Vehicle spring suspension has two basic tasks. In safety terms, it achieves as stable contact of the tyre with the road as possible. The produced adherence pressure is very important for the transmission of braking forces and driving forces from the wheel onto the road, thus ensuring maximum rideability. In terms of comfort, it prevents the transmission of vibrations and forces onto the body and passengers whilst driving over uneven road surfaces. The increase in comfort thus decreases rider's fatigue during a longer ride. The relevant structural elements of the motorcycle have to be precisely adjusted as both functions are in contradiction to one another. Although with increasing softness of suspension riding comfort increases, the adherence pressure decreases and the wheel bounces more from the road surface. It is therefore evident that a change of conditions of shock absorbers caused by their wear-out, breakdown etc. is a factor which significantly impacts safety; therefore the conditions should be observed.
In technical practice, a visual check (damage, leaking of sealing liquid, etc.) and an acoustic check (non-standard functioning) are used. However, these procedures cannot be quantified well, and they are unsatisfactory from the professional point of view. Moreover, problems occurring can be detected too late, which may have a considerable impact on the safety of all those involved in traffic.
The precise diagnostics of shock absorbers require testing with special equipment, in which the shock absorber must be removed from the vehicle and placed in the testing equipment. Disassembly and re-assembly is labour-intensive and, as a consequence, time- and financially consuming. In the effort to resolve these issues, a number of new, so-called non-assembly testing methods, have appeared. However, they have been developed for cars and they are not suitable for use on motorcycles.
Figure 1: Schematic illustration of the method
The issue of non-assembly testing of axles has been resolved by a renowned scientist of the Institute of Machine and Industrial Design at BUT, Doc.Ing. Ivan Mazůrek, CSc., who has been dealing with the issue of diagnostics of axle suspension for many years and has several patents in this field. Docent Mazůrek has presented an innovative, verified method of non-assembly testing of the absorbing properties of axles of single-track vehicles. The principle of testing is very simple and lies in an analysis of the tail of non-suspended materials whilst riding over a defined barrier at a slow speed (Figure 1, Pos. 1). Whilst in motion, the move of non-suspended mass is recorded, and the condition of the axle suspension can be determined from the duration of the mass's tail. Measuring is performed with sensors positioned in both the front and rear axles of the vehicle (2), which are interconnected with a converter that is connected via wireless to a computer equipped with the appropriate software.
The developed method is considerably more time- and cost-effective than other existing procedures and, thus, it is a significant advantage in improving motorcyclists’ safety. The method is protected with a patent; the respective equipment is protected by means of a utility design.
Figure 2: The sensor installed on the rear fork
Source of initial picture: stockvault.net
Source of the pictures in the text: the archives of the patent authors
