Lathe Cutter Research Articles

Influence of end cutting edge angle of a multi-point lathe cutter on the thread profile accuracy. Theoretical investigation

Modern manufacturers of tools for turning threads make them with a non-zero value of the side rake angle of the cutting edge, which significantly increases their efficiency. The value of this angle is approximately equal to the thread lead angle. However, today there is a lack of theoretical research that would provide an algorithm for calculating the effect of the side rake angle of the cutting edge on one of the indicators of the thread accuracy - the accuracy of the pitch diameter. Its effect is particularly noticeable for thread with a large pitch and relatively small diameter - such as drill string tool-joint thread. Theoretical studies show the possibility of ensuring the required accuracy without changing the profile of the cutting edge of the lathe tool.

МОДЕЛИРОВАНИЕ ТЕМПЕРАТУРНОГО РАСПРЕДЕЛЕНИЯ НА ПЕРЕДНЕЙ ПОВЕРХНОСТИ ТОКАРНОГО РЕЗЦА С УЧЁТОМ ГЕОМЕТРИЧЕСКИХ ПАРАМЕТРОВ ЗОНЫ ВТОРИЧНЫХ ПЛАСТИЧЕСКИХ ДЕФОРМАЦИЙ

The study objective: modeling of the temperature distribution along the front surface of the lathe cutter for a given moment of the cutting system evolution.
 The problem to which the paper is devoted. To evaluate the influence of the geometric parameters of the secondary plastic zone of on the characteristics of the temperature distribution for the front surface of the lathe cutter. 
 Research methods. Geometric parameters of the plastically deformed layer are defined by digital modeling of contact processes by the finite element method. Some initial data for computer modeling and subsequent verification of its results are carried out on the basis of a full-scale experiment with longitudinal turning of a work piece made of stainless steel 12X18H9T with a T15K6 solid-alloy plate.
 The novelty of the work. Prediction of the temperature on the cutter front surface for a given moment of the cutting system evolution based on a scientific approach of using hydrodynamic analogies to the evaluation of deformation processes in the machined material and combined data of a full-scale and digital experiment. 
 The study results. By means of a digital experiment, the boundaries of the secondary plastic zone in the chip are determined, then a temperature distribution curve is made on the cutter front surface in two variants: for variable and for a constant average thickness of the deformed layer. It is found that the average value of the contact temperature in both cases differs slightly and agrees well with the results of the full-scale experiment. The difference between the maximum temperature values is significant: with a variable layer thickness, the calculated temperature is 11% lower than for the variant with a constant value of this parameter. 
 Conclusions: to calculate the average temperature in the secondary plastic zone, the average value of the deformed layer thickness can be used. In the case of solving problems related to determining the maximum temperature in the cutting zone, it is advisable to take into account the change in the thickness of the plastically deformed layer in the chip along the cutter front surface.

Modeling of the temperature field on the rake surface of the lathe cutter taking into account the evolution of cutting forces

This paper is devoted to modeling the temperature field on the rake surface of the hard alloy lathe cutter when turning the work piece from structural steel 30 for a given value of the operating time of the cutting system. The assessment of the thermal state is made taking into account the change in cutting forces during machining. To do this, a model of the evolution of the radial and axial components of the cutting force was built, taking into account its growth in time and the influence of irregular kinematic vibrational perturbations. The calculation of the average temperature values for each section of the rake surface was made on the basis of the scientific approach described earlier, according to which the heating of the contact occurs due to the viscous dissipation of the friction energy in the surface plastically deformed micro layers of the chip. The calculation of the temperature values along the rake surface was carried out by the finite element method on a solid-state model of a fragment of the cutting part of the tool, as a result of which temperature values for the control planes were obtained. The results of digital modeling demonstrate a good correspondence of the calculated temperature values to the experimental data obtained by the semi artificial thermocouple method. The error of modeling the temperature field without taking into account heat exchange with the environment was 7.7-8.6%.

GEOMETRIC PARAMETERS OF A PEAKLESS CUTTING TOOL IN THE INSTRUMENTAL COORDINATE SYSTEM

Processing of external surfaces with turning tools is the most common in the total mass of tools, and occupies a special place in the technological process of manufacturing machine parts. The issues of increasing productivity, accuracy and reliability of the processing process have always been and remain relevant and effective for metalworking. The aim of the study is to improve the quality of processing of external cylindrical surfaces with the development of a new processing method and the design of a peakless turning through-hole cutter. The idea of the work is to develop a new design of a lathe cutter for finishing and a new processing method. The analysis of methods and methods of processing external cylindrical surfaces, parameters of the cut layer during cutting, geometry and designs of turning cutting tools, led to the development of a new metal-cutting tool – a peakless turning cutting tool for finishing. The new design improves cutting conditions and minimizes the impact of adverse factors accompanying the cutting process. Thus, a pass-through peakless cutter has one cutting edge, is simpler due to the absence of an auxiliary back surface and top, has less complexity of manufacturing and sharpening, and therefore requires less operating costs.

DEVELOPMENT OF THE DESIGN OF A PEAKLESS ROTARY CUTTING TOOL

Processing of external surfaces with turning tools is the most common in the total mass of tools, and occupies a special place in the technological process of manufacturing machine parts. The issues of increasing productivity, accuracy and reliability of the processing process have always been and remain relevant and effective for metalworking. The aim of the study is to improve the quality of processing of external cylindrical surfaces with the development of a new processing method and the design of a peakless turning through-hole cutter. The idea of the work is to develop a new design of a lathe cutter for finishing and a new processing method. The analysis of methods and methods of processing external cylindrical surfaces, parameters of the cut layer during cutting, geometry and designs of turning cutting tools, led to the development of a new metal-cutting tool - a peakless turning cutting tool for finishing. The new design improves cutting conditions and minimizes the impact of adverse factors accompanying the cutting process. Thus, a pass-through peakless cutter has one cutting edge, is simpler due to the absence of an auxiliary back surface and top, has less complexity of manufacturing and sharpening, and therefore requires less operating costs.

Selecting the Shape of the Insert in a Lathe Cutter

Attention focuses on the selection of a removable polyhedral insert with recommended geometry of the cutting element, when the tool material meets the requirements of intermittent cutting. Shaping of the cutter’s front surface to intensify machining is also considered.

Improving the turning process efficiency for mortar pump cylinder liner

The results of a scientific study related to improving the efficiency of turning process for mortar pump cylinder liner are presented. A literary analysis of the issue of turning optimization is carried out. Professor Larin's criterion is applied. It provides the longest cutting path, that is, the least cost of the cutting tool when machining a batch of products. Precast lathe cutter equipped with a non-grinding plate of rhombic shape of metal-ceramic hard alloy T15K6 is used as a cutting tool

Adaptive Lathe Tools with Modified Geometry

A design is proposed for the attachment of a replaceable polyhedral insert in the housing of a pass-through lathe cutter with two fixed positions of the insert. This design permits modification of the tool geometry.

Influence of the handle design on a composite lathe cutter

In a composite lathe cutter, the influence of the handle design on the rigidity, temperature propagation, and damping of vibrations in cutting is analyzed. Metal cutters with horizontal holes in a checkerboard pattern and without such holes are considered. Software based on the finite-element method is used in the calculations.

A new pass-through lathe cutter

A new pass-through lathe cutter is described. Its cutting edge is formed by primary and secondary cutters so as to improve cutting and shaping.

Automatic Reasoning for Defining Lathe Operations for Mill-Turn Parts: A Tolerance Based Approach

With the increase in computer-controlled hybrid machining (e.g., mill-turn machining), one needs to discern what features of a part are created during turning (i.e., with a lathe cutter) versus those created by milling. Given a generic part, it is desirable to extract the turnable and nonturnable features in order to obtain feasible machining plans. A novel approach for automating this division and for defining the resulting turning operations in a hybrid process is proposed in this paper. Given a mill-turn part, the algorithm first identifies the dominant rotational-axis in order to quickly generate the axisymmetric “as-lathed” model. This model is then subtracted from the original part to isolate the nonturnable features. Next, the as-lathed model is translated to a label-rich graph, which is fed into a grammar reasoning algorithm to produce feasible turning sequences. During the turning process planning, the knowledge encapsulated in the design tolerances is used to guide the generation of feasible turning sequences. Two case studies are provided to explain the details of our algorithm. One of the suggested turning plans is compared with a manually proposed plan from an expert machinist and the results show the optimality of our plan in satisfying the prescribed tolerances.

Temperature fields of a composite lathe cutter with specialized components

1016 A deficiency of traditional lathe cutters is that the wear occurs at a local point on the tip of the cutting blade. In sharpening the cutter, not only the worn edge is removed but also the unworn and still perfectly func� tional lateral cutting edge. The various measures adopted to address this problem have their own advan� tages and disadvantages, which determine the scale of their practical use.

Analysis of Cutter Offset Function in NC Lathe and its Applications

The concept and usage of cutter offset compensation was introduced, and the cutter wear compensation and cutter radius compensation were calculated. The processing error produced by tool corner radius was analyzed, and the function, application occasion and usage of radius compensation in CNC lathe cutter is discussed, which has special significance for the accurate machining. The examples are given to illustrate how to using methods and skills in NC turning programming reasonably.

Pass-through lathe cutter with independent cutting systems

The design of a pass-through lathe cutter with independent cutting systems is considered. The cutter is based on a composite design: one tool has lateral cutting edges; the other has a front cutting edge. The possibility of harmonizing the regrinding of the two tools is analyzed.

Study on Compliant Control by Cutter Radius Compensating for Rotating Curved Surfaces Polishing on NC Lathes

. Lots of new automatic polishing methods and equipments have been developed to solve the problem of low efficiency and quality in the traditional handwork curved surfaces polishing. However, these methods and equipments are complex and difficult to be applied in the industrial production. This paper proposes a new technology of rotate surface compliant polishing based on NC lathe cutter radius compensation. An efficient and compact rotate surfaces compliant polishing system is developed, which consists of a NC lathe, flexible polishing tool, workpiece, fixture and also the automatic programming software MASTERCAM. The polishing tool-path and NC code can be created in MASTERCAM. The value of the cutter radius compensation can also be set in NC code, so that the rotated surfaces can be polished by a traditional NC lathe. Experiment of polishing the aluminum sphere workpiece is taken, and the satisfying surface quality is achieved.