4.1.23. Damages of tyres because of errors at mounting (assembly damages)
The board core was broke off at a tyre rating
|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.
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.
The tyre with the broken off core of a board and the destroyed skeleton
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.
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.
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.