Numerical control machine tool main shaft unit static stiffness testing apparatus and test method

Abstract

The invention discloses a numerical control machine tool main shaft unit static stiffness testing apparatus and a test method. Three groups of loading apparatuses that have the same structure for clamping the examination rod of the numerical control machine tool main shaft and applying force to the examination rod are set on a pedestal; the examination rod has a capacitance displacement sensor; the main bodies of the three groups of loading apparatuses are set in the pedestal respectively; among the three groups of loading apparatuses, the push rod at the front end for clamping the examination rod extends outside the pedestal, and the push rods of the three groups of loading apparatuses extend out of the pedestal along X direction, Y direction and Z direction respectively; a voltage amplifier electrically connected to the three groups of loading apparatus and an NI data collection card respectively electrically connected to the voltage amplifier, the capacitance displacement sensor and the three groups of loading apparatuses are set on the pedestal; and the voltage amplifier is connected to an outside power supply. By means of the powerful storage and operation function of the computer, the collected displacement and force data are used for curve fitting by the computer, and a force-displacement static stiffness curve is drawn, therefore, the test method is suitable for static stiffness test for various vertical or horizontal numerical control machine tool main shaft units.

Description

technical field [0001] The invention relates to a performance testing system of a numerically controlled machine tool. In particular, it relates to a static stiffness test device and a test method of a spindle unit of a CNC machine tool. Background technique [0002] The static stiffness of the spindle unit of a CNC machine tool refers to the ability of the spindle unit to resist deformation under the action of cutting force. Usually, the static stiffness of the spindle is represented by the force applied in the displacement direction when the front end of the spindle generates a unit displacement, as the evaluation of CNC machine tools. An important indicator of the quality of the whole machine is also an important indicator of the design of the CNC machine tool spindle. It can not only reflect the vibration resistance and stability of the spindle unit, but also the static performance of the CNC machine tool spindle will affect its dynamic characteristics. The static defor...

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Problems solved by technology

[0003] The static stiffness test system of CNC machine tool spindle unit mainly includes cutting force simulation loading device, loading force detection, spindle force deformation detection, data acquisition and processing, spindle static stiffness curve display and other basic theory and experimental technology research work. Some scholars have conducted relevant research, and there are also many research results and literature publications on the static stiffness test methods of ordinary machine tools and CNC machine tools. However, in these results, most of the test methods developed for the static stiffness of CNC machine tools use Hydraulic or spiral loading methods, and can only be measured in a single direction. There are not many test systems that load and measure radial and axial simultaneously. After testing in one direction, these test devices need to be reinstalled and debugged before testing the other. This obviously brings inconvenience to the actual test work and has great limitations. Although other research results can measure the static stiffness in three directions at the same time, most of the test systems are hydraulic or screw loading methods, which are prone to leakage or The loading force is not enough, and the research of a large number of scholars only stays in the conception or experiment of the scheme

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