When the base plate is used on the machine tool, it is easier to set up and install fixtures by setting up threaded holes, reamed holes and grooves, etc. It is generally made according to the shape of the machining center table, and its functions include adjusting the height of the workpieces, protecting the machine tool table, and adjusting the orientation of the workpieces to carry out simultaneous machining of multiple surfaces as needed.
First, the type of base plate, base vertical machining centers mainly use the base plate. Horizontal machining centers in addition to the use of the base plate has a single-sided base, double-sided base and four-sided base.
Horizontal machining centers also use six-face and eight-face bases to correspond to various workpiece sizes. In Fig. 2, the darker orange color of the workpiece indicates the surface that can be machined.
Second, the type of base plate, base mounting surface of the base plate, base fixture mounting surface of the T-slot form, bolt hole form, the form of reference holes, and so on. In addition, in order to make the machining center accuracy and fixture mounting surface accuracy as perfect as possible, there are also forms of self-processing in the actual machining use.
Since each machine tool has its own characteristics such as the inclination of the floor of the factory where the machine tool is located, or the inclination of the spindle after years of use, it is possible to process the remnants of the fixture mounting surface to fit the individuality of the machine tool and to make the fixture mounting surface more accurate. There is also a form of disassembly and assembly that can be carried out outside the machine tool for workpieces and workpieces: quick change of workpieces.
Third, to determine the size and positioning method to choose the base plate, base, the first need to confirm the size and positioning method in advance. Horizontal machining centers for the basic size of 400X400, 500X500, 630X630, 800X800, depending on the machine tool manufacturers, there are 300X300, 1000X1000 and other sizes, 550X550 and other special sizes are also produced by machine tool manufacturers. The size of vertical machining center is different for each machine tool manufacturer, there is no special rule to specify the size. Each machine tool manufacturer has its own table dimensions, which can be found in the machine's instruction manual.
Horizontal machining center base plate, base positioning is generally used in the X, Y direction mounted on the table against the block, the base plate, the base by fitting the table against the block to complete the positioning. The position of the table resting block is generally set at 0° and 270° of the machine table, and the position of the table resting block varies depending on the machine tool manufacturer. Vertical machining centers generally have a keyway in the center of the table. The keyway is used to position the base plate and base in the X direction, and then the T-slot is used to position the base plate and base in the Y direction. However, not all T-slots can be accurately positioned, depending on the machine tool manufacturer, the machine has a positioning function of the T-slots generally only 1 or 2.
Fourth, confirm the maximum load capacity of the machine tool first confirm the maximum load capacity of the machine tool, and then confirm the total weight of the workpiece, fixture, base plate, base, the total weight should never exceed the maximum load capacity of the machine tool. Some designers also calculate the weight of the workpiece and base plate, base, forget to calculate the weight of the fixture, which can not be ignored.
If the total weight exceeds the maximum load capacity of the machine tool, you can choose to reduce the thickness of the base plate, reduce the thickness of the base mounting surface or the base into a hollow type and other methods, used to reduce the overall weight.
Fifth, confirm the height of the base and the maximum rotary diameter of the choice of the base plate, the maximum height of the base machine and the maximum rotary diameter must be confirmed in advance. Especially horizontal machining centers, the maximum rotary diameter is a matter that must be confirmed. Generally, the maximum rotary diameter is Φ630 for a base plate size of 400x400, and Φ800 for a base plate size of 500x500. The above two sizes are common, and there is no specific rule that requires the use of a base plate of these sizes. When the fixture is used to clamp the workpiece from top to bottom, the top of the fixture (the top of the bolt in the figure below) must be within the maximum swivel diameter.
Sixth, the machining range, travel confirmation in advance to confirm that the machine can be machined range (spindle range of movement) covers all the parts of the workpiece to be processed. In particular, the use of milling cutters for machining the surface of the time, the withdrawal of the tool, the spindle stroke whether the tool can be completely out of the scope of the workpiece must be considered in advance of the time of design, if you do not take into account the withdrawal of the knife, to ensure that the surface of the accuracy is more difficult. When the milling cutter withdraws from the workpiece, a minimum distance of 10mm or more needs to be ensured with the workpiece, that is, the cutter needs to be allowed to completely leave the workpiece range.