Manhart How does the punching and shearing machine generate shear force on straight steel?

The generation of shear force on straight steel by the punching and shearing machine can be described in points as follows:
1. **Principle Overview**:
– Shear force is the relative displacement deformation phenomenon of the cross section of the material along the direction of the external force under the action of a pair of lateral external forces that are very close, of the same magnitude and in opposite directions.
– In the punching and shearing machine, this lateral external force is generated by the upper and lower dies or shear blades of the punching and shearing machine during relative movement.
2. **Generation process**:
– **Drive part**: Through the hydraulic or mechanical transmission system, the punching and shearing machine is powered to drive the upper and lower dies or shear blades to move relative to each other.
– **Working part**:
– The upper die (or shear blade) is fixed on the upper die plate, and the lower die (or shear blade) is installed on the lower die plate. The distance between the two can be controlled by the adjustment mechanism of the punching and shearing machine.
– When the straight steel is placed between the upper and lower dies, by controlling the relative movement of the upper and lower die plates, the upper die (or shear blade) moves downward to form a certain shear angle with the lower die (or shear blade).
– As the upper die (or shear blade) continues to move downward, due to the shear angle between the two, the straight steel is subjected to equal and opposite lateral external forces at the shear surface, resulting in shear deformation.
3. **Influencing factors**:
– **Metal properties**: The physical properties of the straight steel, such as strength and plasticity, will affect the magnitude of the shear force.
– **Shear angle**: The shear angle between the upper and lower dies or shear blades is also an important factor affecting the magnitude of the shear force.
– **Deformation speed**: The deformation speed during the shearing process will also affect the magnitude of the shear force, especially during the hot shearing process.
4. **Conclusion**:
– The shear force of the punching and shearing machine on the straight steel is generated by the working parts, the upper and lower dies or shear blades, applying equal and opposite lateral external forces to the straight steel in relative motion. This shear force causes the straight steel to undergo relative displacement deformation at the shear surface, thereby achieving the purpose of shearing. At the same time, the magnitude of the shear force is affected by many factors, such as metal properties, shear angle and deformation speed.