RU2414365C2 - Method of continuous control over locomotive braking clamp thickness and device to this end - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to railway transport and may be used at traction rolling stock. Control is performed by metal warners. Warner consists of metal core, plastic tip and lead-out conductor. At tolerable wear of braking clamp, warner metal part is reached to close electric circuit. Here, warner closes to switch on indicator lamp to warn operator about maximum wear of braking clamp to be replaced. To define locomotive side whereat worn-out braking clamp is located, locomotive is provided with two, RH and LH, circuits to switch on RH or LH indicator lamp, respectively.

EFFECT: increased railroad traffic safety.

2 cl, 3 dwg

Description

The invention is intended for use on traction rolling stock and relates to part of the brake linkage, as well as to signaling devices of wearing mechanical parts.

Brake pads (lining) are the most important element of the mechanical part of the brake. The effectiveness of braking and, therefore, the safety of movement depends on them - this causes a number of requirements for their quality and characteristics:

- the presence of a stable and high coefficient of friction in a wide range of speeds and pressing forces;

- minimal wear per unit of braking distance to reduce the amount of work on replacing pads on rolling stock;

- the possibility of prolonged braking without loss of frictional properties;

- the absence of unacceptable thermal and other influences on the wheelset or wheel damaging their surface;

- the invariability of frictional characteristics when moisture enters the pads;

- ease of installation when replacing due to wear or changing the type of brake pads;

- elimination of occurrence of non-conductive inclusions on the wheel surface (third body), as well as reducing its coefficient of adhesion to rails;

- the absence of wear products harmful to humans and the possibility of spontaneous combustion of pads [1].

The quality of the brake pads depends on reducing braking distances, increasing speeds and driving safety. Brake pads should have a high coefficient of friction, which does not depend on speed, high wear resistance and work stably in different climatic conditions [2].

Brake pads are divided into categories according to the type of material from which they are made, and the form of execution. In accordance with the first in our country, three types of pads are produced: standard cast iron, composite and cast iron with a high phosphorus content (phosphorous), and in accordance with the second: ridge, comb and section.

On locomotives, cast iron standard pads are mainly used (1, Fig. 1). Their advantages include a good heat dissipation during braking and the absence of moisture influence on the friction coefficient. At the same time, such pads have a significantly unstable coefficient of friction, which decreases with increasing speed. This, in particular, leads to the need to use on the high-speed rolling stock of the regulators the forces of pressing the pads depending on the speed [1].

The main problem is that cast-iron blocks wear out quickly, which reduces the safety of the train moving on the stage (descent). On steep, long descents, for example, the wear of cast-iron blocks per run is 7–9 mm [1].

Composite brake pads are used on all freight, as well as passenger cars, which are operated at speeds of more than 120 km / h. They are made according to a certain technology from asboka-rubber materials with the addition of baride, soot and a vulcanizing composition by pressing onto a metal frame. They are 3-5 times more wear resistant than cast iron. The disadvantages of these pads include poor heat dissipation and, as a result, adverse temperature conditions on the wheel's surface, causing them damage in the form of fatty deposits, metal shifts, microcracks, etc. They are not used on locomotive wheels due to overheating, weakening and possible sliding of the bandage. In addition, when moistened, especially in winter due to snowstorms and snowfall, the composite pads are moistened and iced up, which requires periodic activation of the brakes to dry them [2 |.

Ridge standard cast-iron pads (Fig. 1) are used on locomotives if, due to traction equipment, it is impossible to connect them in pairs with triangles or brake beams. Since the surface of the wheels has a conical shape and when you press the block, in addition to the normal force, there is also a lateral force, it is prevented from sliding using a special curly groove that rests on the wheel flange.

The wear of the pads under operating conditions significantly depends on the strength of their pressing, the material, the type and duration of braking, the adjustment of the linkage, the position of the pads relative to the surface of the wheel, both in the brake and in the released state, and a number of other factors. The minimum thickness during wear is 14 mm.

Currently, brake pads are produced, with a wire mesh frame, which have a greater vibration strength than with a metal frame, lower weight and allow wear up to 10 mm.

In operation, the cast iron brake pad of a locomotive wears out rather quickly to a critical thickness, which leads to the need for its replacement [1]. However, in modern conditions of operation of the brake pads of locomotives, it is impossible to provide continuous monitoring of its wear during movement, and, consequently, timely replacement. Thus, the closest prototype is the cast iron brake pad of a locomotive [1].

Currently, the thickness of the brake pads is controlled by assistant drivers using a ruler or vernier caliper in the parking lot of the locomotive. However, due to the difficulty of predicting the wear of the block, as well as the presence of the so-called “human factor”, it is impossible to predict its thickness in the locomotive circulation section due to the difference in the modes of train driving by the drivers.

A method for controlling the thickness of the brake pads of a locomotive in operation is proposed. The method consists in continuously monitoring the thickness of the pads and issuing a signal when the minimum thickness is reached. The proposed control method will eliminate the above disadvantages regarding the impossibility of obtaining reliable data on wear.

It is proposed to provide control with metal signaling devices (3, FIG. 2). They are included in the design of the pads through additionally made holes. The signaling device (3) consists of a metal part (conductor) (5), a plastic case (insulator) (6) and a connecting individual wire (4) (figure 2). During operation, upon reaching the maximum allowable wear (size a in FIG. 2) of the brake pad, the plastic part of the indicator contacts the rotating wheel (wheel bandage) (8, figure 3) and, due to the wear of the plastic part of the indicator, the metal part of the indicator ( 5, FIG. 2) closes the electric circuit to “minus”. Size a - the maximum allowable wear of the block, depends on various factors: the profile of the path of the locomotive circulation section, the degree of wear resistance of specific blocks, as well as the type of locomotive and is set by the instruction.

The method of continuous monitoring of the permissible wear of the brake pad works as follows: when the circuit is closed, the current flows but the lines (Fig. 3): “+” of the power source, through the current-limiting resistance (13), through a signal lamp (incandescent lamp, or LED and other indicators) (11) located in the locomotive driver’s cab on the control panel (12), through the common wire (9), through the individual wire (10) of the indicator (Fig. 3), through the metal part (5, figure 2) of the indicator (3, figure 2), brake pads (7, figure 3), on a metal bandage eights Wheels (8, 3) and on the rail (14, 3), which is connected to "-".

When critical wear is reached, the indicator (3, FIG. 2) closes, the lamp (13, FIG. 3) lights up and indicates to the driver that the wear of one of the pads on the locomotive has reached the limit level and, accordingly, it requires at the nearest service station replacements.

Depending on the series, from 6 to 12 brake pads are used on each side of the locomotive. It is proposed to determine on the sides of the locomotive where the block is extremely worn out, two values are set for the locomotive (right and left), respectively, either the left or right lamp (L, P) lights up in the driver's cab (13, Fig. 3). The number of signaling devices per block can be any from one to N. Figure 2 shows the case when N = 2.

The technical result of the proposed method for continuous control of the thickness of the brake pads of a locomotive in operation is as follows:

- improving the safety of train traffic by increasing the reliability of braking of all pads of a locomotive, in connection with the timely replacement of extremely worn pads;

- timely indication to the locomotive driver of the maximum wear of the brake or brake pads of the locomotive during operation;

- the opportunity for the locomotive driver to adjust his actions when braking in the upcoming sections of the track profile;

- low cost of necessary additions to the design.

Literature

1. Automatic brakes of rolling stock. / V.R. Asadchenko. - M.: Route, 2006 .-- 392 p.

2. Automatic brakes of rolling stock. / V.I. Krylov, V.V. Krylov. - M .: Transport, 1983. - 360 p.

Claims (2)

1. A method for continuously monitoring the thickness of the brake pads of a locomotive in operation, visually determined by the assistant driver, characterized in that the maximum wear limit signaling is carried out directly during operation and is visually displayed to the driver in the form of a light signal by using a device for continuous monitoring of the thickness of the brake pads. 2. The device for continuous control of the thickness of the brake pads of a locomotive in operation for implementing the method according to claim 1, characterized in that from one to N signaling devices consisting of a plastic case and a metal part included in the electric circuit are included in the design of each brake pad through additional holes through which, when the plastic case is worn through an individual wire and a common wire, the electrical connection of the metal part of the signaling device with the signal lamp is provided, ennoy to render the wear limit of the brake shoe locomotive drivers, plus the power source circuit through a current-limiting resistor, intended to protect the lamps from overcurrent, is closed through the wheel on the rail brace (minus).

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