SU1252081A1 - Apparatus for broaching openings - Google Patents

Description

The invention relates to metal working, in particular, to the pulling of holes in workpieces having a pre-machined hole, and may be used when drawing or backing holes on various machine tools.

The purpose of the invention is to improve the processing accuracy by rigidly fixing the distance.

FIG. Figure 1 shows a device for pulling holes before starting to draw; in fig. 2 shows section A-A in FIG. 1 (with the implementation of a double ring centering mechanism); in fig. 3 is the same when the single-centering mechanism is performed.

The device for pulling holes includes a cartridge 1 for fastening the broach and the broach 2. The forward direction of the knuckle part 3 of the broach 2 for rigid fixation with the axis of the previously machined hole of the installed workpiece 4 is provided with a centering mechanism made in the form of a double 5 or single ring 6 with radial conical holes 7, in each of which a ball 8 or roller 9 is installed, and two sleeves 10 installed one after the other in a series with the possibility of axial movement relative to the pro buckle 2 and reacting with the cartridge 1 through the glass 11. In this case, decompression is performed balls 8 and rollers 9 centering pulldown or 2: rigid fixing it relative to the axis of the pretreated preform aperture 4 before pulling. The release of the balls 8 or the rollers 9 occurs due to the implementation of the sleeves 10 with tapered end surfaces.

One of the sleeves 10, which directly interacts with the cup 11, has limited axial movement relative to the broach due to the use of a pin 12 and a longitudinal groove 13 in the sleeve. The double ring 5 in the centering mechanism with the mounted balls 8 can most effectively be used for drawing openings of workpieces in which the pre-processed hole has an upper hole.

This is due to the use of the second sleeve 10, which is installed between two rows of balls, to eliminate 5 s distortions and to provide the necessary centering of the length with its rigid fixation relative to the axis of the pre-machined hole of the workpiece 4 before starting

10 inches.

When pulling the balls, they easily overcome possible tapering or punching slopes in a pre-machined hole, leading to these inaccuracies.

A centering mechanism, made in the form of a single ring 6, sleeve 10 and rollers 9, can be used to pull holes

20 workpieces in which the pre-machined hole has a minimum taper, since due to the use of rollers made with ends rounded along

25 sphere, and with a lower diameter in the middle part, all possible errors of the pre-machined hole are compensated and the necessary centering is provided

30 stretching with rigid fixation of it with respect to the axis of the pre-machined hole of the installed workpiece before starting to be drawn.

When pulled, rollers 9 make it possible to easily overcome the possible minimal inaccuracy of the pre-machined hole, the specified surface.

To increase the operational reliability of the proposed device, the hardness of heat treatment of balls or rollers, the tapered parts of the sleeves, and the rings of the centering mechanism should be chosen slightly lower than the hardness of the draw.

The device for pulling holes works as follows.

When compressed air or pressure oil is supplied to the cartridge 1, the cup 11 is moved, as a result of which fixing of the draw-2 occurs. Upon further movement of the cup 11, the latter, interacting with the sleeves 10, releases the balls 8 or the rollers 9 with the centering of the broach 2 and rigidly fixing it with respect to the axis of the pre-machined hole of the workpiece 4

40

50

before the start of pulling, then from the time relay, the working stroke of the pulling starts, continuing until the end of pulling the hole with the termination of the pulling cycle from the end switch.

The use of the proposed device allows the execution of holes through the holes without an increase in the accuracy class of the previously machined holes and freely allows the holes to be pulled without prior

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trimming the ends in the workpieces, because by ensuring the centering of the draw and its rigid fixation with respect to the axis of the pre-machined hole of the installed workpiece, before beginning to pull, the effect is given, which allows any torsion of the workpiece to be compensated using a self-aligning ball bearing fixed to the faceplate of an extension machine.

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Editor I. Shulla

Compiled by I. Likhopoy Tehred N. Bonkalo

Order 4568/14

Circulation 1001 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Fig.Z

Proofreader T. Kolb

Claims (1)

DEVICE FOR Pulling openings, including a cartridge for attaching a broach and a broach with a cutting part, front and rear guides, characterized in that, in order to increase the accuracy of processing, the device is equipped with a centering mechanism arranged on the front guide made in the form of rings with radial conical holes, balls installed in them, and bushings with end conical surfaces mounted with the possibility of axial movement and interaction with the balls. Figure 1