Long-term machining: In the cutting of difficult-to-machine materials, the service life of a turning tool is very short, and the milling cutter can be used for a long time because it distributes the cutting load by multi-edge cutting. Since the milling cutter has a long service life, the trouble of multiple tool changes in the middle of cutting can be eliminated.
Eccentric machining or profile machining: The radial (X-axis) movement of the milling cutter can be combined with the rotary motion of the workpiece to machine the contours of complex parts. Sandvik uses this technology to rough-process a trilobal conical "capto" tool chuck. In the same principle, in one setup, the part rotates and the cutter reciprocates, and the eccentric asymmetrical parts can also be machined in one setup. The eccentric shaft on the crankshaft of a car engine is also a good example. However, a lot of research work is needed in terms of processing accuracy.
Turning and milling technology
Turning and milling, there is no special requirement for the machine tool, but at least one Y-axis motion is required.
The rotation of the workpiece provides the C-axis motion for the milling cutter to deliver the required feed rate (power). However, the cutting speed that the workpiece needs to achieve is measured in ipm instead of the lathe (which means that the workpiece is much lower in turning and milling than in turning). However, the Y-axis motion is needed because the milling cutter has to do a lot of eccentric machining. Moreover, when the tool is eccentrically machined, it cannot be machined to the required size of the part. Because the tool center is at the center, the tool center and the rotation center of the part just intersect, and the tool can only use its end face for cutting (ie, it cannot be cut), instead of using Its cutting edge is cut. To ensure proper cutting of the cutting edge, the tool centerline will have to offset the part rotation centerline to 1/4 of the tool diameter. There are three types of tools that can be used effectively in turning and milling, the main reason being the use of wiper blades or cutting edges. For end mills in turning and milling, large flat or heavy-duty intermittent cutting is possible. Insert end mills are used for step milling. Use integral end mills to machine outer circle parts and finish deeper narrow slots. The wiper blade structure of the above tool achieves high-efficiency and high-precision machining by cutting two of the four cutting edges of the tool to the depth of the part.
However, with this method, problems occur when the tool is machined close to one step and one groove. At this time, after the eccentric tool is processed, many rounded corners will be left on the surface of the part.
In order to machine these fillets, the tool must be machined a second time. Tool skew is no longer required at this time, and the tool is moved along the Y axis to the center of the part for machining. This time, the so-called secondary processing, can not cut into the metal material (sometimes need to leave some margin processing), unless the step must be cleared, which is not allowed in actual use.
In the turning and milling process, the fact that it is unsatisfactory despite its dissatisfaction is the shape error of the machined part. When the milling cutter performs circumferential milling around the part, it will inevitably form some regularly spaced scalloped marks on the surface of the part. This error cannot be completely eliminated, but it can be effectively controlled using a wiper blade. A wiper blade is followed by the other blades, causing the cutting edge to protrude slightly in the width direction, so that the cutting edge of the blade extends just into the surface of the machined part, a new cutting surface is machined, and the fan-shaped traces are slightly flattened. .
Mr. Grimes said his company's tools for turning and milling are concentrated on the wiper blade structure. This type of wiper blade tool has been used to better control scalloped marks. Because the law reveals that a special wiper blade allows the user to control the shape error caused by the similar part to the extent that the general product quality can be allowed under the selection of reasonable turning and milling parameters.
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Set screw is also called head screw and positioning screw. The utility model is a screw specially used for fixing the relative position of machine parts. Type: square flange end set Bolt, GB / t821-1988 square chamfered end set screw, GB / t85-1988 square long cylindrical end set screw, inner square head set screw, etc.
Related categories
Hexagon socket set screw, hexagon flat set screw, hexagon cylindrical set screw.
The selection of common set Screws is generally used to fix the relative position of two parts with little force. The axial and circumferential positioning of common sleeve like parts on the shaft. There are many kinds of set screws. The common ones are as follows: according to the end part, there are conical end, flat end, concave end, oblong cylinder head, etc;
According to the head part: slotted, hexagon socket, square head, etc. Tapered end screws and concave end screws with sharp ends can be used to directly top the parts, and the concave end is more reliable and can bear greater force; Taper end screws without sharp points must be drilled in the parts. The flat end is used to top the tight plane, which does not damage the parts, but bears limited load.
Slotted screws have small tightening force and are often easy to screw off. Generally, they prefer hexagon socket head; The tightening force of square head is the largest, but it can not be embedded in parts, and its use is limited. In order to prevent loosening and withdrawal of threaded parts, a set screw can be drilled at the cross seam. The long cylindrical head screw at the top end is used in the keyway of the shaft to lock and prevent circumferential rotation. It can also be used in general unimportant occasions when the key slides in the keyway of the shaft.
Set Screws,Allen Nose Set Screw,Slotted Head Set Screw,Hexagon Socket Grub Screw
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