Milling processing is a typical processing of cutting. This is a processing method that cuts the flat -angle of the work using a milling tool such as the front milling (face mill). It is suitable for cutting square parts called square items, and is used with a tool called face mill or end mill for fixed processing work, and cuts the plane, side and groove of processing work. Face mills are suitable for efficiently cutting a wide area, and the end mills have a small area, but can be processed in various ways. In this article, we will explain the issues generated in the milling process, especially in the front milling process, and the points that you want to keep for efficient processing.
There are various types of milling, such as plane, sides, steps, and grooves. The following tasks common to these milling processes include: Processing due to scaring occurs
The milling that is greatly cut into the work is a processing method with a large load on tools. As a result, the life of the chips tends to be shorter than other tools.
Plan surface milling is a processing method that efficiently cuts the surface of the metal. It is common for processing to use the front milling (chip replacement type) front milling. Because the cut surface is large than the milling processing, there are the following issues. that has a large cutting resistance and is likely to be chattering
.Depending on the size of the cutting surface and the tool diameter, the number of simultaneous cuttings during processing (the number of blades hitting the work at the same time) fluctuates. As the number of blades increases, the interval between the cutting blades becomes narrower, so that the drainage is poorly exhausted, and the simultaneous cutting blade increases, so the cutting resistance increases. In addition to the rise in simple cutting resistance, the cut powder that could not be discharged is bitten during cutting, which makes it easier to vibrate and generate vibration.
There are the following measures to suppress the waving of milling and improve chip life.
As a main measure for controlling the occurrence, it is effective to review the tools to be selected and adjust the cutting conditions. In a word, there is a variation in the countermeasures as follows, even though it is a measure to suppress it.
By shortening the protruding of the milling tools, the occurrence of chattering due to the swing and flashing of the tools is suppressed. Selecting a lightweight tool such as aluminum material is also a point of chattering suppression. Depending on the work size and processing path, you need to be careful because the tool holder and the work will interfere.
Milling tools where chips are evenly arranged can resonate with cutting resistance and can lead to scarce. In that case, the vibration can be distributed by using a milling tool with an uneven (inequality pitch) with a chip arrangement (inequality pitch). It is valid if you cannot shorten the protruding of the milling tool.
Adjusting the cutting conditions such as "cut angle" and "cut amount" and reducing the cutting resistance to reduce the generation of chattering. It is common to reduce both the cut angle and the amount of cutting, but the thinnight work requires adjustment according to the conditions, such as increasing the cut angle.
Correct cutter paths and cheating generations during processing are important factors that guarantee stable blades and long tool life in milling.
By cutting into the work while drawing a curve (roll -in approach), the load at the start of cutting minimizes the load and prevents chipping. Since the cut powder at the time of cut is thinned, it is also effective in suppressing chattering.
During processing, adjust the milling tool so that it always contacts the work and reduce the number of cut times. Reducing the load on the tool leads to improving the life of the chip.
For flat milling processing, there are the following measures.
The main cutting resistance is concentrated in the diameter direction. This causes a cutter deflection with a long protruding amount. In other words, reducing the cutting resistance leads to a chattering control.
By shortening the protruding of the front milling, it suppresses the occurrence of chattering due to the swing and flashing of the tools. It is also effective to reduce the tool diameter, but it is necessary to consider comprehensive consideration to affect the processing efficiency.
By constantly hitting a certain number of blades on the cutting surface, the occurrence of chattering is suppressed. It is also effective for chattering to shift the center of the tool and the center of the work and increase the number of simultaneous cutting blades. In addition to changing the number of blades, the angle of the cut -blade is also reduced.
There is a discharge of cutting powder. If the drainage is poor, the cut blade of the end mill will be chopped to make the finish surface worse. If you proceed further, it will cause a clogged clogging, causing a cut -off deficiency and a break in the end mill itself.
The more blades of the milling tools, the more stable the cutting resistance and the higher the processing accuracy. However, as the number of blades increases, care must be taken because the "chip pocket" becomes smaller and the drainage of the powder is poor. Cutting must be drained reliably because it causes chattering and work damage.
What is a chip pocket? : The depression between the chips. It is important to take a large chip pocket for smoothly draining the cut powder What is the milling tool using a milling tool? Summary In this article, we explain the challenges generated by milling and the points you want to keep. At first glance, it looks simple, but even the NC -controlled machining center requires advanced knowledge and experience. In order to increase the processing efficiency while suppressing chattering, it is important to consider comprehensive consideration based on requirement accuracy and productivity.
