CNC shearing machine mold material technology and hydraulic system requirements

CNC shearing machine mold material technology and hydraulic system requirements

Since the 1970s, the concept of pre-hardening has been proposed internationally. However, due to the limitations of processing tools and abrasives rigidity, the hardness of pre-hardening does not reach the hardness of the use of the mold, so the development of pre-hardening technology invested half as much. With the improvement of the performance of machine tools and grinding tools, the development of mold material pre-hardening technology accelerated. By the 1980s, pre-hardening plate in the world’s developed countries in the proportion of plastic mold materials has reached 30.100% (now more than 60.100% ).

China’s pre-hardening technology in mold materials, late start, small scale, now shall not know the requirements of domestic mold making. The use of pre-hardening mold materials, can simplify the mold making process, shorten the mold making cycle, and grow the precision of mold making. It is foreseeable that with the advancement of processing technology, pre-hardened mold materials will be used for more mold types.

The operation of CNC shearing machine is the key process to ensure the performance of the seller, which directly affects the accuracy of the seller’s manufacturing, the strength of the mold, the service life of the mold and the manufacturing of the mold. since the 1980s, the international mold thermal processing technology has developed rapidly is the vacuum thermal processing technology, mold appearance strengthening technology and mold material pre-hardening technology.

Vacuum thermal processing technology of shearing machine

Vacuum thermal processing technology is a new thermal processing technology developed in recent years, its characteristics are much needed in the mold manufacturing, such as avoiding heating oxygen gasification decarburization, vacuum degassing or degassing, eliminating hydrogen embrittlement, thus increasing the material (parts) ductility, toughness and fatigue strength. Slow vacuum heating, small temperature difference between the inside and outside of the part and other factors lead to small deformation of the part during vacuum processing.

Vacuum oil quenching, vacuum air cooling quenching and vacuum tempering are mainly used in the shear processing. In order to maintain the superior characteristics of the workpiece (such as mold) vacuum heating, the choice and development of coolant and cooling process is very important, the quenching process of the mold is mainly used oil cooling and air cooling. For the mold office surface which is no longer machined after hot working, vacuum tempering should be used after quenching, especially for vacuum quenched parts (molds), which can increase mechanical properties related to appearance quality, such as fatigue performance, appearance brightness, corrosion resistance, etc.

The pressure retention of the pressurized circuit depends on three aspects, one is to compensate the leakage through the accumulator, the second is to fill the oil by the oil pump through the pressure reducing valve, and the third is to limit its maximum working pressure through the pressure reducing valve and solenoid relief valve.

In the shearing stroke, the synchronization of two cylinders is achieved by tandem cylinders. Since the size of the shear angle in the work is not very strict, the synchronization accuracy is not required to be high. The working area of the lower chamber of the cylinder piston is equal to the working area of the upper chamber of the cylinder, so as long as the sealing performance is good and no oil leakage, good synchronization can be maintained. Therefore, the sealing device of the two cylinders should be reliable, the valve set should be closed tightly, and the pipe joint should not leak oil. Provide an exhaust valve at the height making point for removing the air from the circuit.

After doing the above, the shear angle can still be kept within the allowable range after several working cycles, although there is no synchronous automatic letter filling device. When the shear angle exceeds the allowable range due to leakage and other factors, it can be adjusted by the valve set. When the shear angle becomes large, the middle and right two stop valves can be opened, the pressure oil in the accumulator into the upper chamber of the cylinder to form a differential circuit, so that the piston descends and the shear angle becomes smaller.

When the shear angle becomes small and needs to be increased, the left and right two stop valves can be opened, the pressure oil in the accumulator into the lower chamber of the cylinder, the upper chamber to the tank discharge oil, so the cylinder piston rises to increase the shear angle. The hydraulic system of this machine has no reversing valve, the oil return chamber of the cylinder is often under the pressure of the accumulator when working. When the tool holder drops, it can cause the back pressure to make the movement smooth, and when the tool holder stops, it can support the weight of the tool holder and other moving parts. When the tool holder descends, the return chamber is pressed to the accumulator through the controllable check valve to store the energy star.

When returning, the solenoid 2dt and 1dt are de-energized, the control valve opens, the high pressure oil in the accumulator pushes the tool holder back, and the oil in the upper chamber of the cylinder is discharged back to the tank through the one-way smooth valve and the overflow valve. When returning, the oil pump unloads, so the return power consumption is small. Due to the application of accumulator, the efficiency of the system is improved and less heat is generated.

Due to the application of accumulator, the efficiency of the system is improved and less heat is generated, so the normal working oil temperature can be maintained even under the condition of long-term continuous operation without setting a cooler. After the knife holder returns, it makes the 3DT power off, the press cylinder returns, the press head relaxes and the stripper cylinder returns to the original position. When shearing thin plate without using the pallets, you can make the stripper cylinder piston retracted after closing the shut-off valve in the valve, the stripper mechanism both keeps in the table and does not work.