DE102009037903A1 - Gear hob for producing e.g. gear wheels, has toothed ring comprising teeth in which insert seats are incorporated at both sides of tooth flanks by milling, where insert seats are provided for accommodating left and right cutting inserts - Google Patents

Abstract

The hob has single-piece base body comprising a hollow shaft (10) and a toothed ring (11) that runs in coil-shape and is triangular in cross-section. The toothed ring has 12 equally spaced teeth in which insert seats are incorporated at both sides of tooth flanks by milling, where the insert seats are provided for accommodating left and right cutting inserts. The teeth are separated by grooves, and the teeth and/or 5 to 20 cutting body rows are provided over a rotation angle of 360 degrees. The tooth flanks form an angle of 40 degrees.

Description

The The invention relates to a hob with indexable inserts.

hobs especially for the production of gears, racks, Worm wheels or other gearing parts needed. The hobs used are uniform a basic body on which individual tooth segments in one mounted thread-shaped guide of the body are and form a helically extending sprocket.

For example, in the DE 101 31 333 A1 Hob described which consist of a base body and individual cutting segments, each segment has three cutting teeth, between which grooves are arranged. In the case described there, a high-speed steel is selected as the material for such hobs and a cemented carbide for the segment material.

It are also known hobs, in which mounted on a basic body individual segments and in Each segment individual indexable inserts are arranged.

The DE 27 00 525 A1 describes a hob which has a mandrel on which a plurality of annular discs provided with helical sprockets are placed and secured against rotation. The annular discs lie with their plane-parallel surfaces together and serve as a carrier for indexable inserts.

As well are hobs are known in which for storage the indexable inserts are used cassettes, which are mostly still provide adjustments.

The However, described embodiments are very constructive elaborate and smaller for hobs Sizes not displayed.

It The object of the present invention is to remedy this situation.

to The solution is a hob with indexable inserts proposed, the one-piece manufactured body with a helical running and in cross section essentially triangular sprocket with teeth has, in each case on both sides of the tooth flanks insert seats are incorporated for receiving the indexable inserts, preferably by milling. Such a one-piece steel body with pre-milled insert seats is easy to handle and can be produced inexpensively. Under a Basic body is every cutting part with more than 2 cutting body rows also to understand such basic bodies, at their ends, d. H. outside the cuttable part, with others Components are connected.

As in principle known in the art, the teeth are each separated by V-shaped incisions. The opening angle of the V-cuts is between 40 and 50 °. The equally spaced teeth can chosen differently depending on diameter and machining task become.

It has been useful in practical experiments proved that the hob above a Rotation angle of 360 ° 8 to 24, preferably 12 evenly spaced Has teeth and / or 5 to 20 cutting body rows, However, there are other fittings or lengths conceivable. The pitch of the sprocket is at a concrete embodiment at a nominal inner diameter (measured at the lowest point of a V-shaped incision for opposite point) of 72 mm between 12 and 13 mm or at pitch angles between 2.5 and 2.6. The tooth flanks of a single tooth form an angle of 35 ° to 50 °, preferably 40 °.

in the concrete embodiment are alternately left and right on each tooth edge indexable inserts arranged. It is within the scope of the present invention also possible each tooth on the left as well as on the right 2 each one above the other To provide indexable inserts per tooth flank, which has the advantage can make it easier to design instead of a single complex shaped cutting insert and thus cheaper manufacturable cutting inserts whose Contour is circumferentially grindable, can be used.

Further Details of the hob are shown in the drawings explained. Show it:

1 a perspective view of a hob according to the invention,

2 a cross section through the hob, transverse to the longitudinal and rotational axis and

3 a detailed view of a tooth with two indexable inserts.

The core idea of the present invention is based on that of a hollow shaft 10 and the helical sprocket 11 existing body is made in one piece from a steel. The sprocket points at its two flanks 12 and 13 , which include an angle of 40 °, each formed by milling indexable insert seats with a support surface 14 and to support two sides of the indexable insert te a side surface 15 and a lower surface 16 on. The indexable inserts are over a fastening screw 17 , which passes through a central mounting hole fixed. In the illustrated case twelve teeth are provided at an equidistant distance over an angle of 360 °, by triangular incisions 18 are separated from each other. Each tooth carries an indexable insert 19 respectively. 20 , wherein the indexable inserts of successive teeth are arranged alternately, ie on different tooth flank sides. Each of the indexable inserts 19 . 20 has a substantially cuboid base body, on the upper side of a convex end face is formed, which together with a side surface of a convex cutting edge 21 forms. The total length of the hollow shaft is 140 mm with a diameter d (see 2 ) of about 35 mm. The width of the driving slot b is about 8 mm. As already mentioned, due to the equidistant arrangement of the cutting inserts the in 2 represented angle α 30 ° or the angle β from a cutting edge insert of a cutting insert on one side of the flank to the cutting edge of the next on the same edge cutting insert 60 °. The height of the sprocket, measured from the sheath 10 to the tip of a tooth is about 10 mm.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10131333 A1 [0003]
• - DE 2700525 A1 [0005]

Claims (6)

Hobs with indexable inserts ( 19 . 20 ), characterized in that the integral body ( 10 . 11 ) with a helically extending and in cross-section substantially triangular sprocket ( 11 ) Has teeth, in each of which the tooth flanks ( 12 . 13 ) Panel seats ( 14 . 15 . 16 ) for receiving the indexable inserts ( 19 . 20 ) are incorporated, preferably by milling. Hob according to claim 1, characterized in that the teeth are each formed by V-shaped cuts ( 18 ) are separated. Hobbing cutter according to claim 1 or 2, characterized in that over a rotation angle of 360 ° 8 to 24, preferably 12 equally spaced teeth and / or 5 to 20 cutting body rows are provided. Hobbing cutter according to one of claims 1 to 3, characterized in that a pitch of the toothed rim ( 11 ) between 12 and 13 mm and / or the pitch angle between 2.5 and 2.6 °. Hobbing cutter according to one of the claims 1 to 4, characterized in that the tooth flanks of a tooth form an angle of 35 to 50 °, preferably 40 °. Hob according to one of claims 1 to 5, characterized in that alternately left and right on each tooth flank ( 12 . 13 ) Indexable inserts ( 19 . 20 ) are arranged.

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