RU158628U1 - END MILL WITH CHANGEABLE CUTTING PLATES WITH HIGH RESISTANCE - Google Patents

Abstract

An end mill with interchangeable cutting inserts, comprising a shank, a cylindrical cutting part with a diameter D and an end plane, having helical L-shaped grooves with mutually perpendicular sides, one of which is a working one and contains a plurality of interchangeable radial cutting inserts fixed with screws along the diameter of the cylindrical part, made with side cutting blades, while the extreme of these inserts are end cutting plates, have end cutting blades and are fixed to the end plane and milling cutters, characterized in that it is provided with fixed screws on the non-working side of said groove with additional end cutting inserts made with side and end cutting blades forming a cylindrical cutting part located along the diameter D of the cylindrical cutting part of the cutter and an end cutting part located at the end plane of the cutter, while under the additional end cutting inserts there are linings 4 mm thick.

Description

FIELD OF TECHNOLOGY TO WHICH A USEFUL MODEL IS.

The utility model relates to cutting tools for metal working, in particular to end mills with interchangeable cutting inserts for machining planes, grooves, steps in the manufacture of machine parts, including end mills with helical teeth with interchangeable carbide cutting inserts.

BACKGROUND OF THE INVENTION

A common known disadvantage of end mills is that end cutting teeth or end cutting inserts have a durability of approximately two times less compared to side cutting blades or radial cutting inserts.

This applies to all traditional standard end mills; GOST 28709-90 End mills with an elongated working part and helical teeth with replaceable carbide inserts; GOST 20537-75 End mill with soldered screw carbide inserts; GOST 87620-69 End mill with carbide crowns; TU2-085-591-77 End mill with soldered straight carbide inserts.

The end part of the cutter weakened by the condition of resistance determines the resistance of the cutter as a whole, although the central part of the cutter remains operable and practically not worn out.

The disadvantage of standard end mills, consisting in the fact that end cutting blades wear out faster is known for a long time. The elimination of this drawback is carried out along the path of increasing durability, through the integrated use of wear-resistant coatings, the most susceptible to wear of the tooth section at the end face of the cutter. This is evidenced by the following works: Kurochkin A.V. Improving the performance of carbide end mills by optimizing the architecture of multilayer nanostructured wear-resistant coatings. Abstract for the degree of candidate of technical sciences. Rybinsk State Aviation and Technology University named after P.A. Solovyov 2012, 26 p. (on page 16); Certificate of registration of intellectual property 10-277. Design and manufacture of wear-resistant coatings for carbide cutting tools used for machining parts of gas turbine engines from difficult to process materials, D.I. Volkov, V.I. Poletaeva V.V. Makhryutin, A.V. Kurochkin, M.O. Mezentsev. 2010.

In the utility model No. 125502 V23C 5/10 07/19/2012. “End mill of increased resistance” (Authors Cherkashin VP, Vodilov AV) the increase in resistance is achieved by installing additional teeth in the end part of the mill. Additional teeth take on part of the cutting work and increase the resistance of the cutter in the end part and, therefore, increase the resistance of the cutter as a whole.

In the proposed utility model, the milling cutter according to GOST 28709-90 “End mills with an elongated working part and helical teeth with replaceable carbide inserts” was taken as a prototype. In the proposed utility model, an increase in resistance is also achieved by installing additional teeth or cutting inserts in the end plane of the cutter. But structurally, the cutter in utility model No. 125502 and the proposed utility model have completely different designs and there are not even common ground here. Structurally, the milling cutter in utility model No. 125502 contains a nape (protrusions on the body of the milling cutter) and hard-alloy straight cutting inserts (teeth) are soldered to these naps; additional teeth are oblique cutting inserts that are soldered between the nape of the neck. In a utility model, the prototype of which is a milling cutter with interchangeable cutting inserts according to GOST 28709-90, has a completely different design. This end mill with interchangeable cutting inserts has helical L-shaped grooves with mutually perpendicular sides, in which one side of the groove is working and contains a plurality of interchangeable cutting inserts fixed with screws along the diameter of the cylindrical part. To install additional plates here, one needs to invent a constructive method that allows this installation to be implemented

It should be noted a distinctive feature of the end mill GOST 28709-90, although this is not directly related to the principle of the proposed utility model. Replaceable cutting inserts are staggered (there is no solid cutting blade here). Replaceable cutting inserts are distributed to ensure mutual overlap during cutting. A part of the metal was cut by plates installed in one groove (a groove with installed plates in this mill is a tooth) is cut off as the mill rotates with plates installed in another groove. This is done in order to reduce the circumferential cutting force.

The end mill GOST 28709-90 is a prototype of a utility model.

The disadvantage of the prototype is the unused reserve for increasing resistance due to uneven wear of the side and end cutting blades, as the end cutting blades wear out twice as fast and determine the resistance of the cutter as a whole.

The purpose of the utility model is to eliminate the disadvantages of the prototype. This is achieved as follows.

An end mill with interchangeable cutting inserts, comprising a shank, an end face of the mill, a cylindrical cutting part having helical L-shaped grooves with mutually perpendicular sides, in which one side 4

the groove is working and contains the diameter of the cylindrical part, many fixed by screws and having only side cutting blades interchangeable radial cutting plates, the last of which, having both side and end cutting blades, are end cutting plates and are mounted at the end plane of the cutter, characterized in that on the other, non-working side of the groove, additional end cutting inserts are installed and fastened with screws having both side and end cutting blades, the end part of which is located at the end plane milling cutters, and the cylindrical cutting part of which is located on the diameter of the cylindrical cutting part of the cutter, and under these additional cutting inserts there are pads, the thickness of which is determined depending on the operating conditions of the cutter.

The following patents are analogues of the utility model.

Patent No. 2348492 В23С 5/10 09/17/2004. Rotary tool having irregular orientation of insert cutting inserts.

Patent No. 2463134 В23С 5/20 02/17/2009. Spiral cutter.

Patent No. 2507038 В23С 17.06. 2004. End mill for processing difficult materials.

Utility model patent No. 138782 В23С 2.10.2013. Milling-cylindrical.

The inventions (RF and foreign), which are referred to in the mentioned patents, also serve as analogues of the utility model.

DISCLOSURE OF A USEFUL MODEL.

The end mill according to GOST 28709-90 "End mills with an elongated working part and helical teeth with replaceable carbide inserts" is adopted as a prototype of the proposed utility model.

The technical result consists in increasing the resistance of the cutter by ensuring uniform wear of the side and end cutting blades of the cutter.

This is achieved as follows.

An end mill with interchangeable cutting inserts containing a shank, an end face of the mill, a cylindrical cutting part having helical L-shaped grooves with mutually perpendicular sides, in which one side of the groove is working and contains a plurality of cylindrical parts fixed with screws and having only side cutting blades interchangeable radial cutting inserts, the last of which having both side and end cutting blades, 5

They are end cutting inserts and are mounted at the end face of the cutter, characterized in that on the other, non-working side of the groove, additional end cutting inserts are installed and fastened with screws, both end and end cutting blades, the end part of which is located at the end face of the cutter, and the cylindrical cutting part which is located on the diameter of the cylindrical cutting part of the cutter, and under these additional cutting plates there are pads, the thickness of which is determined depending on the high-performance milling cutters.

The screw grooves in this milling cutter are rectangular. This is necessary so that there is easy access for the convenience of manufacturing fixtures of cutting inserts on the working side of the groove; drills, reamers, swords, screwdrivers during operation are parallel to the non-working sides of the groove and therefore there is no difficulty when working with these tools. The non-working side of the groove is perpendicular to the working side of the groove; There is a technological demand for this. After making mounting fixtures for the plates on the working side of the groove, the non-working side of the groove is not in principle demanded and there is free space for accommodating an additional end cutting insert. This is used in the proposed utility model.

A lining of thickness h under additional special cutting inserts is needed to improve chip removal from the cutting zone. The lining lifts the cutting insert and a space is created under it to accommodate the chips.

Chips can be different depending on the milled metal.

When processing brittle metal, for example cast iron, there is a breakage chip that crumbles immediately in the cutting zone.

When milling conventional engineering steels (steel 45 HB180-217, steel 40X HB2431-285 GOST 4543-71), as well as hard-to-work steels (steel 40XH2MA, 18X2H4MANV 300-320 GOST 4543-71), shear chips are obtained. Chipping chips have the appearance of a continuous tape, but when in contact with a solid obstacle, that is, with a little effort on it, it immediately crumbles into separate small fragments. With such shavings, it is necessary so that fragments of shavings are placed under this lining before this shavings move along the cutting 6

the blades mounted on the screw grooves fall into the area where there are no additional end cutting inserts and where there is enough space to accommodate the chips.

But during the processing of soft and viscous metals (steel 08 HB 110-150, steel 10 HB137-160, steel 20 HB123-167, steel 30 HB143-170 GOST 4543-71), drain chips are obtained. The discharge chip is in the form of a continuous tape, and if there is not enough space for its placement, this chip is strongly deformed, but does not break up. With this type of shavings, a lining with a thickness of approximately h = 4 mm is advisable.

Thus, the lining with a thickness of h = 4 mm is suitable for any chip, in the processing of typical engineering steels and in typical milling modes, but nevertheless, the following must be taken into account. The final value of h is taken into account the specific conditions of production, since steel may not be typical and processing modes may not be typical with all the variety of technological processes in industry.

It should be noted that when changing the thickness of the lining, it is necessary to change the thickness of the insert, otherwise the cylindrical cutting part of the additional special end cutting insert will not be on the diameter of the cylindrical cutting part of the cutter,

The difference between the utility model and the prototype is that on the other, non-working side of the screw groove, additional special end cutting inserts are installed and fastened with screws, both the end and end cutting blades, the end part of which is located at the end plane of the cutter, and the cylindrical cutting part of which is located on the diameter of the cylindrical cutting part of the cutter, and under these additional cutting inserts there are pads, the thickness of which is determined depending on the operating conditions of the fr PS; this is an essential feature of a utility model.

Objectively manifested technical result consists in increasing the resistance of the end mill. The increase in resistance is achieved by installing additional cutting inserts in the end of the cutter. Additional cutting inserts take on part of the cutting work and increase the resistance of the cutter in the most wear zone, that is, in the end part and, therefore, increase the resistance of the cutter as a whole.

The length of the additional end cutting inserts may be less than the length of the end plates, but the length of the cylindrical cutting part 7

additional cutting inserts should not be less than 2 mm (as a reserve when grinding the inserts at the end).

BRIEF DESCRIPTION OF THE DRAWINGS

The proposed utility model is shown in FIG. 1-7, on which:

in FIG. 1 shows a general view of an end mill with interchangeable cutting inserts;

in FIG. 2 shows a view of the end mill from the end part;

in FIG. 3 shows a view along section AA; the cross section passes through the end cutting inserts and through the additional end cutting inserts;

in FIG. 4 shows a view along section BB; the cross section passes through the end cutting inserts;

in FIG. 5 shows a side view of an additional face cutting insert;

in FIG. 6 shows an end view of an additional end cutting insert;

in FIG. 7 shows the chips removed by an additional end cutting insert,

IMPLEMENTATION OF A USEFUL MODEL

An end mill with interchangeable cutting inserts, comprising a shank 1, an end plane of the mill 2, a cylindrical cutting part 3 of diameter D, having helical L-shaped grooves with mutually perpendicular sides 4 and 5, in which one side of the groove 4 is working and contains the diameter of the cylindrical part many fixed with screws 6 and having only side cutting blades 7 interchangeable radial cutting plates 8, the last of which having both side 9 and end 10 cutting blades, are end cutting plates 11 and are mounted at the end the plane of the cutter 2. On the other, non-working side of the groove 5 are installed and fastened with screws 12 with both side 13 and end 14 cutting blades additional end cutting inserts 15, the end part of which is located at the end plane of the cutter 2, and the cylindrical cutting part of which is on diameter D the cylindrical cutting part of the cutter, and under these additional cutting inserts there are pads 16, the thickness h of which is determined depending on the operating conditions of the cutter.

Additional cutting inserts take on part of the cutting work and increase the resistance of the cutter in the most wear zone, i.e. in 8

end part and, therefore, increase the resistance of the cutter as a whole. The resistance of the cutter is approximately doubled. The number of teeth in the front part of the utility model is twice as large as in the prototype.

In order to prevent chip shavings in the cutting zone of additional cutting inserts, underlaying plates with a thickness of h = 4 mm are installed under these inserts, which are suitable for all types of shavings (drainage chips, chipping and chipping) with cutter diameters D = 100 mm and less (up to D = 100 mm).

The angular distance in the end part of the milling cutter between all cutting inserts (including end cutting inserts 11 and additional cutting inserts 15) are the same.

Space A in FIG. 7 between the cutting part of the additional cutting insert 5, the lining 6 and the cutter body 3, is a chip groove in which fragments of chip 18 are placed before this chip moving along the cutting blades mounted on the screw grooves enters the area where there are no additional face a cutting insert and where there is enough space to accommodate the chips.

If the volume of space A is insufficient, then the chips will become stuck in the cutting zone and scratch the treated surface 17, reducing its cleanliness.

The end mill during milling can be in a horizontal position (as shown in Fig. 1), in a vertical position, that is, with the end part down) and in an inclined position.

In the presence of L-shaped grooves with mutually perpendicular sides, the manufacture of mounts for additional end cutting inserts on the non-working side of the groove is not difficult; installation and replacement of cutting inserts is not difficult.

In typical cutting conditions, the chip thickness has a thickness of K = 0.1 mm (when feeding S = 0.1 mm / tooth and a mill diameter of D = 100 mm) in the middle part of the mill and K1 = 0.05 mm in the end part of the mill, where the number of teeth is twice as large. But with such a relatively small thickness, the chip deforms into an annular shape, and a chip groove is needed to accommodate it.

The disadvantage of standard end mills, consisting in the fact that end cutting blades wear out faster is known for a long time. The elimination of this drawback is 9

ways to increase resistance, through the integrated use of wear-resistant coatings, the most susceptible to wear of the tooth section at the end face of the cutter. This is evidenced by the following works: Kurochkin A.V. Improving the performance of carbide end mills by optimizing the architecture of multilayer nanostructured wear-resistant coatings. Abstract for the degree of candidate of technical sciences. Rybinsk State Aviation and Technology University named after P.A. Solovyov 2012, 26 p. (on page 16); Certificate of registration of intellectual property 10-277. Design and manufacture of wear-resistant coatings for carbide cutting tools used for machining parts of gas turbine engines from difficult to process materials, D.I. Volkov, V.I. Poletaeva V.V. Makhryutin, A.V. Kurochkin, M.O. Mezentsev. 2010.

In the proposed utility model for an end mill with interchangeable cutting inserts, an increase in resistance is obtained by changing the design of the mill.

As a result of changing the design of the cutter, the resistance of the end part of the cutter containing the end cutting inserts 11 and additional special cutting inserts 15 is increased.

End milling is mainly focused on CNC machines. On these machines, one end mill can handle not only different parts, but also different surfaces and structural elements in one part. When milling, not only the radial cutting inserts 8 are involved in the cutting, but also the inserts 11 and 15 of the end part of the mill.

In this case, the inserts of the end part of the mill are loaded with forces much more often than the radial cutting inserts.

End mills are extremely sensitive to fluctuations in cutting forces due to the possibility of vibrations. Therefore, it is advisable to process deep grooves with a large milling width in several passes (after each pass, deepening the cutter) because of the risk of vibrations. Processing in several passes is also carried out in those cases when the strength of the mill body is insufficient, as well as when the machine power is insufficient. When milling with a long overhang, processing is also performed in several passes. In all these cases, the plates of the end part of the mill are predominantly loaded.

When processing shallow grooves and closed keyways, milling with axial feed is used. Circular interpolation milling with 10

axial feed cutting is used for processing wide grooves and pockets. In these cases, the end part of the cutter is also predominantly loaded.

The last finishing pass (semi-finishing or finishing) is made when removing a small allowance. Milling cutters, when removing a small allowance, can process the part to the full milling width under stable cutting conditions without vibrations. Only in this case are the plates of the end part of the cutter 11 and 15 and the radial plates of the cutter 8 loaded.

The installation of additional cutting inserts 15 implies the formation of a socket, threading under the screws and centering either in the socket or by means of screws (without forming a socket), which does not affect the very principle of the utility model.

BIBLIOGRAPHY

GOST 28709-90 End mills with an elongated working part and helical teeth with replaceable carbide inserts.

Utility model No. 125502 V23C 5/10 07/19/2012. End Mill High Strength.

Patent No. 2348492 В23С 5/10 09/17/2004. Rotary tool having irregular orientation of insert cutting inserts.

Patent No. 2463134 В23С 5/20 02/17/2009. Spiral cutter.

Patent No. 2507038 В23С 15.06. 2004. End mill for processing difficult materials.

Utility model patent No. 138782 В23С 2.10.2013. End mill cylindrical.

GOST 20537-75 End mill with soldered helical carbide inserts.

GOST 87620-69 End mill with carbide crowns.

TU2-085-591-77 End mill with soldered straight carbide inserts.

Claims (1)

An end mill with interchangeable cutting inserts, comprising a shank, a cylindrical cutting part with a diameter D and an end plane, having helical L-shaped grooves with mutually perpendicular sides, one of which is a working one and contains a plurality of interchangeable radial cutting inserts fixed with screws along the diameter of the cylindrical part, made with side cutting blades, while the last of these inserts are end cutting plates, have end cutting blades and are fixed at the end plane f cuts, characterized in that it is provided with fixed screws on the non-working side of said groove with additional end cutting inserts made with side and end cutting blades forming a cylindrical cutting part located along the diameter D of the cylindrical cutting part of the cutter and an end cutting part located at the end planes of the cutter, while under the additional end cutting inserts there are linings 4 mm thick.

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