Packing machine method for packing food product and adapting pressure in compression region of pump

Abstract

To provide a packing machine that enables improved continuous packing of packed materials having different compressibility, and a corresponding method.SOLUTION: The present invention relates to a packing machine for packing packed materials, in particular, a food product, using a pump 1 comprising an inlet region 9, a compression region 11 and an outlet region 17, the packing machine further comprising a first pressure sensor 41 for measuring the pressure in the compression region 11 and an adjustment device for regulating different pressures in the compression region 11. The present invention also relates to a method for packing packed materials using a corresponding packing machine.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a filling machine and a method for filling food products and adapting the pressure in the compression area of ​​a pump, according to the prerequisites of claims 1 and 12.

[0002] Filling machines are used for filling filling materials, in particular food products. For example, as is clear from FIG. 1, food products such as sausage meat or pasty substances for vegetarian or vegan products are filled into a funnel 101 and discharged through a stuffing tube 102 via a conveying mechanism. When producing portioned food products such as sausages, quality and consistency on the one hand and quantity accuracy on the other hand are very important. It is therefore important that a uniform flow of filling material is formed and that the filling material strands have as uniform a density as possible, so that individual portions of the same weight and of the same quality and consistency can be produced.

[0003] For example, in addition to a proper filling of the pump's delivery chamber, it is also important to prevent pulsations in the discharge of the filling material, as described in EP 0718497 B1, EP 0583721 B1 and EP 2532244 A1, which are caused by a pressure difference between the pump's outlet and the open delivery chamber, i.e. between the compression and outlet regions of the pump.

[0004] Different pressures may prevail at the pump outlet, determined mainly by the type of product (viscosity, chunkiness, cohesion, compressibility, etc.), the pump filling speed and the processing equipment connected to the pump, resulting in pressure losses. These include pipes, deflections, filling flow dividers, etc. This processing equipment cannot be detected by the filling machine, so the machine control has no information in this regard and cannot take into account the corresponding parameters that affect the pressure.

[0005] If the pressure in the compression region, e.g. the delivery chamber, is selected to correspond to the pressure in the outlet region of the pump, an ideal pressure balance will result and pulsation can be effectively prevented. If there is a pressure difference between the compression region and the outlet region of the pump, a sudden backflow (P compression <P outlet ) or forward flow (P compression >P outlet ) occurs.

[0006] Attempts have already been made to effectively minimize pulsation. Pumps for delivering filling materials, for example flowable, pasty or lumpy food substances, for example rotary vane pumps, comprise an inlet area, where the filling material enters the pump, for example through a funnel as shown in FIG. 1, a compression area, where the volume in the conveying chamber decreases in the direction of rotation or in the direction of movement, respectively, and an outlet area. The compression area is arranged between the inlet and outlet areas. Attempts have already been made to limit the compression pressure in the compression area acting on compressible or incompressible media. For example, spring-loaded pressure relief valves, as described in EP 0 718 497 B1, are used for this purpose together with a compensation piston. If the pressure rises above a certain value, the excess product can be discharged via the pressure relief valve, for example into a return channel, which the compensation piston opens on actuation, in the direction of the pump inlet. This means that the pressure cannot be increased any further, or can only increase slightly. The prior art also includes weight compensation by means of a storage cylinder without a return channel, as disclosed, for example, in EP 0 583 721 B1.

[0007] For example, the pressure relief valve and the resulting compression are then adapted once to the air content of the particular filling material. The opening pressure of the compensation piston of the pressure relief valve is therefore selected to suit the desired protection of the product, leakage in the delivery mechanism and pressure at the pump outlet. The compression pressure in the prior art is therefore set to a specific value, i.e. is statically defined and established by using a spring with a specific spring constant / spring characteristics and a preload geometrically determined by the installation space. The device is configured such that when the opening pressure is exceeded, excess filling material can be returned, for example via a bypass channel, to a downstream conveying chamber of the inlet region.

[0008] As is apparent from figure 1, the filling material is delivered in a sausage meat trolley and filled into a funnel 101. It may happen that various batches are different, i.e. exhibit different compressibility, chunkiness, air content etc.

[0009] The pressure set in the compression zone for salami meat is not suitable for example for white sausage meat or for the pasty substances of vegan products. However, even with the very same filled product, variations in compressibility can occur depending on the batch, which in the first place leads to quality problems and weight variations.

[0010] Systems that set the opening pressure of the pressure relief valve to a constant value cannot accommodate such changes.

[0011] Different compressibilities beyond that would result in, for example, a pressure difference between the compression area and the outlet area accompanied by pulsation and thus weight variations of the strands of filling material and, as a result, reduced weight accuracy of the individual portions, e.g. sausages.

[0012] According to the Prepackaged Packaging Ordinance (FPackV), the weight stated for a prepackaged product may only be undercut to a small extent, such that the weight or mass of the portion is a certain amount, e.g. 1 g, above the stated weight, to be on the safe side, so that, for example, compressibility variations do not result in the stated weight being undercut. This leads to huge losses of filling material. In the case of a production of 200,000 portions with a total weight of 10 t per day, the losses are in the range of 200 kg, which means huge economic losses.

[0013] In the prior art, different pressure relief valves were installed for different filling materials or manual mechanical adjustments were made, which required stopping the machine. This does not compensate for fluctuations during processing. Furthermore, precise adjustment or adaptation of the pressure in the compression and outlet areas is not possible. In this regard, continuous and reliable operation is not possible.

[0014] Starting therefrom, the invention aims to provide a filling machine and a corresponding method which allow improved continuous filling of filling materials with different compressibility.

[0015] According to the invention, this object is met by the features of claims 1 and 12.

[0016] The filling machine for filling filling material, in particular food products, according to the invention comprises a pump with an inlet area, a compression area and an outlet area. The compression area is arranged separately between the inlet area and the outlet area. The filling machine is especially adapted for filling compressible media such as pasty substances, in particular pasty substances for sausage meat, vegan products, but also dough. In the compression area, the filling material fed through the inlet area is conveyed by a conveying element in a direction towards the outlet area, compressed and extruded from the pump through the outlet area, for example into a stuffing tube for producing sausages.

[0017] According to the invention, the filling machine comprises a first pressure sensor for measuring the pressure in a compression area, for example in at least one conveying chamber. This allows the pressure in the compression area to be detected. The sensor is preferably configured to measure a pressure that substantially corresponds to the pressure in the conveying chamber before the conveying chamber opens to the outlet area. The compression area can comprise a first area in which a volume of the filling material is compressed so that a corresponding pressure is established, and a downstream area (for example downstream in the direction of rotation in the case of a vane pump or downstream in the direction of transport in the case of an auger pump) in which no further compression takes place but the pressure is substantially maintained. The pressure in the compression area can for example be set to be equal to or greater than the pressure in the outlet area. For example, as mentioned above, a higher pressure in the compression area can be set to compensate for pressure drops due to leakage.

[0018] A pressure sensor, pickup or probe is therefore understood to be a device for detecting pressure, the detected measurement variable being converted into a corresponding electrical signal. For example, the following devices can be used as pressure sensors: piezoresistive sensors, strain gauge-based pressure sensors, inductive or capacitive pressure sensors, etc.

[0019] The sensor can also be integrated, for example, in the regulating device. The pressure or pressure changes can be detected by the drive, in particular a linear actuator or a spindle drive, respectively, by open-loop control evaluation of the drive current during movement or, for example, the holding current when the piston is at rest. The drive current increases as the pressure increases. This means that a separate pressure sensor can be saved. The sensor can be pre-calibrated accordingly.

[0020] The invention further comprises an adjusting device for adjusting the different pressures in the compression zone, i.e. for adjusting during production, without machine idle time and without interrupting production.

[0021] The pressure in the compression zone is measured continuously or at regular intervals and is set continuously or at regular intervals to a specific pressure value during production, which pressure value can be changed. In contrast, in the prior art, for example, where pressure relief valves statically set to a predefined pressure are used, adaptation during production, in particular continuous adaptation, and continuous and dynamic adjustment of different pressures during production is not possible.

[0022] According to the invention, by adapting the pressure in the compression zone, it is possible to respond in a quick and simple manner to changing process conditions and variations (e.g. different air contents in the food products and the associated different compressibilities). The respective pressures in the compression zone can be measured and set to values ​​suitable for different filling materials.

[0023] Defined conditions can be set in the compression area so that it is possible to react to changing pressures in the outlet area, for example to prevent pulsations. Pressure sensors and regulators in the compression area can therefore ensure greater portioning accuracy, i.e. weight accuracy per portion, and ultimately more economical production. In addition, the pressure can be adjusted in particular to vary the filling material, so that mechanical stresses on the filling material are prevented by excessive pressure in the compression area. In particular, it is possible to set the maximum possible pressure for different filling materials depending on the air content and the type of product.

[0024] The pressure can be dynamically set by means of a regulating device, where dynamic regulation is understood to mean regulating different pressures by means of a controllable regulating device which performs a corresponding action.

[0025] According to a preferred embodiment, the filling machine comprises a second pressure sensor in the outlet region for measuring the pressure in the outlet region, which, if known, can be adapted to the pressure in the compression region by means of a regulating device, for example by an operator or in particular by a respective control device arranged to control the pressure in the compression region in a closed-loop manner as a function of the pressure measured in the outlet region, with the pressure in the compression region being preferably the controlled variable and the pressure in the outlet region being the reference variable.

[0026] The respective control device has the advantage that the pressure in the compression zone can be adjusted continuously and dynamically to the pressure in the outlet zone during production, so that no pulsations occur, for example in the case of variations in the air content in the filling material or in the case of changes in the filling material, and therefore the operator can always assume that the pressure conditions are correct, which occurs automatically, for example in the case of changes in the delivery rate, i.e. the delivery rate per hour of the pump.

[0027] The pressure in the compression region is also preferably a controlled variable, and the pressure in the exit region is preferably a reference variable.

[0028] The control device is preferably configured such that the pressure in the compression region is controlled in a closed-loop manner as a controlled variable X, the actual value being the pressure measured by a first pressure sensor and the setpoint value being the pressure measured in the outlet region by a second pressure sensor, and the actuator being a regulating device.

[0029] According to a preferred embodiment, the regulating device is configured as a pressure limiter, so that if the target pressure in the compression region is exceeded, the excess volume is discharged from the compression region, in particular from the conveying chamber, for example through a discharge line, for example to an inlet region, or delivered to a compensation cylinder, which can receive the excess volume and optionally return it, for example, to a downstream conveying chamber (seen in the direction of rotation), in which case a volume sufficient to be able to establish an appropriate pressure, i.e. in particular the target pressure, is delivered.

[0030] According to a preferred embodiment, the target pressure in the compression zone is dynamically adaptable, i.e. variable, and therefore does not have to be constant. The target pressure can, for example, correspond to the opening pressure of a regulating device (e.g. a pressure relief valve that opens at a constant pressure). This opening pressure is therefore also variable, i.e. dynamically adjustable, and can change during production, which was not possible in the prior art.

[0031] The regulating device is advantageously configured as a valve. It can be, for example, a valve that can be controlled by the control device, opens if the measured pressure in the compression area is too high, discharges a sufficient amount of volume until the correct pressure is established, and then, for example, closes again. According to a particular embodiment, the valve is a pressure relief valve that can be integrated in a simple manner in the compression area and opens when a target pressure is exceeded. The regulating device can also comprise a compensation cylinder with a compensation piston, where, when the target value is exceeded, the excess volume is discharged into the compensation cylinder, and, for example, the compensation piston is returned into the compensation cylinder until the corresponding volume is discharged in order to set a corresponding target pressure.

[0032] The pressure sensor in the compression region communicates with the conveying chamber of the pump, for example the conveying chamber of a rotary vane pump, or the conveying chamber, i.e. the conveying auger of an auger pump or twin auger pump, in which the compressed fill material is placed.

[0033] The regulating device is preferably configured as a pressure relief valve, for example with a preloaded spring by the device for generating a counter pressure, the spring load being dynamically adjustable by the device for generating a counter pressure (44, 45, 46), and the target pressure or opening pressure of the pressure relief valve being dynamically adjustable.

[0034] This allows the opening pressure to be set to a target pressure, allowing a particularly simple closed-loop control.

[0035] According to another embodiment, the device for generating a counter pressure generates a counter pressure on the compensation piston so that a sufficient excess fill material volume can be expelled so that the target pressure is created.

[0036] The first pressure sensor is preferably in communication with the delivery chamber of the pump.

[0037] The pump is preferably a pump from the following group: rotary vane pumps, auger pumps, etc. These pumps are particularly suitable for filling machines. In principle, however, the invention is also suitable for gear pumps, piston pumps, claw pumps, etc.

[0038] If the pump is a rotary vane pump or an auger pump, it is advantageous to ensure that the pressure sensor has a diameter smaller than the width of the conveying element, for example the vanes of the rotary vane pump or the auger flight. The width of the vanes of a rotary vane pump is understood to mean the outer dimension of the vane that abuts the inner contour of the pump. The width of the auger flight is likewise understood to mean the width of the auger flight on the side where the flight abuts the housing. The sensor can also communicate with the conveying chamber by an opening, for example a gap, in which case the opening or gap has a width smaller than the width of the conveying element. It is thus ensured that the pressure is measured in one chamber and not in a chamber that extends one behind the other.

[0039] The invention also relates to a method for filling a filling material using a filling machine, in particular a filling machine according to any one of claims 1 to 11, in which the filling material is introduced into an inlet region of the pump, compressed in a compression zone and discharged into an outlet region, the pressure in the compression zone being adapted during the filling process by measuring the pressure in the compression zone using a first sensor during the filling process and continuously adjusting the pressure in the compression zone using a regulating device. As explained at the beginning, this gives rise to the possibility of selectively adjusting the pressure in the compression zone and adapting it to different process conditions. The pressure in the compression zone can in particular be adapted continuously.

[0040] In particular, the pressure in the compression zone is controlled in a closed loop manner. Closed loop control by the controller, i.e. mechanical control, was not possible in the prior art.

[0041] Advantageously, according to the method of the present invention, the pressure in the outlet region of the pump is measured by a second pressure sensor and the pressure in the compression region is controlled in a closed loop manner, where the pressure in the compression region is the controlled variable and the pressure in the outlet region is the reference variable.

[0042] According to a preferred embodiment, the actual value is the pressure measured by a first sensor, the target value is the pressure measured in the outlet area by a second pressure sensor and the regulating device is a corresponding actuator, which preferably controls in a closed-loop manner the pressure in the compression area so that it corresponds to the pressure in the outlet area.

[0043] The pressure in the compression zone and the pressure in the outlet zone are preferably equal at the moment the chamber is opened. However, it may happen that only an approximation is possible, for example with deviations up to + / - 10%, for example, due to leakage. Control in a closed loop manner can also be performed with the respective deviations, i.e. the setpoint is higher by a certain amount, for example 0.1% to 20%, than the pressure measured by the second pressure sensor. This amount can be set, for example, in the control device.

[0044] Therefore, the approximation may be subject to deviations, i.e. the more fluidly thin the product is, the more likely leakage may occur and therefore the higher the target pressure should be selected.

[0045] According to a preferred embodiment, the first filling material in the method according to the invention, in particular a foodstuff with a first compressibility, can be filled into the filling machine with a first pressure in the outlet area and a first pressure in the compression area appropriately adapted by the regulating device, and then the second filling material, in particular a foodstuff with a second compressibility, is filled, and the pressure in the compression area is adapted to the second pressure measured in the outlet area by the regulating device. This ensures a suitable pressure ratio during filling. The first filling material and the second filling material can be the same filling material, but with a variable or different composition, such as a different air content or different chunkiness. The first filling material and the second filling material can be different filling materials, such as white sausage meat in the first place and salami chunks in the second place. The invention will now be described in more detail with reference to the drawings. [Brief description of the drawings]

[0046] [Figure 1] FIG. 1 shows a schematic side view of a filling machine according to one embodiment of the present invention. [Diagram 2] FIG. 2 shows diagrammatically a cross section of a rotary vane cell pump according to the invention. [Diagram 3] FIG. 3 shows a schematic longitudinal section of the pump shown in FIG. [Figure 4] FIG. 4 shows a vertical cross-sectional view of another embodiment using an auger pump according to the present invention. [Diagram 5] FIG. 5 illustrates a closed loop control circuit according to one embodiment of the present invention. [Figure 6] FIG. 6 shows a schematic diagram of another embodiment using a compensation cylinder as the adjustment device.

[0047] Detailed Description of the Invention

[0048] Fig. 1 shows a schematic representation of a filling machine 100 according to an embodiment of the present invention. Such a filling machine 100 comprises a funnel 101 which can be filled with, for example, a filling material, in particular a food product such as sausage meat, a paste-like substance, etc. This funnel is in communication with a pump 1, currently for example a rotary vane pump 1 as shown in Figs. 2 and 3, or an auger pump as shown in Fig. 4, which conveys the filling material, for example, to a stuffing tube 102 or a link nozzle, as is generally known, for producing, for example, sausages. Fig. 1 further shows a sausage meat trolley and a lifting device by which the filling material can be filled into the funnel 101. The present invention further comprises a control device 104, i.e. a machine control device.

[0049] Figure 2 shows a cross section of a possible embodiment of the pump 1, which is currently a rotary vane pump. As is particularly clear from Figure 2, the rotary vane pump 1 comprises a pump housing 6, a rotor 2 arranged eccentrically therein and rotatable, and vanes 3 mounted radially displaceable in the latter, the pump housing base and cover together with the pump wall 4 of the pump housing 1, as well as the outer surface 7 of the rotor 2, form a conveying cell 8 and interact in a sealing manner, the pump housing 6 comprises an inlet region 9 and an outlet region 17. Between the inlet region 9 and the outlet region 17, a compression region 11 is arranged. In the inlet region 9, the conveying chamber 8 is completely filled with the filling material. The volume of the conveying chamber 8 is reduced in the compression region 11 of the pump. This causes an increase in the internal pressure of the conveying chamber 8. This increase depends on the compressibility of the filling material. In addition to the first sector in the direction of rotation of the pump in the angular range α, in which the volume of the conveying chamber decreases, the compression region 11 can, as is particularly evident from FIG. 2, comprise a downstream sector in a subsequent angular range β, in which the volume of the conveying chamber 8 and therefore the pressure also remain substantially the same.

[0050] In the compression area 11, for example, as is clear from FIG. 3, a regulating device 40 is provided in the cover of the pump housing 6. The regulating device 40 is currently configured in the form of a pressure relief valve with a compensating piston 14 with a spring 47 and a compensating cylinder 13. The device 45, 44, 46 for generating a counter pressure preloads the spring 47, which means that the installation space 48 of the spring 47 is shorter than for a non-preloaded spring, and a defined opening pressure (for example 1.5-20 bar) is set. The actuators 45, 46 can be used to adjust the length of the installation space 48, whereby the preload force, which depends on the spring properties of the spring used, can also be adjusted. If the pressure in the compression area increases, the force on the contact surface 16 of the compensating cylinder 14 also increases. If the preload force exceeds the force acting by the internal pressure of the conveying chamber 8, i.e. if the pressure in the conveying chamber 8 increases to a pressure greater than the opening pressure, the compensating piston 14 rises and the excess volume of filling material is discharged, in particular via the discharge line 33, as shown in Fig. 3, and is pumped again, for example to the inlet area 9. This allows the pressure in the conveying chamber 8 to be adjusted to the opening pressure of the pressure relief valve 20. The adjustment of the preload force is thus achieved by a device for generating a counterforce, consisting of a plate 46 of the spindle 45 and a drive 44.

[0051] According to the invention, the regulating device 40, in this case for example the motor 44, is connected to a control device 104. According to the invention, the opening pressure of the compensation piston 14 is made dynamically variable. It can therefore be influenced in a selective manner. The regulating device can also be controlled pneumatically or hydraulically.

[0052] Thus, the regulator now acts as a pressure limiter.

[0053] According to the invention, the pump 1 comprises a first pressure sensor 41, which is arranged in the pump wall 4 and can measure the pressure in the compression area 11. The pressure sensor 41 can therefore be integrated flush with the pump wall 4 of the pump housing 6, in particular with the base or cover of the pump housing 6, or can communicate with the conveying chamber 8 of the compression area via an opening. The pressure sensor 41 can also be integrated in the regulating device, i.e. currently the device for generating a counter pressure on the spring 47 or the compensation piston 14, in particular in the corresponding drive (e.g. linear drive or spindle drive - not shown). This saves components. It is only necessary that the pressure in the compression area 11 is determined. The first pressure sensor 41 is connected to a control direction 104. Depending on the purpose, the pressure in the compression area can be kept at a constant level or can be varied. In the case of varying the pressure in the conveying chamber 8, the opening pressure of the pressure relief valve 40 can be varied, for example by varying the preload of the spring 47 via the devices 44, 45, 46. The opening pressure is then set to the target pressure of the conveying chamber 8. The pressure in the compression area, i.e. in the corresponding conveying chamber 8, can thus be limited in a simple manner and, in particular, controlled in a closed-loop manner. For this purpose, active drives, in particular the aforementioned linear drives, can be provided to adjust the preload of the spring. The goal is to set a specific pressure to achieve a maximum pressure for a specific filling material, to set different pressures depending on the air content and type of product, or to set the pressure of the compression area to the pressure of the outlet area 17. For this purpose, a second pressure sensor 50 can be provided, which measures the pressure of the outlet area 17. This sensor 50 is likewise connected to the control device 104. The sensor 50 is preferably arranged in the discharge nozzle, in the side wall or in the base of the outlet area.

[0054] As will be explained in more detail below, the pressure in the compression region may be controlled in a closed loop manner as a function of the pressure measured at the exit region 17 .

[0055] 3 is just one embodiment of the regulator 40. Alternatively, the spring 47 may be omitted and the movement of the compensation piston 14 may be pressure controlled or progress controlled.

[0056] A further embodiment of the regulating device is shown in Fig. 6, which substantially corresponds to the embodiment shown in Fig. 3, except that in this embodiment the regulating device does not comprise a spring-loaded pressure relief valve. The regulating device comprises a compensation cylinder 13, to which the excess volume from the compression zone can be sent in order to set or control a certain pressure in a closed-loop manner. In the compensation cylinder 13, for example, a pressure-controlled or progress-controlled compensation piston 14 is arranged, on which, for example, a device for generating a counterpressure exerts a force, which positions the compensation piston in the compensation cylinder so that the excess volume of filling material can be discharged, for example, via a discharge line 33. For this purpose, a corresponding drive, for example a linear drive, i.e. a motor 44, is provided.

[0057] Instead of adjusting the preload distance in the installation space 48, an adjustable space under pressure can be constructed to allow the counter pressure on the compensation piston to be controlled.

[0058] The present invention has been described in relation to rotary vane pumps, the concepts of the present invention work equally well for auger pumps and twin auger pumps, for example as shown in FIG.

[0059] The auger pump likewise comprises an inlet region 9, a compression region 11, where the filling material is compressed by the auger flights or conveying elements 3, and an outlet region 17, where the filling material is discharged. Here too, a first pressure sensor 41 is arranged in the compression region 11 and a second sensor 50 in the outlet region 17. A regulating device 40 is arranged in the compression region, as in the previous embodiment. The functions, sensors and regulating devices correspond to the elements described in detail in the previous embodiment. Thus, here too, the pressure in the compression region can be regulated, in particular controlled, in a closed-loop manner, in particular as a function of the pressure measured in the outlet region.

[0060] As in the previous embodiment, the pressure sensor 41 advantageously has a diameter a smaller than the width b of the conveying element 3, in particular the width b of the vanes 3 of a rotary vane pump or auger flight. Alternatively, as already mentioned above, the pressure sensor communicates with the conveying chamber 8 in the compression region 11 via an opening, for example a gap narrower than the width of the conveying element 3.

[0061] The method according to the invention and the control device according to the invention will be explained in more detail below with reference to figures 1 to 5. Figure 5 shows a closed loop of a possible embodiment of the invention.

[0062] First, as shown in Fig. 1, the filling material is filled into the filling funnel 101 and passed through the inlet area 9 of the pump 1. For this purpose, the pump operates at a rotational speed such that the conveying chamber 8 is completely filled, or delivers a volume per unit time. The filling material enters the conveying chamber 8 between the two conveying elements 3 (see Fig. 2 and Fig. 4), where it is compressed in a compression area and released in the outlet area 17. The first pressure sensor 41 measures the pressure in the compression area 11 and therefore represents at the moment the measuring device referred to in Fig. 5.

[0063] The control variable x is the pressure in the compression zone. The sensor 50 measures the pressure in the discharge zone 17. The pressure in the discharge zone 17 represents the reference variable w. The pressure measured by the pressure sensor 50 is also sent to the control device. Then e=wx is established as the actuation value. The regulating device, i.e. the actuator, is controlled, for example, by the motor 44 of the regulating device 40, as a function of the actuation value in order to set the corresponding input variable, for example the preload or the opening pressure of the compensation piston 14, respectively. The actuation variable here is, for example, the mechanical length of the installation space 48 for the spring or the resulting spring load. In a closed-loop control system, various disturbance variables z are present, such as pressure fluctuations, jamming, friction, temperature, etc. The sensor 41 measures the resulting pressure in the compression zone and passes this measurement value to the control device. If, for example, the filling material changes, i.e. the proportion of air increases and therefore also the compressibility, a respective control adjustment must be made. This is done continuously during the process.

[0064] When the actual pressure in the compression zone exceeds the target value, ie, the opening pressure of the pressure relief valve, the pressure relief valve opens and the excess fill material is exhausted.

[0065] The pressure in the compression region can also be limited to a specific value by means of a regulating device, independently of the pressure measured in the outlet region, and can in particular be controlled in a closed-loop manner.

Claims

1. A filling machine (100) for filling a filling material, in particular a food product, comprising a pump (1) with an inlet area (9), a compression area (11) and an outlet area (17), A filling machine (100) characterized by a first pressure sensor (41) for measuring the pressure in said compression zone (11) and a regulating device (40) for regulating different pressures in said compression zone.

2. The filling machine (100) according to claim 1, characterized in that the filling machine comprises a control device (104), the regulating device (40) is controllable by the control device (104) and is configured so that the pressure in the compression zone can be dynamically set, in particular controlled in a closed-loop manner.

3. The filling machine comprises: a second pressure sensor (50) for measuring the pressure in said outlet region (17) and a control device (104) configured in particular to control the pressure in said compression region (11) in a closed-loop manner as a function of the pressure measured in said outlet region (17), 3. Filling machine (100) according to claim 1 or 2, characterized in that the pressure in the compression area is preferably a controlled variable and the pressure in the outlet area (17) is a reference variable.

4. 4. The filling machine according to claim 3, characterized in that the control device (104) is configured to control the pressure in the compression area (11) as a controlled variable (X), with the pressure measured by the first pressure sensor (41) as an actual value, with the pressure in the outlet area (17) measured by the second pressure sensor (50) as a setpoint value, and with the regulating device (40) as an actuator.

5. The filling machine (100) according to any one of claims 1 to 4, characterized in that the regulating device (40) is configured as a pressure limiter and is capable of discharging excess volume from the compression area (11), in particular from the conveying chamber, in particular via a discharge line or into a compensation cylinder (13), if a target pressure in the compression area (11) is exceeded.

6. The filling machine (100) according to claim 5, characterized in that the target pressure in the compression area (11) is variably and dynamically adaptable, in particular corresponds to the opening pressure of the regulating device (40), in particular the opening pressure of the regulating device (40) is variably and dynamically adjustable.

7. 7. The filling machine according to claim 1, characterized in that the regulating device (40) is in fluid communication with the compression area (11) and is specifically configured as a valve (40), preferably as a pressure relief valve or a control valve, or comprises a compensating cylinder with a compensating piston.

8. 8. The filling machine according to claim 7, characterized in that the regulating device (40) is configured as a pressure relief valve and comprises, for example, a spring (47) which is preloaded by a device for generating a counterpressure (44, 45, 46), the spring load of which can be dynamically adjusted by the device for generating a counterpressure (44, 45, 46), whereby a target pressure, in particular an opening pressure of the pressure relief valve (40), is dynamically adjustable and / or the regulating device comprises a compensating cylinder (13) which comprises a compensating piston (14) and a volume which can be discharged from the compression area into the compensating cylinder (13), whereby the target pressure is adjustable by a device for generating a counterpressure (44, 25, 46) on the compensating piston, preferably the device for generating a counterpressure comprises a drive, preferably a linear drive or a spindle drive with an integrated pressure sensor.

9. The filling machine according to any one of claims 1 to 8, characterized in that the first pressure sensor (41) is in communication with the conveying chamber (8) of the pump (1) in the compression area (11).

10. A filling machine according to any one of the preceding claims, characterised in that the pump (1) is preferably a rotary vane pump or an auger pump or a twin auger pump.

11. 11. The filling machine according to claim 1, characterized in that the pump is a rotary vane pump or an auger pump and the pressure sensor has a diameter (d) smaller than the width (b) of a conveying element (3), in particular a vane (3) of the rotary vane pump or an auger flight of the auger pump.

12. A method for filling a filling material using a filling machine (100), in particular a filling machine according to any one of claims 1 to 11, comprising the steps of:

13. A method according to claim 12, wherein the filling material is introduced into an inlet region (9) of the pump, compressed in a compression region (11) and discharged into an outlet region (17), the pressure in the compression region (11) being adapted during the filling process by measuring the pressure in the compression region (11) with a first pressure sensor (41) and regulating the pressure in the compression region using a regulating device (40).

13. 13. The method according to claim 12, characterized in that the pressure in the compression zone is controlled in a closed loop manner, in particular the regulating device (40) being controlled by a control device (104) to dynamically regulate the pressure in the compression zone.

14. 14. The method according to claim 13, characterized in that the pressure in the outlet region of the pump (1) is measured by a second pressure sensor (50), the pressure in the compression region (11) is a controlled variable and the pressure in the discharge region is a reference variable, in particular the actual value being the pressure measured by the first sensor (41) and the setpoint being the pressure measured in the outlet region (17) by the second pressure sensor (50) and the regulating device (40) as an actuator controls the pressure in the compression region in a closed-loop manner, preferably corresponding to the pressure in the outlet region, or the actual value being the pressure measured by the first sensor (41) and the setpoint being the pressure measured in the outlet region (17) by the second pressure sensor (50) and the regulating device (40) as an actuator controls the pressure in the compression region in a closed-loop manner.

15. 18. The method according to claim 12, characterized in that a first filling material, in particular a first foodstuff having a first compressibility, is filled into the filling machine (100) at a first pressure in the outlet area (17) and correspondingly adapted by the regulating device (40) and the compression area (11), and then a second filling material, in particular a second foodstuff having a second compressibility, is filled and the pressure in the compression area (11) is adapted by the regulating device to a second pressure measured in the outlet area (17).

16. 16. The method according to any one of claims 12 to 15, characterized in that the pressure in the compression region (11) is set to be equal to or greater than the pressure in the outlet region (17), in particular 0.1-20%, and is controlled in particular in a closed loop manner.

17. 12. The filling machine according to claim 1, characterized in that the pressure sensor (41) is integrated flush with the pump wall (4) of the pump housing (6), or in particular with the base or cover of the pump housing (6), or is communicable with the conveying chamber (8) of the compression area via an opening, or is integrated flush with the regulating device (40), in particular with a spring (47) or with a corresponding drive device (33) of a device for generating a counter pressure on a compensating piston.

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