SU975269A1 - Tap - Google Patents

Description

(54) METER

one

This invention relates to the processing of materials, in particular threading.

Known cutting tap consisting of a shank and a working part, the sides of the chip grooves of which are made with oppositely directed equal angles 1.

The known tap has a number of significant flaws, the main of which are: adverse cutting conditions on one of the cutting edges of the teeth, since while on the one side of the tooth a positive cutting angle is formed, on the other side the cutting angle is negative, which leads to reduced tool life, and increased friction torque when tapping for the same reason, which can lead to pinching of the tap, with the result that the well-known tap is used as the last one in the Kit with other taps.

The purpose of the invention is to increase the operability and durability of the tool and to improve the quality of the cut thread.

This goal is achieved by the fact that in a tap with an even number of feathers, on which odd feathers have an under-profile on the right side and on even ones on the left side, the front surfaces of odd feathers are inclined to the axis of the tap at an angle greater than the helix angle of the thread. , and even - at an angle smaller than the angle of elevation of the helix thread.

FIG. 1 shows a development of the tap closure cone; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a section BB in FIG. one; in fig. 4 is a metal removal scheme for the teeth of the tap during thread reforming.

The tap has pens 1-4, and pens 1 and 3 are even, and pens 2 and 4 are odd.

15 The proposed tap works as follows.

When the screwing-in of the tap into the hole being machined, the teeth of the tap located on the intake cone step into the hole and remove the layer

° metal that side of the cutting edge of the profile, the leading angle of which is positive. The other side of the tooth profile does not come into contact with the thread profile formed and does not participate in the cutting process. The position of the cutting and undercut edges alternate between the teeth located along the helix. Then, the teeth of the gage part, which have a full profile and are used for the final formation of the profile and for the steady direction of the tap in the thread, come into operation. The proposed tap has the following advantages over the well-known one: threading takes place under optimal conditions with minimal and equal loads on the teeth, since the front corners of all the teeth of the intake part are positive and the same; there is no friction of the underestimated part of the back surface of the tooth, and the profile of the thread formed, which reduces the moment of friction

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Claims (1)

Jfi tap, prevents pinch pinching and improves thread quality. An inventive tap with an even number of feathers, on which the profile is lowered on the right side on odd feathers and on the left side on even ones, in order to improve the quality of the cut thread and tool durability, the front surfaces of the odd feathers are tilted at an angle greater than the elevation angle of the thread helix, and even even at an angle less than the angle of the thread helix. Sources of information taken into account during the examination 1. USSR author's certificate No. 281125, cl. In 23 G 5/06, 1969. Phie. / X- /} -Y / dd F1 / e.