CNC milling machine is a kind of automatic processing equipment developed on the basis of general milling machine. Their processing technology is basically the same, and their structures are somewhat similar. CNC milling machines are divided into two categories: without tool magazine and with tool magazine.
CNC milling machine is a kind of automatic processing equipment developed on the basis of general milling machine. Their processing technology is basically the same, and their structures are somewhat similar. CNC milling machines are divided into two categories: without tool magazine and with tool magazine. CNC milling machine with tool library is also called machining center.
1. Classification according to tool change form
(1) The tool changing device of the machining center of the machining center with the tool magazine manipulator is composed of the tool magazine and the manipulator level, and the tool changing action is completed by the manipulator.
(2) Machining center of manipulator The tool change process of this machining center is completed by the tool magazine and the spindle box.
(3) Turret magazine type machining centers are generally used in small machining centers, mainly for machining holes.
2. Classification according to machine tool shape
(1) Horizontal machining center refers to the machining center whose spindle axis is horizontal. Horizontal machining centers generally have 3-5 motion coordinates. It is common to have three linear motion coordinates (along the X, Y, Z axis direction) plus a rotation coordinate (workbench), which enables the workpiece to be clamped at one time to complete the processing of the other four surfaces except the mounting surface and top surface. The horizontal machining center has a wider application range than the vertical machining center, and is suitable for machining complicated box parts, pump bodies, valve bodies and other parts. However, the horizontal machining center covers a large area and weighs a lot; The structure is complex and the price is high.
(2) Vertical machining center refers to the machining center whose spindle axis is vertical. Vertical machining centers generally have three linear motion coordinates, and the workbench has indexing and rotation functions. A horizontal axis CNC turntable can be installed on the workbench to process spiral parts. Vertical machining centers are mostly used to process single cylinder boxes, case covers, plate parts and plane cams. The vertical machining center has the advantages of simple structure, small floor area and low price.
(3) The gantry machining center, similar to the gantry milling machine, is suitable for processing large or complex workpieces.
(4) Universal machining center Universal machining center is also called five side machining center Small workpiece clamping can complete the processing of all surfaces except the mounting surface; It has the function of vertical and horizontal machining center. There are two common types of Wanjian lying machine centers: one is that the spindle can rotate 900, which can be like a vertical machining center or a horizontal machining center; The other is that the spindle does not change direction, while the worktable rotates 900 with the workpiece to complete the processing of five faces of the workpiece. The installation of workpieces in the universal machining center avoids the installation error caused by secondary clamping, so the efficiency and precision are high, but the structure is complex and the cost is high.
Machining centers are usually divided into vertical machining centers and horizontal machining centers according to the state of the spindle in space. Vertical machining centers are those whose spindle is vertical in space, and horizontal machining centers are those whose spindle is horizontal in space. Spindles that can be converted vertically and horizontally are called vertical and horizontal machining centers or five sided machining centers, also known as composite machining centers. Divided by the number of columns of the machining center; There are single column type and double column type (gantry type).
According to the number of motion coordinates of the machining center and the number of simultaneously controlled coordinates, there are three axis two linkage, three axis three linkage, four axis three linkage, five axis four linkage, six axis five linkage, etc. Three axis and four axis refer to the number of motion coordinates of the machining center. Linkage refers to the number of motion coordinates that the control system can simultaneously control, so as to realize the position and speed control of the tool relative to the workpiece.
According to the number and function of workbenches, there are single worktable machining centers, double worktable machining centers, and multi worktable machining centers.
According to the machining accuracy, there are ordinary machining centers and high-precision machining centers. Common machining center, resolution 1 μ m. Maximum feed speed: 15 ～ 25m/min, positioning accuracy: lO μ M or so. High precision machining center with resolution of 0.1 μ m. The maximum feed speed is 15~100m/min, and the positioning accuracy is 2 μ M or so. Between 2 and lO μ M, with ± 5 μ M, which can be called precision level.