基本端部形成方法是分段工具尺寸，RAM成形，旋转成形，辊形成和纺纱。后三个在围绕管的圆周工作具有特定的优点，特别是在尖锐的角度和自由基的变化需要更逐渐地工作管。前两次一次工作整个圆周。虽然它们提供更快的形成循环，但它们的应用范围有限。最常见的最终成形类型是RAM型终端前。大多数情况下，RAM型端部形成过程牢固地将管静态固定在一组夹具中，而RAM工具形成管的端部。随着RAM工具朝向夹具夹持的静态管的前进，RAM工具使管道冷却。流动路径是阻力最小的路径。Ram工具简单地夹在管的末端，然后将其压制在夹具模具上。在这种情况下，管在管道上的压缩负载下的夹具和RAM工具扣的管道的不受支写的部分，从而形成所示的珠子。在这种特殊情况下，RAM工具的配合特征的表面光洁度并不重要。 Likewise, lubricant in this case is not critical.

需要做结束形成的制造商有许多选择。即使在缩小到使用RAM或分段的工具之后，选择比比皆是 - 工具可以形成ID，OD或两者;并且操作可以是手动或CNC。了解流程及其功能是为应用程序选择最佳选择的键。

您的公司有机会提供管子组件，但需要结束形成，这是您没有的功能。互联网搜索“tube end forming” leads to a range of options. How do you sort through them?

Focusing on the function of the tubes to be reshaped, and not on the forming method, can lead you to select an end forming method that optimizes the part cost, particularly if the opportunity involves a new part. The ways to form the tube end boil down to a few basic methods, so understanding their capabilities and limitations is critical to selecting the best process for a particular part. Thinking about creative ways to employ the process can help to improve product performance and reduce process costs.

基本端部形成方法是分段工具尺寸，RAM成形，旋转成形，辊形成和纺纱。后三个在围绕管的圆周工作具有特定的优点，特别是在尖锐的角度和自由基的变化需要更逐渐地工作管。前两次一次工作整个圆周。While they provide a quicker forming cycle, they are limited in their range of applications.

This article focuses on applications for which segmented tool sizing and ram forming are the optimal methods, typically high-volume production for basic tube end forms.

定义成形要求

需要进行结束的制造商经常提出许多相同的问题，无论该项目是零件还是零件组装。形成的管需要什么？零件的所有功能是否必要？当前设计是否已经采用特定的形成方法？我们可以更改交配零件吗？我可以通过更少的零件获得相同的结果吗？

The tube alloy and production process are important factors regarding the part design and the forming method. Can the material accommodate the necessary amount of deformation? If so, what is the best way to work the material to achieve the end form? Is the tube seamless, or does it have a weld seam? What are the tolerances and the cosmetic requirements according to the print?

了解大会设计背后的假设对于优化最终成型过程是必要的。

For instance, the part design for an automotive exhaust component might be based on a particular assembly method, resulting in a two-piece welded assembly. Focusing solely on the application and cosmetic requirements might alter the part design, leading to a change in the forming method and a significant cost reduction.

After identifying the methods capable of forming a finished part to the customer’s specifications, you can evaluate the project’s unit production cost, which typically involves the tooling cost, repeatability, cycle time, setup time, and process adjustability (to accommodate material variations). Another question usually arises at this point: What else can I do with the machine?

RAM形成与分段工具尺寸

最适合RAM成型的最终形成应用也适用于分段的工具尺寸。但是，这些过程具有明显的差异。

Ram Forming。也称为推土、ram使用impa形成ct process to drive a tapered plug inside or a tapered cup over the outside of a securely held tube end (see Figure 1). The tapered angles convert this vertical (axial) force to radial changes in the tube end shape. The process works the full circumference of the tube end uniformly. The tooling is designed to smoothly transition the tube end to the finished contour and has allowances that compensate for spring back. Hydraulic systems typically are most effective in delivering the power and speed required.

Segmented Tool Sizing。分段工具尺寸在径向上进行管圆周作用。为了减少管子，该过程使用一组分段的模具，看起来像一块披萨片，中心切开（见图2）。末端前者将锥形环拉在模具套件外部的锥度上，将死亡挤压在一起，以减少管子的直径。每个工具段最初以两个点接触管。在过程结束时，段接触整个管围。

Expanding the tube relies on a similar approach. Segmented tools, or fingers, start out packed together so they fit inside a tube. A tapered arbor, driven by a hydraulic cylinder, advances through the center of the tooling to spread the fingers uniformly until the tube reaches the finished diameter. Like the external tooling, segmented fingers initially contact the tube at two points.

完成零件的精度

RAM形成是一种硬工具，提供了一致的成品零件。但是，它无法补偿管壁或直径的材料变化，并且无法调整以补偿弹簧返回量的变化。操作员通过更改圆柱行驶距离来调整分段工具，这决定了死亡距离近距离或手指的扩展。机器的控制系统确定了此过程的准确性和可重复性。

A drawback with segmented tooling is the amount it can change the workpiece’s diameter. The standard reduction is about 0.250 in. on diameter with each tooling set. Trying to do more is restricted by physical limitations. For reductions, the tooling can’t open up enough to receive the raw tube or close far enough to form the tube without having big gaps between the segments, resulting in significant ridges of material that are difficult to overcome. For expansions, you have the opposite problem. The fingers cannot collapse enough to accept the raw tube or to open (spread) enough to form the finished end.

化妆品考虑

成品管的外观外观是选择形成RAM或分段工具尺寸的主要决定因素。通常用于RAM形成的夹紧方法是一组颌骨 - 顶部和底部被压在一起。这可以沿着管的未成形部分带有夹具标记的夹具表面。在管子周围使用后背或夹式式夹具是固定管的一些替代方法。

分段刀具尺寸方法径向工作，并且不会产生任何轴向力，因此管不需要夹紧。然而，当管的直径减小时，管材料可以在模具之间挤压，损坏形成区域中的表面。当管材扩大时，差距开发为手指扩散，围绕圆周留下标记。双击过程（旋转管，旋转，再次锻炼）是典型的补救措施。

分段工具选择：仅内部或外部？或两者？

如果您选择分割工具,你没有完成ed. You also have to determine whether you need tooling on the ID only (for an expansion), on the OD only (for a reduction), or both. Using both ID and OD tooling, called I/O tooling, is suitable for expansions and reductions and achieves better roundness (because it flattens the pinch marks) and better definition at the transition between the formed and unformed areas.

An I/O system typically uses back-to-back hydraulic cylinders. One drives the tapered arbor for the fingers and the other drives the tapered ring over the dies. Be aware that I/O tooling more than doubles the tooling cost relative to the cost of ID-only tooling. The additional cost buys greater precision and accuracy.

Segmented Tool Sizing — Digital Versus Manual Controls

You have one more decision to make. If you have determined that segmented tooling in an I/O configuration meets your tube forming requirements, then the last decision is a matter of choosing digital controls or manual controls.

主要区别在于，数字（CNC）系统使用编码器来控制圆柱体的行驶，从而控制了轴的运动和减少可行的工具的环。操作员使用操作员界面（通常是触摸屏）来设置一系列坐标，以定义工具运动。

This is particularly effective and efficient when the tube end has a dimple from a previous cutoff operation; when the tube end is significantly out-of-round after bending; or when the finished size is actually very close to the raw tube size (a case when the amount of expansion or reduction is too little to overcome the material’s elasticity and the tube is likely to spring back to its original size after forming).

在这些情况下，操作员计划在产生最终末端形式之前实现中间部分尺寸的几个命中（协调的工具运动）。在凹坑的情况下，第一次命中可能是过度X和管末端的操作略微向后移除凹坑。下一个击中可能将过度的管子终止到目标尺寸。类似的方法适用于上述其他场景。

In addition to the multiple-hit capability, CNC enables more precise adjustments to any specific end-forming program and typically offers a quicker overall setup process.

在手动I / O尺寸中，操作员可以设定接近开关以定义液压缸的行程，从而定义在成形过程中的管芯和打开的闭合量。一些系统使用硬盘和定时器来停止圆柱体的前向动作，使其缩回。定时器可以比接近开关更精确，更简单，但它们会在液压系统上放置更多的磨损。手动I / O尺寸没有CNC机器的多次命中能力。

两个例子

While end forming isn’t suitable for every component, two projects that worked well for end forming were aftermarket exhaust pipe tips and a rail made from rectangular tubing.

排气提示。This particular aftermarket exhaust pipe tip was two parts made from polished 409 stainless steel—one was 4 in. diameter and the other 3 in. diameter. The outlet end was cut at approximately 45 degrees and rolled in (see图3）。

Manufacturing is increasingly seen as a competitive weapon in the automotive aftermarket parts business, and ram forming offered enticing benefits. The potential for removing one part and one step suggested a lower cost, shorter lead times, and more consistent part dimensions and appearance.

与客户的一个谈判点是部分轮廓末端形成的变化所需的两个直径之间的较长过渡角。客户批准，现在的零件是在两步过程中形成的。因为管壁薄（0.050英寸），导向是使成形工具与夹紧模具保持在中心线上。

使用与RAM工具更换器的机器将其更加优化为一步过程。即使没有RAM工具的选项，制造商也可以通过将零件的数量从两到一，制造步骤从三个到两个，从而做出了很大的改进。

Tubular Rail Assembly。Another application used segmented tooling to form a rectangular tube end for a slip-fit assembly. A series of three of these tubes (1 in. by 3/4 in. by 0.80-in. wall thickness) fit together to form a straight rail approximately 90 in. long. The swaged ends had to be aligned with the length of the tube so the resulting assembly was a straight rail.

The vendor specified this as a ram-forming application, which made for a clean-looking reduction. The end form was a rectangle, just like the unformed portion of the tube. However, the tube had a weld seam along one of the short sides, and the ram forming process did not compensate for spring back. The ends were crooked and the rail assembly was not straight.

现在，I/O Sizer扭动了管子并控制弹簧，从而导致直管。分段模具将管子挤压在OD上，并自定义插头形成ID。末端形式不是矩形（请参阅图4）。当将零件从一种制造方法转换为另一种制造方法时，这是一个典型的权衡。该部分看起来不一样，但其功能有所改善。

This illustrates the need to find out what the part does, how it does it, and which part features affect its functionality versus those that are merely cosmetic. After determining these factors, you’re ready to explore alternative manufacturing methods.