DE20307208U1 - Machine tool with reversible cutting blade, comprising fixing arrangement with two slots and tongue-shaped extension - Google Patents

Abstract

The cylindrical tool (1) is provided with a recess (2) in the shape of a quarter-circle and with a scale (7) printed on its upper surface, which has a plane bottom for the accommodation of the reversible cutting blade (5). An extension (9) is guided from one side of the blade (5) into a horizontal slot (6) and is locked by a screw (15), inserted into a vertical bore, intersecting with the horizontal slot (6).

Description

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End mills

The invention relates to an end mill designed as a single-edged end mill equipped with indexable inserts for face milling and roller milling, for chamfering and countersinking for use in metalworking.

&iacgr;&ogr; Such known milling cutters for different milling angles differ in that indexable inserts of the most varied shapes are fixed in corresponding positions on the base body of the milling cutter and the position of the indexable inserts is determined by holding surfaces on which edge areas of the indexable inserts attached to the base body rest.

Due to the different positions of the holding surfaces, a base body is required for each milling angle.

To avoid this, either indexable inserts are inserted into angle-adjustable cassettes that are connected to the base body or angle adjustments are made possible by exchanging the cassettes, with each cassette realizing a predetermined angle of attack.

DE 197 35 442 A1 discloses a face or corner milling cutter with indexable insert cassettes, which has a cutter head as a base body with cassettes provided at intervals around its circumference for holding indexable inserts in guides.

The indexable insert cassettes are each mounted at a centre of gravity with an axis perpendicularly penetrating the contact plane on the base body in

adjustable between 0 degrees and a specified angle range (α) and can be fixed with the insertable indexable inserts by means of a common clamping element without replacing a component.

Each indexable insert cassette is designed with a peripheral surface concentric with the center of gravity, in which recesses are provided for exact angular positioning &iacgr;&ogr;, and contains a locking element at the bottom of each guide of the base body designed for an indexable insert cassette, which interacts with a recess on the peripheral surface of the cassette.

The disadvantage of this solution is that although different angles can be set, these are predetermined by the recess on the peripheral surface of the cassette.
Continuous adjustment is not possible at this point.

Furthermore, a cassette for fastening an indexable insert to a milling tool is known from DE 43 00 289 A1. The cassette is used for the detachable fastening of an indexable insert to the base body of a face and corner milling cutter. It is designed with a nest for holding the indexable insert in a specific position and with a contact surface for positioning the nest in a defined position relative to the base body.

In order to fix the cassette in different angle positions, a positioning pin is located in the base body under the cassette at a certain distance from the swivel axis, indicated at position 12, which engages in a suitable hole in the bottom of the cassette. With reference to the swivel axis, two further pin holes with the same radius, but offset by 15° or 45°, are provided.

diameter. Depending on which of the three pin holes the positioning pin is engaged with, the milling cutter has a milling angle of 90°, 75° or 45° as shown in Fig. 1.

The disadvantage of this solution is that a continuous angle adjustment of the indexable insert is not possible. The previously known solutions also have the disadvantage that they are very complex both in terms of construction and manufacturing technology.

The invention is based on the object, starting from the prior art, of further developing an end mill of the type mentioned in the preamble of claim 1 in such a way that the setting angle of the indexable insert can be adjusted continuously, i.e. in accordance with a degree division, with little tool assistance, whereby the design and manufacturing effort for the shaft body is to be minimized.

The above object is achieved according to the invention in that the cylindrical base body is designed with a slot in its front part, the upper section of which has an approximately quarter-circle-shaped recess, the lower section forms a support surface for the indexable insert and both sections can be clamped against one another, a contact piece being provided for fixing the position of the indexable insert, which can be clamped with its tongue-shaped attachment between the upper and lower sections of the slotted front part of the base body.

On its side facing the indexable insert, the contact piece has an area with approximately the same thickness as the indexable insert.

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On the opposite side, this area is circular, with the radius corresponding to the radius of the recess.

The tongue-shaped attachment adjoining this area is slightly smaller in height than the slot height.

The underside of the indexable insert rests directly on the lower section of the cylindrical base body, without the usual leveling in a cassette as an intermediate layer. The position is fixed, including the anti-twisting protection of the indexable insert in the base body of the end mill, by the contact piece, which is rotatably guided and clampable in the slotted base body, with part of the circumference of the indexable insert resting on its contact side.

The indexable insert is fastened in its central bore by means of a screw on the lower section of the slotted base body and is thus secured against displacement in a form-fitting and force-fitting manner.

The principle of the invention will be explained in more detail using an embodiment and the associated drawings.
This shows

Figure 1: an end mill with attached

Indexable insert in two views

Figure 2: an end mill without indexable insert

in two views

II S ··· S · ·

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Figure 1 shows an end mill in a side and a top view.

The milling cutter base body 1 has an approximately quarter-circle-shaped recess 2 in its front area. The lower section 3 is machined flat and forms the support surface 4 for the indexable insert 5. This support surface 4 is continued to the rear as a slot-shaped recess 6 in the base body 1.

A scale-like graduation 7 is applied to the recess 2 extending towards the upper edge of the front area.

Furthermore, a threaded hole 8 is provided in the support surface 4 for fastening the indexable insert 5.

The position of the indexable insert 5 is fixed by means of a support piece 9. This support piece 9 has a tongue-shaped projection 10.

This tongue-shaped projection 10 is slightly smaller in height than the slot 6 provided between the upper section 11 and the lower section 3. The tongue-shaped projection 10 is inserted into this slot 6.

From below - at an angle of 90° to the slot 6 - a threaded through hole 12 is made, into which a clamping screw 13 is screwed in such a way that the upper section 11 is pulled onto the tongue-shaped projection 10 of the contact piece 9 and the contact piece 9 is thus firmly clamped.

The contact piece 9 has, on the side facing the indexable insert 5, a straight region with approximately the same thickness as the indexable insert 5.

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In contrast, the opposite side is curved, with the radius corresponding to the radius of the recess 2.

Furthermore, a marking 14 is applied to the top of the contact piece 9 on the opposite side, at an angle of 90° to the straight side facing the indexable insert 5, which forms the center with which the predetermined number of degrees can be set before the contact piece 9 is clamped.

The indexable insert 5 is thus firmly locked at the specified angle and fastened with the fastening screw 15.

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List of reference symbols

1 - Milling cutter body

2 - Recess

3 - lower section &iacgr;&ogr; 4 - support surface

5 - Indexable insert

6 - Slot

7 - Grading

8 - Threaded hole 9 - Support piece

10 - tongue-shaped attachment of the attachment piece

11 - upper section

12 - Through hole

13 - Clamping screw 14 - Marking

15 - Fixing screw for indexable insert

Claims (2)

1. End mill for face and roll milling, which is equipped with at least one indexable insert, the setting angle of the indexable insert being continuously adjustable from 0 to 90 degrees by turning it around its center in the milling cutter base body and the indexable insert being able to be fastened in its center hole by means of a screw, characterized in that the cylindrically designed milling cutter base body ( 1 ) has a slot-shaped recess ( 6 ) in its front part, the upper section ( 11 ) of which has an approximately quarter-circular recess ( 2 ), the lower section ( 3 ) forms a support surface ( 4 ) for the indexable insert ( 5 ) and both sections ( 11 and 3 ) are braced against one another, a support piece ( 9 ) being provided for fixing the position of the indexable insert ( 5 ), which with its tongue-shaped projection ( 10 ) is located between the upper and lower sections ( 11 and 3 ) of the slotted front part of the base body ( 1 ). 2. End mill according to claim 1, characterized in that the contact piece ( 9 ) has on its side facing the indexable insert ( 5 ) a region with approximately the same thickness as the indexable insert ( 5 ), this is circular on the side facing away, the radius corresponding to the radius of the recess ( 2 ) and the adjoining tongue-shaped projection ( 10 ) is slightly smaller in height than the height of the slot ( 6 ).