Locking device for a reversibly extendable support bracket of a motor vehicle

Abstract

The invention relates to a locking device (30) for a reversibly extendable support bracket (18) of a motor vehicle (1), in particular a mobile crane, comprising a brake rail (32) which is fixed on the support bracket (18) or a support box (20) of the motor vehicle (1) in the intended assembly state, a brake engagement element (36) which is arranged on the support box (20) of the motor vehicle (1) or on the support bracket (18) in the intended assembly state and is reversibly adjustable relative to the brake rail (32), an adjustment drive which is coupled to the brake engagement element (36) by means of force transmission in the intended assembly state and is configured to apply a braking force to the brake engagement element (36), and a controller (44) which is configured to actuate the adjustment drive to apply or reduce the braking force when the support bracket (18) is adjusted relative to the support box.

Description

[0001] The invention relates to a locking device for a reversibly extendable outrigger of a motor vehicle. Furthermore, the invention relates to an undercarriage of a motor vehicle with such a locking device. The invention also relates to a motor vehicle, in particular a mobile crane, with such an undercarriage.

[0002] Motor vehicles equipped with lifting or handling devices, such as a telescopic crane boom, a lifting platform, or similar equipment, typically include outriggers that can be extended or swung out laterally from a support box. Usually, there are four such outriggers, each with a telescopic foot. To operate the crane boom or similar device, the entire vehicle is placed on these feet. This widens the vehicle's footprint, allowing the lifting platform, crane boom, or similar equipment to extend further laterally without increasing the risk of tipping.

[0003] DE 31 24 029 A1 describes an adjustment mechanism for such support brackets on construction machinery. This support bracket adjustment mechanism comprises a guide profile and a support bracket or extension profile guided within it. Preferably, the two parts are displaced relative to each other in a horizontal, or optionally inclined, plane. A preferably hydraulic motor engages directly or indirectly, via a reduction gear and a spur gear, pinion gear, or sprocket, with a rack, slotted bar, or chain on the arm to be displaced. The drive unit, optionally including a support roller, forms a movable, boltable assembly and can be connected to the fixed guide arm or the adjustable support arm.

[0004] DE 10 2013 001 474 A1 describes a device for telescopic support beams. This device comprises a support box, at least one first support beam, and at least one second support beam, which are telescopically extendable. The second support beam is mounted in the support box in a steplessly telescopic manner. In a first support range, the first support beam is retracted, allowing stepless adjustment by means of the second support beam. In a second support range, the first support beam is extended, again allowing stepless adjustment by means of the second support beam.

[0005] DE 10 2016 101 977 A1 describes a linear drive system. This system comprises a guide device and a carriage device that can travel along the guide device. The braking device includes a brake rail and a brake carriage guided along the brake rail, the carriage device being braked by friction between the brake rail and the brake carriage. The brake carriage has two brake units, each with a wedge section and a locking section. A brake energy storage device is associated with the brake carriage, which is designed and configured to press the brake units together along the wedge sections in a force direction in a braking position, thereby displacing the brake units transversely to a longitudinal axis of the brake rail in opposite directions and pressing the locking sections against the brake rail, thus braking the brake carriage.The brake energy storage device is assigned an actuator which is suitable and designed to pre-tension the brake energy storage device in a release position and to push the brake units apart against the direction of force of the brake energy storage device, so that the damping areas can be released from the brake rail.

[0006] The invention is based on the objective of improving the operation of a motor vehicle, in particular a motor vehicle with support beams.

[0007] This problem is solved according to the invention by a locking device having the features of claim 1. Furthermore, this problem is solved according to the invention by an undercarriage having the features of claim 3. This problem is also solved according to the invention by a motor vehicle having the features of claim 4. Finally, this problem is solved according to the invention by a motor vehicle having the features of claim 5. Advantageous and partly inventive embodiments and further developments of the invention are set forth in the dependent claims and the following description.

[0008] The locking device according to the invention is designed and intended for use in a motor vehicle that has a reversibly extendable outrigger, in particular in a mobile crane. The locking device includes a brake rail which, in the intended assembly state, is fixed to the outrigger or an outrigger box of the motor vehicle. Furthermore, the locking device includes a brake engagement element which, in the intended assembly state, is arranged—or, conversely, arranged—on the outrigger box of the motor vehicle or on the outrigger and is reversibly adjustable relative to the brake rail. The locking device also includes an adjustment drive which, in the intended assembly state, is coupled to the brake engagement element by means of power transmission and is configured to apply a braking force to the brake engagement element (and thus also by means of the brake engagement element).Furthermore, the locking device includes a controller designed to actuate the adjustment drive to apply or reduce the braking force when the support bracket is moved relative to the support box. The controller (also called control unit) is configured to reduce or eliminate the braking force when the support bracket is moved and to reapply the braking force when the support bracket is in its intended position.

[0009] The brake engagement element is advantageously decoupled from a typically hydraulic displacement drive of the support carrier, which serves to extend and retract the support carrier out of or into the support box, and in particular is also designed independently of it.

[0010] The locking device according to the invention thus advantageously makes it possible to lock the support beam at virtually any position along its extension or retraction path (relative to the support box) by applying braking force. Furthermore, conventionally used locking elements, in particular locking bolts, by means of which the support beam is bolted and thus fixed and secured in its extended position, can be advantageously omitted. Previously, only a relatively small number of discrete extension positions were possible using the locking bolts. Since these locking bolts usually have to be operated by personnel, the locking device according to the invention also reduces operating effort.

[0011] In one embodiment according to the invention, the brake rail is mounted on or integrated into a support element of the support bracket as an elongated brake disc. In this case, the brake engagement element is formed by—or includes—a brake caliper with brake pads that can be pressed against the brake disc on both sides. In other words, the brake rail and the brake engagement element form a conventional friction brake similar to a disc brake, with the brake disc being designed as a straight, elongated plate. The "brake disc" is optionally designed as part of the support element, for example, as the edge region of a transverse flange of a T- or I-beam profile (the latter commonly known as a double-T beam). This advantageously reduces the number of individual components required. Furthermore, such a friction brake allows for free adjustability of the support bracket.

[0012] In an alternative embodiment, the brake rail has a profiled interlocking surface. Preferably, the interlocking surface is toothed, i.e., provided with a tooth profile whose tooth flanks extend transversely or at least obliquely to the direction of movement of the support bracket. In this case, the brake engagement element has an interlocking piece with a complementary profile that can be inserted into the profile of the interlocking surface. Thus, if the interlocking surface is toothed, the interlocking piece is also provided with a profile that is expediently toothed in the same way as the interlocking surface. In this case, it is understood that only discrete positions of the support bracket can be locked, although a significantly greater number of intermediate positions is possible compared to locking bolts – at least with a sufficiently small tooth pitch.The claw-like element is optionally designed as a relatively short, straight rail with a small number of teeth. Optionally, the claw-like element may have only one tooth. Preferably, however, the claw-like element has at least two or three teeth, e.g., up to eight or ten.

[0013] In another alternative embodiment, the brake rail has a locking cam that extends along an axis of movement of the support beam. Furthermore, this locking cam is inclined at approximately every point (along its longitudinal extent) to the axis of movement of the support beam. Preferably, the locking cam is also oriented at approximately every point at an angle to the perpendicular to the axis of movement. This perpendicular, together with the axis of movement of the support beam, forms a plane in which the locking cam lies. In this embodiment, the brake engagement element also has a cam block that is movable transversely to the axis of movement of the support beam (i.e., movably hinged) and can be fixed in its current position by means of the adjustment drive. Thus, when the support beam is adjusted, the cam block can move along the locking cam in the usual manner.However, if the cam block is fixed in its current position, i.e. secured against movement, the relative movement of the locking cam and thus of the support beam is also blocked.

[0014] In its simplest form, the locking cam is designed as a straight line running at an angle to the axis of movement of the support beam. However, to achieve the steepest possible angle between the locking cam and the axis of movement, the locking cam is preferably designed in a meandering shape. In particular, the locking cam follows a wave-like curve, for example, a sinusoidal path along the brake rail. In this case, "at an angle at approximately every point" means, in particular, that, except for the inflection points of the meandering locking cam, a tangent applied to the locking cam is at an angle to the axis of movement.

[0015] In a practical embodiment, the adjusting drive, particularly in each of the embodiments described above, includes a hydraulic cylinder with a locking valve. Optionally, this cylinder is arranged such that the cam block can also be activated in a direction transverse to the axis of movement of the support beam. In this case, the locking or braking effect is achieved by fixing the cam block transversely to the axis of movement of the support beam, thus clamping it against the locking cam, which runs obliquely to the axis of movement and therefore also obliquely to the adjustment direction of the cam block. Alternatively, the cam block can also be moved against the support beam for locking. This results in an additional braking effect.The locking valve advantageously offers the possibility of keeping the applied braking force approximately force-free by "fixing" the hydraulic pressure applied by the hydraulic cylinder (especially to the brake pads, the claw piece or the cam block) in the system of the adjusting drive.

[0016] The undercarriage according to the invention for the aforementioned (in particular land- and wheel-based) motor vehicle, preferably for the mobile crane, comprises the support box described above for receiving the support beam, and optionally also the support beam arranged therein. Furthermore, the undercarriage also comprises the locking device described above.

[0017] The motor vehicle according to the invention (in particular land- and wheel-based), preferably the mobile crane, has the undercarriage described above.

[0018] Therefore, the motor vehicle has the support box described above for receiving the support bracket, and possibly also the support bracket arranged therein. Furthermore, the motor vehicle also has the locking device described above.

[0019] Thus, both the undercarriage and the motor vehicle also feature the brake rail, which, in its intended assembly state, is fixed to the support bracket or the support box of the motor vehicle, as well as the brake engagement element, which, in its intended assembly state, is arranged—conversely—on the support box of the motor vehicle or on the support bracket and is reversibly adjustable relative to the brake rail. Furthermore, both the undercarriage and the motor vehicle also feature the adjustment drive, which, in its intended assembly state, is coupled to the brake engagement element via power transmission and is configured to apply the braking force to the brake engagement element, as well as the controller, which is configured to actuate the adjustment drive to apply or reduce the braking force when the support bracket is moved relative to the support box.

[0020] Optionally, the outrigger (or outriggers) can be reversibly inserted into the outrigger box to reduce the overall weight of the vehicle, particularly when transporting it on roads, especially a mobile crane. Therefore, the outrigger is not necessarily part of at least the undercarriage.

[0021] In a further embodiment, which also constitutes an invention in its own right, the motor vehicle according to the invention, in particular the mobile crane, has an undercarriage and a superstructure which is rotatably mounted about a pivot axis perpendicular to the undercarriage by means of a rotary joint. The motor vehicle also has a locking device – designed in particular comparable to the locking device described above. In this embodiment, however, this locking device has an annular brake disc arranged on the rotary joint and rotationally fixed to the undercarriage or the superstructure, as well as a brake engagement element that is rotationally fixed to the superstructure or the undercarriage and is designed essentially analogously to the brake engagement element described above. The latter is formed by a brake caliper with brake pads that can be pressed against the brake disc on both sides.The locking device also features an adjustment drive, which is coupled to the brake engagement element via power transmission and is configured to apply a braking force to the brake engagement element, as well as a controller (also: control unit) which is configured to actuate the adjustment drive to apply or reduce the braking force when the upper structure is moved relative to the lower structure. In other words, the slewing ring between the upper and lower structures has a disc brake system for locking the upper structure relative to the lower structure.

[0022] The controller (or control unit) can be designed as a non-programmable electronic circuit within the scope of the invention and, for example, represent an independent control unit for the locking device. However, the controller can also be a microcontroller within the scope of the invention, in which the functionality for applying the braking force is implemented as a software module. This software module can, in particular, form part of a comprehensive control software (firmware) for the actuator motor.

[0023] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 in a schematic view of the rear of a mobile crane, which in its intended operating state is supported on outriggers, Fig. 2 in a schematic, side view detail a support box with a partially extended support beam and a locking device, Fig. 3 in a schematic detail view of a top side the support box with the support bracket and the locking device, Fig. 4 in view according to Fig. 2 an alternative embodiment of the locking device, Fig. 5, Fig. 6 in view according to Fig. 2 or Fig. 3 another embodiment of the locking device, and Fig. Figure 7 shows a schematic top view of a rotary joint between a crane superstructure and a crane undercarriage with a locking device.

[0024] Corresponding parts in all figures are always marked with the same reference symbols.

[0025] In Fig. Figure 1 is a land-based, wheeled motor vehicle, specifically a mobile crane 1, shown schematically. The mobile crane 1 has an undercarriage 4, which carries a chassis with wheels 2, and a superstructure 6. The superstructure 6 is pivotable about a pivot axis 8 oriented perpendicular to the undercarriage 4. The superstructure 6 carries a crane boom 10, which has several telescoping segments 12 and which can be "tilted" about a luffing axis 14, i.e., pivoted at an angle to the ground 16. To ensure the mobile crane 1 has a stable position even when the superstructure 6 is laterally extended and the crane boom 10 is fully extended (see Figure 1), the superstructure 6 is equipped with a pivot axis 8. Fig. 1) to enable, the mobile crane 1 also includes so-called outriggers 18. These are housed in outrigger boxes 20 (see below). Fig. 2), which are arranged in the undercarriage 4, are retractable and extendable. The support beams 18 have a support element 22, designed as an I-profile in the present embodiments, and a telescopic support foot 24 (not shown here).

[0026] As an alternative to the I-profile, the support element 22 is designed in further embodiments not shown in detail as a T-profile, rectangular profile or the like.

[0027] Typically, the support bracket 18 is extended laterally and secured in one of a few, e.g., three discrete extension positions, specifically fixed against displacement by means of locking pins. This results in only a relatively small range of motion between the retracted and extended positions.

[0028] Furthermore, the operating effort is high, as the locking pins usually have to be placed by hand.

[0029] Therefore, the mobile crane 1 has a locking device 30 that makes it possible to fix the outrigger 18 at almost any extension position. In an exemplary embodiment, shown in more detail in Fig. 2 and Fig. 3. The locking device 30 has a brake rail 32 formed on the upper flange (or "upper transverse flange") of the I-profile of the support element 22. The brake rail 32 corresponds to a straight brake disc elongated along an axis of movement 34 of the support beam 18. The locking device 30 further includes a brake engagement element 36, which in the case of the brake disc is formed by a brake caliper 38 that holds adjustable brake pads 40 against the brake rail 32 (from both sides, i.e., from above and below). To adjust the brake pads 40 and thus generate a braking force, the locking device 30 includes an adjustment drive, which here is formed by corresponding brake cylinders 42 that are hydraulically driven and in contact with the respective brake pad 40. The brake engagement element 36, together with the adjusting drive, thus forms a “four-piston brake”.The adjusting drive also includes a locking valve, which is not shown, and which makes it possible to maintain the applied brake pressure in the brake cylinder 42 even if a hydraulic pump fails.

[0030] The locking device also includes a controller 44 for controlling the adjustment drive. This controller is coupled to the brake engagement element 36, specifically to the adjustment drive. The controller 44 is also coupled to an extension cylinder 46. The latter serves to extend the support bracket 18 out of or retract it into the support box 20.

[0031] The controller 44 is configured to release the applied braking force during the extension phase of the extension cylinder 46. Once the adjustment process is complete and the respective support bracket 18 is in its target position, the controller 44 activates the adjustment drive, specifically by switching hydraulic pressure to the brake cylinders 42, to fix the support bracket 18 in its position.

[0032] In Fig. Figure 4 shows an alternative embodiment of the brake rail 32. In this embodiment, the brake rail is designed as a type of rack, i.e., with a toothed profile. The brake engagement element 36 has a "toothed section 48" that is complementary to the toothed profile of the brake rail 32. This toothed section can be hydraulically—or optionally electrically—engaged against the brake rail 32 and thus into the toothed profile formed therein. This results in a positive fit. The toothed profile therefore forms an interlocking surface in which the toothed section 48 can interlock. Otherwise, the functions of the controller 44, the extension cylinder 46, and the like correspond to the embodiment described above.

[0033] In Fig. 5 and Fig. Figure 6 shows a further embodiment of the locking device 30. A locking cam 50 with a sinusoidal profile is integrated into the brake rail 32. The locking cam 50 is thus, except at its extremes, always inclined to the axis of movement 34. The brake engagement element 36 has a cam block 52 that is movable in a transverse direction 54, which is oriented perpendicular to the axis of movement 34 and lies in the plane of the upper chord of the support element 22. Under the influence of the braking force, the adjusting drive is configured to block the cam block 52 in its movement along the transverse direction 54. This prevents movement of the support beam 18 due to the clamping of the cam block 52 in the locking cam 50.

[0034] In Fig. Figure 7 schematically shows a rotary joint 60 between the undercarriage 4 and the superstructure 6. To secure the rotary joint 60, a device comparable to the embodiment shown in Figure 7 is used. Fig. 2 and Fig. 3. A locking device 62 is assigned to the superstructure. This includes a brake disc 64 as a brake rail and a (here four-piston) brake caliper 66 as a brake engagement element. This allows the superstructure 6 to be locked in any desired rotational position relative to the undercarriage 4. This embodiment is fundamentally independent of the locking device 30 described above, but can nevertheless be used in conjunction with it in the mobile crane 1.

[0035] The subject matter of the invention is not limited to the embodiments described above. Rather, further embodiments of the invention can be derived by a person skilled in the art from the foregoing description. In particular, the individual features of the invention and their various configurations described with reference to the different embodiments can also be combined with one another in other ways. Reference symbol list 1 mobile crane 2 wheel 4 undercarriages 6 upper carriages 8 axis of rotation 10 crane booms 12 segments 14 rocker axle 16 Floor 18 support beams 20 support boxes 22 Support element 24 support leg 30 Locking device 32 Brake rail 34 axis of movement 36 Brake intervention element 38 brake caliper 40 brake pads 42 brake cylinders 44 Controller 46 Extension cylinders 48 tooth piece 50 Locking scenery 52 Scenery stone 54 Transverse direction 60 swivel joint 62 Locking device 64 brake disc 66 brake caliper

Claims

[1] Locking device (30) for a reversibly extendable support beam (18) of a motor vehicle (1), in particular a mobile crane, comprising - a brake rail (32) which, in the intended assembly state, is fixed to the support bracket (18) or a support box (20) of the motor vehicle (1), - a brake engagement element (36) which, in the intended assembly state, is arranged on the support box (20) of the motor vehicle (1) or on the support bracket (18) and is reversibly adjustable relative to the brake rail (32), - an adjustment drive (42) which, in the intended assembly state, is coupled to the brake engagement element (36) for power transmission purposes and is configured to apply a braking force to the brake engagement element (36), and - a controller (44) configured to actuate the adjustment drive (42) to apply or reduce the braking force when the support carrier (18) is adjusted relative to the support box, wherein the controller (44) is configured to reduce or eliminate the braking force when the support carrier (18) is moved and to apply the braking force when the support carrier (18) is in its intended position, wherein the brake rail (32) is applied to or integrated into a support element (22) of the support carrier (18) as an extended brake disc, and wherein the brake engagement element (36) is formed by a brake caliper (38) with brake pads (40) that can be pressed against the brake disc on both sides, or wherein the brake rail (32) has a profiled interlocking surface and the brake engagement element (36) has a complementarily profiled interlocking piece (48) that can be inserted into the profile of the interlocking surface, or wherein the brake rail (32) has a locking cam (50) extending along an axis of movement (34) of the support beam (18), which is inclined at approximately every point to the axis of movement (34) of the support beam (18), wherein the brake engagement element (36) has a cam block (52) movable transversely to the axis of movement (34) of the support beam (18), which can be fixed in a position by means of the adjusting drive (42). [2] Locking device (30) according to claim 1, wherein the adjusting drive (42) has a hydraulic cylinder with a locking valve. [3] Undercarriage (4) for a motor vehicle, in particular a mobile crane (1), comprising - a support box (20) for receiving a support beam (18) or with a support beam (18) arranged therein, and - a locking device (30) according to claim 1 or 2. [4] Motor vehicle, in particular mobile crane (1) comprising a chassis (4) according to claim 3. [5] Motor vehicle, in particular mobile crane (1), comprising an undercarriage (4) and a superstructure (6) which is rotatably mounted about a pivot axis (8) perpendicular to the undercarriage (4) by means of a rotary joint (60), and a locking device (62) comprising an annular brake disc (64) arranged on the rotary joint (60) and rotationally fixed to the undercarriage (4) or the superstructure (6), a brake engagement element formed by a brake caliper (66) with brake pads that can be pressed against the brake disc (64) on both sides, an adjustment drive which is coupled to the brake engagement element by means of power transmission and is configured to apply a braking force to the brake engagement element, and a controller which is configured toWhen the upper carriage (6) is adjusted relative to the undercarriage (4), the adjustment drive is used to apply or reduce the braking force.

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