DE202011003770U1 - Brake pad for railway vehicles - Google Patents

Abstract

Brake block for railway vehicles with a metal frame and at least one single-layer friction element (10) made of a composite with wear indicators (9) and protection against incorrect use of the brake block type, characterized in that the metal housing is designed as a wire frame which is integrated into the composite Pressed perforated plate (3) and two in the composite material of the brake pad back as a circumferential pressed and closed wire frame (2) and that the inner parts of the wire frame (2) overlap each other, are bent outwards of the brake pad back and a central eye (4) to Insert a wedge (5).

Description

The invention relates to a brake pad for railway vehicles according to the preamble of claim 1. The brake pad can be used for example in passenger and freight cars, in electric trains, in subways etc.

From the prior art brake pads are known, including cast-iron, wheel-friendly composite brake pads that are used for railway cars. The composite pads have one or more friction liners of a stronger material as a primary composite material, for example of high strength ductile iron, in their design. Such pads ensure a stable braking effect, especially in the spring-summer period, as well as repair the wheel tread in a normal braking. The bike-friendly composite brake blocks are with inserts made of special cast iron in recent years by the company "Railroad Friction Products Corporation" under the brand name "Cobra Tread Guard ^®" in the US and by the company "FRITEX" branded "FRITEX CONTACT ^® »series production in Russia.

• – gestanzt aus einem Stahlband in Form von Rücken seitens BKS-Rückens und mit U-förmiger Zentralerhebung aus einem Stahlband (Zentralauge);
• – Drahtgittergehäuse, das eine innere Verstärkung der BKS-Rückseite sicherstellt und aus einem Drahtgehäuse und Gitter oder aus in Verbundstoff auf der BKS-Rückseite eingepresstem Lochblech besteht.

The composite brake pads, including those with cast iron inserts, may in the composition have one or more longitudinal composite layers that differ in strength and wear resistance. The layer on the side of the brake pad layer (BKS) back has better strength and better adhesion properties than the friction layer, for example by an increased proportion of binding and reinforcing fibers. The abzureibende layer is close to the friction layer in the mechanical and friction properties, but differs by a smaller wear resistance. The composite brake pads, including those with hard friction inserts, are made with a metallic housing. The case is normally made in two types:

• - stamped from a steel band in the form of backs from BKS-back and with U-shaped central elevation of a steel band (central eye);
• - Wire mesh housing, which ensures an internal reinforcement of the BKS back and consists of a wire housing and grid or in pressed composite in the BKS back perforated plate.

The UCS back has a U-shaped center eye and two side cams. The center eye has an opening for inserting a wedge that connects the pad to the metal sole.

Several brake pads are known:
«Brake pads for railway vehicles (examples)» after the Russian Invention Patent No. 76881 ,

This type of brake pads is one of the strongest and most reliable types. The brake pad is inexpensive in production and quiet. Its minimum thickness is in the range of 10 mm. The design of such brake pads has proven to be reliable in multi-year operation under severe conditions in the far north, in continental, temperate and subtropical climates.

The essential BKS features of the known brake pads mentioned below are also characteristic of the essential BKS features of the new brake pads. The brake pad has a composite friction element. On the reverse side of the BKS, two closed and interconnected frames are pressed in all around. The inner frame sides overlap each other, are bent outwardly of the UCS back and form an eye for insertion of a wedge. A metal grid or a perforated plate is pressed into the friction material of the BKS back. A brake pad for railway vehicles may comprise at least one single-layer composite friction element, in the back side of a curved perforated steel strip and a wire skeleton are pressed. The wire skeleton is formed of two interconnected frames. Each frame is bent from wire. The wire ends are connected and the joint is made without thickening the wire skeleton. The connection point is arranged in the region of the outer side surface. The brake pad can additionally be provided with at least one connected to wire skeleton hard friction insert. The hard friction insert may be formed of high strength or malleable cast iron.

Is known a brake pad for railway vehicles from the Russian patent for invention No. 2309072 , The peculiarity of this known brake pad is a hard friction insert made of high-strength or malleable cast iron, which repairs the wheel tread during normal braking. The essential distinguishing features of the known brake pad, including the hard friction insert made of high-strength or malleable cast iron and the ratio of the friction surface of the insert to the total friction surface of the brake pad of 4 to 20%, are also characteristic of the essential distinguishing features of the new brake pad.

Also known is a brake pad for railway vehicles from the Russian Patent No. 2340805 , This known brake pad has a hard friction lining. The upper part of the The brake pad is caught in the wire frame. This type with a cast iron insert is currently mass-produced and represents one of the simplest, most reliable and cheapest type in the world. The essential features of the known brake pad, such as «composite friction element», «hard friction insert clamped in the wire frame» and «perforated plate or grid , which are pressed in the back of the friction element made of composite », are also to be regarded as essential features of the new brake pad.

Also known is a brake pad from the Russian Patent No. 2372230 , This known brake pad comprises a wire skeleton and a metal insert, which are embedded by means of molding in a friction material.

The disadvantage of all known types is the impossibility of recognizing the composite friction element according to the frictional properties. The friction properties are in the EU countries in the leaflet UIC 541-4 OR (Brake Brakes with Composite Brake Pads - General Conditions for Certification of Composite Brake Block Soles) of the International Union of Railways.

• – mit hohem Reibwertniveau (K);
• – mit mittlerem Reibwertniveau (L);
• – mit niedrigem Reibwertniveau (LL).

According to this leaflet UIC 541-4 OR For example, the brake pad includes a composite friction member mounted on a metal housing. It is designed as a steel strip in the back of the brake pad. The central eye is formed as a U-shaped elevation of a steel strip. According to the leaflet, the following brake soles may be used in international traffic:

• - with high coefficient of friction (K);
• - with average coefficient of friction (L);
• - with low coefficient of friction (LL).

Protection of brake pads type K (according to 9 "Protection against incorrect use of the K-sole, p. 62 in the leaflet) is designed as a conical metal insert. The inserts pass symmetrically through the steel strips with respect to their transverse plane. This transverse plane passes over the central eye and the openings in the brake pad back. The openings also pass symmetrically through the steel strip with respect to the transverse plane passing over the central eye. Said openings are arranged between the tapered friction liners, wherein the locations of the tapered friction liners (78.5 ± 1 mm from the transverse plane passing through the central eye of the brake pad) and the locations of the apertures (39 ± 1 mm from the transverse plane passing through the central eye of the pad ) according to the leaflet UIC 541-4 OR are regulated. The lack of protection against incorrect use on the back of the BKS leaves the brake pad in the brake pad not insert, since the brake pad itself is provided with the protection. The protection of the brake pad is designed as a conical elevations and openings. In the construction of the protection of the brake pad engages the protection of the brake shoe, and thus the brake is built. In addition, in 10 «Design examples for wear indicators» on page 63 of the leaflet the arrangement of the wear indicators is shown. This arrangement is to secure the BKS wear to the indicator without wear-enhancing parts and housing. Such pads are approved for use in the European Union.

In the UIC 541-4 OR described type of brake pads represents the closest type with respect to the totality of the essential features and is selected as a prototype. Common essential features of the new brake pad and prototype are a metal body and a composite friction element with wear indicators.

The disadvantage of the prototype is the metal housing in the form of steel strips and the central eye made of steel. This construction, by securing a rigid structure of the housing as a whole, does not ensure required strength in the U-shaped elevation. The survey is formed by bending the flat steel strip in a bending punch. When punching micro-cracks form in the bends, which become larger with constant vibration and load during operation. The housing breaks. Under the effect of increased stress, the weld also breaks. One half of the brake pad breaks off from the other half. Due to the vibration and an alternating load under extreme operating conditions, eg. As severe frost, the composite friction element separates from the metal housing in some cases.

It is an object of the invention to provide a composite brake pad for railway vehicles, which ensures safe international rail transport between EU and CIS countries and other countries with different climatic conditions and traffic conditions and avoids the disadvantages of known brake pads.

The stated object is solved by the features of claim 1.

The aim is to increase the strength of the brake block type and to meet all the safety and certification requirements of the abovementioned countries. It should be z. For example, Russian requirements for frost resistance and German requirements for composite brake pads, which may contain no lead and no other substances in the composite, and other requirements are met.

The technical result of the new brake pad is to increase operational safety and ensure safe international traffic between the EU, CIS and other countries with different climatic conditions. The technical result of the new design is also an increase in the strength of the brake pads, ensuring protection against incorrect use, increasing a stable braking effect, ensuring the repair of the wheel tread under normal braking, increasing the wheel and Bremsklotlebensdauer, noise reduction, an increase heat dissipation into the environment, a reduction in the cost of the brake pads and a fulfillment of the requirements of UIC, CIS countries and others on the brake pads for railway vehicles.

To achieve this technical result, a metal housing of the brake pad, consisting of a metal skeleton and a friction element made of a composite material with wear indicators, is designed as a wire mesh skeleton. The wire frame represents two closed frames circumferentially pressed into the composite on the back of the pad. The inner parts of two closed frames overlap on both sides, are bent outwardly of the UCS back and form an eye for insertion of a wedge. The brake pad comprises in the back of a metal grid or a perforated plate which is pressed into the composite. The main advantage of the composite block with a wire mesh skeleton, unlike composite composite blocks with a steel housing, is that the composite center eye is made with an internal reinforcement. This increases the resilience characteristics of the pad and thus its impact and vibration resistance and eliminates tearing of the composite from the housing. Such pads compared to composite block pads with all-metal housing made of steel strips (spine) have a longer life and reliability. It is essential that the metal costs, the brake pad price and the noise during operation are lowered. Many years of practical use of brake blocks of this type in the far north, in continental temperate and subtropical climates confirmed their absolute reliability.

The connection of the frame wire ends can be carried out both without thickening of the wire skeleton in the pad thickness and with thickening of the wire skeleton in the pad thickness and with an arrangement in the Gerippehälfte in the region of the outer side surface of the brake pad.

The composite brake pad may be made with one or more hard friction liners or without liners. The hard friction inserts can be made of metal, z. B. made of high-strength cast iron with nodular graphite. The use of such a cast iron has a cleaning effect on the wheel during normal braking and at low temperatures. Here, the tread roughness and the stable braking effect is increased, especially in the spring-summer period. During normal braking and at high temperatures, the cast iron fills the microcracks on the wheel surface, thus preventing further cracking. In addition, the wheel tread is improved, and the resistance against crumbling and other defects and hence the wheel life are increased.

The hard Reibeinlage can be useful connected to the wire frame in terms of length, width and from one side in height, z. B. by pinching in skeletal openings. Thus, the friction insert can be pressed together with the wire skeleton in the brake pad. The hard insert can be clamped in the wire frame and connected to the wire skeleton on another meadow. This depends on the design of the wire skeleton and the insert. The central eye with an opening for the wedge, reinforced with vertical elements of the hard friction insert and with the wire skeleton, is made of a robust and elastic composite together with the lateral cams. The hard friction liners can be made of a special composite with metallic or other special fillers. The composite brake pad may be made with or without a recess on the side of the friction surface of the brake pad and may comprise a one, two or three layer composite friction element.

In order to prevent faulty assembly, the type K brake pad is provided with protection against misuse. The protection is designed as a conical elevations on the back of the brake pad. These elevations are formed of the same composite material as the friction element, since they are pressed together with the brake pad in a pressing tool with conical openings to the arrangement points of the elevations. On the back of the pad and openings in a passing through the central eye transverse plane are symmetrical. The dimensions, shape and arrangement of the conical projections and the openings are on the back of the pad according to the leaflet UIC 541-4 OR arranged.

1 shows a view of the brake pad for railway vehicles, wherein the brake pad comprises the following parts:

LIST OF REFERENCE NUMBERS

1

the layer of the frictional element of a composite material having a hard intact friction and abridged property, a metal housing comprising a wire frame 2 with a perforated plate or grid 3 .

4

a central eye with an opening for a wedge 5 .

6

two lateral cams,

7

two conical openings,

8th

two surveys,

9

two wear indicators as recesses and

10

the hard friction insert.

• – die Herstellung (Gießen) der Bremseinlage aus Gusseisen,
• – die Herstellung des Arbeitsstücks aus Lochblech,
• – die Herstellung und das Schweißen des Drahtgerippes,
• – den Zusammenbau des Drahtgerippes mit der Bremseinlage durch Einklemmen,
• – die Herstellung der Verbundstoffe für die intakte und die Reibschicht,
• – das aufeinanderfolgende Einlegen des Arbeitsstücks aus Lochblech und des Drahtgerippes mit der Reibeinlage, die Auswaage inaktiver und der Reibschicht, die Glättung der Verbundstoffe und ein nachfolgendes Formpressen,
• – die Vulkanisation der Bremsklötze im Presswerkzeug unter Druck und Temperatur, gegebenenfalls auch einer Wärmebehandlung im Ofen,
• – das Bohren der Öffnungen für den Keil und die Aussparungen der Verschleiß-Indikatoren im Bremsklotz, wenn diese im Presswerkzeug nicht vorgesehen sind.

The production technology of the brake pad provides the following steps:

• The manufacture (casting) of the cast iron brake insert,
• - the manufacture of the work piece from perforated sheet,
• - the manufacture and welding of the wire skeleton,
• - the assembly of the Drahtgerippes with the Bremseinlage by pinching,
• The production of the composites for the intact and the friction layer,
• The successive insertion of the piece of work piece made of perforated plate and the wire skeleton with the friction insert, the balance inactive and the friction layer, the smoothing of the composites and a subsequent compression molding,
• - the vulcanization of the brake pads in the pressing tool under pressure and temperature, optionally also a heat treatment in the oven,
• - The drilling of the openings for the wedge and the recesses of the wear indicators in the brake pad, if they are not provided in the pressing tool.

By way of exception, if a rusted wire or fouled metal fitting is used or special brake pad strength requirements are imposed, de-rusted, degreased and coated with adhesive to improve the adhesion and bonding of the metal fitting to the composite friction element.

To form conical elevations, two conical openings 6 mm deep and 12 to 10 mm in diameter are formed in the bottom of the mold. The distance of each aperture from the transverse mirror plane passing through the central eye is 78.5 ± 1 mm. The apertures in the back of the pad of 15 ± 1 mm in diameter and spaced from the transverse mirror plane of 39 ± 1 mm may either be drilled after manufacture of the pad or stamped in the die during the course of the pad formation.

All production steps, including the installation of the wire tiller with the friction insert, are described in detail in the cited regulations and can easily be repeated on systems of brake pad producers.

The brake pads of the new design for railway vehicles can be used in international rail traffic between EU, CIS countries and other countries with different climatic conditions and railway conditions. As a result, the reliability increases and ensures a safe international rail traffic. In addition, an additional profit for the railway is secured.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• RU 76881 [0005]
• RU 2309072 [0008]
• RU 2340805 [0009]
• RU 2372230 [0010]

Cited non-patent literature

• UIC 541-4 OR [0011]
• UIC 541-4 OR [0012]
• UIC 541-4 OR [0013]
• UIC 541-4 OR [0014]
• UIC 541-4 OR [0024]

Claims (8)

Brake block for railway vehicles with a metal skeleton and at least one single-layer friction element ( 10 ) of a composite with wear indicators ( 9 ) and a protection against a faulty use of the brake pad type, characterized in that the metal housing is formed as a wire skeleton, which is a pressed-in the composite perforated plate ( 3 ) and two in the composite material of the brake pad back as circumferentially pressed and closed wire frame ( 2 ) and that the inner parts of the wire frame ( 2 ) overlap each other, are bent outwards of the brake pad back and a central eye ( 4 ) for inserting a wedge ( 5 ) form. Brake block for railway vehicles according to claim 1, characterized in that the protection of the brake pad as surveys ( 8th ) and openings ( 7 ) in which with the perforated plate ( 3 ) or formed with a grid-reinforced composite. Brake block for railway vehicles according to claim 1, characterized in that the connection of the frame wire ends is formed without a thickening in the total thickness of the brake pad. A brake pad for railway vehicles according to claim 1, characterized in that the connection of the frame wire ends is carried out with a thickening of Drahtgerippedicke with an arrangement in a Drahtgerippehälfte in the region of the outer side surface of the brake pad. Brake block for railway vehicles according to claim 1, characterized in that it comprises at least one friction insert ( 10 ) having. Brake block for railway vehicles according to claim 1, characterized in that at least one friction insert ( 10 ) consists of high-strength or malleable cast iron. Brake block for railway vehicles according to claim 1, characterized in that the ratio of the friction surface of the hard friction insert ( 10 ) to the total friction surface of the brake pad is 4 to 20%. Brake pad for railway vehicles according to claim 1, characterized in that the wear indicators ( 9 ) are formed as recesses or opening.

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