RU1808547C - Tap - Google Patents

Abstract

Use: tap designed for threading in viscous materials. 2 Summary of the invention; on the tap intake part 9, the channel for chip evacuation is made in the form of a series of holes 17 with a 0.5 thread pitch in the depressions and at the tops of the threaded surface. On the calibrating part of the tap, this channel is made in the form of longitudinal grooves 6. The central channel of the tap is tapered. The tap shank is hollow and mounted on the intake side 9. 5 il.

Description

The invention relates to metal cutting tools, in particular taps for cutting cylindrical threads.

The purpose of the invention is to improve the quality of cut threads made in viscous materials.

This goal is achieved by the fact that on the intake part of the tap the channel for chip removal is made in the form of a series of holes with a diameter of 0.5 thread pitch located in the hollows and on the tops of the threaded surface, and on the calibrating part of the tap the channel for chip removal is made in a row of longitudinal grooves, while the Central channel is made conical with an angle of inclination of the generatrix in the direction of the shank, made hollow and installed from the intake side.

The invention is illustrated by drawings, in which Fig. 1 shows a general view of a tap; Fig. 2 is a section AA in Fig. 1; in Fig.Z is a longitudinal section of a tap; figure 4 - shows the position of the tap when screwing into the preliminary hole; figure 5 is a section bB of figure 2 along the intake part.

The following designations are introduced: shank 1, cavity 2, channel for chip evacuation 3, turns 4, tap axis 5, longitudinal grooves 6, tops 7, troughs 8, intake part 9, calibrating part 10, body 11, workpiece 12, axes 13, threaded surface 14, shavings 15 forming 16, hole 17, central channel 18, edges 19,20, extruded portion of thread A, final formed portion of thread B, thread calibration portion B, pitch t, offset L angle a. angle of inclination /, diameter d.

These elements are interconnected as follows. The tap consists of a housing 11 and a shank 1, contains a channel for removing chips 3, made on the intake 9 and calibrating 10 parts and communicating with the central channel 18 made in the housing 11. On the intake part 9, the channel for removing chips 3 is made in the form of a row holes 17. located in

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in the depressions 8 and on the peaks 7 of the threaded surface 14 of the turns 4, with a diameter d equal to 0.5 of the thread pitch t On the calibrating part 10, the channel for chip removal 3 is made in the form of a series of longitudinal grooves 6, while the central channel 18 is conical with an angle of inclination / generatrix 16 to the axis of the tap 5 in the direction of the shank 1, made hollow with a cavity 2 and installed on the side of the intake part 9. The axis 13 of the holes 17 are made with an offset D, providing a smooth transition from the holes 17 to the central channel 18, and inclined to the axis of the tap 5 at an angle a. Chip 15 is removed from preform 12. Hole 17c with threaded surface 14 forms edges 19.

The tap is a combined cutting strain. During operation, the deformation is carried out by turns 4, which, pressed into the workpiece 12, deform the metal plastically and elastically, causing it to undergo all-round compression. As a result, on the extrusion section of thread A, its profile is formed, while partially the metal finds an outlet at 1 hole 17, flows in them, resiliently restores and is cut off by the edges 19. In the section of the final formation of thread B, all excess metal goes into the hole 17. Formed the chips 15 from the holes 17 fall into the central channel 18. At the thread calibration section B, due to the longitudinal grooves 6, the calibration part 10 is elastically deformed by the elastic unloading metal of the workpiece 12 being worked as a collet, it carries out a final cutting working pass with the edges 20 of the hardened metal with a constant pressure exerting pressure on it, improving the quality of the thread. In this case, the cutting with the edges 20 is carried out in a slightly different direction than this occurs in sections A and B with the edges 19, ordering structure of the formed surface of the thread. The preliminary hardening of the viscous material of the workpiece 12 during comprehensive compression eliminates its sticking to the tap and baling, and ensures calibration of normal cutting and high quality threads. The conical shape of the central channel 18 facilitates the removal of chips from the tap, through the cavity 2 in the shank 1 it is supplied with coolant pressure, improving the chip, through it mechanical

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tap tap, for example using a push rod. The offset D of the axes 13 provides an increase in the rake angle and therefore must be in the direction opposite to the direction of rotation of the tap during cutting. The angle a on the slope of the axes 13 to the axis of the tap 5 provides the movement of the chips 15 to the calibrating part 10. The holes 17 should overlap the entire perimeter of the turns 4, therefore, they are made along the tops 7 and depressions 8 and have a diameter d equal to 0.5 thread pitch t. An increase in the diameter d in comparison with the indicated value will improve the cutting conditions and chip evacuation, but will decrease the strength of the tap and may interfere with the formation of a full profile thread. A reduction in diameter d is unacceptable due to an increase in torque and the likelihood of a tap breakage. The location of the shank 1 on the side of the intake part 9 allows to reduce the oscillations of the tap and to improve the accuracy and cleanliness of the threaded surface 14.

Thus, due to internal chip removal, preliminary hardening of the metal before cutting, increasing the rigidity of the tap, and the elastically deformable design of the calibrating part, the quality of the cut thread in viscous materials is improved.

For example, such taps make it possible to obtain threads in zinc alloys and with high quality, which is not possible with cutting taps of a standard design.

Formula of the invention

A tap comprising a housing with a shank, a chip discharge channel made on the intake and calibrating parts of the tap and communicating with a central channel formed in the housing, characterized in that, in order to improve the quality of the thread cut into viscous materials on the tap intake the chip evacuation channel is made in the form of a series of holes with a diameter of 0.5 thread pitch located in the hollows and on the peaks of the threaded surface, and on the calibrating part of the tap, the evacuation channel is made in the form of a series of longitudinal grooves, at m central channel is conical with an angle of inclination of the generatrix in the direction of the shank, constructed hollow and installed by the suction portion.

No.8081

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