Coupling bionic low-interference and resistance-reducing subsoiler based on mouthparts of larvae of Nepieca cognita

Abstract

A coupling bionic low-disturbance and resistance-reducing subsoiler based on a halftone mantidis larva mouthpart is composed of a bionic subsoiler handle and a bionic subsoiler tip. The bionic subsoiling shovel handle is formed by connecting a rack connecting section, a working section and a shovel tip connecting section, wherein a shovel handle cutting edge contour line, a shovel handle working section inner directrix and a shovel handle working outer directrix are all designed according to an inner contour curve of a halitosis of a halitosis of a halitosis of the halitosis of the halitosis of the halitosis of the halitosis of the halitosis; and the soil contact working surface of the bionic shovel tip and the left and right resistance reduction surfaces of the shovel tip are formed by the outer contour curve of the mouthpart of the halita straightella larva. A curvilinear equation is obtained through reverse engineering, through optimization design, inner and outer contour curves of the mouthparts of the halitosis straighteiensis larvae are applied to the design of the subsoiling shovel handle and the subsoiling shovel tip, the specific bionic structure of the subsoiling shovel reduces the operation resistance by 20.71% in the subsoiling operation process, the earth surface undulation degree coefficient of soil can be reduced by 25.19%, and the subsoiling shovel has a good resistance reduction effect; the surface undulation degree can be further reduced, the surface flatness is improved, a good seedbed condition is provided for subsequent seeding, and the uniformity of the seeding depth is improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural tillage machinery and equipment technology, specifically to a deep loosening shovel based on the coupled biomimetic low-disturbance drag-reducing mechanism of the mouthparts of the larvae of the mayfly beetle. Background Technology

[0002] Mechanized subtilizing is a core technology in modern agricultural conservation tillage systems. It aims to break up the hardened plow pan formed by long-term shallow tillage and rotary tillage, without disrupting the original soil structure, by using large and medium-sized tractors to pull subtilizing implements. This improves the topsoil structure and promotes deeper root penetration and soil moisture. The subtilizing shovel is the most important working component, mainly composed of the shovel handle and the shovel tip. During mechanized subtilizing, the resistance is very high, resulting in high fuel consumption. Furthermore, poor surface evenness leads to unstable seed sowing depth after planting, affecting crop germination rate and growth. Therefore, optimizing the structure of the subtilizing shovel to reduce resistance and improve surface evenness after subtilizing is crucial for promoting the application of mechanized subtilizing technology.

[0003] Currently, the mainstream subsoil shovels on the market still use the national standard rounded or straight handles, while the shovel tips commonly employ chisel-shaped, arrow-shaped, or double-wing designs. These designs still suffer from problems such as high resistance, high fuel consumption, and poor surface smoothness. In recent years, bionics has developed rapidly, and many researchers have applied bionic principles to the design of subsoil shovels. For example, the patent CN115735436A, "Coupled Bionic Drag-Reducing Subsoil Shovel Based on the Lateral Contour Curve of a Cicada's Head," can reduce subsoil operation resistance by 12.73%; and the patent CN103797906B, "Bionic Drag-Reducing Subsoil Shovel Handle Based on a Power Function Curve," can reduce subsoil operation resistance by 9%. However, previous biomimetic designs of subsoil machinery have rarely considered the surface smoothness after subsoiling. If a new type of coupled biomimetic drag reduction is proposed, it can reduce soil disturbance, improve the surface smoothness after subsoiling, and increase the drag reduction rate of the machinery, thereby further reducing fuel consumption for subsoiling and improving the uniformity of sowing depth and seed germination rate after subsoiling.

[0004] Research has revealed that the grub-like larvae of the *Ephedra sinica* can move freely in the soil and feed on plant roots and tubers using their mouthparts. This is significantly related to the inner and outer contours of their mouthparts. When feeding on roots, they open their mouthparts to disturb the surrounding soil, exposing the roots, and then close their mouthparts to sever the roots. Therefore, applying the inner and outer contours of the grub-like mouthparts of the *Ephedra sinica* larvae to the structure of deep-plowing shovel handles and tips has a strong theoretical basis. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a coupled biomimetic low-disturbance drag-reducing deep tillage shovel based on the mouthparts of a mayfly larva, thereby reducing tillage resistance, lowering fuel consumption during deep tillage operations, and improving the surface smoothness after deep tillage.

[0006] The technical solution adopted in this invention is: a coupled biomimetic low-drag deep loosening shovel based on the mouthparts of the larvae of the mayfly, which consists of a biomimetic deep loosening shovel handle and a biomimetic shovel tip.

[0007] The biomimetic deep tillage shovel handle is composed of a frame connecting section, a handle working section, and a shovel tip connecting section connected sequentially. The handle working section has a shovel handle cutting edge contour line, an inner guideline, and an outer guideline. The inclined surface between the shovel handle cutting edge contour line and the inner guideline is the cutting edge inclined surface of the biomimetic deep tillage shovel handle. The shovel handle cutting edge contour line, the inner guideline, and the outer guideline are all concave in the same direction and are obtained by proportionally enlarging the same biomimetic curve. The equation of this biomimetic curve is: ,in .

[0008] The soil contact surface and the drag-reducing surface at the tip of the biomimetic shovel are both designed with biomimetic curves. ,in .

[0009] As a preferred embodiment, the cross-sectional profile curve of the beveled cutting edge forms the cutting edge element line. This cutting edge element line of the shovel handle consists of two symmetrically arranged curves, with the included angle between the two curves being... The angle is 55-60°.

[0010] As a preferred embodiment, the profile of the cutting edge of the shovel handle is parallel to the inner guideline of the working section of the shovel handle, and the angle between the tangent and the vertical direction of the frame connection section is... (Lean angle) is 15-45°.

[0011] As a preferred embodiment, the angle between the shovel tip connecting section and the horizontal plane (Entry angle) is 18-38°.

[0012] As a preferred embodiment, the angle between the shovel tip connecting section and the horizontal plane It is 33°.

[0013] As a preferred embodiment, the frame connecting section is provided with a plurality of mounting holes, which are spaced apart along the length of the frame connecting section.

[0014] As a preferred embodiment, the bionic shovel tip is formed by the connection of the shovel handle surface, the soil contact working surface, the left drag-reducing surface of the shovel tip, the right drag-reducing surface of the shovel tip, the left side of the shovel tip, and the right side of the shovel tip. The left drag-reducing surface of the shovel tip and the right drag-reducing surface of the shovel tip are connected to the left side of the shovel tip and the right side of the shovel tip, respectively, and the front parts of the left drag-reducing surface of the shovel tip and the right drag-reducing surface of the shovel tip are connected.

[0015] As a preferred embodiment, the soil-contacting working surface is based on the outer contour curve of the mouthparts of the mayfly larva. It was produced by proportional enlargement and lateral stretching, wherein The horizontal distance between the two endpoints is The standard length of the chisel tip is The magnification ratio is The lateral stretching distance is , The width of the chisel tip is set to the national standard, resulting in a biomimetic chisel tip working surface that contacts the soil.

[0016] As a preferred embodiment, the drag-reducing surface at the tip of the shovel is composed of a drag-reducing surface on the left side of the shovel tip and a drag-reducing surface on the right side of the shovel tip, wherein the drag-reducing surface on the left side of the shovel tip is based on the outer contour curve of the mouthparts of the larvae of the mayfly beetle. It was produced by proportional enlargement and lateral stretching, wherein The vertical distance between the two endpoints of the curve is The magnification ratio is , The width of the chisel tip according to national standards Half of it is used to obtain the drag-reducing surface on the left side of the shovel tip, and then the drag-reducing surface on the right side of the shovel tip is obtained through symmetry.

[0017] The beneficial effects of this invention are: This invention, through optimized design, utilizes the coupled biomimetic low-drag deep loosening shovel based on the mouthparts of the mayfly larvae. Its inner contour is applied to the contour design of the biomimetic deep loosening shovel handle, and its outer contour is applied to the contour design of the biomimetic shovel tip. Its unique biomimetic drag-reducing structure can effectively reduce the shear friction and adhesion resistance between soil particles and the deep loosening shovel during deep loosening operations, thereby achieving energy-saving effects. Its low-energy consumption characteristics are in line with the concept of green agricultural development, reducing carbon emissions and environmental damage during cultivation, and providing technical equipment support for ecological agriculture and sustainable agricultural production.

[0018] In the research process, we may introduce two parameters, the drag reduction rate of horizontal tillage and the surface undulation coefficient, to measure the optimization effect of the coupled biomimetic low-disturbance drag reduction deep loosening shovel based on the mouthparts of the larvae of the Ephemeris chinensis.

[0019] Formula for drag reduction rate in horizontal tillage: , For drag reduction ratio, The horizontal tillage resistance of a standard circular arc-shaped deep tillage shovel (unit: N). The horizontal tillage resistance (in N) of a deep loosening shovel based on the coupled biomimetic low-disturbance drag-reducing shovel of the mouthparts of the mayfly larva.

[0020] Formula for the coefficient of surface relief: For the first The vertical distance from the ground surface to the horizontal baseline before and after deep soil loosening was measured (unit: mm). For the first In the second measurement Vertical distances (in mm) from the ground surface before and after deep loosening at each of the three equally divided points to the horizontal baseline. For the first Number of test points in this measurement For the first The surface relief coefficient of this measurement (unit: mm).

[0021] Discrete element simulation results show that, under different tillage depths (250-350mm) and tillage speeds (0.5-3m / s), using this coupled biomimetic drag-reducing deep tillage shovel based on the inner and outer contour curves of the mouthparts of the Echinochloa crus-galli larva can reduce the drag of deep tillage operations by 20.71% compared to the national standard circular arc deep tillage shovel, and reduce the surface undulation coefficient by 25.19%. This proves that the present invention can provide a good drag reduction effect for mechanized deep tillage operations, and can further reduce the surface undulation, improve the surface flatness, provide good seedbed conditions for subsequent sowing, and improve the uniformity of sowing depth. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the deep loosening shovel based on the mouthparts of the larvae of the mayfly, as described in this invention. Figure 2 This is a schematic diagram of the structure of the biomimetic deep loosening shovel handle described in this invention; Figure 3 This is a left view of the biomimetic deep loosening shovel handle described in this invention; Figure 4 This is an isometric view of the biomimetic shovel tip described in this invention; Figure 5 This is a top view of the biomimetic shovel tip described in this invention; Figure 6 The inner contour curve of the mouthparts of a larvae of the mayfly beetle; Figure 7 The outer contour curve of the mouthparts of a larvae of the mayfly beetle; Figure 8 A biomimetic curve diagram of a biomimetic deep-loosening shovel handle; Figure 9 A biomimetic curve diagram of a biomimetic shovel tip; Figure 10 The graph shows the variation of horizontal tillage resistance of a deep loosening shovel based on the coupled biomimetic low-disturbance drag-reducing shovel of the larvae of the Ephemeral beetle under different soil entry angles. Figure 11 The figure shows a comparison of the horizontal tillage resistance of the biomimetic low-disturbance drag-reducing deep tillage shovel based on the coupling of the mouthparts of the Ephedra sinica larva and the national standard arc-shaped deep tillage shovel when the tillage depth is 250-300mm. Figure 12 A comparison diagram of the horizontal tillage resistance of the present invention's biomimetic low-disturbance drag-reducing deep tillage shovel based on the coupling of the mouthparts of the larvae of the Ephedra sinica and the national standard arc-shaped deep tillage shovel, under the condition of a horizontal tillage speed of 0.5-3 m / s. Figure 13 The graph shows the variation of horizontal tillage resistance of a coupled biomimetic low-disturbance drag-reducing deep tillage shovel based on the mouthparts of a mayfly larva under different back tilt angles. Figure 14 A comparison of the surface undulation coefficients after tillage using a national standard arc-shaped deep tillage shovel and a deep tillage shovel based on the mouthparts of a mayfly larvae. Figure 15 Comparison of the surface undulations after tillage with a national standard arc-shaped deep tillage shovel and a deep tillage shovel based on the mouthparts of a mayfly larva. Figure label: 1 is the biomimetic deep tillage shovel handle, 1-1 is the frame connection section, 1-2 is the deep tillage shovel mounting hole, 1-3 is the cutting edge contour line, 1-4 is the shovel handle working section, 1-5 is the inner guideline of the shovel handle working section, 1-6 is the outer guideline of the shovel handle working section, 1-7 is the shovel tip connection section, 1-8 is the first connection hole of the shovel handle, 1-9 is the second connection hole of the shovel handle, and 1-10 is the shovel handle cutting edge circle line; 2 is the biomimetic shovel tip, 2-1 is the connecting shovel handle surface, 2-2 is the soil contact working surface, 2-3 is the first connecting hole of the shovel tip, 2-4 is the second connecting hole of the shovel tip, 2-5 is the side of the shovel tip, and 2-6 is the drag-reducing surface at the front end of the shovel tip. Detailed Implementation

[0024] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0025] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," and similar words used in the specification and claims of this patent application do not express a limitation of quantity, but rather indicate the presence of at least one. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0026] The following is in conjunction with the appendix Figure 1-15 The structure, assembly, and working process of the biomimetic deep tillage shovel's handle and tip described in this invention are described in detail below: The biomimetic low-drag deep loosening shovel based on the mouthparts of the mayfly larvae described in this invention consists of a biomimetic deep loosening shovel handle 1 and a biomimetic shovel tip 2 connected by bolts. The biomimetic deep loosening shovel handle 1 is fixed to the mobile machinery through the deep loosening shovel mounting holes 1-2 on the frame connecting section 1-1, thus forming a complete machine required for deep loosening operations. Under the traction of the mobile machinery, mechanized deep loosening operations are carried out.

[0027] refer to Figure 1-5 This invention relates to a biomimetic low-drag deep loosening shovel based on the mouthparts of a *Synaps spp.* larvae, comprising a biomimetic deep loosening shovel handle 1 and a biomimetic shovel tip 2. The biomimetic deep loosening shovel handle 1 is designed based on the inner contour curve of the mouthparts of the *Synaps spp.* larvae, while the biomimetic shovel tip 2 is designed based on the outer contour curve of the mouthparts. The biomimetic deep loosening shovel handle 1 includes a frame connecting section 1-1, a deep loosening shovel mounting hole 1-2, a cutting edge contour line 1-3, a working section 1-4, an inner guideline 1-5, an outer guideline 1-6, a shovel tip connecting section 1-7, a first connecting hole 1-8, a second connecting hole 1-9, and a cutting edge line 1-10. The angle between the shovel tip connecting section 1-7 and the horizontal direction is... The (entry angle) is 18-38°, preferably 33° in this embodiment. The contour lines of the cutting edge of the deep tillage shovel handle 1-3, the inner guideline of the working section of the deep tillage shovel handle 1-5, and the outer guideline of the working section of the deep tillage shovel handle 1-6 are all derived from the equations of the biomimetic curves. ( The cutting edge contour lines 1-3 and 1-5 of the working section of the deep tillage shovel handle are obtained by proportional enlargement. They are parallel curves, and the angle between the end tangent and the vertical direction is... The lean angle is 15-45°. In this embodiment, the lean angle is... Preferably 30°, total height ; In this embodiment, the biomimetic shovel tip 2 includes a connecting shovel handle surface 2-1, a soil-contacting working surface 2-2, a first connecting hole 2-3 and a second connecting hole 2-4, a shovel tip side surface 2-5, and a drag-reducing surface 2-6 at the front end of the shovel tip. The soil-contacting working surface 2-2 and the drag-reducing surface 2-6 at the front end of the shovel tip are both derived from the equations of biomimetic curves. ( The length is obtained by proportionally enlarging and laterally stretching the material. , , , .

[0028] The reason why this design incorporates the inner and outer contours of the mouthparts of the Ephemeral beetle larva into the biomimetic design of the deep tillage shovel is based on the fact that the larvae disturb the soil with their mouthparts to gnaw on plant roots and tubers. Through the above design, the tillage resistance of the deep tillage shovel handle can be effectively reduced.

[0029] It should be noted that the biomimetic prototype used in this invention is the mouthparts of the larvae of the cricket beetle. The larvae of the cricket beetle are insects that live in the soil and feed on plant roots and tubers using their mouthparts. It is easy to see that their mouthparts have a good shearing effect when disturbing the soil and feeding on plant roots and tubers, indicating that the structural curve of their mouthparts has a good drag-reducing effect. Therefore, the contour curve of their mouthparts is applied to the drag-reducing design of the deep loosening shovel. For example... Figure 6-9 As shown, by scanning its mouthparts, two-dimensional photographs of both the front and back sides were obtained. These images were imported into AutoCAD software, and the software's spline curve control point command was used to draw its inner and outer contour curves. The coordinates of the curve points were collected, and curve fitting was performed using Excel software. The equations of the two fitted curves are as follows: ( , ), ( , ), the two fitted curves (A metric used in statistics to measure how well a regression model fits the data) The closer the value is to 1, the higher the degree of interpretation of the data and the better the fit. The values ​​are all close to 1, indicating a high degree of fit, which provides a reliable basis for the design.

[0030] Figure 10 The resistance diagram of the coupled biomimetic low-disturbance drag-reducing deep loosening shovel based on the mouthparts of the larvae of the scarab beetle is shown in the present invention under different soil entry angles (18-38°). The discrete element simulation test shows that when the soil entry angle is 33°, the horizontal tillage resistance of the coupled biomimetic low-disturbance drag-reducing deep loosening shovel based on the mouthparts of the scarab beetle of the present invention is the smallest, that is, the soil entry angle of 33° is the optimal soil entry angle of the present invention.

[0031] Figure 11-12 The figures show a comparison of the horizontal tillage resistance of the present invention's biomimetic low-drag reduction deep tillage shovel based on the mouthparts of the scarab beetle larvae and the standard circular arc-shaped deep tillage shovel under different tillage depths (250-350mm) and tillage speeds (0.5-3m / s). Discrete element simulation experiments show that, at different tillage depths, the present invention's biomimetic low-drag reduction deep tillage shovel based on the mouthparts of the scarab beetle larvae can reduce the horizontal deep tillage operation resistance by 20.71%; and at different tillage speeds, the present invention's biomimetic low-drag reduction deep tillage shovel based on the mouthparts of the scarab beetle larvae can reduce the horizontal deep tillage operation resistance by 20.23%.

[0032] Figure 13 For different back tilt angles (15-45°), the resistance diagram of the coupled biomimetic low-disturbance drag-reducing deep tillage shovel based on the mouthparts of the larvae of the scarab beetle described in this invention is shown by discrete element simulation test. The results show that when the back tilt angle is 30°, the horizontal tillage resistance of the coupled biomimetic low-disturbance drag-reducing deep tillage shovel based on the mouthparts of the scarab beetle described in this invention is the smallest. That is, the back tilt angle of 30° is the optimal back tilt angle of this invention.

[0033] Figure 14 To compare the surface undulation coefficient after tillage with the standard circular arc-shaped deep tillage shovel based on the mouthparts of the larvae of the scarab beetle (as described in this invention) under the same tillage depth and speed conditions, discrete element simulation experiments show that, under the same conditions, the surface undulation coefficient of the deep tillage shovel based on the mouthparts of the scarab beetle (as described in this invention) can be reduced by 25.19%, making it more suitable for deep tillage under conservation tillage conditions.

[0034] Figure 15 To compare the surface undulation profiles after tillage with the standard circular arc deep tillage shovel and the coupled biomimetic low-drag reduction deep tillage shovel based on the mouthparts of the larvae of the scarab beetle, under the same tillage depth and tillage speed conditions, the present invention provides a comparison of the surface undulation profiles after tillage with the standard circular arc deep tillage shovel and the coupled biomimetic low-drag reduction deep tillage shovel based on the mouthparts of the scarab beetle.

[0035] The names and dimensions of other unmarked parts are designed in accordance with the People's Republic of China Machinery Industry Standard JB / T9788-1999 "Deep Loosening Shovel and Deep Loosening Shovel Handle".

[0036] The parts not described in detail in this embodiment are existing technologies.

[0037] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A biomimetic low-disturbance drag-reducing deep loosening shovel based on the mouthparts of the larvae of the mayfly beetle, characterized in that: It consists of a biomimetic deep tillage shovel handle and a biomimetic shovel tip. The biomimetic deep tillage shovel handle is formed by sequentially connecting a frame connecting section, a shovel handle working section, and a shovel tip connecting section. The shovel handle cutting edge contour line, the inner guideline, and the outer guideline of the shovel handle working section are all concave and pass through the same biomimetic curve. Obtained by proportional scaling; the soil-contacting working surface and the drag-reducing surface at the tip of the biomimetic shovel are both derived from biomimetic curves. The inclined surface between the profile of the cutting edge of the shovel handle and the inner guideline of the working section of the shovel handle, obtained by proportional enlargement and transverse stretching, is the cutting edge inclined surface of the deep loosening shovel handle.

2. The deep loosening shovel based on the mouthparts of the mayfly larvae of the genus *Ephemeris* as described in claim 1, characterized in that: The biomimetic deep-loosening shovel handle has a cross-sectional profile curve on its upper cutting edge bevel that forms the shovel handle cutting edge element line. This cutting edge element line consists of two symmetrically arranged curves, with the included angle between the two curves being... The angle is 55°–60°.

3. The deep loosening shovel based on the mouthparts of the mayfly larva as described in claim 1, characterized in that: The biomimetic deep loosening shovel handle has a cutting edge profile that is parallel to the inner guideline of the working section of the shovel handle.

4. The deep loosening shovel based on the mouthparts of the mayfly larva as described in claim 3, characterized in that: The biomimetic deep loosening shovel handle has an angle between the profile of the shovel handle's cutting edge and the tangent line at the upper vertex of the inner guideline of the working section of the shovel handle, and the vertical direction. The range is 15-45°.

5. The deep loosening shovel based on the mouthparts of the mayfly larva as described in claim 1, characterized in that: The biomimetic deep tillage shovel handle has an angle between its upper tip connecting section and the horizontal plane. The range is 18-38°.

6. The deep loosening shovel based on the mouthparts of a mayfly larva as described in claim 5, characterized in that: The angle between the shovel tip connecting section and the horizontal plane It is 33°.

7. The deep loosening shovel based on the mouthparts of the mayfly larva as described in claim 1, characterized in that: The biomimetic deep loosening shovel handle has several mounting holes on the frame connecting section, and these mounting holes are spaced apart along the length of the frame connecting section.

8. The deep loosening shovel based on the mouthparts of the larvae of the mayfly beetle, as described in claim 1, is characterized in that: The biomimetic shovel tip is formed by the connection surface of the shovel handle, the working surface in contact with the soil, the drag-reducing surface at the front end of the shovel tip, and the side surface of the shovel tip.

9. The deep loosening shovel based on the mouthparts of a *Ephemeroptera litura* larva as described in claim 1 or 8, characterized in that: The soil contact working surface is based on the outer contour curve of the mouthparts of the mayfly larva. It was produced by proportional enlargement and lateral stretching, wherein The horizontal distance between the two endpoints is The standard length of the chisel tip is The magnification ratio is The lateral stretching distance is , The width of the chisel tip is set to the national standard, resulting in a biomimetic chisel tip working surface that contacts the soil.

10. The biomimetic shovel tip of the coupled biomimetic low-drag reduction deep loosening shovel based on the mouthparts of a mayfly larva as described in claim 1 or 8, characterized in that: The drag-reducing surface at the tip of the shovel is composed of a drag-reducing surface on the left side of the shovel tip and a drag-reducing surface on the right side of the shovel tip, wherein the drag-reducing surface on the left side of the shovel tip is based on the outer contour curve of the mouthparts of the larvae of the mayfly beetle. It was produced by proportional enlargement and lateral stretching, wherein The vertical distance between the two endpoints of the curve is The magnification ratio is , The width of the chisel tip according to national standards Half of it is used to obtain the drag-reducing surface on the left side of the shovel tip, and then the drag-reducing surface on the right side of the shovel tip is obtained through symmetry.

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