| 摘要 |
<p>A weight sensing apparatus particularly, but not exclusively, for weighing tracked vehicles, comprises a beam (20) supported on first and second support means (23,24), at least one strain gauge (25,26) being positioned between the support means (23,24) and being spaced from the support means and an applied load (L), by a distance equal to, or closer than, a distance d max., where d max. is the thickness or maximum thickness of the beam (20) in the direction in which the load is applied. In addition the strain gauge must not be positioned closer to the supports or applied load than 0.35 d max. Each strain gauge is in the form of a strain gauge rosette having two strain elements G2,G8 and G1,G7 e.g. resistance wire elements, arranged transverse to one another, to the axis A of the rail and to the direction of the applied load. The gauge elements sense shear strains imposed by load L and are preferably mounted midway between the top and bottom of the rail on one side thereof. An identical arrangement of aligned strain gauges may be provided on the other side of the rail and all the elements thereof connected in a bridge circuit to compensate for twisting of the rail. The output of the bridge is fed to a controller where the wheel load is computed. The apparatus may be used to sense the direction of movement of the vehicle, the speed of the vehicle and the distance between axles.</p> |
