RU2463185C2 - Method of rolling stock brake pads production - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to railway transport, particularly, to method of rolling stock brake pads manufacturing. The method consists in manufacturing metal structure with flat-topped projection in its central part, use of composite friction element and one hard insert located in central part of pad. Into formulation of composite friction element based on butadiene or btadien-nitril rubbers, following is introduced: pretreated on heated to 40-80°C roller press mixture of hard high-molecular dian resin with molecular mass 860 to 3500 (A) with aromatic polyamine (crude product) representing mixture of isomers of diaminodiphenylmethane and higher polyamines (B) in the A:B ratio of 95:5 to 70:30; vulcanising agents - sulphur, 2-mercaptobenzothiazole, thiuram, dried fibrous filler, presoaked with water epoxy dispersion in quantity of 5 to 40% on dry basis and powder filler representing fine mineral or metal or their mixture. Hard insert made of cast iron is anchored by friction composite element during pad pressing in die mould due to high adhesion and cohesion properties of friction composite element.

EFFECT: higher functional reliability of brake pads due to increase in strength and adhesion to metal of friction composition, as well as lower labour and energy consumption during pads manufacturing due to elimination of welding operation.

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Description

The invention relates to the field of railway transport, and in particular to a method for manufacturing brake pads of a rolling stock.

A known method of producing brake pads from composite materials based on butadiene rubbers with vulcanizing additives and fillers - asbestos fiber and various mineral powders in combination with a metal frame (see B. A. Shiryaev. Production of brake pads from composite materials for railway cars. M. : Publishing house "Chemistry", 1982). The described composition - a composite friction element is the most common in the manufacture of pads for more than 50 years. However, the increase in railway speeds and loads on the brake devices showed insufficient strength and reliability in the operation of brake pads obtained by the known analogue.

The closest prototype of the claimed solution is a brake shoe and a method for producing it, which, along with a composite friction element and a metal frame with a U-shaped protrusion in its central part, contains a solid cast iron insert, while the insert is welded to the metal frame (see RF Patent No. 2309072 C7 dated 10.27.2007).

The task of the solid insert is to provide a cleaning and polishing effect on the wagon wheel.

However, welding the insert to the metal frame causes internal stresses in the metal of the frame and, as a result, a decrease in its strength and reliability. At the same time, welding the insert is a rather time-consuming operation, unacceptable in the mass production of brake pads. In addition, all described and used composite friction elements (compositions) have insufficient strength and adhesion to the metal elements of the pads.

The aim of the present invention is a method of increasing the operational reliability of brake pads by increasing the strength and adhesion of the friction composition to the metal, which reduces labor and energy costs during manufacture by eliminating the welding operation.

This goal is achieved by the fact that a mixture of a solid high molecular weight Diane resin with a molecular weight of from 860 to 3500 (A) with an aromatic polyamine (technical product) is introduced into the composition of the composite friction element based on butadiene or butadiene nitrile rubbers ), which is a mixture of isomers of diaminodiphenylmethane and higher polyamines (B) in a ratio A: B from 95: 5 to 70:30, vulcanizing additives: sulfur, 2-mercaptobenzthiazole, thiuram, dried fibrous filler, pre-impregnated with aqueous epoxy dispersion, in an amount of from 5 to 40% in terms of dry product and powder filler, which is a finely divided mineral or metal or a mixture thereof, and a solid insert made of cast iron is fixed with a friction composite element during the pressing of the block in the mold due to the high adhesive and cohesive properties of the friction composite element, consisting in parts by weight:

Rubber 100.0 A mixture of epoxy with aromatic polyamine 10.0-40.0 Sulfur 1.0-15.0 2-mercaptobenzthiazole 0.5-4.0 Tiuram 0.03-1.0 Fiberfill 20.0-140.0 Powder filler 40.0-260.0

Example 1

Preparation of a mixture of epoxy resin with aromatic polyamine.

A mixture of solid high molecular weight Diane resin with a molecular weight of 1600 grade E-44 (TU 6-10-1347-78), component A, in an amount of 85 parts by weight, is loaded onto rollers heated to 60 ° C and 1.25 friction. and aromatic polyamine, which is a mixture of isomers of diaminodiphenylmethane and higher polyamines (TU 2473-342-05763441-2001), component B in an amount of 15 parts by weight After 3 cuts, the softened mass is removed from the rollers, cooled, crushed and packaged. Permissible shelf life of at least 6 months.

Fibrous preparation

In the paddle mixer load 80 wt.h. chrysotile asbestos brand P-5-65 and 40 parts by weight 50% aqueous epoxy dispersion (in terms of dry weight of 20 parts by weight) of Etal AK-732 grade (TU 2241-824-18826195-06), which is the product of the interaction of a mixture of diane and aliphatic resin with polyethylene glycol. After stirring for 15 minutes, the impregnated fiber is sent to a dryer to remove water. The impregnated dry fiber is an odorless, pulverized, non-dusting, non-toxic pulp easily disintegrating with little tensile strength.

Obtaining a composite friction element

In the rubber mixer type RSVD-140-20 load 100 wt.h. butadiene rubber grade SKD-2 (GOST 14924), 25 parts by weight 5-wt. parts of E-44 resin rolled off at 60 ° C with polyamine sulfur, 2.2 parts by weight 2-mercaptobenztaazole (GOST 739), 0.5 parts by weight Tiurama (GOST 740), 90 parts by weight impregnated with epoxy dispersion of chrysotile asbestos and a mixture of 150 parts by weight powdered mineral filler, consisting of a mixture - alumina (GOST 30558), crystalline graphite (GOST 5279), barite concentrate (GOST 4682) in equal proportions. Stirring is carried out at 70 ° C for 30 minutes. After mixing, the bottom gate of the rubber mixer opens and the mass is sent for the manufacture of brake pads.

Shoe Making

For the manufacture of pads, the composite material is preformed (briquetted) under a pressure of 130 MPa for 10 seconds.

In the process of briquetting, the mixture is poured into an empty mold socket of the corresponding design, after which a metal frame and a metal insert are laid, the mold is closed and pressure is applied. Finished briquettes are sent to molding and vulcanization in heated molds.

The formation and at the same time vulcanization is carried out at a temperature of 200 ° C ± 5 for 25 min +1 min / mm of the thickness of the composite friction element.

Examples 2-6 are carried out analogously to example 1 with a change in parameters in accordance with table 1.

The characteristics of the brake pads are shown in table 2.

From the data table shows the benefits of the pads obtained by the present method compared with mass-produced in accordance with TU 2571-037-00152129-2006.

Table 1 The conditions for the implementation of the proposed method according to examples 2-6 No. p / p Parameter Name The value of the parameter in the examples: 2 3 four 5 6 one Type and brand of rubber used Butadiene SKD-1 Butadiene-new SKD-2 Nitrile butadiene SKN-26 A mixture of butadiene SKD-1 and butadiene-nitrile
SKN-18 1: 1 Butadiene triyl SKN-40 2 The number of vulcanizing additives: sulfur one fifteen 5 5 5 2-mercapgobenzthiazole 0.5 four 2 2 2 tiuram 0,03 one 0.5 0.5 0.5 3 Grade and molecular weight of solid epoxy ED-8 (GOST 10587-84)
860 E-49 (TU 2225-039-0020
4211-2003)
2800 ED-8 (GOST 10587-84)
1000 E-05K (TU 2225-008-00204211-96)
3500 ED-8 (GOST 10587-84)
900 four The amount and ratio of resin and aromatic polyamine (A: B) 10 40 25 25 25 95: 5 70:30 85 85 85 5 Mode of rolling of resin with aromatic polyamine, temperature 0 ° С 40/10 80/3 60/5 60/5 60/5 6 Type and amount of fibrous filler, parts by weight 12 micron alkali-free continuous chopped fiberglass Polyaramide fiber 18 micron continuous basalt chopped fiber Ground Arselon fiber (TURB 00204056.145-97) twenty 140 one hundred one hundred one hundred 7 Fibrous Epoxy Dispersion Content 5 40 22 22 22 8 Type and amount of powder filler, parts by weight Calcined dialyte crumb (TU 5761-003-25310144-99)
260 Iron powder 1: 1
150 Electrocorundum and crushed steel powder
150 A mixture of carbon technical and alumina grade G-00 in a ratio of 1: 1
150 A mixture of iron oxide and crystalline graphite in a ratio of 2: 1
150 9 Insert material Ductile iron High-strength
cast iron Gray cast iron Phosphor cast iron Ductile iron

table 2 The properties of brake pads made by the present method according to examples 1-6 No. p / p Name of indicator The value of the indicator for examples 1-6 one 2 3 four 5 6 one Brinell hardness, HB 16/187, 5/30 3,5 3.8 3.6 3,5 3.8 3.6 2 Friction coefficient paired with grade 1 and 2 steel according to GOST 10791 0.41 0.40 0.43 0.39 0.45 0.43 3 Wear paired with steel grade 1 or 2 according to GOST 10791, mm 0.12 0.10 0.12 0.11 0.10 0.11 four The limit of compressive strength, MPa 35 32 38 32 36 35

Claims (1)

A method for producing brake pads of a rolling stock, including the manufacture of a metal frame with a U-shaped protrusion in its central part, the use of a composite friction element and one solid insert located in the central part of the shoe, characterized in that the composition of the composite friction element is based on butadiene or butadiene nitrile rubbers introduce a mixture of solid high molecular weight Dianova resin with molecules pretreated on rollers heated to 40-80 ° C with a gross mass of 860 to 3500 (A) with an aromatic polyamine (technical product), which is a mixture of isomers of diaminodiphenylmethane and higher polyamines (B) in a ratio of A: B from 95: 5 to 70:30, vulcanizing additives — sulfur, 2-mercaptobenzothiazole , thiuram, dried fiber filler, previously impregnated with aqueous epoxy dispersion in an amount of 5 to 40%, calculated on the dry product, and a powder filler, which is a finely divided mineral or metal, or a mixture thereof, and a solid insert made of cast iron is fixed dissolved friction element composite during pressing pad in the mold due to high adhesive and cohesive properties of the composite friction element comprising, in parts by weight .:
Rubber 100.0 A mixture of epoxy with aromatic polyamine 10.0-40.0 Sulfur 1.0-15.0 2-mercaptobenzthiazole 0.5-4.0 Tiuram 0.03-1.0 Fiberfill 20.0-140.0 Powder filler 40.0-260.0