RU2812923C1 - Method for manufacturing retaining split rings - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention can be used in the production of locking split rings. The coil spring is wound, after which both ends are ground. The spring is compressed until the coils touch and fixed in the compressed position. The spring is cut into individual turns by cutting a groove in it on an electroerosive wire cutting machine with an electrode wire having a diameter of 0.10 to 0.20 mm.

EFFECT: gap between the edges of the split ring is reduced.

1 cl, 2 dwg, 1 ex

Description

The invention relates to the production of split washers and rings for various purposes and can be used, in particular, in the manufacture of locking split rings from wire.

In mechanical engineering, split washers and rings of various designs and purposes are widely used. Common methods for their manufacture include winding a piece of wire or a rod of round or rectangular cross-section, cutting and straightening. Depending on the requirements, the technological process can be supplemented with heat treatment, protective coating, etc.

Hereinafter, the term “groove” will be used to name the gap between the ends of the wire in the finished ring, and the term “groove width” will be used to characterize the size of the gap.

Depending on the purpose and, accordingly, the requirements for split washers and rings, the width of the groove can be normatively limited and/or the angle of its inclination relative to the axis can be specified.

There is a known method for manufacturing Grover washers, carried out using a device by cutting off cylindrical screw turns (A.S. No. 64726, publ. 05/31/1945). According to a well-known solution, it is supposed to wind a single cylindrical coil and then cut it off with knives in a special device.

There is a known method for making rings from wire, carried out using a device for making rings from wire and including winding a coil spring into a section of turns using a built-in knife (pat. RU 2093293, publ. 10.20.1997). The number of turns of the wound spring in a known solution is determined by the length of the working part of the mandrel between the knife and the stand.

The general disadvantages of the known solutions include the inevitable formation of a burr in the cutting area and the individual separation of the turns. Removing a burr will require the introduction of additional operations into the technological process. Piece-by-piece separation (cutting) of coils with a large production program will lead to the need for frequent changes of knives.

The closest, in terms of the totality of essential features - the prototype of the claimed invention - is a method for manufacturing split washers, including winding a helical spring and its subsequent cutting into individual washers (coils, URL: http://pereosnastka.ru/articles/izgotovlenie-pruzhinnykh-shaib ( published June 22, 2019)). According to a well-known solution, cutting the helical spring into individual washers is performed using a cutter.

There are known rules for choosing slotting and cutting cutters based on the depth of milling. For a milling depth of up to 5 mm (the diameter of the wire for making retaining rings, as a rule, does not exceed ∅3 mm), according to existing rules (see, for example, the Machine Operator's Handbook: a textbook for beginning vocational education / L.I. Vereina, M.M. Krasnov - 2nd ed., revised - M: Publishing Center "Academy", 2008. - 560 pp. 409), the minimum cutter diameter is ∅50 mm, and the groove width is from 0.5 mm to 0.6 mm.

The disadvantages of the known solution adopted as a prototype include its limited use with split washers and rings, the technical requirements for which allow a groove width equal to or greater than 0.5 mm. If for standard rings, the requirements for which are regulated by OST 1 10241-71, OST 1 10242-71, OST 1 10243-71, DIN 7993, the known solution can be applied, then for special cases when it is necessary to minimize the width of the groove, ensuring the distance between edges no more than 0.25 mm, the known solution is not suitable. Reducing the width of the groove in the retaining rings is an urgent task, in particular, in the manufacture of high-pressure fuel lines for battery-type systems. According to the applicant's experience, one of the customer requirements for such systems is to reduce the groove width to 0.25 mm.

The technical objective of the present invention is to create a method for manufacturing locking split rings that provides a groove width of no more than 0.25 mm when cutting.

The technical result of implementing the proposed method is to reduce the gap between the edges of the split ring.

The solution to the stated technical problem is achieved by cutting the helical spring into individual washers on an electroerosive wire-cutting machine using an electrode wire with a diameter of 0.10 mm to 0.20 mm.

This feature is new, significant, industrially applicable and is aimed at achieving the stated technical result.

According to the applicant's experience, the use of an electrode wire with a diameter less than 0.10 mm is impractical. Such wire is used mainly to obtain small radii in the inner corners of the profile being cut, it requires more machine time, can break more easily, etc. For cutting a helical spring, the most suitable electrode wire is the specified size range. Even when using an electrode wire ∅0.20 mm, taking into account possible displacements of the tool relative to the part, the width of the resulting groove remains within the permissible size. Wire electrode ∅0.10 mm is the most common. According to (URL: http://engcrafts.com/item/1513-provoloka (date published 10/08/2018)), it is used in more than 80% of work on electrical discharge equipment.

The method of manufacturing retaining split rings proposed as the present invention includes the following technological operations:

- winding of a helical cylindrical spring from round wire; winding of said spring can be carried out by any known method;

- grinding both ends of the coiled spring;

- cutting a longitudinal groove on an electroerosive wire cutting machine.

Before cutting a longitudinal groove, it is preferable to compress the spring until the coils touch and fix it in this position. This allows you to reduce the length of the cut section and eliminate vibrations and displacements of individual rings after cutting them. Preliminary grinding of both ends of the wound spring makes it possible to simplify the device for compressing the spring until the coils touch and fixing it in this position.

An example of the proposed method.

In fig. Figure 1 shows a device specially made for cutting a groove on a spring and having a longitudinal slot for the passage of a tool wire.

In fig. Figure 2 shows the manufactured locking split rings after cutting the groove.

Retaining split rings were made from wire with a diameter of ∅2.8 mm. The width of the groove in the finished rings should have been no more than 0.25 mm.

Five helical coil springs were wound. Both ends of each spring were ground to a flat bearing surface.

The springs were installed one by one into the body 1 of the device shown in Fig. 1, was compressed until the turns touched and fixed in this position with screw 2.

After this, the device was installed on an electrical discharge wire cutting machine.

On three springs, a groove was cut with an electrode wire with a diameter of ∅0.10 mm, and on two springs - with an electrode wire with a diameter of ∅0.20 mm.

The locking split rings obtained after cutting the groove are shown in Fig. 2. The largest groove width was 0.22 mm.

The proposed method for manufacturing locking split rings is being prepared for introduction into mass production at the Altai Precision Products Plant.

Claims (1)

A method for manufacturing retaining split rings, including winding a helical spring and its subsequent cutting into separate turns, characterized in that after winding the spring, both ends are ground, the spring is compressed until the turns touch, fixed in a compressed position, the groove is cut on an electroerosive wire-cutting machine electrode wire having a diameter of 0.10 to 0.20 mm.