Combined ditching cutter with soil throwing pieces and design method of soil throwing pieces of combined ditching cutter

Abstract

The invention discloses a combined ditching cutter with a soil throwing sheet and a design method of the soil throwing sheet, and belongs to the technical field of ditching cutters. The combined ditching cutter with the soil throwing pieces comprises an arc-shaped soil cutting cutter and the soil throwing pieces arranged on the arc-shaped soil cutting cutter, the soil throwing pieces are arc-shaped bent blades and are arranged on the inner arc side of the soil cutting cutter, the working end portions of the soil throwing pieces are close to a tangent blade of the soil cutting cutter, and the distance L between the mass center of each soil throwing piece and the top end of the angle of the tangent blade of the soil cutting cutter is 50. According to the design method, the bending angle alpha of the soil throwing piece is 30 degrees, and the maximum width b of the soil throwing piece is 60 mm. When the combined ditching cutter is installed on a ditching cutter head for ditching, it can be guaranteed that the overall ditching width is smaller than or equal to 100 mm, and efficient ditching can be guaranteed while soil disturbance is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural machinery, and in particular relates to a combined trenching knife with a soil throwing piece and a design method of the soil throwing piece. Background Art

[0002] The traditional fertilization trenching knife has a large trenching width. Although a larger trenching width can increase the contact area of ​​the fertilizer, it also causes greater disturbance to the soil. During the operation process, overly wide trenching will damage the growth of fruit trees and damage the soil structure, affecting the air permeability and water retention of the soil. In addition, the existing trenching blades do not combine the advantages of soil cutting knives and soil throwing knives. During the operation process, they will cause great damage to the root system of fruit trees and cannot be adjusted according to the distribution of the root systems of different fruit trees, resulting in the root system of fruit trees being easily cut off during the trenching process, seriously affecting the healthy growth of fruit trees. Summary of the invention

[0003] In view of the above-mentioned technical problems, the present invention provides a combined trenching knife and a design method thereof, aiming to improve the suitability of the trenching width and reduce damage to fruit trees and soil.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The present invention discloses a combined trenching knife with a soil throwing piece, comprising an arc-shaped soil cutting knife and a soil throwing piece arranged thereon, wherein the soil throwing piece is an arc-shaped curved blade, which is arranged on the inner arc side of the soil cutting knife, and 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 centroid of the soil throwing piece and the top of the positive cutting edge angle of the soil cutting knife is 50, forming a curved shape toward the positive cutting edge end and the inner side of the soil cutting piece, and the bending angle α is 30 degrees.

[0006] Furthermore, the soil cutter is an arc-shaped knife with a curved surface bent to one side at the end, the bent portion at the end is a tangent portion, the side cutting portion is transitionally connected to it, the root 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 bent toward the curved surface, the end of the tangent portion is a tangent blade, which is an angular structure, and the tangent surface of the tangent blade is close to the end of the outer side cutting blade; 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 outward.

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

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

[0009] The design method of the soil throwing piece of the combined trenching knife of the present invention comprises the following steps:

[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 tangential edge height H of the soil throwing blade, which is set to 65 mm;

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

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

[0014] Considering soil particles as point masses, the soil moves in a parabolic trajectory when leaving the throwing piece. The distance of the soil flying 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 earth-throwing piece and the inclination angle γ of the earth-throwing piece will affect v x、v y 、v z ,

[0028] Establish the coordinate system oxyz, where point o is the rotation center 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 side and the short side of the earth-casting piece as the coordinate origin o1, the short side as the x1 axis, the long side as the y1 axis, and establish the coordinate system x1o1y1 on the earth-casting piece plane. The x1o1y1 and yoz plane form an angle γ, that is, the inclination angle of the earth-casting piece, and the x1o1y1 plane and the xoy plane form an angle β;

[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 It is expressed as:

[0031]

[0032] Where:

[0033] r1—is the radius of gyration of the intersection o1 of the long side and the short side of the soil throwing piece near the end of the soil cutting knife, 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 rotation angular velocity, rad / s

[0036] v m —Soil moving forward along with the trencher, m / s

[0037] v a —Soil dragging speed driven by 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 soil throwing piece 13 is the involved velocity v driven by the rotation of the combined throwing and cutting trenching knife 12. a , the relative speed v of soil sliding on the surface of the soil throwing piece 13 r , soil moves with the forward speed of the trencher v m The vector sum of r 、v a 、v m The velocity components in the three-dimensional rectangular coordinate system are v x,v y ,v z , and then solve it separately and perform vector summation to obtain the absolute velocity v of the soil to determine its projectile motion trajectory;

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

[0040]

[0041] Where: x'1—the instantaneous horizontal coordinate of soil particles on the soil throwing piece 13,

[0042] δ2—Angle between r1 and y axis, (°)

[0043] The soil is subjected to the combined effects of gravity, centrifugal force, Coriolis force and friction under the rotation of the thrower. The gravity component G on the x1 axis and y1 axis is x , G y are mgsinγcosβ; the centrifugal force components F on the x1 and y1 axes lx 、F ly The calculation formula is:

[0044]

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

[0046]

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

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

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

[0050] F—Friction factor between soil particles and the surface of the throwing piece

[0051] According to the geometric relationship, the relative speed v r Direction meets:

[0052]

[0053] When the soil slides from the side cutting part and tangent part of the combined trenching knife 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 equation (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 tangent edge and the side cutting edge remain unchanged, and the turning radius r1 of point o1 is set to 230mm, then the turning radius wrap angle δ2 of point o1 is 60°, so that the tool can ensure the motion trajectory and soil throwing effect of the soil throwing piece during the rotation process;

[0056] The soil throwing piece is made of manganese steel, and the friction coefficient f between it and the soil is 0.65. When the soil and the soil throwing piece come into contact and slide, the sliding speed and movement direction of the soil are guaranteed;

[0057] Since the tangent part of the throw-and-cut 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 throw-and-cut plane and the bending angle α of the throw-and-cut combined trenching knife is consistent with 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 trenching cutter is 200r / min, then ω is 20.94rad / s; according to the agronomic requirement that the maximum width of soil thrown to the ditch edge is 100mm, the width of soil thrown, that is, the horizontal distance of soil thrown S is taken as 100mm. 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] Among them, γ is the angle formed by the x1o1y1 plane and the yoz plane;

[0061] β is the angle formed by 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 is composed of an arc-shaped soil cutting knife and a soil throwing piece arranged thereon. The soil throwing piece is an arc-shaped curved blade, which is arranged on the inner arc side of the soil cutting knife. The working end of the soil throwing piece is close to the tangential edge of the soil cutting knife. The distance L between the center of mass of the soil throwing piece and the top of the tangential edge angle of the soil cutting knife is 50 mm, forming a bending shape toward the tangential 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 combined trenching knife and the soil throwing piece 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 the 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, and it is also helpful to cut off the crop roots in the soil.

[0065] 3. The optimized layout of the combined trenching blades of the present invention allows the machine to cause less overall disturbance to the soil during operation, especially in orchards where it is necessary to protect the organic structure of the soil 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 soil cutting knife.

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

[0070] Figure 5 This is a 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 schematic diagram for analyzing the soil throwing process of the combined trenching knife.

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

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

[0075] In the figure: 1. combined trenching knife, 11. soil cutting knife, 111. front cutting edge, 112-front cutting part, 113-side cutting edge, 114. knife handle, 115. side cutting part, 116. front cutting surface 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: Figure 1-Figure 8 As shown, the combined trenching knife 1 with a soil-throwing piece includes an arc-shaped soil-cutting knife 11 and a soil-throwing piece 12 arranged thereon, wherein the soil-throwing piece 12 is an arc-shaped curved blade, which is arranged on the inner arc side of the soil-cutting knife 11, and the working end of the soil-throwing piece 12 is close to the tangential edge of the soil-cutting knife 11, and the distance L between the center of mass of the soil-throwing piece 12 and the top of the tangential edge angle of the soil-cutting knife 11 is 50, forming a bending shape toward the tangential edge end and the inner side of the soil-cutting piece 11, and the bending angle α is 30°, that is: α is the inclination angle of the line from the top of the soil-throwing piece to the root of the curve relative to the intersection surface of the side cutting part and the tangential part of the soil-cutting knife.

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

[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 soil cutting knife facing the rotation direction of the trenching knife disc.

[0080] The soil throwing process of the combined trenching knife 12 is analyzed as follows: 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 soil will have more kinetic energy, 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, which 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, thus 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 soil throwing piece determines the direction in which the soil is thrown. In the design of the soil throwing piece, the bending angle affects the trajectory of the soil flying out of the soil throwing piece and the initial throwing angle of the soil. The bending angle α of the soil throwing piece is the relative bending angle from the soil entry point to the throwing point, that is, the bending shape of the soil throwing piece; the soil is gradually guided from the inner arc side to the throwing direction, so that it has a certain throwing angle when leaving the soil throwing piece. 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°. In practical applications, the bending angle α is adjusted according to the specific working conditions to maintain the best throwing effect under different soil conditions, which can not only ensure sufficient throwing distance, but also reduce soil disturbance.

[0084] The maximum width b of the throwing piece directly affects the contact area between the soil and the throwing piece, and further affects the grabbing ability and throwing efficiency of the throwing piece on the soil; the soil is evenly distributed on the surface of the throwing piece during the throwing process, increasing the stability of the throwing; the width of the throwing piece determines the lateral distribution of the soil on the throwing piece, and a larger width can grab more soil, increase the initial kinetic energy of the soil, and further increase the throwing distance; however, if the width is too large, the soil may not be able to leave the throwing piece smoothly, causing soil retention; therefore, the width b of the throwing piece ensures that the soil can quickly leave the throwing piece during the throwing process to achieve the maximum throwing distance;

[0085] The specific algorithm is: consider the soil particles as particles, the soil moves in a parabolic motion when leaving the throwing piece, and 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 earth-throwing piece and the inclination angle γ of the earth-throwing piece will affect v x 、v y 、v z In order to find the maximum width b and inclination angle γ of the thrown soil piece, 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 soil 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 handle surface of the soil cutter on the blade side of the soil cutter is located in the yoz plane;

[0100] Because the required inclination angle γ and the maximum width b of the earth-throwing piece are related to the earth-throwing piece plane, in order to conveniently represent the relevant parameters of the earth-throwing piece, the intersection of the long side and the short side of the earth-throwing piece is taken as the coordinate origin o1, the short side is the x1 axis, and the long side is the y1 axis. The coordinate system x1o1y1 is established on the earth-throwing piece plane. The x1o1y1 and yoz planes form an angle γ, and the x1o1y1 plane and the xoy plane form an angle β.

[0101] 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 It is expressed as:

[0102]

[0103] Where:

[0104] r1—is the radius of gyration of the intersection o1 of the long side and the short side of the soil throwing piece near the end of the soil cutting knife, m; the long side is on the y1 axis and the short side is on the x1 axis;

[0105] v r —Relative speed of soil sliding on the surface of the dumping piece, m / s

[0106] ω—grooving knife rotation angular velocity, rad / s

[0107] v m —Soil moving forward along with the trencher, m / s

[0108] v a —Soil dragging speed driven by the combined trenching blade 12, m / s

[0109] 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 soil throwing piece 13 is the involved velocity v driven by the rotation of the combined throwing and cutting trenching knife 12. a , the relative speed v of soil sliding on the surface of the soil throwing piece 13 r , soil moves with the forward speed of the trencher v m The vector sum of r 、v a 、v m The velocity components in the three-dimensional rectangular coordinate system are v x ,v y ,v z , solve it separately and then perform vector summation to get the absolute velocity v of the soil to determine its trajectory of projection; the vector sum not only determines the total velocity of the soil, but also determines the direction in which the soil is thrown. Different velocity components will affect the soil in different directions. The vector sum can determine the final projection angle and distance of the soil; the magnitude and direction of the absolute velocity will directly affect the trajectory and distance of the soil;

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

[0111]

[0112] Where: x'1—the instantaneous horizontal coordinate of soil particles 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 dump sheet 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 acted upon by gravity, centrifugal force, Coriolis force and friction force under the action of the soil thrower. The gravity component G on the x1 axis and y1 axis is x , G y are mgsinγcosβ; the centrifugal force components F on the x1 and y1 axes lx 、F ly The calculation formula is:

[0115]

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

[0117]

[0118] Let k1 = ω 2 (r1cosδ2-x'1cosβ), the friction force component 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 speed 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 equation (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 tangent edge and the side cutting edge remain unchanged, and the turning radius r1 of point o1 is set to 230mm. Then the turning radius wrap angle δ2 of point o1 is 60°, which is to ensure the stability of the motion trajectory of the soil throwing piece and the soil throwing effect during the rotation of the cutter, and ensure that the cutter can smoothly complete the functions of cutting and throwing soil when rotating;

[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 may increase the cutting angle, resulting in excessive soil resistance; too small a height may result in insufficient cutting depth, affecting work efficiency; at the same time, it can ensure the appropriate block size of the soil after cutting to avoid 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 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] The material of the soil throwing piece 13 in this example is manganese steel, and the soil is mostly sandy loam, and the friction coefficient f between the soil and the soil is 0.65. The friction coefficient f describes the friction between the soil throwing piece and the soil. The friction plays an important role in the entire soil throwing process, especially when the soil and the soil throwing piece are in contact and sliding, the 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 knife 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 knife 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 trenching cutter is 200r / min, then ω is 20.94rad / s; according to the agronomic requirement that the maximum width of soil thrown to the ditch edge is 100mm, the width of soil thrown, that is, the horizontal distance of soil thrown S is taken as 100mm. 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, it is obtained that γ = 30°, x'1 = 60 mm, 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] Among them, γ is the angle formed by the x1o1y1 plane and the yoz plane;

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

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

[0134] When the present invention is used, Fig. 9 , Fig.10 As shown, a plurality of 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 arranged 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 arranged 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 spaced at the same intervals, and are respectively staggered on both sides of the trenching disc 2; soil cutting knives 11 and combined trenching knives 1 are respectively arranged on the discs on both sides of the trenching disc 2 at an interval of 180 degrees.

[0135] The radius of the trenching disc 2 is 800mm, the radius of the soil cutting knife 11 and the combined trenching knife 12 arranged on the two side discs of the trenching disc 2 is 300mm; the thickness of the trenching disc 2 is 50mm, and the trenching width can be 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 rotation speed of the cutter disc of the trenching machine, it is first necessary to determine the appropriate setting according to the soil type. For example, for heavy clay soil, 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, and at the same time, the rotation speed of the cutter disc is increased to about 250rad / min to 286.62rad / min to enhance the cutting effect and reduce the burden of the machine. For the case of a deeper trenching depth, a slower forward speed (about 0.4m / s to 0.5m / s) helps to ensure the accuracy and depth of excavation, and at the same time, the rotation speed of the cutter disc can be set in a medium to high range (about 200rad / min to 286.62rad / min) to meet 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 protection scope of the present invention.

Claims

1. A combined trenching knife with a soil throwing blade, characterized in that: It includes an arc-shaped soil cutting knife and a soil throwing piece arranged on it, wherein the soil throwing piece is an arc-shaped curved blade, which is arranged on the inner arc side of the soil cutting knife, and the working end of the soil throwing piece is close to the tangential edge of the soil cutting knife. The distance L between the center of mass of the soil throwing piece and the top of the tangential edge angle of the soil cutting knife is 50, forming a curved shape toward the tangential edge end and the inner side of the soil cutting piece, and the bending angle α is 30°.

2. The combined trenching knife with a soil throwing blade according to claim 1, characterized in that: The soil cutting knife is an arc-shaped knife with a curved surface bent to one side at the end, the bent part at the end is the tangent part, the side cutting part is transitionally connected to it, the root is the knife handle, the side cutting part and the outside of the tangent part form an outer side cutting edge, the outer side cutting edge is an arc-shaped structure with an end bent to the curved surface, the end of the tangent part is the tangent blade, which is an angular structure, and the tangent surface of the tangent blade is close to the end of the outer side cutting blade; the curved surfaces of the soil cutting knives installed on both sides of the trenching cutter disc are opposite to each other, that is, the curved surfaces face outward.

3. The combined trenching knife with a soil throwing blade according to claim 1, characterized in that: The tangent surface height H of the tangent blade is 65 mm.

4. The combined trenching knife with a soil throwing blade according to claim 1, characterized in that: 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 120 mm, and the maximum width b is 60 mm.

5. The method for designing a soil throwing piece of a combined trenching knife according to any one of claims 1 to 4, 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 tangential edge height H of the soil throwing blade, which is set to 65 mm; The bending angle α of the soil throwing piece is the relative bending angle from the soil entry point to the throwing point, that is, the bending shape of the soil throwing piece; so that the soil is gradually guided from the inner arc side of the soil throwing piece to the throwing direction; The maximum width b of the throwing piece determines the lateral distribution of the soil on the throwing piece. The soil is evenly distributed on the surface of the throwing piece during the throwing process. The maximum width b of the throwing piece ensures that the soil can quickly break away from the throwing piece during the throwing process to achieve the maximum throwing distance. Considering soil particles as point masses, the soil moves in a parabolic trajectory when leaving the throwing piece. The distance of the soil flying 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 initial velocity and 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 earth-throwing piece and the inclination angle γ of the earth-throwing piece will affect v x 、v y 、v z , Establish the coordinate system oxyz, where point o is the rotation center 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 side and the short side of the earth-casting piece as the coordinate origin o1, the short side as the x1 axis, the long side as the y1 axis, and establish the coordinate system x1o1y1 on the earth-casting piece plane. The x1o1y1 and yoz plane form an angle γ, that is, the inclination angle of the earth-casting piece, and the x1o1y1 plane and the xoy plane form an angle β; 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 It is expressed as: Where: r1—is the radius of gyration of the intersection o1 of the long side and the short side of the soil throwing piece near the end of the soil cutting knife, 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 rotation angular velocity, rad / s v m —Soil moving forward along with the trencher, m / s v a —Soil dragging speed driven by the combined trenching blade 12, 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 soil throwing piece 13 is the involved velocity v driven by the rotation of the combined throwing and cutting trenching knife 12. a , the relative speed v of soil sliding on the surface of the soil throwing piece 13 r , soil moves with the forward speed of the trencher v m The vector sum of r 、v a 、v m The velocity components in the three-dimensional rectangular coordinate system are v x ,v y ,v z , and then solve it separately and perform vector summation to obtain the absolute velocity v of the soil to determine its projectile motion 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 soil particles on the soil throwing piece 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 gravity component G on the x1 axis and y1 axis is x , G y are mgsinγcosβ; the centrifugal force components F on the x1 and y1 axes lx 、F ly The calculation formula is: Let k = cosβcosγ, the component F of the Coriolis force on the x1 and y1 axes gx 、F gy for: Let k1 = ω 2 (r1cosδ2-x'1cosβ), the friction force component F on the x1 and y1 axes fx 、F fy for: F Gx =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 speed v r Direction meets: When the soil slides from the side cutting part and tangent part of the combined trenching knife 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 equation (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 tangent edge and the side cutting edge remain unchanged, and the turning radius r1 of point o1 is set to 230mm, then the turning radius wrap angle δ2 of point o1 is 60°, so that the tool can ensure the motion trajectory and soil throwing effect of the soil throwing piece during the rotation process; The soil throwing piece is made of manganese steel, and the friction coefficient f between it and the soil is 0.

65. When the soil and the soil throwing piece are in contact and sliding, the sliding speed and movement direction of the soil are guaranteed; Since the tangent part of the soil throwing piece and the combined throwing and cutting trenching knife are also inclined along the bending line MK, and the inclination angle is consistent with the bending angle α of the tangent part, therefore, the angle β formed by the x1o1y1 plane and the xoy plane of the coordinate system established on the soil throwing piece plane is consistent with the bending angle α of the combined throwing and cutting 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 trenching cutter is 200r / min, then ω is 20.94rad / s; according to the agronomic requirement that the maximum width of soil thrown to the ditch edge is 100mm, the width of soil thrown, that is, the horizontal distance of soil thrown S is taken as 100mm. 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; Among them, γ is the angle formed by the x1o1y1 plane and the yoz plane; β is the angle formed by the x1o1y1 plane and the xoy plane.

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