相机胶卷压簧多工位级进模设计
移动区域内的任何一个人都可能产生伤害”
“一旦你识别这些任务并能对这些任务中产生的危险进行分析，然后你就可以像预计这些危险会产生一样对这些冒险进行估算” O’Laughlin接着说，“这种发生的相似性指示了金属成型工艺师应该怎么做来阻止危险的进一步蔓延。B11.TR3的相似性可以分为高、中、低和可忽略的。冒险估算是基于把可能严重的伤害，把灾难降低到最小的程度。”
O’Laughlin说，下一步任务就是降低风险。
“例如，严重伤害的高发性的可能性就使得防止身体的任何部位暴露在危险面前的设备变得非常的有必要。”他说，“这就可能包括了安全防护障碍的设置及其他有特殊固定装置的保护装置，这些保护装置可以阻断雇用工靠近危险区域的通道。在这些环境下工作的这些控制系统必须有自我监测功能，以保证这些安全屏障必须迅速的作出反应，同时他们必须是闲置的。最小程度的冒险——几乎可以忽略的——以为着你必须对这些危险有一定了解，并有意识地去防止疏忽引起的伤害。补偿措施可以是一个可移动的显示屏或者一个信号。控制系统没必要必须是闲置的。”
O’Laughlin建议在风险降低完成之后要对任何可能残留的或者遗漏的风险进行重新估算。金属成型工艺师必须确定残留的风险是可忽略的或者还应该做一些额外的工作。通过培训可以使工人对残留的风险有个及时了解，可以使他们之得到仍然有一些风险依然存在。这些培训材料应该存档，并每年进行更新。
风险商机
让新的标准得到顺利的接受和执行的责任就落到了职业安全与卫生管理局和他在各州代理处的肩上了。我们都对职业安全与卫生管理局研究开发与检查单位所能产生的作用是毋庸置疑的。O’Laughlin说，心理上的接受是简化对这一标准（适应）及对各种信息记录的过程的最佳途径。
他老是喜欢这样说“如果你不能证明你所做过的事情，那么相当于你什么也没有做”“如果我没办法证明我做过和没做的事情，或者我为什么这样做，对我而言，我很难确定这在法律意义上是不是行得通，至少比确定伤害案还要多出个一年半载的时间。”
我们有些人总是对规划中的一些新的标准感到害怕。因为这意味着又多了一个必须遵守的规则，也多了一个对某些事情不必那么顺从的可能性。但是不管你喜欢还是不喜欢，标准都是没有办法更改的，特别是在像金属成型中存在的固有的危险这个事实一样。做好你自己在风险估算中的工作，参加金属成型的第三届技术研讨会，因为它就近在眼前了。
“聪明的律师会记录哪个工业标准没有被正确遵守，那将给他赢来更高数额的罚款” O’Laughlin补充道，“一些商家没有在他们所使用的设备上做任何的安全加强工作，这些正在运行的设备跟刚买来时没有什么两样。一些人认为相对于加强安全工作的花费而言，当有人受到伤害时接受罚款和支付医药费就来的便宜得多了。但是越来越多的州正在执行更加严厉的罚款。有时，如果是故意为之的话，将会被判重罪甚至是受到监禁或者打入监狱。”
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上海理工大学本科毕业（设计）论文
英文原文：
The pursuit of proper lube strategies
Choosing the correct stamping lubricant and application method pays off in rapid ROI, higher-quality parts and greater process productivity.
BY LOUIS A. KREN, SENIOR EDITOR
Metalforming lubrication has been referred to as art as well as science. Subtle differences in forming process, die design and workpiece metallurgy can greatly affect lube performance. Adding variables to the process is the array of application methods available— flood systems, targeted programmable sprays, sheet roller coaters and the like—can make the entire lubrication process a difficult journey to navigate. With that in mind, MetalForming consulted lubricant and application suppliers to try and demystify the lube process. Opinions vary on the right lube and method of application, but the information ahead will help you consider various options and conduct informed conversations with suppliers. How Lube Works
Lubricants act to control friction, reduce tool wear, prevent galling and dissipate heat, according to Rick Klann, who has spent 26 years with Franklin Oil and Fuchs Lubricants. He frequently conducts seminars for Precision Metalforming Association on the topic. While heat dissipation is a function of the lube-carrying vehicle—water, for example—lube mechanisms such as hydrodynamic lubrication, boundary lubrication and extreme-pressure (EP) lubrication carry out other actions. Hydrodynamic lubrication, also referred to as fluid-film lubrication, is important in automotive-engine lubrication but offers virtually no use in metalforming, as its effectiveness diminishes when confronting tooling-workpiece force and temperatures in the tooling, according to Klann. But polar additives, which attract to the work material, make boundary lubrication a viable option. Here, the lube forms a barrier on the workpiece that protects tooling and sheet.
Boundary lubricants, which may be fat derivatives or soaps, also enhance the wetting characteristics of lubricants, ensuring a good coating of the material surface, according to Klann. Because such lubricants have a melting point of about 100 C, they frequently are combined with EP lubricants. Both types of EP lubricants—mechanical and chemical—are effective in separating the tool and workpiece, thus controlling friction, reducing tool wear and preventing galling. Typical mechanical EP additives include calcium carbonate and molybdenum disulfides.
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相机胶卷压簧多工位级进模设计
Though effective, mechanical films tend to be messy, build up on equipment and become incompatible with postprocessing, says Klann. For this reason, chemical EP additives such as sulfur, chlorine or phosphorous find greater use. Chemical EP additives, unlike their mechanical cousins, react at the tool workpiece interface, forming metallic salts that act as the sacrificial surface.
With recent significant research in the area of nonchlorinated EP additives, this technology approaches the effectiveness of chlorine—preventing tool wear and galling with advantages in interim corrosion protection, post-process compatibility and ease of disposal.
Because each additive works best in a particular temperature range, according to Klann, some severe metalforming operations require a combination of lubricants for maximum effectiveness. In addition, EP requirements vary according to forming process, notes Klann. For example, simple piercing operations may not need chemical EP additives, but using chlorine, sulfur or phosphorous may dramatically improve tool life as the chemical film protects a punch during retraction—when most punch wear occurs. Stretch forming—where workpiece material flows over the punch—may not require EP additives as the speed of the operation does not generate high localized heat. Here, boundary lubrication may be most effective. But deep drawing creates a large amount of localized heat at the die radius and straightening zone, requiring an effective EP package. As most formed parts require several types of forming operations, a range of boundary and EP lubricants are needed to cover the range of encountered frictional forces. Lube Classification Metalforming lubricants can be categorized as straight oil, water-soluble oil, synthetic and dry film, according to Klann. He breaks down those classes:
? Straight oil.
Also referred to as neat oil, this uses a mineral-oil base with added polar and EP additives. Such products provide excellent interim corrosion protection after forming. But, they don’t always effectively dissipate heat and may require slower forming speeds. Also, they lack compatibility with postprocesses such as welding or painting, and often require prior cleaning.
? Water-soluble oils.
Though similar to straight oils, these also contain emulsifiers that suspend oil droplets and form an emulsion. A popular type of lubricant, water-soluble oil combines the benefits of straight oil while effectively dissipating heat. Though acceptable, interim corrosion protection lags behind that of straight oil and cleaning prior to postprocessing still may be necessary. After dilution by water, water-soluble oil is more costeffective than straight oil.
? Synthetics.
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上海理工大学本科毕业（设计）论文
Defined by most lubricant manufacturers as nonmineral-oil products, these are extremely complex, containing as many as 30 ingredients. Their water-based nature offers excellent heat dissipation and they usually are compatible with postprocessing, but offer only limited interim corrosion protection.
? Dry-film lubricants.
Dry-film lubricants applied to blank or strip steel, feature new compositions and offer benefits in handling and cleanliness, and are very effective in reducing frictional forces. While the cost of application is an issue, they can be an excellent choice on large single-hit parts, but Klann does not recommend them for multi-station forming unless they are used in combination with other lubricants applied during forming. Water-soluble oils and synthetics are good options in multi-station forming as the process builds considerable heat. Application Deserves Attention
“Get the lube where it’s needed, when it’s needed and in the amount that’s needed,” says Bryan Pax, plant engineering manager for stamper Pax Machine Works, Celina, OH, whose sister company and next-door neighbor Pax Products supplies in-die spray-nozzle lube systems. Numerous application methods can be used to reach that ideal, including prelubed stock; dry film added to stock; in-die spray, sometimes using targeted spray nozzles and preprogrammed control of lube output; roller coaters that apply lubrication to sheet prior to entering the die area; spray nozzles that apply a thin lube coat to stock prior to entrance into the tooling and systems that employ roll-coating and downstream spray nozzles. “
If a stamper chooses the right lubricant, its application method can rest on what is most cost-effective for the application,” says Scott Barrier of Stamping Specialty Co., Spencer, IN, a maker of rollcoating systems and supplier of lubricants. He feels that rollcoating offers an excellent option for a variety of forming processes and for wider strip, say 40 in. and wider, as spray lubrication of larger stampings may use excessive lube and release a fog that collects on ceilings, equipment, floors and operators. In progressive-die operations that stretch out over several stations, rollcoating may need to be augmented by spot spraying, Barrier says.
“The application method should be selected based upon the correct lubricant, although sometimes the reverse occurs,” Klann points out. “Rolling lubricant onto sheet for a
difficult-to-form part in a progressive die would mean a heavy, viscous lubricant, necessary to make sure it stays on the material into the fourth or fifth stage where ironing or sizing may occur. The viscous lubricant is not as effective in dissipating heat and could require slower production speeds. Choosing a water-soluble or synthetic for better cooling would require an in-die spray system. Here, only rolling the lube on would not be effective, as water-diluted lubricants typically do not have the film strength needed to stay on the part at later die stages.”
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相机胶卷压簧多工位级进模设计
Precise control of lube delivery saves money in fluid costs, but savings don’t end there, according to information from Unist, Inc., Grand Rapids, MI, a developer of roller-lubricator systems that supply lube pumped from inside the rollers. Other downstream cost savings result from less fluid to clean on the factory floor, simplified part cleaning, reduced paint blisters and lower environmental costs.
Many stampers use more lube than is actually needed, says Claude Bergeron, a business development manager at EFD, East Providence, RI. The company produces a system incorporating low-volume low-pressure technology to apply lube as a uniform film.
“Traditional application methods may lack the control needed to provide consistent coverage, increasing the risk of dry spots and tool damage,” he says. “As a result, stampers can over-apply lubricant to ensure complete coverage. But this may produce problems such as accelerated punch wear and excessive lube costs. We recommend determining the optimum lube level for each job, then finding an application system that can maintain that level.”
Lube at the Press— Only Half the Battle
Whatever application method is chosen, stampers should consider not only how the lube reaches the workpiece material, but its delivery to the plant and to the presses. Lugging around buckets to fill a reservoir at each press takes time and takes employees away from other tasks, while the press sits idle. A central lube mixing, storage and delivery system may solve that problem. On the other hand, manual lube transportation brings a sense of accountability and an awareness of how much lube is consumed. “
”Central systems actually can waste lube,” cautions Bergeron. “Some companies, in switching to central feeding, told us that their lube usage had increased two to three times. It almost creates this invisible supply line where no one takes responsibility to track usage.” Storage and Disposal
Regulatory issues dramatically affect the economics of metalforming-lubricant selection, says Klann. Recyclable products should be considered, especially if they enhance the forming process and reduce disposal costs.
“As the waste generator, metalformers are responsible for proper waste treatment,” Klann says. “Even if the lube supplier says a lube can be dumped down the drain, the metalformer bears liability.” With that in mind, make sure disposal meets all affected regulations.
Following the quality-system requirements of ISO 9000, the ISO 14000 series of standards incorporates environmental aspects into operations and product standards. Many metalformers may be evolving to this standard set either proactively or as directed by customers. ISO 14001 specifies requirements for establishing an environmental policy, determining environmental
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