Mobile crane outriggers with fixing devices

Abstract

To reliably define the position of a support member for crane operation in a support device of a mobile crane.SOLUTION: A support device comprises: a first support segment 1; a second support segment 2; and a fixing device 4 for preventing a movement of the second support segment 2 in a movement direction T in any relative position between the first support segment 1 and the second support segment 2, which has a clamping body 6. The clamping body 6 is held by a holding device 8 against a ramp 5 formed between the first support segment 1 and the second support segment 2 and is attached to the first support segment 1 and the second support segment 2 in such a way that a repositioning movement of the second support segment 2 in a direction away from a support leg 3 causes an increase in the force exerted by the clamping body 6 on the ramp 5, thereby fixing the second support segment 2 relative to the first support segment 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a support device for a mobile crane, in which any relative position between two support segments that can move relative to each other is defined by a fixing device. [Background technology]

[0002] To provide mobile cranes with sufficient tilt stability during crane operation, their chassis typically include outriggers, each of which includes four support members that can be extended transversely to the chassis' longitudinal axis and / or pivoted. The ends of the support members facing away from the chassis each include a support cylinder. The support cylinders can be extended vertically and are supported on the ground by support disks. Two support members, each of which can be extended in opposite directions, are typically located at the front and rear of the chassis. Deformations and load changes during crane operation can induce longitudinal forces within the support members, which can cause them to shift. Unintentional longitudinal movement of the support members is typically prevented by mechanically bolting them. However, for structural reasons, the number of possible bolting positions is limited.

[0003] Modern crane designs are equipped with load torque limiters, which, in principle, allow the support member to be moved to any position, thus simplifying or even enabling crane operation in difficult spaces that would otherwise be possible only with the use of a load torque limiter. However, for the reasons mentioned above, it is not possible to mechanically bolt the support member at every position, and therefore it is not possible to reliably determine the position of the support member. Therefore, to operate the crane safely, the current position of the support member must be continuously monitored, and certain crane functions must be disabled if the support member leaves its target position. DE102020212687 proposes determining the position of the support member using a brake rail and a brake engaging element that engages with the brake rail. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] DE102020212687 Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide an improved method compared to conventional solutions for reliably defining the position of a support member for crane operations. [Means for solving the problem]

[0006] This object is achieved by the subject matter of independent patent claim 1. The dependent claims define preferred embodiments of the invention, and equivalent patent claim 14 defines a mobile crane comprising the invention.

[0007] A support device for a mobile crane according to the present invention comprises a first support segment that can be fastened to the chassis of the mobile crane, a second support segment that is movable within the first support segment relative to the first support segment and has a support leg that can move vertically, and a locking device that prevents movement of the second support segment in the direction of movement at any relative position between the first and second support segments. The locking device according to the present invention comprises at least one clamping body that is held by a holding device in abutment against a slope formed between the first and second support segments and is attached to the first and second support segments such that a repositioning movement of the second support segment away from the support leg causes an increase in the force applied by the clamping body to the slope, thereby locking the second support segment relative to the first support segment.

[0008] The first support segment can in this case be formed by a so-called support box which has a permanently or removably fixed position on the crane chassis. However, the first support segment can equally be formed by a support member which is translationally movable or rotationally pivotable relative to the crane chassis and / or the support box. The support device according to the invention can therefore be built up from any number of support segments which can be rotationally or translationally movable relative to one another and / or the crane chassis, the translational repositioning movements of which can be prevented by the fixing device according to the invention.

[0009] The locking device prevents unintentional repositioning movements of the second support segment relative to the first support segment, and thus relative to the crane chassis. Repositioning movements that could lead to a reduction in the distance between the crane chassis and the corresponding support leg and a consequent reduction in the tilting stability of the mobile crane should be prevented. The locking device according to the invention is, in principle, suitable for preventing unintentional translational and / or rotational repositioning movements between two support segments. For rotational repositioning movements, the locking device must be embodied so that the ramp moves on a circular path around the center of rotation of the second support segment, on which path it can extend onto the clamping body. To prevent translational repositioning movements, the ramp moves in a direction parallel to the movement of the second support segment, thereby allowing it to extend onto the clamping body. For simplicity's sake, the following will refer to translational repositioning movements of the second support segment, where the discussion according to the invention can be easily adapted to rotational repositioning movements.

[0010] According to the invention, the ramps cooperating with the clamping bodies serve to reduce the space available between the first and second support segments when the second support segment moves, so that the clamping bodies can be moved into contact with the surfaces (including the ramps) supported on the first and second support segments and / or on structures assigned to these support segments, and also prevent further movement of the second support segment relative to the first support segment by frictional engagement. In other words, the fixing device according to the invention uses a self-locking technical operating principle, where the fixing device can comprise one or more ramps and / or clamping bodies, in particular one or more pairs of ramps and clamping bodies.

[0011] In that case, the ramp can be shaped and / or aligned in any suitable way, in particular with respect to the direction of movement of the second support segment. Thus, for example, it is conceivable for the ramp to have a planar shape, in particular extending parallel to the direction of movement of the second support segment, or also a concave shape, i.e., an inwardly curved or inwardly arched shape. Any suitable "pitch" of the ramp relative to the direction of movement is also possible, where the clamping force, and therefore the force required to release and / or separate the clamping body from the ramp, increases with decreasing angle.

[0012] According to one embodiment, the clamping body is arranged in a hollow space defined by the first and second support segments, and furthermore, it is conceivable that the other surface that moves the clamping body to abut laterally against the ramp is aligned parallel to the direction of movement of the second support segment and in particular extends horizontally or vertically.

[0013] According to another embodiment, the clamping body is eccentrically mounted on the first or second support segment. The relative position between the ramp and the circumferential surface of the clamping body can thus be changed by rotating the clamping body about its eccentric mount. To hold the clamping body against the ramp, the clamping body can be rotated about its eccentric axis of rotation by a holding device, which can act on the clamping body via a lever arm, in particular, to increase the resulting holding force.

[0014] According to other embodiments, the clamping bodies can be supported on the first and second support segments, in particular directly on the surfaces of the first and / or second support segments, but it is equally conceivable that the force exerted by the clamping bodies on the corresponding support segments is introduced indirectly to the corresponding support segments via intermediate structures arranged between the clamping bodies and the corresponding support segments.

[0015] According to another embodiment, the clamping body is roller-shaped, in particular cylindrical, and contacts the ramps, in particular the first and second support segments, with its circumferential surface. A roller-shaped, in particular cylindrical, clamping body provides a good compromise between the resulting surface pressure and the holding force and / or the force required to separate the clamping body from the ramps. In principle, any other shape of the clamping body is also conceivable, for example spherical or wedge-shaped. To achieve the clamping effect, the clamping body can be moved to abut against corresponding surfaces (including ramps) formed directly on the first and second support segments or against surfaces indirectly connected to the first and / or second support segments, for example via any number of intermediate structures.

[0016] The holding device may comprise at least one spring element, in particular a biasing spring element, supported on the first support segment or the second support segment. According to another embodiment, the fixing device may comprise an unlocking device, in particular capable of acting against the holding device and selectively, i.e. by activating the unlocking device, separating the clamp body from the ramp and / or holding the clamp body at a distance from the ramp.

[0017] Any suitable device can be used to move the second support segment relative to the first support segment, for example a mechanical drive including gear meshing. According to one embodiment, the second support segment is moved in the direction of movement relative to the first support segment by a hydraulic cylinder, in particular a double-acting hydraulic cylinder.

[0018] In another embodiment, the unlocking device is hydraulically actuated. In this way, it is possible to link the actuation of the unlocking device to the actuation of the hydraulic cylinder that moves the second support segment in the direction of movement. In particular, therefore, the hydraulic cylinder for the unlocking device can be actuated simultaneously with or somewhat prior to the actuation of the support segment hydraulic cylinder. In this way, the locking device is unlocked, i.e., the clamping body is separated from the ramp when or before the second support segment is moved.

[0019] In another embodiment, the unlocking device is activated both when the second support segment moves in a direction of movement away from the support leg and when it moves in the opposite direction, i.e., towards the support leg.

[0020] The support leg may be moved vertically downward or upward relative to the second support segment by a hydraulic support cylinder.

[0021] In another embodiment, the first support segment is formed by a support box with support members movable on either side of the support box, each of which forms a second support segment.

[0022] Another aspect of the invention relates to a mobile crane comprising a support device according to any one of the above-mentioned embodiments.

[0023] The present invention will be described in more detail below based on preferred embodiments and with reference to the accompanying drawings, in which: The present invention may include any of the features described herein, both individually and in any suitable combination. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a diagram of a first embodiment of a support device according to the invention; [Figure 2] 2A and 2B are views of a second embodiment of a support device according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a schematic diagram of the structure of a preferred embodiment of a support device according to the invention. The first support segment 1 is formed in this case by a so-called support box. In a mobile crane, the support box is usually arranged in the front and rear regions of the chassis transversely to the longitudinal axis of the chassis. The support box 1 accommodates a second support segment 2, hereinafter referred to as a support member, so that it can be moved horizontally. Another support member (not shown) accommodated by the support box 1 is accommodated on the other side of the support box 1 (the left-hand side in FIG. 1 ) so that it can be moved relative to the support box 1 in the same way. In this regard, it may be noted that the support members 2 accommodated by the support box 1 can be moved independently of one another to any position, where they can be protected from unintentional pulling into the support box 1 by the fixing devices 4 assigned to them.

[0026] The end of the support member 2 facing away from the support box 1 and / or the crane chassis is provided with a support leg 3 which may be provided with a support disk for contacting the ground and with the piston rod of a hydraulic cylinder 13 connected to it by a joint and which can move the support leg 3 vertically downwards and upwards again, respectively, to start or stop supporting the mobile crane on the ground.

[0027] At the start of the supporting process, the support member 2 is extended rightward out of the support box 1 to the desired length. For this purpose, a double-acting hydraulic cylinder 10 is used, which is supplied with hydraulic fluid and thereby actuated by a hydraulic line 12. 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 an unlocking device 9, embodied as a hydraulic cylinder. Both during extension and retraction of the support member 2, the piston chamber of the unlocking hydraulic cylinder 9 is connected via the valve 11 to the piston chamber of the support member hydraulic cylinder 10 and / or the annular chamber of the support member hydraulic cylinder 10 and is therefore pressurized in both cases. The resulting extending piston of the unlocking hydraulic cylinder 9 acts against the biasing force of the holding device 8, embodied as an elastic spring, on the roller-type clamping body 6, moving it away from the ramp 5. In this state, the support member 2 can be extended out from the support box 1 or retracted back into it as desired. It may be noted that the fixing device 4 is hydraulically actuated 11 such that the unlocking hydraulic cylinder 9 acts on the clamping body 6 and separates it from the ramp 5 before the support member 2 is extended out from and / or retracted back into the support box 1.

[0028] As soon as the support member 2 reaches its desired supporting position, the supply of hydraulic fluid through the hydraulic line 12 is cut off, thereby immobilizing the hydraulic cylinder 10 in its current position. The biasing force of the holding device 8 moves the clamping body 6 against the ramp 5, whereupon the hydraulic fluid remaining in the piston chamber of the unlocking hydraulic cylinder 9 is partially transferred by the piston of the unlocking hydraulic cylinder 9 back into the hydraulic circuit of the mobile crane through the shuttle valve 11 and the hydraulic supply 12.

[0029] The support legs 3 are extended vertically downwards by hydraulic cylinders 13 to support the mobile crane, which is then supported on the ground by all of the support devices. If, during subsequent crane movements, forces arise which would retract the support member 2 into the support box 1 and thus reduce the tilting stability of the mobile crane, such unintentional displacement is effectively prevented by the fixing devices 4, since during such return movement the clamping bodies 6 abutting the ramps 5 cause the support member 2 and the support box 1 to self-lock. The clamping bodies 6 are thus prevented from moving relative to the support member 2 and from yielding relative to the support member 2 by the biasing force of the holding devices 8 and by the static friction present in the contact area between the clamping bodies 6 and the ramps 5 (which are formed on the support member 2) on the one hand, and the static friction present in the contact area between the clamping bodies 6 and the horizontal inner surface of the support box 1 on the other hand. Conversely, the support member 2 cannot be retracted past the clamping body 6 into the support box 1, since with its upper side facing away from the fixing device 4 it abuts against the support box 1, thereby preventing vertical yielding. As the force acting on the support member 2 increases, the clamping effect caused by the clamping body 6 likewise increases, so that unintentional retraction of the support member 2 into the support box 1 is effectively prevented. To again release the support member 2 fixed to the support box 1, the unlocking hydraulic cylinder 9 is activated in the manner already described above as soon as the support member 2 has been moved by the hydraulic cylinder 10. The clamping body 6 is kept separated at a distance from the ramp 5 while the support member 2 is being retracted into the support box 1, so that the clamping effect is prevented.

[0030] Figure 2 shows a second embodiment of the support device according to the invention, which differs from the embodiment shown in Figure 1 essentially only in the way in which the fixing device 4 is embodied. This embodiment, in particular the functionality of the support box 1, the support member 2, the hydraulic cylinder 13 and the support leg 3, is identical to the first embodiment.

[0031] FIG. 2 shows that the clamping body 6 is rotationally mounted on the support box 1 at a rotation axis 14, which is spaced apart from the axis of symmetry of the roller-type clamping body 6 (not shown in FIG. 2) in order to rotationally mount the clamping body 6 eccentrically on the support box 1.

[0032] A lever 15 is non-rotatably connected to the clamping body 6, through which a biasing spring 8 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 inclined portion 5 of the support member 2 extending in the direction T.

[0033] When the support member 2 is extended out of the support box 1, the clamping body 6 slides along the inclined portion 5 or is held at a certain distance from it by an unlocking mechanism (not shown in FIG. 2 ). If the support member 2 is unintentionally retracted into the support box 1, the friction existing between the circumferential surface of the clamping body 6 and the inclined portion 5 causes the clamping body 6 to rotate counterclockwise about its rotation axis 14, where the rotational mounting of the clamping body 6 eccentrically increases its contact pressure on the inclined portion 5. As already shown in the first embodiment of FIG. 1 , the clamping body 6 cannot yield to the support member 2. To prevent the clamping body 6 from rotating further counterclockwise and relieve the load on the eccentric rotary mount 14, the clamping body 6 comes into contact with the vertical surface of the support box 1 at a certain rotation angle. The rotation angle established in this case is selected so that the force introduced by the clamping body 6 into the support member 2 in the vertical direction is large enough to create a sufficiently large amount of friction on the upper side of the support member 2 between the support box 1 and the support member 2, whereby said friction prevents the support member 2 from being retracted further into the support box 1.

[0034] An unlocking device (not shown in FIG. 2) can be used to release the support member 2 and the support box 1 from their mutual fixation. The clamping body 6 can be rotated clockwise about its rotary mount 14, for example by a hydraulic cylinder acting on a lever 15, in order to move the circumferential surface of the clamping body 6 away from the ramp 5, so that the support member 2 can finally be retracted into the support box 1.

Claims

1. A support device for a mobile crane, comprising: a first support segment (1) that can be fastened to the undercarriage of the mobile crane; a second support segment (2) mounted within said first support segment (1) so as to be movable relative to said first support segment (1), and comprising a support leg (3) which is movable in a vertical direction (V); a fixing device (4) that prevents the second support segment (2) from moving in the direction of movement (T) in any relative position between the first support segment (1) and the second support segment (2); A support device for a mobile crane, comprising: the fixing device (4) comprises a clamping body (6) which is held by a holding device (8) against a ramp (5) formed between the first support segment (1) and the second support segment (2) and which is attached to the first support segment (1) and the second support segment (2) in such a way that a displacement movement of the second support segment (2) in a direction away from the support leg (3) causes an increase in the force exerted by the clamping body (6) on the ramp (5), thereby fixing the second support segment (2) relative to the first support segment (1). Mobile crane support device.

2. 2. The support device for a mobile crane according to claim 1, wherein the clamp body (6) is arranged in a hollow space (7) defined by the first support segment (1) and the second support segment (2), and / or the inclined portion (5) extends obliquely with respect to the direction of movement (T) of the second support segment (2).

3. 2. The supporting device for a mobile crane according to claim 1, wherein the clamping body (6) is eccentrically attached to the first support segment (1) or the second support segment (2), in particular the holding device (8) acting on the clamping body (6) via a lever arm (15).

4. 2. Supporting device for a mobile crane according to claim 1, characterized in that the clamping body (6) is supported, in particular directly, on the first support segment (1) and the second support segment (2).

5. 2. Supporting device for a mobile crane according to claim 1, wherein the ramp (5) is assigned to the first support segment (1) or the second support segment (2).

6. 2. The support device for a mobile crane according to claim 1, wherein the clamping body (6) is roller-shaped, in particular cylindrical, and contacts the ramp (5), in particular the first support segment (1) and the second support segment (2), with its circumferential surface.

7. 2. Supporting device for a mobile crane according to claim 1, wherein the holding device (8) comprises a spring element, in particular a biasing spring element, supported on the first support segment (1) or the second support segment (2).

8. 2. The mobile crane support device of claim 1, wherein the fixing device (4) comprises an unlocking device (9) that acts in opposition to the holding device (8) to selectively separate the clamp body (6) from the ramp (5).

9. 9. Supporting device for a mobile crane according to claim 8, wherein the second support segment (2) is moved in the direction of movement (T) relative to the first support segment (1) by means of a hydraulic cylinder (10).

10. 10. The support device for a mobile crane according to claim 9, wherein the hydraulic actuation (11) of the unlocking device (9) is coupled to the hydraulic actuation (12) of the hydraulic cylinder (10) which moves the second support segment (2) in the movement direction (T).

11. 11. A support device for a mobile crane as claimed in claim 10, wherein the unlocking device (9) is activated both when the second support segment (2) moves in the direction of movement (T) away from the support leg (3) and when it moves in the opposite direction.

12. 2. A support device for a mobile crane according to claim 1, wherein the support legs (3) are provided with hydraulic support cylinders (13).

13. 2. A supporting device for a mobile crane according to claim 1, wherein the first support segment (1) is formed by a support box, the support box being movable and comprising support members on either side of the support box, each of which forms the second support segment (2).

14. A mobile crane comprising the support device of claim 1.

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