| In the daily production and life, the processing of metal materials, including aluminum metal, need to cut, cut off and other mechanical processes. Among lots of cutting methods, mechanical cutting plays an important role in the metal industry,because of its high adaptability, low cost and high efficiency. As a mechanical cutting tool, circular saw blade has high working efficiencies and can reduce waste of raw materials as well as secondary processing. So it is widely used in many areas including the aluminum industry. However, in the sawing process, traditional blades used to make successive shocks on the cutting objects to make them rupture with its rotation and moving. In the meantime, sawteeth continuously extrude and shear the portion of workpiece around them. However, the cutting efficiency is poor and the cutting resistance is higher. In addition, partially sawteeth prone to crack, fracture and wear.Bionics is a new cross discipline, which can provide new research ideas and effective research methods in solving friction wear, cutting efficiency and energy consumption problems of cutting tools for researchers. From its birth to the present,just a few decades, it produced lots of remarkable achievements. The badgers, also known as Eurasian badgers, whose teeth are extremely sharp and hard and even can bite through the military shovel. This paper takes badger canines as the object of research to find out their mechanism of sharp, hard and pierce efficiently by study on structure and mechanical characteristics of them. The results are used as inspiration for the bionic design of saw blade, in order to improve the cutting efficiency of metal cutting and reduce the cutting forces.First of all, the micro-structure, mechanical properties and compositions of badger canines were tested and analysed. As a result, the good mechanical properties of badger canines are related to their unique Outline shape. The three-dimensional solid models of badger teeth were reconstructed with reverse engineering technology. The characteristic curve of badger canine was divided into three sections of piercing,cutting and sliding based on the analysis of structure and pierce mechanism of canine.And they were fitted with the least square method to get thire equation, which were used in the design of circular saw blades, getting bionic saw A, and bionic saw B,bionic saw C. The later were uesed as bionic references.Secondly, the mechanics models of sawing were established. Based on the analysis of sawing process, the theoretical sawing force was calculated. According to thecalculation of sawing force which was tested from the process that the Aluminum rod whose diameter is 30 mm was cut by saw blade(D=180mm), cutting power N=0.728 KW, tangential cutting force Ft= 406.57 N, radial sawing force Fr=100N. This could provide load conditions for static analysis of saw blade. On the basis of load conditions, the finite element model of saw cutting was established. Then the mechanical properties and structural characteristics was compared between bionic blades and common blades. As a result, the bionic saw blade A has the advantages of less deformation and stress, compared with the others under the same force condition.Finally, speed of saw blade, feed rate of workpiece, diameter of the saw and diameter of workpiece are selected as experimental factors, torque and tension generated in sawing process as experiment index. The sawing forces of bionic saw blades were analyzed with orthogonal table of L9(31×23). According to the results, the experimental factors had been selected were significantly correlated with the torque and tension of sawing process and the effects of the factors on the torque and the pulling force of the bionic saw blades were blade speed > the workpiece speed > blade diameter > workpiece diameter. In addition, as a result of analysis on single factor experiments, under the same cutting conditions, the torque value of bionic blade A was respectively reduced by 18.4% and 6.5%, compared with wolf tooth saw blade and the rat tooth saw blade. Moreover, the horizontal force of bionic saw blade A was respectively reduced by about 27.7% and 10%, compared with wolf tooth saw blade and the rat tooth saw blade. As far as the cutting quality was concerned, the incision of bionic blade A was smoother and neater. This is because that the bionic curves were used to the design of sawteeth profile of saw blade A, which could increase the width along the circumference and rake angle of sawteeth. It not only could improve the sawtooth stiffness, but also could reduce the cutting resistance of saw blade during the sawing process.In summary, the idea and technology of bionic design has been applied to the design of blade, aiming at solving the existing problem of poor sawing performance and high cutting resistance of circular saw blades. As a result, bionic saw blade A is invented, based on badger canines. And it indeed can reduce the sawing forces and improve the cut quality, which may provide a reference for the design and popularization of saw blade of the high performance. |
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