Step-by-step bend strategics for high-range-product workshops

Fig. 1

CAM software development provides workshops with the possibility to gain more effectiveness and productiveness. Step-by-step bend together with off-line programming reduces interruptions, improves part flowing and controls expenses. This advancement in the area of tool technology and CAM programming allow workshops to come up with more excellent performance.

Conventional Bending vs. Staged One.

Workshops with a high range of products cannot be sure about what their next task would be, about the tools required by it. That is why they should possess press brake tools, that are as flexible as possible at any time.

In most cases air-bending provides more flexibility for differently thick materials. This technique makes it possible to carry out a wide range of tasks with a small amount of tools. However, air-bend does not deliver sufficiency to make some needs of customed parts. Certain tasks require bottom bending through paired tooling. And narrow inner radius for certain parts requires large-capacity coin formation. 

Let`s review a rigid computer chassis. It will require bending over 90 degrees for each box corner. Those of fabricators, who will manufacture a chassis accommodating such features as more chips, ventilators, greater storage, are going to benefit. This range of features might demand any type of blinds, flange, off-set, card guide and some other intricate shapes. Mostly, an off-set or flange needs bending and aligning afterwards.

Conventional bend operations are carried out through a setting handled separately for a certain shape. All through the bend operation up to 5 set-ups for the press brake may be necessary. Or otherwise, the task can be completed by using more than one machine. After being bent through a tool-set, the part is passed to the next worker to further on the processing over the next press brake. Each of these two mechanisms has drawbacks. One links more than one worker to the machine, the other demands repeated set-ups of the machine.

The bend process, done step by step, makes it possible for a press brake operator carry out multi-fold bending through just one set-up. (Fig. 1) The press brake frame bears a tool-set alongside, which allows multi-fold bending upon one part made successively. This makes the intricate short-term tasks simple, excluding inefficiency and repetition, considerably decreasing set-up duration, processing of details and work in progress.

Step-by-step bend process demands the press brake tooling to possess an overall shutter height to escape clashes. The first followers of this experience achieved this making use of a range of pads and risers. Yet, this process turned out to be both laborious, and costly. The first endeavor, to realize stage bends, delivered rapid set-up; nevertheless, it was not flexible.

Nowadays most producers provide press brake tools with an overall shutter height built in the machine structure. This offers a possibility of arranging various tools through one set-up with no laborious shim operations. (Fig.2) As the stepwise bend process eliminates ineffective and repeated jobs through an overall shutter height, the whole work process accelerates within the workshop. Besides, this provides more flexibility for the tool stock. 

Fig. 2

Off-line Programming

Imagine you have punched the detail or cut it through laser, and when on press brake it turns out that its formation is impossible as the workshop lacks the necessary tooling. A matter like this will destroy productivity drastically. A pile of details stays on shelves as long as a decision on the right tooling is made. Then rather a long time is required before it is ordered to tooling manufacturers. Only after the tool can the part be bent. Thus, the work process flows inefficiently, which can be avoided through off-line programming and bending simulation.

Computer-aided manufacture software equips press brakes with CNC program, which enables a manufacturer to realize off-line programming and also provides complete three-dimensional model of the bend process. This software is applicable for various kinds of press brake machines and tools. Its design is meant to identify each feature of the machines, meanwhile simplifies the process of selecting tools.    

The software scans the inventory of store tools and makes automatic selection of tools most suitable for the formation of a part through a single installation. It decides on the tooling and where to press them on a press brake. 

Compute-aided manufacture also provides engineers and programmers with feed-back. The software delivers answers to such questions as: Is it possible to form a particular part through a stepwise bend set-up or a multi-fold set-up. Which press brake is the most proper for the task? Can the operation be carried out through a single stepwise bend set-up on long-bed machines? Whether interferences are likely to happen in particular bending sequence? 

Step-by-step bend process rationalizes the whole procedure by making multiple bends through as few tooling set-ups as possible. It arranges the tool-set most efficiently ensuring right bending succession for operators. For example, the 1st bending may demand a tool-set over the left-side, the other bending might demand a tool-set over the right-side, the next one some other tool-set at the central part. In this case operators had better figure out bending succession, allowing operators to use tool arrangement to handle bending efficiently. The software has a significant role in this.

It is possible for a programmer or operator to determine on preferable tools for particular types of material as well as bending radius. Software offers an opportunity to combine progressive formation tasks through a single set-up with coin and air formation. Some thirty or ninety-degree punches and dies can be placed at the special die sets capable of coining and bottoming. For example, operators can perform air-bending of more than one flange and go on to the immediate formation of secure edges through hem dies. And all this through one installation. 

Smart Production Planning 

It is important to determine if parts are possible to form prior to the work releasing. Next step should be deciding on the proper tools. When the off-line bend has been programmed, press brake operators may view the three-dimensional forms of tools at the brake controllers or at an adjoining computer. Then the simulation of formation process can be made to ensure efficiency for the whole bend process: bend succession, clearance, tool positioning, etc.

As soon as the task appears at press brakes, operators get sure about the required tools and their set-ups, and also the perfect bend succession to secure optimum flow of parts. Computer-aided manufacture software, three-dimensional simulation, press brake tool-set all combined provide the whole process with highly efficient outcomes.