CH653771A5 - Device for selbstpruefende praezisionswaegeeinrichtungen. - Google Patents

Description

653771 2

PATENT CLAIM determined to expand mass value in his area and each

To make the device for self-checking precision weighing device weighing cycle controllable. The number of lines are to be reduced by the switching weights of the switching weights and the control by force transducers and the or force compensation system to simplify the electronically determined lifting mechanism.

Mass value in its range and per weighing cycle controlled. According to the invention, the object is achieved in that it can be characterized, characterized in that only one motor-operated shift lever, one shift weight,

actuated shift lever (2), a shift weight (1), in which the electronic plus measuring range of its mass, the electronic plus measuring range or minus measuring range of the force transducer or force comm.

Corresponds to the minus measuring range of the force converter or force compensation system, corresponds to a calibration system in the calibration position, is connected to a load carrier in the calibration position and is mechanically connected by means of a mass carrier (4) and mechanically balanced by means of a mass (15) on the lever and in the lifted position of the lever (6) is balanced and in the lifted position of the switching weight a minus end value of the electronic measuring

Switching weight (1) is a minus end value of the electronic area of the force converter or force compensation system.

Measuring range of the force transducer or force compensation system or zero point of the weighing range via a computer system (11) or zero point of the weighing range is assigned via an is.

Computer (18) is assigned. In the balanced state of the lever, the force converter or the force compensation system is not loaded. In

the higher position of the switching weight becomes an electronic one

Lower limit of the electronic measuring range of the force

20 transducer or force compensation system reached. The

The invention relates to a device for a self-checking characteristic of said electronic measuring range

Precision weighing equipment, in which the plus and minus ranges are mirror images of one another thanks to switching weights. The minus

the value determined by force transducer or force compensation system is set electronically by a computer in its area and is set to zero. This means that the overall electronic measurement

Weighing cycle can be controlled. 25 rich or doubled weighing range.

Scales are known in which the weighing process, the weighing of a load, the control of the calibration point and the electronic measuring range, as well as the measuring range which can be achieved by means of force transducers or force compensation systems, are expanded by means of switching weights. The mass of which includes a doubling of the measuring range is carried out

Switching weight is added as an electronic fixed value to the value determined in the present arrangement per weighing cycle in three variable measuring ranges. The total of 30 steps:

represents the total.

Such designs are, for example, in DE-OS 1st calibration position

2 050 596 and described in DE-AS 2 621483. In - switching weight placed on load carrier, mechanically on

DE-OS 2 056 714 describes an electronic balance, counter-balanced lever, force converter or in which the mass of a switching weight is less than the max. 35 force compensation system is not loaded.

male measuring range is. The maximum measuring range is made up of a second measuring range control consisting of a variable measuring range = mass of the - shift weight by means of a motor-operated shift lever

Switching weight + overload range + underload range. Too withdrawn, minus value of the mirror-image electronic

The automatic measuring range is checked as a result of the load of the displayed measuring range.

automatic switching of switching stages and thus the weighing range 40 3rd edition and weighing of the load switchover possible. - by arithmetically setting the minus final value to zero,

As a further variant, the use of the switching range of the measuring range is doubled.

important as a reference weight in DE-OS 2 601 165

described. This is about a scale in which a switching device.

weight is provided as a reference weight. In the following, the reference device is simplified based on a scale.

rich. When the reference weight is applied by a lifting mechanism, the final value of the electronic measuring device is checked. FIG. 1 shows a schematic representation of a precise range. ion weighing device in calibration position.

For the solutions described, the effort is such that FIG. 2 shows a schematic illustration of a precise

relatively high compared to the use value achieved. It sionswägeinrichtung in the minus value of the electronic either a switching weight with high accuracy measuring range.

as a reference weight for measuring range control or switching - Figure 3 shows a schematic representation of a pre-weight required for extending the measuring range. For this sion weighing device in weighing position.

Switching weights each require a lifting mechanism with an SS corresponding drive and a control. The basic structure can be seen from Figure 1. A switching weight as a reference weight and switching weights load shell 5 is based firmly on a load carrier 4, which combines with a scale 6 to expand the measuring range, a lever 6 and a link 7 forms a four-bar linkage,

So there are at least two shift weights, two. The lever 6 is supported in the bearing 8 and the handlebar 7 in the bearing

Lifting mechanisms and a more complex control system are not required and these are fastened to the frame 10. A shift weight maneuverable. 1 is a switching lever 2, from a cam 3,

The aim of the invention is a device for self-testing, which is controlled and motor-driven, precision lifting devices with extended use, lifted or placed on the load carrier 4. To create mass balancing of the switching options, with a higher accuracy class and weighted 1 and the dead weight of the load carrier 4, the shell has a fold structure and less effort. 65 5 and the proportional handlebar mass 7 is on the opposite. The invention is based on the object, with a precision lever arm of the lever 6, a balancing mass 15 attached, sionswägeinrichtung the by switching weights by the coil 14 and the proportional mass of the lever 6 kom force transducer or force compensation system has an electronically compensating effect. The coil 14, the permanent magnet 16, the

3rd

653771

Inductive displacement transducers 12 and the evaluation module 13 together form the force compensation system 11, to which the analog-digital converter 17, the computer 18 and the display content 19 are connected. The lever 6 is balanced in FIG. 1, consequently no current I flows, which is evident from the characteristic curve at the measuring point 20. At the same time, the calibration position is automatically checked (display = + 800.00 g, see characteristic curve in measuring point 21). This is the first step in a weighing cycle.

The second step of a weighing cycle is shown in FIG. 2. The shift weight 1 is lifted from the load carrier 4 by means of the shift lever 2 from a cam disk 3 which is controlled and driven by a motor. The moment at the coil 14 is reduced, the lever 6 is deflected from its rest position. This path change causes an inductance change in the inductive position transducer 12. In the evaluation module 13, this change in inductance is converted into a current I proportional to the deflection, which flows through the coil 14. This current flowing in the field of the permanent magnet 16 generates a force which counteracts the deflection of the lever 6. The current intensity I is directly proportional to the shifted or applied switching weight 1 or the load 22.

The value -800.00 g can be seen from the characteristic curve in measuring point 20.

The third step of a weighing cycle is shown in FIG. 3. The starting point is the second step. The maximum minus value of the electronic measuring range, for example -800.00 g, is set to ± 0.00 g in the computer 18 s (characteristic curve in measuring point 21). For the load 22 to be determined, the electronic weighing range from the minus end value (e.g.: -800.00 g = 0.00 g) to the plus end value (e.g.: + 800.00 g = io 1600.00 g) is available. With this solution it is achieved that the following further advantages are achieved with only one shift weight 1, one shift lever 2, with a simplified control and a motor-driven cam 3:

15

- The calibration point and the measuring range are checked for each weighing cycle. This is a prerequisite for high-precision verifiable weighing equipment.

- Doubling of the electronic measuring range of the 20 weighing system.

- By using the analog-digital converter 17 in the plus and minus range (provided as standard), the ratio of resolution - effort is cheaper by a factor of 2.

B

3 sheets of drawings