|
A mandrel (; also mandril or arbor) is one of the following: * an object used to shape machined, or electroformed, work. * a tool component that grips or clamps materials to be machined. * a tool component that can be used to grip other moving tool components. == Variants == An example of one type of mandrel is a shaped bar of metal inserted in, or next to, an item to be machined or bent in a certain pattern. Exhaust pipes for automobiles are frequently bent using a mandrel during manufacture. The mandrel allows the exhaust pipes to be bent into smooth curves without undesirable creasing, kinking, or collapsing. Molten glass may be shaped in this way as well. Another example of this type of mandrel is found in jewelry manufacturing, where ring and bracelet mandrels are used to shape metal into a desired size and shape, using a tiny hammer to beat the metal against the mandrel. Another type of mandrel is the clamp that a lathe uses to hold pieces of wood, metal or plastic to be machined as they are turned. In this way, rods can be threaded, furniture legs are turned to have beautiful patterns, and irregularly-shaped objects can be given a cylindrical or round shape. There are several types of mandrels used with lathes. Original expanding mandrels are slightly tapered with a tapered wedge that will expand to hold the item. The Xpandrel method of expanding mandrels was introduced in the mid 1990s. This method used basic mechanical principles of deformation to achieve expansion of a non-tapered mandrels. Using various methods of actuation the body of the mandrel is deformed below the limit of elasticity to provide repeatable holding forces without typical deformation caused by pressing on tapered mandrels. Other commercial mandrels are very slightly tapered and the hollow object slides down the taper until it 'sticks'. The shop-made mandrel shown in the photo is designed to clamp a hollow tube or gear between the two tapered plugs. There is nothing about such a mandrel that can't be made right on the lathe on which it is to be used so it is not uncommon for machinists to make a mandrel to hold a particular item, and then set the mandrel aside hoping to use it again some day. Mandrels of this type are usually set in the lathe on centers and turned with a lathe dog. The third type of mandrel discussed here is that which is used to hold circular saw blades, buffing wheels (used for polishing), and sanding discs onto drills, circular saws, and similar power tools. A mandrel of this type generally consists of a cylinder, threaded on one end, with a washer brazed onto the threaded end and an accompanying screw and second washer used to clamp the circular saw blade, sanding media, or other rotary tool onto the mandrel. While most mandrels are driven by direct connection to an electric motor or engine, other mandrels are driven by attachment to a bearing-supported, pulley-driven shaft. In the aviation industry, mechanics use mandrels in various lengths to accommodate grip ranges of material thickness. Blind bolt and blind nut assembly tooling consists of a Power Unit and Driving Tool (Gun). Over time, wear in the Nose Assembly requires replacement of the anvil chuck or mandrel involved in installing the various blind bolts or blind nuts. Commonly referred to as Blind Bolt Mandrels, the mandrels are the most frequently replaced items. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「mandrel」の詳細全文を読む スポンサード リンク
|