DE19609820A1 - Boring and milling tool which consists of cylindrical body with cutter bits - Google Patents

Abstract

The tool consists of a cylindrical main body (1) in the circumference of which at least three spiral chip clearance grooves are machined. Interchangeable cutter bits (3,4,4') are mounted on the sides of the spiral grooves. The lower cutting edges (6), of the lowest cutter bits (4) in the grooves, protrude slightly beyond other cutter bits (5,5') which are mounted on the end face of the tool. The lower cutter bits (4) in the grooves are circular. One of these cutter bits (4') is mounted on a slightly larger radius than the other cutter bits. The cutter bits (5') on the end face, which are mounted centrally, make an angle of 5 to 50 degrees with the cutter bits or the circumference.

Description

The invention relates to a drilling milling tool according to the Preamble of the main claim.

Such tools are used in particular in aircraft construction Manufacture of cassette-shaped milled workpieces Light metals used. You need both to drill into that full material as well as copy milling equally good be suitable.

DE-C2-32 09 821 and DE-U1-79 35 032 describe such Tools, the tool according to DE-C2-32 09 821 the external end cutting edge is lower than in the drilling direction the lowest point of the inner forehead edge, creating a very smooth bottom of the milled recess can be produced.

The disadvantage of these drilling and milling tools is that they only have two Chip flutes and thus only two rows cutting circumferentially Have indexable inserts, which increases the cutting performance the tools are not very good.

Furthermore, end mills are known which have more than two circumferences have spiral-shaped flutes, in each of which a series of axially offset indexable inserts are arranged. Both end mills were used the use of different insert shapes as also different types of arrangement of the  also different types of arrangement of the Inserts in the individual flutes per se or in successive flutes are proposed.

DE-A1-38 12 150, DE-A1-39 35 191 and DE-A1-41 37 230 describe, for example, end mills in this version. Such end mills have an excellent Cutting performance on. Since they usually have no face have center cutting inserts, they are however only for milling and not for drilling into the full Suitable material.

Attempts have also been made to use such end mills to provide indexable inserts to one To be able to drill into the full material. It did however, the removal of chips from the hole as problematic proven so that only holes with shallow depths are made that could be used in practice for most applications were not sufficient, so that such drilling-milling tools have not prevailed.

The object of the present invention is therefore a To create a milling tool for drilling into the full material is suitable and that over known such Milling tools significantly improved cutting performance and has improved chip evacuation.

According to the invention, this is achieved in that the drilling and milling tool has at least three flutes, that the indexable inserts ( 4 , 4 ') that cut simultaneously on the circumferential and end sides are designed as round inserts, the flight circle of the outermost cutting point ( 7 ) of the cutting edge of a round insert ( 4 ') is larger than those of the other round plate (s) ( 4 ) and the remaining circumferentially cutting indexable inserts ( 3 ) and that the front-side, center-cutting indexable insert ( 5 ') seen in front view, an angle ϕ between 5 ° and 50 ° with the indexable insert ( 3 ) closest to the circumference in the same cutting direction.

This special embodiment of the invention Smaller, but thicker chip segments are created with the tool. The chip becomes stiffer, tends to break and is therefore lighter from the hole or the flutes of the milling tool remove. The amounts by which the circumferential and frontal cutting inserts compared to the rest Inserts protrude radially and axially lies in the Practice in a range between 0.03 and 0.3 mm. Is essential in the tool according to the invention that two of the circumferential and front cutting inserts with round inserts the corresponding axial and radial projections will. The shape, number and arrangement of the rest Indexable inserts are responsible for the good machining behavior of the drilling-milling tool according to the invention only from of minor importance and can be at the discretion of the specialist according to known designs.

In a preferred embodiment of the drilling Milling tool it has four flutes and four in front  Radial overlapping inserts, two of which are designed as round plates, which in opposite flutes are arranged. With a Such an embodiment can in particular in practice particularly common diameter range of drilling Milling tools between 30 and 50 mm advantageously manufactured will. It makes sense for larger tool diameters be to increase the number of flutes while it is at smaller diameters will be advantageous, the number of Limit chip flutes to three, even for small ones A sufficiently good chip removal with sufficient diameter To allow stability of the tool.

In a further particularly advantageous embodiment of the Drilling-milling tool is the angle ϕ that the Indexable insert that cuts the center, with the in same cutting direction closest circumference cutting insert includes between 30 and 50 °. In this way it is particularly well achieved that the chip evacuation runs unhindered into the spiral flute, without the cross section for the cutting direction leading support section of the tool body for the corresponding leading indexable inserts becomes small.

Particularly good cutting results are achieved if the individual indexable inserts axial angle γp between 2 ° and 8 ° and have radial angles γf between -3 and + 3 °, the Side clearance angle α between 2 and 5 ° when installed  should lie. To make it even better and easier To achieve chip evacuation from the flutes, it is advantageous the shape of the indexable inserts Arrange recesses on the groove flank so that none protruding parts hinder the running chip.

In addition, it is important to remove the chips by To assist reflux from the well, being beneficial is when the coolant supply is inside Coolant channels are in the immediate vicinity of the emerge individual indexable inserts, in particular a Coolant channel directly to the main cutting edge of the center cutting insert is directed.

Furthermore, it is advantageous if in the drilling Milling tool the individual flutes in unequal Angular distances from each other are incorporated, creating a particularly soft, chatter-free machining is made possible.

In the following, the invention will be explained in more detail with reference to figures explained.  

Show it

Fig. 1 shows an inventive drilling milling tool in side view,

Fig. 2 shows the drilling cutting tool of Fig. 1 in end view,

Fig. 3 shows the front end of the drilling-milling tool according to FIG. 1 in an enlarged view.

The Figs. 1 to 2 illustrate an inventive drilling milling cutter having four helically in the periphery of the milling body 1 incorporated flutes. 2 In a flank of the flutes 2 pocket-shaped recesses for the positive reception of the inserts 3, 4, 4 ', 5 are incorporated. The center cutting insert 5 'is fixed in a recess of the flute 9 , which opens obliquely into a flute 2 . The only circumferential inserts 3 are designed as parallelogram-shaped positive inserts, the individual inserts 3 of successive flutes 2 being axially offset from one another such that a continuous and uninterrupted cutting line is formed with a slight overlap of the individual cutting edges. The indexable inserts 3 of the remaining two flutes 2 are arranged in the same way, the indexable inserts 3 of opposing flutes 2 each being arranged at the same axial height. In this way, two continuous but interrupted circumferential cutting lines are formed in the drilling-milling tool according to the invention with four spiral flutes. The indexable inserts 4, 4 'of two opposing flutes 2 , which cut both on the circumferential side and on the end face, are designed as round inserts. The front-side cutting inserts 4, 4 ', 5, 5' are arranged offset from one another so that the cutting edges of all inserts form a continuous but interrupted cutting line with slight mutual overlap, which extends beyond the longitudinal axis A of the milling tool 1 . In this way, the tool according to the invention is also suitable for drilling into the full material. As can be seen specifically from FIG. 3, in the drilling-milling tool according to the invention, the deepest point 6 of the round plate 4, which simultaneously cuts on the circumferential and frontal sides, is lower in the drilling direction than the deepest points of the cutting edges of the remaining end-cutting inserts 4 ', 5, 5 ' . At the same time, the radially outermost point 7 of the cutting edge of the simultaneously round and end cutting round plate 4 ' compared to the radially outermost points of the cutting edges of the remaining circumferentially cutting indexable inserts 3 , 4 is arranged radially the farthest laterally. The front, the center cutting indexable insert 5 ' is square and seen in front view includes an angle ϕ of 35 ° with the closest circumferential indexable insert 3 in the same cutting direction. With these special arrangements of the front and circumferential cutting inserts, optimal chip formation and good removal of the chips from the chip flutes during machining, even with large drilling depths, is guaranteed.

Claims (8)

1.Bore-milling tool with a milling cutter body ( 1 ), in the circumference of which several chip flutes ( 2 ) arranged at certain angular intervals are incorporated, in which axially overlapping cutting inserts ( 3 , 4 , 4 ') are attached in a spirally offset manner and several at the end , in the radial direction overlapping cutting inserts ( 4 , 4 ′, 5 , 5 ′), of which a part ( 4 , 4 ′) also cuts circumferentially at the same time, viewed in side view, the lowest cutting point of the cutting edge at one ( 4 ) of the indexable inserts ( 4 , 4 ') which cut at the end and circumference at the same time overhangs the lowest cutting points of the remaining indexable inserts ( 4 , 5 , 5 '), characterized in that the milling tool ( 1 ) has at least three flutes ( 2 ) in that the indexable inserts ( 4 , 4 ′) al s round plates are executed, the flight circle of the outermost cutting point ( 7 ) of the cutting edge of a round plate ( 4 ') is larger than that of the other round plate (s) ( 4 ) and the remaining circumferential cutting inserts ( 3 ) and that the front , the center-cutting indexable insert ( 5 ') seen in front view, an angle ϕ between 5 ° and 50 ° with the closest circumferential indexable insert ( 3 ) in the same cutting direction. 2. Drilling and milling tool according to claim 1, characterized in that the milling tool has four flutes ( 2 ) and four radial overlapping cutting inserts ( 4 , 4 ', 5 , 5 '), two of which ( 4 , 4 ') ) are designed as round plates, which are arranged in opposite flutes ( 2 ). 3. Drilling and milling tool according to claim 2, characterized in that the angle ϕ the indexable insert ( 5 ') which the center machined with the closest circumferential cutting insert ( 3 ) in the same cutting direction includes between 30 ° and 50 °. 4. drilling-milling tool according to one of claims 1 to 3, characterized in that the individual indexable inserts ( 3 , 4 , 4 '' 5 , 5 ') axial angle γp between 2 ° and 8 ° and radial angle γf between -3 ° and + 3 °. 5. drilling-milling tool according to one of claims 1 to 4, characterized in that the indexable inserts ( 3 , 4 , 4 ', 5 , 5 ') have a side clearance angle α between 2 ° and 5 ° in the installed state. 6. Drilling-milling tool according to one of claims 1 to 5, characterized in that the indexable inserts ( 3 , 4 , 4 ', 5 , 5 ') are arranged in the shape of the indexable inserts corresponding recesses. 7. drilling-milling tool according to one of claims 1 to 6, characterized in that the tool has internal channels for coolant supply, the outlet openings ( 8 , 8 ') emerge in the immediate vicinity of the indexable inserts and wherein an outlet opening ( 8 ') on the main cutting edge the front, the center cutting indexable insert ( 5 ') is directed. 8. Drilling and milling tool according to one of claims 1 to 7, characterized in that the individual flutes ( 2 ) are incorporated at unequal angular distances from one another in the basic cutter body ( 1 ).