Reason: Under the influence of internal and external heat sources, various parts of the gantry milling machine will undergo different degrees of thermal deformation, which will cause the relative motion relationship between the workpiece and the tool to be broken. For the gantry milling machine, because the entire machining process is a calculated instruction Controlled, the effect of thermal deformation is even more serious.
In order to reduce thermal deformation, the following measures are usually adopted in the structure of the gantry milling machine.
- 1: Controlling temperature rise After taking a series of measures to reduce the heat source, the situation of thermal deformation will be improved. But it is usually very difficult or even impossible to completely eliminate the internal and external heat sources of the gantry milling machine. Therefore, temperature rise must be controlled by good heat dissipation and cooling to reduce the influence of heat sources. One of the more effective methods is to force the cooling in the hot part of the gantry milling machine, or you can use the heating method at the low temperature part of the gantry milling machine to make the temperature of each point of the gantry milling machine tend to be consistent, which can reduce the warpage deformation caused by the temperature difference.
- 2: To reduce the main heat source of heat distortion generated when the gantry milling machine generates heat, the heat source should be separated from the host as much as possible.
- 3: Improvement of the spindle box For the spindle box of the gantry milling machine, the thermal deformation of the spindle should be as much as possible in the vertical direction of the cutting tool. This can minimize the effect of thermal deformation of the spindle on the machining diameter. In terms of structure, the distance between the center of the main shaft and the ground of the main axis should be reduced as much as possible to reduce the total amount of thermal deformation. At the same time, the temperature rise of the front and back of the main shaft box should be consistent to avoid tilting after the main shaft is deformed.
- 4: Improve the gantry milling machine mechanism Under the same heating conditions, the gantry milling machine mechanism also has a great influence on thermal deformation. For example, the single column mechanism used in the gantry milling machine in the past may be replaced by the double column mechanism. Due to the left-right symmetry, the main axis of the double-column mechanism is heated in addition to the vertical direction.