CN87102527A - Hanging dish-type buoyancy balance - Google Patents

Abstract

Hanging dish-type buoyancy balance of the present invention is applicable to mass metrology.Compare with present widely used beam balance, have precision height, simple in structure, low cost and other advantages.Floating drum is submerged in the supernatant liquid in the airtight container fully in this balance.Following mouth and hanging scaffold that container bottom is passed in a very thin wire drawing of floating drum lower part series link.The surface tension of mouth liquid and external atmospheric pressure make not following of liquid under this balance utilization.Added surfactant in the supernatant liquid for distilled water and greatly reduced the wire drawing resistance that three-phase circumference wetting hysteresis produces when moving on the supernatant liquid surface.Improved measuring accuracy greatly.

Description

The present invention is a kind of novel buoyancy balance, is applicable to quality weighing.

Fig. 1 is for being placed on weight on buoyancy balance existing problems synoptic diagram, wherein 1-floating drum, 2-container, 3-three-phase circumference, the 4-weight in the floating drum.

Fig. 2 was placed on the in-problem synoptic diagram of buoyancy balance on the container to weight for the past.Wherein 1-weight, 2-pallet, 3-counterweight, 4-stabilising arrangement, 5-three-phase circumference, 6-floating drum, 7-container.

More existing hydraulic floatage balance meausring apparatuses as shown in Figure 1 weight is placed among the floating drum and the buoyancy balance that weight is placed on the container as shown in Figure 2 all exists some to have a strong impact on the problem of its measuring accuracy.As shown in Figure 1 weight is placed on buoyancy balance among the floating drum, if the floating drum blow-by, floating drum just can not be submerged in the supernatant liquid fully.So just must measure the height that floating drum floods.Because the influence of meniscus and length metering error, the error in dipping that this measurement causes is lower than the existing precision of beam balance with regard to the precision that makes this buoyancy balance.On the line (3) that the floating drum wall contacts with liquid level, be liquid gas-solid three touching positions in addition.The wetting hysteresis that has the three-phase circumference.This phenomenon hinders the floating drum motion, and this makes the precision of this balance be reduced to very low degree; If floating drum is sealed fully, all put into supernatant liquid, the degree of tightness of seal degree like this, the liquid measure of sealing surface adhesion all influences measuring accuracy.

Buoyancy balance as shown in Figure 2, on the pallet (2) that weight (1) is placed on the floating drum (6), and floating drum (6) is submerged in the supernatant liquid fully.The center of gravity of weight is higher than the centre of buoyancy of floating drum like this, and weight is just unstable.The pole that supports weight in addition is bent in order not bent by weight, loses the stability of depression bar, and pole can not be very thin, and the length of three-phase circumference (5) is bigger on the pole like this, and the resistance of three-phase circumference is very big to the metering influence.Prevent that in addition the device (4) that pole tilts from also having a bigger friction force to the motion of pole.Many reasons make above-mentioned buoyancy balance precision not high always.

The present invention is intended to develop a kind of novel buoyancy balance, and it is simple in structure, cheap, precision is high and adaptability is strong.

The objective of the invention is to realize in the following manner:

Fig. 3 is hanging dish-type buoyancy balance schematic diagram of the present invention, wherein under the capsule of 1-container, 2-floating drum, 3-compensation liquid, the 4-mouth, the wire drawing of 5-bottom, 6-counterweight, 7-weight, 8-hanging scaffold, 9-hanging scaffold eyelid retractor, 10-hanging scaffold eyelid retractor up-down adjustment turn-knob, 11-fixedly the crossbeam, 12-of bottom wire drawing fixedly crossbeam, 13-floating drum top filament, the 14-of floating drum top filament add device, 15-container top gas compartment, the 16-supernatant liquid of supernatant liquid.

Fig. 4 is the spacer function schematic diagram in the lower mouth, and mouth shell, 3-dividing plate, 4 are the supernatant liquid surface under wherein 1-floating drum bottom wire drawing, the 2-.

Fig. 5 when not having dividing plate in the following mouth, the synoptic diagram of floating drum bottom wire drawing off-center silk, under wherein 1-floating drum bottom wire drawing, the 2-behind mouth shell, 3-supernatant liquid surface, the 4 floating drums bottom wire drawing offset distance central hair, the supernatant liquid of invading in the slit between wire drawing and the following mouth.

Fig. 6 is practical following mouth synoptic diagram, wherein mouth endpiece, the bottom wire drawing of 4-floating drum under mouth shell, 2-dividing plate, the 3-under the 1-.

Fig. 7 is for to overcome the influence of temperature to float buoyancy with identical floating drum by lever.

Container (1) top seal has supernatant liquid (16) in the container, supernatant liquid is distilled water or running water, adds activating agent in the supernatant liquid. Floating drum (2) is submerged among the interior supernatant liquid of container fully. Floating drum can be various shapes. Floating drum upper end is connected to a filament (13) and passes liquid level, and the wire drawing of its diameter and lower end (5) is basic identical, and pulling force that the buoyancy of the floating drum that the diameter of wire drawing is subjected to according to wire drawing produces is definite. Container (1) lower ending opening place is connected to a lower mouth (4), as shown in Figure 4. One dividing plate (3) is arranged in the lower mouth, and dividing plate central authorities have one than wire drawing (1) only big 0.1 millimeter or littler hole. Container bottom has an aperture. As shown in Figure 3, an external rubber bladder of filled with fluid (3) not, the height of rubber bladder (3) is identical with the port of export of lower mouth.

The container top seal utilizes the surface tension of the pressure of atmosphere and lower mouth place liquid to guarantee that liquid can lower; Add activating agent in the supernatant liquid, greatly reduce the stiction of three-phase circumference, make measuring accuracy become hundred times of raisings; It is basic identical that floating drum upper end passes the diameter of the diameter of filament of liquid level and the wire drawing of floating drum bottom, the amount that makes floating drum arrange liquid in any position all is constant, thereby guaranteed to be subjected to all the time a stable upper pulling force on the hanging scaffold, utilized this upper pulling force just can carry out weighing to object. The weighing process is such: earlier add counterweight at hanging scaffold, make the weight of counterweight make the hanging scaffold balance, subtract lower a certain amount of counterweight after putting then weight, again make the hanging scaffold balance. The weight of the counterweight under at this moment subtracting is exactly the weight of weight. Such as the slightly larger in diameter of top filament in the diameter of bottom wire drawing, floating drum, hanging scaffold more down, the pontoon string liquid measure is just more big. Just can measure very small changes in weight according to the height of floating drum and hanging scaffold equilbrium position like this. There is a dividing plate (3) at lower mouth (as shown in Figure 4) middle part, the aperture of dividing plate central authorities only than bottom wire drawing more greatly, slit between aperture and the steel wire is very little like this, the resistance that flow is crossed is very big, even a certain moment floating drum is subjected to very big impulsive force in the weighing process, liquid has the trend that flows downward, also only have very little very little liquid can flow through dividing plate, slowly flow back to again subsequently container and return to original situation, guaranteed that floating drum is hit power and has not a particle of lower of liquid in the weighing process. In addition, dividing plate is fixed on wire drawing avoids wire drawing to make its surface tension be attached to wire drawing tightly on the tube wall near immersing water (position that (4) refer in such as accompanying drawing 5) in the contact slit between wire drawing and lower mouth wall behind the tube wall on the center line, produce frictional force, liquid contacts with the wire drawing out of plumb and makes it the growth of three-phase circumference simultaneously, increase the frictional force of three-phase circumference, reduce precision. More reasonably descend mouth structure as shown in Figure 6, the hole of lower mouth outlet (3) is also very little, only than the hole on the dividing plate more greatly. Can guarantee that like this wire drawing does not contact with lower mouth outlet, makes again supernatant liquid surface, Xia Zui exit produce bigger capillary force simultaneously and makes liquid level more stable. One is not The rubber bladder of filled with fluid is to the cold and hot variation redeeming that causes of liquid volume, and height and the rubber bladder of lower mouth are basic identical, and it is too much or very few to prevent that liquid from depositing in rubber. Float buoyancy changes with ambient temperature very little variation, because the time range of weighing is smaller, this impact is very little. Can control temperature changing speed by container is added heat-insulation layer in addition, identical floating drum (2) that also can be by as shown in Figure 7 is floating drum by way of compensation, be placed with certain material (3) in the middle of this floating drum, make the buoyancy of this floating drum close to zero. But the buoyancy of this floating drum and the temperature variant rule of float buoyancy of hanging hanging scaffold, size is on all four. Both variations can be passed through lever (4) and offset fully, thereby have overcome the problem that float buoyancy changes with change of external conditions.

The present invention has following advantage:

1, precision height of the present invention.The resistance of the system motion that connects according to unique obstruction hanging scaffold, floating drum top filament and bottom wire drawing are in the calculation of resistance of supernatant liquid surface three-phase circumference, high-tensile steel wires with 1 millimeter of diameter and 2 millimeters can hang 100 kilograms and 400 kilograms, and relative accuracy can reach 2.7 * 10 respectively ^-10With 6.75 * 10 ^-11

2, simple in structure, handling ease, with low cost.The present invention does not have material expensive especially, and the crossbeam that requirement on machining accuracy is high and the edge of a knife, cutter such as hold at device.On the other hand, the motion of floating drum in liquid is exactly a visous damping motion in liquid, and this balance need not damper.Make like this that in the past high-precision balance can only be in equipment plant produced preferably, and can little factory produce at general glass now that cost reduces greatly.A precision 5 * 10 ^-7The beam balance that weighing is 20 kilograms, price are units up to ten thousand, and this buoyancy balance counterweight has only hundreds of unit outward.

3, range of weighing is unrestricted.One table flotation tube diameter 100cm balance weighing can reach 600 kilograms, the claimed 77Kg of diameter 50cm.

4, adaptability is strong.There are not precision apparatus such as the edge of a knife in this buoyancy balance, so be not afraid of vibrations, does not need strict level conditions, and not fragile, the life-span is long, need not special maintenance.

Claims (5)

1, a kind of hanging dish-type buoyancy balance is characterized in that being made up of airtight container, floating drum, supernatant liquid, hanging scaffold, wire drawing, Xia Zui, floating drum top filament and supernatant liquid compensation bag.

2, buoyancy balance as claimed in claim 1 is characterized in that being added with in the supernatant liquid activating agent.

3, buoyancy balance as claimed in claim 1 is characterized in that in the mouth dividing plate being arranged down, and a hole more bigger than wire drawing arranged in the dividing plate, and the diameter of following mouth outlet is more bigger than the hole on the dividing plate.

4, buoyancy balance as claimed in claim 1 is characterized in that supernatant liquid compensation bag is connected to container bottom, and its position is high together with following mouth endpiece.

5, buoyancy balance as claimed in claim 1, it is characterized in that the floating drum top is perpendicular has one than slightly thick any the filament of bottom wire drawing.

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