Method for predicting metal cutting tool nose dead zone morphology through considering metal slippage

Abstract

The invention relates to a method for calculating the dead zone morphology by using the metal slip line theory complete theory. The method comprises the following steps: firstly, determining the radius of a blunt circle of a tool nose of a used tool through measurement; and then front angles and friction angles of all positions on the blunt circle of the tool nose need to be calculated, and then shearing angles of all the positions, namely the shearing direction of metal, are obtained. And obtaining the friction coefficient of each position by using the friction angle, and further solving theincluded angle between the metal slip line and the plastic boundary, namely the included angle between the boundary line of the dead zone and the blunt circle of the tool nose; the metal shearing direction is collinear with the boundary line of the dead zone, so that the positions of the vertexes S1 and S2 of the dead zone on the blunt circle of the tool nose can be solved. And after judging whether the vertexes S1 and S2 exist or not, deriving and solving the position of the vertex S3 through a geometrical relationship by utilizing the positions of the vertexes S1 and S2 and the included angle between the boundary line of the dead zone at the two points and the blunt circle of the tool nose, so as to completely determine the morphology of the dead zone of the tool nose. According to the method, the complete morphology of the dead zone of the tool nose can be predicted through complete theoretical calculation without any factors needing to be given manually.

Description

technical field [0001] The invention relates to a method for predicting metal flow at the tip of a cutting tool, in particular to a method for predicting the shape of a dead zone in consideration of the blunt roundness of the tip of the tool to form a dead zone formed by metal stagnation at the tip of the tool. Background technique [0002] In modeling metal cutting, it is common to consider the tip of a tool to be perfectly sharp. However, in practice, there will always be a blunt circle at the tip of the tool, especially for micro-cutting processes or when using passivated tools, the cutting amount of the cutter tooth is equivalent to the radius of the blunt circle of the tool tip, and the influence of the blunt circle cannot be ignored. At this time, the metal will form a stagnation near the blade, forming a dead zone. The flow velocity of the metal inside and outside the dead zone is different, that is, there is a flow velocity discontinuity in the normal direction of t...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the problem that the existing methods need to artificially select part of the content when modeling the dead zone of the tool tip, the present invention provides a method for completely theoretically calculating the shape of the dead zone using the metal slip line theory

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