阅读说明：本技术 一种省力车刀仿生设计方法 (Bionic design method for labor-saving turning tool ) 是由 马晶 张明鉴 刘强 杨绍成 于 2021-09-03 设计创作，主要内容包括：一种省力车刀仿生设计方法,它属于机械金属切削和工程仿生学联合技术领域。本发明解决了传统刀具的切削效率低、切削负载大的问题。本发明从仿生学的角度出发,发现帽贝牙齿具有良好的切削性能。通过模仿帽贝牙齿的几何形状,来优化车刀几何形状。优化完成的刀具的前刀面为变曲率曲面,刀具前角随曲率变化,致使刀具在切削过程始终处于“变前角”切削状态,促使切屑弯曲,从而与刀具发生分离和断裂,减小刀具与切屑之间的接触长度,进而减小刀具与切屑之间的摩擦阻力,以减小切削负载,减小车刀在工作过程中的切削力,提高切削效率。本发明可以应用于对车刀进行设计。(A labor-saving turning tool bionic design method belongs to the technical field of mechanical metal cutting and engineering bionic combination. The invention solves the problems of low cutting efficiency and large cutting load of the traditional cutter. From the perspective of bionics, the invention discovers that the cap shell tooth has good cutting performance. The lathe tool geometry is optimized by mimicking the geometry of a calotte tooth. The front knife face of the optimized and finished cutter is a variable curvature curved surface, and the front angle of the cutter changes along with the curvature, so that the cutter is always in a variable front angle cutting state in the cutting process, cuttings are enabled to be bent, the cutter is separated from the cutter and broken, the contact length between the cutter and the cuttings is reduced, the friction resistance between the cutter and the cuttings is further reduced, the cutting load is reduced, the cutting force of the lathe tool in the working process is reduced, and the cutting efficiency is improved. The invention can be applied to the design of turning tools.)

1. A labor-saving turning tool bionic design method is characterized by comprising the following steps:

firstly, obtaining a tooth image of a bulb shell;

extracting outline point cloud data of the teeth of the bulb from the tooth image of the bulb by an image processing technology, and dividing the extracted outline point cloud data into two parts of inner outline point cloud data and outer outline point cloud data by data processing;

fitting the point cloud data of the inner contour to obtain a fitting curve equation of the inner contour of the tooth of the cap shell, and fitting the point cloud data of the outer contour to obtain a fitting curve equation of the outer contour of the tooth of the cap shell;

designing a front tool face of the turning tool according to the inner contour fitting curve, and designing a rear tool face of the turning tool according to the outer contour fitting curve;

the cross section shape of the front tool face of the designed turning tool has the characteristic of fitting curve of the inner contour of the cap shell teeth, and the cross section shape of the rear tool face of the designed turning tool has the characteristic of fitting curve of the outer contour of the cap shell teeth.

2. The labor-saving turning tool bionic design method according to claim 1, characterized in that the specific process of the first step is as follows:

geometric images of the cap shell teeth were obtained by optical microscopy.

3. The labor-saving turning tool bionic design method according to claim 2, characterized in that the fitting in the third step is performed by a polynomial fitting method.

4. The bionic design method for the labor-saving turning tool as claimed in claim 3, wherein the fitting curve equation of the inner contour of the tooth of the cap shell is as follows:

y₁＝-7.3×10^-10x₁ ⁵+5.8×10^-7x₁ ⁴-1.5×10^-4x₁ ³+0.013x₁ ²-0.97x₁-1.3 (1)

wherein x is₁Is the X-axis coordinate value, y, of the contour fitting curve of the tooth of the cap shell in the projection plane₁Is the Y-axis coordinate value of the contour fitting curve of the tooth of the cap shell in the projection plane.

5. The labor-saving turning tool bionic design method according to claim 4, wherein the fitting curve equation of the outer contour of the tooth of the cap shell is as follows:

y₂＝2.2×10^-11x₂ ⁵-2.8×10^-8x₂ ⁴+1.2×10^-5x₂ ³-0.0033x₂ ²+0.075x₂+4 (2)

wherein x is₂Is the X-axis coordinate value, y, of the fitting curve of the outer contour of the projection plane of the tooth of the cap shell₂Is the tooth of the cap shellAnd Y-axis coordinate value of the shadow plane outer contour fitting curve.

6. The labor-saving turning tool bionic design method according to claim 5, characterized in that the process of the second step is realized by matlab software.

Technical Field

The invention belongs to the technical field of combination of mechanical metal cutting and engineering bionics, and particularly relates to a labor-saving turning tool bionic design method based on geometric characteristics of a cap shell tooth.

Background

Turning is a common machining method in the field of machinery, while a turning tool is a tool used for turning, the shape of a cutting edge of a tool affects the cutting efficiency of the tool, and the shape of a flank face of the tool affects the quality of a machined surface and the service life of the tool. Because the cutting edge curve of traditional cutter mostly all is the linear type, and the cutter plane is mostly the plane, consequently, the cutting efficiency of traditional cutter is low, the cutting load is big, life is short. Therefore, how to optimize the geometric shape of the turning tool, reduce the cutting force, improve the cutting efficiency and prolong the service life is one of the key problems of the turning tool design.

With the advent of bionics, researchers found that in nature, biological teeth or toes have excellent biological morphology, with sharp external structures capable of cutting objects of greater hardness, which provides a reference structure for the design of turning tools.

Disclosure of Invention

The invention aims to provide a labor-saving turning tool bionic design method for solving the problems of low cutting efficiency and large cutting load of the traditional tool.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a labor-saving turning tool bionic design method specifically comprises the following steps:

firstly, obtaining a tooth image of a bulb shell;

extracting outline point cloud data of the teeth of the bulb from the tooth image of the bulb, and dividing the extracted outline point cloud data into two parts, namely inner outline point cloud data and outer outline point cloud data;

fitting the point cloud data of the inner contour to obtain a fitting curve equation of the inner contour of the tooth of the cap shell, and fitting the point cloud data of the outer contour to obtain a fitting curve equation of the outer contour of the tooth of the cap shell;

designing a front tool face of the turning tool according to the inner contour fitting curve, and designing a rear tool face of the turning tool according to the outer contour fitting curve;

the cross section shape of the front tool face of the designed turning tool has the characteristic of fitting curve of the inner contour of the cap shell teeth, and the cross section shape of the rear tool face of the designed turning tool has the characteristic of fitting curve of the outer contour of the cap shell teeth.

Further, the specific process of the first step is as follows:

geometric images of the cap shell teeth were obtained by optical microscopy.

Further, the fitting in the third step is performed by a polynomial fitting method.

Further, the interior contour fitting curve equation of the cap shell teeth is as follows:

y₁＝-7.3×10^-10x₁ ⁵+5.8×10^-7x₁ ⁴-1.5×10^-4x₁ ³+0.013x₁ ²-0.97x₁-1.3 (1)

wherein x is₁Is the X-axis coordinate value, y, of the contour fitting curve of the tooth of the cap shell in the projection plane₁Is the Y-axis coordinate value of the contour fitting curve of the tooth of the cap shell in the projection plane.

Further, the fitting curve equation of the outer contour of the tooth of the cap shell is as follows:

y₂＝2.2×10^-11x₂ ⁵-2.8×10^-8x₂ ⁴+1.2×10^-5x₂ ³-0.0033x₂ ²+0.075x₂+4 (2)

wherein x is₂Is the X-axis coordinate value, y, of the fitting curve of the outer contour of the projection plane of the tooth of the cap shell₂Is the Y-axis coordinate value of the fitting curve of the outer contour of the projection plane of the tooth of the cap shell.

The method comprises the steps of projecting the tooth tips of the cap shells onto a plane through a microscope, and establishing an XOY coordinate system on the projection plane, wherein the XOY coordinate system takes the tooth tips of the cap shells as a coordinate origin, the horizontal direction is an X axis, and the vertical direction is a Y axis.

Furthermore, the process of the second step is realized by matlab software.

The invention has the beneficial effects that: the invention provides a labor-saving turning tool bionic design method, and from the viewpoint of bionics, a cap shell tooth is found to have good cutting performance. The lathe tool geometry is optimized by mimicking the geometry of a calotte tooth. The front knife face of the optimized and finished cutter is a variable curvature curved surface, and the front angle of the cutter changes along with the curvature, so that the cutter is always in a variable front angle cutting state in the cutting process, cuttings are enabled to be bent, the cutter is separated from the cutter and broken, the contact length between the cutter and the cuttings is reduced, the friction resistance between the cutter and the cuttings is further reduced, the cutting load is reduced, the cutting force of the lathe tool in the working process is reduced, and the cutting efficiency is improved.

Drawings

FIG. 1 is a diagram of a point cloud of a tooth of a bulb;

FIG. 2 is a graph of a contour fit of the inside of a tooth of a calotte;

FIG. 3 is a graph of a fit of the outer contour of a tooth of a cap shell;

FIG. 4 is a two-dimensional block diagram of a design turning tool;

FIG. 5 is a schematic diagram of a three-dimensional model of a design turning tool;

FIG. 6 is a schematic cross-sectional view of a design turning tool A-A;

FIG. 7 is a comparison graph of cutting forces of a design turning tool and a common turning tool;

in the figure: 1. the cutting tool comprises a front tool face, a rear tool face, a cutting edge, a cutting groove and a cutting edge.

Detailed Description

In a first specific embodiment, the bionic design method for the labor-saving turning tool specifically comprises the following steps:

firstly, obtaining a tooth image of a bulb shell;

extracting outline point cloud data of the teeth of the bulb from the tooth image of the bulb by an image processing technology, and dividing the extracted outline point cloud data into two parts of inner outline point cloud data and outer outline point cloud data by data processing;

fitting the point cloud data of the inner contour to obtain a fitting curve equation of the inner contour of the tooth of the cap shell, and fitting the point cloud data of the outer contour to obtain a fitting curve equation of the outer contour of the tooth of the cap shell;

designing a front tool face of the turning tool according to the inner contour fitting curve, and designing a rear tool face of the turning tool according to the outer contour fitting curve;

the cross section shape of the front tool face of the designed turning tool has the characteristic of fitting curve of the inner contour of the cap shell teeth, and the cross section shape of the rear tool face of the designed turning tool has the characteristic of fitting curve of the outer contour of the cap shell teeth.

The cap shellfish belongs to mollusk, gastropoda, and is flat, and is adsorbed on rock at ordinary times, and sea weed and seaweed are used as food, and an annular low-lying area is chiseled on the hard rock through teeth to serve as habitat. It can be seen that the calotte teeth have very good cutting properties, which are closely related to the geometry of their teeth. Therefore, the geometric shape of the cap shell tooth is applied to the design of the turning tool, and the cutting tool has important significance for reducing cutting force, improving cutting efficiency and prolonging service life.

The second embodiment, which is different from the first embodiment, is: the specific process of the step one is as follows:

geometric images of the cap shell teeth were obtained by optical microscopy.

Other steps and parameters are the same as those in the first embodiment.

The third embodiment, which is different from the first or second embodiment, is that: the fitting method in the third step is a polynomial fitting method.

Other steps and parameters are the same as those in the first or second embodiment.

The fourth embodiment and the differences between this embodiment and the first to the third embodiments are: the interior contour fitting curve equation of the cap shell teeth is as follows:

y₁＝-7.3×10^-10x₁ ⁵+5.8×10^-7x₁ ⁴-1.5×10^-4x₁ ³+0.013x₁ ²-0.97x₁-1.3 (1)

wherein x is₁Is the X-axis coordinate value, y, of the contour fitting curve of the tooth of the cap shell in the projection plane₁Is the Y-axis coordinate value of the contour fitting curve of the tooth of the cap shell in the projection plane.

Other steps and parameters are the same as those in one of the first to third embodiments.

The fifth embodiment is different from the first to the fourth embodiments in that: the fitting curve equation of the outer contour of the tooth of the cap shell is as follows:

y₂＝2.2×10^-11x₂ ⁵-2.8×10^-8x₂ ⁴+1.2×10^-5x₂ ³-0.0033x₂ ²+0.075x₂+4 (2)

wherein x is₂Is the X-axis coordinate value, y, of the fitting curve of the outer contour of the projection plane of the tooth of the cap shell₂Is the Y-axis coordinate value of the fitting curve of the outer contour of the projection plane of the tooth of the cap shell.

The method comprises the steps of projecting the tooth tips of the cap shells onto a plane through a microscope, and establishing an XOY coordinate system on the projection plane, wherein the XOY coordinate system takes the tooth tips of the cap shells as a coordinate origin, the horizontal direction is an X axis, and the vertical direction is a Y axis.

Other steps and parameters are the same as in one of the first to fourth embodiments.

Sixth embodiment, the difference between this embodiment and one of the first to fifth embodiments, is: and the process of the second step is realized by matlab software.

Other steps and parameters are the same as those in one of the first to fifth embodiments.

Example 1: and obtaining an inner contour fitting curve equation of the capped shell teeth and an outer contour fitting curve equation of the capped shell teeth according to the capped shell tooth point cloud data diagram of the fig. 1 and the capped shell tooth inner contour fitting curve diagram of the fig. 2 and the capped shell tooth outer contour fitting curve diagram of the fig. 3.

Designing the turning tool of fig. 4 according to the inner contour graph of the calotte tooth of fig. 2 and the outer contour graph of the calotte tooth of fig. 3, wherein the turning tool comprises a front tool surface 1, a rear tool surface 2 and a cutting edge 3 between the front tool surface 1 and the rear tool surface 2;

obtaining the turning tool three-dimensional model schematic diagram of fig. 5 according to the turning tool two-dimensional structure diagram of fig. 4; and a chip breaker groove 4 is arranged on the front tool face of the turning tool.

And obtaining a section schematic diagram of the turning tool A-A of fig. 6 according to the turning tool three-dimensional model schematic diagram of fig. 5, wherein the front tool face of the turning tool has the inner contour curve characteristic of the cap shell teeth, and the rear tool face of the turning tool has the outer contour curve characteristic of the cap shell teeth.

Carrying out a turning simulation experiment by using the turning tool shown in the figure 5, and comparing the turning tool with a common turning tool to obtain a cutting force comparison diagram of the designed turning tool and the common turning tool shown in the figure 7; as shown in fig. 7, the turning tool of the present invention can reduce the cutting force. Through analysis, the following results are found: the front cutter face of the designed turning tool is a variable curvature curved surface, and the front angle of the turning tool changes along with the curvature, so that the turning tool is always in a 'variable front angle' cutting state in the cutting process, cuttings are enabled to be bent, the turning tool is separated from the turning tool and is broken, the contact length between the turning tool and the cuttings is reduced, the friction resistance between the turning tool and the cuttings is reduced, and the cutting force is reduced.

The above-described calculation examples of the present invention are merely to explain the calculation model and the calculation flow of the present invention in detail, and are not intended to limit the embodiments of the present invention. It will be apparent to those skilled in the art that other variations and modifications of the present invention can be made based on the above description, and it is not intended to be exhaustive or to limit the invention to the precise form disclosed, and all such modifications and variations are possible and contemplated as falling within the scope of the invention.