SU1760359A1 - Balance - Google Patents

Abstract

Use: weight measuring technique. The essence of the invention. The pedal 26 manually releases the inner hollow roller 23 and by pressing the button 25 moves it along the outer hollow roller 16 until the driver 24 engages the hollow sphere 1. The fluid supply unit handle raises the fluid level in the landing bowl 2, centering the extensions 4, made in the form of two elastic tapes fixed by the first ends on diametrically opposite sides of the hollow sphere in the horizontal plane are destroyed, the floor of the sphere 1 pops up due to the difference in the weight of the load and weights on the angle limiter. Use the adjustment knob 22 to twist the coil spring 19, the floor 1 of the sphere 1 is removed from the stops. A weighting device is determined from the reading device and added to the weights. Fine tuning is done with pens. By the autocollimator 10, the deflection angle of the mirror pad of the hollow sphere 1 is read. f-ly, 2 ill. k / i 1C

Description

The invention relates to a technique for weighing masses in the range of 0-20 g.

Quartz scales are known that contain equal arm rods and a number of rigid quartz parts. Their disadvantage is the influence of external factors (vibration, temperature, etc.) on the quantity being weighed.

Known scales, in which the support and the yoke is made in the form of a hollow sphere, placed in a bowl with liquid. Scales contain cups with flexible suspensions, fluid supply mechanism. A mirror platform is made on the hollow sphere, from which the rotation angle is removed using an autocollimator.

The differential weight of the load and the weights are determined by the angle of rotation of the mirror pad of the hollow sphere.

These scales allow to eliminate the influence of external factors. However, their disadvantage is the free floating of the hollow sphere in the liquid and there may be cases when the sphere touches the bowl with the liquid during weighing, which creates additional friction points that distort the results of weighing. In addition, the movement of the hollow sphere in the plane of the sea makes it difficult to take a readout from the mirror site. These disadvantages lead to a decrease in the reliability and accuracy of the scales.

The equilibrium position of the sphere does not depend on the level of immersion of the sphere and the scales potentially have a wide weighing range.

However, the principle of weighing by deflection used in these scales significantly limits the weighing range.

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The autocollimation measurement method is carried out within a small angle (+ 1 °), which corresponds to a very small difference weight. The equilibrium equation at small angles is

Rd Ra AGR,

AG

whence a - r, d

where RD is the imbalance of the hollow sphere;

R is the radius of the hollow sphere;

AG - differential weight.

So, for example, when the balance is operated with a difference weight of up to 1 mg and the maximum deviation angle is of the order of Yuugl. min, the required imbalance of the RD sphere should be of the order of (0.1-0.2) mg.

When measuring large masses (from 1 to 0.01 g) and in the absence of a balancing system, this method of measuring the angle of rotation of the rocker arm is ineffective, since provides a narrow weighing range, which is a disadvantage of these weights.

Various systems of balancing weights are known, among them, in particular, balancing systems with elastic elements.

For example, balancing with a torsion thread is widely used in quartz weights. In these weights, one of the branches of the torsion thread, on which the rocker arm is suspended, is connected to a mechanism for twisting this thread and measuring the twist angle. A significant drawback of the torsion balancing method is the insufficient structural strength, since the measuring torsion thread at the maximum twist angles experiences a double load: from its twisting and from stretching by the rocker arm and weights, which leads to breakage of the scales.

Known scales, which eliminated this drawback due to the fact that the suspension system of the rocker arm is separated from the torsion measuring thread. Torsion thread balancing systems are mainly used in highly sensitive scales designed for weighing small weights. The ultimate loads of such weights are usually (1-0.001) g, and the absolute sensitivity is

Scales with torsion thread and independent suspension of the rocker have a complex spatial design, have a limited weighing range, which is their disadvantage.

As a prototype, take a scale containing a yoke, made in the form of a hollow sphere with flexible cup hangers.

respectively for cargo and weights. The floor of the sphere is installed in the landing bowl, which communicates with the fluid supply unit. On the sphere there is a mirror playground, with

wherein the autocollimator reads an angle proportional to the measured mass.

Scales operate on the principle of weighing by deflection. The disadvantages of these scales are low reliability and accuracy due to the contact of the hollow sphere with the bowl when working in a liquid, and the limited weighing range inherent in weights operating by deflection.

5 The aim of the invention is to increase the reliability, accuracy and expansion of the weighing range towards larger values. This goal is achieved by inserting an elastic element in the balance, a limiter for the vertical movement of the hollow sphere and centering its stretch, made in the form of two elastic bands fixed by the first ends on diametrically opposite sides of the hollow sphere in

5 are horizontal planes, the longitudinal axes of the elastic bands and the flexible suspensions are located in mutually perpendicular vertical planes, and one of the second ends of the elastic bands is fixed through the elastic element.

The goal is achieved by the fact that a rotational support and a calculating device connected with it are inserted in the balance, the first of the second ends of the elastic bands is fixed on

5, a rotation support mounted coaxially with a hollow sphere, and the fluid supply unit is provided with a level gauge.

The goal is also achieved by the fact that a drum with a spiral spring attached to it at one end, a second reading device connected to the drum, made with a tuning knob, an additional support, two hollow rollers and one mounted on another, spring-loaded in the direction from the hollow sphere and installed with the possibility of interaction with the internal hollow roller, which is located coaxially relative to the second of the second ends of the elastic bands with the possibility of axial movement and interaction with p loi leash area formed on its end, with an external hollow roller installed in more opo5 D and passed through a drum with a spiral spring, is attached the other end of the latter.

The positive effect is ensured by the exclusion of swimming and the contact of the hollow sphere with the landing bowl during weighing, which ensures the reliability of the measurement of the weighed masses. The elastic element prevents stretching from breaks, and the vertical movement limiter is a catcher of the hollow sphere under the action of excess buoyancy from the fluid when measuring the load.

The rotation support with a reading device in combination with stretching allows the weighing range to be extended in the direction of larger quantities. The insertion of the level gauge allows you to relieve the stretch (create zero buoyancy) during weighing, which provides increased accuracy. The insertion of a coil spring drum associated with a second reading device allows an even greater expansion of the weighing range towards larger values. All these new technical solutions create a technical and economic effect.

FIG. 1 shows a section of weights in the plane of horizontal centering extensions; in fig. 2 shows a device for balancing by spiraling a coil spring, which encloses one of the straps in FIG. one.

The scales contain a hollow sphere 1 placed in a bowl 2 with a liquid, a liquid supply mechanism 3, horizontal centering extensions 4, a rotation support 5, an elastic element (damping spring) 6, a gear 7, a reading device 8, a level gauge 9, an autocollimator 10, flexible suspensions of cups 11, a trimming knob with a screwdriver twisting device 12, a fine adjustment knob 13, a knob for controlling the fluid supply mechanism 14, a twisting spring trimming device of a coil spring 15, a hollow guide roller 16, supports 17 (for example, stone), drum tribka 18, coil spring 19, toothed link 20, scale of the second reading device 21, knob for setting the coil spring 22, hollow roller 23 with a leash 24, movement button 25, spring-loaded pedal 26, spring 27, hook 28.

When weighing an unknown load, knowing its approximate weight, this load and weights, approximately equal to its weight, are placed on the cups 11.

By pressing the spring-loaded pedal 26 and turning it around an axis, the hook 28 is pulled out from the holding position of the hollow roller 23 and inserted into the recess of the device 15 (in the position shown by the dotted line in Figure 2). By pressing the button 25, the hollow roller 23 is moved along the stretching along the guide

the roller 16 as far as it will go, while the leash 24 will enter into engagement with the hollow sphere in the zone of embedding it with a spreader 4.

The control knob 14 of the liquid supply mechanism 3 sets the level of the liquid according to the level indicator 9, which corresponds to the zero buoyancy of the hollow sphere with the load on the cups (the buoyancy plane is set to a certain mark on

level gauge, in which the total weight of the hollow sphere with flexible cup hangers and the load of the load and weights, approximately equal to the lifting force). In this state, the horizontal centering extensions 4 are unloaded to a small amount of force acting on them due to the inaccuracy of the preliminary estimation of the load. At the same time, the floor of the sphere emerges and, due to the difference in the weight and weights, lies on the angle limiter in

the plane of arrangement of the flexible hangers of the cups 11. Structurally, this angle is selected on the order of 5 ° (in the figures the stops are not shown). Using the knob 22, the coil spring 19 is twisted to the moment when the sphere is removed from the angle limiter and on a scale of 21 the count is measured in milligrams proportional to the moment generated by the coil spring. The spiral spring operates in a linear twisting region, i.e. in the zone of the angle of rotation pa, at which the moment of twisting is proportional to the angle a (n is the number of revolutions). With the help of transfer 20, the drum 18 flange transmits rotation

The coil spring 19, the latter, when energized by its potential energy, transfers the rotation to the guide roller 16, which rotates in the stone supports 17 together with the roller 23. The moment of friction

rotation of the guide roller 16 in the stone supports is negligible and is balanced by preliminary twisting of the coil spring during its calibration when assembling the scales, and the moment of friction

The telescopic connection of the roller 23 with the roller 16 is sufficiently large, which ensures the transmission of the angle of rotation of the rocker arm. The balancing device 15 using a coil spring is calculated for a balancing range of up to 1 g. In the composition of the weights, the device 15 is used as a coarse balancing system. After assessing the gross weighting using the device 15, the handle 14 reduces the level

liquids until the floor of the sphere with the children on the support of the bowl 2, turning the pedal 26. Due to the spring 27, the leash 24 leads out of engagement with the hollow sphere, while the hollow roller 23 returns to its original position

the position, the knob 22 sets the scale to zero, and the measured weighting is added (or subtracted) to the weights mounted on the cup. Next, an exact balancing process is carried out with the aid of the device 8 by twisting the centering straps 4. Precise balancing by twisting the straps provides a weighing range from 0 to 1 mg. When this is set using the handle 14 of the lifting mechanism of the fluid level gauge 9 at the zero buoyancy mark of the new load with an added weights.

Using the fine adjustment knobs 12 and 13, the spreaders are twisted at an angle such that the sphere is removed from the limiter of the angle of rotation of the flexible cups and tends to zero equilibrium position, while the mirrored area of the hollow sphere enters the pickup zone of the autocollimator and the deflection angle is + 10 read this angle. According to the total weight of the weights, the exact weighting, read on the scale of the device 8 and the deviation angle of the autocollimator, find the mass of the weighed cargo.

Thus, using a coarse balancing device 15, covering a measuring range of 0-1 g, a precision balancing device covering a range of 0-1 mg, and an optical system covering a range of 0-0.1 mg, provides a measurement using a relatively large mass method up to 20 g with a sufficiently high accuracy determined by the accuracy of the reference weights.

The insertion of centering extensions into the scales eliminates the swimming and touching of the landing bowl during weighing, which ensures the reliability of the measurement of the weighed masses, the reliability and accuracy of the scales are increased. The elastic element, made in the form of a shock-absorbing spring, prevents stretching from breaks. The vertical movement limiter is a catcher of a hollow sphere during its movement from the action of excessive buoyancy force. The insertion of a rotational support with a reading device and the fixing of one of the extensions on it is an exact balancing device and ensures that the weighing range is extended to a larger value. The insertion of the level gauge allows unloading the stretch from the excessive buoyancy force at different loads, in the full range of measured values, which provides increased accuracy. The introduction of the drum with a coil spring and the second reading

Claims (3)

1. Scales containing a yoke, made in the form of a hollow sphere with flexible cup hangers, respectively, for cargo and hinges, installed in the landing bowl communicated with the fluid supply unit, characterized in that, in order to increase reliability and accuracy, elastic the element that limits the vertical movement of the hollow sphere and stretches it centering it, in the form of two elastic bands fixed by the first ends on diametrically opposite sides of the hollow sphere in the horizontal plane, with the longitudinal axes of the elastic bands and flexible suspensions are located in mutually perpendicular vertical planes, and one of the second ends of the elastic bands is fixed through the elastic element. 2. Weights according to claim 1, characterized in that, in order to extend the weighing range towards larger quantities, a rotational support and an associated reading device are inserted in them, with the first of the second ends of the elastic bands fixed to rotation support mounted coaxially on the / sphere, and the fluid supply unit is made with a level gauge. 3. Scales on PP. 1 and 2, about tl and h and y y and e with the fact that they introduced a drum with a coil spring attached to it at one end, a second reading device connected to the drum, made with a setting knob, an additional support, two hollow rollers mounted on one another and manual pedal, spring-loaded in the direction from the hollow sphere and installed with the ability to interact with the internal hollow roller, which is located coaxially relative to the second of the second ends of the elastic bands with the possibility of axial movement and interaction with the hollow sphere with a lead made on its end, and to the external hollow roller mounted in an additional support and passed through the drum with a spiral spring, attached to the second end of the latter. JO cr 1L M about iQ r 15 I FIG.