机械英文翻译_机械类英文翻译

机械英文翻译由刀豆文库小编整理，希望给你工作、学习、生活带来方便，猜你可能喜欢“机械类英文翻译”。

Cutting tool design Physics of metal-cutting provide the theoretical framework by which we must examine all other elements of cutting tool design.We have workpiece materials from a very soft, buttery consistency to very hard and shear resistant.Each of the workpiece materials must be handled by itself;the amount of broad information that is applicable to each workpiece material is reduced as the distinctions between workpiece characteristics increase.Not only is there a vast diversity of workpiece materials, but there is also a variety of shapes of tools and tool compositions.The tool designer must match the many variables to provide the best poible cutting geometry.There was a day when trial and error was normal for this decision, but today, with the ever-increasing variety of tools, trial and error is far too expensive.The designer must develop expertise in applying date and making comparisons on the basis of the experience of others.For example: tool manufactures and material salesmen will have figures their companies have developed.The figures are meant to be guidelines;however, a careful examination of the literature available will provide an excellent place from which to start, and be must cheaper than trial and error.Material removal by machining involves interaction of five elements: the cutting tool, the toolholding and guiding device, the workholder, the workpiece, and the machine.The cutting tool may have a single cutting edge or may have many cutting edges.It may be designed for linear or rotary motion.The geometry of the cutting tool depends upon its intended function.The toolholding device may or may not be used for guiding or locating.Toolholder selection is governed by tool design and intended function.The physical composition of the workpiece greatly influences the selection of the machining method, the tool composition and geometry, the rate of material removal.The intended shape of the workpiece influences the selection of the machining method and the choice of linear or rotary tool travel.The composition and geometry of the workpiece to a great extent determines the workholder requirements.Workholder selection also depends upon forces produced by the tool on the workpiece.Tool guidance may be incorporated into the workholding function.Succeful design of tools for the material removal procees requires, above all, a complete understanding of cutting tool function and geometry.This knowledge will enable the designer to specify the correct tool for a given task.The tool, in turn, will govern the selection of toolholding and guidance methods.Tool forces govern selection of the workholding device.Although the proce involves interaction of the five elements, everything begins with and is based on what happens at the point of contact between the workpiece and cutting tool.The primary method of imparting form and dimension to a workpiece is the removal of material by the use of edged cutting tools.An oversize ma is literally carved to its intended shape.The removal of material from a workpiece is termed generation of form by machining, or simply machining.Form and dimension may also be achieved by a number of alternative procees such as hot or cold extrusion, sand casting, die casting, and precision casting.Sheet metal can be formed or drawn by the application of preure.In addition to machining, metal removal can be accomplished by chemical or electrical methods.A great variety of workpiece may be produced without resorting to a machining operation.Economic considerations, however, usually dictate form generation by machining either as the complete proce or in conjunction with another proce.Cutting tools are designed with sharp edges to minimize rubbing contact between the tool and workpiece.Variations in the shapes of the cutting tool influence tool life, surface finish of the workpiece, and the amount of force required to shear a chip from the parent metal.The various angles on a tool compose what is often termed tool geometry.The tool signature or nomenclature is a sequence of alpha and numeric characters representing the various angles, signification dimensions, special features, and the size of the nose radius.This method of identification has been standardized by the American National Standards Institute for carbide and for high speed steel.