RU2258854C1 - Method and device for machining teeth of cylindrical round-tooth gearings - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: according to the method proposed, the working cone of cutting edges of the initial profile embraces outer teeth of the blank or is embraced by its inner teeth. The device is made of the assembly of two tool racks with working members made of face conical cutting mills having different grinding of cutting edges.

EFFECT: improved quality of machining.

2 cl, 3 dwg

Description

The invention relates to mechanical engineering, namely to the production of gears, in particular cylindrical, used in the mechanisms of machines and devices as gears, multipliers and open gears.

A known method (method and device) for machining involute teeth of cylindrical gears of external gearing on gear cutting machines, called the method of running (bending) [1, p.6 ... 10], [2, p.232 ... 235], when the wheel blank in the process of coordinated movements is rolled around the tool rail with producing elements, and the teeth are formed on the workpiece by planing (chiselling) with the reciprocating movement of the rail along the tooth surface forming [1, p. 7 and 9 ... 10].

Instrument rail, as a device for implementing this method, has a base and fixedly connected with it producing elements with cutting edges that form profiles with the characteristic parameters of the standard initial contour (profile angle, module, etc.) [1, p. 8 ... 9].

The above known method and device have the disadvantage that they cannot be used to process the external and internal teeth of spur gears [3], since the formation of teeth of circular cross section requires not reciprocating movement of the producing elements, but rotational motion, which cannot be done when using a well-known tool rail.

In order to eliminate this drawback and use the break-in method for the production of gear wheels on a gear cutting machine, a method for forming external and internal teeth of circular cross-section by rotating the cutting edges of the profiles of the initial contour of the tool rail around the axis of symmetry of the profiles forming a producing cone covering the external teeth or covered by the internal teeth of the workpieces that perform the rolling movement relative to the rail, and in the first tea workpiece mounted beneath the rack, and the second - over it for a smooth removal of the work area of cut products. For the same purpose, as a device for implementing the above method, a set of 2 tool rails is claimed, the producing elements of which are made as end conical mills with the possibility of rotation (from the drive of the gear cutting machine) relative to the base of the rails, and milling cutters for processing external teeth are made hollow with internal cutting edges facing the axis of rotation, and milling cutters for machining internal teeth have external cutting edges facing away from the axis of rotation. The axes of the milling cutters are located on the base of the rails in one middle plane and in the section with this plane, the milling cutters have a profile of cutting edges that coincides with the profile of the standard initial contour (parameters: profile angle, module, tooth thickness, etc.).

An important technological advantage of wheels with round (especially external teeth over wheels with prismatic teeth (spur, helical) is the ability to produce workpieces with teeth (or finished gears) in symmetrically split molds by casting, pressing, forging, stamping, which dramatically reduces the volume cutting and chip output during subsequent machining The proposed tool rail for processing external teeth is most effective when machining a toothed billet with round teeth, square dratnogo or polyhedral cross-section, formed with the respective margins. Rail for processing internal teeth is equally effective when cutting teeth on the disc like workpiece, and the toothed.

The proposed method and device is illustrated by drawings.

Figure 1 shows the device in the context in cooperation with the gear billet - when processing external teeth.

Figure 2 is a bottom view of figure 1 with the designation of the middle plane.

Figure 3 shows the device in the context in cooperation with the gear billet when processing internal teeth.

Figure 1 shows the device (rail with base 1 and end mills 2) in cooperation with the gear billet 3 gears in section. Phases a, b, c, d indicate the sequence of processing of the external teeth 4 of the workpiece during the running-in process. The cutters 2 are mounted on the base 1 with the possibility of forced rotation from the drive of the gear cutting machine, for example, through a gear 5, shown conditionally. The cutting edges 6 of the producing cones of the cutters 2 are turned to their axes of rotation 7 and go to the ends 8 of the cutters.

Figure 2 shows the rail, including the base 1 of the cutter 2 (bottom view in figure 1) and the "middle plane" of the rail is indicated. Cutting edges 3 producing cones of mills are shown conditionally. The gap δ should be minimal, only excluding the contact of the cutters.

Figure 3 shows the base of the rack 1 with cutters 2 in cooperation with the workpiece 3 in a section along the middle plane of the gear rim of the wheel and the phases a, b, c, d of the sequence of formation of internal teeth 4 during the running-in are indicated. Milling cutters 2 have external producing cones, the cutting edges 5 of which are turned from the axis of rotation of the milling cutters and go to their ends 6 for processing cavities between the teeth.

The proposed method is carried out as follows: during the running-in movements (indicated by arrows in the figures) (Fig. 1), the external teeth 4 of the workpiece 3 enter the interior of the producing cone of the cutter 2 and come into contact with the cutting edges 6. When processing the internal teeth 4 (Fig. .3) on the disk billet 3, the billet comes into contact with the cutting edges 9 of the outer producing cone in the process of running-in with its periphery or the surface of previously made holes (for example, radially drilled).

In this case, the parameters of the cutter section 2 along the cutting edges 6 and 9 in the middle plane coincide with the profile parameters of the standard initial contour, due to which the teeth of the involute profile are formed.

The drive of milling cutters can be carried out both from machine tools and by an autonomous drive mounted on a table for installing a rail or on its base.

Literature

1. L.I. Aleksandrov et al. Gears. Publishing House of Kharkov State University, Kharkov, 1964, 275 p.

2. S. N. Kozhevnikov. Theory of Mechanisms and Machines, ed. "Engineering", M., 1973, 591 p.

3. Patent for invention No. 2199046 "Spur gear". Moscow, 02.20.2003.

Claims (2)

1. The method of processing the teeth of cylindrical gears of involute gearing by rolling the workpiece along a tool rail with manufacturing elements, the cutting edges of which pairwise form symmetrical profiles of the standard initial contour, characterized in that the teeth of circular cross section are formed by rotating the cutting edges around the axis of symmetry of the profiles so that they form producing elements in the shape of a cone, and these elements cover the outer teeth of the workpiece, while the workpiece is located under with a tool rail, or they are covered by the internal teeth of the workpiece, then the workpiece is located above the rail. 2. The device for implementing the method according to claim 1, containing two tool rails for cutting external and internal teeth, which have a base and producing elements with cutting edges, characterized in that these elements are made as end conical mills mounted on the base in one plane with minimal gaps between them with the possibility of rotation, and the parameters of the cutters on the cutting edges in this plane coincide with the profile parameters of the standard initial contour, and on the milling cutters for processing external the teeth of the workpiece, the cutting edges are facing the axis of rotation of the cutter, and on the milling cutters for machining the internal teeth, the cutting edges are facing away from the axis of rotation.

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