Experimental research of ploughing extrusion forming multi-tooth tool wear and damage mechanism and workpiece defects

According to the characteristics of ploughing extrusion forming and the theory of metal cutting, the wear and damage mechanism, common wear and damage forms and causes of multi-tooth tools in ploughing extrusion forming are analyzed. Then, the correctness of the analysis of tool wear and damage mechanism and common wear and damage forms is verified by field cutting experiments. At the same time, the phenomena and causes of workpiece stagnation and cracks in the process of ploughing and extrusion forming were obtained through experiments. Finally, the reasonable processing parameters of ploughing and extrusion forming multi-tooth cutting tool were obtained.

A Comprehensive Micro-milling Force Model for A Low-stiffness Machining System

Micro-milling is widely used in various crucial fields with the ability of machining micro- and meso-scaled functional structures on various materials efficiently. However, the micro-milling force model is not comprehensively developed yet when tool feature sizes continually decrease to under two hundred microns in a low-stiffness system. This paper proposes an analytical force model considering the influence of tool radius, size effect, tool runout, tool deflection, and the actual trochoidal trajectories and the interaction of historical tool teeth trajectories (IHTTT). Different micro-milling status are recognized by analyzing the cutting process of different tool teeth. Conditions of single-tooth cutting status are determined by a proposed numerical algorithm, and entry angle and exit angle are analyzed under various cutting conditions for the low-stiffness system. Three micro-milling status, including single-tooth cutting status, are distinguished based on the instantaneous undeformed chip thickness resulting in three types of material removal mechanisms in predicting micro-milling force components. Discontinuous change rates of undeformed chip thickness are found in the low-stiffness micro-milling system. The proposed micro-milling force model is then verified through experiments of micro slot milling Elgiloy alloy with a 150-µm-diametrical two-teeth micro-end-mill. The experimental results show a Root-Mean-Square Error (RSME) of 0.092 N in the predicted resultant force, accounting for approximately 5.12% of the measured force, by which the proposed theoretical model is verified to be of good prediction accuracy.

FORMATION OF WORKING SURFACES OF A WORM WHEEL AND A WORM WITH A TOOTH-CUTTING TOOL WITH A MODIFIED PRODUCING SURFACE BY THE METHOD OF COMPUTER SIMULATION

Substantiated the relevance of theoretical studies on the use of modern CAD systems, which make it possible to move away from the analytical description of interacting surfaces and focus on the implementation of algorithms for their interaction. The use of geometric modeling tools for virtual imitation cutting of elements involved in the formation of a worm pair is shown. The use of a modified generating surface is shown to introduce errors that inevitably arise when trying to form and use a real worm pair.

FILOSOFIS DAN MAKNA BALE SAKANEM DI PETANG, BADUNG.

Traditional Balinese house architecture is a work that is born from the traditions, beliefs and spiritual activities of the Balinese people which are manifested in various physical forms, such as traditional houses, sacred places (places of worship called temples), meeting halls, and others. The birth of various physical manifestations is also caused by several factors, namely the geography, culture, customs, and socio-economic conditions of the community. One of the buildings in a traditional Balinese house is the Bale Dangin. Bale Dangin is located in the eastern part of the Balinese Hindu community yard. Bale Dangin has the main function as a place to make and place ceremonies for Manusa Yadnya ceremonies such as metatah (tooth cutting), otonan, pewiwahan natab in bale and other activities. Along with the development of the times like nowadays, Bale Dangin buildings are rarely found in Hindu community houses in Bali, there are several factors affecting this, from the land that is owned is narrow / only enough for the main building to the factor that people are less interested in traditional buildings on the grounds that they are not modern and with the times. So that there is a change in the meaning of the Bale Dangin Building itself. In addition to changes in meaning, there is also a change in the materials used in the construction of the Bale Dangin building, after searching data by interviewing and field observations, it is known that things that affect changes in the use of Bale Dangin materials are due to climate / weather, developments existing architectural styles and the state of the community economy. The purpose of this research is to discuss how the function and meaning of the existence of Bale Dangin, especially Bale Dangin Sakanem in Hindu community homes in Bali, and to find out what materials can be used to produce Bale Dangin buildings that are still up to date with the times but do not reduce the value of philosophy and meaning of Bale Dangin itself so that it can survive amid the development of architectural styles in Bali.

Performance evaluation of high capacity mechanised dehusking equipment for green arecanut (Areca catechu L.)

India is a major arecanut (Areca catechu L.) growing country. Of the many problems identified in arecanut processing, dehusking is found to be a major one, which is cumbersome and needs to be mechanised. Presently, there are a few types of equipments available, but these machines are basically of low capacity and cater to small arecanut growers. Performance evaluation of three high capacity green arecanut dehusking equipments was taken up, to work out its possible adoption for entrepreneurship development. Equipment under evaluation consisted of power mounted dehusker with hook tooth cutting blade fixed in a cutting wheel to dehusk the outer shell with a nut ejection system coupled with a vibrating deck of trays to grade and convey the dehusked nuts. The Blade-Knurl shaft speed ratio was optimised as 1:11. Whole nut recovery per cent ranged from 81.84 ± 1.87 to 82.52 ± 1.95 per cent. The unhusked per cent and partially husked percentage ranged from 7.60 ± 3.71 to 7.81 ± 4.68 and 8.29 ± 2.15 to 8.85 ± 2.82, respectively. The broken nut percentage ranged from 1.03 ± 1.36 to 2.06 ± 2.72 percentage. The total cost of operation for two-belt, four-belt and six-belt model was ` 162 h-1,` 237 h-1 and ` 262 h-1, respectively. Better dehusking efficiency with reduced damage to the nuts achieved in mechanical dehusking would enable the farmer to realise additional yield with saving in time and lower cost of operation.

A Method of Profile Modification of the Tooth Surface of Semi-Rolled Pan Gear

The use of drives based on pan precession gears with a small shaft angle in which multiple-tooth meshing is implemented significantly increases the efficiency and transmitted torque in oil and gas equipment. It also and reduces the breakaway torque by almost an order in comparison with worm gears. The production of pan gears in the semi-rolled version significantly simplifies tooth cutting technology. To exclude the possibility of edge contact of the teeth coming into meshing due to their contact and bending deformations, it is necessary to carry out profile correction of the teeth. To address this issue, a method utilizing a tool with a straight cutting edge displaced from the axial plane of the tool is proposed. Using cutting of the wheel teeth of a semi-rolled pan gear with the proposed tool as an example, calculations of the total profile errors and the tooth surface curvatures are performed to further determine the contact loading of the gear.