Outriggers of a mobile crane equipped with a fixing device

Abstract

To provide an improved method compared to conventional solutions, of reliably defining the positions of support members for crane operations.SOLUTION: There is provided a mobile crane support device, comprising: a first support segment 1; a second support segment 2; and a fixing device 4 having contact portions 5, 6 which are assigned to the first support segment 1 and to the second support segment 2, respectively, and which can be moved into abutment with each other in order to prevent a position-changing movement T in any relative position between the first support segment 1 and the second support segment 2. Therein the second support segment can rotate within the first support segment 1 and relative to the first support segment 1 about an axis A extending in a horizontal direction H and transversely with respect to the position-changing movement T, so that the contact portions 5, 6 can be selectively moved into contact with each other or separated from each other.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In order to provide sufficient tilt stability to a mobile crane during crane operation, their undercarriages generally comprise outriggers including four support members that can be extended and / or pivoted in a transverse direction with respect to the longitudinal axis of the undercarriage. Each of the support members comprises a support cylinder at their end facing away from the undercarriage. The support cylinder can be extended vertically and is supported on the ground by a support disk. Generally, two support members that can be extended in opposite directions to each other are arranged in the front region and the rear region of the undercarriage, respectively. Deformations and load changes during crane operation cause longitudinal forces in the support members, which may cause displacement of the support members. Unintentional longitudinal movement of the support members is generally prevented by mechanically bolting the support members. However, due to structural reasons, the number of possible bolt tightening positions is limited.

[0003] Modern designed cranes are equipped with a load torque limiter. In principle, this load torque limiter enables access to any position of the support member, thus simplifying crane operation in difficult spaces or even enabling crane operation in difficult spaces that is only possible when using a load torque limiter. However, for the reasons mentioned above, it is impossible to perform mechanical bolting at all positions of the support member, and thus it is impossible to reliably define the position of the support member. Therefore, in order to operate the crane safely, it is necessary to continuously monitor the current position of the support member, and when the support member moves away from its target position, certain crane functions need to be disabled. In DE102020212687, it is proposed to define the position of the support member using a brake rail and a brake engagement element that engages with the brake rail.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The object of the present invention is to provide an improved method compared to the conventional solutions for reliably defining the position of the support member for crane operation.

Means for Solving the Problems

[0006] This object is achieved by the subject matter of independent claim 1. The dependent claims define preferred embodiments of the invention, and equivalent claim 10 defines a mobile crane comprising the invention.

[0007] The support device of a mobile crane according to the present invention includes a first support segment that can be fastened to the chassis of the mobile crane, and a second support segment that can move relative to the first support segment within the first support segment, the second support segment being provided with support legs that can move in the vertical direction, and a fixing device that is respectively assigned to the first support segment and the second support segment and is provided with contact portions that can be moved into contact with each other to prevent the first support segment from moving in a position-changing manner at any relative position between the first support segment and the second support segment. According to the present invention, the second support segment can rotate relative to the first support segment within the first support segment about an axis extending in the horizontal direction and in the transverse direction with respect to the position-changing movement, and thus the contact portions can be selectively moved into contact with each other or separated from each other.

[0008] In this case, the first support segment can be formed by a so-called support box that takes a fixed position permanently or removably on the crane chassis. However, the first support segment may also be formed by a support member that can move translationally or pivot rotationally relative to the crane chassis and / or the support box. Therefore, the support device according to the present invention can be constructed from any number of support segments that can move rotationally or translationally relative to each other and / or relative to the crane chassis, and the translational position-changing movement thereof can be blocked by the fixing device according to the present invention.

[0009] According to the present invention, the second support segment can not only move translationally with respect to the first support segment, i.e., extend and retract again. Instead, the second support segment can pivot or tilt within the first support segment about a horizontal axis extending in a transverse direction, in particular a vertical direction, with respect to the direction in which the second support segment extends out from and can be retracted back into the first support segment. As will be explained in more detail below, this rotational movement is caused by actuating the support cylinder at the free end of the second support segment. This is because the dissipation of the force caused by the load of the crane on the ground via the outriggers of the crane results in a transverse force load on the support segment, so that the end portion of the support segment always abuts against the other support segment in any case. The present invention effectively prevents the positional change movement of the second support segment with respect to the first support segment by using this effect and the forces acting between the contact portions of the respective support segments. When the support cylinder is retracted, the transverse force load on the support segment, and thus also the force acting on the contact portion between the support segments, is canceled, thereby enabling the positional change movement of the second support segment within the first support segment again.

[0010] In the support device according to the present invention, the relative position between the two support segments is thus determined according to the vertical load in the support device due to the weight of the crane without the need for a separate actuator.

[0011] According to one embodiment, the end region of the first support segment facing the support leg - is a lower support bearing, in particular with at least one rolling element, whereby the second support segment can be supported by the first support segment during movement, the lower support bearing and / or - is an upper support bearing, in particular with at least one pressing element, whereby the second support segment can be supported by the first support segment during rotation, the upper support bearing is provided.

[0012] The support bearing portion of the first support segment as described above defines the positions where the support segments contact each other in the individual load states of the support device. Since translational relative movement occurs between the support segments that contact each other within the region of the support bearing portion disposed below the second support segment, it is advantageous to provide one or more suitable rolling elements or at least sliding elements that reduce friction in order to avoid wear in this region. When the mobile crane is supported, the support bearing portion disposed on the second support segment acts as a so-called fulcrum and must provide a corresponding large bearing surface for the second support segment in order to avoid excessive material stress. The position of this support bearing portion, in combination with the length of the portion of the second support segment left within the first support segment, greatly affects the force acting on the contact portion and thus, consequently, the ability provided by the corresponding contact portion to define the position of the second support segment relative to the first support segment.

[0013] According to another aspect, - The end region of the second support segment facing away from the support leg is an upper support bearing portion, in particular comprising at least one pressing element, whereby the second support segment can be supported by the first support segment during movement, comprising an upper support bearing portion, and / or - The second support segment is embodied such that its center of gravity is always located outside the first support segment, in particular beyond the lower support bearing portion of the first support segment.

[0014] The support bearing portion described above functions to reduce friction and wear when the second support segment is moving within the first support segment, and can comprise one or more rolling elements or at least sliding elements that reduce wear by reducing friction, such as the support bearing portion disposed below the second support segment between the first support segment and the second support segment.

[0015] It is also advantageous for the center of gravity of the second support segment to always be, i.e., at all relative positions, on the side facing away from the crane chassis from the support bearing arranged below the second support segment, so that when the support device is not exposed to a load, the portion of the second support segment arranged within the first support segment is, so to speak, automatically lifted, whereby the respective contact portions are separated from each other.

[0016] In other embodiments, the contact portions are arranged on the inner wall of the first support segment and the outer wall of the second support segment, respectively. However, it is equally conceivable that at least one of the contact portions is not arranged directly on the support segment to which it is assigned, but rather is arranged indirectly only via one or more structures arranged between the contact portion and the support segment and transmitting the prevailing forces therebetween.

[0017] In principle, it is conceivable that the contact portions, which are moved into the abutting state by the support device being exposed to a load, fix the two support segments to each other in a friction fit. However, it is equally possible for the respective contact portions to engage in a positive fit, in which, in particular, at least one of the contact portions exhibits a toothed profile or an equivalent profile suitable for establishing a positive fit between the contact portions.

[0018] In other embodiments, the fixing device comprises a release device that is biased as soon as the contact portions are moved into contact with each other and, when biased, tends to separate the contact portions from each other again, the release device comprising in particular an elastic spring. As an alternative to or in addition to the second support segment having a center of gravity located outside the first support segment, such a release device functions such that the second support segment is movable when the support device is not exposed to a load. The release device can comprise, for example, a bearing element that contacts the inner wall of the first support segment and / or its contact portion in order to introduce a biasing force generated by a biasing element, such as an elastic spring, into the first support segment, where the bearing element can be made, in part or in whole, of a friction-reducing material in order to avoid wear.

[0019] According to other embodiments, the positional change movement of the second support segment relative to the first support segment is generated by a hydraulic cylinder. In principle, any suitable device, such as a mechanical drive device comprising a gear system, can be considered for this purpose.

[0020] According to other embodiments, the support legs can comprise hydraulic support cylinders supported on the ground, for example via support disks.

[0021] In other embodiments, the first support segment is formed by a support box, the support box comprising support members that expand and contract on both sides of the support box and each form a second support segment.

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

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

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 schematically shows the structure and function of a support device according to the present invention based on individual pairs of a first support segment or support box 1 and a second support segment or support member 2. The support member 2 extends into the support box 1 and can be extended outward from the support box 1 in the horizontal direction T to the right and retracted back into the support box 1 to the left by a hydraulic cylinder (not shown). To support mobile cranes on both sides, the support box 1 further houses a second support member (not shown) that can be extended outward from the support box 1 to the left and retracted into it to the right in the same manner as the first support member 2.

[0026] The free end of the support member 2 facing away from the support box 1 and the crane chassis is provided with a support leg 3. The support leg 3 can move in the vertical direction V and includes a support disk and a piston rod of a hydraulic cylinder 17 connected to it by a joint.

[0027] As shown in FIG. 1, when the support device is not exposed to a load, a hydraulic cylinder (not shown) can move the support member 2 in the moving direction T with respect to the support box 1. The support member 2 is stationary by its support bearing portion 12 embodied as a sliding element and by the support bearing portion 8 of the support box 1 having at least one rolling element 7, and slides or rolls off on the inner surface of the support box 1 by the bearing portion 12 and / or 8. The center of gravity S of the support member 2 is located beyond the support bearing portion 8 and / or outside the support box 1, thus generating a clockwise tilting torque, whereby the distance between the contact portions 5 and 6 remains open.

[0028] As soon as the support member 2 extends out of the support box 1 by a desired length (the support member (not shown) on the left hand side can extend out of the support box 1 by any other length), the support leg 3 is extended vertically downward by the hydraulic cylinder 17 in order to support the mobile crane. Due to the contact force generated when the support leg contacts the ground, the support member 2 rotates counterclockwise about the axis A with respect to the support box 1 and / or tilts in the regions of the support bearings 8 and 10. Subsequently, the support member 2 is supported by the support box 1 via the support bearing 10, where the contact surface 6 arranged on the outer surface 14 of the support member 2 and the contact surface 5 arranged on the inner surface 13 of the support box 1 move into a contacting state. In the illustrated example, the contact surfaces 5, 6 are embodied as corresponding toothed profiles and mesh with a positive fit. In order to enable the contact surface 6 to engage over the entire movement range of the support member 2, the contact surface 5 extends inside the support box 1 to the length required for this purpose. Due to the positive fit engagement between the contact surface 5 and the contact surface 6, the support member 2 can no longer move in the moving direction T.

[0029] As soon as, after use of the crane, the support leg 3 is lifted vertically upward again by the hydraulic cylinder 17, the support device is released from the load. Due to the position of the center of gravity S and the biasing force exerted by the spring 16 on the telescopic box 1 via the sliding block 15, a clockwise rotational movement about the axis A as the stop occurs in the regions of the support bearings 8 and 10, the contact portions 5 and 6 are separated from each other again, presenting the state shown in FIG. 1. When the support device is not exposed to the load, the support member 2 can move again.

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) movable within and relative to said first support segment (1), said second support segment (2) comprising a support leg (3) movable in a vertical direction (V); a fixing device (4) assigned to said first support segment (1) and to said second support segment (2), respectively, and comprising contact parts (5, 6) which can be moved into abutment with each other to prevent a repositioning movement (T) of said second support segment (2) in any relative position between said first support segment (1) and said second support segment (2); A support device for a mobile crane comprising: characterised in that the second support segment can rotate within and relative to the first support segment (1) about an axis (A) extending in a horizontal direction (H) and transverse to the repositioning movement (T), so that the contact portions (5, 6) can be selectively moved into abutment with each other or separated from each other, Mobile crane support device.

2. The end region of the first support segment (1) facing the support leg (3) has a lower support bearing (8) by means of which the second support segment (2) can be supported on the first support segment (1) during the movement, and / or an upper support bearing (10) by means of which said second support segment (2) can be supported on said first support segment (1) during rotation; 2. The mobile crane support apparatus of claim 1, comprising:

3. the end region of the second support segment (2) facing away from the support leg (3) is provided with an upper support bearing (12) by means of which the second support segment (2) can be supported on the first support segment (1) during movement, and / or the second support segment (2) is embodied in such a way that its centre of gravity (S) is always located beyond the lower support bearing (8) of the first support segment (1), so that the second support segment (2) can be supported on the first support segment (1) during movement; 2. The support apparatus for a mobile crane according to claim 1.

4. 2. The supporting device for a mobile crane according to claim 1, wherein the contact portions (5, 6) are respectively arranged on an inner wall (13) of the first supporting segment (1) and on an outer wall (14) of the second supporting segment (2).

5. 2. A mobile crane support arrangement as claimed in claim 1, wherein each of said contact portions (5, 6) interlock with a positive fit.

6. 2. A supporting device for a mobile crane as claimed in claim 1, wherein the fixing device (4) comprises a release device (15) which is biased as soon as the contact parts (5, 6) are moved into abutment with each other and which, when biased, tends to separate the contact parts (5, 6) from each other again.

7. 2. The support device of a mobile crane according to claim 1, wherein the repositioning movement (T) of the second support segment (2) relative to the first support segment (1) is generated by a hydraulic cylinder or a mechanical drive.

8. 2. The supporting device for a mobile crane according to claim 1, wherein the supporting leg (3) is provided with a hydraulic supporting cylinder (17).

9. 2. The 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 provided on both sides with movable support members each forming a second support segment (2).

10. A mobile crane comprising the support device according to claim 1.

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