Forming proper pieces through press brakes depends on various factors. Yet, these following are the most essential ones to be considered by operators:
They play unprecedented role in the whole process, accordingly they should be skilled, be consistent in the professional development to keep up to date with modern technologies.
All the rest mentioned above factors have to be taken into consideration by them as well and be applied wholly to provide precise work pieces in optimal duration. The task of an operator is to produce high-quality parts and to minimize setting duration within the limits of a particular machine.
Minimizing setting duration is crucial and the experienced operator is able to decrease it on the particular press brake.
Operator has to consider the interrelation of setting time and the piece amounts manufactured, which helps to take into account the setting duration on time for the part manufactured.
In case of a short run tunning duration must be as least as possible in comparison with a long run of complex pieces. Ordinary pieces that require less tunning time have to be produced with little quantity, whereas coplex pieces requiring long tunning must be produced with large quantity. The operator bears responsibility for making decisions like that, and some experience is needed to come to a proper solution.
Combining Experience with Machines. Previously workshops used to make use of hydraulic or mechanical press brake machines. These two used to require longer setting time, and it was an effective option to produce large numbers of pieces.
With consiquent establishment of modernized CNC, later CNC press brake machines, setting duration was significantly minimized, and the experience required by the operators altered. Setting up and operating a modified CNCs or fully CNC brakes require a new extent of practice or awareness comared to handheld (non-CNC) setting and operating of brakes.
Consequently, the existing brake design defines the necessary extent of opeerational experience and the outlet of molded pieces. Operators skilled in working with non-CNC brakes should be fully trained to work with CNC brakes. Operators should know the equipment, its restrictions quite well.
Restrictions: Different brakes have got different fortified utmost load in tonnage for each inch at the middle of the equipment. Increasing tonnage limits may cause damages to the brake, tools and molded parts.
For instance, applying entire shipload of 600 tonnage brakes upon eight-inch parts at the machine middle may cause serious ram constant deformity in its centeral part.
For determinning tonnage for each load range, the side-frame distance should be multiplied by 60%, the result get devided in the equipment shipload. Say, in case of a 150 tonnage brake and sidframe distance of 10ft., 120 inches should be multiplied by 60% and the outcome is 72 in. Then deviding 150 tonns into 72 in. and the range will be 2,08 ton for each inch in case of the particular equipment. Consequently, it is preferable not to exceed 25 tones for each 12 inches.
It is important that operators calculate the utmost limited load in piece formation process prior to realising the first bending. This is especially essential for bottom-bend and coin procedures. Load limits cannot be exceeded in the air bend process. Just in case of bottom bends and coin procedure tonnage may surpass the equipment load rate. Load limitation figures may be obtained from the manufacturer. Besides, they are attached to the backside of the equipment. Yet, those load figures are intended in case of air-bend operation. For bottom operation tonnage air-bending load muat be multiplied by 4, and by 8 in case of a coin operation.
Formation of parts off the centre is preferable from time to time if the brake machine design allows it. Otherwise, serious damage might be caused to the equipment.
Maintenance: An operator has to be aware of maintenance tips, which imply changing of oil and filters in case of hydraulic equipment, lubricating regularly. These may not be carried out by the operator, yet, he must have awareness of all this.
Operators have to master air-bend, bottom-bend and coin-bend operations. These types of bend operations require a particular tool. The same tooling cannot be used to realise all these mentioned bendings. Air-bend type is the most preferable one, however, tolerance of angles, demanded inner radius may lead to bottom and coin bending. The formed inner radius during bending of the air is connected with the hole of the matrix (0.156 times the hole of the matrix) or 1.25 times the thickness of the materials.
In case of bottom bend, the inner radius nearly equals the stuff thickness; in case of coin, the inner radius equals the radius of punches. The piece angular tolerance depends on the equipment precision and accurate tools.
An operator ought to know all existing tools. Besides, he must actually test tool tolerance every time punches or dies are taken out of storage. The responsibilities of operators include making sure about the correspondence of tools with its manufactury specification. Otherwise, there will be a need for replacing or remachining them. Improper tools provide insufficitient quality of pieces.
The whole relevent data on part formation appear in the drawings. These involve piece dimension, bending angles, inner radius, sizes of blanks, suitable tolerances. Drawings have to be made upon the brake capacity, tools required for the task. In case of omitting any necessary data, operators are surly to face a trouble. An operator should paractise about the relation between a drawing and the tools or equipment.A skillful and experienced operator will surely ensure precision, efficiency as well as productivity. The management should in their turn guarantee all the required trainings to provide the operator with the necessary experience.