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- 3 Tháng hai 1985 (Tuổi: 38)
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Metal Forging Tools and Equipment and Parts Supplies
- Sinh nhật:
- 3 Tháng hai 1985 (Tuổi: 38)
This article discusses the significant factors in the selection of forging equipment for a particular process. It describes the characteristics of forging hydraulic presses, mechanical presses, screw presses, and hammers. The article discusses the significant characteristics of these machines that comprise all machine design and performance data, which are pertinent to the economic use of the machines, including the characteristics for load and energy, time-related characteristics, and characteristics for accuracy.
The forging of metals and alloys is one of the oldest metal forming techniques used by humankind. Forging processes were improved over the centuries and are still being refined. Today, we are certain that there is no limit to these improvements and that we will never reach the point when we can say that nothing more is to be done. Despite the enormous knowledge and experience gained over the centuries, we still face new challenges arising from civilizational progress. One of them is the necessity to produce parts that are more and more complex in terms of shape and properties, which requires not only a deep insight into phenomena that accompany forging processes, but also the development of new techniques, riveting machine and equipment, materials, research methods, and tools, as well as the improvement of the existing ones. With the Special Issue on “Forging Processes of Materials”, the Editorial Board of Materials offers authors the possibility of presenting their findings in this field. As the Guest Editor for the Special Issue, I would like to invite you to contribute to this publication, which, I hope, will serve as a source of knowledge for both theoreticians and practitioners. Hence, I encourage authors to submit papers exploring, in a broad sense, the theory and practice of forging metals and alloys. I wish to assure you that we will make every effort to ensure the highest quality of this Special Issue.
Forging is a hot or cold metal deformation process used to produce metal parts where strength is a paramount concern, engine connecting rods and hand tools being two such examples. The process itself involves using compressive forces to mold and deform metal into the desired shape. For most applications, forging entails heating the base metal until it is malleable enough to work with, although cold and warm forging are also done.
The forge, sometimes called a hearth, is the component that heats the metal prior to forming. In its most fundamental form, forging can be understood in the manner of making horseshoes. The blacksmith heats the metal in the hearth, then pounds it with a hammer against an anvil to flatten it, curve it, pierce it, and generally shape it, repeatedly reheating the metal to maintain plasticity. Small gas-fired forges are available for blacksmiths though many forgers choose to build their own.
Modern industrial forging relies on sophisticated, heavy-duty equipment capable of producing small accurate parts as well as large pieces weighing many tons. As with castings and weldments, many forgings are machined after they are made to achieve their final forms.
An anvil is a large slab of metal, usually made of steel, which serves as the workbench for the blacksmith or automated hydraulic closed die forging hammer device. The metal is placed on the anvil, where it is hammered into the correct shape. Anvils traditionally provide a flat hammering surface, though curved anvil tops are available. A hardy hole and punch hole can sometimes be found on an anvil – the hardy hole serves as the square socket for accepting the shank of a hardy, an interchangeable tool in a variety of shapes used for cutoff, bending, etc. The punch hole provides clearance for punching holes in the metal.
Chisels are cutting supplies that chip away at metal. They are traditionally made of high-carbon steel and consist of a long octagonal cross-section with a tapered cutting edge on one end. There are two types of chisels—hot chisels and cold chisels. Cold chisels are typically thinner in construction, and better suited for cold forging. Hot chisels, on the other hand, assist in hot forging processes. Chisels are traditionally applicable in manual forging applications.
Tongs assist in the transportation of the heated metal from the forge to the anvil. Many different tong shapes are available to provide adequate gripping of multiple metal shapes and sizes.
Forming tools that create grooves or indentions in the forging process are known as fullers. Fullers also help round out corners and stretch the metal. Traditionally used in pairs, fullers work through placing one beneath the metal, and the other on top. This enables the indentation of both sides of the metal component to occur simultaneously.
Different forging processes are appropriate for different applications—options such as hot forging, cold forging, closed die forging, upset forging, and press forging are simply a few examples. Many of these forging processes require the use of a hammer to enable compression and shaping of the metal. Forging hammers vary in shape, size, and material based on the particular application, but all industrial hammers typically apply force with a large ram. Two basic types of hammers are:
Drop hammers: Gravity allows the heavy ram to fall onto the metal.
Power hammers: Compressed air, hydraulics, or electricity drive the hammer.
Hammers are capable of delivering percussive impact blows with forces of up to 50,000 lbs. in their largest incarnations, with smaller capacity units also available. For increased forging forces, forgers turn to presses.
A forging press creates force through mechanical or hydraulic energy without relying on the weight of a hammer and the assistance of gravity to pound metal into the desired shape. Whereas hammers shape a localized portion of the metal, a forging press can forge the entire product at once in a process known as closed-die forging. Forging presses also duplicate the action of hammers in the open die forging process. Both horizontal and vertical forging presses are available. The horizontal presses are called upsetters. Two types of forging presses include:
Mechanical forging press: A mechanical device (often a crank) propels a motor-driven flywheel, forcing the ram against the metal. Mechanical presses are not suited for forging large or complex items but are beneficial in applications that require simple shaping effects. They are capable of producing forces of up to 20,000 tons.
Hydraulic forging press: High-pressure fluid propelled by hydraulic pumps forces the ram against the metal. Hydraulic presses can provide higher forces than mechanical presses, and are sometimes preferred for applications that create large or complex components. Small hydraulic presses are available for blacksmithing operations with forces starting around 10 tons and they grow increasingly more forceful from there, with some very large presses operating in the 50,000-ton range and beyond.
Forging presses used for closed-die forging require forging dies to properly mold the metal. Dies act as molds into which the hot, malleable metal is pressed. Since dies are unique to each forging project, they are expensive and can lead to high set-up costs prior to forging – forging with dies is best suited for moderate to large production runs. There are two main types of forging dies:
Open die: Open dies are akin to the blacksmith’s hammer and anvil and are usually available in shapes that accomplish specific tasks such as squaring. They do not completely encase the metal, providing free flow everywhere except where the metal meets the die. Open die forging is a good choice for custom metalworking applications as it can be used to produce as few as a single forging. It is also useful in forging very large parts. Where a blacksmith might use tongs to grapple the hot metal forging, many larger forgings are handled by mechanical manipulators because of their immense weight. Open die forging depends a great deal on the skill of the forger to produce the desired shapes. In addition to producing stepped shafting, rings, and cylindrical hollows, open die forging is often used to produce the hemispherical ends of pressure vessels.
Closed die: Here, the metal is completely encased. When the CNC hydraulic die forging hammer or press pushes against the metal, the metal flows and fills the die cavity or cavities. Typically, the pre-forged part will have some resemblance to the final forging before it is placed in the die, preformed by a series of so-called blocker dies.
This article presents a brief discussion of metal forging tools and equipment. For more information on other products, consult our other guides or visit the Thomas Supplier Discovery Platform to locate potential sources. More information on forging and forging equipment may be found at the Forging Industry Association website.
Modern science and industry have accumulated many efficient methods of forming by hammer forging, such as setting with shift or torsion, sectional forging, expansion by rolls etc. However, they are difficult for realization on forging equipment, what hampers their adoption in industry. Hence technological conservatism in forging. Even state-off-the-art forging complexes have brought no fundamental change into the hammer forging process.
Within the present work we have developed a new composition structure of a forging machine suitable for conventional operations of hammer forging as well as for new operations, unusual for hammer and press forging. The structure of the machine, hereinafter referred to as an automated forging center (AFC) permits to solve the problems of combining external forces, producing new shapes of deformation zones, efficient use of the tool magazine.
Physical and mathematical simulation of technological operations have been carried out to estimate forming and forse parameters, some results being presented in the paper.