METHOD FOR WEIGHING

Abstract: Method for weighing a load that is located on the platform of a lorry, which is tiltable around at least two mutually parallel revolving axles and which is provided with at least one hydraulic cylinder, in which system of pressure agent a pressure indicating device as a pressure gauge is arranged on a suitable place, by which the platform is first lifted around the first revolving axle after which the pressure is indicated on the pressure gauge, and by which the platform is lifted around a second revolving axle and the pressure is indicated, and that the indicated results are mathematically treated by the formula (I), <IMAGE>

Description: METHOD FOR WEIGHING The present invention is concerning a method for de¬ termination of the weight of loads on lorrys particularly on such which are provided with a platform that is tiltable around at least two mutually parallel revolving axles, by which the devices for carrying out the method are of the most simple kind. The princip of the method consist in indicating the pressure of a fluid in one or several hydraulic cylinders in a by itself known way, but in accordance with the invention which is clear fro the claims enclosed. The simplicity in the way of the invention to deter in the weight is favoured by the fact that a very great number of to¬ days lorrys as standard are provided with a tilting device, which consists of a hydraulic cylinder arranged under the platform which cooperate with revolving axles that consist of lockable hinges. The method in accordance with the invention can be used directly on such lorrys without any reconstruction of the vehicle. The devices neces¬ sary for the determination of the weight, are limited to connecting a pressure registrating device, preferably a pressure gauge gradua¬ ted ' from zero up to ten megapascal, at a suitable point of the exis- ting hydraulic system for tilting of the vehicle. The indications obtained can >e mathematically treated in consideration to the area of the hydraulic cylinder, which makes the lifting, and to certain effects of levers, by which a precise rate of the load is obtained. The method in accordance with the invention will be closer explained in the following by help of figure 1 on the en¬ closed drawing and by the general formula for a rapid determination of the weight. In figure 1 the platform on a arbitrary vehicle is shown, by which the hydraulic cylinder is not placed in the geo¬ metrical middle point of the platform and the load is unequally spread out. The symbols in figure 1 has the following meaning: a is the distance in centimeter from the tilting point S, to the working point of the force of the cylinder, b is the distance in centimeter from the tilting point S_ to the 3 working point of the force of the cylinder, c, is the distance in centimeter from the tilting point S. to the centre of gravity of the load G, d is the distance in centimeter from the tilting point S-, to the centre of gravity of the load G. The weight of the load G in kilogram is determined by the formula 1 The tare is determined by help of the method in accor¬ dance with the invention by lifting without load. a, b was measured only once, that means that they are constant for the actual vehicle. The formula 1, that means a, b, A, tare, can easily be programmed in a suitable mini computer. For the example shown,it was a CASI0-602P. The P, - and P f - indications obtained at lifting are additively fed into the computer after which G is obtained di¬ rectly in kilogram} P. and P- are the pressures in bar, indicated after a lifting. A is the cross section area in cm 2 of the cylinder. F is equal to Px A. The measuring was made on a trailer with a hydraulic tilting device. In order to be able to carry out the measuring, a pressure gauge was installed in- the fluid system. That was the on¬ ly undertaking that was necessary in order to carry out the weighing in accordance with the " invention. The weighing was carried out by lifting towards and backwards. In table 1 is shown the results of weighings at the lorry in accordance with the example, by which the tare is elimi¬ nated from the pressure values indicated. From the results it is clear that the measuring is surprising exact despite that the device is simple and has a small cost and that the time for weighing is as short as possible com¬ pared with methods and devices of to-day by which mostly "rough values of weight" have to be satisfying. OMPI In an alternative performance of the invention, the working point of the force is placed on one side of the two revolving axles and the centre of gravity of the load between these, by which a simi¬ lar mathematical situation prevails by the calculation of the weight of the load. TABLE 1 RESULTS OF WEIGHINGS ' Indicated Indicated P b P f Calculated Weight Difference Differen pressures pressures weight indicated by tilting by tilting x) by weighing backwards forwards machine MPa MPa MPa MPa Kg Kg Kg in % Load I 0,72 1,06 0,21 0,45 830 850 -20 2,4 0,99 1,64 0,48 1,03 1898 1900 - 2 0,1 1,40 1,93 0,89 1,32 2808 2800 + 8 0,3 2,15 2,33 1,64 1,72 4314 4300 +14 0,3 2,56 3,45 2,05 2,84 6225 6200 +25 0,4 Load II 0,71 0,79 0,20 0,18 490 500 -10 2,0 0,95 1,47 0,44 0,86 1638 1650 -12 0,7 1,44 2,19 0,93 "1,58 3175 3150 +25 0,8 2,42 " 3,03 1,91 2,42 5528 5500 +28 0,5 2,76 3,48 2,25 2,87 6535 6500 +35 0,5 Load III 0,72 0,86 ' 0,21 0,25 588 600 -12 2,0 1,14 1,37 0,63 0,76 1778 1800 -22 1,2 1,58 1,93 1,07 1,32 3054 3050 + 4 0,1 2,10 2,85 1,59 2,24 4873 4850 +23 0,5 3,03 3,62 2,52 3,01 7072 7050 +22 0,3 Load IV 0,75 1,08 0,24 0,47 895 900 - 5 0,6 1,12 1,25 0,61 0,64 1605 ' 1600 + 5 0,3 1,72 2,03 1,21 1,42 3366 3350 +16 0,5 2,18 2,55 1,67 1,94 4621 4600 +21 0,5 2,75 3,24 • 2,24 2,63 6232 6200 +32 0,5 x) in accordance with formula 1 - UREΛlT

Claims: PATENT CLAIMS 1. Method for determination of the weight of loads at lorrys which are provided with a platform that is tiltable around at least two mutually parallel axles, by which the plat¬ form is provided with hinges at respectively axle which each can 5 be opened or locked, by help of a hydraulic cylinder, and with one or several devices for measuring of pressure, particularly pressure gauges, that are arranged in the system of the pressure agent so . that the pressure in the hydraulic cylinder can be de¬ termined, c h a r a c t e r i s e d in that the weighing is car- 10 ried out by indicating a first pressure (P, ) in the hydraulic cy¬ linder when lifting the platform around one revolving axle and indicating a second pressure (P.) in the hydraulic cylinder when the platform is lifted around the other revolving axle and the indi cated results are mathematically treated by the formula by which the symbols in the formula has the following meaning: G = The weight of the load 20 ^" ~ indicated pressure at the 1:st lifting P f = " " " " 2:nd " a = the distance from the revolving axle to the working point of the hydraulic cylinder at the first lifting b = the distance from the revolving axle to the working point of ΛC the hydraulic cylinder at the second lifting. I ΌREA O QMPΓ

Inventors: OLSSON BENGT, OLSSON, BENGT
Applicants: OLSSON BENGT, OLSSON, BENGT
Application year: 1984
Main classification: B60P5
IPC codes: G01G19