution condition of subsoiler.

The force measuring frame is hung on a rear hanging frame of the soil tank test trolley, 6 tension and pressure sensors are arranged on the force measuring frame, 2 of the tension and pressure sensors are used for testing the horizontal force of the traction device, 3 of the tension and pressure sensors are used for testing the vertical force, and 1 of the tension and pressure sensors is used for testing the lateral force.

During resistance test, the elastic tooth type subsoiler and the rigid subsoiler are respectively arranged on the rear suspension rod of the force measuring frame. The acting force of the elastic tooth type subsoiler and the rigid subsoiler is collected by a tension pressure sensor on the force measuring frame and stored in the monitoring software of the soil tank car. The elastic tooth type subsoiler handle is provided with a double-wing shovel, and the rigid subsoiler is provided with a chisel-shaped shovel. The elastic tooth type subsoiler and the rigid subsoiler are respectively connected with the force measuring frame. During the test, the subsoiling performance of different subsoiling shovel handles is analyzed by changing the advancing speed of the soil tank car and the soil penetration depth of the subsoiling shovel, and then the application conditions of the different subsoiling shovel handles are judged.

(3) And measuring vibration parameters of the elastic tooth type subsoiler and the rigid subsoiler.

In the tillage process, due to the S-shaped characteristic of the elastic shovel handle and the influence of factors such as soil resistance and the like, the elastic shovel handle swings to the maximum at the tooth tip and vibrates most strongly. Strain type acceleration sensors are respectively arranged at the shovel tips of the elastic tooth type subsoiler and the rigid subsoiler. The vibration characteristics of the two subsoilers are analyzed by measuring the vibration parameters of the two subsoilers.

The working resistance test results and analyses were as follows:

(1) single factor assay analysis:

1. the effect of the forward speed of the different subsoiler handles on the drag resistance.

The forward speeds of the first gear to the fifth gear of the tractor are 0.7m/s, 1m/s, 1.5m/s, 2m/s and 3m/s respectively. The cultivation speed is not suitable to be too fast according to the needs of the actual cultivation situation. The traction resistance of the elastic tooth type subsoiler and the rigid subsoiler is tested when the forward speed is 1m/s, 1.5m/s, 2m/s, 2.5m/s and 3m/s and the farming depth is 25cm, and the test time is 10 s. The traction resistance obtained by the test was analyzed to find the average value, and the results are shown in Table 3-1

TABLE 3-1 Effect of farming speed on traction resistance

Tab.3-1The influence of tillage speed on tractive resistance

According to Table 3-1, the drag force of the subsoiler is plotted against the forward speed of the machine, as shown in FIG. 6. As can be seen, the drag resistance increases with increasing forward speed, the drag resistance of the rigid subsoiler increases substantially linearly, while the drag resistance of the snap-action subsoiler changes more slowly. When the advancing speed is the same, the traction resistance of the rigid subsoiler is larger than that of the elastic tooth type subsoiler.

2. The influence of the depth of cultivation of different subsoiler handles on the drag resistance.

The traction resistance of the elastic tooth type subsoiler and the rigid subsoiler is tested when the farming depth is 15cm, 20cm, 25cm and 30cm and the advancing speed is 1m/s, and the test time is 10 s. The traction resistance obtained by the test was analyzed, and the average value was found, and the results are shown in Table 3-2.

TABLE 3-2 Effect of tilling depth on traction resistance

Tab.3-2Influence of cultivating depth on tractive resistance

According to Table 3-2, the curves of the subsoiler drag force as a function of tilling depth are plotted, as shown in FIG. 7. As can be seen, the drag resistance increases with increasing tilling depth. The traction resistance changes slowly at the position of 15-20 cm, because the soil on the layer is loose, and the traction resistance does not change greatly along with the tilling depth. At the position of 20-30 cm, the traction resistance of the rigid subsoiler is rapidly increased, which is caused by overlarge soil compactness of the layer, while the traction resistance of the elastic tooth type subsoiler is slowly changed, which is caused by the overlarge soil compactness of the layer, large soil compactness, extreme deformation of the elastic tooth, and incapability of penetrating into the layer of soil, but working at the position of 20cm or above, so that the elastic tooth type subsoiler is not suitable for the overlarge soil.

3. Stress analysis of different subsoilers

Under the condition that the advancing speed and the tilling depth are the same, the stress conditions of the traction resistance and the vertical resistance of the elastic tooth type subsoiler and the rigid subsoiler are analyzed, and the application conditions and the subsoiling effect of the elastic tooth type subsoiler and the rigid subsoiler are researched.

Comparing the statistical results of the impact of the elastic tooth subsoiling blade and the rigid subsoiling blade on the subsoiling performance (table 3-3), when the forward speed is 1m/s and the working depth is 25cm, the traction resistance of the elastic tooth subsoiling blade is reduced by 9.95% compared with the rigid subsoiling blade, the standard deviation is reduced from 38.52 to 30.22, and the coefficient of variation is reduced from 0.077 to 0.067. The elastic tooth type subsoiler has obvious resistance reducing effect compared with a rigid subsoiler, and the working stability is also improved. The vertical force of the elastic tooth type subsoiler is reduced by 94.42% compared with that of a rigid subsoiler, and the standard deviation is reduced from 43.43 to 31.18, which shows that the resistance of the elastic tooth type subsoiler in the vertical direction is obviously reduced compared with that of the rigid subsoiler, but the coefficient of variation is improved from 0.051 to 0.659, because the elastic tooth type subsoiler is influenced by the soil resistance when working in soil, the elastic tooth type subsoiler deforms to release elastic energy, and the disturbance range of the elastic tooth type subsoiler in the vertical direction is larger. The included angle between the total acting force of the elastic tooth type subsoiler on soil and the horizontal plane is larger than that of the rigid subsoiler, which also shows that the acting force of the elastic tooth type subsoiler in the vertical direction is more obvious. From the soil failure effect, the soil range disturbed by the elastic tooth type subsoiler is larger than that of a rigid subsoiler, the subsoiling specific resistance is reduced by 14.52%, and the rigid subsoiler has a better subsoiling effect.

TABLE 3-3 influence of the elastic tine subsoiler and of the rigid subsoiler on subsoiling performance

Tab.3-3Different performance of two subsoilingshovel

Soil disturbances can be characterized as two main areas, deep and near surface areas. In deep areas, the soil breaks up into small pieces. In the near-surface area, the soil is broken to form large clods. The soil plough layer is positioned about 20cm below the ground surface, and the hardness of the soil plough layer is about 3 times of that of the plough layer. The purpose of deep scarification is to break the plough bottom layer and loosen the soil. From the above analysis, the vibration of the elastic tooth type subsoiler in the vertical direction is unstable, and the released elastic energy is not enough to achieve the energy required for loosening the plough bottom layer soil, so that the elastic tooth type subsoiler is more suitable for loosening the surface layer soil. Therefore, for the soil in the near-surface area, namely 0-20 cm below the ground surface, the elastic tooth type subsoiler can be used for crushing the soil firstly, and the rigid subsoiler can be used for subsoiling the plough bottom soil above 20cm below the ground surface.

(2) Orthogonal assay analysis:

orthogonal experimental design is a method for scientifically arranging and analyzing multi-factor experiments by using orthogonal tables. Orthogonal tests can uniformly select a few test schemes with strong representativeness from all test schemes, and the test results of the few test schemes are analyzed to deduce a better scheme. Through further analysis of the test results, the importance degree of the influence of each test factor on the test results, the influence trend of each factor on the test results and the like can be obtained.

In order to further analyze the influence of the shovel type, the tilling depth and the advancing speed on the traction resistance, the power consumption and the subsoiling effect, a three-factor two-level orthogonal test is carried out, and the analysis of the test result is carried out by using EXCEL.

1. Test factors and test indexes

The test factors are the type of the shovel shaft, the advancing speed of the machine and the tilling depth, and each factor is two levels. The test indexes are traction resistance and soil failure area after deep scarification, power consumption and deep scarification specific resistance are calculated according to the traction resistance and the soil failure area, and the traction resistance, the power consumption and the deep scarification specific resistance are used as test indexes. The levels of test factors are shown in tables 3-4.

TABLE 3-4 factor level table

Tab.3-4Table of level of factors

2. Test protocol and test results

The L8(27) orthogonal table was chosen for testing, and the protocol and results are shown in tables 3-5.

Tables 3-5 test protocols and results

Tab.3-5Test scheme and results

3. Range analysis of test results

The test indexes of traction resistance, power consumption and deep scarification specific resistance are respectively subjected to range analysis, and the analysis results are shown in tables 3-6, 3-7 and 3-8.

When the traction resistance is used as a test index, the influence of three factors on the traction resistance is considered to be in sequence from major to minor, namely tillage depth C, shovel handle type A, advancing speed B, interaction A × C of the shovel handle type and the tillage depth, interaction A × B of the shovel handle type and the advancing speed, and interaction B × C of the advancing speed and the tillage depth, wherein the optimal combination is A₁B₁C₁When the elastic tooth type subsoiler handle is selected, the advancing speed is 1m/s and the tilling depth is 20cm, the traction resistance is minimum.

When power is used as a test index, the influence of three factors on traction resistance is considered to be in the sequence from primary to secondary, namely advancing speed B, tilling depth C, shovel handle type A, interaction of the shovel handle type and the tilling depth A × C, interaction of advancing speed and the tilling depth B × C, interaction of the shovel handle type and the advancing speed A × B, and the optimal combination is A₁B₁C₁Namely, when the selection of the elastic tooth type subsoiler handle is carried out, the advancing speed is 1m/s, and the tilling depth is 20cm, the power consumption is minimum.

When the deep bulk specific resistance is taken as a test index, the influence of the three factors on the traction resistance is considered from primary to secondaryThe sequence is, in order, a type of blade handle A, a depth of field C, a speed B, an interaction of type of blade handle and depth of field A × C, an interaction of forward speed and depth of field B × C, and an interaction of type of blade handle and forward speed A × B₁B₁C₁Namely, when the selection of the elastic tooth type subsoiler handle is carried out, the advancing speed is 1m/s, and the tilling depth is 20cm, the subsoiling specific resistance is minimum.

From the analysis, when the spring-tooth type subsoiler is selected, the advancing speed is 1m/s, and the tilling depth is 20cm, the traction resistance, the power consumption and the subsoiling specific resistance all have the minimum value. The elastic tooth type subsoiler has better subsoiling and drag reduction effects than a rigid subsoiler, but the tilling depth is shallower.

TABLE 3-6 ANALYSIS TABLE FOR TRACTION RESISTANCE POLARITY

Tab.3-6Analysis of tractive resistance range

TABLE 3-7 Power range analysis table

Tab.3-7Analysis of power range

TABLE 3-8 deep apparent density resistance range analysis table

Tab.3-8Analysis of specific resistance range

4. Analysis of variance of test results

And through analysis of variance on the test results, the size of the error is estimated, and the importance degree of the influence of the test results of all factors is accurately estimated. The variance analysis is carried out by using Excel, the extreme difference analysis is respectively carried out on the traction resistance, the power consumption and the deep apparent density resistance of the test indexes, and the analysis results are shown in tables 3-9, 3-10 and 3-11.

When the traction resistance is used as a test index, the mean square of A × B and B × C is smaller than the mean square of the error 309.94, and the error is included to form a new error, and when the given significance level α is 0.05, the F value is compared with a critical value, so that the traction resistance is very significantly influenced by the type A of the shovel handle, the advancing speed B and the tilling depth C, the significance level is 0.01, the traction resistance is significantly influenced by the interaction A × C of the type A of the shovel handle and the tilling depth, the significance level is 0.05, and the traction resistance is not influenced by the interaction A × B of the type A of the shovel handle and the advancing speed A × C of the advancing speed and the tilling depth.

When power is taken as a test index, the mean square value of each factor is greater than the mean square value of error 285.9, so each factor has an effect on power, for a given significance level of α -0.05, the forward speed B has a significant effect on power, with a significance level of 0.05.

When the specific resistance is taken as a test index, the mean square of A × B is equal to the mean square of the error of 0.001, and the mean square of A × B is classified into the error to form a new error, wherein for a given significance level α of 0.05, the shovel handle type A has a very significant influence on the specific resistance, the significance level is 0.01, and the advancing speed B and the tilling depth C have significant influences on the specific resistance, and the significance level is 0.05.

TABLE 3-9 traction resistance variance analysis table

Tab.3-9Variance analysis on tractive resistance

F_0.01(1,3)＝34.12

F_0.05(1,3)＝10.13

TABLE 3-10 Power ANOVA TABLE

Tab.3-10Analysis of power variance

F_0.01(1,1)＝4052.18

F_0.05(1,1)＝161.45

TABLE 3-11 analysis of specific resistance and variance

Tab.3-11Analysis of specific resistance range

F_0.01(1,2)＝98.50

F_0.05(1,2)＝18.51

Vibration characteristic analysis:

(1) time domain analysis

And processing and analyzing the vibration signal by using Vib' SYS vibration signal analysis software. Under the working conditions that the tillage depth is 25cm and the tillage speed is 1m/s, vibration acceleration tests are carried out at the tips of the elastic tooth type subsoiler and the rigid subsoiler, and as the soil tank wagon can generate an impact effect when being started and stopped, the test result is influenced, so that the more stable 10s in the tillage process is intercepted and analyzed. FIG. 8 shows the time histories of the vibratory acceleration signals for two subsoilers, where the dotted line is the time history of the vibratory acceleration signal at the point of the resilient tine subsoiler and the solid line is the time history of the vibratory acceleration signal at the point of the rigid subsoiler. As can be seen from the figure, the vibration of the two shovels belongs to random vibration, and the fluctuation at the point of the elastic tooth type subsoiler is obviously larger than that of the rigid subsoiler. The average value of the vibration acceleration at the shovel tip of the elastic tooth type subsoiler is 0.11m/s2, while the average value of the vibration acceleration at the shovel tip of the rigid subsoiler is only 0.07m/s2

The acceleration signal a (t) is integrated once to obtain the velocity v (t), and the velocity signal is integrated once to obtain the displacement s (t). Due to the influence of zero drift and the non-zero integration initial value, an integration error can be generated, and a direct current component can be removed through high-pass filtering. High pass filtering is performed before each integration, with the filtering frequency from 0.5Hz to 500 Hz. And the vibration acceleration waveform is subjected to twice integration and three times of high-pass filtering to obtain a vibration displacement waveform. Fig. 9 shows the time domain plot of the vibration acceleration of the snap-action subsoiler, fig. 10 shows the time domain plot of the vibration speed of the snap-action subsoiler, fig. 11 shows the time domain plot of the vibration displacement of the snap-action subsoiler, fig. 12 shows the time domain plot of the vibration acceleration of the rigid subsoiler, fig. 13 shows the time domain plot of the vibration speed of the rigid subsoiler, and fig. 14 shows the time domain plot of the vibration displacement of the rigid subsoiler. Within the 10s range examined, the maximum value of the vibration speed of the elastic tooth subsoiler is 0.763m/s, and the maximum value of the vibration speed of the rigid subsoiler is 0.176m/s, which is only 23.07% of that of the elastic tooth subsoiler. The maximum value of the vibration displacement of the elastic tooth type subsoiler is 0.274m, the maximum value of the vibration speed of the rigid subsoiler is 0.064m, and the maximum value is only 23.36% of that of the elastic tooth type subsoiler. The vibration speed and the vibration displacement of the rigid subsoiler are far smaller than those of the elastic tooth type subsoiler, which shows that the elastic tooth type subsoiler vibrates under the action of elastic force when in work, and the vibration of the rigid subsoiler is very small.

(2) Frequency domain analysis

The method of applying fast fourier transform transforms the time domain description of the vibration signal into a frequency domain description. As can be seen from the frequency domain plot of the vibratory displacement of the snap subsoiler of FIG. 15 and the frequency domain plot of the vibratory displacement of the rigid subsoiler of FIG. 16, the maximum amplitude occurs for both shovels at a frequency of 0.49 Hz. The maximum amplitude of the elastic tine subsoiler is 0.107m, and the maximum amplitude of the rigid subsoiler is 0.026 m.

The power spectral density function is a main statistical parameter of the frequency domain characteristic of the random vibration and can be used for representing the statistical average spectral characteristic of the random vibration. The self-power spectral density function shows the distribution condition of the power at the frequency of the vibration signal grid, so that the power of which frequencies are main is known, and the data file dimension of the self-power spectral density function is the square of the original data file. FIG. 17 shows the amplitude-frequency curve of the vibration acceleration self-power spectrum of the elastic tine subsoiler, and FIG. 18 shows the amplitude-frequency curve of the vibration acceleration self-power spectrum of the rigid subsoiler. The elastic tooth type subsoiler has the maximum value at 5.86Hz and the power spectral density is 0.038 (m/s)²)²The rigid subsoiler exhibits a maximum at 4.39Hz, and a power spectral density of 0.005 (m/s)²)². The random signals are mostly concentrated on the frequency corresponding to the maximum amplitude, the vibration main frequency of the elastic tooth type subsoiler can be considered as 5.86Hz, and the rigid subsoilerThe vibration main frequency is 4.39Hz, which is smaller than that of the spring tooth type subsoiler. The characteristic of the rigid subsoiler shovel handle shows that the rigid subsoiler does not vibrate, the vibration of the rigid subsoiler is caused by the action of soil resistance and the traction action of the soil trough trolley, and the vibration frequency generated by the action of the external environment on the subsoiler is close to 4.39 Hz.

(3) Analysis of vibration process of spring-tooth type subsoiler

Fig. 19 shows the deformation of the elastic teeth during tillage, and analysis in conjunction with fig. 19 shows that as the implement moves forward, during a time period t0-t1, the tooth tips of the elastic teeth type subsoiler move from the point O' to the point a through the point O of the equilibrium, the elastic potential energy of the elastic teeth increases gradually from zero, the elastic force is smaller than the soil resistance, and when the tooth tips move to the point a where the deformation is maximum, namely time t1, the elastic potential energy of the elastic teeth is maximum; at a time period of t1-t2, the elastic teeth rebound and release energy, the soil resistance reaches the yield limit, the soil is loosened, the soil resistance rapidly drops, when the elastic teeth recover to the balance position (point 0), namely time t2, the elastic potential energy of the elastic teeth is zero, and the acting force of the subsoiler on the soil is 0; and in the time period t2-t3, the subsoiler continues to move forwards to compress loose soil, the soil resistance is gradually increased, the spring deforms towards the other direction to store energy, when the point B at the maximum deformation position is reached, the elasticity is maximum, the energy is rapidly released again, the point 0 at the balance point is returned (the time period t3-t 4), and the process is repeated. The cultivation process of the spring-tooth subsoiler can be summarized as follows: the soil resistance is increased, so that the elastic teeth are deformed and accumulated with energy, when the elastic potential energy of the elastic teeth is maximum, the soil yield limit is reached, the energy is rapidly released, and the soil is loosened. Therefore, the continuous change of soil resistance is the main reason of the vibration of the elastic tooth type subsoiler. And the low-frequency components such as uneven ground surface and uneven soil texture lead to continuous change of soil resistance, thereby causing vibration of the elastic tooth type subsoiler.

The test summary is as follows:

(1) as can be seen from the traction resistance one-factor test, the traction resistance increases with the increase of the advancing speed and the tilling depth. When the advancing speed and the working depth are the same, the traction resistance of the elastic tooth type subsoiler is reduced by 9.95 percent compared with that of a rigid subsoiler, the specific subsoiler resistance is reduced by 14.52 percent, and the elastic tooth type subsoiler has better subsoiling and drag reduction effects.

(2) Orthogonal test analysis shows that when a spring-tooth type subsoiler is selected, the advancing speed is 1m/s, and the tilling depth is 20cm, the traction resistance, the power consumption and the subsoiling specific resistance all have minimum values. The elastic tooth type subsoiler has better subsoiling and drag reduction effects than a rigid subsoiler, but the tillage depth is shallow, and the elastic tooth type subsoiler is only suitable for near-surface areas, while the rigid tooth type subsoiler is suitable for soil with the plough bottom layer with the subsurface depth of more than 20 cm.

(3) The vibration main frequency of the elastic tooth type subsoiler is 5.86Hz, and the vibration main frequency of the rigid subsoiler is 4.39 Hz. The low-frequency components such as uneven ground surface and uneven soil texture lead to continuous change of soil resistance, and further vibration of the elastic tooth type subsoiler is caused. The rigid subsoiler does not vibrate itself, and its vibration is caused by the action of the resistance of the soil and the traction of the soil box trolley.

Secondly, finite element analysis of interaction of the deep scarification component and the soil:

in order to analyze the action condition of the vibratory and non-vibratory subsoiling components on the soil more intuitively, a finite element analysis method is adopted in the chapter to simulate the action process of the subsoiler and the soil. When finite element calculation and simulation calculation are applied to simulate the farming process, most researchers define the soil as a continuous viscoelastic body, and the actual soil is a discrete granular object. The SPH method is a typical non-grid Lagrange numerical method, and the research sets soil materials as SPH particles, so that simulation is close to actual conditions, the simulation is more real and reliable, and analysis is more visual.

(1) Process for acting different subsoilers on soil

Fig. 20-25 show the subsoiling of the soil by the rigid subsoiler for 1.7s, 3.5s, 5.2s, 6.8s, 8.4s, 9.4s, respectively, over time.

For the rigid subsoiler, along with the movement of the subsoiler, the shovel head cuts soil, the soil above the chisel-shaped shovel is extruded by the wedge surface and lifted upwards, the soil is tightly attached to the upper surface of the chisel-shaped shovel, the lifting height is basically consistent, at the moment, the soil is sheared in the normal direction of the wedge surface of the subsoiler, and due to the bending of the subsoiler handle, the lifted soil is bent, so that the soil above the wedge surface is sheared, bent and broken gradually. Along with the forward movement of subsoiler, the soil at subsoiler rear portion appears the crack gradually, and the crack grows gradually, moves down under the effect of gravity. So that a gap appears between the soil of the upper layer and the soil of the lower layer separated by the chisel-shaped shovel to form a rat channel. The subsoiler moves over the upper soil layer and moves downwards under the action of gravity, so that the soil compressed by the subsoiler on the upper layer is separated. In the whole process of deep scarification, the soil is loosened due to the downward movement of the soil after the soil is lifted by the chisel-shaped shovel and the soil is lifted, and the purpose of deep scarification is achieved.

FIGS. 26-31 show the subsoiling of the soil by the elastic tooth subsoiler for 1.7s, 3.5s, 5.2s, 6.8s, 8.4s, 9.4s, respectively, over time.

For the elastic-tooth type subsoiler, the soil on the upper part and the lower part of the shovel head is influenced in a certain range under the influence of the loosening range of the double-wing shovel. Because the double-wing shovel type bends downwards, receives the effect of soil adhesion, along with the antedisplacement of subsoiler, the soil of double-wing shovel lower part is the back that adheres at the double-wing shovel earlier, and is lifted up, when lifting to a take the altitude, and the soil of shovel back loses the effect of shovel, receives the influence of gravity, moves downwards again. Because the adhesion of soil is great and receive the influence of shovel type, the partly soil that is close subsoiler bottom receives the ascending effort of subsoiler stronger, and big crack appears in the soil bottom. As the soil-entering angle of the elastic tooth type subsoiler is larger, the longitudinal influence range of soil is larger, and the subsoiling range is larger.

The action process of the subsoiler on the soil can be summarized as a cutting-lifting-soil-breaking process, and the soil-breaking process can be summarized as a lifting-loosening-descending process.

(2) Equivalent stress analysis of subsoiler

Fig. 32-35 show graphs of equivalent stress changes of the rigid subsoiler over time for 2.5s, 5.0s, 7.5s, 9.5 s.

Fig. 36-39 show equivalent stress profiles for the snap subsoiler in the 2.5s, 5.0s, 7.5s, 9.5s over time.

For the rigid subsoiler, the maximum stress of the rigid subsoiler is always at the joint A of the shovel handle and the shovel head. The rigid shovel handle has higher hardness, and the front end of the shovel handle is provided with the pointed bulge, so that the rigid shovel handle has a certain cutting effect on soil, and the stress change is not very large. At the joint A of the shovel handle and the shovel head, the subsoiler has an upward oblique acting force on soil and is under the action of horizontal traction force and soil gravity, and the generated stress is the largest.

For the elastic tooth type subsoiler, the maximum stress of the elastic tooth type subsoiler is generated at a first bending part B of an S-shaped shovel handle, because the S-shaped elastic tooth is small in hardness, the upper part of a shovel head is under the action of soil resistance during subsoiling operation, so that the included angle between the shovel head and a horizontal plane is increased, and the part below a second bending part C of the elastic tooth is deformed and tends to be straightened. Due to the shape characteristic of the double-wing shovel, the contact area with soil is large, the acting force of the S-shaped shovel handle is increased, the main acting point of the S-shaped shovel handle is located at the first bending part B, so that the thickness of the S-shaped shovel handle can be increased properly when the S-shaped elastic tooth is designed, the hardness is increased, the S-shaped elastic tooth is damaged in a small deep loosening process, the thickness is not too large easily, the S-shaped elastic tooth is lost due to too large rigidity, the elastic force of the S-shaped elastic tooth is achieved, and the significance of vibration can be achieved.

(3) Traction resistance time history

Fig. 40 shows the time history of the traction resistance of the rigid subsoiler and fig. 41 shows the time history of the traction resistance of the latch-type subsoiler. The contrast rigidity subsoiler and the drag force curve of bullet tooth-like subsoiler can know, and rigidity subsoiler pulls the drag force and increases rapidly, and has certain undulant, and after whole shovel handle got into soil, the drag force fluctuated at certain extent, did not take place big change. The elastic tooth type subsoiler has the advantages that the traction resistance is stably increased along with the entering of the shovel head and is not fluctuated, and after the whole elastic tooth type subsoiler enters soil, the traction resistance is rapidly reduced, so that the S-shaped shovel handle is deformed under the action of the soil resistance, vibration is generated along with the change of the soil resistance, and the vibration has the effect of resistance reduction, so that the traction resistance is reduced. Therefore, the elastic tooth type subsoiler has the effect of resistance reduction.

(4) Finite element analysis summary of interaction of deep scarification component and soil

1. The LS-DYNA display dynamics analysis program is applied, when the subsoiling operation is carried out, the subsoiler simulates the cutting process of soil, the action process of the subsoiler on the soil is analyzed, the action process of the subsoiler on the soil can be summarized as the cutting-soil lifting-soil crushing process, and the soil crushing process can be summarized as the lifting-loosening-descending process.

2. The equivalent stress distribution of the subsoiler is analyzed, the maximum stress of the rigid subsoiler is always at the connection part of the shovel handle and the shovel head, and the maximum stress of the elastic tooth type is generated at the first bending part of the S-shaped shovel handle. The maximum shear stress, the soil speed and the soil throwing track of the soil in the subsoiling process are analyzed, the soil disturbance range of the elastic tooth type subsoiler is larger, and the loosening effect is more obvious.

3. The time history of the traction resistance in the subsoiling process is analyzed, when the subsoiler enters the soil, the traction resistance of the rigid subsoiler fluctuates within a certain range, the traction resistance of the elastic tooth type subsoiler is rapidly reduced, and the resistance reduction effect is obvious.

Simulation of integral tillage process of layered deep scarification mechanism

And according to the parameter optimization result, obtaining the optimal configuration parameters of the relative positions of the front shovel and the rear shovel of the layered subsoiling mechanism, and simulating the subsoiling process of the layered subsoiling mechanism by applying an LS-DYNA display dynamics analysis program. The forward speed of the machine is 1m/s, the action time is 7s, and the maximum tilling depth is 30 cm.

(1) Process for acting deep scarification mechanism on soil

When the elastic-tooth type subsoiler enters the soil, the soil is circularly diffused outwards along with the forward movement of the subsoiler, the loose soil is uniformly distributed, and gaps appear in the soil around the front shovel head. When the rear shovel rigid subsoiler enters the soil, a transverse crack occurs in the soil below the rigid subsoiler. The effect of the rear shovel is mainly to loosen the soil layer below the shovel head of the rear shovel and enable the soil to have a fault. Thus, the front shovel is provided with two purposes, one is to loosen near-surface soil and the other is to reduce the resistance of the upper soil, so that the resistance of the rear shovel is reduced when loosening deep soil.

After deep scarification, the movement track of the upper layer soil particles is far, the soil disturbance amount is large, and the soil particles have an upward oblique movement trend, namely the soil particles move towards the normal direction of the perpendicular bisector of the shovel head under the action of the shovel head. The soil particles of the soil in the lower layer move obviously slightly, and because the soil has horizontal spaced faults, the soil particles only move in the respective faults and do not have the movement tendency towards the adjacent faults. Although the motion laws of the soil on the upper layer and the lower layer are different, the soil on the upper layer and the soil on the lower layer move in respective soil layers, the upper soil layer and the lower soil layer do not turn over, and the positions of the surface soil layer and the bottom soil layer are not changed, so that the bottom soil layer is thermalized in situ.

(2) Traction resistance time history

FIG. 42 shows a time history of the traction resistance of the layered subsoiling mechanism, compared to a comparative example of the soil treatment process by the subsoiling mechanism. The time period of 0.5S-2S is the time period when the front shovel head enters, so the traction resistance is steadily increased and gradually stabilized, the time period of 3S-4S is the time period when the handle of the front shovel enters the soil, the traction resistance is increased, after the whole front shovel enters the soil, the traction resistance soil is decreased, due to the elastic vibration of the S-shaped handle of the front shovel, the traction resistance is reduced, and when the time period of 4.5S is the time period when the rear shovel enters the soil, the traction resistance is increased in a small range and fluctuates to some extent, but the traction resistance is not obviously increased. From the above analysis, it is clear that the arrangement of the front shovel elastic tooth subsoiler does serve the purpose of reducing the traction resistance, while the arrangement of the rear shovel rigid subsoiler is intended to loosen the harder soil deeper. Therefore, the design of the layered deep scarification mechanism not only meets the requirement of deep ploughing, but also reduces the traction resistance, reduces the energy consumption and saves the energy.

Analysis of test results of layered subsoiling mechanism

(1) Working stability of layered deep scarification mechanism and analysis of surface condition after deep scarification

In the test process, the deep scarification machine has no blockage and has good passing performance. When the subsoiler works, the subsoiler reciprocates for two strokes, and the soil penetration stroke of the subsoiler is measured once in each stroke, namely the horizontal advancing distance of the subsoiler from soil penetration to stable soil loosening depth is measured. The measurement results are shown in tables 6-4, and the average value of the soil-entering travel of the subsoiler is calculated to be 2.2m or less and 2.5m, so that the soil-entering travel meets the quality standard of the subsoiler. When the subsoiling part enters the soil, the whole machine slightly vibrates, when the subsoiler completely enters the soil, the subsoiler works stably, the work of the subsoiler is more stable and is perpendicular to the advancing direction, and the large vibration phenomenon does not occur.

TABLE 6-4 deep scarification and penetration travel measurement statistical table

Tab.6-4Statistical table of measurement of subsoiling under soildistance

(2) Analysis of soil loosening furrow shape

And drawing a soil profile of the loose soil ditch, as shown in the figure. The average area of the soil section after deep scarification is 620.6cm 2. As can be seen from the figure, the soil profile after subsoiling is basically isosceles trapezoid, but the inverted trapezoid can still be obviously seen to be divided into two areas, because the subsoiler is provided with a front subsoiler handle and a rear subsoiler handle, the lower narrow groove is dug out by a chisel type shovel equipped with a rigid subsoiler, the farming depth is 30cm, the lower groove width is 10cm, the larger inverted trapezoid at the upper part is dug out by a double-wing shovel equipped with a snap-tooth type subsoiler at the front part of the subsoiler, the farming depth is 20cm, and the upper groove width is 30 cm. The arrangement of the front shovel and the rear shovel of the subsoiler enables soil after subsoiling to form a layered structure, enlarges the soil loosening range of the subsoiler, and improves the water storage and moisture conservation capacity of the soil.

In summary, the layered subsoiling mechanism provided by the application comprises an elastic tooth type subsoiling shovel and a rigid subsoiling shovel, can perform layered subsoiling on soil, and utilizes the elastic tooth type subsoiling shovel to loosen the upper soil layer and the rigid subsoiling shovel to loosen the lower soil layer; after the soil is layered and deeply loosened, the plough bottom layer structure is damaged, the state that the soil is compacted is changed, the permeability of the soil is improved, and a large amount of rainwater permeates; after the soil is layered and deeply loosened, the soil layer can be kept to be not disordered, the soil is properly scattered after ploughing, and the condition that soil blocks are emptied in the plough layer at the deeply loosened part can be avoided; due to the characteristics of layered deep scarification, the shallow soil and the deep soil are respectively operated by different subsoilers, so that the upper soil layer and the lower soil layer of the deeply scarified soil are not turned, a soil structure with a virtual upper part and a real lower part is formed, the positions of the surface soil and the bottom soil are not changed, and the bottom soil is thermalized in situ; the groove formed after the deep loosening can well store water and reduce evaporation, and has the functions of resisting drought, reducing disasters and keeping water and soil.

The above disclosure is only for a few specific embodiments of the present invention, however, the present invention is not limited to the above embodiments, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present invention.

Claims

1. A layered deep loosening mechanism is characterized by comprising an elastic tooth type deep loosening piece for loosening upper soil, wherein a rigid deep loosening piece for loosening lower soil is arranged behind the elastic tooth type deep loosening piece along the deep loosening direction; the elastic tooth type deep loosening piece comprises a double-wing shovel (9) and an elastic shovel handle (10), the double-wing shovel (9) is fixed at the lower end of the elastic shovel handle (10), and the elastic shovel handle (10) is an S-shaped elastic tooth type deep loosening shovel handle; the rigid deep scarification part comprises a rigid shovel head (11) and a rigid shovel handle (12), and the rigid shovel head (11) is fixed at the lower end of the rigid shovel handle (12); the shovel tip of the double-wing shovel (9) is positioned above the shovel tip of the rigid shovel head (11); the elastic shovel handle (10) is connected with the rigid shovel handle (12) into a whole through a connecting piece (13).

2. A layered deep scarification mechanism according to claim 1, characterised in that the thickness of the S-shaped first bend of the resilient blade handle (10) is greater than elsewhere.

3. A layered deep scarification mechanism according to claim 1, characterised in that the connection (13) is a horizontal connecting rod; the elastic shovel handle (10) is fixed at one end of the connecting rod, and the other end of the connecting rod is detachably connected with the rigid shovel handle (12); the connecting rod is transversely provided with a plurality of first through holes for adjusting the front-back distance between the rigid shovel handle (12) and the elastic shovel handle (10), the rigid shovel handle (12) is longitudinally provided with a plurality of second through holes for matching with the first through holes, and the second through holes with different heights are matched with the first through holes for adjusting the difference of the upper and lower tilling depths.

4. A layered subsoiling mechanism as claimed in claim 1, characterized in that said rigid blade head (11) is a standard chisel type blade and the rigid blade handle (12) is a standard post type subsoiler handle.

5. A layered deep scarification mechanism according to claim 1, characterised in that the double-wing shovel (9) is a triangular double-wing shovel.

6. A layered deep scarification mechanism according to claim 3, characterized in that the upper end of the elastic shovel handle (10) is fixedly connected with the block body (14), and the lower end of the elastic shovel handle (10) is fixedly connected with one end of the double-wing shovel (9) far away from the shovel tip; the block body (14) is fixed at one end of the connecting piece (13), and the other end of the connecting piece (13) is detachably connected with the rigid shovel handle (12).

7. A layered deep scarification mechanism according to claim 3, wherein the detachable connection is a bolt connection, and a bolt passes through any one second through hole formed on the rigid shovel shaft (4) and any one first through hole formed on the connecting rod in sequence and is in threaded connection with a nut.

8. A deep scarification method of a layered deep scarification mechanism is characterized by comprising the following steps: