Abstract: A prediction method of part surface roughness and tool wear based on multi-task learning belong to the file of machining technology. Firstly, the vibration signals in the machining process are collected; next, the part surface roughness and tool wear are measured, and the measured results are corresponding to the vibration signals respectively; secondly, the samples are expanded, the features are extracted and normalized; then, a multi-task prediction model based on deep belief networks (DBN) is constructed, and the part surface roughness and tool wear are taken as the output of the model, and the features are extracted as the input to establish the multi-task DBN prediction model; finally, the vibration signals are input into the multi-task prediction model to predict the surface roughness and tool wear.

Abstract: A toolholder matched with the internal jet cooling spindle for cryogenic coolant is mainly composed of a hollow toolholder body, a high-performance thermal insulation structure and a bidirectional sealing structure. They can guide the cryogenic coolant from the spindle to the internal cooling channel of cutting tool and realize the cryogenic thermal insulation and dynamic sealing. The high-performance thermal insulation structure inside the toolholder employs the material with a low thermal conductivity and a low linear expansion coefficient to restrain the low temperature impact of cryogenic coolant on the toolholder and spindle, to ensure the dimensional accuracy and assembly accuracy of the toolholder. The bidirectional sealing structure in the toolholder uses the ultra-low temperature resistant seal rings to prevent the cryogenic coolant from leaking towards the spindle and the cutting tool, to ensure the stability of the coolant transport.

Abstract: The invention provides a dynamic seal test device for cryogenic fluid medium. The dynamic seal test device includes stator unit, rotor unit, slipway, servo motor unit and sensors. The tested seal is installed inside the stator, and the thermal insulation stator and vacuum rotor together form a dynamic seal test structure. The seals and shaft sleeves can be flexibly replaced, which is beneficial to study the influence of different seal types, structure, and seal land configurations on the sealing performance. The servo motor provides power for the rotor and controls the rotation speed. The device greatly improves the thermal insulation capacity to avoid the gasification for the cryogenic fluid medium induced by the heat transfer from environment so that ensuring the stability of the test device.

Abstract: A prediction method of part surface roughness and tool wear based on multi-task learning belong to the file of machining technology. Firstly, the vibration signals in the machining process are collected; next, the part surface roughness and tool wear are measured, and the measured results are corresponding to the vibration signals respectively; secondly, the samples are expanded, the features are extracted and normalized; then, a multi-task prediction model based on deep belief networks (DBN) is constructed, and the part surface roughness and tool wear are taken as the output of the model, and the features are extracted as the input to establish the multi-task DBN prediction model; finally, the vibration signals are input into the multi-task prediction model to predict the surface roughness and tool wear.

Abstract: The invention provides a tool holder suitable for cryogenic minimum quantity lubrication, which belongs to the technical field of cooling and lubrication of numerical control machine tools. The device comprises a toolholder body, a peripheral static structure, a multilayer sealing structure, a heat insulation structure, and a bearing support structure. The invention solves the problems of insufficient cooling performance in the micro-lubrication technology and insufficient lubrication in the cryogenic cooling machining technology, and integrates the oxygen insulation protection effect of the cryogenic medium, the cooling effect of the cryogenic medium, and the friction reduction and lubrication effect of the micro-lubrication. It has a good processing effect on difficult-to-cut materials.

Abstract: The invention provides a dynamic seal test device for cryogenic fluid medium. The dynamic seal test device includes stator unit, rotor unit, slipway, servo motor unit and sensors. The tested seal is installed inside the stator, and the thermal insulation stator and vacuum rotor together form a dynamic seal test structure. The seals and shaft sleeves can be flexibly replaced, which is beneficial to study the influence of different seal types, structure, and seal land configurations on the sealing performance. The servo motor provides power for the rotor and controls the rotation speed. The device greatly improves the thermal insulation capacity to avoid the gasification for the cryogenic fluid medium induced by the heat transfer from environment so that ensuring the stability of the test device.

Abstract: The invention provides a toolholder matched with the internal jet cooling spindle for cryogenic coolant. The toolholder is mainly composed of a hollow toolholder body, a high-performance thermal insulation structure and a bidirectional sealing structure. They can guide the cryogenic coolant from the spindle to the internal cooling channel of tool and realize the cryogenic thermal insulation and dynamic sealing. The high-performance thermal insulation structure inside the toolholder employs the material with a low thermal conductivity and a low linear expansion coefficient to restrain the low temperature impact of cryogenic coolant on the toolholder and spindle, to ensure the dimensional accuracy and assembly accuracy of the toolholder. The bidirectional sealing structure in the toolholder uses the ultra-low temperature resistant seal rings to prevent the cryogenic coolant from leaking towards the spindle and the tool, to ensure the stability of the coolant transport.

Abstract: The present invention provides a method for determining the real-time thermal deformation attitude of the spindle and it belongs to the technical field of error testing of the CNC machine tools. Firstly, the temperature and the displacement sensors are applied to determine the temperature of the upper and lower surfaces of the spindle box and the radial thermal error of the running spindle, respectively. Then, the thermal variation of the upper and lower surfaces of the spindle box is calculated in accordance with the radial thermal error of the spindle. Then the model for the thermal variation and the temperature of the upper and lower surfaces of the spindle box is established. Finally, the established model is employed to determine the real-time thermal deformation attitude of the spindle, according to the real-time temperatures of the upper and lower surface of the spindle box.