What Are The Elements Of Selecting A 5-Axis Machining Center?
We will take the industry-leading Makino 5-axis machining center as an example to introduce the main factors to be considered in selecting the 5-axis machining center.
01 Structure determines equipment performance
The 5-axis machining center has various structures. The structural design of the machine tool determines the performance of the equipment and the rigidity, machining accuracy, stability, operability and so on.
The following aspects should be considered:
1) The linear axis does not merge and stack when moving
2) The equipment with short cutting circuit has good rigidity
3) Is the tilt rotary shaft a DD motor
4) Is it 5-axis linkage
5) 5-axis proximity
Makino's D200Z/D800Z/A500Z series 5-axis machining center adopts the "Z" type high rigid worktable structure, as shown in the figure below. The worktable does not need support at both ends, large-diameter tilt bearing, and the workpiece center of gravity B is within a. Compared with the traditional single support structure, the bending amount D is very small and the force arm L is shorter.
This inclined axis structure can realize high-precision machining comparable to 3-axis machining center. Even if the heavy parts are loaded and rotated, the deflection of the worktable can be controlled to a minimum. At the same time, the high rigid bearing and direct drive motor can also realize high-precision and smooth rotation with less vibration. In addition, it has excellent spatial proximity.
The inclined axis structure has excellent spatial proximity
02 Tilt rotation axis accuracy
The machining accuracy of the machine tool is directly affected by the accuracy of the rotating shaft. Take Makino D800Z machine tool to understand the actual impact of the accuracy of the inclined rotating shaft on the machining accuracy.
1°= 60′1′= 60″1°=3600″
The minimum resolution of B/C axis of D800Z machine tool is 0.0001 degrees, that is, 0.36", and the positioning accuracy is ±3". Through the following calculation diagram, we can know the accuracy error.
03 Interference and collision avoidance
Interference and collision avoidance is a problem that can not be ignored in 5-axis machining. In addition to the software interference inspection at the computer end, Makino's 5-axis machining center is equipped with the function of online real-time simulation CSG of machine tool as standard, which can prevent interference even in manual mode.
Online real-time simulation CSG function can check possible tooling errors or tool length setting errors before machining, so as to minimize the emergency stop in operation. During operation, read the position information based on the data calibrated and adjusted in advance, as well as the coordinates and offset values in the CNC control device to predict the possibility of interference. Once the machine tool stops running, the status screen can be displayed immediately, and the predicted interference position and axis action direction can be confirmed.
04 Center of rotation correction
The change of rotation center caused by the change of environment and temperature will affect the machining accuracy of 5-axis. It should be able to be corrected automatically through the probe. The machining accuracy of 3-axis / indexing / 5-axis should be verified, and the tool receiving error < ±4μm。
05 Linkage accuracy
The linkage accuracy of 5-axis machining center is the embodiment of multi factor results. Taking Makino D200Z as an example, processing cases are listed to provide linkage accuracy reference.
Processing equipment: D200ZCAM: FFCAM workpiece material: NAK80(40HRC) workpiece size: 140x140x35mm cavity: angle clearing R0.22mm, depth 20mm, processing time: 1H35min/pocket tool: 7 pcs, 6 kinds
Linkage accuracy: position accuracy ±2μm. Shape accuracy ±3μm
06 Process support
The processing technology of the 5-axis machining center determines whether the performance of the equipment can be maximized. For example, special-shaped cutting tools can greatly improve the machining efficiency.
Processing case: efficiency increased by 6 times!
Material: YXR33(58HRC) shape and size: as shown in the figure below, the depth is 30mm, the draft angle is 2°, and the clearance angle is R3mm
