Machine Ram Research Articles

Electrochemo-magneto abrasive flow machine setup fabrication and experimental investigation of the process alongwith mathematical modeling and optimization

In abrasive flow machining, there are two sets of piston-cylinder arrangements, i.e. machine and media. the machine ram pushes the media piston two and fro so that media filled inside it flows past the inner wall of workpiece and the material is removed. The extrusion pressure is the main mechanism of material removal. Various authors have made the process more effective in terms of material removal and surface roughness by providing rotational and magnetic force.

Influences of process and material parameters on quality of small-sized thin sheet-metal parts drawn with multipoint tooling

Multi-point tooling forming is one of the special categories of sheet metal forming techniques with good operational flexibilities due to using two sets of adjustable pins along the machine ram direction (vertical direction usually), which represent the acting points of desired forming-tool surface contours. Nevertheless, some defects may develop during forming under different process and machine-set conditions, such as wrinkles and undesired surface indents. This paper presents a study of the influences of possible process variations by adjusting the tooling as well as associated quality control when thin sheet-metals were drawn into the cap-type parts, being focused on the small-sized components. Effects of the curvatures to be formed, sheet material and geometry, holding force, lubrication condition and use of rubber as cushions on the formed component-geometry and surface quality have been investigated. The formed parts were measured with a Co-ordinate Measuring Machine and observed on the indentation with a high resolution Camera. The results showed that careful control of the process parameters and machine setup for the forming of thin sheet-metals for a particular type of the material and geometry is needed prior to the forming production uses with multi-point tooling forming, and use of rubber cushions and proper design of blank-holding are extremely important for successfully forming thin, small sized sheet-metal components with discrete pin-tools.

Method for measuring thermal distortion in large machine tools by means of laser multilateration

A new methodology to measure thermal distortion in large machine tools is proposed in this paper. The advantage of this method is that a single tracking interferometer can be used to measure thermal distortion of machines with large work volumes while maintaining low enough measurement cadence and uncertainty. A multilateration scheme is conducted using a single laser tracking device positioned on top of the machine table which is automated, and for each target point, all laser stations are reached prior to moving to the next target point; then, the whole measurement cycle is repeated during the test. For measuring angular thermal distortion, precision electronic levels are located in machine ram and column top; also, temperatures are registered in key points of the machine. Experimental measurements on a large column-type milling machine are done, and the effectiveness of the proposed methodology is verified.

Dynamic Characteristics Research of Boring-Milling Ram Based on ANSYS

This paper carried out the modal analysis for ram based on ANSYS, and calculated the first six natural frequencies and vibration modes and finally verified that the dynamic incentive caused by the spindle rotation on the ram does not produce resonance phenomenon generally. By adding harmonic load, made the harmonic response analysis based on the modal analysis, calculated displacement and stress responses of the system under the action of the exciting force and obtained the dynamics and the frequency response curve, that is, amplitude-frequency curve which verified the ram can withstand various sine loads of different frequency. The dynamic characteristics were studied and the dynamic parameters were obtained after the studies above, which provide important foundation for the design and improvement of the machine ram structure.

Compliance Correction for Determining Load-Line Energies for Compact Fracture Toughness Specimens

Abstract A compliance correction technique has been used to calculate energies in the compact specimen test measured at the specimen loading line using the machine ram displacement. The compliance-corrected results for nine pressure vessel steels tested at temperatures of room temperature, 71°C, and 177°C have been compared with the direct measurement (standard clip gage) approach, and the results show essentially a 1:1 relationship with a correlation coefficient of 0.997. This technique should be useful for determining elevated temperature, ductile fracture toughness values and for tests in which the normal clip gage (or other technique) fails to operate.