Crane and method for influencing a deformation of a jib system of said crane

Abstract

A crane having at least one jib system, a sensor unit for detecting a deformation of the jib system transversely to a load plane, and to an activatable adjustment unit for influencing the deformation of the jib system transversely to the load plane.

Claims

1. A crane, said crane comprising: a jib system; a sensor unit operable to detect a deformation of the jib system transverse to a load plane; and an activatable adjusting unit configured to influence the deformation of the jib system transverse to the load plane; wherein a regulating unit and/or a monitoring unit is provided, with said regulating unit being in signal communication with the sensor unit and with the adjusting unit and configured to influence the deformation of the jib system in a regulated manner transverse to the load plane, and with said monitoring unit being in signal communication with the sensor unit and operable to monitor the deformation of the jib system transverse to the load plane, and wherein the adjusting unit has a load application actuator, which is connected to a load application unit and the jib for directly displacing deflection rollers arranged on a head region of the jib.

2. The crane system as claimed in claim 1, wherein the load application actuator is designed as a cylinder element, spindle drive, linear motor or lantern pinion.

3. The crane as claimed in claim 1, wherein the sensor unit has a first sensor element and a second sensor element corresponding thereto.

4. The crane as claimed in claim 3, wherein a direct connecting line between the first sensor element and the second sensor element is oriented in parallel with the jib longitudinal axis when the jib is in a non-deformed state.

5. The crane as claimed in claim 1, wherein the sensor unit detects external effects.

6. The crane as claimed in claim 5, wherein the sensor unit comprises an inclination transducer, an accelerometer, a wind gauge, a strain gauge, a force meter and/or a thermometer.

7. The crane as claimed in claim 1, wherein a jib anchoring unit is provided which acts transversely to the load plane and/or along a jib longitudinal axis, wherein the adjusting unit has an anchoring actuator for adapting the anchoring force.

8. The crane as claimed in claim 7, wherein the anchoring actuator is designed as a cable winch, a cylinder element, a spindle drive, a force-variable or a length-variable anchoring support and/or as an articulation point of the anchoring arrangement which can be displaced longitudinally of the jib longitudinal axis.

9. The crane system as claimed in claim 1, wherein the load application actuator is arranged in the head region of the jib.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic view of a crane having a lattice mast jib and a geometric actuator;

(2) FIG. 2 shows a schematic view of the jib system shown in FIG. 1 to illustrate the deformation transverse to the load plane;

(3) FIG. 3 shows a view of the jib system corresponding to FIG. 2 to illustrate the mode of operation of the geometry actuator;

(4) FIG. 4 shows a flow diagram to illustrate method steps for a method of operating a crane;

(5) FIG. 5 shows an enlarged view of a section of a jib of a crane according to a further embodiment;

(6) FIG. 6 shows an enlarged sectional view as per sectional line VI-VI in FIG. 5;

(7) FIG. 7 shows a view of a jib of a crane corresponding to FIG. 2 according to a further embodiment having lateral jib anchoring units and anchoring actuators;

(8) FIG. 8 shows a view of a jib of a crane corresponding to FIG. 2 according to a further embodiment having a load application actuator;

(9) FIG. 9 shows a front view of the jib corresponding to FIG. 8;

(10) FIG. 10 shows a schematic side view of the crane shown in FIG. 1 having further adjusting units; and

(11) FIG. 11 shows an enlarged detailed view shown in FIG. 1 to illustrate a further adjusting unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) A crane 1 which is illustrated in FIGS. 1 to 3 has a mobile lower carriage 2 and a superstructure 4 which is arranged on the lower carriage 2 in such a manner as to be able to rotate by means of a rotary connection 3. The lower carriage 2 has crawler tracks 5. The crane 1 is a crawler crane. The crane 1 can also be designed as a mobile crane suitable for use in road traffic, i.e. having rubber tyres. It is also feasible for the lower carriage 2 to be designed statically, i.e. immovably. It is also feasible for the rotary connection 3 not to be provided.

(13) A jib 7 is articulated to the crane 1, in particular to the superstructure 4, in such a manner as to be pivotable about a jib luffing axis 6. The jib luffing axis, or luffing axis for short, is arranged in parallel with a ground surface 8, on which the crane 1 is positioned. In particular, the jib luffing axis 6 is oriented horizontally. The luffing plane is oriented perpendicularly to the luffing axis, i.e. to the plane of the drawing as shown in FIG. 1. In the event that the luffing axis 6 is oriented horizontally, the luffing plane is identical to the load plane. The luffing plane includes the jib longitudinal axis 11. The jib 7 is designed as a lattice mast jib having a plurality of, in particular four, chord tubes 9 and a reinforcing structure 10 which has diagonal bars and unstrained members. The jib 7 has, along the jib longitudinal axis 11, a first jib portion 12 and a second jib portion 13 which is connected thereto and can be displaced relative to the first jib portion 12. The two jib portions 12, 13 are substantially identical. The two jib portions 12, 13 are each arranged concentrically to the jib longitudinal axis 11 and one behind the other along the jib longitudinal axis 11. The first jib portion 12 is connected directly to the crane 1, in particular to the superstructure 4, in such a manner as to be able to pivot about the jib luffing axis 6. The region of the first jib portion 12 adjacent to the jib luffing axis 6 forms the so-called foot region of the jib 7. Opposite the foot region, the jib 7 has a head region. The head region forms an upper end of the jib 7. According to the exemplified embodiment shown, the head region is arranged on an upper end of the second jib portion 13. The first jib portion 12 and the second jib portion 13 are connected to one another by means of a joint element 14 so as to be able to pivot about a joint axis 15. The first jib portion 12 and the second jib portion 13 are connected to one another in an articulated manner. The joint axis 15 is oriented perpendicularly to the plane of the drawing shown in FIG. 1. The joint axis 15 is aligned centrally on the jib 7 in relation to the width of the jib 7. The joint axis 15 intersects the jib longitudinal axis 11. It is also feasible for the joint element 14 to be arranged eccentrically. In this case, the jib longitudinal axis 11 and the joint axis 15 are arranged in skew fashion. In particular, it is feasible for the joint element 14 to be arranged directly between two chord tubes of two adjacent jib portions. In particular, it is feasible to have a plurality of joint elements 14 which are arranged e.g. on two adjacent chord tubes of the jib portions.

(14) Furthermore, the first jib portion 12 and the second jib portion 13 are connected to one another, in particular directly, by means of at least one geometry actuator 18. The at least one geometry actuator 18 serves to directly modify the geometry of the jib 7, in particular for relative positioning of the two jib portions 12, 13 with respect to one another. According to the exemplified embodiment shown, four geometry actuators 18 are provided. The geometry actuators 18 are arranged in extension of the respective chord tubes 9. Particularly when one or a plurality of joint elements are arranged directly on the chord tube 9, it is feasible to attach a geometry actuator to the chord tube which is arranged oppositely in each case in relation to the jib longitudinal axis. In particular, it is feasible for the geometry actuators 18 and joint elements 14 to be arranged in each case in a mirror-symmetrical manner with respect to the luffing plane. According to the exemplified embodiment shown, the geometry actuator 18 is designed as a force-variable and/or length-variable element. According to the exemplified embodiment shown, the geometry actuator 18 is a hydraulic cylinder element, wherein the cylinder housing is pivotably connected on a chord tube 9 of the first jib portion 12 arranged at the bottom. A push rod of the hydraulic cylinder element is pivotably connected to a chord tube 9 of the second jib portion 13 arranged at the top. The line of action of the geometry actuator 18 is arranged in parallel with and spaced apart from the jib longitudinal axis 11. In the non-deformed state of the jib 7 as shown in FIG. 1, the line of action of the geometry actuator 18 is in parallel with the respective chord tubes 9 of the jib portions 12, 13. The geometry actuators 18 form an adjusting unit 19. It is also feasible for the adjusting unit 19 to comprise precisely one geometry actuator 18 or more than two geometry actuators 18. The geometry actuators 18 can be actuated, i.e. are activatable. The adjusting unit 19 is activatable. The geometry actuators 18 are arranged outside the luffing plane and outside the load plane. The joint axis 15 is included in the luffing plane and in the load plane. The joint axis 15 can also be arranged outside the luffing plane and outside the load plane.

(15) The head region of the jib 7 is provided with a load application unit 16. The load application unit 16 comprises a plurality of deflection rollers 17 and at least one lifting cable, not illustrated, and a hook, not illustrated, which is fastened thereto for lifting a load. A load being lifted causes a loading to be introduced into the jib 7.

(16) A first sensor unit 20 for detecting a deformation of the jib 7 transverse to the load plane of the crane 1 is provided directly on the jib 7. The first sensor unit 20 comprises a first sensor element 21 and a second sensor element 22 corresponding to the first sensor element 21. The first sensor element 21 is designed as a source element, in particular as a light source. The second sensor element 22 is designed as a target element, in particular as a light detector. The second sensor element 22 serves to receive an item of information from the first sensor element 21. The sensor elements 21, 22 are attached to the jib 7 such that a source direction 23 and a target direction 24 are oriented with respect to each other in parallel and in particular in parallel with the jib longitudinal axis 11. A direct connecting line between the sensor elements 21, 22 is in parallel with the jib longitudinal axis 11. In this state, signals can be transmitted from the source element to the target element without interference.

(17) It is also feasible for the first sensor element 21 to be a combined source/target element, i.e. a light source having an integrated light detector. In this case, the second sensor element can be designed as a light reflector. In this embodiment, the effect is identical because signals can be transmitted without interference between the two sensor elements 21, 22 only when the direct connecting line between the two sensor elements is oriented in parallel with the jib longitudinal axis 11. The sensor elements 21, 22 thus render it possible in particular to detect a deformation of the jib 7.

(18) It is also possible to swap the arrangement of the first sensor element 21 with that of the second sensor element 22.

(19) The first sensor unit 20 and the adjusting unit 19 are in signal communication with a central regulating unit 25 which can be integrated in a crane controller 26. Signals can be communicated via cables or wirelessly.

(20) Furthermore, a second sensor unit 27 for detecting external effects is provided. According to the exemplified embodiment shown, an inclination sensor 28, an acceleration sensor 29 and a wind gauge 30 are combined in the second sensor unit 27. It is feasible to additionally integrate a thermometer into the second sensor unit 27. It is essential that the second sensor unit 27 measures any possibly occurring external loadings. The second sensor unit 27 is in signal communication with the regulating unit 25.

(21) Furthermore, the crane 1 has a monitoring unit 31 which enables a crane operator to monitor the operation of the crane 1 and in particular the deformation of the jib 7 transverse to the load plane. According to the exemplified embodiment shown, the monitoring unit 31 has two cameras 32 which are attached to the jib 7 such that it is possible to monitor the jib 7 in each case starting from the foot region and from the head region. This enables a crane driver or a crane operator to see regions of the crane 1 which are not visible from the crane driver's work station. This provides the crane operator with an improved monitoring option.

(22) For this purpose, the monitoring unit 31 has in particular a display unit, in particular in the form of a monitor, not illustrated, which is arranged in the region of the crane driver's work station.

(23) The mode of operation of the geometry actuator 18 is illustrated in FIG. 3. A deformation of the jib system caused as a result of the load F is counteracted by means of the geometry actuators 18 by effecting a rotation of the upper jib portion 13 anticlockwise about the joint axis 15 of the joint element 14. The geometry actuator 18 illustrated on the right-hand side in FIG. 3 is extended with respect to a neutral position illustrated in FIG. 2 and/or the geometry actuator 18 illustrated on the left-hand side in FIG. 3 is retracted with respect to a neutral position illustrated in FIG. 2. The jib system is rotated with respect to the load plane, in particular until the load F is arranged on the jib longitudinal axis 11.

(24) A method of operating the crane 1 in FIG. 1 will be explained in greater detail hereinafter with reference to FIGS. 1 to 4. The non-deformed state of the jib 7 represents the starting situation. This state is an ideal state 7 of the crane. In this state 33, the jib 7, i.e. the jib longitudinal axis 11, is linear. A loading situation of the crane 1 and in particular of the jib 7 gives rise to a deformation state 34 which deviates from the state 33. The state 33 is illustrated in FIG. 2 by a continuous line. The deformation state 34 is illustrated in FIG. 2 by a broken line. In the deformation state 34, signals from the first sensor unit 20 and the second sensor unit 27 are detected. The first sensor unit 20 provides information relating to the deformation of the jib 7 transverse to the load plane. The second sensor unit 27 provides information relating to an inclination angle of the crane 1 with respect to the horizontal, relating to a wind speed and relating to a circular acceleration of the superstructure 4 with respect to the lower carriage 2. The inclination sensor 28 can be arranged on the superstructure 4, the rotary connection 3 and/or the lower carriage 2. In particular, it is feasible for more than one inclination sensor 28 to be provided. In particular, the inclination sensor 28 can be arranged on a jib foot, i.e. in particular in the region of the jib luffing axis 6.

(25) In particular, the acceleration sensor 29 is arranged on the superstructure 4 in order to detect the circular acceleration of the superstructure. It is feasible to arrange a plurality of acceleration sensors 29 on the superstructure 4, in particular on the jib head.

(26) The wind gauge 30 is arranged on the jib head in order to detect the wind speed prevailing at that location.

(27) This information and measurement values are communicated to the regulating unit 25. In a regulating/controlling step, control signals are generated by the regulating unit 25 for the adjusting unit 19 and are communicated thereto. The control signals are generated such that the deformation of the jib 7 remains as small as possible and in particular ideally disappears, i.e. is zero.

(28) According to the exemplified embodiment shown, in the case of the deformed jib 7 an external load F acts eccentrically with respect to the jib longitudinal axis 11. A deformation of the jib 7′ can also follow from a geometric imperfection or external loads. The deformation causes in particular the upper second jib portion 13 to tilt with respect to the lower first jib portion 12 about the joint axis 15. In addition, it is feasible that a deformation of the jib portions 12, 13 themselves occurs. In order to directly counteract the deformation, the control signals which have been generated during the regulating/controlling step 35 bring about an expansion, i.e. a lengthening, of the geometry actuators 18 illustrated on the right-hand side in FIG. 3, and bring about a contraction, i.e. a shortening, of the geometry actuators 18 illustrated on the left-hand side in FIG. 3. As a result, the second jib portion 13 is displaced about the joint axis 15 anticlockwise as shown in FIG. 3.

(29) The jib 7 is displaced from the deformed state back to the starting state. Activation of the geometry actuators 18 brings about an active reduction in the deformation of the jib 7 transverse to the load plane. The active reduction is effected by means of the activatable adjusting unit 19. The adjusting unit 19 is activated via the regulating unit 25. It is also feasible for e.g. a crane operator to effect a manual activation of the adjusting unit 19. The reduction in the deformation of the jib 7 is illustrated in FIG. 4 by the method step 36. As an alternative to the regulating/controlling step 35, a regulating/controlling step 35′ can be performed which will be explained with reference to a further embodiment. Particularly when a regulated deformation reduction is provided by means of the regulating unit 25, measurement results from the sensor units 20, 27 are constantly fed back, i.e. there is continuous monitoring of internal and external loads. This means that the method steps 34, 35 and 36 can be performed repeatedly one after the other.

(30) The actual state of the crane 1 and in particular of the jib 7 is continuously checked in a checking step 37. If the check indicates that the actual deformation is within a specifiable, variably settable tolerance range, an increased load-bearing capacity of the crane 1 can be enabled for the operation. In this state 38, the crane 1 has an increased load-bearing capacity and thus increased functionality. If the check indicates that the jib deformation is outside the tolerance range, a standard load-bearing capacity is taken as a basis in order to operate the crane 1. In this state 39, the crane 1 corresponds to a crane which is known from the prior art and does not have an activated adjusting unit, as illustrated in FIG. 2. The increased load-bearing capacity is not enabled.

(31) FIGS. 5 and 6 show a further embodiment of a jib 7 for a crane 1. Components which correspond to those already explained above with reference to FIGS. 1 to 4 are designated by the same reference numerals and are not discussed again in detail.

(32) At least portions of the geometry actuators 40 are arranged in chord tubes 9 of adjacent jib portions 12, 13. According to the exemplified embodiment shown, the geometry actuator 18 is designed as a hydraulic cylinder element, wherein the cylinder tube is held in a stationary manner in one of the chord tubes. As shown in FIG. 6, the cylinder tube is held in the chord tube 9 illustrated on the left-hand side. The push rod of the cylinder element is held with a free end in a dedicated receptacle 41 in a stationary manner in the chord tube 9 of the second jib portion 13 illustrated on the right-hand side of FIG. 6. According to the exemplified embodiment shown, the push rod has a spherical head-shaped ending. Accordingly, the receptacle 41 is formed with a recess corresponding to the spherical head-shaped ending. The push rod is fixed in the receptacle 41 in relation to a longitudinal displacement along the chord tubes 9. The push rod is arranged in an articulated manner in the receptacle 41. A change in the length of hydraulic cylinder element ensures a direct change in the geometry of the jib 7.

(33) In the case of the lattice mast jib 7, it is feasible to effect a deformation without a joint, i.e. without an articulated arrangement of the push rod in the receptacle 41 in that a multiplicity of geometry actuators 40 designed as short stroke actuators are provided. Each individual short stroke actuator produces comparatively small deformations which are within the material limits. The articulated arrangement is advantageous for comparatively large displacement paths. In addition or as an alternative, other construction principles can be used, such as a tube connection which does not act as a frame corner.

(34) FIG. 7 shows a further embodiment of an adjusting unit for a crane. Components which correspond to those already explained above with reference to FIGS. 1 to 6 are designated by the same reference numerals and will not be discussed again in detail.

(35) The jib 42 has two lateral anchoring units 43. The anchoring units 43 serve to anchor the jib 42 transversely to the load plane with an anchoring force which acts in particular as a tractive force along an anchoring element of a lateral jib anchoring unit 43. The lateral jib anchoring units 43 are arranged axially symmetrically with respect to the jib longitudinal axis 11. Such jib anchoring units 43 are known per se from DE 20 2008 006 167 U1, to which reference is made in relation to details of the lateral jib anchoring units 43.

(36) The jib anchoring units 43 have anchoring elements 44 which are each articulated in the head region and in the foot region of the jib 42. The anchoring elements 44 are each guided between the head region and the foot region of the jib 42 via an anchoring support 45. The jib 42 is a telescopic jib.

(37) The adjusting unit 19 has two anchoring actuators 46 which are provided for increasing the anchoring force. The anchoring actuators 46 are designed as cable winches which are arranged fixedly on the jib 42 and in particular on the largest telescopic tube. The cable 48 of the cable winch is guided to the head region of the jib 42 via a deflection roller 47 which is fastened in particular to the anchoring support 45.

(38) As a result of an external loading F and/or as a result of disruptive influences, the jib 42 can deform and have a non-linear jib longitudinal axis 11′. The deformed state of the jib 42 is illustrated in FIG. 7 by a broken line. In this state, signals can no longer be transmitted between the sensor elements 21 and 22′ of the first sensor unit 20 without interference. By reason of this, the regulating unit 25 causes a control signal for the adjusting unit 19, in particular for the anchoring actuator 46 in the form of the cable winch, as illustrated on the left-hand side of FIG. 7. The cable winch is driven, anticlockwise as shown in FIG. 7, such that the cable 48 is rolled up onto the cable winch. As a result, the tractive force in the cable 48 which is guided in parallel with the anchoring element 44 is increased. The jib 42 is pulled back in the head region to the ideal position, to the left as shown in FIG. 7. This means that the regulating unit 25 acts upon the anchoring actuators 46 such that the deformation of the jib transverse to the load plane is optimised with respect to the effective loads and preforms. This method step is designated in FIG. 4 by the reference numeral 35′.

(39) FIGS. 8 and 9 show a further embodiment of an adjusting unit of a crane. Components which correspond to those already explained above with reference to FIGS. 1 to 7 are designated by the same reference numerals and will not be discussed again in detail.

(40) The substantial difference with respect to the foregoing embodiments is that the adjusting unit 19 has a load application actuator 50 which is connected to the load application unit 16 and the jib 49. This renders it possible for the load application unit 16, in particular the deflection rollers 17 arranged on the head region of the jib 49, to be displaceable relative to the jib 49, in particular transversely to the load plane. For this purpose, the load application actuator 50 which is designed as a force-variable and/or length-variable element is fixedly fastened with the jib 49, in particular in a dedicated holder 51, to the head region of the jib 49. The load application unit 16 is displaceable in a manner guided along a guide system 52 transversely to the load plane on the jib 49. According to the exemplified embodiment shown, the guide system 52 has rails, along which the load application unit 16 can be displaced in a manner guided on rollers. The load application actuator 50 serves to directly displace the load application location on the jib 49. According to the exemplified embodiment shown, the load application actuator 50 is designed as a hydraulic cylinder element.

(41) During a deformation of the jib 49, the load application actuator 50 and the holder 51 are jointly displaced. In order to prevent the load application unit 16 from also being displaced eccentrically, the load application actuator 50 can be activated by being extended such that the load application unit 16 is displaced back in the direction of the ideal position. In the case of this exemplified embodiment, a deformation of the jib 49 itself is knowingly tolerated as long as the load application location is in a specified tolerance range.

(42) FIG. 10 shows a side view of the crane 1 shown in FIG. 1. It is apparent therefrom that a further adjusting unit 19a is attached directly between the superstructure 4 and the jib 7. By means of the adjusting unit 19a it is possible to change the inclination angle of the luffing axis 6 with respect to the horizontal. In particular, the adjusting unit 19a acts upon the foot of the jib 7. The adjusting unit 19a comprises at least one, in particular two, eccentric bolts, in particular two eccentric bolts are thus provided along the luffing axis 6 on the foot bearings of the jib 7 in order to connect it to the superstructure 4. The eccentric bolts have a cross-sectional area with respect to the luffing axis 6 which is eccentric in relation to the luffing axis 6. By rotating the eccentric bolt about the luffing axis 6, the inclination of the luffing axis with respect to the horizontal can be influenced. As a result, it is possible to influence an inclination of the jib 7 transverse to the load plane. Rotation of the eccentric bolt results in an oblique position, i.e. an inclination, of the jib foot transverse to the load plane. In particular, it is possible, e.g. by rotating two eccentric bolts in opposite directions, to achieve a horizontal alignment of the luffing axis when the superstructure 4 is arranged in an inclined manner.

(43) FIG. 11 shows an enlarged detailed view of the crane shown in FIG. 1. FIG. 11 illustrates a further adjusting unit 19b which is arranged directly between the lower carriage 2 and the superstructure 4. The lower carriage 2 and superstructure 4 are connected directly to one another by means of the adjusting unit 19b. The adjusting unit 19b is arranged independently of the rotary connection 3 between the superstructure 4 and lower carriage 2. The adjusting unit 19b permits a relative displacement between the superstructure 4 and lower carriage 2.

(44) In addition or as an alternative, a further adjusting unit 19c, which is indicated in FIG. 11 by a broken line, can be integrated in the rotary connection 3 in order to permit a relative displacement, in particular influencing of the inclination of the jib longitudinal axis 11 with respect to the ground surface 8.

(45) FIG. 11 illustrates a floor support unit in a purely schematic manner. The floor support unit comprises a substantially horizontal support carrier 54 and a substantially vertically arranged support cylinder 55. A plurality of floor support units can be arranged on the crane. The floor support units are connected in particular to the lower carriage 2 and/or to the superstructure 4. According to the exemplified embodiment shown, a further adjusting unit 19d is provided on the floor support unit. According to the exemplified embodiment shown, the further adjusting unit 19d is attached laterally to the support cylinder 55. By means of this adjusting unit 19d it is possible to adapt an inclination of the crane 1, in particular of the lower carriage 2 with respect to the floor 8, such that the load plane is vertically oriented. This means that the luffing axis 6 is horizontally oriented.