Rolling elements integrated into bolsters and feeding devices make smooth pathways for quick die change. Considering the size and weight of the die as well as economic and application-dependent aspects, there are different ways to implement efficient rolling.
Various dimensions and capacities
Custom manufacturing, adapted to your standard DIN 650 or special slots
Standard working temperature up to 70 °C, 160 °C with Viton seals
Balls
Ball cartridges and ball bars
Allows flexible and highly accurate positioning. The die
can be moved in any direction and at any angle. This is
useful for smaller dies that are positioned manually (< 2 t).
Balls
– Multi-directional movements
– Low rolling resistance with a coefficient of 0.15 up to 0.2
Hydraulic
– 100 bar
– G1/8 (BSPP) or UNF 7/16 connections
Rollers
Rollers cartridges and rollers bars
Allows only forward and backward movements.
Positioning accuracy is ensured by using guides and/or a loading device, such as our Push-Pull System (PPS).
The load capacity is much higher (> 2 t).
Rollers
– Single-direction movements
– Very low rolling resistance with a coefficient of 0.07
Mechanical
– Spring washers “Belleville”
Rolling on roller bearings
Is possible with some of our roller bars, which can also be furnished with antifriction bearings for an even lower rolling effort. These bearings are also available in waterproof and dustproof treatments. A SERAPID Push-Pull System, is strongly recommended.
These are used for positioning the die in front of the press or to bridge gaps between the bolster and a die cart. They are used to fill the gap between the press and the rail-mounted carts or shuttles. Our bolster extensions are equipped with large rollers so that the tool rolls smoothly and without shock. Rolling bolster extensions are compatible with bars and T-slots (DIN 650).
They are available in different versions: swivel, mobile, removable. All consoles can be equipped with sliding hooks, feet, extensions if needed. Legs and floor rollers are also available for easy deployment at different presses.
Specifications
Screwed construction with mainly aluminium bolster sides
Hardened steel rollers on friction pads
Retractable stopper provides a fall safety mechanism for the die
Especially adapted for manual die positioning
Manufactured to order with special dimensions
Depending on the size and the degree of automation of your QDX system, you may choose between two options, pump or power pack, for driving hydraulic units.
Hydraulic rollers and hydraulically opened clamps
They require only one hydraulic circuit, which is used occasionally. Thus, for a limited number of bars and/or clamps, the easiest and most cost-effective solution is a manual pump. We offer a ready-to-install pump kit. For more hydraulic units, and particularly for our LGGH heavy-duty roller bar, we recommend an airdriven pump.
Clamps with hydraulic closure
It requires control of output power for closing, and therefore a regulated power pack and a directional seated valve bank. Our clamping power packs work in watch mode. Once
the working pressure has been obtained, the power pack stops output and restarts only to compensate for pressure drops. A pressure-monitoring switch has to be integrated in each clamping circuit, to stop the press, if any of the clamping devices receive less than
80 % of the pressure setting.
External hydraulic sources may be supplied by the user under the following conditions:
oil type HLP 32 or 46 Cst is used
output is regulated and protected by a pressure limiter
flow rates from 0.8 to 4 l/min available
the valve bank has to be a ball-type design with a non-return valve at the bottom of the column
FAQ
Always. Although it is possible in some cases for the die to simply slide across the bolster (steel / steel), more frequent die changes require a smoother running system. Damage to the bolster and die, time lost with difficulty in positioning dies, higher energy consumption are all factors that can cut down on profitability. Rolling elements, by contrast, ensure optimal operation at one-time-only cost.
Rolling elements should be used for any tool over 2 tons.
For dies above 10 tons, heavy-duty bars, in special slots, should be used. If this is not possible, fixed rollers should be installed on the loading console or staging table outside the press to minimise the risk of shocks.
Using balls the rolling friction depends chiefly on the hardness of the surface.Friction coefficient between 0,15 and 0,2. With small rollers (Ø < 30mm), the friction coefficient typically lies 0,07.
HOW TO CHOOSE ROLLING ELEMENTS?
Balls and rollers are lifted either mechanically or hydraulically. Springs press the rolling element against the die permanently, even when it is clamped down. Hydraulically lifted rolling elements, in contrast, retract to their resting positions when the pressure is released.
Our rolling elements are available in bars that fit into standard or special slots in the press bolster, or in separate cartridges that can be installed in any desired arrangement.
Our rolling bars are available in DIN 650 sizes from 18 to 36. To be safe, always check the true dimensions of the T-slots in the press bolster. Specific manufacture on request.