Combined furrow opener with a throw-out piece and method for designing a throw-out piece

Abstract

The utility model relates to a combined furrow opener with a throwing blade and a design method of the throwing blade, and belongs to the technical field of furrow openers. The combined furrow opener with a throwing blade comprises an arc-shaped soil cutting blade and a throwing blade arranged on the soil cutting blade, the throwing blade is an arc-shaped curved blade, is arranged on the inner arc side of the soil cutting blade, the working end of the throwing blade is close to the tangent blade of the soil cutting blade, the distance L between the center of mass of the throwing blade and the angle top end of the tangent blade of the soil cutting blade is 50, a curved shape is formed towards the tangent blade end and the inner side of the soil cutting blade, the curved angle alpha of the throwing blade obtained according to the design method of the utility model is 30 DEG, and the maximum width b of the throwing blade is 60mm. When the combined furrow opener is installed on a furrow opener disc to carry out furrowing, the overall furrowing width can be guaranteed to be less than or equal to 100mm, and efficient furrowing can be guaranteed while reducing soil disturbance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of agricultural machinery, and particularly relates to a combined furrow opener with a soil throwing piece and a design method of the soil throwing piece. BACKGROUND

[0002] The traditional fertilizer furrow opener has a large furrowing width. Although the large furrowing width can increase the contact area of the fertilizer, the soil is disturbed more. In the operation process, the overwide furrow causes damage to the growth of the fruit trees and also causes damage to the soil structure, thereby affecting the air permeability and water retention of the soil. Moreover, the existing furrow opener does not combine the advantages of the soil cutting blade and the soil throwing piece, and in the operation process, the furrow opener causes great damage to the root system of the fruit trees and cannot be adjusted according to the distribution of the root system of the fruit trees, so that the root system of the fruit trees is easily cut off in the furrowing process, thereby seriously affecting the healthy growth of the fruit trees. SUMMARY

[0003] In view of the above technical problems, the present application provides a combined furrow opener and a design method thereof, and aims to improve the suitability of the furrowing width and reduce the damage to the fruit trees and the soil.

[0004] The object of the present application is achieved by the following technical solutions.

[0005] The combined furrow opener with a soil throwing piece comprises an arc-shaped soil cutting blade and a soil throwing piece arranged on the soil cutting blade, the soil throwing piece is an arc-shaped curved blade, is arranged on the inner arc side of the soil cutting blade, the working end of the soil throwing piece is close to the tangent blade of the soil cutting blade, the distance L between the center of mass of the soil throwing piece and the top end of the tangent blade of the soil cutting blade is 50, a curved shape is formed towards the tangent blade end and the inner side of the soil cutting blade, and the bending angle a is 30°.

[0006] Further, the soil cutting blade is an arc-shaped blade with a curved surface bent to one side at the end, the end bending part is a tangent part, a side cutting part is connected to the tangent part in transition, a root part is a blade handle, the outer side of the side cutting part and the tangent part forms an outer side side cutting blade, the outer side side cutting blade is an arc-shaped structure with an end part bent to the curved surface, the end part of the tangent part is a tangent blade in an angular structure, and the tangent surface of the tangent blade close to the end part of the outer side side cutting blade is a tangent surface; the curved surfaces of the soil cutting blades installed on the two sides of the furrow opener disc face away from each other, i.e., the curved surfaces face outward.

[0007] Further, the height H of the tangent surface of the tangent blade is 65mm.

[0008] Further, the width of the two ends of the soil throwing piece is smaller than the width of the middle part, the maximum length W of the soil throwing piece is 120mm, and the maximum width b is 60mm.

[0009] The design method of the soil throwing piece of the combined furrow opener is as follows.

[0010] The parameters that affect the distance of soil throwing are determined as follows: trenching depth, bending angle α of soil throwing piece and maximum width b of soil throwing piece;

[0011] The trenching depth is the same as the height H of the cutting edge of the soil throwing piece, which is set to 65 mm;

[0012] The bending angle α of the throwing piece is the relative bending angle from the soil entry point to the throwing point, that is, the bending shape of the throwing piece; so that the soil is gradually guided from the inner arc side of the throwing piece to the throwing direction;

[0013] The maximum width b of the throwing blade determines the lateral distribution of the soil on the throwing blade. The soil is evenly distributed on the surface of the throwing blade during the throwing process. The maximum width b of the throwing blade ensures that the soil can quickly break away from the throwing blade during the throwing process and achieve the maximum throwing distance.

[0014] Considering the soil particles as point masses, the soil moves in a parabolic motion when leaving the throwing piece. The distance the soil flies out of the throwing piece is:

[0015]

[0016] S=Bsinδ1 (3)

[0017] Where, B—soil throwing distance, m

[0018] S—lateral soil throwing distance, m

[0019] v—initial velocity when thrown, m / s

[0020] δ—Angle between the initial velocity and the ground when thrown, (°)

[0021] δ1—projection of initial velocity v on the ground and v y Angle, (°)

[0022] g—acceleration due to gravity, 9.8m 2 / s

[0023] v x 、v y 、v z —The component of the initial (absolute) velocity v in the three-dimensional rectangular coordinate system of space, m / s

[0024] And δ1 satisfies tanδ1=v y / v x

[0025] Substituting formula (2) into formula (1) yields:

[0026]

[0027] The maximum width b of the throwing piece and the tilt angle γ of the throwing piece will affect v x、v y 、v z ,

[0028] Establish the coordinate system oxyz, where point o is the center of rotation of the thrower, the positive direction of the y-axis is consistent with the forward direction of the machine, the x-axis is horizontal, the z-axis is vertical, and the front of the thrower handle is in the yoz plane;

[0029] Then, take the intersection of the long and short sides of the cast-off piece as the coordinate origin o1, the short side as the x1 axis, and the long side as the y1 axis, and establish the coordinate system x1o1y1 on the cast-off piece plane. The x1o1y1 plane forms an angle γ with the yoz plane, which is the inclination angle of the cast-off piece, and the x1o1y1 plane forms an angle β with the xoy plane.

[0030] According to the angle relationship between the soil throwing piece and the soil cutting knife rotation center coordinate system yoz, xoy, v x 、v y 、v z Expressed as:

[0031]

[0032] Where:

[0033] r1—the radius of gyration of the intersection o1 of the long side and short side of the soil throwing piece near the end of the soil cutting knife, in m; the long side is on the y1 axis and the short side is on the x1 axis;

[0034] v r —Relative speed of soil sliding on the surface of the dumping piece, m / s

[0035] ω—grooving knife rotational angular velocity, rad / s

[0036] v m —Soil speed along with trencher, m / s

[0037] v a —Soil entrainment speed of the combined trenching blade 12, m / s

[0038] v x 、v y 、v z is the component of the absolute velocity v in the three-dimensional rectangular coordinate system of space. The absolute velocity v of the soil on the throwing piece 13 is the involved velocity v driven by the rotation of the throwing and cutting combined trenching knife 12. a , the relative speed v of soil sliding on the surface of the soil throwing piece 13 r , soil moves along with the trencher's forward speed v m The vector sum of , v r 、v a 、v m The velocity components are v in the three-dimensional rectangular coordinate system of space. xv y ,v z , separately solved and vector-summed to obtain the absolute velocity v of the soil to determine its trajectory of projection;

[0039] where the direction of the velocity v a is negative in the y-axis, and the calculation formula is:

[0040]

[0041] where x'1 is the instantaneous horizontal coordinate of the soil particle on the soil-throwing piece 13,

[0042] δ2 is the angle between r1 and the y-axis, (°)

[0043] Under the action of the soil-throwing knife, the soil is subjected to the combined action of gravity, centrifugal force, Coriolis force and friction, wherein the components of gravity on the x1 and y1 axes G x , G y are both mgsinγcosβ; the components of centrifugal force on the x1 and y1 axes F lx , F ly are calculated as:

[0044]

[0045] Let k = cosβcosγ, the components of Coriolis force on the x1 and y1 axes F gx , F gy are:

[0046]

[0047] Let k1 = ω 2 (r1cosδ2-x'1cosβ), the components of friction on the x1 and y1 axes F fx , F fy are:

[0048] F Gx = mfsinρ(sinβ(gsinγ+k1)+2v C ω(cosρsinγ+sinρ)cosβ) (9)

[0049] where ρ is the angle between the relative velocity of the soil and the x1 axis, (°)

[0050] F is the friction factor between the soil particle and the surface of the soil-throwing piece

[0051] According to the geometric relationship, the direction of the relative velocity v r satisfies:

[0052]

[0053] When the soil slides from the side cutting part and tangential part of the combined trenching cutter to the y1 axis of the soil throwing piece, the relative speed v r The direction coincides with the x1 axis, so the angle ρ is 0°, and at this time the soil is only affected by gravity and centrifugal force, then formula (9) is derived as:

[0054] g=-ωcosβ(r1cosδ2+x′1cosβ)tanγ (11)

[0055] According to the trenching depth, the end face height H of the combined trenching cutter is set to 65mm, the curves of the tangential and side cutting edges remain unchanged, and the turning radius r1 of point o1 is set to 230mm. Then, the turning radius angle δ2 of point o1 is set to 60°, so that the tool can ensure the motion trajectory and throwing effect of the soil throwing piece during the rotation process;

[0056] The material of the soil throwing piece is manganese steel, and the friction coefficient f between it and the soil is 0.65. When the soil slides in contact with the soil throwing piece, the sliding speed and movement direction of the soil are guaranteed;

[0057] Since the tangent part of the throwing piece and the throwing and cutting combined trenching knife is also inclined along the bending line MK, and the inclination angle is consistent with the bending angle α of the tangent part, the angle β formed by the coordinate system x1o1y1 plane established on the throwing piece plane and the xoy plane is consistent with the bending angle α of the throwing and cutting combined trenching knife, both of which are 30°, that is,

[0058] β=α=30°;

[0059] Set the forward speed v of the machine with the combined trenching blade installed m is 0.5m / s; the shaft speed of the furrowing cutter is 200r / min, so ω is 20.94rad / s; according to the agronomic requirement of throwing soil to the furrow edge with a maximum width of 100mm, the width of the soil throwing, that is, the horizontal distance of the soil throwing S is taken as 100mm, and the unknowns γ, b, and v are solved by the above formulas (3), (8), and (9): r , use elimination method to eliminate v r Finally, we get γ = 30°, x'1 = 60 mm, and the maximum width b of the soil throwing piece is equal to the instantaneous horizontal coordinate x'1 of the soil particles on the soil throwing piece, that is, b = 60 mm;

[0060] Where γ is the angle formed by the x1o1y1 plane and the yoz plane;

[0061] β is the angle between the x1o1y1 plane and the xoy plane.

[0062] The beneficial effects of the present invention are:

[0063] 1. The combined trenching knife of the present invention consists of an arc-shaped soil cutting knife and a soil throwing piece provided thereon. The soil throwing piece is an arc-shaped curved blade provided on the inner arc side of the soil cutting knife. The working end of the soil throwing piece is close to the positive cutting edge of the soil cutting knife. The distance L between the center of mass of the soil throwing piece and the top of the positive cutting edge angle of the soil cutting knife is 50 mm, forming a curved shape toward the positive cutting edge end and the inner side of the soil cutting piece. The bending angle α is 30°, which optimizes the trenching width design, ensures that the overall trenching width is less than or equal to 100 mm, and can ensure efficient trenching while reducing soil disturbance.

[0064] 2. In order to ensure that the soil can be efficiently ejected, the present invention uses a combination of trenching knives and soil-throwing blades that are alternately installed on the trenching cutter disc. The speed range of the trenching cutter disc is adjusted within 0.4m / s-1m / s, and the speed range of the cutter shaft is between 133.76rad / min-286.62rad / min. It can flexibly respond to different soil conditions and adjust the appropriate speed to adapt to the hardness and moisture of the soil. When a lower speed is selected, it helps to reduce disturbance to the soil structure while ensuring sufficient power to complete soil cutting and movement, which is very suitable for areas where the roots of fruit trees are sensitive. When a higher speed is selected, the soil can be thrown farther and distributed more evenly, which is also conducive to cutting off crop residues in the soil.

[0065] 3. The optimized layout of the combined trenching blades of the present invention results in less overall disturbance of the soil by the machine during operation, especially in orchards where it is necessary to protect the soil organic structure and avoid damaging the root system. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a structural schematic diagram of the present invention.

[0067] Figure 2 It is a side structural schematic diagram of the present invention.

[0068] Figure 3 for Figure 2 Schematic diagram of the position relationship between the middle throwing soil piece and the cutting knife.

[0069] Figure 4 It is a schematic structural diagram of the soil cutting knife in the present invention.

[0070] Figure 5 Schematic diagram of the earth throwing piece structure.

[0071] Figure 6 for Figure 5 Schematic diagram of the three-dimensional structure.

[0072] Figure 7 、 Figure 8 This is the principle diagram for analyzing the soil throwing process of the combined throwing and cutting trenching knife.

[0073] Figure 9 This is a schematic diagram of the structure of the present invention installed on a trenching cutter disc.

[0074] Figure 10 for Figure 9 Left view of .

[0075] In the figure: 1. Combined trenching knife, 11. Soil cutting knife, 111. Cutting edge, 112. Tangent portion, 113. Side cutting edge, 114. Knife handle, 115. Side cutting portion, 116. Tangent end face, 12. Soil throwing piece; 2. Trenching cutter disc. DETAILED DESCRIPTION

[0076] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0077] Example: Figures 1-8 As shown, the combined trenching knife 1 with a soil-throwing blade includes an arc-shaped soil-cutting knife 11 and a soil-throwing blade 12 arranged thereon. The soil-throwing blade 12 is an arc-shaped curved blade, which is arranged on the inner arc side of the soil-cutting knife 11. The working end of the soil-throwing blade 12 is close to the positive cutting edge of the soil-cutting knife 11. The distance L between the center of mass of the soil-throwing blade 12 and the top of the positive cutting edge angle of the soil-cutting knife 11 is 50, forming a curved shape toward the positive cutting edge end and the inner side of the soil-cutting blade 11. The bending angle α is 30°, that is: α is the inclination angle of the line from the top of the soil-throwing blade to the root of the curve relative to the intersection surface of the side cutting portion and the tangential portion of the soil-cutting knife.

[0078] like Figure 3-Figure 4 As shown, the soil cutter 11 is an arc-shaped blade with a curved surface at one end. The curved portion at the end is a tangent portion 112, which is connected to a side cutting portion 115. The root is a blade handle 114 with a mounting hole. The side cutting portion 115 and the tangent portion 112 form an outer side cutting edge 113 on the outside. The outer side cutting edge 113 is an arc-shaped structure with an end that curves toward the curved surface 112. The end of the tangent portion 112 is a tangent blade 111 with an angular structure to facilitate cutting into the soil. Near the end of the outer side cutting edge 113 is a tangent surface of the tangent blade 111. The tangent surface end surface 116 has a height H of 65 mm and a sharp edge, which is used to effectively cut and crush the soil. The soil cutters 11 mounted on both sides of the trenching cutter disc 2 of the present invention have opposite curved surfaces, that is, the curved surfaces face outward. The height H of the tangent surface of the tangent blade is 65 mm.

[0079] like Figure 5 、 Figure 6 As shown, the width of the two ends of the soil-throwing piece 12 is smaller than the width in the middle. The maximum length W of the soil-throwing piece 12 is 120 mm, the maximum width b is 60 mm, and the thickness h is 6 mm, which can ensure a trenching of 100 mm. When the combined trenching knife is installed, the soil-throwing piece is located on the cutting knife facing the rotation direction of the trenching cutter disc.

[0080] Analysis of the soil throwing process of the combined trenching knife 12, such as Figure 7 、 Figure 8 As shown, the design method of the soil throwing piece is as follows:

[0081] The parameters that affect the distance of soil throwing are determined as follows: trenching depth, bending angle α of soil throwing piece and maximum width b of soil throwing piece;

[0082] The trenching depth determines the depth to which the soil is cut and thrown; it is related to the working depth of the trenching knife, the thickness of the cut soil, and the movement path of the soil on the throwing blade. The depth of cutting into the soil affects the movement trajectory of the soil during throwing; when the trenching depth is greater, the kinetic energy of the soil will be greater, so the distance it is thrown will also increase. The trenching depth is the same as the height H of the positive cutting edge of the throwing blade. This height is the path that the soil passes through during the cutting and throwing process; the trenching depth determines the contact area and friction between the soil and the throwing blade, and also affects the relative speed of the soil before throwing; therefore, a larger trenching depth can increase the throwing distance, but if the depth is too large, it may cause too much soil to be thrown, thereby affecting the overall throwing effect of the soil. In this example, the trenching depth and the height H of the positive cutting edge of the throwing blade are both set to 65mm;

[0083] The bending angle α of the throwing blade determines the direction in which the soil is thrown. In the design of the throwing blade, the bending angle affects the trajectory of the soil flying off the throwing blade and the initial angle of the soil. The bending angle α of the throwing blade is the relative bending angle between the soil entry point and the throwing point, that is, the bending shape of the throwing blade. This gradually guides the soil from the inner arc side to the throwing direction, so that it has a certain throwing angle when it leaves the throwing blade. According to the throwing theory, the horizontal movement distance B of the projectile is related to the throwing angle α, and the maximum throwing distance usually occurs at an angle of about 45 degrees. In actual application, the bending angle α is adjusted according to the specific working conditions to maintain the optimal throwing effect under different soil conditions, which can both ensure sufficient throwing distance and reduce soil disturbance.

[0084] The maximum width b of the throwing blade directly affects the contact area between the soil and the throwing blade, which in turn affects the blade's ability to grab and throw the soil. This ensures that the soil is evenly distributed on the surface of the throwing blade during the throwing process, increasing the stability of the throwing. The width of the throwing blade determines the lateral distribution of the soil on the throwing blade. A larger width can capture more soil, increase the soil's initial kinetic energy, and thus increase the throwing distance. However, if the width is too large, the soil may not be able to leave the throwing blade smoothly, causing soil retention. Therefore, the width b of the throwing blade ensures that the soil can quickly break away from the throwing blade during the throwing process, achieving the maximum throwing distance.

[0085] The specific algorithm is: consider the soil particles as point masses, and the soil moves in a parabolic motion when leaving the throwing piece. The distance of the soil flying out of the throwing piece is:

[0086]

[0087] S=Bsinδ1 (3)

[0088] Where, B—soil throwing distance, m

[0089] S—lateral soil throwing distance, m

[0090] v—initial velocity when thrown, m / s

[0091] δ—Angle between the initial velocity and the ground when thrown, (°)

[0092] δ1—projection of initial velocity v on the ground and v y Angle, (°)

[0093] g—acceleration due to gravity, 9.8m 2 / s

[0094] v x 、v y 、v z —The component of the initial (absolute) velocity v in the three-dimensional rectangular coordinate system of space, m / s

[0095] And δ1 satisfies tanδ1=v y / v x

[0096] Substituting formula (2) into formula (1) yields:

[0097]

[0098] The maximum width b of the throwing piece and the tilt angle γ of the throwing piece will affect v x 、v y 、v z In order to find the maximum width b and the inclination angle γ of the thrown soil, it is necessary to conduct a dynamic analysis of the thrown soil, such as Figure 7 、 Figure 8 As shown,

[0099] First, establish the coordinate system oxyz, where point o is the rotation center of the cutter, the positive direction of the y-axis is consistent with the forward direction of the machine, the x-axis is horizontal, the z-axis is vertical, and the cutter handle surface on the cutter blade side is located in the yoz plane;

[0100] Since the desired inclination angle γ and the maximum width b of the spoil sheet are both related to the spoil sheet plane, in order to conveniently represent the spoil sheet related parameters, the intersection of the long and short sides of the spoil sheet is taken as the coordinate origin o1, the short side is the x1 axis, and the long side is the y1 axis. A coordinate system x1o1y1 is established on the spoil sheet plane. The x1o1y1 plane forms an angle γ with the yoz plane, and the x1o1y1 plane forms an angle β with the xoy plane.

[0101] According to the included angle relationship between the yoz and xoy coordinate systems of the rotation center of the soil throwing piece and the soil cutting knife, v x y z is expressed as:

[0102]

[0103] In the formula:

[0104] r1 is the rotation radius of the intersection point o1 of the long side and the short side of the soil throwing piece close to the end of the soil cutting knife, m; wherein the long side is on the y1 axis and the short side is on the x1 axis;

[0105] v r is the relative speed of soil sliding on the surface of the soil throwing piece, m / s

[0106] ω is the rotation angular velocity of the soil cutting knife, rad / s

[0107] v m is the forward speed of the soil with the ditcher, m / s

[0108] v a is the entrainment speed of the soil driven by the rotation of the soil throwing and cutting combined soil cutting knife 12, m / s

[0109] v x v y v z is the component of the absolute speed v in the space three-dimensional rectangular coordinate system, and the absolute speed v of the soil on the soil throwing piece 13 is the vector sum of the entrainment speed v a of the soil driven by the rotation of the soil throwing and cutting combined soil cutting knife 12, the relative speed v r of the soil sliding on the surface of the soil throwing piece 13, and the forward speed v m of the soil with the ditcher r v a v m The speed components in the space three-dimensional rectangular coordinate system are v x , v y , and v z , respectively. After being solved individually, the vector sum is obtained to determine the absolute speed v of the soil, so as to determine the trajectory of the soil throwing. The vector sum not only determines the total speed of the soil, but also determines the direction of the soil throwing. Different speed components will affect the soil in different directions, and the vector sum can clearly determine the final throwing angle and distance of the soil; the size and direction of the absolute speed will directly affect the trajectory and distance of the soil throwing;

[0110] The direction of the entrainment speed v a is the negative direction of the y axis, and the calculation formula is:

[0111] ​​

[0112] Where: x'1—the instantaneous horizontal coordinate of the soil particle on the soil throwing piece 13,

[0113] δ2—Angle between r1 and y axis, (°)

[0114] To solve the relative velocity v of soil sliding on the surface of the throwing piece r , the forces acting on soil particles on the throwing piece are analyzed, such as Figure 7 、 Figure 8 As shown in the figure, the soil is subjected to the combined effects of gravity, centrifugal force, Coriolis force and friction under the rotation of the thrower. Among them, the component of gravity on the x1 axis and y1 axis is G x , G y are mgsinγcosβ; the components of the centrifugal force on the x1 and y1 axes are F lx 、F ly The calculation formula is:

[0115]

[0116] Let k = cosβcosγ, the components of the Coriolis force on the x1 and y1 axes are F gx 、F gy for:

[0117]

[0118] Let k1 = ω 2 (r1cosδ2-x'1cosβ), the component of friction force F on the x1 and y1 axes fx 、F fy for:

[0119] F Gx =mfsinρ(sinβ(gsinγ+k1)+2v C ω(cosρsinγ+sinρ)cosβ) (9)

[0120] Where ρ is the angle between the soil relative velocity and the x1 axis (°)

[0121] F—Friction factor between soil particles and the surface of the throwing piece

[0122] According to the geometric relationship, the relative velocity v r Direction meets:

[0123]

[0124] When the soil slides from the side cutting part 115 and the tangential part 112 of the combined trenching blade 12 to the y1 axis of the soil throwing piece, the relative speed v r The direction coincides with the x1 axis, so the angle ρ is 0°, and at this time the soil is only affected by gravity and centrifugal force, then formula (9) is derived as:

[0125] g=-ωcosβ(r1cosδ2+x′1cosβ)tanγ (11)

[0126] According to the trenching depth, the end face height H of the combined trenching cutter is set to 65mm, the curves of the front cutting edge and the side cutting edge remain unchanged, and the turning radius r1 of point o1 is set to 230mm. Then, the turning radius angle δ2 of point o1 is set to 60°. This is to ensure the stability of the motion trajectory of the soil throwing piece and the soil throwing effect during the rotation of the tool, and to ensure that the tool can smoothly complete the functions of cutting and throwing soil during rotation.

[0127] Among them, the trenching depth is based on the cutting mechanics theory. The cutting depth of the trenching knife should meet the balance between soil resistance and cutting force to ensure that the tool can effectively cut into the soil without excessively increasing the cutting resistance. A tangent plane height of 65mm can keep the cutting angle of the trenching knife within the optimal range, thereby reducing the cutting force and improving the working efficiency of the tool; too large a height will increase the cutting angle, resulting in excessive soil resistance; too small a height may lead to insufficient cutting depth, affecting work efficiency; at the same time, it can ensure the appropriate block size of the soil after cutting, avoiding damage to the soil structure and crop roots; it can maintain a stable trenching depth and soil throwing effect in most farmland soils; according to soil disturbance theory, a reasonable trenching knife design not only needs to cut the soil, but also needs to minimize soil disturbance to maintain the soil's air permeability and water retention function; a tangent plane height of 65mm can minimize soil disturbance during trenching, allowing the soil to maintain structural integrity;

[0128] In this example, the throwing blade 13 is made of manganese steel, and the soil is mostly sandy loam. The friction coefficient f between the throwing blade and the soil is 0.65. The friction coefficient f describes the friction between the throwing blade and the soil. Friction plays an important role in the entire throwing process, especially when the soil and the throwing blade are in contact and sliding contact. Friction affects the sliding speed and movement direction of the soil.

[0129] Since the soil-throwing piece 13 and the tangent portion 112 of the combined throwing and cutting trenching blade 12 are also inclined along the bending line MK, and the inclination angle is consistent with the bending angle α of the tangent portion 112, therefore, the angle β formed by the x1o1y1 plane and the xoy plane of the coordinate system established on the plane of the soil-throwing piece 13 is consistent with the bending angle α of the combined throwing and cutting trenching blade 12, both of which are 30°, that is, β=α=30°;

[0130] Set the forward speed v of the machine with the combined trenching blade installed mis 0.5m / s; the shaft speed of the furrowing cutter is 200r / min, so ω is 20.94rad / s; according to the agronomic requirement of throwing soil to the furrow edge with a maximum width of 100mm, the width of the soil throwing, that is, the horizontal distance of the soil throwing S is taken as 100mm, and the unknowns γ, b, and v are solved by the above formulas (3), (8), and (9): r , use elimination method to eliminate v r Finally, we get γ = 30°, x'1 = 60 mm, and the maximum width b of the soil throwing piece is equal to the instantaneous horizontal coordinate x'1 of the soil particles on the soil throwing piece 13, that is, the maximum width b of the soil throwing piece is 60 mm;

[0131] Where γ is the angle formed by the x1o1y1 plane and the yoz plane;

[0132] β is the angle between the x1o1y1 plane and the xoy plane.

[0133] γ=β=α=30°, the bending angle α of the soil throwing blade indicates the degree of bending of the soil throwing blade from the root to the top, which determines the direction of soil throwing; the angle β is the angle between the plane of the soil throwing blade and the rotation plane of the trenching knife; when β=30°, it means that the plane of the soil throwing blade is inclined 30° relative to the rotation plane of the trenching knife, so that the soil throwing blade can effectively throw the soil sideways instead of straightly; the angle γ is the angle formed by the soil throwing blade and the soil cutting knife, which reflects the angle between the soil throwing blade and the soil movement trajectory during the soil throwing process; γ=30°, which means that the angle of the soil when it is thrown from the soil throwing blade is consistent with the relative movement direction of the soil throwing blade. The equality of the three angles ensures the coordinated design of the angles of the soil throwing blade, the soil cutting knife and the soil throwing, which helps to optimize the soil throwing trajectory and distance; and ensures a balance between soil throwing efficiency and reducing soil disturbance.

[0134] When the present invention is used, Figure 9 、 Figure 10 As shown, multiple groups of soil cutting knives 11 are evenly spaced along the circumference of the trenching cutter disc 2, and a group of combined trenching knives 1 is provided between two adjacent groups of soil cutting knives 11. There are two soil cutting knives 11 and two combined trenching knives 1 in each group, which are respectively placed on both sides of the trenching cutter disc 1, and the adjacent soil cutting knives 11 and combined trenching knives 1 on the circumference of the trenching cutter disc 2 are at the same intervals, and are staggered on both sides of the trenching disc 2; soil cutting knives 11 and combined trenching knives 1 are respectively provided on the discs on both sides of the trenching disc 2 at intervals of 180 degrees.

[0135] The radius of the trenching disc 2 is 800mm, and the soil cutters 11 and combined trenching blades 12 on both sides of the trenching disc 2 have a radius of 300mm. The thickness of the trenching disc 2 is 50mm, which can achieve a trenching width of 100mm. The trenching depth can be adjusted to 500mm.

[0136] When the trenching cutter of the present invention is installed on the machine for operation, the speed range of the forward speed of the machine is adjusted within the range of 0.4m / s-1m / s, and the rotation speed range of the trenching cutter disc 2 is between 133.76rad / min-286.62rad / min. When adjusting the forward speed and the cutter disc rotation speed of the trenching machine, it is first necessary to determine the appropriate setting according to the soil type. For example, for heavy clay soils, it is generally recommended to set the forward speed to a lower range, such as 0.4m / s to 0.6m / s, to ensure sufficient digging force, while increasing the cutter disc rotation speed to about 250rad / min to 286.62rad / min to enhance the cutting effect and reduce the burden on the machine. For situations where the trenching depth is deeper, a slower forward speed (about 0.4m / s to 0.5m / s) helps to ensure the accuracy and depth of excavation, while the cutter disc rotation speed can be set in a medium to high range (about 200rad / min to 286.62rad / min) to adapt to the cutting needs of deep soil.

[0137] The components not described in detail in this application are all existing conventional technologies and will not be described in detail here.

[0138] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the scope of protection of the present invention.

Claims

1. A combined trenching cutter with a soil throwing blade, characterized by: The invention comprises an arc-shaped soil cutting knife and a soil throwing piece provided thereon, wherein the soil throwing piece is an arc-shaped curved blade provided on the inner arc side of the soil cutting knife, the working end of the soil throwing piece is close to the positive cutting edge of the soil cutting knife, the distance L between the center of mass of the soil throwing piece and the top of the positive cutting edge angle of the soil cutting knife is 50, and the soil throwing piece is curved toward the positive cutting edge end and the inner side of the soil cutting piece, and the bending angle α is 30°; The soil cutter is an arc-shaped knife with a curved surface bent to one side at the end, the curved portion at the end is a tangent portion, the side cutting portion is transitionally connected to the tangent portion, the root portion is a knife handle, the side cutting portion and the outer side of the tangent portion form an outer side cutting edge, the outer side cutting edge is an arc-shaped structure with an end portion bent toward the curved surface, the end of the tangent portion is a straight cutting edge, which is an angular structure, and the tangent surface of the straight cutting edge is close to the end of the outer side cutting edge; the curved surfaces of the soil cutters installed on both sides of the trenching cutter disc are opposite to each other, that is, the curved surfaces face outwards; The tangent surface height H of the tangent blade is 65 mm; The widths of the two ends of the soil-throwing piece are smaller than the width of the middle part. The maximum length W of the soil-throwing piece is 120 mm, and the maximum width b is 60 mm.

2. The method for designing a soil throwing piece of a combined trenching blade according to claim 1, characterized in that: Here are the steps: The parameters that affect the distance of soil throwing are determined as follows: trenching depth, bending angle α of soil throwing piece and maximum width b of soil throwing piece; The trenching depth is the same as the height H of the cutting edge of the soil throwing piece, which is set to 65 mm; The bending angle α of the throwing piece is the relative bending angle from the soil entry point to the throwing point, that is, the bending shape of the throwing piece; so that the soil is gradually guided from the inner arc side of the throwing piece to the throwing direction; The maximum width b of the throwing blade determines the lateral distribution of the soil on the throwing blade. The soil is evenly distributed on the surface of the throwing blade during the throwing process. The maximum width b of the throwing blade ensures that the soil can quickly break away from the throwing blade during the throwing process and achieve the maximum throwing distance. Considering the soil particles as point masses, the soil moves in a parabolic motion when leaving the throwing piece. The distance the soil flies out of the throwing piece is: S=Bsinδ1 (3) Where, B—soil throwing distance, m S—lateral soil throwing distance, m v—initial velocity when thrown, m / s δ—Angle between the initial velocity and the ground when thrown, (°) δ1—projection of initial velocity v on the ground and v y Angle, (°) g—acceleration due to gravity, 9.8m 2 / s v x 、v y 、v z —The component of the initial (absolute) velocity v in the three-dimensional rectangular coordinate system of space, m / s And δ1 satisfies tanδ1=v y / v x Substituting formula (2) into formula (1) yields: The maximum width b of the throwing piece and the tilt angle γ of the throwing piece will affect v x 、v y 、v z , Establish the coordinate system oxyz, where point o is the center of rotation of the thrower, the positive direction of the y-axis is consistent with the forward direction of the machine, the x-axis is horizontal, the z-axis is vertical, and the front of the thrower handle is in the yoz plane; Then, take the intersection of the long and short sides of the cast-off piece as the coordinate origin o1, the short side as the x1 axis, and the long side as the y1 axis, and establish the coordinate system x1o1y1 on the cast-off piece plane. The x1o1y1 plane forms an angle γ with the yoz plane, which is the inclination angle of the cast-off piece, and the x1o1y1 plane forms an angle β with the xoy plane. According to the angle relationship between the soil throwing piece and the soil cutting knife rotation center coordinate system yoz, xoy, v x 、v y 、v z Expressed as: Where: r1—the radius of gyration of the intersection o1 of the long side and short side of the soil throwing piece near the end of the soil cutting knife, in m; the long side is on the y1 axis and the short side is on the x1 axis; v r —Relative speed of soil sliding on the surface of the dumping piece, m / s ω—grooving knife rotational angular velocity, rad / s v m —Soil speed along with trencher, m / s v a — Speed ​​of soil dragged by the combined trenching blade (12) during rotation, m / s v x 、v y 、v z is the component of the absolute velocity v in the three-dimensional rectangular coordinate system of space. The absolute velocity v of the soil on the throwing piece (13) is the involved velocity v driven by the rotation of the throwing and cutting combined trenching knife (12). a , the relative speed v of soil sliding on the surface of the soil throwing piece (13) r , soil moves along with the trencher's forward speed v m The vector sum of , v r 、v a 、v m The velocity components are v in the three-dimensional rectangular coordinate system of space. x ,v y ,v z , and then perform vector summation after solving it separately to obtain the absolute velocity v of the soil to determine its projectile trajectory; The velocity v a The direction is the negative direction of the y-axis, and the calculation formula is: Where: x'1—the instantaneous horizontal coordinate of the soil particle on the soil throwing sheet (13), δ2—Angle between r1 and y axis, (°) The soil is subjected to the combined effects of gravity, centrifugal force, Coriolis force and friction under the rotation of the thrower. The components of gravity on the x1 axis and y1 axis are G x , G y are mgsinγcosβ; the components of the centrifugal force on the x1 and y1 axes are F lx 、F ly The calculation formula is: Let k = cosβcosγ, the components of the Coriolis force on the x1 and y1 axes are F gx 、F gy for: Let k1 = ω 2 (r1cosδ2-x'1cosβ), the component of friction force F on the x1 and y1 axes fx 、F fy for: F fx =mfsinρ(sinβ(gsinγ+k1)+2v r ω(cosρsinγ+sinρ)cosβ) (9) Where ρ is the angle between the soil relative velocity and the x1 axis (°) F—Friction factor between soil particles and the surface of the throwing piece According to the geometric relationship, the relative velocity v r Direction meets: When the soil slides from the side cutting part and tangential part of the combined trenching cutter to the y1 axis of the soil throwing piece, the relative speed v r The direction coincides with the x1 axis, so the angle ρ is 0°, and at this time the soil is only affected by gravity and centrifugal force, then formula (9) is derived as: g=-ωcosβ(r1cosδ2+x'1cosβ)tanγ (11) According to the trenching depth, the end face height H of the combined trenching cutter is set to 65mm, the curves of the tangential and side cutting edges remain unchanged, and the turning radius r1 of point o1 is set to 230mm. Then, the turning radius angle δ2 of point o1 is set to 60°, so that the tool can ensure the motion trajectory and throwing effect of the soil throwing piece during the rotation process; The material of the soil throwing piece is manganese steel, and the friction coefficient f between it and the soil is 0.

65. When the soil slides in contact with the soil throwing piece, the sliding speed and movement direction of the soil are guaranteed; Since the tangent part of the throwing piece and the throwing and cutting combined trenching knife is also inclined along the bending line MK, and the inclination angle is consistent with the bending angle α of the tangent part, the angle β formed by the coordinate system x1o1y1 plane established on the throwing piece plane and the xoy plane is consistent with the bending angle α of the throwing and cutting combined trenching knife, both of which are 30°, that is, β＝α＝30°； Set the forward speed v of the machine with the combined trenching blade installed m is 0.5m / s; the shaft speed of the furrowing cutter is 200r / min, so ω is 20.94rad / s; according to the agronomic requirement of throwing soil to the furrow edge with a maximum width of 100mm, the width of the soil throwing, that is, the horizontal distance of the soil throwing S is taken as 100mm, and the unknowns γ, b, and v are solved by the above formulas (3), (8), and (9): r , use elimination method to eliminate v r Finally, we get γ = 30°, x'1 = 60 mm, and the maximum width b of the soil throwing piece is equal to the instantaneous horizontal coordinate x'1 of the soil particles on the soil throwing piece, that is, b = 60 mm; Where γ is the angle formed by the x1o1y1 plane and the yoz plane; β is the angle between the x1o1y1 plane and the xoy plane.

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