RU151511U1 - COMBINED AXIAL TOOLS FOR HOLE PROCESSING - Google Patents

Abstract

Combined axial tool for machining holes, consisting of a shank and a working part containing a drill with three cutting edges and three straight chip grooves and a tapping tap, made in one piece with each other, characterized in that the working part from the shank is made in in the form of a cylindrical countersink for making recesses for bolts with countersunk heads.

Description

The utility model relates to the field of metal working, namely to combined tools for drilling holes with additional hole processing operations.

Known combined axial tool for machining holes (DE No. 3627798, B23G 5/20, 02/18/1988), consisting of a shank and a working part containing a drill with two cutting edges and straight chip grooves, as well as a tapping thread made in one whole with each other. With this device, you can drill and cut a hole for the bolt in one pass, without changing the tool. In conditions of mass production, when the assembler has to install dozens of bolts per hour during the working day, the combined axial tool provides significant savings in working time. But then, when it comes to installing bolts with countersunk heads, the recesses for these heads have to be performed with another tool, spending additional time to change the tool.

In addition, the shape of the drill leaves much to be desired. If there are only two cutting edges during drilling and threading in metal parts, too much force is applied to each working edge of the drill. And in the lower end of the double-edged drill between the cutting edges there is a jumper that compresses the metal, causing increased contact stresses in it. All this leads to intensive wear of the edges of the drill, and operational defects in the form of crushing, wear and chipping of the metal of the edges develop directly during technological operations, as a result of which the required cutting quality is not ensured.

Therefore, the design flaw lies in its limited technological capabilities, which are reduced only to drilling and threading, and then without guarantees of high quality work.

Closest to the proposed technical solution is the design of a combined axial tool for machining holes (RU No. 138776, B23G 5/20, 03/20/2014), consisting of both a shank and a working part containing a drill with three cutting edges and three straight chip grooves, and also a tapping tap made integrally with each other. In this design, the stresses in the cutting edges are less than in the analogue design, since the load is distributed not on two, but on three cutting edges, and the lower end of the drill is made in a shape close to the tip, which does not work on squeezing the metal, but on penetration deep into it. Due to this, the intensity of chipping and crushing of the metal during the drilling process is minimized and the disadvantage of the analogue regarding the low quality of operations is typical of the prototype to a much lesser extent than the analogue.

The disadvantage of the design of the prototype is that its functionality is reduced to performing only two technological operations: drilling holes and threading them.

When developing a utility model, the problem was solved of expanding the capabilities of the combined axial tool by including an additional operation that will allow making holes for countersunk bolts simultaneously with drilling and threading in one pass without changing the tool.

The technical result is ensured by the fact that in the combined axial tool for machining holes, consisting of a shank and a working part, containing a drill with three cutting edges and three straight chip grooves, as well as a tapping thread made in one piece with each other, working the part on the shank side is equipped with a cylindrical countersink for making recesses for countersunk head bolts.

The essence of the technical solution is explained using the drawings, which show:

FIG. 1 - General view of the proposed design;

FIG. 2 - the lower end of the drill;

FIG. 3 - hole drilling operation;

FIG. 4 - operation of threading the walls of the hole;

FIG. 5 - the operation of the deepening on the surface of the part under the countersunk head of the bolt.

The combined axial tool for processing holes consists of a shank 1 and a working part 2, containing a drill 3 and a tapping 4 for threading, made in one piece with each other. The drill has three cutting edges 5. Its working part 2 from the side of the shank 1 is equipped with a cylindrical countersink 6 for developing recesses when drilling holes for a bolt with countersunk head (not shown in Fig.).

The device operates as follows. To connect parts 7 and 8, the drill 3 is gradually immersed in the material, first, part 7 (Fig. 3), and then parts 8 (Fig. 4). In the wake of it, the tap 4 is turned on. It puts the thread, and the core drill 6, having reached the surface of the part 7, performs a recess in it under the head of the bolt (Fig. 5). The whole process occurs through the continuous rotation of the drill around its axis 9 without the need for time to change the tool. Only the rotational speed can change, n revolutions per minute. depending on the magnitude of the reactive moment, which does not have the same resistance to the rotation of the drill 3 at various stages of hole development.

Claims (1)

Combined axial tool for machining holes, consisting of a shank and a working part containing a drill with three cutting edges and three straight chip grooves and a tapping tap, made in one piece with each other, characterized in that the working part from the shank is made in in the form of a cylindrical countersink for making recesses for bolts with countersunk heads.

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