| Type | Roller diameter | Strip thickness mm | Number of rollers | Standard strip widths | Support | |
|---|---|---|---|---|---|---|
| mm | min. | max. | pieces | mm | ||
| 10 | 10 | 0.1 | 0,5 | 19 | 120, 220 | Support rollers |
| 12 | 12 | 0.2 | 1 | 19 | 120, 220 | Support rollers |
| 15 | 15 | 0.3 | 1,2 | 19 | 120, 220 | Support rollers |
| 18 | 18 | 0.3 | 2 | 9 / 19 | 160, 320, 420 | Support rollers |
| 24 | 24 | 0.4 | 3 | 9 / 21 | 220, 420, 520 | Support rollers |
| 30 | 30 | 0.4 | 4 | 9 / 21 | 220, 420, 620, 820, 1020, 1320 | Support rollers |
| 40 | 40 | 0.5 | 5 | 9 / 11 / 21 | 220, 420, 620, 820, 1020, 1320, 1520 | Support rollers |
| 50 | 50 | 0.6 | 7 | 9 / 11 / 21 | 220, 420, 620, 820, 1020, 1520, 2020 | Support rollers |
| 65 | 65 | 1 | 10 | 9 / 11 / 21 | 420, 620, 820, 1020, 1520, 2020 | Support rollers |
| 80 | 80 | 1,5 | 18 | 9 / 11 / 21 | 420, 620, 820, 1020, 1520, 2020 | Support rollers |
| 100 | 100 | 2 | 26 | 9 / 11 / 21 | 420, 620, 820, 1020, 1520, 2020 | Support rollers |
| 130 | 130 | 3 | 38 | 9 / 11 / 21 | 1020, 1520, 2020, 2520 | Support rollers |
| 160 | 160 | 5 | 56 | 9 / 11 / 17 | 1020, 1520, 2020, 2520 | Support rollers |
| 200 | 200 | 3 | 65 | 9 / 11 / 15 | 1020, 1520, 2020, 2520 | Support rollers |
9-roll straightening machines
are used to remove coil curvature. This requires that the curvature of the coil is constant over its entire length.
If this dimension changes - for example, due to increasing curvature toward the center of the coil - the straightening machine must be readjusted accordingly.
Consistent straightening quality from the outer diameter to the inner diameter of the coil cannot therefore be achieved throughout.
Furthermore, this straightening principle does not reduce any internal stresses in the material.
21-roll straightening machines
are designed to straighten the starting material with maximum precision – regardless of the extent of the coil curvature. Even complex alternating bends are reliably compensated.
A decisive advantage of these precision straightening machines is the effective reduction of tension in the coil material. This improves the flatness of the strip and considerably facilitates downstream processing steps.
Straightening result
In order to achieve a perfect straightening result, the material to be straightened must have uniform strength across its entire cross-section. Edge waves or dents can only be compensated for within the limits of physical possibilities.
An effective straightening process is only possible if the material in the straightening machine is stressed beyond its elasticity limit. If the load remains below this limit, the material returns to its original state after passing through the machine - straightening does not take place.
The actual straightening process takes place in the stress range between the elasticity and yield limits. If the yield limit is exceeded, the material begins to stretch permanently.
Sheet metal plates with thicknesses of over 50 mm and sheet metal strips down to the thinnest foils are processed in straightening machines before further processing.
he material is bent back and forth several times between the straightening rollers, with the curvature decreasing steadily. The arrangement of the rollers and their number depend on the desired straightening result. Straightening sheet metal that has unevenness both in the rolling direction and perpendicular to it is particularly challenging. In such cases, a precision straightening machine is required. If necessary, the straightening process must be repeated several times to completely eliminate the complex, multi-axis stress states in the material.
The best straightening results are achieved with precision straightening machines that are designed to be particularly low-strain and have roll deflection.
LORENZ straightening machines are characterized by their high bending and tensile stiffness.
Their development is based on over 60 years of experience - for maximum precision, process reliability, and dependability in daily use.
Continuous straightenin
In continuous straightening, the actual material thickness is set at the machine outlet, while the material thickness minus the feed is specified at the inlet. The required setting values are either calculated automatically by the comfort control or can be taken from the corresponding feed diagram.
In this process, the material is straightened in the direction of travel. The straightening process itself takes place in the stress range between the elasticity and yield limits. If the yield limit is exceeded, desirable plastic deformation of the material occurs.
Edge straightening
In this type of straightening, the strip is additionally straightened in the direction of the sabre. This effect occurs by clamping the strip before and after the straightening machine. The upright straightening unit located at the outlet is moved out of the middle for this purpose. However, the actual edge straightening effect occurs in the straightener, as the material is in the plastic range there.
Straightening machines Roll diameter 10 - 65
Material strength 500 N/mm2
Straightening machines Roll diameter 80 - 200
Material strength 500 N/mm2
Standard gearbox
The gearbox has a single-stage / two-stage design and distributes the drive force evenly to all straightening rollers. All gears are case-hardened and completely ground. They also run in needle bearings. The gearbox is oil-filled and not connected to the recirculating oil lubrication system.
Gearbox High-performance straightener
The gearbox has three stages and distributes the drive power evenly to the drive shafts via special gears. Power is transmitted via profile teeth, which significantly increases the torque that can be transmitted. All gears are case-hardened and completely ground. They also run in needle bearings.
The gearbox is filled with oil and is not connected to the oil circulation lubrication system.
This significantly increases the service life and alignment capacity of the machine.
Standard cardan shafts
The cardan shafts essentially consist of 2 ball joints, which are equipped with a length compensation.
Power is transmitted to the gearbox and straightening rollers via pins.
High-performance cardan shaf
The cardan shafts made of special material essentially consist of 2 ball joints equipped with length compensation.
Power is transmitted to the gearbox and the straightening rollers via splines.
Drive
The drive is provided by a maintenance-free three-phase motor that is controlled by a frequency converter. Power is transmitted from the motor to the gearbox via belts to absorb shocks caused by the straightening process.
A current-dependent overload protection protects the machine from excessive loads.
Pull off
The pull off is equipped with two hardened and ground rollers. The upper roller is fed by pneumatic/hydraulic cylinder, whose contact pressure can be adjusted by a pressure control valve.
The contact pressure must be adjusted to accommodate different material thicknesses.
Pull off with extended functionality
The pull-off is equipped with two hardened and ground rollers. The upper roller is fed by a pneumatic/hydraulic cylinder, whose contact pressure can be adjusted by a proportional pressure control valve.
The contact pressure must be adjusted to accommodate different material thicknesses.
The set pressure is stored in the tool data memory.
Standard strip side guide
There is a strip side guide on the infeed side, which consists of 2 horizontal deflection rollers + 2 vertical side guide rollers. The vertical guide rollers can be adjusted centrally via a spindle. The setting values can be read digitally on a counter.
All rollers are hardened.
Motorized belt side guide
There is a belt side guide on the infeed side, which consists of 2 horizontal deflection rollers + 2 vertical side guide rollers. The vertical guide rollers can be adjusted centrally by motor.
The setting values can be stored in the tool data memory.
All rollers are hardened.
Manual roller frame adjustment
The complete upper roller frame is adjusted by 2 handwheels, which adjust the height of the machine infeed and outfeed. Normally, the material thickness of the material to be straightened is set on the outfeed side. On the infeed side, an infeed is selected that is below the material thickness. The corresponding setting values can be taken from the infeed diagram supplied.
The machine setting is measured using two digital sensors and can be read on the control panel. The reading accuracy is 0.01 mm.
Motorized roller frame adjustment
The complete upper roller frame is adjusted by 2 spur gear motors, each of which adjusts the height of the machine infeed and outfeed. Normally, the material thickness of the material to be straightened is set on the outfeed side. On the infeed side, an infeed is selected that is below the material thickness. The corresponding setting values can be taken from the infeed diagram supplied.
The machine setting is measured using two position sensors. The reading accuracy is digitally 0.01 mm and can be read and saved on the control panel.
Quick-change device extended
The entire straightening roll bearing is mounted on a sliding plate.
This sliding plate, on which both the straightening rolls and the entire support are mounted, can be extended so that replacement can be carried out quickly at an easily accessible location.
An additional bearing point mounted directly on the roll stand on the gear side accommodates the so-called driver and fixes the drive shafts when the straightening cassette is extended. This means that the drive shafts do not need to be detached for machine cleaning.
Standard quick-change device
The straightening roll bearing is mounted directly on the roll stand and is supplemented by an additional bearing on the gearbox side.
As with the quick-change device, a so-called driver is located between this bearing and the gearbox-side bearing of the straightening rolls, which securely fixes the drive shafts when the rolls are pulled out.
The basic design of the bearing is the same as that of the quick-change device. However, with this design, it is not possible to remove the rolls, including the bearing, from the machine.
The intermediate rollers prevent the support rollers from being imprinted on the belt to be straightened. This effect occurs because the straightening rollers are smoothed at the points where the back-up rollers run. This different surface roughness is visually reflected on the belt.
Stripes appear, which also reappear when the belt is subsequently coated. The intermediate roller diameter is always kept smaller than the straightening roller diameter. This achieves an additional cleaning effect.
A 9-roller straightening unit is mounted on the inlet side of the straightening machine. A second straightening unit with 4 rollers is located on the outlet side.
The upright straightening device on the inlet side is adjusted using two hand wheels.
The outlet side can be adjusted centrally to the strip width using hand wheels and can also be moved off-center.
This arrangement effectively minimizes the camber in the strip.
Standard insertion aid
The insertion aid is designed as a compact unit and is located directly in front of the belt puller.
Insertion wedge from below
The infeed wedge, which is hydraulically adjustable in length and inclination, takes the strap from the coiler and transfers it to the straightener.
Hold-down roller from above
With the help of the hydraulically operated hold-down roller, the coil bend at the start of the strip is pressed smooth so that the strip can be driven into the strip take-off mounted directly in front of the straightening machine.
Universal feed aid
The insertion aid is designed as a compact unit, is located directly in front of the strip take-off and has the following features:
Insertion wedge from below + above
The infeed wedge, which is hydraulically adjustable in length and inclination, takes the strap from the coiler and transfers it to the straightener.
Hold-down roller from below + above
With the help of the hydraulically operated hold-down roller, the coil bend at the beginning of the strip is pressed smooth so that the strip can be driven into the strip take-off mounted directly in front of the straightener.
Pressure arm from above
The pressure arm, which acts from above, is hydraulically operated and reliably prevents the coil from springing open when the bandages are opened – and the associated risk of injury. Both the speed and the contact pressure can be individually adjusted.
When the strip is rewound, the pressure roller acts as a brake, and when it is wound up, tension is applied to the material in a targeted manner. The roller is driven, enabling both the strip start to be advanced and the strip to be rewound.
The arm width is at least 80 mm. In conjunction with the start-up and counter-holder rollers, the arm width is approx. 160 mm.
This results in a minimum strip width of 80 mm with the standard coil guide and 20 mm with start-up and counter-holder rollers, which can be threaded with the pressure arm. The arm itself is firmly mounted on the housing of the straightening machine.
The hydraulic cylinder is equipped with seat valves which maintain the pressure in the cylinder in the event of a hose rupture, thus providing additional safety.
Pressure arm from below
The pressure arm, which acts from below, is hydraulically operated and prevents the coil from springing open when the bandages are opened, thereby avoiding potential hazards. Both the speed and the contact pressure can be individually adjusted.
When the strip is unwound, the pressure roller acts as a brake, and when it is wound up, tension is applied to the material. The driven roller also serves to advance the start of the strip and to wind it back.
The arm width is at least 80 mm. In conjunction with the start-up and counter-holding rollers, the arm width is approx. 160 mm.
This results in a minimum strip width of 80 mm for the standard coil guide and 20 mm for the start-up and counter-holding rollers, which can be threaded with the pressure arm.
The pressure arm is permanently mounted on the housing of the straightening machine.
The seat valve mounted directly in the hydraulic cylinder provides additional safety. This reliably maintains the pressure in the cylinder, even in the event of a hose rupture.
