Views: 5 Author: DURMAPRESS Publish Time: 2021-08-12 Origin: DURMAPRESS
Cnc shearing machine is a machine that uses one blade to cut the plate with a reciprocating linear motion relative to another blade. By means of a moving upper blade and a fixed lower blade, a reasonable blade clearance is used to apply shear force to metal plates of various thickeners, so that the plates are broken and separated according to the required size. hydraulic shearing machine belongs to a kind of forging machinery, the main role is the metal processing industry. Products are widely used in aviation, light industry, metallurgy, chemical industry, construction, shipbuilding, automobile, electric power, electrical appliances, decoration and other industries to provide required special machinery and complete sets of equipment.
During the shearing machines process, the upper blade of the plate shearer will produce a horizontal thrust T, which is generated by the horizontal component of the thrust of the shear cylinder, the bending of the steel plate and the horizontal component of the shear process. The generating mechanism is complex, and the empirical estimate is roughly T= 0.3p. The force on the frame and the force on the tool rest are acting and reacting forces. The force model can be simplified by the geometric structure of the tool rest.
The stress point in the structure of the tool rest is on the blade. Due to the particularity of the material used in the tool rest, the stress at the blade is not considered here. Only the other parts composed of ordinary carbon steel are considered, and the stress concentration is located at the cylinder installation of the wing plate, the missing hole of the roof and the connection between the roof and the upper side plate. The vertical plate and the bottom plate are stressed, but the steel plate used in its design is thicker than the rest of the steel plate, and the stress direction is one, but not much.
Pressing device is a very important auxiliary device in the shearing process. There will be different devices in different types of plate shears, including gradual pressure and constant pressure. The shear machine analyzed in this paper is a pressing device using a hydraulic cylinder with constant pressure. When calculating the demand pressing force, ensure that the rated thrust of the cylinder is not less than the pressing force. When considering the pressing force, it must first at least ensure that the pressing force can prevent the warping of the plate during the shearing process, and the pressing force is also related to the thickness and width of the plate and the type of plate cutter.
The performance index of plate shearing machine has two points: first, the stress of the other parts of the plate shearing machine except the blade shall not exceed the allowable stress of ordinary carbon steel, that is, shall not exceed 235MPa; Two is the horizontal deformation of the pressing material frame shall not exceed 1/20 of the thickness of the steel plate, that is, shall not exceed 0.6mm. Therefore, the structural analysis of plate shearing machine focus is to analyze the stress concentration of the plate shearing machine, the strain part needs to be clearly known in the finite element calculation of the deformation range.