RU1804379C - Tap - Google Patents

Abstract

Usage: a tap improves the quality of the thread cut into blind holes in difficult to process materials. SUMMARY OF THE INVENTION: The tap comprises an intake part 1 with teeth, the profile of which is underestimated on the sides, a calibrating part 2 and stitch grooves 4, made helical. The teeth on the calibrating part of the tap on the outer diameter are made unprepared. In addition, the tooth on the calibrating part in a checkerboard pattern is made with understating the profile of the sides. 4 ill.

Description

Figure 1

The invention relates to metalworking tools, namely tapping taps, and can be used in taper designs for tapping blind threads in difficult to process materials, for example, rotor shafts of powerful turbo-generators.

The aim of the invention is to improve the quality of the thread cut in blind holes of difficult to process materials, for example, in the rotor shafts of powerful turbo-generators made of chrome-nickel-molybdenum-vanadium steels.

This goal is achieved due to the fact that in the tap containing the intake part with teeth, the profile of which on the sides is made with underestimation, the calibrating part and chip grooves, the tooth on the calibrating part of the tap on the outer diameter is made not puffed and staggered a plate with an underestimation of the profile of the sides, while the chip grooves are made screw.

The novelty of the claimed solution consists in a new set of features, namely, in a new implementation and combination of structural elements of the working part of the tap. Instead of the known cutting of teeth in a checkerboard pattern or uneven knitting of all teeth of the cutting part, the depressions in the checkerboard are deepened along the thread along the entire length of the working part. By uniformly deepening the troughs, a simultaneous narrowing of two tooth profiles facing one another is achieved. The depressions are deepened with the same tool and on the same equipment as the grinding of the working profile of the tap thread. This simplifies the technology. the labor of manufacturing a tap is reduced, and the quality of the thread being cut is improved.

By narrowing the teeth, gaps are formed between the side walls of the profile of the narrowed teeth and the corresponding walls of the profile of the thread being cut. This solution reduces the torque in the operation of the tap.

Instead of backing the teeth along the middle and inner diameters along the entire length of the working part, backing with a value of K was performed only along the outer diameter and only along the length of the cutting part. The backing of the tap only by the outer diameter of the cutting part of a constant value in comparison with the known backing by the average and internal diameters of the cutting and calibrating parts, in addition, the technology simplifies various sizes,

reduces labor costs for the manufacture of a tag.

The absence of backfill on the calibrating part of the tap ensures smoothing of the threads, reduces breaking of the thread being cut and, when turning the tap out of the hole, it prevents wedging by the chip particles in the hole.

The values of known structural elements established experimentally: an increase in the number of feathers to z 5, the angle of inclination of the helical grooves and 28 ° in combination with

the proposed deepening of the profile of the depressions, the backing of only the outer diameter and only the cutting part provide high-quality cutting of large metric threads with large pitch in blind deep holes of difficult to process materials with a single tap, i.e. in one pass of the tool. An increase in the number of feathers increases the number of cutting teeth with a short length of the cutting part and provides a reduction

the thickness of the cut for one tooth when cutting the total allowance, and the increase in torque is compensated by the presence of lateral gaps on the side walls of the tap thread profile. In addition, an increase in the number

feathers contributes to a better direction of the tap along the axis of the hole.

The set value of the inclination of the helical grooves (uJ 28 °) in combination with other proposed structural

elements ensures continuous and complete removal of chips from the blind hole on the surface of the product, which excludes grinding and falling under the tooth when the tap is removed from the hole.

The claimed solution achieves a simplification of manufacturing technology and an increase in tap performance when cutting large metric threads with large pitch in blind holes of products from difficult to process materials, for example, in the rotor shafts of powerful turbo-generators made of chromonickel-molybdenum-vanadium dtal.

All this provides a super-cumulative effect and allows us to state the significance of the differences of the claimed technical solution. In FIG. 1 shows a tap, a general view; figure 2 - pen working part with a deep

stitching in a checkerboard pattern; in Fig.3 - section aa in Fig.1; Fig. 4 is a diagram of cutting metal layers.

The tap consists of a cutting part 1 (see figure 1) at a length h, calibrating part 2 on

length I-H and shank 3. angle of inclination of the chip grooves 4 to the axis, the number of which, for example, z.- 5, and (28 ° (experimentally determined as optimal), d is the diameter that limits the active height of the thread profile of the tap.

The recessed depressions 5 are staggered along the thread along the entire length of the working part (see Fig. 2), p is the angle of inclination of the generatrix of the intake cone.

The magnitude of the recess t, measured perpendicular to the axis of the tap, is determined by the formula

+ O055P t - 2,

where P is the thread pitch, mm, and the one-sided gap azi between the side walls of the tooth profile is determined by the formula azi t sin

where "is the half angle of the thread profile, deg.

In Fig. 3, the following designations are adopted: dHap is the outer diameter of the calibrating part 2, dcp is the average diameter of the teeth of the calibrating part, dBH is the inner diameter of the teeth of the calibrating part, K is the backfill amount over the width of the pen.

The tap works as follows. When entering the hole, the tap is centered and rests on the walls of the hole with the feather cone with an angle of 2 p. The teeth of the intake cone (cutting part at a length li) are cut out by layers of metal according to the scheme shown in Fig. 4. To every cutting tooth

5

a thick layer of a metal of az is cut off. defined by the formula

h n h l L

 YTR-9 z- where h is the height of the cut profile (total allowance in mm);

N is the number of incisors on the cutting part; n is the number of turns on the cutting part; Z is the number of feathers of the tap. 0 Between the side walls of the profile through the tooth in a checkerboard pattern, a gap of azi is formed over the entire length of the working part, which reduces torsional loads on the tap, eliminates the sticking of 5 teeth on the walls and improves the performance of the tap ..

The feasibility of the claimed solution is to simplify the manufacturing technology of the tap, 0 to increase its productivity and the quality of the cut thread.

Claims (1)

SUMMARY OF THE INVENTION A taphole containing a suction part with teeth, the profile of which on the sides is underestimated, the calibrating part and the chip grooves, on the side and so that, in order to improve the quality of the thread cut into blind holes x, the tooth on the calibrating part / tap along the outer diameter is made uncut and staggered with an underestimation of the profile of the sides, while the chip grooves are made screw. 5 0 Editor M. Kuznetsova Compiled by I. FeDorenko Tehred M. Morgenthal Corrector Y. Papp