The present invention refers to a system for assembling a high-pressure fluid tube on a tubular pin, which is part of a fitting element provided to be used in particular on motorcycles and motor-vehicles, for example for the production of pipes intended for manufacturing braking circuits or other circuits, in which high-pressure oil or other fluids flow.
In particular, the invention relates to a system for assembling a high-pressure fluid tube of the kind comprising a first inner layer made of plastic, a second layer made of a steel plait or other suitable material such as fibers or the like, a third coating layer, if any, made, for instance, of plastic material and a bush made of steel, alloy or other material, fitted into an end of the said tube, this tube being fitted on the pin and locked by crimping of the metallic bush.
In order to avoid any oil leakage, which may occur in the vehicle systems made by the known methods, the invention teaches to create, in the pin where the tube is fitted into, an annular groove assigned to lodge an O-ring type gasket.
In this groove, after crimping of the metallic bush, an end of the bush is overlaid, until the end presses and distorts the gasket, which is thus locked against the grooves sides, thus preventing any seepage.
The system for assembling according to the invention enables to create, without the use of particularly complex and expensive equipment or systems, tube fittings for high-pressure fluid, which guarantee a total tightness and, as a result of it, are able to pass the strict tests provided for by the regulations on this subject.
As it is known, most of vehicles equipped, provided with circuits that bring fluids under pressure, comprise also parts made of hoses, provided at the ends with fittings elements to be coupled with corresponding elements fitted on the vehicle.
The said hoses comprise, in general, three of more layers: an inner layer made of plastic, an intermediate layer consisting of a steel plait able to resist internal high pressure, and a third layer, a coating layer, made of plastic.
At the ends, on the hoses, metal bushes are fitted into, generally made of steel, which are then locked by crimping, to lock the hose on the pin.
On the other hand, it often happens that due to the high pressure, the fluid circulating in the hose, even if in a small amount, seeps between the hose internal and external wall of the pin, thus affecting, over the time, the correct operation of the system, with the risk of creating hazardous situations.
The sector feels therefore the need to be provided with means capable of assembling a high-pressure fluid tube on a pin, which is a part of a fitting, thus guaranteeing the system to be perfectly sealed.