DE3204342C2 - Device for determining the compressibility of a stream of cut tobacco materials - Google Patents

Abstract

To determine the filling capacity of a continuous stream of tobacco, on the one hand the height of a defined, unloaded area of the tobacco flow and on the other hand the height of the same area of the tobacco flow compressed by a defined load is determined; then a measure of the filling capacity is obtained from the two heights.

Description

characterized by the combination of the following features:

d) the two sensors (14, 16) lie on a stream of cut tobacco during preparation of the tobacco Tobacco materials on, which is transported as a tobacco fleece over a flat surface will;

e) with each sensor (14,16) there is a wave (22,39) rigidly connected, which is coupled to a sin potentiometer (24);

f) the Sfr potentiometer (24) are voltage / frequency converters (50, 51) for the conversion the analog output signals connected to digital signals; and

g) with the device (52, 53, J6, 58, 60) for determination the compressibility from the difference between the digital output signals of the two voltage / frequency converters (50, 52) is a time control (54) for the temporal correlation of the two measuring points the transport speed of the tobacco fleece (12) connected.

2. Apparatus according to claim 1, characterized by a flat conveyor belt (10) for transport of the tobacco fleece (12).

3. Device according to one of claims 1 or 2, characterized in that each sensor (14, 16) has a roller (32, 44) resting freely rotatably on the surface of the tobacco fleece (12) and around a bearing point (D \, D ₂ ) has pivotable rods (28, 40) for holding the roller (32, 44), which are rigidly connected to the associated shafts (22, 39).

4. Device according to one of claims 1 to 3, characterized in that the shafts (22,39) of the two feelers (14, 16) on one of the flat surfaces (10) parallel reference line.

5. Device according to one of claims 1 to 4, characterized in that the device for Determination of the compressibility in each case an integrator (52,53) for the digital output signals of the associated voltage / frequency converter (50, 51) and a multiplexer (56) for the supply the output signals of the two integrators (52, 53) to a computer (60), and that the Time control (54) connected to the two integrators (52, 53), the multiplexer (56) and the computer (60) is.

The invention relates to a device for determining the compressibility of a stream transported over a flat surface; cut tobacco materials the type specified in the preamble of claim 1.

As the "compressibility" of cut tobacco, the specific volume change of a certain Tobacco mass under load by a weight or a force denotes With a constant load area of the volume of tobacco examined in each case, it is sufficient to refer to differences in height with or without exposure on the unencumbered height to consider.

The compressibility affects the product quality, particularly the hardness and end failure as well In addition to the tobacco weight used, the raw material costs of the smokable article are also calculated.

In an article from "Contributions to Tobacco Research", Volume 4, Issue 7, Dec. 1968, page 293 ff, a combination measuring device described for the compressibility of stringed tobacco materials and the hardness of cigarettes, where the column height of a defined tobacco weight is used to determine the compressibility is measured under a certain load after a set time. A similar procedure is also available from an article in "Tabak-Journal-International", 1980, Issue 2, page 125 known, with additional a centrifuge process is explained. The disadvantage in each case is that it is a discontinuous one Is a procedure that is only suitable for random sampling; in particular, it is not possible in a continuous measurement during production of the compressibility of the cut tobacco materials to determine.

Furthermore, a continuous process has been proposed in which the cut Tobacco falls down in a vertical tube, the side walls of which are formed by powered conveyor belts will. Under this tube there is another endless belt, which is provided with a load cell is so that the weight of the tobacco resting on the conveyor belt can be determined. The pages of the tube are transparent, so that by means of a photoelectric height control system the speed of the conveyor belt arranged under the pipe can be set and thereby it can be ensured that always results in the desired column height in the pipe. The compressibility of the tobacco can vary from the amount of Tobacco column can be determined in the ilohr. This method however, requires a lot of equipment and is relatively imprecise.

An application of this principle for a similar purpose, namely for the delivery of tobacco quantities with constant weight, is described in DE-OS 28 54 098.

A device for determining the compressibility of a material transported over a flat surface Current from cut tobacco materials of the specified type is known from GB-PS 14 68 169 and v ^ eis a first sensor for measuring the height of an unloaded area of the tobacco stream at a first place, a second sensor for measuring the height of a compressed by a defined load Area of the tobacco stream at a / wide point as well as a device for determining the Compressibility from the difference between the two heights. This device is in the real Cigarette machine arranged, namely at the point where the cut tobacco materials up

3 4

sucked against a contact surface and thereby taken along.

men will be. The two sensors are shown in the example below with reference to the enclosed.

geti the surface of the held on the contact surface, the schematic drawings explained in more detail

Shows pressed layer of cut tobacco materials

The disadvantage of the known device is that the s Fig. 1 shows a principle representation of the mechanical

Electricity from the cut. Tobacco materials already part of the device for determining the compressibility

is under the action of suction and by doing cut tobacco materials,

this suction force is deformed, so the measurement of the F i g. FIG. 2 is a view in the direction of arrows AA from FIG

Height of the unloaded area of the tobacco flow is F i g. 1,

already by the deformation due to the suction force ver io F i g. 3 a representation of the geometrical relation

is falsified and this results in measurement errors that affect the individual parts,

the reproducibility of the measurement results in question Fig.4 of the. Circuit structure of the evaluation device

place. In addition, id of British patent specification tung, and

not specified in what way the actual F i g. Fig. 5 is a timing diagram showing the timing of the measurement quantity from the position of the two sensors. will be. A loosely piled mass of sliced ta-

The invention is therefore based on the object of baking materials, such as, for example, leaf cuttings, ribbons

a device for determining the compressibility of cut foils or mixtures of these

a stream of cut tobacco materials of the components, also known as "tobacco fleece"

To create the specified genus, with which the grain is 20, is shown in FIG. 1 indicated by the reference source 12

sensitivity in a simple way from a technical evaluation point of view and is carried out by a conveyor belt 10 mi; flat surface

precisely, i.e. without being influenced by additional outer surfaces, conveyed diagonally upwards in the direction of the arrow.

Forces, can be detected. The conveyor belt 10 is located in a part of the

This task is achieved according to the invention by the so-called »tobacco preparation in the processing line.

characterizing part of claim 1 specified 25 riding «, so that in this respect no additional constructive

Features resolved ven measures are needed.

Expedient embodiments are in the lower and upper tobacco fleece 12 are two measuring devices

claims compiled 14 and 16 arranged with the in the direction of transport

The advantages achieved with the invention are also based on the tobacco fleece 12 initially provided measuring device, that the measurement of the compressibility 30 device 14 the height h \ (see also Fig. 2) of a certain during the tobacco preparation, so for example in th, unloaded area of the tobacco fleece determines the cigarette production in front of the cigarette machine of the end product, however, is possible under the effect of a precisely defined product "cigarette". The measurement of the grain force is somewhat compressed, as shown in FIG. 1 Pressibility occurs from a loosely piled tab.

bakvlies, as it is in the Tsbak preparation on several The first measuring device 14 has a stationary

Make available so that this tobacco fleece support surface 18 for two bearings 20 (see also Fig. 2)

40 a shaft 22 is not influenced by additional external forces. The center of the shaft 22 is in

and therefore the measurement is a very exact measure for the F i g. 1 indicated by the reference symbol D \

Provides compressibility. There are two fasteners on the shaft 22

The two, from the angular position of the two sensors 26, two rods 28 attached, which on the according to the

dependent measurement signals are represented in FIG. 1 left side a counterweight 34

ter won, so that this Meßsignaie carry in a linear 45 and on the opposite side with a

Relationship to the respective existing height of the hub 30 of a roller 32 are connected. The role 32

bakvlies stand and therefore lies freely rotatable without any problems, practically without any load on the

let work. Surface of the tobacco fleece, since the weight of the

In order to enable accurate measurements, the roller 32 and its support must be supported by the counterweight

The measurement signals supplied by the two sensors are exactly 50 34 compensated.

be synchronized so that during processing, one of the rods 28 is driven by a motor.

the same places of the tobacco fleece assigned heights level, rotating brush 47 attached, which on the surface

be evaluated. This is done via a also before the roller 32 is applied in order to tobacco adhering there

Take into account the transport speed of the tobacco fleece.

tending timing for the processing of the measurement si- 55 The roller 32 rises and falls according to the

gnale and the determination of compressibility from the height h \ of the unloaded tobacco fleece (see also -

Difference between the two heights. F i g. 3), whereby the rigidly connected to the rods 28

The digital processing of the measurement signals offers ne shaft 22 is rotated accordingly. With the according likewise the advantage of high accuracy in connection with the representation in FIG. 2 right end of shaft 22 is with little electronic effort, the axis of a sin-precision being expediently 60 via a coupling 23 a computer for evaluating the sipototiometer 24 is connected, so that there ?; Output signals is used. signal of the potentiometer 24 of the rotation of the shaft 22,

Such a computer can then depending on the position of the roller 32 and thus ultimately the

the tobacco preparation height h \ of the tobacco fleece under the roller 32 corresponds to the determined compressibility

influence, that is, by changing certain parameters f.5 The second measuring device 16 has a similar one

ter, such as temperature, humidity, cut structure, so also has a stationary support surface

width of the tobacco material and tobacco use weight before 36 with bearings 38 on a shaft 39, which is rigid with

to regulate the manufacturing process. Rods 40 are connected; the rods 40 support one

Hub 42 of a roller 44 which rests on the surface of the tobacco fleece 12. To increase the load on the Tobacco fleece additional weights 46 are attached to the roller 44 so that the tube 44 extends deep into the Presses tobacco fleece 12, as can be seen in FIG. 1.

In the case of the second measuring device 16, too, the position of the roller 44 and thus the height A _a {see FIG. 3) dependent angular position of the shaft 39 is detected by means of a sin precision potentiometer, not shown

The geometric relationships between the essential components are shown in FIG. It can be seen that the center points of the two shafts 22 and 39, indicated by the reference symbols D \ and Dj, lie on a reference line which runs parallel to the support surface for the tobacco fleece 12, that is, parallel to the conveyor belt. According to the height of the loaded or unloaded tobacco fleece 112 raise and lower the rollers 32 and 44, so that the corresponding rods 28 and 40 are rotated about the shafts 22 and 39 and assume an angular position that depends on the respective height of the Tobacco fleece depends.

If the roller 32 lies on the conveyor belt 10, there is therefore no tobacco fleece 12 on the conveyor belt, as in FIG. 3 is indicated by the dashed roller 32, the rod 28 forms an angle λ o with the reference line. The perpendicular from the center of the roller to the reference line has the length yo. If the constant distance between the pivot point D _x and the center of the roller 32 is denoted by r, then yo can be expressed by:

yo

sin * o

Has the TabakvlicS i2 in the unencumbered. If the filling level Ai is reached, the rods 28 form an angle x \ with the reference line, and the perpendicular from the center of the roller 32 to the reference line has the length y \. Then y \ can be expressed by:

yi - r ■ sin & \.

The filling level Ai is equal to the difference between yo and y _t , so that:

h \ = yo-yi = r (sin «o-sini * i).

The height Ai of the tobacco fleece thus depends on a Sin function of the angle between the reference line and the rod and thus the position of the roller 32, so that by using sin-encoders as measuring transducers a measured variable is obtained which is linear depends on the height of the tobacco fleece to be determined.

Similar considerations apply to the filling level A _{2 of} the compressed tobacco fleece, as in FIG. 3 is also indicated schematically, where y _c and y ₂ again represent the perpendicular from the center of the roller to the reference line.

To achieve this linearity and the direct comparability of the measured angles and thus the associated It is essential that the reference line is parallel to the tobacco base, in this case! so to Conveyor IC, runs

The two sin precision potentiometers thus provide output signals that each represent a measure of the current height Ai or A _{2 of} the tobacco fleece 12, on the one hand for the unloaded tobacco fleece and on the other hand for the tobacco fleece compressed by a defined load. These measurement results are processed further in the evaluation circuit shown in FIG. 4, the two measurements being synchronized at the same time, since it is essential that only those measurements are correlated that were carried out on the same area of the tobacco fleece 12.

ίο The in F i g. 4, the following three signals are supplied:
U \ (t), the output signal of the potentiometer of the first measuring device 14, which represents a measure of the height h \ of the unloaded tobacco fleece 12,

is L / 2 (t), the output signal of the potentiometer of the second measuring device 16, which is a measure for the height A? represents the loaded tobacco fleece 12, and
(Jo as Bczug'.vert, i.e. in this case the voltage of the recirculation, which corresponds to the height Λ - 0 when the two rollers are resting on the conveyor belt 10.

A pair of these voltages, i.e. U \ (t) and i / o on the one hand and £ / ₂ (t) and Uo on the other hand, are fed to an adapter stage 48 or 49, which essentially consists of a differential amplifier circuit. The two matching stages 48 and 49 form according to the equation

JU ₁ (O = K (Uo-U ₁ (O)

the respective useful signals AU \ (t) or AUi (0- These useful signals AU \ (0 or AUi (t) respectively represent the determined heights Ai and Aj of the tobacco fleece.

The actual determination of the compressibility is based on a differential measurement, one measured variable being the height A _{1 of the unloaded tobacco fleece 12 and the other measured variable being the height A 2 of} the tobacco fleece compressed by a load. The compressibility is defined as the height difference related to the height of the unloaded fleece according to the equation

Hi-

• 100%.

To carry out the calculation steps required for this, the useful signals AU \ (0 and AUi (0 are converted by voltage / frequency converters 50 and 51 according to the frequency modulation method into signals of the same amplitude and a frequency f (0 , which

so proportional to the respective useful signal i> \ downstream integrators 52 and 53, the oscillations of these signals are counted with the frequencies f \ (0 or / ₂ φ during a measuring time Tu . This measuring time can be varied as required.

The output signals Z 1 and Z _{2 of} the two integrators 52 and 53, which represent the respective heights Ai and hi in digital form, are sent to a programmable computer 60 via a multiplexer 56 and an interface 58.

Evaluation of the signals Z \ and Zz and thus its transmission through the multiplexer 56 must be synchronized to ensure that only the heights Ai and A ₂ are evaluated, are assigned to the same region of the tobacco mat 12th This time offset of the measurement signals, which is based on the fact that the two rollers 32 and 44 are attached one behind the other, is taken into account by an electronic time base 54. This time base 54 controls the integration on the one hand and

the feeding of the results via the multiplexer 56 to the computer 60 on the other hand.

The time sequence is shown in FIG. 5 can be seen.

FIG. 5 shows the 10 Hz cycle of the evaluation circuit and the delay time T, which is dependent on the speed of the tobacco fleece 12: s, between the two measurements; the delay time T _v can be expressed, for example, in | Set steps of 0.1 s taking into account the transport speed of the tobacco fleece 12. |

The measuring time Tm is in turn a multiple of the delay time Ty and can also be adjusted by changing the factor m.

As shown in Fig. 5, the measuring time 1 of the first device 14 begins at a specific point in time at which the height h \ of the unloaded i:> area of the tobacco fleece 12 is determined.

After the reference time T _n has elapsed from this point in time, this area of the tobacco fleece 12 has reached the second measuring device 16, so that it begins measuring the height hi of the loaded tobacco fleece in the measuring time 2. The time base 54 controls the beginning and the end of the measurement, that is to say essentially the two integrators 52 and 53.

The multiplexer 56 is also controlled by the time base 54 controlled and queries the two measurement results one after the other, so that they are based on a load pulse the computer 60 can be given. These load pulses synchronize the supply of the two Measurement results for the calculator.

The computer then determines the actual compressibility and according to the relationship given above prints out the result, for example.

In addition, it is possible} \ the production process to influence corresponding to a change of the compressibility of tobacco mat directly beispiels- 35 and J as the tobacco plug weight and temperature,

Moisture, as well as cutting width of the tobacco materials to ■;}

vary.

40

For this purpose 4 sheets of drawings! -I

50

55

60

Claims (1)

Patent claims: 1. Device for determining the compressibility of a transported over a flat surface Streams of cut tobacco materials a) with a first sensor for measuring the height of an unloaded area of the tobacco stream in a first place, b) with a second sensor to measure the height of a compressed air due to a defined load Area of the tobacco stream at a second location, and c) with a device for determining the compressibility from the difference between the two heights,