Abstract:
A filling machine for filling containers with a liquid filling material, the filling machine includes a transport element with filling elements arranged thereon, each forming a filling point for filling a container. Each filling element has a housing having a discharge opening, a channel formed in the housing. The channel connects to a product line to supply the filling material, and a liquid valve, a measurement system provided separately for each filling element for determining filling level, filling material quantity, or filling material volume in a container, a controlled gas path associated with each filling element, and a control valve fitted to the controlled gas path. At least two filling points and their filling elements define a function-and-process unit, and a control valve is provided in common for a gas path of all filling elements of a function-and-process unit.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is the national phase under 35 USC 371 of international application no. PCT/EP2011/002501, filed May 19, 2011, which claims the benefit of the priority date of German application no. 10 2010 032 573.2, filed Jul. 28, 2010. The contents of the aforementioned applications are incorporated herein in their entirety. 
     FIELD OF DISCLOSURE 
     The invention relates to a filling machine. 
     Filling machines for filling bottles or similar containers, in particular for pressure filling and/or pressureless filling of bottles and similar containers in which the containers are arranged lying tightly against the respective filling element, are known in various embodiments. 
     BACKGROUND 
     The term “pressure filling” in the sense of the invention generally means a filling method in which the container to be filled lies tightly against the filling element and usually before the actual filling phase, i.e. before opening of the liquid valve, is pre-tensioned via at least one controlled gas path formed in the filling element with a compressed tension gas (inert gas or CO2 gas) which then during filling is increasingly displaced from the container interior as a return gas, also via at least one controlled gas path formed in the filling element, by the filling material flowing into the container. This pre-tension phase can be preceded by further treatment phases, for example an evacuation and/or flushing of the container interior with an inert gas e.g. CO2 gas etc., also via the gas paths formed in the filling element. 
     The term “pressureless filling” in the sense of the invention generally means a filling method in which the container to be filled lies preferably with its container mouth also tightly against the respective filling element and the container interior, before the actual filling phase i.e. before opening of the liquid valve, is pre-treated for example evacuated and/or flushed with an inert gas for example CO2 gas via controlled gas paths formed in the filling element, wherein then during filling the gas increasingly expelled by the filling material flowing into the container is discharged from the container interior as a return gas via at least one controlled gas path formed in the filling element. 
     “Containers lying tightly against the filling element” in the sense of the invention means that the container to be filled lies in a manner known to the person skilled in the art with its container mouth tightly against the filling element or pressed against the seal present there and surrounding the at least one discharge opening of the filling element. 
     “Containers” in the sense of the invention are in particular cans and bottles of metal, glass and/or plastic, but also other packing means which are suitable for filling with liquid or viscous products for pressure filling or for pressureless filling. 
     The term “substantially” in the sense of the invention means deviations from the precise value by +/−10%, preferably by +/−5%, and/or deviations in form of changes irrelevant to function. 
     In known filling machines, in particular those of circulating design in which the filling points are provided on a transport element in the form of a rotor that can be driven circulating about a vertical machine axis, the filling elements each have several controllable gas paths each with at least one control valve per gas path, for example three such control valves, to achieve a high flexibility for the filling machine i.e. in order in particular to allow different filling methods optimally adapted to the respective product such as pressure filling, pressureless filling etc. with different treatment phases, in particular also with different pre-treatment and post-treatment phases, such as for example evacuation and/or flushing of the respective container interior before opening the liquid valve, and/or settling of the filling material and/or pressure relief of the container interior after closing of the liquid valve etc. The plurality of control valves means a substantial complexity in construction, assembly and control technology. 
     SUMMARY 
     The object of the invention is to provide a filling machine which, without loss of flexibility with regard to different filling methods and without loss of quality of the filling process, allows a substantial reduction in the complexity in construction, assembly and control technology. 
     The filling machine according to the invention is characterised in that in each case at least two filling points having one filling element are combined into one function or process unit, wherein the at least one controlled gas path or the at least one control valve of this gas path is provided in common for the filling elements of each function and process unit and is controlled in common by the machine controller of the filling machine. Each filling point or each filling element is however equipped with an independent measuring system, in particular to detect the filling height in the respective container and/or the filling material quantity introduced into the respective container and/or the weight of the respective container, and to control the filling element or its liquid valve as a function of the measurement signal from the measurement system. The measurement system is for example a sensor or a return gas pipe to detect and adjust the filling height, a volume or flow meter device to detect the filling material quantity, and/or a weighing cell to detect the weight. 
     The design according to the invention not only reduces the number of control valves necessary by at least 50% in comparison with conventional filling machines, but achieves a substantial reduction in the control technology complexity and the assembly and maintenance complexity, in particular taking into account the circumstance that in the filling machines conventional today, each filling element has at least three controlled gas paths each with three control valves. 
     At each individual filling point are provided a container carrier and for example a curve-controlled lift device with which a controlled relative movement is possible between the container carrier and the filling element, preferably a movement of the container carrier is generated relative to the filling element, namely to press the respective container tightly against the filling element and to release the filled container from the respective filling element. The lift devices are for example provided separately for all filling elements or filling points of the filling machine or preferably common to the filling elements or filling points of each function and process unit, which in particular for container carriers for suspended holding of containers (e.g. PET bottles) on a container flange (neck ring) provided below the container opening, leads to further simplification of the filling machine in particular in relation to construction and control technology. 
     Refinements, advantages and possible applications of the invention arise from the description below of embodiment examples and from the figures. All features described and/or shown in the figures alone or in arbitrary combination are in principle the object of the invention irrespective of their summary in the claims or back reference. The content of the claims is also declared an element of the description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention is explained in more detail below with reference to the figures with embodiment examples. These show: 
         FIG. 1  in highly schematic depiction and in top view, a filling machine of circulating type with a plurality of filling points arranged on the periphery of a rotor that can be driven circulating about a vertical machine axis; 
         FIG. 2  two successive filling points in the direction of rotation of the rotor, forming a function and process unit; 
         FIG. 3  in schematic perspective view, a filling machine of circulating type corresponding to a further embodiment of the invention; 
         FIG. 4  two filling points arranged in different filling levels on the filling machine in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     The filling machine designated generally as  1  in  FIGS. 1 and 2  serves to fill containers in the form of bottles  2  with a liquid filling material and is formed as a filling machine of circulating type with a rotor  3  that can be driven circulating about a vertical machine axis in the direction of arrow A. This rotor on its peripheral region has a plurality of filling points  4  and  4   a  which are there provided distributed around the machine axis at even angular and pitch intervals such that in the rotor rotation direction A, a filling point  4  is always followed by a filling point  4   a  and a filling point  4   a  is always followed by a filling point  4 . In each case one filling point  4  and one filling point  4   a  form a function and process unit  5  to be described in more detail below. In the embodiment shown, the filling point  4  precedes the filling point  4   a  in each function and process unit  5  in relation to the rotor direction of rotation A. 
     The empty bottles to be filled are each supplied individually to the filling points  4  and  4   a  at a container inlet  3 . 1  formed for example by a transport star. The filled bottles  2  are taken from the filling points  4  and  4   a  via a container outlet formed for example by a transport star, as indicated by arrows B and C in the  FIG. 1 . 
       FIG. 2  shows two filling points  4  and  4   a  forming such a function or process unit  5 , of which the filling point  4  substantially comprises a filling element  6  and a container carrier  7 , and the filling point  4   a  substantially comprises a filling element  6   a  and a container carrier  7   a . The container carriers  7  and  7   a  in the embodiment shown are designed such that the respective bottle  2  is held with a bottle or neck flange suspended on the container carrier  7  or  7   a , namely with its bottle axis coaxial with a vertical filling element axis FA. The two container carriers  7  and  7   a  in the embodiment shown can each be moved curve-controlled up and down in the direction of filling element axis FA, namely between a lowered state at container inlet  3 . 1  to receive the bottle  2  to be filled and at a container outlet  3 . 1  for discharge of the filled bottle  2 , and a raised state in which the respective bottle  2  is raised during the filling process with its bottle mouth lying tightly against the filling element  6  or  6   a.    
     In the embodiment shown the lift movement of all container carriers  7  and  7   a  and hence also the container carriers  7  and  7   a  of each function and process unit  5  is controlled individually by curve rollers  8  which cooperate with a control curve not shown which does not circulate with the rotor  3 . 
     The filling elements  6  and  6   a  are formed identical apart from the differences to be described below. In detail the filling element  6  comprises a liquid channel  10  formed in a filling element housing  9 , which channel at its upper region is connected via a product line  11  with a boiler  12  common to all filling elements  6  and  6   a  of filling machine  1 . During the filling operation, the boiler  12  is partly filled with the liquid filling material so that in the boiler  12 , a gas chamber  12 . 1  is formed above the filling material level and a fluid chamber  12 . 2  below this level into which the product line  11  opens. 
     In the product line  11  of each filling element  6  and  6   a  is arranged an independent flow meter  13 , the signal from which controls the precise quantity or volume filling of the bottles  2 . On the underside of the filling element housing  9 , the liquid channel  10  forms a discharge opening  14  to discharge the liquid filling material into the respective bottle  2  which is arranged with its bottle opening lying tightly against the filling element  6  via a seal not shown which surrounds the discharge opening  14  in a ring-like manner. 
     In the liquid channel  10 , before the discharge opening in the flow direction of the filling material, is arranged a liquid valve  15  with a valve body  16  cooperating with a valve surface on the inner face of the liquid channel  10 , which valve is provided on a return gas pipe  17  acting as the valve tappet and with this return gas pipe  17  via an activation device  18  can be moved under control up and down to open and close the liquid valve  15  in the direction of filling element axis FA. 
     The return gas pipe  17  protruding downwards with its lower open end above the annular discharge opening  14  is a common component of several controllable gas paths formed in the filling element housing  9  with which the upper, also open return gas pipe  17  extending into a closed chamber  19  is connected via this chamber. 
     In the embodiment shown each filling element  6  has three controlled gas paths each with one control valve (gas cylinder)  20 ,  21 ,  22  which controls the respective gas path and is preferably activatable pneumatically. Via the gas path containing the control valve  20 , when the control valve  20  is open the return gas pipe  17  is connected with a ring channel  23  common to all filling elements  6  and  6   a  on the rotor  3 , which via at least one line  24  is connected to the gas chamber  12 . 1  of the boiler  12 . Via the gas path containing control valve  22 , when the control valve  22  is open the return gas pipe  17  is connected with a ring channel  25  common to all filling elements  6  and  6   a  on the rotor  3  which e.g. serves on filling as a pressure relief channel (in pressure filling) to relieve the pressure after filling or as a vacuum channel to evacuate the bottle  2  before filling etc. With the gas path containing the control valve  21 , when the control valve  21  is open, the return gas pipe  17  is connected choked with the ring channel  25  for example for slow pressure relief of the filled bottle  2  or for slow residual filling or braked filling of the respective bottle  2 . Evidently the number of controlled gas paths and hence the number of control valves  20 - 22  can also be greater than three. 
     The filling elements  6   a  are designed identical to filling elements  6  but so that the controllable gas paths formed in the filling element housing  9  of the filling element  6   a  are part of the controllable gas paths of the respective allocated filling element  6  of the function and process unit  5 , i.e. control valves  20 - 22  are provided only once for both filling elements  6  and  6   a  of each function and process unit  5 , namely in the embodiment shown on the respective filling element  6 . Consequently the gas paths of both filling elements  6  and  6   a  of each function and process unit  5  are controlled in common. Each filling element  6   a  is however connected to the boiler  12  via its own product line  11  with its own flow meter  13 . 
     The opening of the liquid valve  15  of the two filling elements  6  and  6   a  for each function and process unit  5  takes place for example at the same time for example by corresponding control of the activation devices  18 . Without great control complexity however the opening of the liquid valve  15  of the filling element  6   a  can take place with a time delay, for example with a time delay of 100 milliseconds, in relation to the opening of the liquid valve  15  of filling element  6  in each function and process unit  5 . The closing of the liquid valve  15  on both filling elements  6  and  6   a  of each function and process unit  5  takes place individually controlled by the flow meter  15  or by another measurement or sensor element assessing the filling height in the bottles  2  and/or the quantity of filling material introduced into the bottles  2 , for example by a sensor to determine the filling height, by an extended return gas pipe, by a weighing device etc. 
     The control valves  20 - 22  common to the controlled gas paths of the filling elements  6  and  6   a  of each function and process unit  5  lead to a substantial reduction in constructional complexity, production costs and control technology complexity by reducing the number of necessary control valves  20 - 22  on the filling machine by at least 50%. The design according to the invention also allows a reduction in the angular or pitch interval between the filling points  4  and  4   a  and hence an increase in the number of filling points for the same rotor diameter. Thus for example with a filling machine for filling materials containing CO2 e.g. for filling beer, for the conventional rotor diameter the number of filling points can be increased by at least 10%. 
     The filling elements  6  and  6   a  are suitable for different filling methods, for example for pressure filling of the bottles  2  with the liquid filling material with pretensioning of the bottles  2  before opening of the liquid valve  15  with a tension gas under pressure from the ring channel  23  or the gas chamber  12 . 1  of the boiler  12 , but also for pressureless filling in which the gas chamber  12  also filled with inert gas is exposed to ambient pressure or a pressure slightly above ambient pressure. 
     Depending on the filling method concerned, the controlled gas paths with control valves  20 ,  21  and  22  serve to perform the common control e.g. of the phases of evacuation, pretension, settling and pressure relief in the filling process at both filling elements  6  and  6   a  of each function and process unit  5 , namely with the process times stored in the machine controller or in the computer there which apply to both filling elements  6  and  6   a  of the same function and process unit  5 . 
     It has been assumed above that the lift movement of all container carriers  7  and  7   a  is controlled individually. For further simplification and reduction in particular of the constructional complexity and for further reduction of the pitch interval of the filling points, it is also possible to raise and lower the container carriers  7  and  7   a  of each function and process unit  5  with a common lift device. 
       FIGS. 3 and 4  show diagrammatically a filling machine  1   a  which differs from the filling machine  1  substantially only in that the filling points  4  and  4   a  on rotor  3   a  are provided in two filling levels FE 1  and FE 2  offset in relation to each other in the direction of the vertical machine axis, namely filling points  4  and  4   a  are again provided in each filling level FE 1  and FE 2 , for example such that below each filling element  6  of the upper filling element level FE 1  is a filling element  6  of the lower filling element level FE 2 , and below each filling element  6   a  of the upper filling level FE 1  is a filling element  6   a  of the lower filling level FE 2 . 
     The bottles  2  to be filled are supplied to the filling machine  1   a  or filling points  4  and  4   a  in two levels via container inlets  3   a . 1  there. The filled bottles  2  are also removed from filling points  4  and  4   a  on two levels at container outlets  3   a . 2 . As in the filling machine  1 , the filling points  4  and  4   a  forming a function and process unit are provided successively in each filling level FE 2  and FE 1  in the direction of rotation A of rotor  3   a , wherein at least the liquid valves of filling elements  6  and  6   a  of each function and process unit are controllable individually, while the control valves  20 ,  21 , and  22  for the filling elements of each function and process unit are again provided in common. The container carriers  7  and  7   a  of each function and process unit can be moved either individually or in common relative to the respective filling elements  6  or  6   a.    
     One filling element  6  and  6   a  of filling level FE 1  and one filling element  6  or  6   a  of filling level FE 2  are each connected via their product line  11  to a common product line  26  leading to the fluid chamber  12 . 2  of the boiler  12 , in which line is provided the flow meter  13 , in this embodiment common for filling elements  6  and  6   a  of both filling levels FE 1  and FE 2 . A preferably adjustable choke  27  arranged in the product line  11  of the lower filling level ensures that despite the height difference in filling levels FE 1  and FE 2 , the filling material quantity flowing per time unit to the lower filling element  6  and  6   a  when the liquid valve  15  is open is the same as the filling material quantity which flows to the upper filling element  6  or  6   a  when the liquid valve  15  is open. By use of the common flow meter  13 , not only the opening but also the closing of the liquid valves  15  of the two filling elements  6  and  6   a  arranged above each other takes place simultaneously triggered by a measurement signal generated by the flow meter  13  when the quantity of filling material detected by the flow meter  13  is equal to twice the filling material quantity to be introduced into each bottle  2 . In principle however it is possible to provide a separate flow meter  13  for each filling element  6  and  6   a  in each product line  11 , or to detect individually with other measurement or sensor means the filling height achieved in the respective bottle and/or the quantity of filling material introduced into the respective bottle, and thus control individually the liquid valves  15  of the filling elements  6  or  6   a  arranged above each other, i.e. to close them individually on reaching a desired filling material height or quantity. 
     The invention has been described above with reference to embodiment examples. It is evident that numerous changes and derivations are possible without leaving the concept fundamental to the invention. Thus it is possible for example that the control valves controlling the gas paths of the filling elements  6  and  6   a  of the respective function and process unit  5  or  5   a  are provided not on one of the filling elements or the filling element housing  9  there, but at a separate control block. 
     It has been assumed above that the filling elements  6 ,  6   a  allocated to each other and forming a function and process unit  5 , even in the embodiment shown in  FIGS. 3 and 4 , are arranged in a common filling level FE 1  and FE 2 . In principle however it is possible that the allocated filling elements  6  and  6   a  are provided in different filling levels, for example the filling elements  6  in the upper filling level FE 1  and the filling elements  6   a  in the lower filling level FE 2 , for example such that below each filling element  6  is provided the allocated filling element  6   a , wherein again the upper filling element  6  and the lower filling element  6   a  form a function and process unit  5  at which the control valves  20 - 22  for the gas paths are provided in common. 
     LIST OF REFERENCE NUMERALS 
     
         
           1 ,  1   a  Filling machine 
           2  Bottle 
           3 ,  3   a  Rotor 
           4 ,  4   a  Filling point 
           5  Function and process unit 
           6 ,  6   a  Filling element 
           7 ,  7   a  Container carrier 
           8  Curve roller 
           9  Filling element housing 
           10  Liquid channel 
           11  Product line 
           12  Boiler 
           13  Flow meter 
           14  Discharge opening 
           15  Liquid valve 
           16  Valve body 
           17  Return gas pipe 
           18  Activation device 
           19  Chamber 
           20 - 22  Control valve 
           23  Ring channel 
           24  Line 
           25  Ring channel 
           26  Product line 
           27  Choke 
         A Rotor direction of rotation 
         B Bottle supply 
         C Bottle discharge 
         D Lift movement of container carrier  7  or  7   a    
         FA Filling element axis