RU2746165C1 - Method for frictional compensation of movements of continous welded rail track and device for its implementation - Google Patents

Abstract

FIELD: railways.

SUBSTANCE: group of inventions relates to the field of the superstructure of a railway track, in particular to methods of frictional compensation of movements of a continuous-welded rail track, as well as to devices for its implementation. The device contains rails, lodgements on the sleeper grid, compensation blocks and fixing bolts. The bushings of the vertical supports of the lodgements and the body of the frictional compensation unit are equipped with threads. The rails are fixed in the cradle, while bolts are screwed on one side, and the block body on the other. The compression force of the rail web is created through floating elongated pads. The compressive force creates a frictional force and prevents the axial movement of the rails relative to the sleeper grid.

EFFECT: automation of control of temperature and power movements.

6 cl, 2 dwg

Description

The method of frictional compensation of movements of a continuous welded rail track and a device for its implementation refers to railway transport, in particular to compensation of force and temperature movements of a rail track and can be used in the assembly of equalization spans and butt joints of welded strings, to control the stress-strain state, to resist forces hijacking, braking, on slopes and passes for tightening and pinching parts.

In mechanical engineering, when it is necessary to create large forces during stamping, drawing, and other operations, instead of hydraulic and pneumatic devices.

A known method for compensating the temperature gaps of a continuous-welded rail track, containing rails, side plates, fasteners, pre-tightening, a compensation unit including solid-state and liquid expansion joints and expansion joint heaters [1]. The disadvantage of this method is a narrow area of application, to reduce the gaps in the butt joints of the rails.

The known method of frictional compensation of movement of the rail track, taken as a prototype, containing under the rail base, sleepers, rails, compensation blocks, program control unit, thermoelements, electrovalve, heaters, fluid, temperature sensors, strain gauges, fasteners [2].

The disadvantage of this method is the high metal consumption of the under-rail base, large forces acting on the track, the need to dismantle the track when installing the device.

The advantage of the prototype is the thermal stresses arising in the details of statically indeterminate systems, with changes in the ambient temperature, due to the difference in the coefficients of linear expansion that can be used to fasten the rails. Simplicity of control due to insignificant heating from ambient temperature allows creating efforts commensurate with the strength capabilities of materials. Small dimensions, absence of moving links, insignificant costs for heating thermoelements (10-20 W) allow using the proposed invention in automatic control units to obtain high resistance forces.

The aim of the invention is to reduce metal consumption, simplify installation work during installation, expand the possibilities of application, automate the control of temperature and power movements, stress-strain state of rails and other parameters of the track superstructure due to artificial intelligence embedded in the program control unit.

1. A method of frictional compensation of movements of a continuous-welded rail track, including a block of compensators, thermoelements and a liquid with a large coefficient of linear and volumetric expansion, cradles, rails, a sleeper grid, floating side plates, fasteners, an electrovalve, a program control unit, characterized in that the rails fixed in the cradle, while screwing the bolts on one side, and on the other, the body of the compensation unit into the threaded bushings of the vertical posts of the cradles with a preliminary tightening torque of 300-1000 Nm, while creating the neck compression forces through floating elongated linings equal to the length of the rails, which are installed in sinuses on both sides, on both branches, create a friction force, prevent axial movement of the rails relative to the sleeper grid.

2. The method according to claim 1, characterized in that the friction forces opposing the axial movements of the rails are summed up through the long pads floating in the cradle, which cover 6-30 sleepers, and the opposing forces of resistance to the axial movement of the sleeper grid are summed up and increase in proportion to the amount sleepers on which expansion joint blocks are installed.

3. The method according to claim 2, characterized in that for automatic control of the displacements and stress-strain state of the rails, the friction forces from the preliminary tightening are summed up with the forces from the elongation of the thermoelements when the ambient temperature changes and from the fluid pressure in the cavity of the liquid expansion joint heating, increase the temperature of the compensator and the friction force up to complete pinching from axial displacements, and to reduce the resistance forces, on the command of the control room, the heating of the thermoelement is turned off, the pressure is released through the solenoid valve to the required value.

4. The method according to claim 1, characterized in that the frictional forces of resistance to the axial movements of the rails are created by the pressure of the plunger of the solid-state compensator block through the friction liners, on the elongated linings and on the neck of the rails, while doubling the number of sliding friction surfaces and the magnitude of the friction force in each cradle.

5. A device for implementing the method according to claim 1, including rails, lodgements on a sleeper grid, compensation blocks, fastening bolts, characterized in that the bushings of the vertical lodgment posts on both sides and the body of the friction compensation block are threaded to create a preliminary tightening, friction forces and fastening the rails when screwing them together.

6. The device according to claim 5, characterized in that it is equipped with a sleeper lattice, rails, lodgments fixed on both sides in the size of a track, floating long pads for the entire length of the rails, connecting 5-30 sleepers, with the help of which the friction forces on the rails and ballast forces on the sleepers, while providing joint resistance to axial movements.

Abbreviations used in the description of the invention:

BFK block of frictional compensation;

BRP continuous welded rail track;

BPU program control unit;

LHC automatic compensation unit

BCS block for compensation of butt gaps;

SSS stress-strain state of rails.

FIG. 1 shows a diagram, top view of the rail track.

FIG. 2 shows section AA.

The device for implementing the method consists of the following main parts: rail 1, sleeper grate 2, lodgements 3, elongated pads 4 (Fig. 1, 2) fastening bolts 5, friction liners 6, spring nut 7, screw 8, BFK 9, plunger 10 , solid-state compensator 11, stop 12, set of gaskets 13, heat-insulating gaskets 14, cuff 15, threaded plug 16, liquid compensator 17, temperature sensor 18, pressure sensor 19, BPU 20, cover 21, heater 22, liquid heater 23, gaskets 24 , butt pads 25 (Fig. 1), strain gauge 26, electrovalve 27.

The line of wires connecting with the BPU 20: temperature sensor 18, pressure sensor 19, heater 22, liquid heater 23, power grid, strain gauge 26, power grid 27, battery 28.

By means of the device, the method of frictional compensation of the rail track is carried out as follows. The BFK consists of a rail 1, a rail-and-sleep lattice 2 of lodgements 3 with elongated pads 4 placed in the bosoms equal to the length of the rails. The lodges are fixed to the sleepers in the track size with the fastening bolts 5 (Fig. 2). The fastening of rails 1 in the vertical posts of the lodgments 3 is carried out by screwing in screws 8 and the housing of the compensation unit 9 until they stop in the friction liners 6 (Fig. 2), elongated linings 4 and in the neck of the rail 1. To simplify fastening of the rails, their base is cut to the width of the head, providing free lowering into cradles 3.

The tightening of threaded connections is carried out by analogy with the joints of serial lines, with a preliminary tightening torque of 300-1000 Nm. In this case, due to the tightening torque, axial friction forces are created that act directly on the rail necks. The maximum axial forces in the rails can reach 15000 KN, which can cause track ejection or destruction [3, 4].

The gap Δf on both sides installed on the rail and sleepers is necessary to control the displacement of the elongated linings relative to the sleepers and rails. When sampling the gap, the resistance of the sleeper grid with expansion joint blocks will increase due to the increase in the resistance of the adjacent section of the rails. When the rolling stock moves back, the gap is restored.

The sleeper lattice, equipped with elongated strips 4 for the entire length of the rails, installed in the axles, ensures the summation of the resistance forces from the ballast side against axial displacement.

With large lengths of continuous welded strings, to ensure the resistance of the RSHR to shear forces, it is possible to sequentially install several BFCs, connected to each other along both threads by butt pads 25, taking into account the linear and ballast resistance at each section of the track. The BFK is assembled at the factory on rails of standard length, it is a single whole of two rails in cradles fixed on sleepers assembled with automatic control elements.

For damping shock loads, noise, regulation of the position of the rails in the size of the track, friction forces between the rail and sleepers, installation on the level of the rolling surface is carried out with a set of elastic and metal spacers 24 (Fig. 2).

Installation of friction bushings 6 fixed relatively to elongated linings and cradles 3 provides a fourfold increase in friction forces during axial tightening of screws 8 and the housing of the compensation unit 9 arising between frictional 6 and elongated linings 4 with rail 1.

To eliminate the axial movement of the elongated linings 4, the friction surface of the liners 6 from the side of the liners are treated by plasma spraying of SiO and WC carbides. The machining increases the frictional forces when the linings are displaced in the axial direction.

The amount of displacement and friction force on the elongated pads, in addition, is regulated by the selection of the coefficient of friction of the pads 24.

When assembling the compensation unit 9, to reduce heat losses, heat-insulating gaskets 14 are installed around the entire perimeter of the solid-state compensator 11.

A set of shims 13, when installing the stop 12, and screwing in the plug 16 and screws 8, ensure the elimination of the gap and interference between the plunger 10 and the friction liners 6, while maintaining a sufficient gap Δt within 2-3 mm. If it is necessary to create additional axial force by the pressure of the plunger 10 on the friction liners 6 when the compensation unit is assembled, they are provided by gaskets 13 when tightening the plug 16. The gap Δt is necessary to ensure clamping forces at positive and negative temperatures.

When the liquid freezes, its volume increases by 8% of the original. Sealing of leaks of the liquid compensator 17 is carried out by a continuous cuff 15. Pressure sensor 19, temperature sensor 18, electrovalve 27, heaters 22 and 23 and strain gauge 26 are connected to the control unit, which are switched on and off according to the program in the unit.

When the ambient temperature changes due to the difference in the coefficients of linear expansion of the materials of the solid-state compensator 11, the plunger 10 and the housing of the compensation unit 9, a significant difference in deformation is formed, which is accompanied by the formation of forces compressing the rail and friction forces that prevent the movement of the rail threads in the axial direction. The reaction from the longitudinal tightening force of the screws 8, the frictional compensation unit 11, from the difference in temperature elongations of the mating parts of the compensators is perceived by the vertical supports of the lodgements.

Friction forces are used for automatic control of axial displacements and SSS of rails. With an increase in the length of continuous filaments, temperature, the stress-strain state of rails approaches the maximum permissible state that can cause ejection or destruction.

The load cell gives a signal to turn off the jamming and transfers excessive movements to the pointed rails of the LHC of displacements [3]. The LHC provides due to the movement of pointed rails in the axial direction, the edges of which are conjugated with the edges of the pointed platform movable in the transverse direction, due to spring pressure.

The automatic control system with the help of BPU 20 against the background of natural temperatures ensures that the heating of thermoelements is switched on and off in order to preserve the permissible temperature movements, the strength of rails and other parts, the stability of the track, and the elimination of emissions and thefts. The criterion for the operability of the rails at a controlled voltage level is the stability of the track, which can be controlled in the automatic mode by shifting the rail clamping temperature to the positive or negative region, depending on the annual displacement of its maximum relative to the zero value.

The load cell 26 on the rails provides information about the stress state, according to which, according to the program, the BPU 20 regulates the friction force.

When the limit values are reached, for example, at negative temperatures, posing a danger to a break in the rails, at the signal of the ambient temperature sensor 18 and the strain gauge 26, the BPU 20 switches on the short-term heating of the frozen liquid 17 by the heater 23. The heating provides temporary melting of the liquid, reduces the tensile stresses in the rails to safe level in the range from 5% to 10% of their limit value with subsequent shutdown. The resulting emergency movements are compensated by the method provided by the patent [3].

To save energy at a long seasonal constant temperature, it is possible to supply pressure through the solenoid valve 19 from the plunger pump.

When using the proposed invention, it becomes possible to accumulate a significant part of the deformation in separate specially laid sections between the BPC displacements due to pinching at certain temperatures to maintain the required level of deformation and stresses in the rails, reducing the limiting values that cause ejection or destruction.

The increase, decrease in longitudinal friction forces, obtained by heating a solid-state compensator, freezing a liquid, or changing pressure, provides a unique ease of automatic control of path parameters.

The use for automatic control of mechanisms of a statically indeterminate system, the driving force of which are internal stresses arising from temperature changes, allows you to automate the control of path parameters. The use of the proposed invention in combination with previously obtained patents aimed at compensating for temperature deformations makes it possible to completely eliminate their effect on strength, durability and stability and reduce to a minimum the amount of regulated work, increase the efficiency and safety of railway transport operation.

Calculation of power and geometrical parameters show high relative performance of the structure, low power consumption, high compactness, simplicity and reliability of the implementation of the method, against the background of large required efforts.

где α=11,8⋅10⁶, Δt=60°С,

F=95 см², n=1,3 запас прочности в рельсах.Initial data for calculation: yield point of rail steel σ _t = 750 MPa; E-modulus of elasticity 2.1⋅10 ⁶ , thermal elongation of a kilometer lash

where α = 11.8⋅10 ⁶ , Δt = 60 ° C,

F = 95 cm ² , n = 1.3 safety factor in rails.

An approximate assessment of the stress state, the magnitude of displacement and deformation was carried out for rigidly clamped rail ends at a temperature of ± 60 ° C. The temperature value is selected from the condition of ensuring the safe operation of the track.

1. At + 60 ° C, the free movement of a kilometer continuous section of the track is 708 mm. The stresses in the rails when the specified deformation is pinched will be:

Allowable rail stresses:

[σ] =. 750 / 1.3 = 576 MPa (5760 kg / cm ² ),

Axial force at maximum temperatures and ultimate stresses on one lash reaches:

P = [σ] F = 5760 95 = 547200 kg (547 t),

where F = 95 cm ² is the cross-sectional area of the P75 rail.

These efforts must be compensated for by the frictional compensation of the rail movements.

To overcome the maximum forces in the rails from temperature displacements, the total compression forces of the rail necks developed by the compensators will be required:

ΣР _к = Р / f = 547 / 0.4 = 1367.5 t (13750 Kn),

where f is the coefficient of friction equal to 0.4 [6]. which can be increased by plasma spraying of inserts with carbides WC, SiO and other known methods to 0.7 and reduce the forces to 781 Kn.

диаметре 120 мм; температуре нагрева ΔТ=60°С его удлинение составитWith the dimensions of the solid-state compensator 11:

diameter 120 mm; heating temperature ΔТ = 60 ° С, its elongation will be

необходимо увеличить длину компенсатора 11.where α = 7.9 × 10 ^{-5 is the} coefficient of linear expansion of the material of the solid-state expansion joint. If it is necessary to increase the value

it is necessary to increase the length of the expansion joint 11.

The axial force Pk, developed by one solid-state compensator 11, when extinguishing its own thermal elongation of 0.0945 cm will be:

where E = 217 10 ³ is the modulus of elasticity of the material of the solid-state compensator, F = 0.785 D ² = 113 cm ² , the cross-sectional area of the solid-state compensator.

The total force of lateral compression of the rail by one frictional compensation unit will be:

ΣР = Р _к + Р _б = 1226 + 100 = 1320 Kn (132 t) in each lodgement

P _b = T⋅d⋅tg (β + ϕ) / 2 ~ 10 t.

Here R _b is the axial force with controlled tightening of the threaded connection 8. T is the average value of the torque (taken to be 500 Nm).

The maximum friction force created in the axial direction by the pressure of the plunger of the expansion joint block through the friction liner 6, the elongated strip 4 on the rail neck through 4 sliding surfaces in one cradle, with a friction coefficient of 0.4 [6] will be:

Ft = ΣP⋅f n = 1320⋅4 0.4 = 2112 Kn (211 t),

where f is the coefficient of friction, n is the number of friction surfaces between elongated linings, friction liners and the rail.

To compensate for maximum stresses and displacements at maximum temperatures, you will need to install:

N = ΣP _to / F _t = 13280/2112 = 6.5 pieces

Installation of 14 blocks BFK 9 compensation on two branches will compensate for temperature movements up to the pinching of the rails in any extreme cases.

2. Calculation of the pressure of the liquid 17 in the cavity of the stop 12, which provides the possibility of creating constant forces of frictional braking.

The force from the side of the stop 12 from the fluid pressure: P _l = S⋅P, where S is the area of a hollow piston with a diameter of 120 mm, S = 0.785⋅D ² = 113 cm ² , P is a fluid pressure equal to 250 kg / cm ² :

P _w = 113 250 = 28 250 kg = 282.5 Kn (28.5 t).

Considering that when the rails are fastened with threaded connections, a rail compression force P _b = 100 Kn (10 t) is created. The total force of compression from pressure and tightening will be:

P = 100 + 282.5 ~ 382 KN (38.5 t).

The friction force in the axial direction from pressure, from tightening and from the elongation of thermoelement 11 at the actual ambient temperature (taking into account the difference between the rail fastening temperature and the actual one (the fourth part of the maximum heating temperature 60/4 = 15C ° is accepted) will be:

Ft = n⋅f (P _b + 0.25 Ft + P _g ) = 4⋅0.4⋅ (100 + 0.25 2121 + 282) = 1517 Kn (151 t).

To compensate for displacements at the level of pinching for long periods and extreme temperatures in order to save energy when a pressure of 250 kg / cm ² is applied, the frictional force developed by 18 compensators on both branches is sufficient, which will ensure energy savings and installation in places where there is no electricity.

N = ΣP _k / F _t = 13750/1517 = 9

3. Calculation of the required volume of fluid for frictional braking of the rail.

When a liquid (for example, water) freezes, its volume increases by 8%. The calculation of the required volume is based on the condition of ensuring the equality of displacements and efforts developed by the BFC 9 when the temperature changes to -60 ° C.

что необходимо обеспечить за счет прокладок 15 и 24 при сборке БФК с натягом всей размерной цепи при затяжке резьбовых соединений (винтом 8, БФК и заглушкой 16),The maximum displacement of the thermoelement plunger at the specified temperature change shall be

what must be ensured by gaskets 15 and 24 when assembling the BFK with an interference fit of the entire dimensional chain when tightening the threaded connections (screw 8, BFK and plug 16),

где S площадь поршня S=0,785 D²=113 см².With a cavity diameter of 120 mm and a displacement equal to the displacement of the plunger from the elongation of the solid-state expansion joint, the required increase in the volume of liquid will be

where S is the area of the piston S = 0.785 D ² = 113 cm ² .

ΔV = 113 0.1 = 11.3 cm ³ , which equates to the required increase in volume by 8% when the liquid freezes. Hence, from the proportion, the required volume of liquid is V = ~ 400 cm ³ . The linear dimension of the stop cavity 12, which ensures the placement of the required volume:

L = V / S = 400/113 = 3.53 cm.

The length of the cylindrical part of the stop 12, which is filled with liquid, is 4 cm.

The performed calculations of the power and geometric parameters of the device according to the method show high relative performance of the design, the possibility of long-term operation without power consumption, high compactness, simplicity and reliability of the implementation of the method, against the background of large required efforts.

Comparative analysis of the properties of the proposed method and the prototype shows that the method is distinguished by the possibility of simple and reliable automatic control of track parameters, such as the resistance of the RSHR, the stress-strain state of the rails, to preserve the required level of temperature stresses and displacements of different signs. Provides control of the temperature and the level of frictional pinching, allows you to shift the temperature of fastening the rail in the positive or negative region, depending on the seasonal displacement of the maximum relative to zero, which meets the criterion of the invention "Novelty".

The natural change in ambient temperature is used as the driving force of the automation actuators, which ensures simplicity of design, the absence of expensive executive mechanisms, low power consumption, high reliability and safety of ensuring the functions performed, which meets the criterion of the invention "Industrial applicability".

Varying geometric dimensions, pressure, heating temperature, pinching can expand the scope of the proposed invention.

The operation of rail lines is one of the most complex and expensive technical problems associated with constant monitoring and maintenance of the voltage level in the rails, seasonal setting and replacement of equalizing spans, monitoring of linear and lateral track displacements, prevention of emissions, theft, anticipation of a constant threat of an emergency. The listed scope of work is associated with the maintenance of a huge staff of highly qualified service personnel. The maintenance cost of the track superstructure is 40% of the total cost of its maintenance.

Using the proposed method allows you to control the main parameters of the track superstructure, reduces the likelihood of anomalous manifestations and eliminates an emergency.

Literature

1. Patent No. 2679849 C1, IPC E01B 11/32, 11/27/2017.

2. Patent No. 2686597 C1, IPC Е01В 11/32. 06/22/2018.

3. Patent No. 2685491 C1, IPC Е01В 11/32 06/22/2018.

4. Continuous path. M .: "Transport", 2000.

5. Instruction on the current maintenance of the railway track M .: "Transport", 2000.

6. Kragelsky I.V., Vinogradova I.E. Coefficients of friction. Moscow, 1962.

Claims (6)

1. A method of frictional compensation of displacements of a continuous-welded rail track, including a block of compensators, thermoelements and a liquid with a large coefficient of linear and volumetric expansion, cradles, rails, a sleeper grid, floating side plates, fasteners, an electrovalve, a program control unit (hereinafter referred to as a control unit), characterized in that the rails are fixed in the cradle, while on one side the bolts are screwed, and on the other, the body of the compensation unit into the threaded bushings of the vertical posts of the cradle with a pre-tightening torque of 300-1000 Nm, while the neck compression forces are created through floating elongated linings equal to the length of the rails, which are installed in the sinuses on both sides, on both branches, create a friction force at the same time, prevent the axial movement of the rails relative to the sleeper grid. 2. The method according to claim 1, characterized in that the friction forces counteracting axial displacements are summed up through long pads floating in the cradle, which cover 6-30 sleepers, and the opposing forces of resistance to the axial movement of the sleeper lattice are summed up and increase in proportion to the number of sleepers on which the expansion joint blocks are installed. 3. The method according to claim 2, characterized in that for automatic control of the displacements and the stress-strain state of the rails, the friction forces from the preliminary tightening are summed up with the forces from the elongation of the thermoelements when the ambient temperature changes and the pressure of the liquid in the cavity of the liquid compensator, and in case of a shortage which, at the command of the BPU, turn on the heating, increase the temperature of the compensator and the friction force up to full pinching from axial displacements, and to reduce the resistance forces at the command of the BPU, the heating of the thermoelement is turned off, the pressure is released through the solenoid valve to the required value. 4. The method according to claim 1, characterized in that the frictional forces of resistance to the axial movements of the rails are created by the pressure of the plunger of the solid-state compensator block through the friction liners, on the elongated linings and on the rail neck, while the number of sliding friction surfaces and the magnitude of the friction force in each cradle are doubled ... 5. A device for implementing the method according to claim 1, including rails, lodgements on a sleeper grid, compensation blocks, fixing bolts, characterized in that the bushings of the vertical lodgment posts on both sides and the body of the friction compensation block are threaded to create a pre-tightening force friction and fastening of rails when screwing them together. 6. The device according to claim 5, characterized in that it is equipped with a sleeper grid, rails, lodgments fixed on both sides in the size of a track, floating long linings for the entire length of the rails, connecting 5-30 sleepers, with the help of which the friction forces on the rails and ballast forces on the sleepers, while providing joint resistance to axial movements.

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