WEIGHING AND CONVEYING DEVICE AND METHOD FOR CONVEYING AND MASS THROUGHOUT OF BULK MATERIAL

Description

[0001] The invention relates to a weighing and conveying device and a method for conveying and measuring the mass flow rate of bulk material

[0002] Such weighing and conveying systems are used primarily to suck in free-flowing bulk material, such as plastic granules or plastic pellets, determine the mass flow rate, and continuously discharge the bulk material to a downstream conveyor section of a production machine. The conveyor section of the production machine continuously conveys the thus picked-up bulk material, for example, to the extruder, which subsequently extrudes the plastic product.

[0003] On the one hand, a continuous discharge of the bulk material to the conveying area must be ensured so that the production process is not interrupted. Furthermore, the mass throughput, expressed as mass per unit time, must be determined with sufficient accuracy to precisely adjust the production parameters.

[0004] For this purpose, conventional weighing and conveying devices comprise an upper suction conveyor system with a material separator in which a vacuum is created via a vacuum connection, so that an air stream with bulk material is fed to the material separator via a material intake connection. The bulk material can settle in the material separator and is fed downwards into a storage container. A fill level sensor is provided in the material separator which measures the fill level so that when a fill level limit is reached, the vacuum conveying is terminated. This causes the negative pressure in the material separator to collapse, so that an outlet flap held closed by the negative pressure opens due to the weight of the bulk material lying on it. The bulk material is then discharged into the storage container and from there via, for example, a spiral hose downwards to a weighing device with a weighing container.In the weighing device, the weight of the weighing container with the bulk material is continuously measured and thus the mass flow rate is determined as mass per time.

[0005] This results in a correspondingly high structure due to the suction conveyor system, the downstream storage container, and the weighing device with the weighing container. However, in some production plants, the available installation space is limited, making the positioning of the weighing and conveying device problematic. Therefore, continuous gravimetry may not be used in confined spaces. Positioning the weighing and conveying device at a greater distance from the production machine, however, is generally considered problematic, as the creation of longer conveying areas from the production machine reduces measurement accuracy and can lead to segregation of the material mix.

[0006] US 5,450,984 A shows a material feeding device that combines loading, feeding, and refilling in a single, vertically arranged housing with a feed hopper section of the housing below a refill hopper section, the hopper sections being separated by a partition. The material is transported from the refill hopper section to the feed hopper section by a valve, with the material being sucked into the refill hopper section by a vacuum gradient and discharged into the refill hopper section and the feed hopper section depending on a material level. Furthermore, a flap valve is provided for determining the passage of the material from the refill hopper section to the feed hopper section, whereby several such systems can be operated with a single vacuum source.

[0007] DE 3413757A1 describes a method and device for feeding a container with powdery goods. A number of conveyor pipes lead into a weighing container, through which powdery goods are sucked one after the other from storage silos into the weighing container, where they are additively weighed and, after opening a bottom closure, fed to a mixing device. A suction device creates a vacuum in the container, which is released by a vent valve.

[0008] The invention is based on the object of creating a weighing and conveying device and a method for conveying and mass throughput measurement, which enable suction conveying and precise weighing of the bulk material.

[0009] This object is achieved by a weighing and conveying device and a method according to the independent claims. The subclaims describe preferred developments. The method according to the invention can be carried out in particular with a weighing and conveying device according to the invention.

[0010] According to the invention, a weighing hopper enclosing a weighing hopper volume can be closed at its upper inlet and lower outlet. The vacuum connection and the material intake connection are connected to the upper end of the thus sealable weighing hopper. During filling cycles, when the weighing hopper volume is closed, the air flow containing the bulk material is fed directly into the weighing hopper volume. Thus, the weighing hopper itself is also used as a receiving container or collecting container (or "separator") for receiving the conveyed air flow containing the bulk material.

[0011] To initiate a filling cycle, the weigh hopper is closed at its upper inlet and lower outlet. During the filling cycle, the weigh hopper is filled with bulk material until a suitable fill level is reached. The filling cycle is then terminated, and the weighing cycle is initiated. To initiate the weighing cycle, the lower outlet and upper inlet are opened, allowing the weigh hopper to continuously discharge the collected bulk material downwards. In a generally conventional manner, the bulk material is discharged via the impact device, usually an impact cone, to a collecting hopper and from there to the conveying area, e.g., directly to an extruder screw or an upstream conveyor screw.

[0012] The invention thus achieves several advantages: The weighing and conveying system is compact, particularly in the vertical direction, significantly smaller than conventional systems in which a storage hopper and suction conveying system are mounted above the weighing system. The suction conveying system, which is traditionally located in the upper area and includes a receiving hopper or material separation hopper, is functionally combined or integrated with the downstream storage hopper and weighing hopper. This allows for use even in confined spaces, e.g., close to the extruder, allowing a short feed to the extruder, thus ensuring accurate mass throughput determination.

[0013] Furthermore, faster material changes are possible, as only the weighing hopper with the subsequent collecting hopper is filled. While conventionally, the filled material separation hopper, storage hopper, and weighing hopper must be emptied first, with the invention, the weighing hopper with the collecting hopper can be emptied directly and, for example, a different material can be added. This also enables, for example, a quick color change, i.e., a change in the supplied dye. Corrections, for example, in the coloring, can thus be carried out more quickly. This enables high flexibility both in positioning and in material throughput.

[0014] Furthermore, the equipment required is lower due to the elimination of additional stages.

[0015] An adjusting device is provided for closing the upper inlet and the lower outlet of the weighing container. The adjusting device can, in principle, also be designed in several parts, with one adjusting device closing the upper inlet and another adjusting device closing the lower outlet. The adjusting device initially effects a relative adjustment, whereby, in particular, a closure means can be adjusted upwards and / or downwards, and / or the weighing container can be adjusted upwards and / or downwards relative to the closure means. Thus, for example, the weighing container can also be adjusted downwards to adjust the lower outlet.

[0016] According to a preferred embodiment, a closure means is adjusted from below towards the lower outlet, and the weighing container with the closure means is then adjusted upwards.

[0017] According to an advantageous development, the impact device, e.g., a cone, is adjusted vertically directly against the lower outlet of the weighing container, eliminating the need for additional closure devices. Thus, the adjustment device, which is already used to adjust the outlet gap between the lower outlet and the impact device and thus, for example, for adjustment for different material shapes and sizes, e.g., granules, flakes, etc., can also be used for this adjustment.

[0018] According to an advantageous embodiment, the weighing container is adjusted directly vertically upwards against a seal, in particular a seal on an upper support device, whereby its upper inlet is sealed.

[0019] According to a particularly preferred embodiment, a joint adjustment of both the impact means towards the lower outlet and the weighing container upwards against the upper support on the support device is carried out by the adjustment device of the impact means. In particular, a continuous adjustment movement of the adjustment device can take place, which first adjusts the impact means towards the lower outlet and subsequently presses the impact means with material container upwards against the support device. Thus, only the common adjustment device, e.g., a pneumatic adjustment cylinder, needs to be controlled to adjust to the filling position. This enables quick and reliable adjustment with little additional effort, in particular due to the adjustment device already used to adjust the run-up gap.

[0020] The adjusting device preferably actuates a pull rod which is guided from above through the support device, vertically through the weighing container to the impact means and thus first presses the impact means against the lower outlet and subsequently takes the weighing container with it.

[0021] The measurement signals recorded include, on the one hand, a measuring force from load cells, the temporal change of which can be evaluated - in a conventional manner - as material throughput during the weighing cycle. For this purpose, the measuring cells mounted on the support device can directly weigh the material container. Furthermore, the measurement signal from a fill level sensor is recorded, which is designed in particular on the underside of the support device and thus detects the fill level in the weighing container from above. This means that both measuring devices, the load cells and the fill level sensor, can be mounted directly on the support device, e.g. a support plate, whereby the actuating device can also be attached to the support device. This enables simple and joint assembly and contacting of both the actuating device and the measuring devices, in particular without the spatial separation required in conventional systems.During the weighing cycle, the carrier device is largely spatially decoupled from the weighing container so that the measuring signals are not disturbed.

[0022] The level sensor can be designed in different ways: As a distance meter, it can measure the distance of the bulk material from the sensor, e.g., as an optical distance meter, e.g., also laser, or based on radar, in particular radar distance meters, e.g., as a direct or indirect time-of-flight measurement, and / or as an ultrasonic distance meter.

[0023] Particularly preferred embodiments of the fill level sensor are capacitive and / or inductive, in particular by determining changes in capacitance as a function of the fill level, or inductive by measuring an inductance that changes as a function of the fill level. A capacitive or inductive fill level sensor can be used to detect the bulk material below, particularly from above, even when swirled in the air stream. These sensors can also be designed cost-effectively and are less easily contaminated by the fill material. According to the invention, such capacitive or inductive sensors can preferably be attached to the upper support plate and directed downwards, which is not possible with the prior art systems mentioned above with sensors provided on the side.

[0024] The control and recording of the measuring signals as well as the initiation of the cycles is carried out by a control device which records the measured value of the filling level in the filling cycle and, when a limit value of the filling level is reached, ends the filling cycle by closing a vacuum valve and controlling the actuating device to open the weighing container at the top and bottom, thereby initiating the weighing cycle.

[0025] During the weighing cycle, the measuring force signal is recorded and evaluated. When the measuring force signal reaches a lower minimum value, emptying of the weighing container is detected and the weighing cycle is terminated by closing the weighing container. The next filling cycle begins when the vacuum valve is subsequently opened.

[0026] According to an advantageous embodiment, the weighing and conveying device is designed such that in the filling position, the weighing container volume formed in the weighing container is connected to external spaces only through the vacuum connection and the material suction connection.

[0027] According to an advantageous embodiment, the weighing and conveying device is designed such that the weighing container can be vertically adjusted without tension in upper guides, in particular in guides in the area of ​​receiving pieces of load cells.

[0028] According to an advantageous embodiment, the weighing and conveying device is designed such that one or more load cells are provided on the support device and receive the weighing container via receiving pieces.

[0029] According to an advantageous embodiment, the weighing and conveying device is designed such that the weighing container tapers at least in some regions from its upper inlet to its lower outlet.

[0030] According to an advantageous embodiment, the weighing and conveying device is designed such that the weighing container tapers conically downwards in a central region and is cylindrical below the conical region, wherein it is guided in the collecting funnel in its lower cylindrical region.

[0031] The invention is explained below with reference to an embodiment of the invention and the accompanying drawings. They show: Fig. 1 shows a weighing and conveying device according to an embodiment of the invention in a weighing cycle; Fig. 2 shows the weighing and conveying device from Figure 1 in section AA; Fig. 3 the weighing and conveying device from Figure 1, 2in a filling cycle; Fig. 4 the weighing and conveying device Figure 3 in section BB; Fig. 5 a time diagram of the successive cycles, Fig. 6 a weighing and conveying device according to the prior art.

[0032] Figure 6 shows a weighing and conveying device 101 according to the prior art, which is intended for detecting a mass flow rate of a free-flowing bulk material 130. The weighing and conveying device 101 has a scale 102 at the bottom with a weighing container 103 that tapers conically from its upper inlet 106 to its lower outlet 104.

[0033] Above the scale 102, a storage container 110 is provided, at the lower end of which a flexible hose, e.g., a spiral hose 112, is led to the inlet 106 of the scale 102. The free-flowing bulk material is fed to an upper inlet 114 of the storage container 110 by a suction conveyor system 120, which in turn has a collecting container 134 with a vacuum connection 121 for connection to a vacuum generator, a material suction connection 122, and a fill level sensor 124.

[0034] In the suction conveyor system 120, a vacuum is generated via the vacuum connection 121, through which an air stream containing the bulk material is sucked in from a storage container via the material intake connection 122. The bulk material 130 is collected in the material separator formed above the storage container 110, settles in the collecting container 134, and settles at the lower end of the suction conveyor system 120 in the designated end region 140, from where the bulk material 130 then falls into the storage container 110. During filling cycles, a shut-off element located below the spiral hose 112, i.e., at the inlet of the scale, opens, allowing the bulk material to fall from the storage container and the spiral hose into the weighing container 103. The weighing hopper 103 continuously discharges the bulk material 130 downwards via its lower outlet 104, where the material is mixed or distributed by an impact cone and, for example,then enters a collecting hopper, from where it is then taken away by a screw conveyor or directly by an extruder.

[0035] The weighing and conveying device 101 according to the prior art thus has a correspondingly high structure with a corresponding number of parts.

[0036] The Figures 1 to 4 and the measurement diagram of the Fig. 5show an embodiment of the invention. A weighing and conveying device 1 has a support plate 3 with load cells 4 and a weighing container 5 provided below the support plate 3. The weighing container 5 has an upper inlet 6 and tapers conically downwards in its central region 5b to its lower cylindrical region 5c with its lower outlet 7. In the region of the lower outlet 7, a baffle cone 12 for distributing or mixing the falling bulk material 20 is provided on the weighing container 5; a collecting funnel 10 is provided below the lower outlet 7.

[0037] Provided on the support plate 3 are a vacuum connection 23 for connection to a vacuum line 33 and a material suction connection 24 for connection to a material suction line 34. Furthermore, a pneumatic cylinder 25 is attached to the support plate 3, which vertically adjusts a pull rod 26. The pull rod 26 extends downwards through the weighing container 5 and accommodates the vertically adjustable impact cone 12, which can be adjusted upwards towards the lower outlet 7 of the weighing container 5. The weighing container 5 is in turn guided in a vertically adjustable manner, e.g. by being guided by upper tabs provided in the area of ​​the receiving pieces 52. Furthermore, a plain bearing can be provided to guide the impact cone 12 during opening or closing. Figures 3 and 4 show the weighing and conveying device 1 in the filling cycle I of the weighing container 5. The filling cycle I is shown in Fig. 5 at time t2. To initiate the filling cycle I, a Fig. 1 The control device 50 shown actuates the pneumatic cylinder 25 so that it pulls the pull rod 26 with the impact cone 12 provided at the lower end of the pull rod 26 upwards. The impact cone 12 thus moves against the lower outlet 7 of the weighing container 5 and closes it. The weighing container 5 is then pulled upwards and pressed with its upper edge or upper inlet 6 against a seal 8 on the underside of the support plate 3. The weighing container volume 9 of the weighing container 5 is thus closed by the support plate 3 and the impact cone 12 and is only connected to the outside space via the vacuum connection 23 and the material intake connection 24.

[0038] Subsequently, the control device 50 controls a vacuum valve 32 provided in the vacuum line 33 and delivers a vacuum required for the suction conveyance to the vacuum connection 23 and thus into the weighing container volume 9, so that a bulk material air stream is sucked in from a material supply via the material suction connection 24 and the material suction line 34 and reaches the weighing container volume 9, where the bulk material 20 is deposited.

[0039] In the filling cycle I, the fill level of the bulk material 20 in the weighing container 5 is detected by a fill level sensor 35 provided on the carrier plate 3. The fill level sensor 35 can detect the fill level, ie the upper edge of the picked up bulk material 20, using different measuring principles, e.g. optical, radar level sensors, ultrasound, and in particular capacitive or inductive. The control device 50 receives the measurement signal M of the fill level sensor 35 and compares the thus determined fill level with a maximum fill level M-max. At time t3 of the Fig. 5the filling level F reaches the maximum filling level M-max, whereupon the control device 50 terminates the filling cycle I and initiates the weighing cycle II by first closing the vacuum valve 32 and thereby terminating the vacuum conveying. Subsequently, the control device 50 controls the pneumatic cylinder 25 in such a way that the drawbar 26 with the impact cone 12 and the weighing container 5 is moved downwards back into its Figure 1, 2 To ensure that the impact cone 12 and the weighing container 5 reach their correct end position without stress, they are advantageously guided vertically with pins and elongated holes. Thus, weighing cycle II is set at time t1.

[0040] The weighing container 5 hangs in receiving pieces 52 of the load cells 4, which measure the weight of the weighing container 5 with the bulk material 20 during the weighing cycle II and output a measuring force signal F to the control device 50. A defined, circumferential outlet gap 54 is formed between the lower outlet 7 of the weighing container 5 and the impact cone 12. The height of the outlet gap 54 or the outlet distance d is preferably adjusted before the conveying process depending on the bulk material, e.g., depending on the diameter of the particles of the bulk material, such as flakes, granules, grains, etc.

[0041] In weighing cycle II, the bulk material 20 received in the weighing hopper 5 falls downward through the lower outlet 7 against the impact cone 12, mixing the bulk material 20. The bulk material 20 then enters the collecting hopper 10 and continues downward to a conveying area 60. This conveying area 60 can be formed by an additional conveyor screw or directly by the screw of the extruder, so that the bulk material 20 received here can be continuously processed. The load cells 4 continuously measure the weight and can thus record the weight loss or the material flow as mass per unit time.

[0042] In the Figure 1, 2In the position shown for the weighing cycle II, the pneumatic cylinder 25 is not loaded via the drawbar 26; the weighing container 5 with the impact cone 12 hangs only in the receiving pieces 52 of the load cells 4. Thus, the measurement result is not influenced by the pneumatic cylinder 25 and the drawbar 26. Since the lower outlet 7 of the weighing container 5 is closed during the filling cycle I and no material can escape, a sufficiently dimensioned collecting hopper 10 is provided to bridge the time required for the filling cycle I. This thus buffers enough material or bulk material 20 to Fig. 5 to ensure an uninterrupted supply at times t2 and t3. This ensures a continuous supply of the bulk material 20 to the conveying area 60 and thus an uninterrupted supply to the extruder or processing machine.

[0043] In the diagram of the Figure 5the measuring force F measured by the load cells 4 is shown as a function of time t. When weighing cycle II is initiated at time t0, a maximum measuring force Fmax is measured. Subsequently, the bulk material 20 falls downwards through the outlet gap 54 from the weighing container 5 into the collecting hopper 10, so that the measuring force F drops until time t1. The control device 50 detects that the measuring force F reaches an empty weight F0 or minimum weight, whereby the end of weighing cycle II is determined. Subsequently, the control device 50 initiates the next filling cycle I, in which the measuring force F is not relevant, but rather the fill level is measured, in order to subsequently end the filling cycle. List of reference symbols

[0044] 1 Weighing and conveying device 3 Support plate 4 Load cells 5 Weighing container 5b Middle conical area of ​​the weighing container 5 5c Lower cylindrical area with the lower outlet 7 6 Upper inlet of the weighing container 5 7 Lower outlet of the weighing container 5 8 Seal on the underside of the support plate 3 9 Weighing container volume 10 Collecting funnel 12 Impact cone 14 Suction conveyor system 15 Weighing area 20 Bulk material 23 Vacuum connection 24 Material intake connection 25 Pneumatic cylinder, actuating device 26 Drawbar 30 Slide bearing 32 Vacuum valve 33 Vacuum line 34 Material intake line 35 Fill level sensor 50 Control device 52 Mounting piece of the load cells 4 on the weighing container 5 54 Outlet gap 60 Conveying area, e.g. Conveyor screw or extruder FMeasuring force signal, weighing signal FmaxMaximum weight F0Empty weight MFill level MmaxMaximum fill level DMass flow rate dOutlet distance tTime 101 Weighing and conveying equipment 102 Scale 103 Weighing hopper 104 Scale outlet 102 106 Scale inlet 102 112 Spiral hose 110 Storage hopper 114 Storage hopper inlet 110 140 End section 120 Suction conveyor system 121 Vacuum connection 122 Material suction connection 124 Level sensor 130 Bulk material 134 Receptacle, material separator

Claims

1. Weighing and transporting device (1) for detecting mass flow rates and discharging bulk material (20), comprising: - a weighing container (5) having an upper inlet (6) for receiving the bulk material (20) and a lower outlet (7) for discharging the bulk material (20), - at least one weighing cell (4) for measuring the weight of at least the weighing container (5) with bulk material (20) contained therein and for discharging a measuring force signal (F), - a vacuum conveyor region (14) having a vacuum connection (23) for connecting to a vacuum line (33) and a material suction coupling (24) for connecting a suction intake line for an airstream with bulk material (20) contained therein, - a filling level sensor (35) for measuring a filling level of the bulk material (20) in the weighing container (5) and outputting a filling level signal (M), characterised in that - at least one actuator (25) for closing the upper inlet (6) and the lower outlet (7), - a controller means (50), being designed to receive the measuring force signal (F) and the filling level signal (M) and to control said at least one actuator (25) for adjusting between a filling position (II) with closed upper inlet (6) and closed lower outlet (7) of the weighing container (5) and a weighing position with open upper inlet (6) and open lower outlet (7) of the weighing container (5).

2. Weighing and transporting device (1) according to claim 1, characterised in that an impact means (12) is provided below the lower outlet (7) for distributing or mixing the bulk material (20), in particular, an impact cone (12), the impact means (12) being adjustable by means of the actuator (25) between its lower position in the weighing position for a weighing cycle (I) in which a discharge gap (54) is formed between the lower outlet (7) and the impact means (12), and its upper position in the filling position for a filling cycle (II) in which the impact means (12) closes the lower outlet (7), in particular, in an airtight manner.

3. Weighing and transporting device (1) according to claim 2, characterised in that the weighing container (5) is vertically adjustable between its lower weighing position in which it is spaced apart from a support means (3), and its upper filling position in which its upper inlet (6) and / or its upper edge lies in sealing contact with the support means (3), the common actuator (25) being designed and controllable to adjust - the impact means (12) against the lower outlet (7) in a first partial motion and - subsequently the impact means (12) with the weighing container (5) upwards against the support means (3) in a subsequent second partial motion of the actuator (25, 26), where in the filling position the impact means (12) closes the lower outlet (7) and the support means (3) closes the upper inlet (6) of the weighing container (5) in a sealing manner.

4. Weighing and transporting device (1) according to claim 2 or 3, characterised in that the actuator (25), e.g. a pneumatic actuating cylinder (25), is connected to the impact means (12) via a drawbar (26) extending vertically downwards through the weighing container (5), and the impact means (12) is vertically adjustable upwards via the drawbar (26).

5. Weighing and transporting device (1) according to one of the preceding claims, characterised in that it comprises a collecting hopper (10) which is arranged, at least in part, below the lower outlet (7), and which is further designed to receive bulk material (20) falling out of the lower outlet (7) and to forward it to its lower discharging outlet.

6. Weighing and transporting device (1) according to one of the preceding claims, characterised in that the controller means (50) is designed and configured, depending upon at least the measuring signal (M) of the filling level sensor (35) and the measuring force signal (F) - (I) to output control signals for initiating a filling cycle (I) to = said at least one actuator (25) for closing the lower outlet (7) and the upper inlet (6) of the weighing container (5), thereby creating an enclosed weighing container volume (9) to be filled via the material suction coupling (24), = and, subsequently, to a vacuum valve (32) for opening a vacuum line (33) provided at the vacuum connection (23), - (II) and, for initiating a weighing cycle (II), to output control signals (S) to = said vacuum valve (32) for closing the vacuum line (33), = and, subsequently, to said at least one actuator (25, 26) for opening the weighing container (5) at its lower outlet (7) and its upper inlet (6).

7. Weighing and transporting device (1) according to one of the preceding claims, characterised in that the controller means (50) is further designed and adapted to adjust the discharge gap (54) for controlling the mass throughput, depending upon a mass throughput determined from the measuring force signal (F) and by controlling the actuator (25).

8. Weighing and transporting device (1) according to one of the preceding claims, characterised in that the material suction coupling (24) extends through the support means (3) and, at least in part, into the weighing container (5), for direct filling of the weighing container (5) without an upstream storage container.

9. Weighing and transporting device (1) according to one of the preceding claims, characterised in that the support means comprises a support plate (3) at which one or more of the following elements are provided: the filling level sensor (35), at least one weighing cell (4), the vacuum connection (23), the material suction coupling (24), the actuator (25), a gasket (8) for sealing the upper inlet (6) of the weighing container (5).

10. Weighing and transporting device (1) according to one of the preceding claims, characterised in that the filling level sensor (35) is designed in accordance with one or more of the following embodiments: - capacitive, in particular, by determining changes in a capacitance depending on the filling level, - inductive, in particular, by measuring an inductance that changes depending on the filling level, - as an optical distance meter, e.g., including laser, - as a radar, in particular, radar distance meter, e.g., as direct or indirect time-of-flight measurement, - as an ultrasound distance meter.

11. System, made up of a weighing and transporting device (1) according to one of the preceding claims, a vacuum line (33) comprising a vacuum valve (32), a material feeder line (24), being guided in a material container containing the bulk material (20), a transport region (60) below the weighing and transporting device (1), and a production machine.

12. Method for transporting and detecting mass flow rates of bulk material (20), wherein in alternating filling cycles (I) and weighing cycles (II) bulk material (20) is received in a weighing and transporting device (1) with a weighing container (5), detected, and put out to a transport region (60) of a production machine, - wherein in the filling cycle (I) - a vacuum is created in a weighing container volume (9) of the weighing container (5), - an air stream with bulk material (20) is sucked via a material suction coupling (24) coupled to the weighing container volume (9) so that the bulk material (20) is deposited in the weighing container volume (9), - a filling level of the bulk materials (20) is measured, and - upon determination of a maximum filling level, the filling cycle (I) is terminated, and - wherein in the weighing cycle (II) - the bulk material (20) moves continuously from the weighing container volume (9) downwards via an impact means (12) to the transport region (60) of the production machine, - wherein, for adjusting to a filling position and for initiating the filling cycle (I), the lower outlet (7) and the upper inlet (6) of the weighing container (5) are closed and subsequently a vacuum is applied to the vacuum connection (23), - wherein, for adjusting to a weighing position and for initiating the weighing cycle (II), the application of vacuum to the vacuum connection (23) is terminated and subsequently the lower outlet (7) and the upper inlet (6) of the weighing container (5) are opened.

13. Method according to claim 12, characterised in that - when adjusting into the filling position - the lower outlet (7) is closed by vertical adjustment of the impact means (12) in an upwards direction against the lower outlet (7), and / or - the upper inlet (6) is closed by vertical adjustment of the weighing container (5) in an upwards direction against a support means (3), - and, correspondingly, when adjusting into the weighing position - the lower outlet (7) is opened by vertical adjustment of the impact means (12) in a downwards direction, thereby setting a discharge gap (54) between the lower outlet (77) and the impact means (12), and / or - the upper inlet (6) is opened by vertical adjustment of the weighing container (5) in a downwards direction.

14. Method according to claim 13, characterised in that the upwards adjustment of the impact means is carried out in a first partial motion of an actuator (25) and, subsequently, the upwards adjustment of the weighing container (5) is carried out in a second partial motion of the same actuator (25), in particular, as a continuous adjusting motion.

15. Method according to one of the claims 12 through 14, characterised in that the material throughput is regulated by adjusting the discharge gap (54) between the lower outlet (7) and the impact means (12).

16. Method according to one of the claims 12 through 15, characterised in that the filling cycle (I) and the weighing cycle (II) are initiated automatically, determining the filling level of the bulk material (20) in the weighing container (5) and measuring the measuring force (F) and controlling the actuator means (25) and a vacuum valve (23)17. Method according to one of the claims 12 through 16, characterised in that the bulk material (20) is moved continuously from the weighing container volume (9) downwards via the impact means (12) into a collecting hopper (10) and from a lower discharging outlet of the collecting hopper (10) to the transport region (60) of the production machine, wherein in the weighing cycle (II) the collecting hopper (10) is filled such that in the next following filling cycle (I) the bulk material (20) is discharged from the collecting hopper (10) to the transport region (60) continuously and without interruption until, in the next following weighing cycle (II), the collecting hopper (10) is again filled with the bulk material (20).

18. Method for extruding an extrusion product, in which bulk material (20), e.g. plastic pellets, plastic granulate or plastic flakes, is continuously measured in its mass flow rate and fed to the transport region (60) using a method according to one of the claims 12 through 17, wherein in the transport region (60) the received bulk material (20) is continuously conveyed towards the production machine, in particular, an extruder, where it is extruded, in particular, with the extrusion being controlled by adjusting a discharge gap (54).