FR2493800A1 - METHOD AND DEVICE FOR CONTROLLING FILLING MATERIALS IN A FULLY-DOSED FILLING MACHINE - Google Patents

Abstract

EACH FILLING STATION OF THE FILLING MACHINE, ADVANTAGEOUSLY OF THE CARROUSEL TYPE, INCLUDES A PARALLELOGRAM SCALE EQUIPMENT8 WHICH THE BAFF12 IS MECANICALLY COUPLED BY A TRACTION CABLE28 TO THE SENSITIVE BLADE26 OF AN ENTRY SENSOR25 OF WHICH IS ADDRESSED TO A PROGRAMMABLE LOGIC UNIT WITH MEMORY33 PROVIDING AN OUTPUT SIGNAL35 TO THE FILLING HEAD6 WHEN THE VALUE OF THE MEASURED WEIGHT REACHES A DEDUCTED VALUE AND CORRECTED FROM THE NOMINAL VALUE REGISTERED IN THE LOGIC UNIT.

Description

1. The present invention relates to installations for

  container filling, and more particularly, a process

  dice and a filling material metering device

  containers in a filling machine with weighted dosage.

  The weighting dosage is more and more necessary in filling installations with liquid or divided materials,

  for example in the food or pharmaceutical industries

  due to the achievement of more precise results and

  more reliable compared to volume metering systems -

  stick. This technique requires the arrangement, for each filling head, of a weighing scale associated with detection means for controlling the filling head as a function of the weight of filling material actually delivered. Until now, due to the severe conditions of use of such equipment, provision has been made, associated with a mobile element of the balance, for a detection means of the proximity detection type, as described in the French patent.

  no 2.098.780 in the name of the inventor. This command technique

  by all or nothing gives full satisfaction with regard to

  does the robustness of the reliability of use but has the disadvantage of having to take into account and correct moreover fluctuating parameters of the filling installations, such as for example those relating to the calibration of empty containers or the weight of the column of material delivered between the 2. outlet of the filling head and the container, imposing

  the use of means of correction of the detectors of

  ximited as described for example in the patent application

  French No 78/1787 in the name of the plaintiff.

  The object of the present invention is precisely to propose a method and a device for metering material

  for filling containers in filling machines

  weighted age, obviating the above drawbacks,

  offering, while retaining high reliability in use

  tion, great flexibility of use by integrating

  programmable logical posers and allowing to modulate the

  operating conditions of the installation, either injected

  both imaige specific parameter data, either automa-

  tick during operation.

  To do this, the method according to the present invention

  tion, implemented in a compression filling machine

  with at least one filling / weighing station with one head

  filling, a weighing scale with parallel equipment

  logram, detection means being associated with the device

  weighing device to control the filling head, consists in mechanically coupling to a mobile element of the crew of

  the balance a force sensor and to transmit in a con-

  continues the sensor output signal to a logic unit

  memory grammar providing a control signal to the

  2nd filling head when the detected weight value reaches

  dyes a value deducted and corrected from the nominal value

registered.

  According to another characteristic of the present invention

  tion, the metering device for such a filling machine

  pleating, more particularly but not exclusively of the type

  with multi-station carousel, comprising at least one filling station

  pleating with a controllable filling head and a ba-

  weighing lance with parallelogram equipment, detection means being associated with the weighing scale to supply a control signal to the filling head, comprises a force sensor mechanically coupled to a mobile element of the equipment of the scale and connected to a first input of a 3. programmable logic unit with memory comprising a second control and storage input, and the output of which is

connected to the filling head.

  In addition to the problems of severe conditions of use

  As far as temperature and humidity are concerned, filling machines, particularly of the carousel type, have so far been rebellious against the integration of components.

  particularly due to the high levels of vibration

  tion in wide frequency ranges encountered in such

  machines. The plaintiff, with its experience of more than

  many years in the field of weight dosing, and following many experiences, realized that the use

  a force transducer, for example of the gauge type

  drag, could only be done in combination with a weighing scale with parallelogram crew, whose robustness and its ability to "absorb" parasitic couples inevitably

  induced on the measuring plate in large installations

  nevertheless allowed, thanks to the low inertia of

  these scales, equipped with articulation bearings, capacities

  extremely fine measuring tees, in particular in filling carousels, in addition to the inertial problems involved

  the rotary nature of the installation, the containers, for example

  full bottles, to be correctly positioned below the filling heads are dynamically placed during

  of their loading on the filling carousel by bri-

  centering, such as those shown in Figure 1

  and then transmit large and variable parasitic couples to the equi-

  weighing page which make it illusory due, in addition, to im-

  supporting the center of gravity of the container, a direct mechanical coupling between the receiving / weighing platform and a transducer

by force.

  According to another characteristic of the present invention

  tion, the force sensor being of the sensitive blade type and

  strain gauge, the mechanical coupling between the cap-

  tor and the moving part or bane of the balancing crew

  this is achieved by a pull cable.

  Indeed, due to the aforementioned vibration rates-

  4. born, the plaintiff has found that the exit signal

  of a transducer operating in compression was almost

  unusable in a filling machine, while the tensile stress, more particularly by a flexible cable, makes it possible to reduce with a factor of 10 the

  effects of vibrations on the sensitive sensor plate.

  Other features and advantages of the pre-

  invention will emerge from the following description of a

  embodiment given by way of illustration but in no way limiting, made in relation to the appended drawings, in which: FIG. 1 is a schematic sectional view of a weighing station of a filling metering carousel equipped with the device according to the present invention; and

  Figure 2 is a plan view of such an installation.

  filling lation making it possible to assess the sequences of the dosing control process with the device of the

figure 1.

  In Figure 2, we recognize a carousel

  multi-station pleating 1 supplied with containers to be filled by an upstream transfer carousel 2 picking up the containers 3 on a linear conveyor 4, the containers filled in the filling carousel 1 being removed from the latter and

  recirculated on the linear conveyor 4 by a

  output transfer rousel 5. The filling carousel

  ge 1 has a number of weighing stations (ty-

  pique 12 or 24) of the type shown in Figure 1.

  In this figure 1, we recognize the filling head

  sage 6, for example of the type with electric valve control

  genetic, arranged directly above a receiving plate 7 of a

  weighing balance of the parallelogram type, general

  referenced 8. The balance 8 consists of a support column 9, mounted on a frame 10 secured to the hollow shaft

  11 of the carousel, of a floating column 11, and of a flail

  lower 12, the parallelogram being completed by a cross

  is superior 13, these different elements being articulated with respect to each other by means of ball bearings such as 5.

  than that shown in 14. According to the present invention, the balan-

  this 8 has a particularly compact configuration, with the

  average height of the upper or double columns of the length

  qsurer of sleepers. The plate 7 is connected to the flow column-

  aunt 11 by a hollow tubular upright 15. According to one aspect of the present invention, to adjust the leveling of the weighing pan 7 with the

  tray 16 of the carousel, the upright 15 has its lower end

  lower bearing on a cam with evolutive surface 17 commanda-

  ble by a shaft 18, the upright 15 being fixed on the column

  floating 11, once leveled, by clamping plates 19. The various scales of the carousel 1 are traditionally housed in a casing comprising an upper cover 20 and an external peripheral skirt 21. To avoid projections of the filling materials at inside the casing, to the upright 15 of the plate 7 is associated a system of

  cylinder labyrinth 22, as shown in FIG. 1.

  The plate 7 is traditionally equipped with open flanges

  tes 23 for centering the receptacles, located, for the bottles

  them at the neck of these bottles and inducing the pro-

  blamed by the aforementioned parasitic couples. The crew of ba-

  lance 8 can be completed by a counterweight 24, mounted on an extension of the beam 12, although this counterweight induces

  couple problems: inertial requiring compensation

  mass on the other side of the scale, such a counter

  weight is not necessary with the force sensor according to the

present invention.

  The force transducer 25, comprising a sensitive blade 26 with a strain gauge, is mounted on a stirrup

  27, substantially in the extension of the upper crossmember

  re 13, the stirrup 27 being fixed by the inner ends

  from its lateral branches to the support column 9. Conform-

  ment to the present invention, this support column 9 is in

  additionally fixed to the frame 10 with the interposition of elastic elements

  as in elastomer 28, for example of the so-called "Silent-Block" type.

  The sensitive blade 26 of the sensor 25 is mechanically coupled to the outer end of the beam 12 by a cable 28 carrying 6.

  normally a pull on the sensitive blade in a di-

  rection perpendicular to the plane thereof. According to one aspect of the present invention, the cable 28 passes through the orifice of the sensitive blade 26 and a helical spring 29, at the upper end of which is connected the adjacent end.

  center of the cable 28, the spring 29 carrying by a cup

  spun on the blade 26. The spring 29 is of the long spoke type.

  Deur and designed to start to crush under the application of a compressive force of about 20 kg, that is to say much greater than the normal weight of the filled containers

  to be weighed by the balance. For custom container weights

  rer of the order of 2 to 5 kg, the sensor 25 is chosen with a

  sensitive blade of the 20 kg class. To avoid all-

  accidental damage to the sensitive blade, the downward angular movement of the beam 12 is limited by a stop

adjustable 30.

  According to the present invention, the output of the

  force sensor 25 is routed through a line 31 to a

  measurement port 32 of a programmable micro logic unit

  processor 33, housed in a support with shock absorber

  below the balance crew 8. The logic unit with memory-

  re 33 includes at least a second input 34, allowing

  injecting certain data into memory and entering it

  No specific program steps. A calculation output 35 of the logic unit 33 is connected by a line 36, to the head

  filling 6, to selectively control the opening.

  and closing according to conditions developed by the uni-

  logic tee 33, typically when the measured weight value

  by the sensor, converted to digital, reaches an in-

dull displayed.

  The dosage control method according to the present

  invention will now be explained in more detail with reference to

  Refer to the layout diagram in Figure 2. At the beginning

  of a filling cycle, the data specific to this cycle, no-

  particularly the desired weight values according to the type of pro-

  lines to be filled and the dimensions of the containers are injected

  input 34 into the logic units 33 of the balan-

7.

  these different filling stations of the carousel 1. Sup-

  for example, assume that the desired weight of the replacement material

  pleating of the container is 1000 grams. With the process

  of the invention, we are not concerned to carry out beforehand

  ble an average determination of the tares of the refill containers

  fold no more than the average value of the column of li-

  quide or divided product mentioned in the introductory part

  description. We just assign in units

  logic 33 an initial desired value less than the weight

  required, for example 900 grams. A first passage of reci-

  pients supplied by the linear conveyor 4, allows, for successive filling stations, the associated sensors 25 to transmit to the corresponding logic units 33, during the first angular transfer phase AB from the loading area A, (angle AB of l '' from 15 to 200), measurement signals making them take into account the weight of

  the tare consisting of each container, which allows

  wedge the registers of logic unit 33 to make it ef-

  make a continuous measurement in net weight during the angular transfer phase B-C upstream of the unloading area

  D, i.e. before structural elements of the carrou-

  transfer salt 5 do start to come into contact with

  containers. The angle C-D is chosen on the order of 10 to 150.

  As a function of the deliberately reduced calibration of this start-up cycle, the logic unit 33 will have supplied, by its output, a signal for closing the head 6 when the value detected by the sensor 25 - shifted from the initial taking into account of the calibration. - will have reached 900 grams, and this, upstream of the angular zone C. Once the command of the head 6 has been carried out, the logic unit 33 records the actual weight

  of the filled container, and during the angular transfer phase

  re empty D-A, performs the comparison with the desired value

  recorded to correct it, thus taking into account the

  meters specific to the filling cycle considered, such as the

  material column weight or impact force of it

  ci according to the filling rate, so that the main value

  is taken into account in the following cycle to order the 8. closing head will be different from the exact desired value and from the value initially displayed to provide, from this second cycle, the calibration offset being effected each time during the AB transfer , the exact weight required, in this case 1000 grams to + 5 grams.

  The method according to the present invention allows in or

  be to take into account unwanted quantities of material

  on the trays 7, for example from leaking containers

  previous clients and to activate, via an output 37, a device

  positive alarm and / or display, signaling the malfunction of a head as detected during the phase

  of comparison in the angular transfer phase D-A.

  Although the present invention has been described in

  lation with particular embodiments, it is not limited thereto but is on the contrary susceptible to modifications and variants which will appear to the man

art.

9.

Claims (8)

  1 - Method for controlling the metering of container filling material in a filling machine   weighted dosage, comprising, in at least one filling station   sage, a filling head, a parallelogram weighing scale and associated detection means   on the scale to selectively control the filling head   wise, characterized in that it consists in mechanically coupling   ment to a mobile element (12) of the balance (8) a force sensor (25, 26) and to continuously transmit the signal from the sensor to a programmable logic unit with memory (33)   providing a control signal (35) to the filling head   wise (6) when the detected value of the weight reaches a value   deducted from them and corrected by a recorded nominal value.   2 - Method of dosing control according to the claim   cation 1, in a multi-station filling carousel supplied   tee in containers to be filled in a loading area and   vrant containers filled in an unloading area, characterized in that it comprises the steps of performing a   taking into account by the logical unit (33) of the tare of the container   be able to weigh over an angular range <A-B) from the loading area (A) before giving the opening order of the filling head (6).   3 - Method of dosing control according to the claim   tion 2, characterized in that at the start of a filling cycle   wise, it also includes the step of performing in the logic unit (33) during the angular empty path, between the zone   of unloading (D) and the loading area (A), a compa-   reason between the value of the measured effective weight of a reci-   pient filled just discharged and face value   saved to correct it.   4 - Device for controlling the metering of container filling material in a filling machine   weight dosage, comprising, in at least one filling station   sage, a filling head, a balanced weighing scale   parallelogram page and detection means associated with the weighing balance to provide a control signal to 10. the filling head, characterized in that it comprises a   force sensor (25, 26) mechanically coupled (28) to an element.   movable ment (12) of the balance (8) and whose electrical output (31) is connected to a first input (32) of a programmable logic unit with memory (33) comprising a second input (34) for controlling addressing and storage and whose   calculation output (35) is connected to the filling head (6).   - Device according to claim 4, characterized in that the sensor (25) is of the blade type sensitive to   strain gauge (26), the mechanical coupling between the cap-   tor (25) and the movable element (12) of the balance (8) being   produced by a traction cable (28).   6 - Device according to claim 5, character-   se in that the coupling between the sensitive blade (26) of the cap-   tor (25) and the adjacent end of the cable (28) is   by means of a calibrated spring with high stiffness (29).   7 - Device according to any one of the claims   tions 4 to 6, characterized in that the balance (8) comprises a cam adjustment device (17, 18) with which the upright (15) supporting the platform (7) of the balance cooperates for adjusting the level of the plateau.   8 - Device according to any one of the claims   cations 4 to 7, for multi-station filling carousel, ca-   characterized in that the support column (9) of each crew   balance (8) is mounted on the rotating frame (10) of the carrou-   salt with interposition of elastic damping elements (28).   9 - Device according to claim 8, wherein the scales of the different filling stations are housed in a protective casing, characterized in that it comprises a cylinder labyrinth system (22) at the   crossing of the casing (20) by the upright (15) plate support sheet (7).   - Device according to any one of the claims   cations 4 to 9, characterized in that it comprises an alarm and / or display device connected to a second output (37) of the logic unit (33).