A brief analysis of the variable speed state of CNC lathe

In CNC lathe, the hydraulic power station can be placed behind the machine tool as a module. In the mass processing of tailstock, the hydraulic tailstock system can be added to make it become another operable module and share the same hydraulic power system.

During processing, when the program runs to the state where speed change is required, the NC system sends a stop signal first, and then the program sends a control signal to start the hydraulic pump to supply oil. At the same time, the solenoid valve of the hydraulic system pulls in according to the control signal to supply oil to the speed change cylinder, so that the piston rod extends or retracts, and pushes the shift fork to change the gear. When the gear moves in place, When the cam touches the microswitch and feeds back the signal to the NC system, the speed change ends and the program continues to run downward to execute the workpiece.

The spindle speed change module is installed on the spindle box, which is composed of support, oil cylinder, oil pipe, microswitch, etc. The length and width of the support is the same as that of the top of the spindle box. The whole spindle speed change module is installed on the four screw holes originally used to install the cover plate on the spindle box, and the positioning pin holes are added for the positioning of the module. The middle part of the support is supported by a diaphragm, and the speed change oil cylinder is fixed on the diaphragm and located directly above the gear shaft to control the sliding, which is coaxial with the guide shaft; The piston rod of the oil cylinder is located in the guide shaft and is connected with the shift fork through the pin shaft; The shift fork is sleeved on the guide shaft and can move back and forth along the guide shaft driven by the piston rod; The guide shaft is hollow and provided with a guide groove so that the piston rod is connected with the shift fork. The guide shaft is fixed on the support by a pin shaft; The two gear shift forks are of downward vertical structure and are respectively clamped in the speed change groove of the corresponding sliding gear.

When the oil cylinder supplies oil during speed change, the piston rod drives the sliding shift fork to move the sliding gear through the pin shaft to make the gear engage with speed change. After the gear is in place, the boss on the shift fork touches the microswitch on the cover plate and sends the gear in place signal, then the speed change is over.