TPT March 2009

D rilling, P iercing & P unching T echnology

Expertise in tube punching and drilling technology

With proper tooling, many of the previously mentioned problems can be eliminated or at least minimized. There are several bit profiles available that greatly reduce burrs and speed the drilling cycle. Added to this is tooling designed to stabilize and guide the bit during the drilling cycle, which leads to higher accuracy. As with the punching process, it is advantageous to index the tube under the fixed position of the drill. Both manual and automatic equipment are produced for making accurate linear and radial indexes. Manual style punch machines rely on an operator to make the different stops at each pattern location and to cycle the punch at each stop. A manual machine is relatively inexpensive and can be customized for a wide variety of tube materials, shapes, and sizes. Automatic machinery that is built for this process relies on a servo based positioning system that is driven by a part program to make the intended pattern stops and to cycle the punch at each stop. While an automatic machine of this type is more expensive, it makes up for the added cost with increases in speed, accuracy, and efficiency. An automatic machine is also better suited to producing complicated patterns that contain many linear and radial locations. Machinery for either process should be simple to set up and provide a fast, accurate method for getting from one hole to the next. A hole making machine must be rigid and provide nearly perfect, repeatable alignment between the tool and the hole – especially when mandrel punching. The choice for machinery and tooling, and ultimately the hole making process, can be a difficult one. Punching and drilling are virtuous because they are simple processes and offer a very low cost per hole. There are limitations to each, but with a good part design that is based on the processing method, most limitations can be overcome. Carson is the manufacturer of a line of hole punching equipment for the production of header tubes. These machines come in two basic versions, manually operated and semi- automatic. The company also offers a range of equipment for bending, end forming, end closing and other special machines. Carson Engineering & Mfg – USA Fax : +1 479 751 2834 Email : info@carsonengineering.com Website : www.carsonengineering.com

When faced with the task of producing a pattern of holes in tubing, there are many different options to consider. There are mandrel punched holes, mandrel-less punched holes, drilled holes, milled holes, pulled (or collared) holes, and others. For most applications, the best options are mandrel punched holes or drilled holes. Mandrel punching is generally favoured over any other because it is clean, accurate, and fast. This process utilizes an internal die or mandrel, an external punch, and a tube support. When tooled properly, a mandrel punched hole is burr-  Mandrel punching is generally favoured because it is clean, accurate, and fast

free and creates very little distortion to the tube’s original shape. As an added bonus, the waste that is produced is a slug that is easily evacuated from the point of operation and gathered for recycling. Another advantage of the mandrel punching process is that it allows for the punching of different shapes. This ability is essential to many applications. The preferred method for producing a pattern of holes with this process is to index the tube over a fixed mandrel. This method allows for a very accurate punch to mandrel alignment, which is essential for maintaining the quality of the punched hole. There are situations where a mandrel punched hole is not an option. These include cases where it is impossible to insert a mandrel due to a feature of the tube and, more commonly, the case where the hole size is too near the inside size of the tube. In this case, a mandrel would be too fragile for practical use and would not allow the necessary clearance needed for slug evacuation. When these situations arise, a drilled hole is a very good option. The main drawbacks normally associated with drilling are burrs around the hole, chips, and a reduced rate of production compared to punching. There is also the fact that a drill can produce round holes only.

Special robot loading device for punching lines Apollo, Italy, has introduced a robotic loading device that works in unison with the company’s Twin punching lines. The robot device can load and unload workpieces from dedicated containers to the machine and back again. This robot considerably lowers working time and labour. The robot can simultaneously load two punching lines or take the cut material from a sawing machine coupled with an Apollo punching machine. The time for loading and unloading is approximately 6 seconds. The punching line features remain the same, as the coupling with the robot does not involve any technical change. Apollo can provide customized solutions in order to transform all of its punching lines into fully automatic machines. Alternatively, the company can provide the robot coupled with the new punching machines. Apollo may also be able to supply overhauled robots of the KUKA and ABB brands. Apollo – Italy Fax : +39 0536 851273

Email : info@apollosrl.com Website : www.apollosrl.com

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M arch 2009

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