SU808224A1 - Threading die - Google Patents

Description

(54) DICE

I

This invention relates to metal formation, namely cutting external threads with dies.

A die is known, which is a hollow cylinder, on the surface of the hole. which made the threaded section, divided into feathers with cutting edges having a rake angle on the cutting part larger than the calibrating l.

The disadvantage of a die is the difficulty of its manufacture and sharpening. In order to press the die's feather on the cutting part, a separate operation is required, during which the cutting part of each of the feathers of the die is machined with a tapered countersink with an angle of 20 set at an angle of 15 ° to the axis of the die. On the cutting edge of such dies, at the junction of the cutting part (made as a line of intersection of a cylindrical and conical surface) and calibrating part (made; as a line of intersection of two cylinders with parallel axes), a transition section is created on which stress concentrates occur, reducing the resistance of the die .

The purpose of the invention is to simplify the technology of manufacturing dies.

This goal is achieved by the fact that an annular threaded protrusion is made on the surface of the die hole, and in its walls there are conical holes, the smaller base of which crosses the protrusion, forming a feather with cutting edges.

FIG. 1 shows a die, general view, in FIG. 2, view A in FIG. I.

Claims (1)

Plate I has the shape of a short hollow zingfing on the surface of the hole 2 is made of an annular threaded protrusion 3. In the walls 4 of the die there are conical holes 5 that intersect the threaded protrusion 3 and divide it into cutting pens. At the intersection of the conical hole 5 with the thread of the protrusion, cutting edges are formed, the leading angle of which on the cutting part is larger than the front angle f on the calibrating part of the pen. In this case, the rake angle gradually decreases from the periphery of the thread to the thickness of the die, and the amount of the front angles T ft depends on the number and diameter of the holes 5, as well as on the angle "1 of the tool cone that makes the hole 5, on the angle fi between the hole axis S and a raius of the plate and on the angle d between the plane.y which lies the axis of the hole 5, and the axis of the plate. .When a thread is inserted into the die, a large rake angle on the cutting part of the die provides favorable cutting conditions, and a small rake angle on the calibrating part ensures clean and smooth, without tearing, the thread, especially on viscous materials. The gradual reduction of the rake angle to the middle of the die thickness, ie, the concentration of stresses in certain parts of the cutting edges and provides a high-quality thread calibration. The presence of conical holes, swept from the outer cylindrical surface of the dies and forming cutting edges at the intersection with the thread, will make it easier to manufacture dies with variable rake angle. 8 44 pen. When an atom is provided, it is possible to produce single-handed production of all cutting edges on a multi-spindle machine, as well as their simultaneous sharpening. The presence of these holes provides also the possibility of applying wear-resistant coatings on the front face of the die's feathers. The invention of the plate is a hollow cylinder, on the surface of the aperture of which a threaded section is made, divided into feathers with cutting edges / 1kah, having a rake angle on the cutting part larger than the calibrating one, characterized in that on the surface of the die hole there is an annular threaded protrusion, and in its walls are conical holes, the smaller base of which crosses the protrusion, forming a feather with cutting edges. Sources of information that are taken into account during the examination 1. I. Semenchenko. and others. Design of metal-cutting tools. M. Mashgiz, 1963, p. 573, FIG. 327. L Type A Fi9.