The development of the first strip thickness gauge worldwide, that could measure the thickness of the strip during the rolling process in cold mills with an accuracy of µm, was the start of our company in 1963.
Vollmer America
March 2004 Newsletter
Integrated construction
Shapemeter Roll with Laserspeed
When space is precious, as it was in this application, the Vollmer shapemeter roller brings its narrow construction to bear as an unique advantage.
This Vollmer shapemeter roll (BFI-system) in combination with a water-cooled laser strip speed gauge is the basic item for the modernisation of a 20-roll cluster mill, which had already been upgraded with a Vollmer strip thickness control a number of years ago.
The present modernisation includes two additional VBM 1076. Together with the two previously installed VBM 1076 thickness gauges, they now form two pairsof tandem gauges. They measure the very thin copper strip rolled in this mill with optimal accuracy.
These are the strip data:
Thickness 0,045 to 2 mm
width 660 mm
strip speed 400 M/Min.
An essential element of the Vollmer strip shape control is the optical strip edge detection by electronic line cameras. It allows the utilization of all measurement data from the shape roll, even those data created by the sensors measuring the strip edge. Without edge detection, this data used to be left out, because the system could not determine wether a sensor is completely covered by strip under moderate tension or if only a small portion of it is covered by strip under high tension. This is important for two reasons: Too loose edges result in a larger amount of off-spec strip material that has to be cut off, and they may cause a curvature of the inner strip section. Too tight edges on the other hand tend to cause strip breaking. Therefore, our strip edge detection decreases the downtime and increases the output especially when looking at older mills where the strip tends to run away
laterally during the rolling.
The shapemeter roll is driven by a timing belt. The shapemeter roll itself drives a tachometer (not installed in the photo) by a second such belt. Its signal is used for the automatic thickness control. An additional rotary incremental encoder is installed in the operator’s side bearing of the shapemeter roll. It is used as a safety backup for the mass-flow system’s strip speed measurement.
Standard Connector Bridges now integrated at the factory
VMF 2000 Wiring Alterations
So far, a number of contacts in the I/O interfaces X7 andX8 of the VMF 2000 measurement amplifier have been bridged externally. The short-circuit bridges were soldered into the connector plug of the extension cable to provide power and ground to the opto-isolators.
Beginning with the production number 2138, those bridges are now integrated into the VMF 2000. The collectors of the outputs and the cathodes of the inputs of the two interface sockets X7 and X8 are bridged internally as stated in the following:
X7: 19-20-21-22-23-24-25-26-27-28
X7: 30-31-32
X8: 19-20-21-22-23-24-25-26
X8: 27-28-29-30-31-32
It is still possible, to connect those interfaces with the internal voltage supply or with an external voltage supply. However, never connect both kinds of voltage supplies, this will cause severe damage!
In standard applications, old VMF 2000 amplifiers can simply be replaced with new VMF 2000 amplifiers. It does not matter, if the bridging is repeated in the plug of the connection cable.
In special applications however ( such as tandem thickness gauges ) the nominal size signal from the VMF of the working gauge is passed on to the VMF of the control gauge. In such cases, different bridges are required. Therefore, amplifiers in such applications need to be replaced with specially prepared amplifiers, otherwise damages might occur.
New VMF 2000 amplifiers from production number 2138 may be replaced with older VMF 2000 amplifiers only after the required bridges were soldered into the cable’s connector plugs.
Multiple Measurement Tasks
Gauge for Truck Chassis Beams
This gauge was custom-designed for one of the largest German truck manufacturers. It measures continuously the U-shaped profile at the outgoing side of a shaping line. In this line, 4 to 10mm thick strip is rolled off a coil and then continuously bent to form an upside-down U. At this stage, the profile passes through the gauge before it is automatically cut to the desired length. Right after the cutting, all the required holes are punched into the chassis beams.
The gauge measures the width of the profile’s back (200 to 340 mm), the height of its side walls (70 – 100 mm), their squareness to the back, the arch measured across the back, and the twist of the back.
Since the massive power input in the shape line produces some debris on the profile’s surface, the gauge was designed so that all sensitive parts are situated above the profile to protect them from being blocked by dirt deposits. The frame with the entire center gauge can be moved off line in a long roll guide system. The two height gauges pull off the line to opposite sides of the profile, each in its own slide base.
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VIP 08 Flatness Measurement System
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Quality and Yield Optimization on Cold Rolling Mills
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News & Events
BFI Article shows new design for shape roll measurement
The well-proven BFI version shape measurement roll has undergone a design change that improves its ability to measure the tensions profile on flat product without marking the strip. The detectors have been redesigned to fit into the roll while leaving the surface of the roll completely clear of machined marks. This eliminates the former problems associated with the axially installed sensors.