making grooves and grooves is an ancient form of materials processing. In those days, they used chisels and cutters. Removal of chips from the workpiece is done by impact with a hammer on the tool. In fact, the required deepening just vydalblivanii. However, due to the low impact force and the geometry of the incisors, this method did not allow to meet the required dimensions and smooth edges of the slots, especially closed.
So over time, machines running on steam power, electricity. Their use has allowed to eliminate the above disadvantages.
At present, such processing is carried out slotting machines. Their primary equipment are pattavina mills.
What pattavina mill?
This cutter is the tool intended for machining slots and grooves. It is a body of rotation. Consists of items such as cutter, notch and shank.
Cutting edges can be sharpened both under positive, often acute, and at a negative angle. They have an inclination to the axis of the cutter. This excludes, first, changing the groove size after regrinding, and secondly, the processing is virtually no chipping of edges treated of edges. This is true when the swotting.
Groove for discharging chips can be made straight or curved. Often one face of the notch is straight, and the other sharpened at an angle to the axis for improved ejection of chips.
Shank has a cylindrical shape. Typically, the shank diameter is smaller than the same size cutting part. As a result, these tools are characterized by the absence of radial runout and the need for preliminary alignment.
the Principle of processing with this tool is that mill hollow is a groove in the workpiece. And it can move both down and up to the starting position. This is governed by the depth of the groove. Its movement can be carried out both in manual and automatic mode depending on the machine model. At the same time, the removal of a layer of the workpiece is performed by the cutters of the cutter as it rotates.
unlike ordinary cutters, pattavina cut the material in the course of working. Turns out this intermittent mode of operation.
these cutters with a diameter of 8 mm made from high speed steel, and their cutters from carbide materials. Structurally, the hull is done in one piece, and a cutter mounted on the cutter. With a diameter of 2 to 6 mm are made entirely from solid monolithic alloy. All this increases the strength characteristics and service life of the tool as a whole.
Used for machining of non-ferrous metals, wood, chipboard (DSP).
Where used pattavina mill?
These cutters are used for such works, such as the treatment of open and closed grooves, including keyways, and grooves. Their scales are small and do not go beyond small-scale industries.
Typically used in the following spheres of activity:
— metal in mechanical engineering;
— wood processing and furniture manufacturing;
— manufacture of doors and Windows.
Some mills are also used for engraving letters on the surfaces. The most popular they have sought in making grooves and spikes in window frames and doors. All this is done pastoviai cutters. What are the different types of cutters?
Varieties pattavina mills
Like all cutters, these tools vary in form of working part, in particular, on the geometry of the cutters and grooving. According to the signs can be divided into milling for deep holes and on the so-called V-shaped.
Pattavina cutters for deep hole
Used for processing soft and hard wood in joinery. In particular, the fabrication of the slot and tongue and groove joints, milling of recesses for installing hinges, door and furniture locks.
Contains items such as cutting edges, the groove and the shank. The latter is usually done cylindrical. The most common milling cutters with shank at diameter 6 and 8 mm.
a Characteristic feature of this type of tool is that the axial rake angle of the cutting edge is made negative and can take values up to 15°. This allows, first, to obtain a clean surface, and secondly, to avoid burying the tool when the swotting of deep holes, and, thirdly, to reduce the tool wear.
while the cutting edge also has an angle of inclination to the plane of the work surface. This design helps to eliminate problems with the entrance of the cutter into the workpiece. This is especially true when you consider that swotting occurs in the vertical direction. The angle is usually small, and usually taken in the range up to 20°.
the Grooves along the length of the instrument is made direct. In cross section it has the shape of an arc that improves the speed of chip removal. However, the processing requires a supply of compressed air to remove it.
the cutter Body is made from tool steel alloy. The cutters themselves are made of hard metal, which is soldered into the mill.
V-shaped pattavina mills
They are a versatile tool that has applications such as making grooves and recesses, chamfering, and engraving of inscriptions on the surface of the workpiece. Used for wood, soft and medium breeds, chipboard, aluminum, brass.
Profile of the bottom of the resulting recess has a V-shape. Therefore, these mills received the appropriate name. As in the case of mills for deep holes, the most common milling cutters with shank diameters 6 and 8 mm.
Full angle at the tip is 90°. Also this angle can be 30, 45 and 60° depending on the desired shape of the resulting faces and the hardness of the material. Sometimes to improve the wear resistance on the surface of the cutting edge is applied a special coating with a mixture of cobalt or molybdenum.
Groove for discharging shavings is usually performed straight. They faces are mutually perpendicular. However, in some versions one face is machined at an angle to the axis. This can improve the speed of chip removal from the cutting area.
the Cutter is made of tool alloy steel and cutting edges — carbide materials. This performance, coupled with the geometry of the cutter allows to reduce the radial runout. Therefore, these instruments are suitable for such works as chamfering and engraving of letters, where the precision machining plays a high role.
Processing pastavino cutter, usually occurs at high speeds of rotation of the spindle, reaching tens of thousands of rpm. It is inevitable rising temperatures as the workpiece and cutter to the critical values, which may result in the destruction of the workpiece in the cutting area. Therefore, it is necessary to organize cooling of the working area. This is done by using compressed air, emulsion of liquids.
In General, the selection pistolling cutters is dependent on the workpiece material and the size and desired shape of groove, groove.