Know How

AXTONE Group is an expert in impact energy absorption for all types of rail vehicles. The buffers and Crash elements offered by AXTONE assure the safety of all the vehicles in railway transport, as well as their passengers and cargo.

Crash technology is a method of controlled transfer and absorption of great impact energy in the high-speed collision conditions. It was developed to increase the level of passive safety in railway transport. Our R&D Department designs individual solutions, creates passive protection of vehicles systems, whose quality assures stable and reliable functioning.

Why AXTONE Crash Technology?
  • Safety of all the passengers, goods and vehicles in railway transport;
  • Certainty of professional service;
  • Guarantee of reliable functioning supported by over two hundred fiels tests;
  • The highest quality of products confirmed by certificates;
  • High qualifications and great experience of the Engineer team, ready to meet individual requirementsof the Customer.

Peeling technology

Innovative, patented by AXTONE Crash technology means that the impact energy is absorbed through permanent deformation of a strip of steel cut from the buffer body.

During a collision, the outer surface of the buffer box is sheared by the shearing blades. The level of absorbed energy depends on the size and section surface area of the shearing band, which enables a wide-ranged adjustment of crash parameters to specific applications.



Folding technology

Energy absorption is controlled by plastic deformation of the buffer plunger with specially shaped sleeve walls. The level of the absorbed energy depends on the deformation forces. By changing the shape of the sleeve a broad range of controlled parameters is obtained that can be modified in the Crash buffers in accordance with the individual requirements of the customers.



Main advantages of Crash Technology

  • Stability and repeatability of deformation force;
  • Reliability of functioning during axial collisions, with great displacement of the axis and at rail curve, confirmed in simulations and actual collisions;
  • Low mass crash absorber;
  • Simplicity and wide range of changes of average deformation force and absorbed energy;
  • Installation of the crash absorber in front of the buffer beam (if there is no room behind the beam) in the same way like with standard buffers or with use the room behind the beam;
  • Possibility of using different shock absorbing systems of A and C category;
  • Very large irreversible buffer strokes are available;

Crash tests:

KAMAXIL® is a silicones elastomer, which is formed as homogenous composition of methyl-, phenyl-, borosiloxane polymers with addition of fillers and lubricating mediums. KAMAXIL® is a plastic, compressible substance with high viscosity. In static condition it behaves like a plastic substance, but in dynamic condition it is characterized by very high modulus of elasticity and capability of storage and dissipation of mechanical energy, damping of vibration, strokes and many others type of loads.

The main properties of KAMAXIL®:

  1. Compressibility – ability to change volume under pressure – this allows for absorber to behave like spring.
  2. Dissipation of energy – internal friction between polymer chains and partitions of filler allow to absorb energy of loads by absorber.
  3. Thermal resistance – chemical structure allows to keep the fluid state of polymer till -60°C – due to this property absorbers may be used in areas where temperatures may reach such limits. Our absorbers can operate from -60°C up to +50°C.

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Applications:

  • Standard side buffers according to UIC EN 15551;
  • Central couplers for freight wagons e.g. SA3 according to GOST;
  • Automatic and semi-automatic couplers for passenger coaches;
  • Industrial applications in iron works, rolling mills, etc.;
  • Military applications.

AXTONE is a producer of EuroPad® - elastic pads made from solid elastomer. Elastomer pads are produced from high performance thermoplastic polymer. It ensures excellent work parameters, wide range of work temperature (-60 ¸ +50°C), long life cycle and reliability at work. AXTONE produces different type of elastomer pads depending on application. Elastomer pads are used in buffers, draw gears and shock absorbing devices for railway market.

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EuroPad® depending on size and application are produced by injection moulding or extrusion moulding. For injection moulding technology are used injection moulding machines made by KraussMaffei company. For extrusion moulding technology a special production line designed and produced by AXTONE is used.

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EuroPad ® - AXTONE potential :

  • wide knowledge and long experience in design and production;
  • wide range of products;
  • in-house laboratory equipped with hydraulic presses with maximal force of 2500 kN;
  • possibility of creating new pads for new applications;
  • adjusting existing pads for new applications;
  • high production capacity;
  • modern production equipment;
  • high product’s quality confirmed by certificates;

Applications:

  • Side buffers according to EN 15551;
  • Central couplers for freight wagons e.g. SA3 according to GOST;
  • Draw gears according to EN 15556;
  • Secondary vertical suspensions;
  • Solid elastomer static characteristic.
 

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Depending on the performance specifications, our buffers can also be equipped with hydraulic shock absorbers – Combigard ®.

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Features:
  • Combigard ® is an oil hydraulic damper with several possible „combinations“ of pre springs, you can select the best characteristic solution for your application by keeping the min. capacity of 70 kJ;
  • Temperature range -40°C to +50°C;
  • Force ranges according to EN 15551
  • Stroke up to 150 mm.

Applications:

  • Standard side buffers according to UIC EN 15551;
  • CAT C Buffers > 70 kJ energy absorbing device;
  • CAT L Buffers , long stroke, 150 mm

AXTONE Group is the only manufacturer to use hot extruded buffer housings manufactured in one piece. The absence of any welded connections guarantees the highest quality and exceptional durability of our products. During this forging process, the raw material is heated to a temperature of only 1250°C. Herewith it is guaranteed that no air or dust will enter and degrade the material properties.

Hot-extruded-buffer-housings

Ring-Springs

Production of rings used for friction springs which meet the requirements of the chart UIC 827-2 takes place in the Czech company owned by the Group. The springs are manufactured in a wide range of various diameters from 80 to 400 mm. The rings are used in friction springs of Ringfeder type applied in buffers, tractive apparatuses, pull rod bars and automatic couplers.

Features:

  • Hot formed, highest quality materials;
  • Various shapes possible;
  • Linear characteristic;
  • Safe against overloading;
  • Big damping due to friction;
  • Characteristic independent of the speed;
  • Characteristic independent of the temperature;
  • Proven in rail applications.

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Basic technical dates of friction springs:
F Spring terminal force d1 Inner diameter
Se Stroke for 1 element b/2 Half ring width
We Spring work for 1 element D2 Guide outer diameter
he Height of 1 element d2 Guide inner diameter
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Example of spring calculation

  • This spring consists of 4 elements type 19600:
  • End force = 600 kN
  • Stroke = 4 x 4,4 (Se ) = 17,6 mm
  • Spring work (Absorbed energy) = 4 x 1300 (We) = 5200 J
  • Spring length = 4 x 23,4 (he) = 93,6 mm

By adding additional elements, we increase the stroke (length of the spring), the absorbed energy (spring work) but the end force will remain the same. End force still 600 kN.

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During the operation of the friction spring two thirds of the input energy is dissipated as frictional heat. The recoil force at any point on the diagram is approximately equal 1 / 3 of the relative compressive force F. The capacity of the spring is represented by the total area shown below the load curve.

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Friction springs are generally designed to „block”, so it is therefore ensured that the admissible stresses cannot be exceeded and the friction spring will not be damaged.

Applications:

  • Buffers;
  • Draw gears;
  • Draw bars;
  • (Semi) automatic couplers .

 Coil springs

AXTONE Group manufactures coil springs using rods from 2 mm up to 80 mm diameter, up to 12 000 mm length and the springs have a maximum overall diameter of up to 450 mm.

Whether twisting left or right, rolled out or ground directly from the rod, with linear or progressive characteristic – nothing is impossible.

A vast multitude of thousands of different types meets the requirements of a wide range of applications, with new additions every day. Our springs are dedicated to railway sector - for locomotives, freights wagons (e.g, bogieY25 and others), rail carriages, railcars, trams or high-speed trains such as ICE and TGV – AXTONE provides the right springs for all kind of rail vehicles. Additional we offer spring solution for mining industry, construction machinery, playground equipment, power plants, agricultural machinery and springs using for vibration isolation.

Key features of our products:

  • AXTONE coil springs are made of high-strength spring steels from selected suppliers
  • AXTONE coil springs are produced with state-of the art equipment and processes
  • AXTONE coil springs stand for high quality, long lifetime and high reliability
 

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Parabolic and trapezoidal springs

Trapezoidal springs and the modern parabolic springs, made by AXTONE, are well proven spring elements for freights wagons all over Europe and beyond – in many dimensions and special designs!

If you should ever get the impression that there is nothing in our extensive range that meets your special needs, we will react – as flexible as our springs – with a customized solution, made to measure for your vehicle.

Key features of our products:

  • AXTONE leaf springs are only made of high-strength oil-hardened spring steels
  • AXTONE leaf springs stand for high quality, long lifetime and high reliability
  • AXTONE leaf springs can be adjusted to customer´s demand due to our development capabilities and experience

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TKS springs

Higher requirements regarding speed and wheel set load of railway vehicles lead to the need of suspension springs with progressive spring characteristic.

In most cases spring sets are used consisting of two linear coil springs which are different in length, the inner spring usually being shorter and therefore starting to act later when a certain spring load is reached. The disadvantage of this solution lies in the fact that the inner spring is not loaded up to the contact point and can thus oscillate freely in the outer spring, damages to the paint and an unpleasant rise of the noise level being the consequence.

An alternative solution is the conventional coil spring with constant wire diameter, which achieves its progressive characteristic by means of variable distances between the coils. Due to the constant wire diameter the spring length increases, which often make the use in railway vehicles more difficult or even impossible.

The AXTONE TKS® spring with taper rolled wire cross section in the progressively acting coils, offers the optimum solution! The wire of the progressive coil zones is tapper rolled in such a way that the width of the resulting cross section corresponds to the wire diameter of the spring and the thickness is adapted to the respective stress.

Advantages are:

  • Progressive spring characteristic
  • Spring with cylindrical form with constant inner and outer diameter
  • Shorter in length compared to conventional progressive coil springs
  • Lighter in weight than comparable progressive coil springs

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Torsion bars

Torsion bars are spring elements used in railway vehicles – usually in bogies with air suspension in the secondary suspension – in order to control the roll angle of the vehicle, the stiffness of the air springs being rather low. Torsion bars can also be necessary in bogies with coil springs as secondary suspension, if those springs also have a low stiffness or are placed closer to the bogie center.

Torsion bars are in principle U-shaped. The ends of the U are connected to the car body with links, while the back (torsion part) is connected with the bogie frame by means of rubber bearings. During rolling of the car, the back (torsion part) is twisted due to the different movements of the arms and links. This results in a torsional moment, which tries to bring the car body back to the neutral position and so limits the roll angle.

Torsion bars are either assembled from 3 pieces (one back [torsion part] and two forged or casted arms) or bended from one bar. The back (torsion part) of the assembled version is made from round material. In the bearing or connection areas the bar diameter usually has to be increased by forging. The connection between arms and torsion part is made either by shrinking or by splines. As the torsion part is highly stressed, the material has to be heat treated and shot peened like coil springs. The bended version is made from one round bar, there is a bending radius between each arm and the torsion part. The ends of these torsion bars usually have to be forged to make the connection to the links by rubber bearings or similar connectors. These bended torsion bars also have to be heat treated and shot peened like coil springs.

There are no standard parts, the shape of the torsion bars being individually adjusted to the respective requirements regarding dimensions and space available in the bogie.

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Research potential

Long-standing experience and scientific-technical potential of the Research&Development Department enables AXTONE Group to cooperate products with the leading manufacturers of rolling stock in the development of customized products. As a result, AXTONE products are utilized in the most modern and innovative rail-vehicles in the world. AXTONE, being the leading manufacturer of the rolling stock, provides the Crash elements, buffers with the Crash module and centre coupling shock absorbers for many companies worldwide.

Software

Cooperation with the rolling stock engineers and designers from all over the world, obliges our Research&Development Department to use the latest software versions. To design innovative solutions, AXTONE Research&Development Department uses the following applications:

  • Pro ENGINEER ver.5 – a program with full product design and product technology functionality i.e. CAD, CAM, CAE, PDM and PDS. It covers everything from a concept, through design, construction, range of analyses, up to manufacturing technology, 2D documentation and CNC machine support.
  • AutoCAD – a CAD program aimed especially at 2D designing.
  • ANSYS 8.0 – a program for supporting engineering calculations, using Finite Element Method (FEM).

AXTONE Group owns Schenck and Instron research stations with force range up to 3000 kN, meeting the UIC requirements for velocity; and fast actuators of velocity up to 5 m/s and of nominal force of 40 kN. The products can be examined both in the path or force control mode.

Parameters of actuators:

Fn = 3000 kN V max = 12 mm/s stroke 200 mm
Fn = 1600 kN V max = 50 mm/s stroke 250 mm
Fn = 100 kN V max = 0.3 m/s stroke 100 mm
Fn = 40 kN V max = 5 m/s stroke 200 mm

Our researches entail:

  1. Registering the static characteristics of objects in temperatures between -70°C and +60°C.
  2. Examining product durability in temperatures between -70°C and +60°C.
  3. Examining products durability along with registering examination process.
  4. Examining products in both load axes (X and Y).
  5. Examining the parameters of materials durability in relation to tearing off and squeezing.
  6. Examining the chemical composition of low-alloyed steel, chrome-nickel steel and cast iron.
  7. Registering the operation of buffers, pull-collide apparatus and train apparatus used, in the railway sector.

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