Some common problems and solutions in the assembly, debugging and use of laser cutting gas circuit are as follows:
1. When the laser cutting machine is cutting stainless steel plates, the actual value of the oxygen pressure provided by the air supply system is 1.5mpa, which exceeds the normal use range (0-1.0mpa) of the conventional NITV electric proportional valve, which causes the proportional valve to fail.
2. In the process of assembling and using the electric proportional valve, the operation sequence of first turning on the air source and then opening the control terminal to control the proportional valve is not strictly followed. Instead, the control terminal inputs instructions to the ventilation source. Some proportional valves are opened, and the air is returned. If it does not arrive, it will cause the proportional valve to act without air source and produce abnormal noise. The service life of the on-off solenoid valve in the proportional valve will be reduced, and the solenoid valve will be burned in severe cases.
3. When the customer connects the proportional valve signal and the module signal line, the copper wire of the signal line is not well connected, resulting in connection resistance and attenuation of the proportional valve signal, which affects the normal operating pressure of the electrical proportional valve.
4. When customers assemble electric proportional valves and two-way valves, connect air pipes, joints, and copper pipes, improper operation produces particles such as copper scraps, aluminum scraps, iron scraps, and plastics. These particles enter the electric proportional valve and cause damage to the proportional valve and cause electrical damage. The proportional valve exhausts slowly or cannot be closed at all, causing the digital display to rise slowly after the proportional valve is closed, and there is air leakage in the cutting head. It is best to carry out the pipeline after all the joints and the like are processed and before assembling. Pre-blowing work. Another reason for this kind of phenomenon is that the sealing ring of the two-way valve is deformed, causing the normally open normally closed diaphragm to leak without completely closing.
5. When debugging, when the input pressure is relatively low, there is no gas coming out. This problem is generally that the starting pressure of the one-way valve is too high, and the relatively low air pressure can not open the one-way valve at all, so we have to choose a low starting pressure Check valve.
6. The filter selected for the gas source of oxygen and nitrogen should be at least a high-precision filter of 5μm or more. Otherwise, some small particles will gradually accumulate after a period of time, which will block the two-way valve or the electric proportional valve. The gas circuit cannot be used normally.
7. Separate the power line and the proportional valve control signal line as far as possible when wiring the cables on site to avoid signal interference, which may cause unstable pressure of the proportional valve.
Many of the above problems often cause equipment damage when they occur, resulting in unnecessary economic losses. After combining the after-sales experience of multiple customers, the professional technical team of Guangdong Nonnengtai Automation Technology Co., Ltd. added filters and pressure switches to the conventional laser cutting complete gas circuit. The improved pneumatic device is shown in the figure below:
1. The left side is the air inlet connection, and the right side is the laser cutting head connection
2. Group A in the picture is the low pressure type 0-1.0Mpa gas circuit connection diagram. The detailed accessories from left to right are: filter pressure regulator, pressure switch, high pressure two-way valve, electric proportional valve, high pressure check valve ( 2MPA), joints, copper pipes, joints. Group B is the high-pressure 0-3.0Mpa gas circuit connection diagram. The accessories from left to right are: high-pressure filter regulator (3mpa), high-pressure pressure switch (3mpa), high-pressure two-way valve, high-pressure electric proportional valve ( 3mpa), high pressure check valve, joint, copper pipe, joint.
Add a pressure switch to the air circuit device and set a pressure range value for the pressure switch, so that the air source through the electric proportional valve will only receive instructions to open the electric proportional valve when the pressure is within the allowable pressure range value. The switch will not give instructions to make the proportional valve work. This will not only extend the life of the electric proportional valve, but also avoid some accidents caused by our problems.