System for measuring thermal error of precise numerically-controlled machine tool and compensating temperature

Abstract

The invention discloses a system for measuring the thermal error of a precise numerically-controlled machine tool and compensating temperature, and belongs to the technical field of numerically-controlled machine tool temperature compensation. The system comprises a thermal error measuring system, a programmable logic controller, a numerical control unit, and a temperature-compensating system. The thermal error measuring system comprises a plurality of inductive displacement sensors, a plurality of temperature sensors, and a signal filter. The temperature-compensating system comprises a temperature-compensating unit, a position-adjusting module, and a data-computing unit. The numerical control unit comprises a correction module, a temperate compensation computing module, a numerically-controlled machine tool interpolation module, a temperature-acquiring module, and a numerically-controlled machine tool position control module. The temperate compensation computing module computes the temperature compensation value of a corresponding shaft of the machine tool at a certain time. The numerically-controlled machine tool position control module enables the shaft to backwardly move if the temperature compensation value is a positive value, or enables the shaft to forwardly move if the temperature compensation value is a negative value. The system is high in measurement precision and may simultaneously acquire the thermal displacement and the temperature difference of the numerically-controlled machine tool.

Description

technical field [0001] The invention relates to a thermal error measurement and temperature compensation system of a numerical control machine tool, in particular to a thermal error measurement and temperature compensation system of a precision numerical control machine tool, belonging to the technical field of temperature compensation of a numerical control machine tool. Background technique [0002] Machine tool (English name: machine tool) refers to a machine that manufactures a machine, also known as a machine tool or a machine tool. It is customarily referred to as a machine tool. It is generally divided into metal cutting machine tools, forging machine tools, and woodworking machine tools. The method of processing mechanical parts in modern machinery manufacturing Many: In addition to cutting processing, there are also casting, forging, welding, stamping, extrusion, etc., but all parts with high precision requirements and fine surface roughness requirements generally ne...

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Problems solved by technology

[0004] At present, the basic parts of guide rails such as the bed, column, and carriage of CNC machine tools, and the transmission components such as ball screws are all made of metal materials. An additional error will be generated to the position of the movement axis of the machine tool, which will directly affect the positioning accuracy of the machine tool, thereby affecting the machining accuracy of the workpiece. For CNC machine tools used in ordinary workshop environmental conditions, especially large-scale machine tools with relatively long strokes, the thermal expansion coefficient is more important. It cannot be ignored. For example, for a feed shaft with a stroke of 5 meters, the thermal expansion coefficient of the metal material is 10ppm (10μm / per lm per l degree). "50μm, the influence of the daily temperature difference and the temperature difference between winter and summer can be imagined, but the existing technology cannot meet the thermal error measurement of CNC machine tools and obtain the function of thermal displacement and temperature value at the same time. Manufactured or used under normal conditions, in order to ensure high positioning accuracy and machining accuracy for CNC machine tools used under ordinary conditions, measures must be taken to eliminate thermal displacement and temperature errors

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