The Basics of a Straightening Machine
Straightening machine are used to correct the shape of rolled, drawn or extruded metals. They are often employed in the manufacture of automotive and aeronautical components, such as body panels and engine cylinders. However, these machines can also be used to straighten other products made from rolled or drawn metals, such as pipes and rods. Depending on the material used, there are several different types of straightening machine to choose from. They are available in both manual and powered versions. Each type has its own unique set of advantages and disadvantages.
Manual pull-through straighteners use the force of a feeder to drag the metal through the rollers. While these machines can be less expensive and take up less space, they suffer from inertia, which leads to inconsistencies in the resulting straightness of the material. This can lead to marking or even broken work rollers, especially if the straightener is required to process materials of varying widths and thicknesses. Powered straighteners, on the other hand, utilize a set of driven rollers to move the metal through them, and they can be much more effective at removing coil set.
In order to achieve consistent and effective results, a straightening machine needs to be properly specified and configured for the application at hand. The combination of pinch roll pressures, the drag brake strength and the work roller depth settings will all affect how well a straightening machine performs. In addition, the maximum width of the material and the machine itself must be taken into account.
The amount of metal that can be straightened with a given machine depends on the material’s yield point. Various metals have different yield points, which means that they will require different amounts of bending force to be straightened. In addition, the thickness of a piece of metal also affects its need for bending forces, since a thicker piece will require larger-diameter work rollers than a thinner one would.
Generally, the higher the number of straightening passes, the better the quality of the finished product. This is because additional passes increase the bending forces, and therefore the amount of straightening that can be accomplished with a particular machine.
A common technique to improve the quality of a straightened product is to use a second set of working rollers that are smaller in diameter than the first. This reduces the deflection of the material and makes it possible to achieve better straightness tolerances with a single pass through the machine.
Most straightening machines have a set of back-up rollers that are positioned on either side of the main work rollers. The purpose of these back-up rollers is to provide additional support in the event that the main work rollers are deflected too much. This is a common problem in many types of straighteners, and can result in reduced straightening quality or even damaged work rollers. The best way to avoid this problem is to ensure that the ‘zero’ position of the work roller depth setting, or the amount of penetration (distance from the bottom of the lower fixed roller) is set correctly.