Wyniki wyszukiwania - BazTech

1

Using thermovision for temperature measurements during turning process

Molenda J., Charchalis A.

Journal of KONES

|

2018

|

Vol. 25, No. 4

293--298

EN

In metal cutting industries, machining processing, especially turning operation is very basic type of machining. For certain processes in manufacturing, it is favourable and necessary to have certain knowledge about heat generation and temperature rise (including average and maximum temperature) during machining process. Increment in maximum temperature at clearance face or at rake face of cutting tool causes the reduction in life of tool. Similarly, the quality of machined surface, a metallurgical structural alteration in tool and workpiece material also depends on the maximum temperature, temperature gradient and cooling rate of both tool and workpiece. Certain physical and chemical reactions that are developed during the cutting process are directly connected with tool wear, power consumption, surface roughness on work piece material and cutting temperature. The natural low of thermal energy gives significant relationship between cutting temperature and cutting parameters in order to improvement of cutting tool’s wok efficiency, quality and accuracy. The heat distribution in cutting tool, in formed chip and in workpiece material strongly depends on (mechanical and chemical) properties of cutting tool and workpiece material, cutting speed, depth of cut, feed rate, nose radius, geometry of tool, type of coolant used and other parameters. This work presents some results of research done during turning steel 235JR realized on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process temperature, realized for different materials.

2

Influence of lapping plate temperature on roughness parameters of specimens

Molenda J., Charchalis A.

Journal of KONES

|

2017

|

Vol. 24, No. 2

147--152

EN

Lapping is used in the production of components of the highest quality in terms of form finish accuracy and surface integrity. A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. This article goal was to check the influence of lapping wheel temperature on workpiece roughness after lapping process. In earlier work, authors investigated the dependence between time and the temperature of executory system elements. Tests showed that after five hours of machine working temperature stabilizes and slightly fluctuated around a certain value. Thus, this work concerns lapping results in this elevated temperature. Research was proceed during Al2O3 elements lapping. It was realised with use of ABRALAP 380 lapping machine. The lapping machine executory system consisted of three working conditioning rings. Executory system elements temperature was measured remotely by infrared camera Thermo Gear G100. Elements machining was started after 10, 140, and 270 minutes of machine working time. Studies showed that machine executory system elements temperature affected only the ΔRa parameter, which is higher for surfaces, which were processed starting from 270th minute of machine working time.

3

Results of lapping process executed in elevated temperature

Molenda J., Charchalis A.

Journal of KONES

|

2016

|

Vol. 23, No. 4

591--596

EN

Lapping is used in the production of components of the highest quality in terms of form finish accuracy and surface integrity. A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. This paper goal was to check the influence of temperature of executory system elements on lapping process results. In earlier work, authors investigated the dependence between time and the temperature of executory system elements. Tests showed that after five hours of machine working temperature stabilizes and slightly fluctuated around a certain value. Thus, this work concerns lapping results in this elevated temperature. Research was proceed during Al2O3 elements lapping. It was realised with use of ABRALAP 380 lapping machine. The lapping machine executory system consisted of three working conditioning rings. Executory system elements temperature was measured remotely by infrared camera Thermo Gear G100. Elements machining was started after 10, 140, and 270 minutes of machine working time. Studies showed that machine executory system elements temperature affected only the Ra parameter, which is higher for surfaces, which were processed starting from 270th minute of machine working time.

4

Emissivity of the one - plate lapping machine tool

Molenda J., Barylski A.

Journal of KONES

|

2012

|

Vol. 19, No. 1

283-288

EN

A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Typical examples of the processed components are pump parts, transmission equipments, cutting tools, hydraulic and pneumatics, aerospace parts, inspections equipment, stamping and forging. Lapping leads to a surface with low roughness and high precision. It is carried out by applying loose abrasive grains between work and lap surfaces, and causing a relative motion between them resulting in material removal. The grains activities in the working gap cause also temperature rise of the executory system elements, including lap plate. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. Temperature is the most often measured physical quantity, second only to time. All advantages of infrared technology have led it to become frequently used technique for temperature measurement. It was also used by authors for lapping process observation. To assure accurate noncontact infrared temperature measurement there is a need to keep in mind several factors, including determining appropriate value of emissivity. Incorrectly, designated emissivity results in bigger measuring error. This work presents a method for determining wheel emissivity and its value obtained by presented way. To find emissivity of the lapping plate infrared camera V-20 II produced by VIGO System S.A. and contact thermometer TES1312 Dual K-Type were used. The experiments were carried out on a plate-lapping machine ABRALAP 380 with a grooved cast-iron lapping plate and three conditioning rings. The determined emissivity was equal 0.95 and was bigger than value from the table, as was expected. During lapping wheel surface is in fact very dark due to charging and covering the waste slurry. Obtained value will be used in future measurements.

5

Determining the conditions for temperature measurements during flat lapping

Molenda J., Barylski A.

Journal of KONES

|

2011

|

Vol. 18, No. 3

293-297

EN

Lapping is used in the production of components of the highest quality in terms of form finish accuracy and surface integrity. A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. This work presents a part of results concerning temperature measurements conditions. Experiments were being conducted during flat lapping with use of ABRALAP 380 lapping machine and infrared camera V-20II produced by VIGO System SA. Firstly the influence of conditioning rings number on wheel temperature rise was investigated. It was proved that number of rings had a significant impact on temperature rise value and the highest were during machine working with all three rings. Then another test was made, to simulate the work during real 8-hours shift. The aim was to determine time of machine working after which temperature would stop rising. Temperature was measure during Al2O3 (95%) elements lapping with use of silicon carbide grains. Tests results showed that after five hours temperature fluctuated around a certain value. In future analysis temperature after five hours lapping will be taken into account.