Основные эксплуатационные параметры стригальной машины
1. Basic Performance Parameters of Shearing Machine
The main factors determining the performance of the shearing machine are: the shearing force of the стригальная машина, the pressing force, the shearing angle and the stroke amount of the upper blade.
2. Shear Force Determination
The total shear force of the inclined edge shearing machine is smaller than that of the flat blade shearing machine. It consists of three components: the basic shearing force; the bending resistance of the cut part of the sheet and the bending of the sheet in the shear zone. Resistance. The relationship between the total shear force and the shear angle is nearly inversely proportional, that is, decreases as the shear angle increases.
3. Determination of the Pressing Force
During the процесс стрижки, the upper blade exerts a forward horizontal thrust T on the sheet. In order to prevent the displacement of the sheet, the pressing force must be such that the horizontal frictional force generated on the top and bottom surfaces of the sheet is greater than T.
At the moment when the cutting starts, the cutting depth of the upper blade reaches the thickness of the sheared plate, and the friction generated by the top surface and the bottom surface of the sheet are:
F1=μ(Ph+Py)N
When the shearing continues beyond the above moment, the top surface friction of the sheet is:
F2=μPyN
The low friction of the sheet remains unchanged.
F1+F2≥T
T=0.3PhN
Therefore μ(Ph+2Py)≥0.3Ph
When μ=0.15
Py=1/2PhN
It should be said that the pressing force increases as the total shear force increases. However, the pressing force and the width of the sheared plate also have a certain relationship. When the shearing plate width is large, the pressing foot which is far away from the shearing region has little effect. To this end, the total pressing force is:
Py=1/2Ph b/2500 N
Where b—-is cut width (mm)
Bring the function value and get the Py value of 1.57*10.6N
4. Determination of the Shear Angle
It can be clearly seen from the formula of the shear force that as the shear angle increases, the shear force decreases, thereby reducing the weight of the machine. However, the most unfavorable consequence of the increased shear angle is the severe distortion of the narrow strip, followed by the increased stroke of the tool holder.
By comparing the main parameters of the domestic and foreign shearing machines, it is decided to set the shear angle to 3°.
