Influence of Wheel Blunting on the Machining Precision in CNC Plunge Grinding: Digital Twin Analysis

Russian Engineering Research - The machining precision in grinding a flexible shaft by sharp and blunt wheels is compared for a CNC system with a specified cycle of radial supply velocities. To...     

Influence of Instrument Position in Active Monitoring on the Accuracy and Productivity of CNC Plunge Grinding

Russian Engineering Research - In active monitoring, the position of the instrument may influence the accuracy and productivity of machining. This influence is considered in the present work for...     

Influence of Variable Machining Conditions on the Precision in CNC Plunge Grinding: Predictive Analysis by a Digital Twin

Russian Engineering Research - A system for predicting the machining error for a batch of parts in CNC wheel grinding is described; the system takes the influence of technological variables into...     

Optimal internal grinding cycles in multidimensional control-parameter space

A method is proposed for the design of optimal internal grinding cycles in multidimensional control- parameter space, under numerous technological constraints. This method is based on stepwise modeling of metal removal in terms of specified machining properties, with allowance for elastic deformation and the cutting kinematics. Optimization is based on dynamic programming, which permits any number of technological constraints to be taken into account and is not sensitive to the type of mathematical models employed or the constraints on the target function.     

Influence of Dynamic Displacement of the Machining System on the Accuracy of Plunge Grinding

Russian Engineering Research - The proposed dynamic model of cutting-depth formation establishes a relation between factors such as the margin removed, the elastic deformation and dynamic...     

Optimal machining cycles for numerically controlled metal-cutting machines

The design of optimal automatic machining cycles for numerically controlled metal-cutting machines is considered, in theoretical terms. Dynamic programming permits the optimization of an unlimited number of control parameters for all the machining operations in numerically controlled metal-cutting machines.     

Optimizing the Internal-Grinding Cycle at the Insertion Stage

In internal grinding with axial feed, each double pass begins with insertion of the grinding wheel in the workpiece in the reversing zone, by means of a radial insertion feed; the axial feed in this process is zero. Therefore, at that stage, the cutting conditions are fundamentally different than in machining the remainder of the hole, when the axial feed is nonzero. As a result, in the reversing zone, the quality of machining is significantly different from that for the remainder of the surface. A methodology is considered for optimization of the parameters at wheel insertion, for the example of internal grinding with axial tool feed. Dynamic programming is used for optimization.     

Cutting Forces in Internal Grinding

Models of the cutting force in various types of grinding may be based on the fundamental laws regarding local plastic deformation of metal by the wheel’s abrasive grains and also the kinematics of cutting in the grinding conditions. The models take account of the cutting conditions and the geometric parameters of the wheel–workpiece contact zone.     

Modeling of metal removal during an internal grinding in view of kinematics cutting features

A new model of the metal removal in internal grinding permits calculation of the margin actually removed, the internal radius, the time for complete removal of the margin, and other parameters. In the model, the metal removal is determined with specified machining parameters; elastic deformation and the cutting kinematics are taken into account. The calculation is based on the model of the cutting force in internal grinding, which covers most of the factors affecting the cutting force (such as changes in the programmed and actual radial supply, the mechanical properties of the workpiece, the geometry of the wheel–workpiece contact zone, the wheel characteristics, and the blunting of the abrasive grains). Types of wheel–workpiece contact with inclination of the wheel axis on account of elastic deformation of the system are noted.     

The problem resolution of designing of cycles in the conditions of modern automated production

The design of machining cycles in automated production entails the development of a theory regarding the selection of optimal automatic cycles for numerically controlled metal-cutting machines. This theory is based on dynamic programming and permits optimization of an unlimited number of control parameters for all types of machining operations.