RU2347792C1 - Composite material solution for cushion blocks of rail braces - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention pertains to rubber industry, particularly to composite material based on rubber mixtures, containing methylstyrene and divinyl rubber, and can be used for making sluper and rail pad shock-absorbers of railway tracks. Compound contains the following components, wt %: crushed rubber coated polyamide cord with fibre length 10-15 mm-17.0-18.5, rubber compound based on methylstyrene and divinyl rubber, containing a vulcanising group and inactive technical carbon - 77-78, particulate filler material-granulated sphate spew from the stage of vulcanisation of the shock-absorber pads-2, granulated rubber crumbs - 2.0-3.5.

EFFECT: increase in the resources of working capacity of the cushion bolsters, friction coefficient on the steel per-unit-volume of resistance of the electric current.

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Description

The invention relates to the rubber industry, in particular to composite materials based on rubber compounds containing methyl styrene and divinyl rubbers, and can be used for the manufacture of on-rail and rail-mounted shock absorbers for railway shock absorbers.

Currently, gaskets for rail shock absorbers are subject to increased requirements for operational indicators, in particular, for the service life and specific volume resistance to electric current.

Known rubber compound for on-head gaskets of increased durability according to patent SU No. 1692993 (filing date of the application on 12/26/1988). This mixture makes it possible to obtain gaskets - shock absorbers with indicators of a working life of 1000 million tons and specific volume resistance to electric current of 10 ¹⁰ Ohm · cm.

Known depreciation pad containing a polymer composite element having in its composition particles of dispersed fillers and fiber reinforcing cord filler, which are pre-stretched and in such a stressed state are fixed with a polymer binder (Patent for PM No. 49008, filing date 04/19/2005). The fibers of this reinforcing cord filler have the dimensions of a shock absorber pad. Gaskets obtained with this polymer composite material have insufficient operational characteristics (Operating time - 1100 million tons; Specific volume resistance - 10 ^10. Steel friction coefficient - 0.5 (sliding friction between the rail sole and the shock absorber pad), as well as complex preparation method.

The closest to the claimed invention according to its purpose and composition is a rubber mixture for the manufacture of rail-mounted and on-rail gaskets-shock absorbers for rail fasteners, including a base made of styrene-butadiene, polyisoprene and divinyl rubbers, a vulcanizing group, carbon black in the indicated quantities (see RU 2286363 C2, 10.27.2006 )

The technical task of the invention is to increase the service life of the strip (operating hours), the coefficient of friction for steel while maintaining the specific volume resistance to electric current.

The technical result is achieved by the fact that it is proposed to use a composite material consisting of a rubber compound, a particulate filler and crushed rubberized cord fibers for the manufacture of rail shock absorber pads.

The significance of the differences in the claimed composition of the composite material is determined by the fact that the composition contains rubberized fibers of a polyamide cord, for example kapron cord, crushed to a length of 10 to 15 mm, crushed extruders from the vulcanization stage of the shock absorbers and crushed rubber crumb with a particle size of from 0.5 to 1 mm, while the components should be taken in the following ratio, wt.%:

specified fibers 17-18,5 specified rubber compound 77-78 specified extrusions 2 crushed rubber crumb 2-3,5

Rubber crumb can be obtained in the same production of gaskets-shock absorbers, can also be used waste from other industries containing crushed rubber fibers in the composition.

This composite material contains a rubber mixture based on methyl styrene and divinyl rubbers. The polymer binder incorporates a vulcanizing group and inactive carbon black, taken in traditional and well-known proportions.

Table 1 Composition Recipes Name of material Hitch, wt.% one 2 3 Fibers 18.5 17.0 eighteen Rubber compound: 77 77.5 78 - SKD brand 2 - SKMS-30 ARKM15 - composition of the vulcanizing group: dithiodimorpholine, hexol HPI, ethyl cimate, sulfur - Carbon black N660 Vypressovka 2 2 2 Baby 2.5 3,5 2

table 2 Distant analogue Near analog Products according to the invention one 2 3 Operating time, mln tons 1000 1100 1200 1700 1300 Volume resistivity, Ohm · cm 10 ¹⁰ 1,0 · 10 ¹⁰ -1,2 · 10 ¹⁰ 10 ¹⁰ 10 ¹¹ 10 ¹⁰ × Friction coefficient for steel (sliding friction between the sole of the rail and the shock absorber pad) 0.4 0.5 0.55 0.6 0.55 × Sliding friction coefficient: - The ratio of the force moving the load to the force pressing this load. Dimensionless quantity.

As can be seen from the tables, the products made according to the invention have an operating time of missed cargo significantly higher than that of the analogue closest in technical essence and achieved result. Also, performance indicators, like the coefficient of friction for steel, are higher than for analogues. In this case, the specific volume resistance to electric current remained at the level, and in some cases even increased. Products according to option No. 2 have an optimal set of operational indicators.

Claims (1)

The composition of the composite material for rail shock absorber gaskets, including crushed rubberized polyamide cord with a fiber length of 10 to 15 mm, a rubber mixture based on methyl styrene and divinyl rubbers, containing a vulcanizing group and inactive carbon black, as a dispersed filler, crushed moldings from the stage vulcanization of gaskets-shock absorbers and crushed rubber crumb in the following ratio of components, wt.%:
specified fibers 17.0-18.5 specified rubber compound 77-78 specified extrusions 2 crushed rubber crumb 2.0-3.5