DE2746516C3 - Drilling jig for making a die - Google Patents

Description

The invention relates to a drilling jig for producing a cutting tool as is generally used for production of external threads is used, consisting of a cylindrical body, which with several im Distance around the longitudinal axis of the body evenly distributed guide holes is provided and on one end portion has a central externally threaded threaded pin ai 'which extends into a centric internal thread of the die can be screwed in.

In the production of such a die, difficulties arise in particular, that the recesses for the chip flow can be incorporated only with great difficulty and their free Edges, which largely determine the rake angle, can easily break out because the drill used for the Incorporation of these recesses used is not exactly can be performed.

From FR-PS 5 39 207 it is already known to use a drilling jig for producing a cutting tool to provide a threaded pin, which is used for alignment in an existing thread of the die body can be screwed in. With this known proposal, however, the above-mentioned Do not solve problems, because the holes to be made there are not used to make the recesses for chip evacuation.

The object on which the present invention is based is to provide a drilling jig for production to create a die, with the help of which on easy way the recesses for the chip discharge. without further reworking of the die «, to make necessary, can be incorporated exactly.

This object is achieved in that the threaded pin has a length that of the Thickness of the die to be produced corresponds, and that this threaded pin on its circumference through Extension of the guide holes in the cylindrical Has body formed recesses.

It is useful to have four guide holes in the Drilling jig provided, especially the outer jacket of the Body can be partially flattened.

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45 When machining holes on only part their scope, due to the fact that the material on the rest of the circumference of the bore is missing, it is already known in principle to support the drilling tool to be carried out on this missing circumference by means of a correspondingly recessed drilling jig. A However, direct reference to a generic drilling jig could not be obtained as a result.

The main advantage of this inventive design of a drilling jig is that the through the drilling jig extending guide holes serve as guides for the drill, which from above is inserted into the drilling jig when its threaded pin is in a central threaded hole in the one to be finished Die is screwed in. The recesses for the Chip evacuation worked out exactly in the die without running the risk of damaging the edges these recesses, the diameter of which is directly related to the rake angle, break out or run obliquely.

A drilling jig is created that is not technically complex and is particularly good for Production of dies is suitable, which have more than two recesses for the chip flow.

The invention is explained in more detail below using an exemplary embodiment on Ha.'d of the drawing. In the drawing shows

F i g. I a top view of a drilling jig,

F i g. 2 the in F i g. I shown drilling jig in side view.

F i g. 3 a using the drilling jig according to FIG. 1 die produced.

As shown in the drawing, the drilling jig a cylindrical body 1. which is provided with a central external thread at one end portion Threaded pin 2 carries. In the embodiment the body 1 and the threaded pin 2 are formed in one piece. Also is the threaded stem so long that its length corresponds essentially to the thickness of the die to be produced

Through the drilling jig, guide bores 3, 4, 5 and 6 extend around the central axis of the The drilling jig should be evenly spaced from one another.

The threaded pin points on its outer circumference in the area of these Kührungsbohrungen recesses.

As can be seen in particular from Fig.), The Thread / apfen 2 sin cross-sectional profile. whose Diameter is reduced by the corresponding proportion of the guide bores 3 to 6. These Guide bores extend through the cylindrical body 1 to the free end of the threaded pin 2.

When completing a die, the The drilling jig with its threaded pin 2 is initially screwed into a central threaded hole of the die and thus fixed.

Then a drill with a suitable diameter is inserted into each guide pin from the side shown on the right in Fig. 2 and uses it to drill the recesses a in the die attached to the drilling jig, the rake angle γ shown in direct relation to the diameters c / and c / "(Fig. 3).

Dii the drill from each pilot hole in the There is no danger of the drilling jig being precisely guided through the die while it is moving.

dsB break out the edges of the chip drainage recesses or are inclined to the longitudinal axis or improperly formed. The correct cutting angle γ is thus achieved directly because the cutting edges of the cutting tool are protected by being supported on the borehole gauge during drilling.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1. Drilling jig for making a die, consisting of a cylindrical body, which with several guide bores evenly spaced around the longitudinal axis of the body is provided and at one end portion a central threaded pin with an external thread has, which can be screwed into a central internal thread of the die, thereby characterized in that the threaded pin (2) has a length which is the thickness of the to be produced Die corresponds to, and that this threaded pin (2) on its circumference Extension of the guide holes (3,4,5,6) in the is has cylindrical body (1) formed recesses 2. Drilling jig according to claim 1, characterized in that four guide bores (3 to 6) are provided and that the outer jacket of the cylindrical body is partially flattened.