Method for operating a concrete pump system, concrete pump system, computer program product

Abstract

A method for operating a concrete pump system, in which liquid concrete (43) is introduced into a pre-filling container (16) of a concrete pump (15) from a liquid concrete store (41, 66). The liquid concrete (43) is sucked out of the pre-filling container (16) by a pumping device (29) and is delivered along a delivery line (17) such that the liquid concrete (43) emerges at a distal end of the delivery line (17). The concrete pump (15) is equipped with a control unit (44). The control unit (44) is fed a measured value for a state variable of the concrete pump. The measured value is processed in the control unit (44) in order to generate a control signal, on the basis of which the volume flow (58) of the liquid concrete (43) passing from the liquid concrete store (41, 66) into the pre-filling container (16) is set. The invention also relates to a concrete pump system and to a computer program product.

Description

[0001] Method for operating a concrete pumping system, concrete pumping system, computer program product

[0002] The invention relates to a method for operating a concrete pumping system, a concrete pumping system and a computer program product.

[0003] The application area of ​​concrete pumps is increasingly extending to the production of concrete structures using 3D printing, i.e. without the shape of the concrete structure being predetermined by formwork. For this purpose, the liquid concrete is pumped in such a way that it emerges from the outlet end of a delivery line in the form of a strand with a predetermined cross-section. Upon exiting the delivery line, the liquid concrete has a consistency such that the cross-section of the strand is retained when the strand is placed on a surface. Liquid concrete that meets these requirements has lower flowability than conventional liquid concrete.

[0004] If a concrete pump is operated with less flowable liquid concrete, the liquid concrete filled into the pre-filling tank of the concrete pump will penetrate less quickly and less evenly to the bottom of the pre-filling tank than usual. There is a risk that liquid concrete quantities will remain in the pre-filling tank for too long because liquid concrete added later will be the first to leave the pre-filling tank. This particularly applies to liquid concrete quantities that adhere to the wall in an upper section of the pre-filling tank. Liquid concrete which no longer has the right consistency as a result of remaining in the pre-filling tank for too long can lead to a malfunction in the operation of the concrete pump. The object of the invention is to present a method for operating a concrete pump system, a concrete pump system and a computer program product with which these disadvantages are avoided. This object is achieved by the features of the independent claims.Advantageous embodiments are specified in the subclaims.

[0005] In the method according to the invention for operating a concrete pump system, liquid concrete is introduced from a liquid concrete supply into a pre-filling tank of the concrete pump. The liquid concrete is sucked out of the pre-filling tank by a pumping device and conveyed along a delivery line so that the liquid concrete exits at a distal end of the delivery line. The concrete pump is equipped with a control unit. A measured value via a state variable of the concrete pump is fed to the control unit. The measured value is processed in the control unit in order to generate a control signal on the basis of which the volume flow of the liquid concrete flowing from the liquid concrete supply into the pre-filling tank is adjusted.

[0006] Pouring liquid concrete into the pre-filling tank has so far been a non-critical process that does not require a high level of expertise. The instruction to the liquid concrete operator, such as the driver of a truck mixer, can essentially be limited to always adding enough liquid concrete to ensure the pre-filling tank is fully filled. With conventional, free-flowing liquid concrete, a high degree of tolerance can be granted for the implementation of this instruction without impairing the operation of the concrete pump.

[0007] The invention has recognized that with less flowable liquid concrete, as used for example in 3D printing applications, it is helpful to apply greater precision when feeding liquid concrete to the pre-filling tank. The invention proposes processing a measured value via a state variable of the concrete pump in order to adjust the volume flow of liquid concrete entering the pre-filling tank. By processing the measured value for the purpose of generating a control signal and by varying the amount of liquid concrete fed to the pre-filling tank as a function of the control signal, the volume flow can be adjusted at any time to suit the operating state of the concrete pump.

[0008] In a concrete pump system, the concrete pump and the liquid concrete supply are separate units. For example, the concrete pump can be part of a concrete pump vehicle and the liquid concrete supply can be arranged on a separate concrete mixer vehicle. In contrast to integrated devices, such as those known from DE 10 2008 017 123 A1, in which the liquid concrete supply and the concrete pump form a unit within a common vehicle, in a concrete pump system consisting of technically separate units there is generally no direct interface available via which the operation of the liquid concrete supply and the concrete pump can be coordinated. The invention has recognized that a measured value via a state variable of the concrete pump can nevertheless be used expediently to improve the interaction between the components of the system according to the invention.

[0009] The concrete pump system can comprise a first operating state in which the concrete pump delivers liquid concrete along the delivery line and in which liquid concrete flows from the liquid concrete reservoir to the prefill tank of the concrete pump. The concrete pump system can comprise a second operating state in which the concrete pump and the liquid concrete reservoir are spatially separated from one another so that no liquid concrete can flow from the liquid concrete reservoir into the prefill tank. In the second operating state, the concrete pump can be out of operation, so that no liquid concrete is delivered along the delivery line. Alternatively or additionally, it is also possible for the concrete pump to deliver liquid concrete along the delivery line in the second operating state and for liquid concrete to be supplied to the prefill tank from another source. In this way, continuous operation of the concrete pump is possible, even if the liquid concrete reservoir needs to be refilled in the meantime.

[0010] The measured value can represent the fill level of the priming tank. The fill level of the priming tank can be measured directly using a fill level sensor. It is also possible to infer the fill level from other variables. For example, information about the fill level of the priming tank can be derived from a measured weight. Alternatively, the fill level of the priming tank could be inferred from the ratio between the amount fed to the priming tank and the amount pumped by the concrete pump.

[0011] In one embodiment, a signaling device is actuated using the control signal. The signaling device can be switched between different signal states using the control signal. The signaling device can be designed to emit a signal that can be perceived by a person. This can be an optical signal or an acoustic signal, for example. The method can be carried out in such a way that an operator changes the volume flow of liquid concrete that is fed to the pre-filling container based on the signal they perceive. The signaling device can comprise a first signal state according to which the volume flow is kept unchanged. The signaling device can comprise a second signal state according to which the volume flow is reduced. The signaling device can comprise a third signal state according to which the volume flow is increased.Additional signal states are possible, for example, to enable differentiation between a strong and a slight increase or decrease in the volume flow. For example, a fourth signal state can correspond to a strong decrease in the volume flow, and a fifth signal state can correspond to a strong increase in the volume flow.

[0012] Additionally or alternatively, the control signal can be used to control a dosing device for the liquid concrete supply. The dosing device can be designed to adjust the volume flow of the liquid concrete flowing from the liquid concrete supply into the pre-filling tank. The control signal can be sent to the dosing device so that the state of the dosing device is changed by the control signal. The dosing device can form an actuator of a closed control loop, with which the fill level of the pre-filling tank is regulated to a setpoint.

[0013] The dosing device can be an integral part of the system component used to supply the liquid concrete supply. For example, if the liquid concrete is supplied by a truck mixer, the dosing device can be a mixer motor used to discharge the liquid concrete from a storage hopper of the truck mixer.

[0014] In practice, the concrete pump and the system component that provides the liquid concrete supply are often units that are technically and organizationally separate from one another. It is therefore not always easy to create a suitable interface between the concrete pump and the relevant system component. A buffer device can be arranged between a storage tank filled with liquid concrete and the pre-fill tank of the concrete pump. The buffer device can be designed so that it is only coupled to the storage tank when required. The buffer device can then be used selectively with different storage tanks, for example different truck mixers. The buffer device can be designed to provide a liquid concrete supply with which the pre-fill tank is fed.The dosing device can be designed to adjust the volume flow of liquid concrete flowing from the buffer device into the prefill tank. A direct interface between the concrete pump and the storage tank from which the buffer device is fed can then be dispensed with. It is only necessary to position the buffer device appropriately relative to the storage tank so that the liquid concrete can flow from the liquid concrete supply to the buffer device. For this purpose, the buffer device can be mechanically coupled to the storage tank.

[0015] Similar specifications can apply to the volume flow from the storage tank to the buffer device as with conventional concrete pumps, namely that the buffer device must always be well filled with liquid concrete. The personnel responsible for filling the buffer device are therefore not subject to any more stringent requirements than usual. The precise metering of the volume flow supplied to the pre-fill tank can be achieved with the metering device of the buffer device.

[0016] The buffer device can be designed as a chute. The chute can have a support surface that carries the liquid concrete coming from the liquid concrete supply. The support surface can be inclined so that the liquid concrete moves under the influence of gravity from an inlet end to an outlet end of the chute. The outlet end of the chute can be arranged above the pre-filling container so that liquid concrete emerging from the chute falls into the pre-filling container. The dosing device can be arranged at the outlet end of the chute. The chute can be designed, for example, as a gutter or as a pipe.

[0017] The volume flow that flows from the liquid concrete storage container into the buffer device can be adjusted depending on the fill level of the buffer device. The buffer device can be equipped with a fill level sensor. The measured value from the fill level sensor can be processed to generate a second control signal. The volume flow of liquid concrete that flows from the liquid concrete storage container to the buffer device can be varied depending on the second control signal. The second control signal can be used to control a signaling device by which an operator can adjust the volume flow flowing into the buffer device. It is also possible for the liquid concrete-filled storage container to comprise a second dosing device with which the volume flow flowing into the buffer device can be adjusted.The second control signal can be used to activate the second dosing device. No manual intervention is then required to ensure that the buffer device is always well filled with liquid concrete.

[0018] The concrete pump can be designed to produce concrete structures by means of 3D printing. A metering pump can be arranged in the delivery line of the concrete pump. An outlet end of the delivery line can be designed as a pressure head. The pressure head can be designed in such a way that the liquid concrete emerges from the pressure head as a strand with a predetermined cross-section. The metering pump can be set up in such a way that a uniform volume flow of liquid concrete passes through the pressure head. With conventional concrete pumps, a uniform volume flow at the outlet end of the delivery line is not absolutely necessary, which is why intermittent delivery of the

[0019] Liquid concrete can be accommodated along the delivery line. The concrete pump can include a positioning system that allows the pressure head to be moved along predetermined paths.

[0020] A dosing pump arranged in the delivery line is often designed so that only grains of a limited size can pass through. It is therefore advantageous to use liquid concrete with a small grain size. The liquid concrete fed to the priming tank can be sieved to filter out excessively large grains or foreign matter. In one embodiment, the liquid concrete is sieved before entering the priming tank. The priming tank can have an upper edge designed so that a sieve can be placed onto the edge. For a better screening result, the sieve can be vibrated while the liquid concrete passes through the sieve. The concrete pump can include a vibrating drive that drives the movement of the sieve.

[0021] The control unit of the concrete pump can be designed to control the interaction of the components during implementation of the method according to the invention. The control unit can be designed to determine the first control signal, based on which the volume flow of liquid concrete passing from the liquid concrete reservoir into the pre-filling tank is adjusted. For this purpose, the control unit can process measured values ​​representing the fill level of the pre-filling tank.

[0022] Additionally or alternatively, the control unit can process status data from the pumping device. The status data can relate to the volume flow delivered by the pumping device and / or the pressure at which the liquid concrete is pumped into the delivery line. The current operating status of the pumping device is one of the parameters that determines how much liquid concrete should be fed into the pre-filling tank.

[0023] Additionally or alternatively, the control unit can process process flow data from a current or upcoming 3D printing process. During 3D printing of concrete, a print head arranged at a distal end of the delivery line is moved in such a way that the emerging strand of liquid concrete is deposited in predetermined positions so that the desired concrete structure is built up from the concrete layers according to a predetermined plan. The associated flow data contains information about how much liquid concrete will be required in the near future. This information is useful because a certain amount of time passes before the liquid concrete flowing from the liquid concrete supply into the pre-filling container reaches the delivery line. Using the flow data, the first control signal can, for example, be designed so that the pre-filling container is almost empty when the 3D printing process is finished.

[0024] The control unit can additionally or alternatively be designed to generate the second control signal, on the basis of which the volume flow passing from the storage container into the buffer device is adjusted. For the purpose of determining the second control signal, the control unit can process measured values ​​that represent the fill level of the pre-fill container, process measured values ​​that represent the fill level of the buffer device, process status data of the pumping device of the concrete pump and / or process sequence data of a current or upcoming 3D printing process. As explained, each of these pieces of information has an influence on how large the volume flow should be that arrives at the buffer device.The control unit can be designed to process a setpoint value for the fill level of the pre-filling tank in order to generate the control signal based on which the volume flow of the liquid concrete flowing from the liquid concrete supply into the pre-filling tank is adjusted. The control unit can compare an actual fill level value with the setpoint value and derive the control signal based on which the volume flow entering the pre-filling tank is adjusted from the difference between the actual value and the setpoint value.

[0025] The setpoint for the fill level can be a constant setpoint that remains unchanged throughout a 3D printing process. In particular, the setpoint can remain unchanged while a concrete layer of a 3D printing process is being generated. Creating a concrete layer is the process of adding a continuous line of liquid concrete flowing from the delivery line to the concrete structure being produced.

[0026] A key finding of the invention is that it can be advantageous if the setpoint for the fill level of the pre-filling container is varied within a time span within which a single concrete layer of a 3D printing process is produced. It has been found that with an unchanged setpoint for the fill level, there is a risk that parts of the liquid concrete will assume a static state and will not be included in the flow of the volume flow coming from the liquid concrete supply into the pumping device. This can particularly concern those parts of the liquid concrete that are located in an upper section of the pre-filling container and close to the edge of the pre-filling container. If the fill level of the pre-filling container is lowered, a depression forms in the middle of the pre-filling container, into which the

[0027] Liquid concrete slides from the edge. This prevents components of the liquid concrete from remaining in the pre-filling container for too long.

[0028] The method can be carried out in such a way that, during the production of an individual concrete layer in a 3D printing process, a first setpoint value for the fill level and a second setpoint value for the fill level that is different therefrom are specified. The first setpoint value can be higher than the second setpoint value. The first setpoint value can be applied at the start of a printing process. The second setpoint value can be applied for a middle phase of a printing process. After a change from the first setpoint value to the second setpoint value, the volume flow passing from the liquid concrete supply into the pre-filling container can be set in such a way that it is smaller than the volume flow sucked out of the pre-filling container by the pumping device. Relative to the volume of liquid concrete in the pre-filling container, the first setpoint value can be at least 10%, preferably at least 20%, more preferably at least 50% higher than the second setpoint value.

[0029] While the same concrete layer is being produced during the 3D printing process, a third setpoint can be specified which is higher than the second setpoint, whereby the ratio can be the same as specified for the first setpoint. The third setpoint can be applied chronologically after the second setpoint. After a change from the second setpoint to the third setpoint, the volume flow passing from the liquid concrete supply into the pre-filling tank can be adjusted so that it is greater than the volume flow sucked from the pre-filling tank by the pumping device.

[0030] In other words, the method can be carried out such that, during the production of a single concrete layer of a 3D printing process, the fill level of the pre-fill container is initially high according to a first setpoint, then decreases to a lower value according to a second setpoint, and then increases again to a higher value according to a third setpoint. A sequence that includes alternating between a higher fill level and a lower fill level can be repeated once or multiple times during a single printing process.

[0031] At the end of a print run, the fill level of the prefill tank may be low. It is easier to keep the liquid concrete remaining in the prefill tank moving during a print pause when the amount of liquid concrete is small. Information about when a print run will end can be provided to the control unit from the 3D printing process's runtime data.

[0032] The liquid concrete supply can be located in a storage container that is part of a truck mixer. A truck mixer is a truck that carries liquid concrete. The truck mixer can be equipped with a drive element with which the volume flow of liquid concrete emerging from the liquid concrete supply can be adjusted. It is also possible for the liquid concrete supply to be located in a stationary storage container, such as a silo. The liquid concrete flowing from the storage container into the pre-filling container can fall into the pre-filling container under the influence of gravity.

[0033] The invention also relates to a concrete pump system with a concrete pump and a liquid concrete supply. During operation of the concrete pump system, liquid concrete is introduced from the liquid concrete supply into a pre-filling tank of the concrete pump. The concrete pump comprises a pumping device for sucking liquid concrete from the pre-filling tank and conveying it along a conveying line so that the liquid concrete exits at a distal end of the conveying line. The concrete pump is equipped with a control unit, wherein the control unit is designed to process a measured value via a state variable of the concrete pump in order to generate a control signal on the basis of which the volume flow of the liquid concrete flowing from the liquid concrete supply into the pre-filling tank is adjusted.

[0034] The disclosure includes further developments of the method with features described in connection with the concrete pumping system according to the invention. The disclosure includes further developments of the concrete pumping system with features described in connection with the method according to the invention.

[0035] The invention also relates to a computer program product or a set of computer program products comprising program parts which, when loaded into a computer or into interconnected computers connected to a device according to the invention, are designed to carry out the method according to the invention.

[0036] The invention is described below by way of example with reference to the accompanying drawings using advantageous embodiments. They show:

[0037] Fig. 1: a concrete pump vehicle with a boom arm in the folded state;

[0038] Fig. 2: the concrete pump vehicle from Fig. 1 with the boom arm unfolded;

[0039] Fig. 3: a schematic representation of components of a concrete pump according to the invention;

[0040] Fig. 4: Elements from Fig. 3 in greater detail;

[0041] Fig. 5: a truck mixer of a concrete pumping system according to the invention; Fig. 6: a schematic representation of the functioning of a concrete pumping system according to the invention;

[0042] Fig . 7 : a representation of the time course of the

[0043] Carrying out the method according to the invention;

[0044] Fig . 8 : the view according to Fig . 6 in an alternative

[0045] Embodiment of the invention;

[0046] Fig. 9: Components of a concrete pump according to the invention

[0047] System in an alternative embodiment of the invention;

[0048] Fig. 10, 11: the view according to Fig. 6 in an alternative embodiment of the invention.

[0049] A truck 14 shown in Fig. 1, together with a truck mixer 40 shown in Fig. 5, forms a concrete pump system according to the invention. The truck mixer 40 carries a storage container 41 on its loading area, which can be rotated by a mixer motor 42. The storage container 41 is filled with liquid concrete and, in one embodiment, forms a liquid concrete supply within the meaning of the invention. By varying the direction of rotation and the rotational speed of the storage container 41, the volume flow of liquid concrete that emerges from the storage container 41 via a discharge chute 33 can be adjusted.

[0050] The truck mixer 40 and the truck 14 are positioned relative to one another in such a way that the liquid concrete is poured from the discharge chute 33 of the truck mixer 40 into a pre-filling container 16 of the truck 14. According to Fig. 4, the discharge chute 33 is arranged above the pre-filling container 16 so that the liquid concrete falls from the discharge chute 33 into the pre-filling container 16 under the influence of gravity. A sieve 35 rests on the upper edge 34 of the pre-filling container 16 and can be vibrated using a vibrating drive 38. The liquid concrete falling from the discharge chute 33 strikes the sieve 35 and passes through the sieve 35, while unacceptably large grain sizes or foreign bodies are sieved out. The sieve 35 is designed so that only grain sizes suitable for the dosing pump 36 can pass through. For example, the sieve can be designed so that only grains up to a size of 8 can pass through.The liquid concrete in the pre-filling container 16 is thus less coarse-grained than conventional liquid concrete, which can, for example, contain grains up to a grain size of 32.

[0051] The truck 14 is equipped with a concrete pump 15 which pumps liquid concrete from the pre-filling container 16 through a delivery line 17. The delivery line 17 extends along a boom arm 18 which is rotatably mounted on a slewing ring 19. The boom arm 18 comprises three boom arm segments 20, 21, 22 which are connected to one another in an articulated manner. By pivoting the boom arm segments 20, 21, 22 relative to one another via the joints, the boom arm 18 can be moved between a folded state (Fig. 1) and an unfolded state (Fig. 2). The delivery line 17 extends beyond the distal end of the third boom arm segment 22 so that the liquid concrete can be applied in an area remote from the concrete pump 15.

[0052] The concrete pump 15 is designed for 3D printing so that a mold can be built directly from the concrete emerging from the delivery line 17 without the need for formwork. For this purpose, the concrete pump 15 comprises, as shown in Fig. 3, a metering pump 36 with which the liquid concrete is conveyed so that it emerges from the delivery line 17 as a continuous strand. The distal end of the delivery line 17 is formed by a print head 37 from which the strand emerges with a predetermined cross-sectional profile. Using a positioning system (not shown), the print head 37 can be moved along predetermined paths in order to deposit the strand as a layer of concrete along a route predetermined by a plan.

[0053] The concrete pump 15 comprises a pumping device 29 which is designed as a double-piston pump. The pumping device 29 comprises a first delivery cylinder and a second delivery cylinder 32 which, in an alternating cycle, suck in liquid concrete from the pre-filling container 16 and deliver it along the delivery line 17. The pumping device 29 is equipped with an S-pipe 30 which, in a first switching state, establishes a connection between the first delivery cylinder and an inlet of the delivery line 17 and which, in a second switching state, establishes a connection between the second delivery cylinder and the inlet of the delivery line 17. Liquid concrete delivered by the pumping device 29 through the S-pipe flows into the delivery line 17 and is moved from the proximal to the distal end of the delivery line 17.

[0054] The pumping device 29, which according to Fig. 6 comprises the feed cylinders 45 and a pump drive 46, is operated in a closed control loop with the aim of keeping the pressure of the liquid concrete 43 at the inlet of the metering pump 36 at a constant value. For this purpose, a measured value of the pressure of the liquid concrete 43 at the inlet of the metering pump 36, obtained with a pressure sensor 48, is fed to a control unit 44 of the concrete pump system, and the pump drive 46 is controlled via a pump control 47 such that the power of the pump drive 46 is increased in order to counteract a reduction in the pressure at the metering pump 36, and vice versa.

[0055] A working cycle of the pumping device 29 comprises the steps that, in a state in which the S-pipe 30 forms a connection between the first delivery cylinder and the delivery line 17, the first delivery cylinder delivers liquid concrete from the interior of the first delivery cylinder into the S-pipe 30 with a forward movement. In parallel, the second delivery cylinder sucks liquid concrete from the pre-filling container 16 with a backward movement. With a drive unit 31 (Fig. 4), the S-pipe 30 is switched via a shaft 39 into a second switching state in which the S-pipe 30 forms a connection between the second delivery cylinder and the delivery line 17. After switching, the second delivery cylinder delivers liquid concrete into the S-pipe 30 with a forward movement, while the first delivery cylinder sucks liquid concrete from the pre-filling container 16.

[0056] A flow chart which specifies the sequence of the 3D printing process is stored in a memory chip 49. The information from the flow chart is fed to the control unit 44 via a first data input 50. Via a second data input 51, the control unit 44 receives the target speed at which the printing process should run, i.e. at which the print head 37 should be moved while the concrete strand emerges. Using this information, the control unit 44 controls a drive 52 of the inline pump 36 and thus specifies the speed at which the concrete strand emerges from the print head 37.

[0057] Based on this information, the control unit 44 further determines a target value 53 for the fill level of the pre-filling container 16 of the concrete pump 15. As will be explained in more detail with reference to Fig. 7, the target value 53 for the fill level of the pre-filling container 16 varies over time. Three operating phases 54, 55, 56 are shown. In the first operating phase 54, a first layer of concrete is poured; in the second operating phase 55, no concrete emerges from the pressure head 37; and in the third operating phase 56, a second layer of concrete is poured. A first curve 57 indicates the quantity of liquid concrete emerging from the pressure head 37. A second curve shows the volume flow 58 which flows from the truck mixer 40 into the pre-filling container 16 of the concrete pump 15.The volume flow 58 is high before the start of the first operating phase 54, with the result that the fill level 59 of the pre-filling container 16 rises and reaches a maximum at the start of the first operating phase 54, which maximum corresponds to a first target value 53 for the fill level 59. At the start of the first operating phase 54, the pumping device 29 of the concrete pump 15 is started up, so that liquid concrete is sucked in from the pre-filling container 16, while at the same time the volume flow from the liquid concrete supply 41 drops to zero. This leads to a falling fill level 59 of the pre-filling container 16, which reaches a minimum shortly before the halfway point of the first operating phase 54. The minimum corresponds to a second target value 53 for the fill level 59 of the pre-filling container 16.After reaching the minimum, the setpoint 53 is reset to a higher value, so that a high volume flow 58 of liquid concrete is again supplied to the prefill tank 16 and the fill level 59 rises again to a maximum, which forms a third setpoint within the meaning of the invention. Upon reaching the maximum, the volume flow 58 drops back to zero, and the fill level 59 drops back to a minimum value until the end of the first operating phase.

[0058] The fill level of the pre-filling container 16 is determined by a fill level sensor 60, the measured values ​​of which are fed to a differential element 61, with which the difference between the measured value and the target value 53 is determined. Based on the difference, a fill level controller 62 controls a signaling device 63, so that the signaling device 63 indicates whether the volume flow 58 for the pre-filling container 16 should be increased, remain constant, or be reduced. The fill level controller 62, which is shown as a separate block in Fig. 6 for the sake of clarity, forms an element of the control unit 44. The driver 64 of the truck mixer 40 controls the mixer motor 42 of the storage container 41 based on the signal shown by the signaling device 63, so that it delivers more or less liquid concrete 43 and the volume flow 58 entering the pre-filling container 16 increases or decreases accordingly.In order to provide for the case that the driver 64 of the truck mixer 40 does not react sufficiently precisely to the signaling device 63, the discharge channel 33 can be provided with a dosing device in order to be able to additionally influence the volume flow in the direction of the pre-filling container 16.

[0059] Fig. 8 shows an alternative embodiment in which a signal transmitter 65 is connected to the fill level controller 62, which signal transmitter directly controls the mixer motor 42 of the storage container 41 of the truck mixer 40. This requires an interface between the control unit 44 of the concrete pump 15 and the truck mixer 40, via which interface control signals can be transmitted while the truck mixer 40 and the concrete pump 15 are operated as a concrete pump system according to the invention. The direct signal path between the signal transmitter 65 and the truck mixer 40 makes it possible to avoid inaccuracies which could result, for example, from a lack of attention on the part of the driver of the truck mixer 40.

[0060] In the alternative embodiment in Fig. 9, a chute 66, which forms a buffer device according to the invention, is arranged between the discharge chute 33 of the truck mixer 40 and the pre-filling container 16 of the concrete pump 15. The chute 66 is provided with an outlet flap 67, the position of which can be changed using a stepper motor 68. The volume flow of liquid concrete that flows into the pre-filling container 16 changes depending on the position of the outlet flap 67. The chute 66 comprises a sensor 70, which determines the fill level of the chute 66. The chute 66 is filled with liquid concrete using the discharge chute 33 of the truck mixer 40. According to Fig. 10, the level controller 62 controls the stepper motor 68 of the outlet flap 67 of the chute 66 in order to adjust the volume flow 58 of the liquid concrete entering the pre-filling container 16.The regulation of the volume flow 58 via a chute 66 specially adapted to the requirements of the concrete pump system according to the invention enables a higher precision in the adjustment of the volume flow than a procedure which depends on the accuracy of a dosing device of the truck mixer 40.

[0061] In a second control loop, a mixer controller 69 processes the difference between a fill level of the chute 66 determined by the sensor 70 and a setpoint value for the fill level received from the control unit 44 in order to control the mixer motor 42 of the storage container 41 of the truck mixer 40. In this way, it can be ensured that there is always sufficient liquid concrete 43 in the chute 66 to be able to provide the desired volume flow 58 in the direction of the pre-fill container 16.

[0062] The embodiment in Fig. 11 corresponds to Fig. 10, with the difference that the mixer motor 42 is not directly controlled, but rather the driver 64 of the truck mixer 40 receives a signal according to which he manually adjusts the volume flow exiting the truck mixer 40. This enables the use of conventional truck mixers 40 in a concrete pump system according to the invention.

Claims

Patent claims 1. A method for operating a concrete pump system, in which liquid concrete (43) is introduced from a liquid concrete supply (41, 66) into a pre-filling container (16) of a concrete pump (15), wherein the liquid concrete (43) is sucked out of the pre-filling container (16) by a pumping device (29) and is conveyed along a conveying line (17) so that the liquid concrete (43) emerges at a distal end of the conveying line (17), wherein the concrete pump (15) is equipped with a control unit (44), wherein a measured value via a state variable of the concrete pump is fed to the control unit (44), and wherein the measured value is processed in the control unit (44) in order to generate a control signal on the basis of which the volume flow (58) of the liquid concrete (43) flowing from the liquid concrete supply (41, 66) into the pre-filling container (16) is adjusted.

2. Method according to claim 1, wherein the measured value represents the fill level of the pre-fill container (16).

3. Method according to claim 1 or 2, wherein a signaling device (63) is actuated with the control signal.

4. Method according to one of claims 1 to 3, wherein the control signal controls a dosing device (42, 67) which is designed to adjust the volume flow (58) of the liquid concrete (43) passing from the liquid concrete supply (41, 66) into the pre-filling container (16).

5. The method according to claim 4, wherein the dosing device (42) is an integral part of a system component (40) with which the liquid concrete supply (41) is provided.

6. Method according to one of claims 1 to 5, wherein between a storage container (41) filled with liquid concrete and a buffer device (66) is arranged in the pre-filling container (16), and wherein the dosing device (67) is an element of the buffer device (66).

7. The method according to claim 6, wherein the buffer device (66) is equipped with a fill level sensor (70).

8. Method according to claim 6 or 7, wherein the volume flow of liquid concrete passing from the storage container (41) into the buffer device (66) is adjusted depending on the fill level of the buffer device (66).

9. Method according to one of claims 1 to 8, wherein a target value for the fill level of the pre-filling container (16) is processed in the control unit (44).

10. The method according to claim 9, wherein the setpoint value for the fill level of the pre-filling container (16) is varied within a time period (54, 56) within which a single concrete layer of a 3D printing process is produced.

11. The method according to claim 10, wherein during a middle phase of the 3D printing process with which a single concrete layer is produced, the setpoint value for the fill level of the pre-fill container (16) is low.

12. Concrete pumping system, comprising a concrete pump (15) and a liquid concrete supply (41, 66), wherein during operation of the concrete pumping system liquid concrete (43) is pumped from the liquid concrete supply (41) is introduced into a pre-filling container (16) of the concrete pump (15), wherein the concrete pump (15) comprises a pumping device (29) for sucking liquid concrete (43) from the pre-filling container (16) and conveying it along a conveying line (17) so that the liquid concrete (43) exits at a distal end of the conveying line (17), wherein the concrete pump (15) is equipped with a control unit (44), wherein the control unit (44) is designed to process a measured value via a state variable of the concrete pump (15) in order to generate a control signal on the basis of which the volume flow (58) of the liquid concrete (43) passing from the liquid concrete supply (41) into the pre-filling container (16) is adjusted.

13. Computer program product or set of computer program products, comprising program parts which, when loaded into a computer or into interconnected computers connected to a concrete pumping system according to the invention, are designed to carry out the method according to the invention.

Images