The word “hybrid” sometimes brings to mind two separate systems being used to do a single job, as in a hybrid car that has both a gasoline engine and a battery drive. That’s one way to use two technologies. Another, higher level is to fuse the best of both technologies into a complete system, and that is the case with AMADA’s Hybrid Drive Technology.
This servo motor/hydraulic drive system is available in two lines of the company’s press brakes. The combination drive achieves impressive results in performance and resource utilization. Some of the advantages of this technology include:
Before we explore more about these advantages, let’s take a closer look at how design affects technology. Figure 1 gives us a look at the newly designed hybrid system offered in the HG press brake series.
Clockwise from the top, we start with the pressure tank which holds pressurized hydraulic fluid and imparts pressure to the cylinder to move the upper table downward.
A separate hydraulic line connects the AC servo motor to the cylinder, which assists in this initial motion. Two mechanisms move fluid at this point.
Figure 2 shows how the system works in the rapid lowering phase as described above. The pressure tank and the servo motor combine to load the cylinder with fluid very quickly, prompting a rapid lowering of the upper table.
Once the press brake tooling approaches the part to be bent, the system changes to a bending process as shown in Figure 3. The pressure tank is no longer supplying pressure to the cylinder; the work is being done by the rotation of the servo motor. The faster the rotation, the higher the tonnage.
Finally, when the bend is done, the upper table returns to the top using the method shown in Figure 4—essentially a reversal of Figure 2.
There are a lot of differences between the Hybrid Drive System and the older, traditional hydraulic systems. The most noticeable difference is in its use. The system comes online when we start a bend (with older technology, the system continues to run between bends). The brake does not run until you hit the foot pedal.
One of the time-saving features that comes from the Hybrid Drive System design is that the upper table comes down very quickly until it gets near the bend point. This saves a lot of time over the course of the day and increases parts per hour.
When the upper table is almost at the bending process, the servo motor provides the downward motion (reference Figure 3). As the bend takes place the tonnage used in the bend is regulated by the speed of the motor’s rotation. The speed of rotation is managed with extreme precision. Because the servo motor’s rotation can be so finely controlled, the ram position is incredibly accurate and the repeatability is 0.00004”.
Cleaner, greener, and cooler
Traditional systems use a single, shared hydraulic system to supply both cylinders with fluid. That means many feet of hoses to fill in order to distribute the hydraulic fluid across both systems. With the hybrid drives, each with its own fluid supply in a closed system, it uses about four times less fluid than a traditional system—less than 15 gallons vs. a shared hydraulic system’s 55 gallons. That means less cost to change the fluid, and less cost and preparation to dispose of the spent hydraulic fluid.
Furthermore, hydraulic fluid has a tendency to heat up when it is cycled through pressure states. The hybrid drive system’s smaller, separate tanks are much better at dissipating heat than the combined, connected system. The fluid in turn has a longer life in the system. A more stable fluid temperature means a more consistent fluid viscosity, which correlates to a highly accurate and stable bending process.
It is easy to see the benefits of an on-demand system. One other side benefit related to the lower energy use of a hybrid drive is that the noise is noticeably lower, a plus for the shop floor and your press brake operators.
With no compromise on tonnage, fabricators save electrical costs (the hybrid system operates only as needed) as well as costs associated with hydraulics (less fluid, longer life, less hoses, closed system). The amount of energy consumed by the actual machinery in a hybrid system between bends is zero.
Between the on-demand nature of the hybrid system, and how it changes its power source in the bending process, means that the Hybrid Drive System achieves savings of about 80 percent in power consumption.
The Hybrid Drive System certainly looks to the future, but is available now and is standard in both the AMADA HG Series and HRB Series press brakes.
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