RU2095182C1 - Method and tool for knurling toothed wheels in metal-working machine - Google Patents

Abstract

FIELD: plastic working of metals. SUBSTANCE: method involves feeding radial knurling head in tangential direction till roller axes and billet axis are positioned in common plane; providing tooth knurling and gaging for one revolution of rollers. Cylindrical billet has one or two projections on its side surface. Knurling tool is made in the form of roller with working surface having charging-discharge, dividing, forming and gaging portions. Dividing portion has teeth of equal height with sharpened apexes. Forming portion is composed of several forming sections with equal-height teeth. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. 5 cl, 3 dwg

Description

 The invention relates to machine tool industry, in particular to methods and tools for rolling teeth on bodies of revolution on metal cutting machines of general technological purpose, for example, a turning group.

 Known radial thread rolling head company "FETTE" [1,2] for rolling external cylindrical threads. The knurling head contains two parallel-mounted rollers with a screw thread and mechanisms for synchronizing the rotation of the rollers with a drive, adjusting the diameter of the thread being rolled and a single-turn mechanism.

 The idea of using a “FETTE” type radial thread rolling head for gear rolling is also known [3] Rolling rollers during processing of a workpiece make one complete revolution, therefore, groups of dividing, forming and calibrating teeth are sequentially located on the periphery of the roller crown. In addition, on the surface of the rollers made loading sections in the form of flats, allowing you to freely bring the tool and take it relative to the workpiece.

 Also known are rolls [4] for rolling gears on specialized machines, equipped with a gear ring divided into sections, the teeth of which have a pitch circle diameter and pitch different from neighboring sections.

 The aim of the invention is to increase productivity, reduce material consumption and ensure stable shaping of a given number of teeth on the workpiece.

 The goal is achieved by combining two factors: the special design of the rolling rollers and the special shape of the workpiece.

 The method is illustrated in FIG. 1, 2 and 3.

где Z_к число зубьев обрабатываемого колеса.The roller (Fig. 1) has a dividing group of teeth 1 located in front of the deforming group 2, with equally high teeth for marking the workpiece for a given number of teeth by the number

where Z is _the number of teeth of the machined wheel.

The tops of the teeth of the dividing group can be pointed at a certain angle to reduce slippage between the rollers and the workpiece during operation (Fig. 1). The diameter of the vertices of the pitch teeth is equal to the pitch diameter of the roller
d _{a affairs} d _p
where d _{p is the} pitch diameter of the roller.

 The deforming part consists of several forming sections 2a, 2b, the teeth of which can be equally high or have a spiral rise. The roller also has a calibrating 3, output 4 and loading and unloading 5 sections.

The workpiece has the following form: the diameter of the workpiece d _z is equal to the diameter determined from the well-known condition for the equality of the cross-sectional area of the gear profile before and after deformation [4] and there are protruding belts on the side of the ends with a larger diameter than that calculated. The diameter of the protrusions is determined depending on the slip coefficient
d _to d _s / K _ol
where d _{is the} diameter of the workpiece, determined from the condition of equality of the cross-sectional area of the gear profile before and after deformation and approximately equal to the dividing diameter of the rolling wheel;
K _ave slip factor of 0,94-0,97 and dependent on the workpiece material, the presence of the coolant, the surface quality of the workpiece zubonakatyvaniya speed.

The workpiece may also have another shape: the protruding belt is located in the middle of the workpiece and has a diameter d _in , determined in the same way as in the previous case, and on the side of the ends the workpiece has a diameter (Fig. 3b).

It is known that when rolling gears, the resulting product, as a rule, has an irregular shape: the height of the teeth at the ends is less than the height of the teeth in the middle of the gear rim (h _t <h _in , figv). To eliminate this, it is necessary that the area of the protruding girdle (S _ABC , figa, b) in the section perpendicular to the axis of the workpiece is greater than or equal to the area in the section perpendicular to the axis of the wheel, bounded by a tangent drawn to the top of the tooth parallel to the axis of the wheel, by a line the intersection of a plane perpendicular to the axis of the wheel with one of its end surfaces and a section of a curved generatrix of the tooth in section with its plane perpendicular to the end surface of the wheel and its axis (S _{A'B'C '} ).

 The method is implemented as follows.

 The knurling head, mounted, for example, in the tool holder of the lathe, is fed in the tangential direction until the axes of the rollers coincide with the axis rotating in the workpiece spindle in the same plane. Under the action of the drive of the synchronization mechanism, the rollers begin to rotate and the teeth of the dividing part under the action of friction with a rotating workpiece squeeze the depressions in the protruding belts of the workpiece, marking thus a predetermined number of teeth. The teeth of the deforming part of the roller, falling into the hollows made by dividing teeth, carry out a full position.

Claims (5)

1. The method of rolling gears on metal cutting machines for general technological purposes, namely, that the radial knurling head is fed in a tangential direction until the axes of the rollers and the axis of the workpiece are in the same plane, after which the teeth are rolled and rotated during one revolution of the rollers calibration, characterized in that a cylindrical workpiece with one or two protruding located on its side surface is used as a workpiece to obtain a gear belt, the diameter of which is selected from the ratio

where d _{is the} diameter of the belts, mm;
d _{h the} diameter of the workpiece, determined from the condition of equality of the cross-sectional area of the gear profile before and after deformation, mm,
To _pr slippage coefficient equal to 0.94 0.97, while the area of the protruding belt in the section perpendicular to the axis of the workpiece is greater than or equal to the area in the section perpendicular to the axis of the wheel bounded by a tangent drawn to the top of the tooth parallel to the axis of the wheel, the line of intersection of the plane perpendicular to the axis of the wheel, with one of its end surfaces and a section of a curved generatrix of the tooth in section with its plane perpendicular to the end surface of the wheel and its axis. 2. The tool for rolling gears on metal cutting machines, made in the form of a roller with a working surface containing loading and unloading, dividing, forming and calibrating sections, characterized in that the dividing section is made with equally high teeth number

where Z _{to the} number of teeth of the rolling wheel,
while the tops of the teeth are located on the diameter d _{a affairs.} d _p where d _{p the} dividing diameter of the roller.  3. The tool according to claim 2, characterized in that the tops of the teeth of the dividing part are made pointed.  4. The tool according to any one of paragraphs.2 and 3, characterized in that the forming portion of the working surface of the roller is made of several forming sections with equally high teeth.  5. The tool according to any one of paragraphs.2 and 3, characterized in that the forming portion of the working surface of the roller is made of several forming sections with teeth having a spiral rise.

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