How to reduce the thermal deformation of the portal milling machine?

Cause: Under the influence of internal and external heat sources, various parts of the gantry milling machine will undergo thermal deformation of different degrees, causing the relative motion relationship between the workpiece and the tool to be broken. For the portal milling machine, because all the machining processes are computational instructions. The effect of thermal deformation is even more severe.

In order to reduce thermal deformation, the following measures are usually used in the structure of a portal 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. However, it is usually very difficult or even impossible to completely eliminate the heat sources inside and outside the portal milling machine. Therefore, the temperature rise must be controlled through good heat dissipation and cooling to reduce the impact of heat sources. One of the more effective methods is to force cooling in the heating part of the gantry milling machine, or through the heating method in the low temperature part of the gantry milling machine, so that the temperature of each point of the gantry milling machine tends to be consistent, which can reduce the warpage caused by the temperature difference.

2: To reduce the main heat source that generates heat distortion during the heat generation inside the gantry milling machine, 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 portal milling machine, the thermal deformation of the spindle should be as far as possible in the vertical direction of the tool cutting. This can minimize the effect of hot deformation of the spindle on the machining diameter. The structure should also reduce the distance between the center of the spindle and the main axle as much as possible to reduce the total amount of thermal deformation. Simultaneously, the front and rear temperature rise of the spindle box should be consistent to avoid tilting after the spindle is deformed.

4: Improvement of Gantry Milling Machine Under the same heating conditions, the portal milling machine mechanism also has a great influence on thermal deformation. For example, the single column mechanism used in the gantry milling machine may be replaced by a double column mechanism. Due to the left-right symmetry, the main axis of the double column mechanism is heated except for vertical translation. The deformation in other directions is very small, and the axis movement in the vertical direction can be easily compensated by a coordinate correction amount.