Facebook
Twitter
LinkedIn

Application of high-speed five-axis machining center in automobile mold manufacturing

Introduction: Nowadays, automobile molds have increasingly higher requirements for the surface quality and cutting speed of molds. The best cutting state can be achieved when using a five-axis CNC system to process planes with three-dimensional curves. Different geometric shapes can be processed by changing the setting angle of the tool axis at any position within the machine tool processing area.

Three-axis machining center for deep cavity mold processing

The design of automobile parts is mainly completed by CAD systems, reverse engineering and various tests. The processing procedures for the complex surface of the mold come from CAM software. However, how to ensure the accuracy of design and processing depends on CNC machining. Let’s discuss some five-axis processes in mold processing. The relationship between the application of CNC systems and the quality of molds.

Comparative application of three-axis machining and five-axis machining molds

Three-axis machining centers can only process deep-cavity molds by lengthening the tool shank and cutting tools (see Figure 1). However, when processing deeper and steeper cavities, five-axis machining centers can add additional components to the workpiece or spindle head. Rotation and swing create the best process conditions for processing, shorten the tool length appropriately, and avoid collisions between the tool and tool shank and the cavity wall, reduce tool jitter during processing and the risk of tool breakage, thereby improving the surface quality of the mold. , machining efficiency and tool life (see Figure 2).

When using a three-axis machining center to process the side wall of a mold, the depth of the side wall determines the length of the tool. The tool length must be greater than the depth of the side wall. When the tool length increases, the strength of the tool will be reduced. If the tool length exceeds 3 When the diameter is doubled, the tool will give way, making it difficult to ensure the quality of the workpiece (see Figure 3). When using a five-axis machining center to process the side wall of the workpiece, you can swing the workpiece or the spindle to make the tool perpendicular to the side wall of the workpiece, and then use a plane milling cutter to mill the side wall, which can ensure the quality of the workpiece and extend the tool life (see Figure 4).

When using a three-axis machining center to process a relatively flat curved surface, a ball cutter should be used for fine milling to obtain better surface quality, so the tool path should be increased. But as we all know, the linear speed of the tool center rotation of the ball-nose tool is close to zero, so it causes great damage to the tool during processing, shortens the tool life, and worsens the surface quality (see Figure 5). When using a five-axis machining center to process a relatively flat curved surface, in order to increase the relative linear speed between the ball-end cutter and the workpiece, the cutter is machined at a certain angle on the workpiece as shown in Figure 4, so that the distance between the ball-end cutter and the workpiece is increased. The relative linear speed increases, which can not only improve the life of the tool, but also improve the surface quality of the workpiece (see Figure 6).

In addition, when machining a normal hole on an inclined surface in a five-axis machining center, the machining action in a swing-head machine tool is to place the spindle in a direction perpendicular to the slope on the workpiece by swinging the head and then position it to the position of the hole. It is necessary to process the hole. At least two linear axis interpolation movements can be used to process oblique holes, which greatly reduces the accuracy of the holes. When using a swing-table five-axis machining center for bevel hole processing, the action is to place the slope on the workpiece in a direction perpendicular to the spindle through the swing table. During hole processing, only one linear axis movement of the spindle is required, which greatly improves the processing efficiency. Hole accuracy (see Figure 7).

Other advantages of five-axis machining systems

Nowadays, automobile molds have increasingly higher requirements for the surface quality and cutting speed of molds. The best cutting state can be achieved when using a five-axis CNC system to process planes with three-dimensional curves. Different geometric shapes can be processed by changing the setting angle of the tool axis at any position within the machine tool processing area. Irregular curved surfaces with the same shape are usually processed with three axes. The direction of the cutting tool remains unchanged during the movement along the entire cutting path. The cutting state of the tool tip cannot always be perfect in all parts of the entire curved surface.

For deep grooves or surfaces that frequently change curvature, a five-axis CNC system is required for processing. The direction of the tool or the position of the workbench can be changed. The cutting tool can always maintain the best cutting state while moving along the entire processing path. The tool direction can be optimized while the tool moves linearly, so that perfection is achieved in all parts of the entire curved surface. If you want to mill a straight line with no change in direction, just draw a straight line on the tool holder. If the direction changes at the same time, the tool tip draws a curve. If the tool tip can draw the required straight line when the direction changes, this curve must be compensated, which is a crucial point in five-axis machining. The tool rotates around the center of the axis without the control system taking the tool length into account. The tip of the knife will move out of its position and is not fixed. However, a five-axis control function has been added to the control system. The control system only changes the direction of the tool, and the tool tip position remains unchanged. Necessary compensation movements on the X, Y, and Z axes have been automatically calculated to ensure machining accuracy.

Request For Quote

small_c_popup.png

Let's have a chat

Leave your information, our sales will contact you as soon as possible!