Do you know about the design and application of the receiving roller?
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The design of the receiving press roller is critical during the receipt of the gravure press. If the position of each part is not determined well, it will cause the cylinder stroke to be wrong, or the pressure roller can not take into account the large volume and small volume; if the weight calculation is incorrect, the cylinder pressure adjustment will be difficult, resulting in unevenness of the receiving material, and the core Wrinkles are particularly serious and the rate of scrap is increasing. The important indicator of user acceptance and receipt is the core wrinkle, so the position determination and weight calculation of each part of the receiving pressure roller must be carefully and carefully.
Common structure of the receiving pressure roller
The receiving pressure roller is mainly composed of a pressure roller, a support shaft, a fulcrum shaft, a swing arm, a cylinder, a weight, and the like. Common structures are divided into a double press roll form and a single press roll form.
1. Double pressure roller
The double pressure roller has a set of independent pressure roller structures for each of the A-axis and the B-axis of the receiving material, and the cylinder pressure is adjusted by the respective gas path components. The advantage of this form is that the cylinder pressure on each shaft does not interfere with each other, and the direction of the pressing of the current shaft is always the same. The disadvantage is that there are too many parts, and installation and debugging are cumbersome. This type of press roll is mainly used in the case where the center of rotation of the A-axis and the B-axis is supported, that is, it is often used in a tower turret that we often say. The schematic diagram of the double pressure roller is shown in Fig. 1. In the figure, the A-axis pressure roller is in a pressing state, and the B-axis pressure roller is in a retracted state.
2. Single pressure roller
The single pressure roller is a set of pressure roller structure for the receiving A-axis and the B-axis, and the cylinder pressure adjustment of the A-axis and the B-axis has only one set of pneumatic components. The advantage is that the parts are relatively small, the installation and debugging is relatively simple and convenient; the disadvantage is that the cylinder pressure adjustment must take into account both the A-axis and the B-axis, the calculation of the counterweight is very accurate, and the pressure directions of the A-axis and the B-axis are inconsistent. This form is mainly used in the case where the center of rotation of the A-axis and the B-axis is not supported, that is, it is often used in a disc turret that we often say. The schematic diagram of the single pressure roller is shown in Fig. 2. In the figure, the pressure roller is in three states of extension, neutral position and retraction.
Design of the receiving pressure roller
When designing the take-up roll, first determine the position of the part. Determine the length of the swing arm arm and the position of the fulcrum according to the length of the rotating arm of the shaft, the minimum roll diameter, the maximum roll diameter, the position of the guide roller, etc.; determine the stroke of the cylinder according to the distance moved by the fulcrum when the swing arm is turned from the minimum roll to the maximum roll; The diameter of the cylinder is determined according to the material and tension of the collected roll. After the size and fulcrum of these basic parts are determined, the position of the parts is basically determined.
The second is to calculate the weight, the pressure roller swing arm with the fulcrum as the boundary line. Under normal circumstances, the nip roller and the support shaft are at the long end of the swing arm, the weight is at the short end of the swing arm, and the fulcrum is the rotation center of the swing arm. According to the principle of static balance: A × L1 + B × L2 + C × L3 = D × L4 + E × L5. Where A is the mass of the nip roll, B is the mass of the struts, C is the mass of the long end of the swing arm, D is the mass of the counterweight, E is the mass of the short end of the swing arm, L1 is the distance from the center of gravity of the nip roll to the fulcrum, L2 is The distance from the center of gravity of the pivot to the fulcrum, L3 is the distance from the center of gravity of the long end of the swing arm to the fulcrum, L4 is the distance from the center of gravity of the counterweight to the fulcrum, and L5 is the distance from the center of gravity of the short end of the swing arm to the fulcrum. The mass can be calculated according to the material and shape of the part (volume x density); the distance can be determined according to the spatial position.
The frame of the receiving press roller is thus completed. Of course, there is always a certain gap between theory and practice, and processing errors and assembly errors are inevitable. Therefore, the mounting position of the counterweight must have a front and rear adjustable distance.