EP1937913A1

EP1937913A1 - Working mast, in particular for large manipulators and movable concrete pumps

Info

Publication number: EP1937913A1
Application number: EP06806319A
Authority: EP
Inventors: Stephan Gelies; Jürgen BRAUN
Original assignee: Putzmeister Concrete Pumps GmbH
Current assignee: Putzmeister Engineering GmbH
Priority date: 2005-10-18
Filing date: 2006-10-17
Publication date: 2008-07-02
Also published as: EA200801112A1; KR20080069599A; WO2007045426A1; EA013204B1; JP2009511395A; CN101292072A; US20080217279A1

Abstract

The invention relates to a working mast, in particular for large manipulators and concrete pumps comprising a rotatable head (21) mounted on a frame (11) in such a way that it is pivotable about a vertical axis (13), a first mast arm (1) pivotable in a limited manner about a horizontal articulation axis (A) in front of the rotatable head (21) by means of a drive unit (22) and at least one other mast arm (2, 3, 4) which, is longitudinally displaceable along a thrust axis and/or rotatable about a horizontal articulation axis (B, C, D) with respect to the adjacent mast arm with the aid of a drive unit (23, 24, 25). In addition, a control, preferably a remotely controlled, device enables the mast to be displaced by means of actuators associated with different drive units. The actuators are substantially embodied in the form of adjusting valves which make it possible to control the drive units (23, 24, 25) embodied in the form of hydraulic cylinders. A path and/or angle measuring sensor (54) is placed on at least one mast arm, thrust and/or articulation axis, the vertical axis (13) and/or drive units (23, 24, 25). The control device comprises a safety routine responsive to output data items received from the sensors. Pressure and force sensors (42, 44) are arranged on the bottom and rod sides of at least one drive unit embodied in the form of a hydraulic cylinder (22), whereas the safety routine comprises an evaluating part (56) responsive to the output data of the pressure and force sensors. In order to improve the use of kinematics during the articulated mast movement, the safety routine is provided with a data memory for recording a data field which is analytically predefined or presented in the form of tables and contains the pressure or force threshold values corresponding to at least one path and/or angle measured value assigned to the mast arm. The evaluating part (56) comprises a comparator supplied with output data of the pressure or force sensors (42, 44) or the associated path or angle sensors (54) or else with quantities derived therefrom in order to compare them with the associated threshold values obtained from the data field and to generate a signal when said threshold value data items are exceeded or fallen bellow.

Description

Work mast, especially for large manipulators and mobile concrete pumps

description

The invention relates to a work pole of the type specified in the preamble of claims 1 and 2.

Known working masts of this type consist essentially of a rotatable about a vertical axis on a frame rotary head, a first about a horizontal bending axis relative to the rotary head limited by a drive unit pivotable boom and at least one relative to an adjacent boom arm by means of an associated drive unit along a shear axis longitudinally displaceable and / or another mast arm pivotable about a horizontal bending axis. For the mast movement a preferably remote-controllable control device is provided which has the individual drive units associated with actuators. In addition, at least one sensor for displacement or angle measurement is provided, which is associated with at least one of the mast arms, the shear or bending axes, the vertical axis and / or the drive units. Furthermore, pressure or force sensors are arranged at the bottom and / or rod end of at least one of the drive units designed as a hydraulic cylinder. The output data of the at least one sensor for displacement or angle measurement and the pressure and force sensors are evaluated in an evaluation unit of a safety routine in the course of a mast movement.

Work masts of this type are preferably used in large manipulators, in truck-mounted concrete pumps with buckling and telescopic masts and in mobile telescopic conveyors. Truck-mounted concrete pumps are usually operated by an operator who, via a remote control device, is responsible for both the pump control and the positioning of the end hose located at the top of the articulated mast. For this purpose, the operator has to actuate several rotational degrees of freedom of the articulated mast via the associated drive units while moving the articulated mast in the non-structured three-dimensional work space while observing the site boundary conditions. To facilitate handling in this regard, an actuator has already been proposed (DE-A 43 06 127), in which the redundant bending axes of the articulated mast are controlled in each rotational position of the mast independently of the axis of rotation with a single control operation of the remote control body together. A basic prerequisite for such an actuation of the articulated mast is a position control, which includes, inter alia, a sensor for path or angle measurement assigned to the individual boom arms, articulated axles and / or drive assemblies. Since failures in technical systems of this type, which include both mechanical, as well as electronic and hydraulic components, can not be completely ruled out, it requires a security monitoring, which warns the operator and intervenes in the functional sequence. For this purpose, it is necessary to detect the errors occurring sensorially and evaluate with the aim of avoiding unwanted errors and damage. Safety devices of this type have already been used in connection with the position control within the articulated mast (DE-A 101 07 107), for example, the on state of the feed valve, the presence or absence of Fahrvorgaben via the remote control, the occurrence of away or angle-related excessive control deviations or Increased speeds of such deviations and respond to excessive angular velocities.

The aim of the present invention is to extend the safety monitoring to a monitoring of the limit loads in terms of strength and stability. This problem occurs, for example, with articulated masts on, the mast arms are folded in the folded state in the manner of an overhead roll folder. Although overhead roller folders have the advantage that unfolding of the mast pack is relatively easy and quick. In contrast to other types of folding, the mast pack resting on the chassis in the driving state with its first mast arm can be lifted around the bending axis A in the first quadrant and then pivoted into the working area after the second quadrant. When unfolding occur here, however, problems, mainly because of the fact that the first boom arm is operated by a hydraulic cylinder whose cylinder are articulated on the mast arm and the piston rod to a bell crank of the turret. This means that when the first mast arm is raised, the hydraulic cylinder is subjected to rod-side pressure oil, so that a correspondingly high pressure is required to generate the necessary force due to the smaller piston surface designed as an annular surface. In addition, strength problems can occur at the fixed point of the piston rod in the region of the piston. Since the rest of the mast set rests on the first mast arm, a deployment strategy is necessary for reasons of strength in order to be able to lift the first mast arm. Furthermore, for geometric reasons, it should be borne in mind that the arm package of an overhead roll folder in the folded-up state extends beyond the driver's cab. When lifting, therefore, the arm package must first be released so that there is no collision with the cab. For this reason, a pivoting of the Restarmpakets is necessary to the bending axis B, by a certain angle of for example 20 °. Only then can the first mast arm be raised to a critical angle of approximately 65 ° with the residual arm package still folded around the A joint. In conventional systems, there is a limit switch, which, in the operating state regardless of the position of the other mast arms for reasons of strength and stability ensures that the critical angle of 65 ° of the first mast arm is not exceeded. When swinging the rest arm package, it must be taken into account for the same reason that the boom arm 2 may also be vertically aligned, which results in an angular movement. - A - position relative to the arm 1 of about 155 ° corresponds. Also on the boom arm 2 is a limit switch, which ensures that the boom arm 2 is vertical in the extreme case. The vertical position is switched, for example, via a trained as a mercury switch tilt switch. The upper mast arms, however, are limited only by constructive limitations in their swivel range. Accordingly, the mast arm 3 with a pivoting range of 180 ° in the case of a vertical standing of the arm 2 will be aligned vertically.

When using predetermined limit switch is felt to be disadvantageous that the A-joint can not be driven in the operating state at the angle of 65 °, which is perceived as an obstacle in certain concreting tasks. The same applies to the B-joint, since vertical positioning is not always the ideal position for the concreting process. These guidelines have proved to be too rigid. They do not fully exploit the possibilities of kinematics, but limit the movement of the mast in a way that is clear but not always practical.

Proceeding from this, the present invention seeks to provide a design principle, whereby the rigid limits canceled in the operation of a work mast and a more flexible handling and driving ability of the mast arms is guaranteed.

To solve this problem, the feature combination specified in claim 1 is proposed. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The solution according to the invention is based on the idea that the safety device comprises a suitable sensor system for the continuous determination of position and force measured values within the working mast, as well as a Having a safety routine that sets the measured values under the criterion of compliance with specified limits for strength and / or stability of the system to each other. In addition, the design of the pump with regard to the maximum achievable pump pressure plays a role. Since the limit values for strength and stability depend significantly on the instantaneous mast configuration and thus on the instantaneous position and angle measurement values of the individual mast arms, the limit values required for safety monitoring can be specified in analytical form or as tables by evaluating the kinematic conditions. Accordingly, it is primarily proposed according to the invention that the safety routine comprises a data memory with an analytically or in a table form prescribed data field of pressure or force limits in response to at least one of the mast arms associated path or angle measurements, and that the evaluation unit has a comparator with Output data of the pressure or force sensors and the associated displacement or angle sensors or variables derived therefrom for performing a comparison with associated limit value data from the data field and for triggering a signal when the limit value is undershot or exceeded.

According to an advantageous embodiment of the invention, the displacement sensor is arranged on the associated, designed as a hydraulic cylinder drive unit of the mast arm. Alternatively, the angle sensor is arranged in the region of the bending axis of the associated mast arm.

In order to additionally include the stability in the monitoring system, which is particularly important in a one-sided narrow support of the buckling mast supporting chassis, it is proposed according to a preferred embodiment of the invention that another displacement or angle sensor on the drive unit or on the axis of rotation of the Turret is arranged and that stored in the data memory of the safety routine analytically or in a tabular form data field from printing or Force limits additionally correlated with the rotary head associated displacement or angle measurements.

A further preferred embodiment of the invention provides that geodesic angle sensors are arranged on the mast arms for determining earth-fixed angle measured values assigned to the individual mast arms. In addition, a further geodesic angle sensor can be provided on the turret and / or on the frame for measuring at least one earth-constant angle value associated with the turret or the frame. In this case, the software routine expediently has a coordinate transformer for converting earth-fixed, arithmetic-related angle measurement values into buckling angles of the individual boom arms.

A further advantageous embodiment of the invention provides that at least one of the actuators responds to the signal triggered by the safety routine when limiting data is exceeded while a safety movement or a safety stop is being executed.

In accordance with a further preferred development of the invention, the control device comprises a position controller, which responds to the path or angle measurements, for the mast movement.

A further advantageous embodiment of the invention provides that the control device comprises a vibration damper for the boom arms of the distributor boom which responds to the time-dependent path or angle measured values and / or to the pressure or force measured values.

In the foregoing, the invention has been explained above all with reference to a concrete distributor mast designed as an overhead roll folder. The invention is not limited to this embodiment, but can also be used in work poles of other design and application. Here are some examples: A work mast in which the first mast arm can be pivoted by about 90 ° relative to the turret with the aid of the drive unit designed as a hydraulic cylinder. In addition to the concrete distributor masts designed as buckling and / or telescopic masts, these also include telescopic overhead masts for mobile conveyors.

Working masts, in which at the end of the first boom arm, an existing from at least one further mast arm mast boom is pivotally mounted about a horizontal axis. These include, in particular, designed as articulated boom concrete distribution booms.

Work masts in which the first mast arm is connected to a plurality of telescopically mutually longitudinally displaceable mast arms. These include above all telescopic conveyors for wet and

Drying agents.

Work masts, in which at least one of a plurality of horizontal axes about each other pivotable mast arms composite mast boom is articulated at the end of the longitudinally movable mast arms. This mainly includes articulated masts, in which one of the mast arms is telescopic.

Work masts, in which at least one mast arm at a distance from the pivot axis of the first mast arm, a guide roller is arranged, via which a cable is guided with a receiving member for a movable load, wherein on the rope, a pressure or force sensor is arranged, the output with the evaluation part of the safety routine is connected. In such a case, the invention allows a safety monitoring of the work mast, including the load hanging on the rope. In the following the invention will be explained in more detail with reference to the drawing. Show it

Figure 1 is a side view of a truck-mounted concrete pump with a trained in the manner of an overhead roll folder work mast in the folded driving condition.

FIGS. 2a to d show a schematic of a folding strategy of an overhead

Rollfalter with conventional safety device;

3a shows a detail of the mast arm 1 of an overhead

Rollfalter with dimensions for determining the external moment equilibrium (subsystem 1);

3b shows a representation corresponding to FIG. 3a with dimensions for the determination of the internal moment equilibrium (subsystem 2);

4 shows a section through the hydraulic cylinder of the mast arm 1 with dimensions for the calculation of the cylinder force.

Fig. 5 shows two diagrams relating to the limit moment in the joint

A (upper curve) and the permissible cylinder forces (lower curve) as a function of the angle of rotation of the mast arm 1 about the bending axis A;

Fig. 6a an overhead roll folder in the operating state in one

Borderline according to conventional safety criteria;

6b and c show the overhead roller shutter according to FIG. 6a in permissible operating positions according to the safety criteria according to the invention; Fig. 7 is a flowchart of the safety routine;

Fig. 8 shows a detail of the mast arm 1 of a standard concrete distributor mast with maximum bending angle to the

Bending axis A of 90 °;

9 is a side view of a distribution boom of a truck-mounted concrete pump with telescopic boom arm 1;

10 is a partial side view of a work mast with crane function;

Fig. 11a and b is a side view of a conveyor for wet or dry fabrics with turret and telescopic

Working boom.

First, the invention will be explained with reference to the embodiment shown in FIGS. 1, 2a to d and 6a to c of a truck-mounted concrete pump with overhead roll folder.

The truck-mounted concrete pump 10 shown in FIGS. 1, 2a to d and 6a to c comprises a multiaxial chassis 11 with a driver's cab 15, a slurry pump 12 and a work mast 14 rotatable about a vehicle-fixed vertical axis 13 as a carrier for a concrete delivery line (not shown). Liquid concrete, which is continuously introduced into a hopper 17 during concreting, is conveyed via the concrete delivery line to a concreting location remote from the location of the vehicle 11.

The work mast 14 consists of a by means of a hydraulic rotary drive about the vertical axis 13 rotatable rotary head 21 and a pivotable on this articulated mast 20, the variable range and height difference between the chassis 11 and the concreting is continuously adjustable. The articulated mast 20 consists in the illustrated embodiments of four articulated mast arms 1 to 4, which are pivotable about parallel to each other and at right angles to the vertical axis 13 of the rotary head 21 extending buckling axes A to D. The bending angles εi to ε ₄ (FIG. 2d) of the articulated joints formed by the bending axes A to D and their arrangement with respect to one another are coordinated with one another such that the work mast 14 with the space-saving transport configuration on the chassis corresponding to multiple folding as shown in FIG 11 can be stored. The articulated mast 20 forms in the embodiments shown in the drawings an overhead roll folder, wherein the mast arm 1 in the folded state rests directly on the chassis 11 and the remaining mast arms 2 to 4 are rolled helically and in the rolled-up state forward on the cab 15th survive. By activating drive units, which are formed in the embodiments shown in FIGS. 3 and 4 and 6a to c as double-acting hydraulic cylinders 22 to 25, which are individually assigned to the bending axes A to D, the articulated mast 20 is of its folded Transport position unfolded in its unfolded operating position (Fig. 2a to d). The unfolding of the articulated mast 20 is only possible if the chassis 11 is supported on the substrate 30 with two front and two rearward extension legs 26, 28. In confined construction sites, a one-sided narrow support with the Ausstellbeinen 26,28 is possible, which requires additional safety precautions during the unfolding of the buckling mast 20 to avoid a risk of tipping.

The illustrated in the various embodiments, designed as overhead roll folder buckling masts 20 have the advantage that the deployment of the mast pack is relatively easy and quick. In contrast to other folding methods, the package can be lifted around axis A and swiveled from the first quadrant into the working area in the second quadrant. Since on the mast arm 1, the entire rest of the mast pack rests, is the known per se, in Fig. 2a to d deployment strategy shown to raise the boom arm 1 can. This is due primarily to the fact that the remaining arm package extends beyond the cab 15. When lifting must therefore first the arm package in the sense of Fig. 2a and b to the bending axis B by about ₂ = 10 ° to 30 ° and then the arm 1 are raised by a corresponding angle E ₁ so that it no further pivoting Collision in this area gives. In order to avoid overloading, the arm 1 must then be raised about the bending axis A in the sense of FIG. 2c to an angle εi = 65 ° and at the same time the arm 2 to an angle> 90 °, before the further boom arms in the sense of FIG 2c and 2d can be unfolded. In the operating state, in the conventional constructions, the boom 1 is secured by an end switch at an angle εi = 65 °, while the boom 2 can be brought into its vertical position at the outset (FIG. 2d). The vertical position is secured by a tilt switch. The mast arm 3 has only the possibility to be pivoted to ε ₃ = 180 ° in the embodiment shown. Therefore, the mast arm 3 in the case of a vertical standing of the arm 2 will point vertically upwards. Above all, the conventional limits shown in FIG. 2d with regard to the swivel angles εi and t _{2 are} perceived as an obstacle in certain concreting tasks. On the other hand, they do not fully exploit the possibilities of kinematics, but limit the swivel angle in places that are clear but not always practical.

In order to be able to fully exploit the possibilities of kinematics when operating the articulated mast, in addition to the design of the hydraulic pump with regard to the available maximum pump pressure, it is above all the strength at the force-transmitting points of the hydraulic cylinders and the stability of the system supported on the substrate 30. be taken into account. In order to be able to meet the limit criteria with regard to strength and stability, suitable sensor systems are required for monitoring the forces acting in the region of the hydraulic cylinder 22 and the over the unfolded articulated mast 20 on the system attacking torques.

The strength criterion relates primarily to the hydraulic cylinder 22 associated with the bending axis A, whose cylinder 32 is articulated in the region of the axis 34 on the boom arm 1, while the piston rod 36 is articulated in the region of the axle 38 on a deflection lever 50 of the rotary head 21. This means that the cylinder 32 of the mast arm 1 when lifting rod side is pressurized oil. Due to the small piston area a correspondingly higher pressure is required there to generate the cylinder force required for lifting F _Zyl . On the other hand, because of the available limiting pressure of, for example, 380 bar, the hydraulic system can only provide a certain lifting power. In addition, at the fixing point of the piston rod 36 in the region of the piston 37 strength problems can occur. These problems are once taken into account in the unfolding process in the sense described above by a deployment strategy according to FIGS. 2a to d. In order to be able to fully utilize the limits even in the operating state, according to the invention the pressure p _s and p _{B are} monitored at the rod-side and bottom-side end of the hydraulic cylinder 22 by means of pressure sensors 42, 44 and evaluated in an evaluation circuit for determining the instantaneous cylinder force:

FZ "Yi = F? _A - Fs = D _B p ² _B - UD ² - D ₅ ²⁾ - p _s 4 4 (1)

where F _B and F _{s denote} the forces on the bottom and the rod side, p _B , p _s the pressures on the bottom and the rod side, D _B the cylinder diameter and D _s the piston rod diameter.

For reasons of strength, the cylinder force F _Zyl must not exceed a maximum value F max, which takes into account that the welds are in the range of the piston and the buckling forces in the piston and in the cylinder are subject to a maximum load. By comparing the measured and according to formula (1) calculated cylinder force F _cyl with predetermined limits can be monitored via an evaluation circuit 56, the exceeding of the limit force and a corresponding signal 57 are triggered. By the signal 57, for example, an actuation of the buckling mast can be interrupted.

Another limit is the torque M acting on the articulated mast on the entire system, which can affect stability. In the overhead roll folder, these are mainly operations in the neck position of the mast arm 1, in which the above-described safety angle E ₁ of 65 ° is exceeded (arrow 70 in Fig. 6a) and / or in which the mast arm 2 from its vertical position in the Neck position is pivoted (arrow 72 in Fig. 6a). This problem occurs especially in the one-sided narrow support, in which the articulated mast 20 is brought about the vertical axis 13 in a relation to the vehicle longitudinal axis lateral working position.

The kinematic elements necessary for the determination of the moment equilibrium are shown in FIG. 3a for an outer subsystem 1 with the elements turret 21, ArnrWArmpaket 1 and push rod 52 and for an inner subsystem 2 with the elements deflection lever 50, push rod 52 and hydraulic cylinder 22 shown.

In subsystem 1, the external moment equilibrium about the bending axis A of the boom arm 1 can be calculated as follows:

Σ M {axis A) = 0

- F ₀₃ - b + G _arm - a = 0 (2) Here, F _{DS means} the force acting on the push rod 52, while G _{Am means} the weight of the arm package, which acts in the center of gravity 46. The distances a and b define the torque-determining distances from the bending axis A.

From the formula (2), the relation is given

'Arm ^■ α

F DoSs = - (3)

0 The internal moment equilibrium for the subsystem 2 consisting of deflection lever 50, pressure rod 52 and hydraulic cylinder 22 results from FIG. 3b with respect to the axis of rotation 48 of the reversing lever 50 as follows:

Σ M (axis 48) - 0 15 - F _DS - c + F _Zyr d = 0 (4)

where F _{DS is} the force acting on the push rod and F _{Zy /} the cylinder force and c and d are the associated distances from the axis of rotation 48. 0

From the formulas (4) and (3) for the two subsystems 1 and 2, a relationship for the cylinder force F _Zyl can be derived as a function of the weight force G _{arm of} the _arm package and the distance variables a to d:

Taking into account the dependence of the distance variables a to d on the bending angle εi of the mast arm 1 and taking into account additionally the maximum permissible cylinder force F _max for reasons of strength, one obtains one _Limit curve for the cylinder force F _Gnra (εi) in kN according to the curve 1 of the diagram of FIG. 5 as a function of the arm rotation angle (bending angle) εi. Curve 2 shows a limit curve for the permissible load torque M _limit ( ^ε i) ' ⁿ kNm. The permissible cylinder force range is denoted by F in the diagram and M by the permissible load torque range. It should be noted that the horizontal boom arm 1 of the arm rotation angle εi = 0 ° and the vertical boom arm 1 of the arm rotation angle εi = 90 ° corresponds.

In the lower Armdrehwinkelbereich 0 ° to 10 ° results in a relation to the maximum force F _max limited limit range F _Gren :, resulting from the

Reaching a limit for the Umlenkhebelkraft results. The plateau range between 10 ° and 50 ° is determined by the theoretically maximum permissible cylinder force F _maii . Accordingly, a reduced compared to M _max permissible load torque range M _boundary is obtained in the plateau region - For Armdrehwinkeln εi above 50 °, the cylinder force M _Gren, theoretically limited by the permissible loading moment M _max.

The curve 1 is given in tabular form as a data field for the limit value of the cylinder force F _Oren , (ε-ι) and with a software routine (FIG. 7) with the

Measured values F _Zyl , which differed with the help of pressure sensors 42,44

Consideration of the formula (1) and in fact as a function of the respective angle measured value εi, which is determined with the help of one of the bending axis A associated angle or displacement sensor. The angle measured value can be determined via an angle sensor 54 arranged on the bending axis A. In principle, a displacement sensor connected to the piston rod 36 and the cylinder 32 of the hydraulic cylinder 22 can also be used with corresponding conversion of the path data into angle data. A third possibility is to use a geodesic Angle sensor, which is connected to the boom arm 1 and the measured value can be converted into an angle reading about the bending axis A.

The safety device according to the invention thus makes it possible to determine from the sensory measured values P _s , P _B , ε _γ and the cylinder force F _cyl derived therefrom by comparison with the limit values F _Gren , (E ₁ ) in FIG. 5 stored in a data memory in tabular form

F _Cyl ≤ Fa ^ (S ₁ ) (6)

to calculate allowable arm configurations that better exploit the kinematic capabilities of the system. The limit value monitoring explained above is illustrated with reference to FIG. 7 in a flowchart of a safety routine. A further improvement in this regard is achieved by including corresponding limit value tables for further boom arms, in particular the boom arm 2, and corresponding sensors in the area of these boom arms in the safety device.

As a further variable, the rotational position of the articulated mast 20 can be added about the vertical axis 13, which leads to better utilization of the working range of the articulated mast, especially in the border region of the one-sided narrow support.

In FIGS. 6a to 6c, specific expansions of the swiveling range of the boom arms 1 and 2 in the direction of the arrows 70, 72 (FIG. 6a) are indicated as simple examples, which, taking into account the limit value monitoring described above in comparison to the conventional dashed lines (FIG 6b, c) indicated limit angles can be achieved. The sensors provided for the measurement of the pressure and angle values according to the invention also find their application in the computer-controlled actuation of the multi-arm articulated masts 20 with the aid of only one control lever of a remote control (cf., inter alia, DE 101 07 107 A1) and in the vibration damping of articulated masts (cf. DE 100 46 546 A1). The sensor system installed in the system thus has multiple benefits in the various areas of system control and monitoring.

In the foregoing, the invention has been explained in detail with reference to an overhead roll folder as the first embodiment. The ideas underlying the invention can also be applied to a variety of other applications. In the following, this will be explained with reference to the applications shown in FIGS. 8 to 11.

FIG. 8 shows a section of a standard concrete distributor mast whose angle of rotation εi about the bending axis A of the mast arm 1 relative to the rotary head 21 is less than 90 °. The kinematic elements necessary for the determination of the moment equilibrium are shown in FIG. 8 on the basis of FIG. 3a and on the reference numerals given there. For the moment equilibrium, the following relationship follows:

M / m = F _Zy rb

⁷ arm U)

Zyl

Taking into account that the distance variables a and b from the articulation angle εi of the boom arm 1 are dependent, and further considering the reasons of strength, maximum allowable cylinder force F _max, roll moth overhead is obtained similarly to the case of the embodiment previously explained in detail for a limit curve for the cylinder force Fcrenz (εi) as a function of the arm rotation angle (bending angle) εi. Furthermore, a limit curve for the permissible load torque Mcr _e nzfo) can be specified. With these curves can be a stability monitoring in the mast movement in the sine of the above implementations realize.

The exemplary embodiment shown in FIG. 9 is a truck-mounted concrete pump 10 with a concrete distributor boom whose boom arm 1 can be pivoted about the pivot axis A of the rotary head 21 by a pivot angle εi. The mast arm 1 consists of several, mutually telescoping mast segments 1a to 1f, at the end of which a buckling mast boom with several other mast arms 2,3,4,5 connects.

The relevant for the stability monitoring torque balance about the bending axis A of the boom arm 1 leads here to the formula (7).

If one considers the dependence of the distance variables a and b on the bending angle εi of the mast arm 1 and on the position of the other mast arms and additionally takes into account the maximum permissible cylinder force F _max for reasons of strength, one again obtains a limit curve similar to FIG. 5 for the cylinder force Fz _y ι, depending on the arm rotation angle ε- |.

In the embodiment shown in Fig. 10 a detail of a work mast 14, for example, a concrete pump is shown, which also acts as a crane for lifting a load. For this purpose, there is arranged at the distance b from the bending axis A of the mast arm 1 a deflection roller 80, via which a cable 82 is guided with a receiving member 84 for a movable load. In addition, a force sensor 86 for determining the weight G _Las t is arranged on the cable 82, whose output is connected to the evaluation part of a safety routine. About this system, the moment equilibrium is calculated around the bending axis A of the boom arm 1 as follows:

F _cyl ^■ c = G _Am ^■ a + G _load ^■ b

G ⁷ A _Δ m _m - a + G ₁ load (8)

Zyl Taking into account the dependence of the distance variables a, b and c of the angle E ₁ of the boom arm 1 and on the position of the other mast arms and additionally considering the reasons of strength, maximum allowable cylinder force F _MAXL is also obtained here a limit curve for the cylinder force F _G Conference ( εi), which allows stability monitoring.

The exemplary embodiment shown in FIGS. 11a and b is a mobile belt conveyor 90 with a work mast 14 hinged to a turret 21 with mast arms 1a to 1d which can be telescoped relative to one another. The work mast 14 is pivotable about the bending axis A by an angle εi with the aid of a drive unit designed as a hydraulic cylinder 22.

For the determination of the moment equilibrium, the dimensions and forces given in FIG. 11b are to be considered. From this an equilibrium condition is calculated according to equation (7). Considering again the dependence of the distance variables a and b from the articulation angle εi of the mast 14 and of the position of the boom arms 1a to 1d, and further considering the reasons of strength, maximum allowable cylinder force F _max, we obtain again a limit curve for the cylinder force for _E nz (ε-ι) according to curve 1 of Fig. 5. This curve is given in tabular form as a data field for the limit value of the cylinder force and compared with a software routine corresponding to FIG. 7 with the measured values Fz _y ι.

Thus, an allowable arm configuration of the work mast 14 can be determined for all variants, which corresponds to the safety criterion according to equation (6).

In summary, the following should be noted: The invention relates to a work mast, in particular for large manipulators and concrete pumps.

The work mast 14 has a rotatable about a vertical axis 13 on a frame 11 rotary head 21, one about a horizontal bending axis A opposite the rotary head 21 by means of a drive unit 22 limited pivotable first mast arm 1 and at least one relative to an adjacent mast arm by means of an associated drive unit 23 to 25 along a push axis longitudinally displaceable and / or about a horizontal buckling axis B ₁ C ₁ D pivotable further mast arm 2.3 , 4 on. Furthermore, a preferably remotely controllable control device for the mast movement is provided by means of actuators associated with the individual drive units. As actuators are mainly control valves into consideration, over which the drive unit designed as a hydraulic cylinder 22 to 25 are controlled. At least one of the mast arms, the thrust and / or bending axes, the vertical axis 13 and / or the drive units 22 to 25, a sensor 54 is arranged for path or angle measurement. The control device has a safety routine responding to output data of the sensors. At the bottom and rod end of at least one of the drive units designed as a hydraulic cylinder 22, pressure or force sensors 42, 44 are also arranged, while the safety routine comprises an evaluation part 56 which responds to the output data of the pressure or force sensors. In order to make better use of the kinematics in the articulated boom movement, the safety routine comprises a data memory for recording an analytically or in a table form given data field of pressure or force limits depending on at least one of the mast arms associated path or angle measurements. The evaluation unit 56 has a comparator with the output data of the pressure or force sensors 42,44 or the associated displacement or angle sensors 54 or derived variables for performing a comparison with associated threshold data from the data field and for triggering a signal at bottom or Exceeding the limit data is applied.

Claims

claims

1. work mast, with a about a vertical axis (13) on a frame (11) rotatable turret (21), with at least three mast arms (1,2,3,4), each about horizontal, mutually parallel bending axes (A ₁ B ₁ C ₁ D) relative to the rotary head (21) or an adjacent mast arm by means of a respective drive unit (22 to 25) are pivotally limited, with a preferably remote-controlled control device for the mast movement with the aid of the individual drive units (22 to 25) associated actuators, with at least one sensor for path or angle measurement, the at least one of the mast arms (1, 2,3,4) of the bending axes (A ₁ B ₁ C ₁ D), the vertical axis (13) and / or the drive units (22 to 25 ), wherein the control device has a safety routine responding to output data of the at least one sensor, and wherein at the bottom and / or rod end of at least one of the drive units designed as a hydraulic cylinder pressure or force sensors (42, 44) are arranged and the safety routine comprises an output part of the pressure and force sensors responsive evaluation part (56), characterized in that the safety routine a data memory for receiving an analytically or in tabular form predetermined data field of printing or force thresholds (F _Gren:) associated with the function of at least one of the boom arms Wegoder angle measurement values (εi), and in that the evaluation unit (56) comprises a comparator with the output data of the printing o- of the force sensors (42,44) and the associated Displacement or angle sensors (54) or variables derived therefrom (F _Zyl ) for carrying out a comparison with associated limit value data (F _Gren:) from the

Data field and for triggering a signal (57) when the limit value is undershot or exceeded.

2. Work mast with a about a vertical axis (13) on a frame (11) rotatable rotary head (21) with a about a horizontal bending axis (A) relative to the rotary head (21) by means of a drive unit limited pivotable first mast arm (1), with at least one relative to each adjacent mast arm by means of an associated drive unit along a thrust axis longitudinally displaceable and / or about a horizontal bending axis (B ₁ C ₁ D) pivotable further mast arm (2,3,4), with a preferably remotely controllable control device for the mast movement with the help associated with the individual drive units actuators, with at least one sensor for displacement or angle measurement, the at least one of the mast arms, the thrust and / or bending axes, the vertical axis (13) and / or the drive units is assigned, wherein the control means a has on output data of the at least one sensor responsive safety routine, and wherein the ground and / o the rod-side end of at least one designed as a hydraulic cylinder drive units pressure or force sensors are arranged and the safety routine responsive to the output data of the pressure and force sensors evaluation unit (56), characterized in that the safety routine a data memory for receiving an analytic or in tabular form predefined data field from pressure or force limit values {F _limit ) as a function of at least one of the mast arms associated path or angle measured values (εi), and that the evaluation unit (56) has a NEN comparator with output data of the pressure or

Force sensors (42,44) and the associated displacement or angle sensors (54) or derived variables (F _cyl ) for performing a

Comparison with assigned limit value data (F _Cren! ) From the data field and for triggering a signal (57) when the limit value is _undershot or exceeded.

3. Work mast according to claim 2, characterized in that the first mast arm (1) by means of the hydraulic cylinder designed as a drive unit (22) relative to the rotary head (21) is pivotable about 90 °.

4. Work mast according to one of claims 2 or 3, characterized in that at the end of the first mast arm (1) from at least one further mast arm (2,3,4) existing mast boom about a horizontal bending axis (B ₁ CD) is pivotally articulated ,

5. Work mast according to claim 2, characterized in that the first mast arm (1) with a plurality of telescopically against each other, longitudinally displaceable mast arms (1a to 1f) is connected.

6. Work mast according to claim 5, characterized in that at the end of the last longitudinally displaceable mast arm (1f) at least one of a plurality of horizontal buckling axes (B to E) against each other pivotable mast arms (2 to 5) composite mast boom is articulated.

7. Work mast according to one of claims 1 to 6, characterized in that at least one mast arm at a distance from the bending axis (A) of the first mast arm (1) a deflection roller (80) is arranged, via which a rope (82) with a Receiving member (84) is guided for a movable load, and that on the rope (82) a pressure or

Force sensor (86) is arranged, whose output is connected to the evaluation part (56) of the safety routine.

8. Work mast according to one of claims 1 to 7, characterized in that the at least one angle sensor (54) on the bending axis (A) of the associated mast arm (1) is arranged.

9. Work mast according to one of claims 1 to 7, characterized in that the at least one displacement sensor on the associated as a hydraulic cylinder (22 to 25) formed drive unit of the mast arm (1 to 4) is arranged.

10. Work mast according to one of claims 1 to 9, characterized in that a further displacement or angle sensor on the drive unit or in the region of the vertical axis (13) of the rotary head (21) is arranged and that in the data memory of the safety routine analytically or in Table form filed from pressure or force limits {F _Gma ) is additionally correlated with the rotary head associated displacement or angle measurements.

11. Work mast according to one of claims 1 to 10, characterized in that at least one of the actuators responds to the over the safety routine when exceeding limit data triggered signal execution of a safety movement or a safety stop.

12. Work mast according to one of claims 1 to 11, characterized in that the control device comprises a responsive to the distance or angle measurement data position controller for the mast movement.

13. Work mast according to one of claims 1 to 12, characterized in that at least one of the mast arms a geodesic

Angle sensor for performing the mastarm related path or angle measurements is arranged.

14. Work mast according to claim 13, characterized in that in addition to a rotary head (21) arranged geodetic angle sensor for measuring a turret associated with the earth-fixed angle measured value is provided.

15. Work mast according to claim 13 or 14, characterized in that in addition at least one of the frame (11) arranged geodesic angle sensor for measuring at least one of the frame associated earth-fixed angle measurement value is provided.

16. Work mast according to one of claims 13 to 15, characterized in that the geodesic angle sensors are designed as responsive to the gravity of the earth inclination angle sensor.

17. Work mast according to one of claims 13 to 16, characterized in that the control device has a software routine for the conversion of earth-fixed mastarmbezogene angle measured values in bending angle (εi).

18. Work mast according to one of claims 1 to 17, characterized in that the control device comprises a responsive to the time-dependent path or angle measurements and / or on the pressure or force measurements vibration damper for the mast arms of the distributor mast.