Principle of roller straightening
Contact us to discuss your requirements of Cross Roll Type Tube Straightening Machine. Our experienced sales team can help you identify the options that best suit your needs.
1. Metal sheets up to more than 50 mm in thickness and metal strips down to the thinnest sheets are straightened in straightening machines before further processing.
2. The sheets are subjected to a process of bending back and forth between rollers arranged as shown above with decreasing curvature.
3. The number of straightening rollers depends on the required straightening result.
4. Hardest to straighten are sheets that have unevenness not only in the rolling direction, but also transverse to it. In this case at least one precision straightening machine is required and the straightening process may need to be repeated several times to eliminate the multiaxial tension states in the sheet.
5. The best straightening results are achieved on a precision straightening machine designed with extremely limited stretching and equipped with roller deflection.
Straightening machine drive
1. All rollers are driven together by the distributor gear
2. Drive via three-phase motor, which has a frequency inverter as standard equipment. Depending on the application, a servo drive may also be used.
3. Strip straightening machines are constructed with a run-through speed of up to 120m/min for strip supply operation for pressing.
4. Part straightening machines are designed for a maximum of 20 m/min
How can i achieve good straightening result
1. Good initial material
2. The smallest possible straightening roller diameter+ roller distance
If you want to learn more, please visit our website parts of cnc lathe.
3. Straightening machine with low strain and bending
4. At least 9 straightening rollers to straight coil curvature
5. At least 15 rollers for flat straightening, optimally 19/21 pieces
6. Straightening rollers must be supported
Accurate measurement depends on first identifying a datum&#;an imaginary line between the two pipe ends. The most common and simplest method is to attach a strong, lightweight wire or string to both ends of the pipe, resulting in a taut line stretched between the pipe ends (Figure 3), and measure the difference between the length of the pipe and the length of the line. Although this method is common, in pipes longer than 12 meters, line sag or air movement can be problems. In such cases, laser, collimator or telescope sensors are used.
Heavy-duty pipe straighteners are available to straighten up to 16-inch diameter pipes, having up to 38 mm wall thicknesses. The drive system for such large machines is about 400 hp.
Béla Lipták / [ protected]
A2: Achieving straight tubes is a function of regulatory control with the obvious target of getting zero curvatures. Your problem may require a complex, multivariable regulatory control solution, which may or may not be easily available. If the regulatory control you have is insufficient, it can be complemented with intelligent supervisory control that learns from operating data. For your needs, it could be configured to make adjustment decisions to achieve your objectives (feed-forward), assuming everything of interest is readily measured.
Carlos W. Moreno, Ph.D., CEO and founder, Ultramax Corp. / [ protected]
A3: Every control loop requires a sensor and an actuator, as well as a controller. So, how do you sense a pipe that is untrue? How do you adjust the rolls now? Manually?
Do the three adjustable rolls require three control loops, or can it be done with a single sensor and calculated roll positions?
Why do you need to know about bending moments when a controller's job is to reduce the error to zero? Or, is that how you calculate roll positions?
I've got a picture of the basics of the machine, but no clue as to the scale. Are you straightening house water pipes or cross-country pipeline pipes? Is the pipe from a coil or is it nearly straight? How big are the rolls? How fast does the pipe go through them?
The PTC Alliance website answers some of these questions, but not why you'd need to straighten the pipe, unless welding distorts it
If I understand you, this is not a problem that feedback control can solve. You seem to need the equation for how much to bend the tube to get the deformation required to straighten it. As you said, that depends heavily on the properties (and temperature) of the material. I'd have thought that various scientists and engineers would have published enough data, but perhaps it&#;s completely proprietary. Is your empirical data not adequate?
Does the amount of bending vary during a run? The machine as described can only straighten in one direction. Does it require multiple passes? Does the pipe somehow rotate going through?
Having a skew adjustment implies that the rolls are flat, not grooved. That means the machine is for a wide range of diameters, adding further depth to the knowledge required.
Bill Hawkins, Rosemount Controls (retired) / [ protected]
For more main parts of cnc lathe machineinformation, please contact us. We will provide professional answers.