4.1.23. Damages of tyres because of errors at mounting (assembly damages)

Fig. 4.26. The scheme of installation of the tyre on a disk: 1 – хамп (double хамп H 2); 2 – onboard закраина rims; 3 – an internal shoulder of a rim (e.g. a conic shelf); 4 – a rim; 5 – a disk; 6 – a cavity; 7 – an external shoulder of a rim (e.g. a conic shelf)

Modern radial tyres for cars are mounted exclusively on safe disks. Their rims have on shoulders an eminence 1 on all circle (fig. 4.26).

Хамп protects the tyre at driving with low pressure of air in it from соскальзывания from a rim shoulder.

At a tyre rating can happen that the tyre board not completely will move through external хамп rims.

In this case there is a danger of an excessive extension of the core of a board at too high pressure therefore its steel threads will be broken off partially or completely. Rupture of the core of a board is imperceptible outside.

ATTENTION Tyres with the damaged core of a board leaky sit on a disk rim. Such tyres are extremely unsafe at operation. Besides, there is a danger that the torn core of a board in movement will be broken off completely, and the tyre will suddenly blow up. At rupture of the core of a board at a rating of the tyre the skeleton also collapses.

Fig. 4.27. The tyre with the broken off core

In drawing 4.27 the tyre with the broken off core and the destroyed skeleton as a result of an excessive stretching is represented at installation.

Damages of a board because of erroneous or wrong mounting on шиномонтажном the stand

Following errors at mounting can lead to serious damages of tyres:

– If at закатке the top board on шиномонтажном the stand the opposite board of the tyre not completely lies in a cavity;

– If the assembly head has incorrectly been adjusted;

– If the edge of an assembly roller slides on an onboard roller;

– In the presence of the worn out or sharp directing rollers.

Fig. 4.28. Tyres with a board cut

In such cases the board which is under a high voltage, can be made an incision, cut and-or jammed to a core wire (fig. 4.28).

Often in a damage zone traces of the beginning and the end of contact to a directing roller are visible.

THE NOTE Essentially it is necessary to grease both boards of the tyre and rim shoulders шиномонтажной with paste. If damages at installation remain not noticed, there is a danger of destruction of the tyre at its further operation. Never mount tyres without шиномонтажной pastes. Do not pump up an explosive rating from above 3 bar. Do not pump up the tyre from above 4 bar. In the end of mounting lower pressure of air in the tyre to the ordered value.