1. The role of the knife cylinder
The punching cylinder is mainly used for spindle punching in the automatic or semi-automatic tool exchange mechanism of machining center machine tools and CNC milling machines. It can also be used as a clamping device for fixtures and other mechanisms. 30# spindle generally uses 2.0T tooling cylinder. The 40# spindle generally selects a 3.5T punching cylinder. 50# spindle generally selects 6T punching cylinder.
Second, the working principle of the knife cylinder
The spindle of the CNC machining center is generally equipped with a knife cylinder to complete the installation and replacement of the tool holder. It is a power-increasing gas-liquid conversion device. The compressed air acts on the knife cylinder piston to generate thrust. The cutter head is clamped by pulling the cylinder. When the knife is set, the cutter head is loosened and cleaned by "blowing". It is convenient to change the tool and realize the action of the mechanical device.
Three, the common failure of the knife cylinder in long-term use
1. The solenoid valve of the knife cylinder is leaking
(1) The muffler is leaking. It is because the sealing ring in the valve body is worn or there is a foreign body in the valve body, which causes the piston in the valve to return to position. Replace the sealing ring to clear the inside of the body.
(2) Air leakage at the coil, damage to the gasket in the valve body or loosening of the valve body screws, check the valve body fixing screws and replace the gasket
2. "External leakage" failure occurred at the piston rod of the knife cylinder
(1) Check whether the guide sleeve, piston rod seal ring is worn, whether the piston rod is eccentrically worn, if the above situation occurs, replace the piston rod and seal ring, improve the lubrication effect, and use guide rails.
(2) Check whether the piston rod is scarred or corroded. If there is scarred or corroded, replace the piston rod.
(3) Check whether there are impurities between the piston rod and the guide sleeve. If there are impurities, remove the impurities, and then install the dust ring.
3. When the CNC machining center punches the cylinder block and the end cover of the "external leakage" failure
(1) Whether the sealing ring is damaged, if it is damaged, replace the sealing ring.
(2) Check whether the fixing screws are loose. If they are loose, tighten the fixing screws.
4. When the “internal leakage (that is, blow-by on both sides of the piston)” failure occurs in the punching cylinder of the CNC machining center
(1) Check whether the piston sealing ring is damaged, and replace it if it is damaged.
(2) Check whether the piston mating surface is defective. If there is any defect, replace the piston.
(3) Check whether there is any impurities on the sealing surface, and remove any impurities.
(4) Check whether the piston is stuck, if it is stuck, reinstall the piston. Eliminate the unbalanced load of the piston rod.
5. When a ‘stop’ failure occurs during the operation of the punching cylinder of the CNC machining center
(1) Check whether the load is concentric with the axis of the punching cylinder. If it is not concentric, use a floating joint to connect the load.
(2) Check whether solid contaminants are mixed in the knife cylinder. If there are contaminants, clean up, and at the same time improve the quality of air produced by the air source.
(3) Check whether the sealing ring in the knife cylinder is damaged. If it is damaged, replace it.
(4) Check the guidance of the load. If the guidance is poor, readjust the guidance device of the load.
