NC Reconstruction of High Accuracy Spheres Grinding

2010 ◽  
Vol 102-104 ◽  
pp. 539-543
Author(s):  
Ying Liang Yu ◽  
Zhi Yi Miao ◽  
Hui Yu
Keyword(s):  
Machine Tool ◽  
High Accuracy ◽  
Rotary Motion ◽  
Grinding Wheel ◽  
Variable Speed ◽  
Large Size ◽  
Linear Instruction ◽  
Grinding Machine ◽  
Application Scope

The design of NC reconstruction of a machine tool and the parameters conversion are elaborated by means of an example of sphere grinding using a common grinding machine which has been reconstructed by special NC technologies. The grinding of a large size sphere is realized by using the linear instruction. The variable speed rotary grinding of a large size sphere is realized by using the arc instruction. The instantaneous compensation of the grinding wheel is realized by using the screw instruction. The function and application scope of NC technology are expanded because of variable speed rotary motion and instantaneous compensation of the grinding wheel.

New Development of Supersonic Surface Grinding Machine Tool with a Linear-Motor-Driven Table System

2016 ◽  
Vol 1136 ◽  
pp. 667-672
Author(s):  
Lu Yang ◽  
Yu Can Fu ◽  
Jiu Hua Xu ◽  
Yong Tao Liu
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
High Performance ◽  
Linear Motor ◽  
Grinding Wheel ◽  
Research Activities ◽  
High Speed Grinding ◽  
Grinding Mechanism ◽  
Speed Up ◽  
Grinding Machine

Ultra-high speed grinding (UHSG) is a significant and promising machining technology in grinding hard-to-cut materials. To find out the aerodynamics of the grinding wheel body when the airflow field has subsonic, transonic, and supersonic speed characteristics and clarify the corresponding influence on the grinding mechanism, the study is conducted to develop a supersonic grinding machine tool that is capable of being operated at extreme wheel speed up to 450 m/s and meanwhile accompanying with high grinding capability. In accordance with the main design objectives, a high performance grinding motorized spindle with maximum rotational speed 36000r/min and maximum power 28kW is developed. The linear motor feed driven system is also exploited to satisfy the requirement of maximum reciprocating speed up to 2m/s. Following plenty of specific design and performance analysis works, a prototype of supersonic grinding machine tool is finally developed. In the end, this paper also puts forward a number of further studies and prospective for the research activities on basis of the developed grinder.

Study on Axial Oil Chamber Design for High Performance Hydrostatic Spindle

2014 ◽  
Vol 701-702 ◽  
pp. 869-873
Author(s):  
Shao Hsien Chen ◽  
Shang Te Chen ◽  
Chien Cheng Hsu
Keyword(s):  
Machine Tool ◽  
High Performance ◽  
Development Trend ◽  
Ball Screw ◽  
Precision Machining ◽  
Large Size ◽  
Chamber Design ◽  
Ultra Precision ◽  
Bearing Stiffness ◽  
Application Scope

Ultra-precision machining and large-size equipments are themostprimary development trend ofcurrentmachine tooland hydrostatic products arekeytechnologiesof ultra-precision machining equipments. However, these equipmentsmostlyprocess miniature components, thus the adopted tools are relatively small and the spindlesare mainlybuilt-in types of HSK32-HSK25 withover30,000r. Some processing equipments are even equipped with hydrostatic or gas-static spindles. The studyextends theaxialoilchamberto radialonesto expand theaction areaofaxialoil pressureand form a closed oil seal edge by combining theradialclearance. Consequently, theaxialbearing stiffnesscan be enhancedtoenlarge the application scope of hydrostatic spindle. The designmodecan enhanceaxialstiffness ofspindle modulesor strengthenthe stiffness of hydrostatic spindlein a ball screw.

scholarly journals Sound Event Detection in Underground Parking Garage Using Convolutional Neural Network

2020 ◽  
Vol 4 (3) ◽  
pp. 20 ◽  
Author(s):  
Giuseppe Ciaburro
Keyword(s):  
Event Detection ◽  
High Accuracy ◽  
Surveillance Systems ◽  
Urban Mobility ◽  
Parking Garage ◽  
Large Size ◽  
Car Crash ◽  
Sound Event ◽  
Parking Management ◽  
Sound Event Detection

Parking is a crucial element in urban mobility management. The availability of parking areas makes it easier to use a service, determining its success. Proper parking management allows economic operators located nearby to increase their business revenue. Underground parking areas during off-peak hours are uncrowded places, where user safety is guaranteed by company overseers. Due to the large size, ensuring adequate surveillance would require many operators to increase the costs of parking fees. To reduce costs, video surveillance systems are used, in which an operator monitors many areas. However, some activities are beyond the control of this technology. In this work, a procedure to identify sound events in an underground garage is developed. The aim of the work is to detect sounds identifying dangerous situations and to activate an automatic alert that draws the attention of surveillance in that area. To do this, the sounds of a parking sector were detected with the use of sound sensors. These sounds were analyzed by a sound detector based on convolutional neural networks. The procedure returned high accuracy in identifying a car crash in an underground parking area.

Calculation of Effective Ground Depth of Cut by Means of Grinding Process Model

2011 ◽  
Vol 496 ◽  
pp. 7-12 ◽  
Author(s):  
Takazo Yamada ◽  
Michael N. Morgan ◽  
Hwa Soo Lee ◽  
Kohichi Miura
Keyword(s):  
Process Model ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Elastic Deformations ◽  
Proposed Model ◽  
Effective Depth ◽  
Grinding Machine

In order to obtain the effective depth of cut on the ground surface, a new grinding process model taking into account thermal expansions of the grinding wheel and the workpiece, elastic deformations of the grinding machine, the grinding wheel and the workpiece and the wheel wear was proposed. Using proposed model, the effective depth of cut was calculated using measured results of the applied depth of cut and the normal grinding force.

scholarly journals Grinding of AISI 4340 steel with interrupted cutting by aluminum oxide grinding wheel

2015 ◽  
Vol 68 (2) ◽  
pp. 229-238
Author(s):  
Hamilton Jose de Mello ◽  
Diego Rafael de Mello ◽  
Eduardo Carlos Bianchi ◽  
Paulo Roberto de Aguiar ◽  
Doriana M. D'Addona
Keyword(s):  
Aluminum Oxide ◽  
Rotation Speed ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Machined Surface ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Grinding Machine ◽  
Aisi 4340

AbstractThere has been a great advance in the grinding process by the development of dressing, lubri-refrigeration and other methods. Nevertheless, all of these advances were gained only for continuous cutting; in other words, the ground workpiece profile remains unchanged. Hence, it becomes necessary to study grinding process using intermittent cutting (grooved workpiece – discontinuous cutting), as little or no knowledge and studies have been developed for this purpose, since there is nothing found in formal literature, except for grooved grinding wheels. During the grinding process, heat generated in the cutting zone is extremely high. Therefore, plenty of cutting fluids are essential to cool not only the workpiece but also the grinding wheel, improving the grinding process. In this paper, grinding trials were performed using a conventional aluminum oxide grinding wheel, testing samples made of AISI 4340 steel quenched and tempered with 2, 6, and 12 grooves. The cylindrical plunge grinding was performed by rotating the workpiece on the grinding wheel. This plunge movement was made at three different speeds. From the obtained results, it can be observed that roughness tended to increase for testing sample with the same number of grooves, as rotation speed increased. Roundness error also tended to increase as the speed rotation process got higher for testing the sample with the same number of grooves. Grinding wheel wear enhanced as rotation speed and number of grooves increased. Power consumed by the grinding machine was inversely proportional to the number of grooves. Subsuperficial microhardness had no significant change. Micrographs reveal an optimal machining operation as there was no significant damage on the machined surface.

scholarly journals Assessment of the safety of use of portable machine tools

2018 ◽  
Vol 189 (3) ◽  
pp. 192-205
Author(s):  
Monika Nowak ◽  
Agnieszka Terelak-Tymczyna
Keyword(s):  
Machine Tool ◽  
Working Conditions ◽  
Machine Tools ◽  
Numerical Control ◽  
Milling Machine ◽  
Safety Issues ◽  
Large Size ◽  
Score Method ◽  
Characteristic Features ◽  
Risk Reducing

The article presents safety issues related to on-site machining with the use of portable machine tools. Their advantage is the possibility of machining elements at places in which they are used. This especially refers to large-size constructions, welded elements and any items whose disassembly is technically difficult. The authors present tasks performed by the operators of portable machining equipment, working conditions, construction and characteristic features of portable machine tools on the example of a portable boring machine, milling machine and flange facing machine. The presented characteristics can influence the safety of work with these machines. The information given in the article were used to asses risk at the position of a portable machine tool operator. The assessment was conducted using the Risk Score method taking into account four stages of using portable machine tools, i.e. transport, assembly/disassembly, machining and maintenance. The result of the conducted risk analysis is the proposal of possible risk reducing actions. Due to the specificity of the operation of portable machine tools which significantly impedes the development of a machine tool which would be safe in and of itself, the proposed actions refer mainly to organisational solutions. The work presents also the thesis that it is possible to decrease the risk at this position thanks to the use of numerical control in a portable machine tool. Such a solution may reduce exposure to some identified threats. The issue is presented on the example of a prototype of a portable flange facing machine developed in the Institute of Mechanical Technology ZUT in Szczecin.

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