SU979030A1 - Apparatus for cutting thread - Google Patents

Description

(54) DEVICE FOR THREAD CUTTING

one

The device relates to mechanical engineering and can be used in factories producing parts for a round-hole drilling tool.

A threading device containing a hollow spindle spindle head with cutter 1 located inside is known.

When cutting a thread with a pass-through method using a known device, a groove is cut through the part to be cut to exit the tool at the end of the cut, and when turning with a turning method (where the groove is not required), the thread cut is cut, which is also a stress concentrator. During the operation of such parts often breakage of the latter along the grooved groove. All this is a disadvantage of the prior art.

The aim of the invention is to exclude voltage concentrators in the form of a groove for the tool to exit.

To achieve this goal, the device is provided with a slider installed in the spindle with the possibility of radial movement, in which the cutter is fixed and executed a conical hole, and a sleeve with a wedge protrusion installed in the spindle with the possibility of moving and interacting with a wedge projection with the conical walls of the slider hole and at an angle determined by the depth of the profile and the pitch of the thread being cut.

Fig, 1 shows the proposed device, a longitudinal section; in fig. 2 view A in FIG. one; in fig. 3 is a view B in FIG. 1.

The device comprises a base 1, with which it fastens a support for a lathe. Based

the spindle head 2 and the electric motor are placed (not shown inside the hollow spindle 3 installed in the head housing on rolling bearings, a sleeve 4 is widened, the wedge 5 of which fits into the conical hole of the slider 6 which is placed in the radial guide spindles 3. B A thread-cutting tool 7 is fastened to the slider. At the opposite end of the protrusion 5 of the sleeve 4, a collar 10 is installed with the clip 8 and rolling bearing 9, the lower part of which is fixed to the base of the head body using the I axis and the upper m It can slide along the rod 12, fixed on the lathe motionlessly on the lathe. Adjustable stops 13 and 14 are fixed to the rods 12. A spring 15 is placed in the blind hole.

The device works as follows.

The rotation from the electric motor is transmitted through a V-belt transmission to the hollow spindle 3. Together with the spindle, the sleeve 4 is rotated and the slider 6 is cut with the cutter 7. When threading, in addition to the spindle and the workpiece rotations, the spindle and the axial movement At the end of the cutting, the upper part of the collar 10 abuts against the adjustable stop 13 and, turning around axis 11, pulls the sleeve 4 out of center 3, releasing the slider 6 with the help of a wedge protrusion 5 in the radial guides of the spindle under the action of the spring 15, rejects the tip of the cutter 7 from the screw groove of the thread being cut to the surface of the workpiece. During the return stroke of the machine caliper, using the stop 14 and the clamp 10, the sleeve 4 and the slider 6 return to their original position. projection oL

The design is designed so that the full exit of the helical groove to the surface of the workpiece is carried out at the size of one pitch of the cut thread.

For example, when cutting threads with a round profile on drill rods with a diameter of 32 mm, with a thread pitch of 12 mm and a profile depth of 2.0 mm, the bevel angle

06 spike is determined from the ratio

; -tofo - | -, / fe6; ayu °,

where ti is the depth of the profile;

S - cut pitch. The use of the proposed device ensures, due to the smooth outward rezd of the screw groove of the workpiece, threading without stress concentrators, which allows durability, for example, drill rods by 20-30%.

Claims (1)

1. Viksman, Ye.S., High-Speed Threading and Worm Covers. M., Mechanical Engineering, 1966, p. 32 (prototype).