Cold thread Forming – the chipless alternative for high resistant internal threads

In the area of construction and mechanical engineering the designers and production engineers very often do have the task to produce high resistant connections with the possibility of assembling and de assembling parts in a wide range of different materials. Most often connection bolts and internal threads are used to fulfill this task. To produce the internal threads typically the three following internal threading technologies are used: tapping, cold thread forming and thread milling. Tapping and thread milling are metal cutting technologies but cold thread forming is a chipless alternative. Due to the cold forming of the thread this process does have several benefits in comparison to the traditional cutting technologies, but also some special features and process characteristics have to be considered, that it is possible to produce reliable internal threads. In the article the technology is presented with information about the process characteristics, the modern tools design and typical application areas. Results of pull out tests are showing the possibility for producing high resistant threads

Flow drilling technology and thread forming - an economical and secure connection in hollow sections and thin-walled components

Detachable and highly loadable screw connections can only be realized in thin-walled components and in particular hollow profiles with great effort. The flow drilling technology and subsequent thread forming represents an economical and technically interesting manufacturing alternative. With Flow drilling, a bush is generated by a fast-rotating carbide taper mandrel and a high resistant internal thread can be produced in a subsequent manufacturing process. Conventional weldor rivet nuts can be replaced in many application areas

Dimensioning of the Clearance as a Means of Avoiding Burr and Film Formation during the Punching of PC/ABS Cable Ducts

The production of staple articles such as cable ducts offers reductions in resource and production energy consumption if the process is optimized. Side recesses made of polyvinyl chloride (PVC) have already been punched successfully as one of the process steps during the production of cable ducts. However, punching cable ducts made of flame-retardant polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) is challenging because increased burr and film formation occurs. This study introduces the correct dimensioning of the clearance as a means of reducing the burr and film formation and presents the ideal clearance dimensions. This new process design approach comprises the dimensioning of the clearance and its subsequent successful application. Tools with clearances in the relevant size range were purchased and examined by means of punching tests. The punch-outs were evaluated regarding the quality characteristics, such as the burr, film, cut surface quality, shear droop, and plastic flow characteristics. Excerpts from high-speed recordings were used to assess the punch-outs qualitatively. The burr formation is significantly decreased by the use of a correctly dimensioned clearance, allowing for the crack initiated at the punch side and the crack initiated at the die side to meet perfectly. It is assumed that film formation can be avoided via a significant reduction in the friction or heat input during the punching process

Process development for punching extruded PC based materials in cable duct production

Burr and film formation occurring when punching polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) cable ducts is a common problem during manufacturing of cable ducts. However, little knowledge on base materials, their thermal and mechanical behavior as well as their initial processing and finally behavior during cable duct manufacturing is available. Therefore, to improve process reliability and gain knowledge on mechanical and failure behavior necessary initial investigations focus on cable duct usage, different geometric types, polymer materials and the punching process itself. Optical analysis on punched PC/ABS cable duct with burr and film formation and corresponding punch led to definition of the test tool’s geometry for subsequent tests. Since the punching process directly influences burr and film formation, it was necessary to design a demo-tool to observe the burr and film origin. Tensile tests at different test speeds focus on in-situ mechanical behavior using coupons taken from industrial cable ducts made of mineral reinforced polycarbonate (PC) and PC/ABS including further additives that are generally used in industry. First results indicate that higher test speeds appear to reduce the influence of the different admixtures on the elongation behavior of PC based materials

Dimensioning of the Clearance as a Means of Avoiding Burr and Film Formation during the Punching of PC/ABS Cable Ducts

The production of staple articles such as cable ducts offers reductions in resource and production energy consumption if the process is optimized. Side recesses made of polyvinyl chloride (PVC) have already been punched successfully as one of the process steps during the production of cable ducts. However, punching cable ducts made of flame-retardant polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) is challenging because increased burr and film formation occurs. This study introduces the correct dimensioning of the clearance as a means of reducing the burr and film formation and presents the ideal clearance dimensions. This new process design approach comprises the dimensioning of the clearance and its subsequent successful application. Tools with clearances in the relevant size range were purchased and examined by means of punching tests. The punch-outs were evaluated regarding the quality characteristics, such as the burr, film, cut surface quality, shear droop, and plastic flow characteristics. Excerpts from high-speed recordings were used to assess the punch-outs qualitatively. The burr formation is significantly decreased by the use of a correctly dimensioned clearance, allowing for the crack initiated at the punch side and the crack initiated at the die side to meet perfectly. It is assumed that film formation can be avoided via a significant reduction in the friction or heat input during the punching process

Positioning, Structuring and Controlling with Nanoprecision

Abstract. Key industries such as the automotive, electronic, medical and laboratory technical industries have continually rising demands for precise manufacturing, handling and control techniques. This is true for the manufacture of injection nozzles for engines as indeed also for the irradiation of extremely fine wafer structures and in the field of scanning probe microscopy

Estudo na Formação de Cavaco na Furação a Seco do Aço AISI P20 Endurecido

A adequação dos processos de usinagem com o intuito de eliminar a utilização de fluidos lubrirrefrigerantes na usinagem é complexa, principalmente nas operações de furação, devido às particularidades que caracterizam este processo. Com a retirada do meio lubrirrefrigerante, ocorre um aumento do atrito entre a broca, a peça e o cavaco, e consequentemente uma maior quantidade de calor é gerada pelo processo. Sendo assim, para a viabilização da furação a seco, é necessário avaliar a interface de contato entre a ferramenta e a peça, de forma a identificar as alterações geradas pela ausência do fluido lubrirrefrigerante. Durante a realização de testes a seco utilizando brocas de metal-duro, na furação de aço endurecido, foram observados problemas no escoamento do cavaco gerado pelo processo, causando o entupimento dos canais das brocas, e a consequente quebra prematura das mesmas. Para investigar estes problemas, foi realizada uma análise microscópica em uma broca quebrada alojada no interior do furo. Realizando o embutimento em resina de um cilindro contendo a parede do furo e a broca, foi viabilizado o corte do conjunto de forma a avaliar o contato entre a peça e a ferramenta em diferentes profundidades do furo. Por meiodesta análise foi verificada a ocorrência de corte do material pelas guias da broca, sendo este mecanismo prejudicial ao processo, pois estes elementos da ferramenta não são projetados para realizar o corte principal do material. A partir destes resultados, a estratégia de usinagem empregada no processo foi modificada, o que proporcionou uma melhora significativa no escoamento do cavaco e o cessamento das quebras de ferramentas