DE202019004672U1 - Compensation device for trouble-free 3D concrete printing using a truck-mounted concrete pump - Google Patents

Abstract

Compensator to compensate for multidimensional fluctuations on the mast tip of a truck-mounted concrete pump placing boom in additive component manufacturing in concrete 3D printing, characterized in that a multidimensionally movable compensation device is arranged between the print head or printhead mouthpiece and the mast tip, with which on the basis of existing position Target and actual data during additive manufacturing unwanted fluctuations in the printhead are compensated for by targeted relative movements, the compensating device being created by the cascaded combination of a slow and a dynamic compensator module to keep the printhead or the printhead mouthpiece steady.

Description

The invention relates to a device for compensating for fluctuations in the mast tip of a truck-mounted concrete pump in order to enable a tolerance-compliant additive in-situ concrete construction method (3D concrete printing) on the construction site.

For additive building or component production on the construction site, it makes sense to use truck-mounted concrete pumps, as shown in [1] as part of the formwork-free in-situ concrete construction process "CONPrint3D" [2]. The mast system of conventional truck-mounted concrete pumps, however, exhibits three-dimensional fluctuations in the range of several centimeters at the mast tip of the placing boom. These fluctuations result e.g. B. from the low rigidity of the moving mast construction and a dynamic excitation from the pumping process or attacking wind loads. If such undefined movements are almost meaningless for the pumping process, they represent a significant problem for additive concrete production. The print head of the 3D concrete printing unit must be guided so smoothly at the jib tip that a freshly manufactured concrete wall, e.g. B. can arise according to the valid flatness tolerances according to DIN 18202.

In the patent literature and doctoral theses (e.g. [3], [4]), various systems and regulations for direct vibration damping or reduction of mast movements can be found on a standard truck-mounted concrete pump. The goal here is usually to minimize the movement of an attached end hose. So far, this has not been enough to add a standard and form-compliant wall according to the applicable flatness tolerances in accordance with DIN 18202 directly on the construction site.

For example, in WO 02/055813 A1 proposed a regulation for damping in particular the last mast member with the aim of limiting the vibration amplitude at the mast tip of preferably 10-20 cm. However, the remaining vibration amplitude is not sufficient for tolerance-compliant wall production using an additive construction site process.

DE 195 03 895 A1 proposes a fixed position control loop for stabilizing the end hose at the end of the mast, which works within a predetermined range of variation with respect to a fixed horizontal reference plane. However, the sensors required for the proposed control only allow a delayed reaction of the control elements to the detected faults, so that a sufficient control quality cannot be achieved.

WO 02/25036 A1 uses a modeled dynamic damping signal connected to a proportional changeover valve, which is filtered, phase-shifted and / or amplified above a defined cut-off frequency (depending on the mechanical natural frequency of the mast arm) in the range of 0.2 to 10 Hz from the time-dependent differential pressure measurement on the associated double-acting arm cylinder supposed to reduce mast movements. Without a higher-level position control, this system tends to undesirably drift the mast tip.

To measure the height of the mast tip with EP 1 537 282 B1 a method is known which works with inclination sensors attached to all mast segments. However, inclination sensors typically used cannot differentiate between a change in the inclination and a translational acceleration of the sensor, as a result of which incorrect measurement values arise in dynamic applications.

WO 2016/131977 A1 presents on the basis of the associated dissertation [3] methods for the measurement of mast dynamics and their use in control technology with the aim of reducing the vertical movement of the mast tip of a truck-mounted concrete pump during pump operation. For this purpose, inertial sensors each consisting of a two-axis acceleration sensor and a rotation rate sensor arranged orthogonally to the acceleration measurement axes are advantageously arranged in the middle of each mast segment or at the mast tip of the last mast arm. Alternatively, an inertial sensor in the form of an acceleration sensor on the mast tip in combination with angle sensors on each articulated joint of the mast system should suffice. With the aim of determining the mast tip position as precisely as possible, the measurement signals are processed, for example, with an extended Kalman filter or complementary filters. The vibration damping with position control of the mast tip should then take place via the hydraulic valves of the actuators of the individual mast joints. In order to ensure high-performance control, an alternative hydraulic concept for truck-mounted concrete pumps was developed in WO 2014/165888 A1 suggested. As a result of the dissertation [3], however, disturbances in the centimeter range at the top of the mast remain in the simulation studies carried out. The practical implementation of the strategies presented is not known until the registration of the existing property right.

Furthermore, with WO 2016/180759 A1 a property right known, which describes a method for controlling a multi-armed articulated mast, in which the immobilization of the mast tip during operation should be possible with a high control quality. The position of the mast tip can be kept calm at a fixed location in the work area in accordance with the user requirements. This is achieved by engaging at least one drive unit. Unwanted swinging movements of the mast tip from the so-called basic movement of the multi-arm articulated mast are detected and reduced by motion sensors by implementing a controlled rotational movement of the outer mast arm in relation to a mast arm located further inside. The compensatory rotary movement is calculated on the basis of measured accelerations from the basic movement using a mathematical mast model which contains the kinematics and dynamics of the mast arm used. In the associated dissertation [4] it is shown that the implementation of the method shows strong vibration minimization as well as high robustness against external influences, such as additional loads or disturbance variables in the form of external suggestions. However, with this type of regulated movement of the mast tip, short-term disturbances in the range of several centimeters are preserved.

With regard to the disadvantages set out in the prior art, further developments in this area are urgently required in order to enable standardized additive concrete part production with a truck-mounted concrete pump on the construction site. The existing solutions for direct vibration damping on the mast system of conventional truck-mounted concrete pumps are sometimes very complex or complicated to implement. It remains questionable whether it is possible to dampen fluctuations that are sufficient for the additive in-situ concrete construction process (3D concrete printing), especially with a continuously moving mast system.

For this reason, the idea arose to create a device that functions as a movably controllable connection between the fluctuating mast tip of a cantilever arm and the printhead of a 3D concrete printing unit that is to be guided smoothly. When manufacturing concrete components using additive construction site production, the print head on the boom of the concrete pump must be stabilized so that the relevant standards or tolerances of the product accuracy requirements (e.g. according to DIN 18202) can be met.

The object of the present invention is to design an actively compensating system which can compensate for stochastically occurring and dynamically recurring disturbing movements (angular and positional deviations) of the mast tip within a predetermined range and with an appropriate speed or short reaction time. Sufficient path amplitudes and frequency bandwidths must be available for the active counter-movements. In addition, a slim or weight-optimized design is required, which works with as little feedback as possible, so that the elastic mast system does not experience any additional mechanical stimuli. In addition, a way of securely supplying the printhead with concrete must be created. Detecting the position and position of the printhead in the room, including actual-target position comparison, is not the task of the device. In addition, there should be no intervention in the pump control.

The problem to be solved with the complex requirements is achieved according to the invention by a compensating device with the features of claim 1. The advantageous embodiment of the invention is specified in the dependent claims. It should be pointed out that the features listed individually in the claims can also be combined with one another in any desired and technologically sensible manner and thus show further refinements of the invention.

The invention is based on the idea that, for additive building or component production on the construction site according to [1], a truck-mounted concrete pump is used, the last mast arm of which is removed and replaced by components which are necessary for 3D concrete printing.

The environmental and process-related fluctuations at the top of the placing boom ( 20th ) should be dynamically neutralized by appropriate counter-movements of a device with several actuators so that the attached print head ( 21 ) can work within permissible deflections from its target position.

To achieve this, it is proposed according to the invention, between the print head ( 21 ) and the top of the placing boom ( 20th ) to attach a compensation device that can be actively controlled with corresponding degrees of freedom. In particular, according to the invention as a compensator ( 1 ) the multi-dimensionally movable compensating device designated the mast tip ( 20th ) with the printhead ( 21 ) connected to compensate for unwanted disturbances through targeted relative movements.

The movable components of the compensator are preferably controlled by electropneumatic actuators ( 2a ) or an electric stepper motor ( 2 B ) driven. The device is designed as stationary equipment for a standard truck-mounted concrete pump for the additive in-situ concrete construction process ( 3D -Concrete printing) designed on site.

The compensator consists of two modules connected in series (cascaded), which will be explained in more detail below before going into the overall device.

The slow expansion module ( 1a ) regulates low-frequency interference with large paths in three translational spatial directions in the range of several centimeters, preferably of ± 15 cm, around its zero position. Advantageously, at least one rotational degree of freedom can also be controlled with the inertial compensator module in order to be able to dampen pitching vibrations.

A preferred embodiment of the inertial compensator module forms a kinematic system consisting of four two-part swing arms ( 3a , 3b ), each arranged at an angle of 90 ° to each other, a printing material reservoir ( 4th ) with a mobile service platform ( 5 ) for the admission of the printhead ( 21 ) connect. The technical implementation is preferably carried out as a plug and screw construction with a maximum dead weight of 120 kg for moving an assumed payload of up to 40 kg. A scaling of this ratio is not excluded, however, and is possible at any time within the scope of the invention. According to the invention, a swing plane is used as the main movement plane ( 6 ) and the plane orthogonal to it according to the invention as a secondary movement plane ( 7 ) Are defined.

For a three-dimensional mobility of the inertial compensator module ( 1a ), the service platform ( 5 ) two pairs of parallel linear slide guides ( 8th ), which are arranged orthogonally to each other and with the two-part swing arms ( 3rd ) are connected. The connection of the service platform ( 5 ) with the two bipartite swing arms of the main movement plane ( 3a ) takes place via a stud bearing ( 9 ), on a separate linear slide guide ( 8th ). To implement an additional degree of freedom of rotation of the inertial compensator module ( 1a ) are the two two-part swing arms of the secondary movement level ( 3b ) not via stud bearing ( 9 ), but via universal joint bearings ( 10th ), in the same way as those of the main movement level, with the service platform ( 5 ) connected.

The drive of the slow expansion module ( 1a ) is preferably carried out by six electronically controlled pneumatic actuators ( 2a ), four of which are in the main movement plane ( 6 ) and two in the secondary movement level ( 7 ) are arranged. The specification for controlling the electronically controlled pneumatic actuators ( 2a ) is preferably implemented using a calculation model that describes the kinematics of the inertial compensator module ( 1a ) depicts and depending on the target movement of the service platform to be carried out ( 5 ) the time-dependent linear movements of the individual electronically controlled pneumatic actuators ( 2a ) issues.

The dynamic compensator module ( 1b ) especially compensates for higher-frequency disturbances and bumps at the top of the placing boom ( 20th ) from the upstream slow expansion module ( 1a ) cannot be completely eliminated. The dynamic compensator module ( 1b ) a range of motion around its zero position in the range of a few centimeters, preferably of ± 5 cm, within which, however, very quick positioning with a short reaction speed is possible. The compensating movement takes place in a translatory direction across the concrete component ( 23 ).

In order to achieve this, the invention provides for only a minimum of usable weight to be moved by merely moving the position of the printhead mouthpiece ( 22 ) of the 3D concrete printing unit through the dynamic compensator module ( 1b ) is changed. The weight of the remaining components of the print head of the 3D concrete printing unit ( 21 ) is from the slow expansion module ( 1a ) carried.

A preferred embodiment of the dynamic compensator module ( 1b ) forms a unit consisting of a spindle-driven and two linear guides ( 11 ) mounted sledge ( 12th ) which, according to the invention, as a coupling plate ( 13 ) designated mounting plate is mounted. The sled ( 12th ) serves as a holder for the printhead mouthpiece ( 22 ). A central opening in the slide and the coupling plate creates a supply option for concrete to the printhead mouthpiece ( 22 ).

The drive spindle ( 14 ) is preferably powered by an electric stepper motor ( 2 B ) emotional. Constructively arranged counterweights ( 15 ) ensure a smooth run of the sled ( 12th ). The dead weight of the dynamic compensator module ( 1b ) is advantageously less than 10 kg for moving an assumed printhead mouthpiece of up to 4 kg. A scaling of this ratio is not excluded, however, and is possible at any time within the scope of the invention.

From the combination of the sluggish ( 1a ) and dynamic compensator modules ( 1b ) creates a multi-dimensional compensation device, which according to the invention acts as a compensator ( 1 ) referred to as. The two compensator modules are connected via the print head of the 3D concrete printing unit ( 21 ), which is at the bottom of the service platform ( 5 ) of the slow expansion joint module ( 1a ) is arranged and the coupling plate ( 13 ) of the dynamic compensator module ( 1b ) in the way that advantageously the direction of movement of the carriage ( 12th ) from the dynamic compensator module ( 1b ) always across the discharge direction of the print material at the print head mouthpiece ( 22 ) for the concrete component to be manufactured ( 23 ) can be done. To do this, the print head of the 3D concrete printing unit ( 21 ) mandatory one Include rotating device, which is not part of the present invention.

The printhead ( 21 ) or its mouthpiece ( 22 ) can thus on the fluctuating mast tip of the placing boom during work ( 20th ) of a truck-mounted concrete pump are kept so stable that a continuous additive manufacturing of concrete components ( 23 ) can be carried out on site within the necessary tolerances. Further aspects of the device, such as short reaction times or fast compensatory movements in combination with large stroke distances and the most exact positioning possible, can be fulfilled.

A calculation algorithm divides the necessary movement components across the concrete component ( 23 ) preferably depending on the required size and speed of compensation between the actuators of the slow 1a ) and dynamic compensator modules ( 1b ) on. A flexible connection ( 16 ), preferably as an elastically stretchable hose, enables concrete to flow from the printing material reservoir ( 4th ) to the printhead ( 21 ) or to the printhead mouthpiece ( 22 ).

The compatible connection between the compensator ( 1 ) and the top of the placing boom of the truck-mounted concrete pump ( 20th ) takes place via the printing material reservoir (4) of the slow expansion joint module ( 1a ).

To influence the reaction forces on the placing boom due to the necessary movements of the compensator ( 1 ) are symmetrical according to the invention on the printing material reservoir ( 4th ) arranged spinning top ( 17th ) which rotate in opposite directions at a constant speed and a simple rotary bearing ( 18th ) at an angle of 90 degrees to the gyro rotation axis ( 19th ) own. With the gyro precession, jerky movements at the print material reservoir ( 4th ) can be significantly reduced as a result of acting forces.

• 1 zeigt schematisch den grundsätzlichen Aufbau des trägen Kompensatormodules (1a) mit den definierten Bewegungsebenen.
• 2 zeigt schematisch ein Detail des trägen Kompensators, um die Verbindungen der zweigliedrigen Schwingenarme (3a, 3b) mit den Linear-Schlittenführungen (8) auf der Serviceplattform (5) darzustellen.
• 3 zeigt schematisch den grundsätzlichen Aufbau des dynamischen Kompensatormodules (1b). Hier wird als Stellglied ein elektrischer Schrittmotor (2b) eingesetzt.
• 4 zeigt schematisch den Kompensator (1) als Ergebnis der Zusammenschaltung des trägen und des dynamischen Kompensatormodules in Kombination mit weiteren Komponenten, die zum 3D-Beton-Druck notwendig sind.
• 5 zeigt schematisch die Anordnung, Drehlagerung und Rotationsrichtung von Kreiseln (17) am Druckmaterial-Reservoir (4) im Detail.

The invention is explained in more detail below by way of example with reference to the accompanying drawings.

• 1 shows schematically the basic structure of the slow expansion joint module ( 1a ) with the defined movement levels.
• 2nd shows schematically a detail of the inertial compensator to the connections of the two-link swing arm ( 3a , 3b ) with the linear slide guides ( 8th ) on the service platform ( 5 ).
• 3rd schematically shows the basic structure of the dynamic compensator module ( 1b ). An electrical stepper motor ( 2 B ) used.
• 4th shows schematically the compensator ( 1 ) as a result of the interconnection of the slow and dynamic compensator module in combination with other components that are necessary for 3D concrete printing.
• 5 shows schematically the arrangement, rotation and direction of rotation of gyros ( 17th ) on the print material reservoir ( 4th ) in detail.

Non-patent literature cited

1. [1] Näther, Mathias, et al .: concrete 3D -Print - feasibility studies for continuous and formwork-free construction processes 3D -Forming fresh concrete. Stuttgart: Fraunhofer IRB Verlag, 2017. ISBN 978-3-7388-0028-9.
2. [2] Dresden, Technical University: CONPrint3D. AKZ 3020160145494 . 13 . May 2016. Word-figurative mark.
3. [3] Henikl, Johannes: Control strategies for the boom of a truck-mounted concrete pump. Aachen: Shaker Verlag, 2016. ISBN 978-3-8440-4541-3.
4. [4] Zorn, Sophie: Model-based active vibration damping of a multilink manipulator. [On-line] 18th . 04 . 2018. https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa-234001.

Reference list

(1)

Compensator

(1a)

Inert compensator module

(1b)

Dynamic compensator module

(2a)

electronically controlled pneumatic actuator

(2 B)

electric stepper motor

(3a)

two-part swing arm of the main movement plane

(3b)

two-part swing arm of the secondary movement level

(4)

Media reservoir

(5)

Service platform

(6)

Main movement plane

(7)

Secondary movement level

(8th)

Linear slide guide

(9)

Stud bearing

(10)

Universal joint bearing

(11)

Linear guide

(12)

carriage

(13)

Coupling plate

(14)

Drive spindle

(15)

Counterweight

(16)

Flexible connection

(17)

Spinning top

(18)

Easy pivoting

(19)

Rotary axis of rotation

(20)

Mast tip of the placing boom of the truck-mounted concrete pump

(21)

Printhead of 3D - concrete printing unit

(22)

Print head mouthpiece

(23)

Concrete component

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 02/055813 A1 [0004]
• DE 19503895 A1 [0005]
• WO 0225036 A1 [0006]
• EP 1537282 B1 [0007]
• WO 2016/131977 A1 [0008]
• WO 2014/165888 A1 [0008]
• WO 2016/180759 A1 [0009]

Claims (4)

Compensator to compensate for multidimensional fluctuations on the mast tip of a truck-mounted concrete pump placing boom in additive component manufacturing in concrete 3D printing, characterized in that a multidimensionally movable compensation device is arranged between the print head or printhead mouthpiece and the mast tip, with which on the basis of existing position Target and actual data during additive manufacturing unwanted fluctuations in the printhead are compensated for by targeted relative movements, the compensating device being created by the cascaded combination of a slow and a dynamic compensator module to keep the printhead or the printhead mouthpiece steady. Compensator after Claim 1 , characterized in that, on the one hand, the inertial compensator module compensates for low-frequency disturbances with large paths in the three translational spatial directions and a pitching vibration of the truck-mounted concrete pump boom, and on the other hand, the dynamic compensator module compensates for higher-frequency disturbances and impacts in a translational direction across the concrete component. Compensator after Claim 1 characterized in that rotors are arranged symmetrically on the printing material reservoir to reduce jerky movements, rotate in opposite directions at constant speed and have a simple and free rotary bearing at an angle of 90 degrees to the gyro rotation axis. Compensator after Claim 2 , characterized in that a calculation algorithm divides the necessary movement shares across the manufacturing concrete component between the actuators of the inertial compensator module and the dynamic compensator module.

Images