Mobile crane support with locking device

Abstract

The invention relates to a mobile crane outrigger with a first support segment (1), a second support segment (2), and a locking device (4) for preventing movement of the second support segment (2) in the direction of travel (T) and in any relative position between the first support segment (1) and the second support segment (2). The locking device comprises a clamping element which is held in contact with a bearing surface formed between the first and second support segments by a holding device. The clamping element is mounted relative to the first and second support segments such that a movement of the second support segment in a direction away from the outrigger foot causes an increase in the force applied by the clamping element to the bearing surface, thus locking the second support segment (2) relative to the first support segment (1). The invention further relates to a mobile crane with such an outrigger.

Description

[0001] The present invention relates to a mobile crane support device in which any relative position of two support segments that can be moved relative to one another is determined by means of a locking device.

[0002] To give mobile cranes sufficient tipping stability during crane operation, their undercarriage is equipped with outriggers, usually four of which can be extended and / or pivoted transversely to the undercarriage's longitudinal axis. At the ends facing away from the undercarriage, the outriggers each have a vertically extendable outrigger cylinder which is supported on the ground by means of an outrigger plate. Typically, two outriggers are arranged at the front and rear of the undercarriage and can extend in opposite directions to each other. Deformations and load changes during crane operation cause longitudinal forces in the outriggers, which can lead to displacement of the outriggers. Typically, unintentional longitudinal movement of the outriggers is prevented by mechanical bolting. However, for design reasons, the number of possible bolting positions is limited.

[0003] Modern cranes feature a load moment limiter that essentially allows any desired outrigger position to be reached, simplifying or even enabling crane operation in difficult space conditions. However, for the reasons stated above, mechanical bolting and thus secure fixing of the outrigger beam position is not possible for all outrigger beam positions. This requires continuous monitoring of the current outrigger beam position and the inhibition of certain crane functions if an outrigger beam has left its target position for safe crane operation. DE 10 2020 212 687 proposes fixing the outrigger beam position by means of a brake rail and a brake engagement element that engages the brake rail. WO 2016 / 146267 A1 discloses the preamble of claim 1.

[0004] It is the object of the present invention to provide an improved possibility compared to previous solutions for reliably determining the position of outriggers for crane operation.

[0005] This object is achieved by the subject matter of independent patent claim 1. The subclaims and the independent patent claim 14 define preferred embodiments of the present invention and a mobile crane comprising the present invention, respectively.

[0006] The mobile crane support device according to the invention comprises a first support segment which can be fastened to the undercarriage of the mobile crane, a second support segment which can be moved within and relative to the first support segment and which has a support foot which can be moved in the vertical direction, and a locking device for preventing movement of the second support segment in the direction of travel and in any relative position between the first support segment and the second support segment.The locking device according to the invention has at least one clamping body which is held in contact with a run-up surface formed between the first and the second support segment by a holding device and is mounted relative to the first and the second support segment in such a way that a displacement movement of the second support segment in a direction away from the support foot causes an increase in the force applied by the clamping body to the run-up surface and thus causes the second support segment to be fixed relative to the first support segment.

[0007] The first support segment can be formed by a so-called support box, which occupies a fixed position on the crane undercarriage, either permanently or detachably. However, the first support segment can also be formed by a support beam that can be translationally moved or rotationally pivoted relative to the crane undercarriage or a support box. The support device according to the invention can therefore be constructed from any number of support segments that can be rotationally or translationally moved relative to one another and / or relative to the crane undercarriage, and whose translational movements can be prevented by a locking device according to the invention.

[0008] The locking device is intended to prevent unwanted movement of the second support segment relative to the first support segment and thus to the crane undercarriage. In particular, movements that could reduce the distance between the crane undercarriage and a corresponding support leg, and consequently reduce the tipping stability of the mobile crane, are to be prevented. In principle, the locking device according to the invention is suitable for preventing unwanted translational and / or rotational movements between two support segments. With regard to rotational movements, the locking device would have to be designed such that the contact surface moves on a circular path around the center of rotation of the second support segment, on which path it can contact the clamping body.To prevent translational movements, the contact surface moves in a direction parallel to the movement of the second support segment so that it can run onto the clamping body. For the sake of simplicity, reference is made below to translational movements of the second support segment, although the inventive considerations can be easily adapted to rotational movements.

[0009] According to the invention, the run-up surface interacting with the clamping body serves to reduce the space available for the clamping body between the first and second support segments when the second support segment moves, so that the clamping body is supported on the first and second support segments, in particular is brought into contact with surfaces (including the run-up surface) on the first and second support segments or on structures assigned to these support segments, and through frictional engagement prevents further movement of the second support segment relative to the first support segment. Turned again in another way, the locking device according to the invention uses the technical operating principle of self-locking. The locking device can have one or more run-up surfaces and / or clamping bodies, in particular one or more pairings of a run-up surface with a clamping body.

[0010] The contact surface can be shaped and / or oriented in any suitable manner, particularly with respect to the direction of travel of the second support segment. For example, a flat shape of the contact surface, extending particularly parallel to the direction of travel of the second support element, is conceivable, as is a concave shape, i.e., one curved or arched inward. Any suitable "angle of incidence" of the contact surface relative to the direction of travel is also possible, with the clamping forces and thus the force required to release or separate the clamping body from the contact surface increasing as the angle decreases.

[0011] According to one embodiment, the clamping body is arranged in a cavity defined by the first support segment and the second support segment. Furthermore, it is conceivable that a further surface, with which the clamping body is brought into contact next to the contact surface, is oriented parallel to the direction of travel of the second support segment and, in particular, extends in a horizontal or vertical direction.

[0012] According to a further embodiment, the clamping body is eccentrically mounted on the first or second support segment. Thus, by rotating the clamping body about its eccentric mounting, the relative position between its peripheral surface and the contact surface can be varied. To hold the clamping body in contact with the contact surface, the holding device can cause a rotational movement of the clamping body about its eccentric axis of rotation. In particular, the holding device can act on the clamping body via a lever arm to increase the resulting holding force.

[0013] According to a further embodiment, the clamping body can be supported on the first and second support segments, in particular directly on surfaces of the first and / or second support segments. However, it is also conceivable that the forces applied by the clamping body to the corresponding support segment are indirectly introduced into the corresponding support segment via intermediate structures arranged between the clamping body and the corresponding support segment.

[0014] According to a further embodiment, the clamping body has a roller-shaped, in particular cylindrical, form and contacts the contact surface, in particular the first support segment and the second support segment, via its circumferential surface. A roller-shaped, in particular cylindrical clamping body provides a good compromise between the surface pressure that occurs and the holding force or force necessary to separate the clamping body from the contact surface. In principle, any other shapes of the clamping body are conceivable, for example balls or wedges. To achieve the clamping effect, the clamping body can be brought into contact with corresponding surfaces (including the contact surface) that are formed directly on the first and second support segments, or with surfaces that are indirectly connected to the first and / or the second support segment, for example via any number of intermediate structures.

[0015] Furthermore, the holding device can have at least one spring element, in particular a prestressed spring element, which is supported on the first or second support segment. According to a further embodiment, the clamping device can have an unlocking device, which can counteract the holding device in particular and which selectively, i.e., by activating the unlocking device, separates the clamping body from the contact surface and / or keeps the clamping body spaced from the contact surface.

[0016] Any suitable device can be used to move the second support segment relative to the first support segment, for example, mechanical drives with a gear engagement. According to one embodiment, the movement of the second support segment in the direction of travel relative to the first support segment is effected by a hydraulic cylinder, in particular by a double-acting hydraulic cylinder.

[0017] In a further embodiment, the unlocking device is actuated hydraulically. This makes it possible to couple the actuation of the unlocking device to the actuation of the hydraulic cylinder by means of which the second support segment is moved in the direction of travel. In particular, it is possible for the hydraulic cylinder for the unlocking device to be actuated simultaneously or with a certain advance when the support segment's hydraulic cylinder is actuated. Thus, the clamping device is unlocked, i.e., the clamping body is separated from the contact surface, during or before the second support segment is moved.

[0018] In a further embodiment, the unlocking device is actuated both when the second support segment moves in a direction of travel pointing away from the support foot and when it moves in an opposite direction, i.e., in a direction pointing towards the support foot.

[0019] Furthermore, the support leg can be moved vertically downwards or upwards relative to the second support segment by means of a hydraulic support cylinder.

[0020] In a further embodiment, the first support segment is formed by a support box with support beams movable on both sides of the support box, each forming a second support segment.

[0021] A further aspect of the present invention relates to a mobile crane with a support device according to one of the embodiments described above.

[0022] The present invention will be explained in more detail below using a preferred embodiment and with reference to the accompanying figure. It shows: Figure 1 shows a first embodiment of the support device according to the invention; Figure 2 shows a second embodiment of the support device according to the invention.

[0023] The Figure 1shows a schematic representation of the structure of a preferred embodiment of the support device according to the invention. A first support segment 1 is formed here by a so-called support box, which in mobile cranes is usually arranged in the front and rear area of the undercarriage transversely to the longitudinal axis of the undercarriage. The support box 1 accommodates a second support segment 2 in a horizontally displaceable manner, which is referred to below as support beam. Not shown is a further support beam accommodated by the support box 1, which is arranged on the other, in the Figure 1left side of the support box 1 in an identical manner relative to the support box 1. At this point, it should be mentioned that the support beams 2 received by the support box 1 can be moved independently of one another into any desired position and can be secured there by means of the locking devices 4 assigned to them against unintentional retraction into the support box 1.

[0024] The support beam 2 has, at its end facing away from the support box 1 or the crane undercarriage, an outrigger foot 3 which can comprise an outrigger plate in contact with the ground and a piston rod of a hydraulic cylinder 13 which is articulated thereto, by means of which the outrigger foot 3 can be moved vertically downwards and upwards again in order to establish or terminate support of the mobile crane on the ground.

[0025] At the start of the support operation, the support beam 2 is extended to the right out of the support box 1 to a desired length. This is done by the double-acting hydraulic cylinder 10, which is supplied with hydraulic fluid via the hydraulic lines 12 and thus controlled. Both the piston chamber and the annular chamber of the hydraulic cylinder 10 are fluidly connected to a shuttle valve 11, which in turn is connected to the piston chamber of the release device 9 designed as a hydraulic cylinder. Both when the support beam 2 is extended and when it is retracted, the piston chamber of the release hydraulic cylinder 9 is connected via the shuttle valve 11 to the piston chamber of the support beam hydraulic cylinder 10 or to the annular chamber of the support beam hydraulic cylinder 10, and is thus pressurized in both cases.The subsequently extending piston of the unlocking hydraulic cylinder 9 acts against the preload force of the holding device 8, designed as an elastic spring, on the cylindrical clamping body 6 and separates it from the support surface 5. In this state, the support beam 2 can be extended from the support beam 1 or retracted into it as desired. It should be noted that the hydraulic actuation 11 of the locking device 4 is designed such that the unlocking hydraulic cylinder 9 acts on the clamping body 6 and separates it from the contact surface 5 before the support beam 2 is extended from the support box 1 or retracted into it.

[0026] As soon as the support beam 2 has reached its desired support position, the supply of hydraulic fluid through the hydraulic lines 12 is stopped, so that the hydraulic cylinder 10 remains in its current position. The preload force of the holding device 8 brings the clamping body 6 into contact with the contact surface 5, and the piston of the release hydraulic cylinder 9 partially displaces the hydraulic fluid remaining in its piston chamber through the shuttle valve 11 and the hydraulic supply 12 into the hydraulic circuit of the mobile crane.

[0027] To support the mobile crane, the outrigger foot 3 is extended vertically downwards by means of the hydraulic cylinder 13, so that the mobile crane subsequently rests on the ground via all support devices. Should forces occur during subsequent crane operation that would push the outrigger beam 2 back into the outrigger box 1 and thus lead to a reduction in the tipping stability of the mobile crane, such an unintentional displacement is effectively prevented by the locking device 4. The clamping body 6 resting against the run-up surface creates a self-locking effect between the outrigger beam 2 and the outrigger box 1 during such a return movement.Thus, the preload force of the holding element 8 and the static friction prevailing in the contact areas between the clamping body 6 and the run-up surface 5 formed on the support beam 2 on the one hand, and the clamping body 6 and the horizontal inner surface of the support box 1 on the other hand, prevent movement and thus also deflection of the clamping body 6 relative to the support beam 2. On the other hand, it is also not possible for the support beam 2 to move over the clamping body 6 into the support box 1 because its upper side facing away from the locking device 4 is in contact with the support box 1, which prevents deflection in the vertical direction. Since the clamping effect caused by the clamping body 6 also increases with increasing force acting on the support beam 2, unintentional insertion of the support beam 2 into the support box 1 is effectively prevented.To release the locking of the support beam 2 relative to the support box 1, the release hydraulic cylinder 9 is activated in the manner already described above as soon as the support beam 2 is to be moved by the hydraulic cylinder 10. The clamping body 6 is separated from the run-up surface 5 and kept at a distance, so that a clamping effect is prevented during the retraction of the support beam 2 into the support box 1.

[0028] The Figure 2 shows a second embodiment of the support device according to the invention. Figure 1 This second embodiment differs essentially only in the design of the locking device 4 from the embodiment shown. The design and in particular the functioning of the support box 1, the support beam 2 and the support foot 3 including the hydraulic cylinder 13 is identical to the first embodiment.

[0029] In the Figure 2 It can be seen that the clamping body 6 is mounted in a rotational axis 14 on the support box 1. The rotational axis 14 is in this case different from the Figure 2 not shown axis of symmetry of the cylindrical clamping body 6 in order to realize an eccentric rotary mounting of the clamping body 6 on the support box 1.

[0030] A lever 15 is connected to the clamping body 6 in a rotationally fixed manner, via which the pre-tensioned spring 8, which is supported on the support box 1, acts on the clamping body 6 and thus holds the circumferential surface of the clamping body 6 in contact with the lower run-up surface 5 of the support beam 2, which extends in the direction T.

[0031] When the support beam 2 is pushed out of the support box 1, the clamping body 6 slides along the run-up surface 5 or is released from it by means of a Figure 2not shown release mechanism. In case of an unintentional insertion of the support beam 2 into the support box 1, the friction between the peripheral surface of the clamping body 6 and the contact surface 5 causes a rotational movement of the clamping body 6 about its axis of rotation 14 in an anti-clockwise direction. Due to the eccentric pivot bearing of the clamping body 6, its contact pressure on the contact surface 5 is increased. As already in the first, in the Figure 1In the embodiment shown, it is not possible for the clamping body 6 to deflect relative to the support beam 2. To prevent further rotation of the clamping body 6 in the counterclockwise direction and to relieve the load on the eccentric pivot bearing 14, the clamping body 6 contacts a vertical surface of the support box 1 from a certain angle of rotation. The resulting angle of rotation is selected such that the force introduced into the support beam 2 in the vertical direction by the clamping body 6 is sufficiently large to generate sufficiently large friction on the upper side of the support beam 2 between the support box 1 and the support beam 2, which prevents further insertion of the support beam 2 into the support box 1.

[0032] To release the locking mechanism between support beam 2 and support box 1, a release device can be used, which is located in the Figure 2not shown. For example, by means of a hydraulic cylinder acting on the lever 15, the clamping body 6 can be rotated clockwise about its pivot bearing 14 in order to space the peripheral surface of the clamping body 6 from the run-up surface 5, thus ultimately enabling the support beam 2 to be inserted into the support box 1.

Claims

1. Mobile crane support device comprising - a first support segment (1) which can be fastened to the undercarriage of the mobile crane; - a second support segment (2) which is mounted such that it can travel within and relative to the first support segment (1) and which has an outrigger (3) that is movable in the vertical direction (V); - a locking device (4) for preventing a movement of the second support segment (2) in the travel direction (T) and in any relative position between the first support segment (1) and the second support segment (2); characterised in that the locking device (4) has a clamping member (6) which is held in contact with a contact surface (5) formed between the first and the second support segment (1, 2) by a holding device (8) and which is mounted relative to the first and the second support segment (1, 2) in such a way that a travel movement of the second support segment (2) in a direction pointing away from the outrigger (3) causes the force applied to the contact surface (5) by the clamping member (6) to be increased, thereby locking the second support segment (2) with respect to the first support segment (1).

2. Mobile crane support device according to claim 1, wherein the clamping member (6) is arranged in a cavity (7) surrounded by the first and second support segment (1, 2) and / or the contact surface (5) extends obliquely to the travel direction (T) of the second support segment (2).

3. Mobile crane support device according to claim 1, wherein the clamping member (6) is eccentrically mounted on the first or on the second support segment (1, 2), in particular wherein the holding device (8) acts on the clamping member (6) via a lifting arm (15).

4. Mobile crane support device according to one of claims 1 to 3, wherein the clamping member (6) is supported on the first and on the second support segment (1, 2), in particular directly supported thereon.

5. Mobile crane support device according to one of claims 1 to 4, wherein the contact surface (5) is associated with the first support segment (1) or with the second support segment (2).

6. Mobile crane support device according to one of claims 1 to 5, wherein the clamping member (6) is roll-shaped, in particular has a cylindrical shape, and its circumferential face contacts the contact surface (5), in particular the first support segment (1) and the second support segment (2).

7. Mobile crane support device according to one of claims 1 to 6, wherein the holding device (8) comprises a spring element, in particular a preloaded spring element, which is supported on the first or on the second support segment (1, 2).

8. Mobile crane support device according to one of claims 1 to 7, wherein the clamping device (4) has an unlocking device (9) which counteracts the holding device (8) and optionally separates the clamping member (6) from the contact surface (5).

9. Mobile crane support device according to one of claims 1 to 8, wherein the movement of the second support segment (2) in the travel direction (T) relative to the first support segment (1) is brought about by a hydraulic cylinder (10).

10. Mobile crane support device according to one of claims 1 to 9, wherein the unlocking device (9) has a hydraulic actuator (11) which is coupled in particular to the hydraulic controller (12) of the hydraulic cylinder (10) that brings about the movement of the second support segment (2) in the travel direction (T).

11. Mobile crane support device according to one of claims 1 to 10, wherein the unlocking device (9) is actuated both when the second support segment (2) moves in a travel direction (T) pointing away from the outrigger (3) and when it moves in the opposite direction.

12. Mobile crane support device according to one of claims 1 to 11, wherein the outrigger (3) has a hydraulic support cylinder (13).

13. Mobile crane support device according to one of claims 1 to 12, wherein the first support segment (1) is formed by a support box having support arms which can travel on both sides of the support box and which each form a second support segment (2).

14. Mobile crane having a support device according to one of claims 1 to 13.

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