Method and arrangement for active motion control on a vehicle with a tiltable dump box

Abstract

The invention relates to a method and an arrangement for actively damping a vehicle (1) in motion, the vehicle comprising a dump box (10), which may be actuated around a pivot point (PP) between a flat transport position and a tilted dumping position by mean of at least one hydraulic cylinder (11). A sensor (15) is arranged to monitor the condition of the road on which the vehicle (1) is being driven and a control unit (CU) is configured to receive information from the sensor (15) and to control the at least one hydraulic cylinder (11) of the dump box (10) in response thereto, wherein in response to a road irregularity (20) being detected by the sensor (15), the control unit (CU) being configured to predict whether the road irregularity (20) would cause the vehicle to oscillate when passing over the road irregularity (20) and to control the at least one hydraulic cylinder (11) of the dump box (10) to tilt the dump box (10) to dampen the effect of the road irregularity (20) and attenuate the oscillation. The invention also relates to a vehicle comprising such an arrangement.

Description

[0001] METHOD AND ARRANGEMENT FOR ACTIVE MOTION CONTROL ON A VEHICLE

[0002] WITH A TILTABLE DUMP BOX

[0003] TECHNICAL FIELD

[0004] The invention relates to an arrangement and a method of active motion control on a vehicle with a tiltable dump box. The invention also relates to a vehicle comprising such an arrangement, and specifically to a heavy duty mobile underground mining vehicle comprising such an arrangement.

[0005] BACKGROUND

[0006] Rock excavation, in particular underground rock excavation, but also e.g. surface mining and construction, may be carried out using various techniques, where excavation using drilling and blasting technology is a commonly used method. The excavation may comprise creation of e.g. a rock cavity having a predefined shape and geographical location. This may be the case, for example, when creating tunnels or other kinds of underground cavities.

[0007] Excavation using drilling and blasting is, in general, carried out in a manner in which drilling is performed in rounds, where a round of holes is drilled which are subsequently loaded with explosives to blast the rock. The broken rock is then removed, and a new round of holes are drilled to blast a subsequent portion of the cavity to be created. This procedure is often repeated a number of times until excavation of the desired cavity has been completed.

[0008] The excavation may generate large volumes of broken rock to be transported away, and mine trucks may be utilised to facilitate such rock removal. These mine trucks may be of substantial dimensions. For example, with regard to underground mine trucks, these may be designed to carry loads e.g. in the order of 10-100 metric tonnes of load. Surface mine trucks may be designed to carry even higher loads, such as hundreds of tonnes of load. These trucks in general comprise a frame, which is exposed to substantial levels of stress e.g. during loading and unloading operations, and also during hauling of payload.

[0009] Further, these trucks are made for operation in off-road environments to carry or haul heavy loads, specifically in a dump box. Such mobile work machines usually have a heavy-duty build with a heavy-duty power source providing power to various work implements and propelling the wheels of the mobile work machine. Various applications may require the mobile work machine to deliver a high-torque, low-speed power to the wheels, or to various implements, in loaded operational conditions. At other times, relatively low-torque, high-speed operation may be required of the work vehicle, for example when the vehicle is unloaded and / or in transit.

[0010] To facilitate both the high torque demands at times and the high speed demands at other times, the mobile work machines may be furnished with heavy-duty axle assemblies that incorporate or cooperate with various gear assemblies to provide a robust and reliable drive to the wheels. The axle assemblies may transmit power to the wheels from a primary motor solely, or they may be powered themselves, e.g. by electric or hydraulic motors.

[0011] In the technical field of vehicles with a tiltable dump box, the weight acting on the wheels makes it challenging to achieve a wheel suspension adapted for both when the dump box is empty and when it is heavily loaded. In many heavy duty mobile underground mining vehicles, the front wheels, which only carry a minor portion of the load in the dump box, are suspended, whereas the rear set of wheels are arranged on a non-suspended heavy- duty axle assembly. When such a vehicle is driven an a fully loaded the state the vehicle will only be driven at relatively low speed at which the dampening provided by the airfilled tyres will be sufficient to maintain vibrations and oscillations on the vehicle at an acceptable level.

[0012] However, such an un-dampened axle assembly will not be optimal for driving the unloaded vehicle at a higher speed. An alternative for such a vehicle may be to provide a suspension on the cab, such that the operator of the vehicle, typically positioned in the cab, will be protected from any oscillations experienced by the axles of the vehicle.

[0013] It would however be advantageous to achieve a method and a system overcoming, or at least alleviating, at least one or some of the drawbacks of the prior art. In particular, it would be advantageous to find a reliable method and system for driving a vehicle with a tiltable dump box in bumpy conditions.

[0014] SUMMARY OF THE INVENTION

[0015] It is an object of the invention to provide a reliable manner of controlling a vehicle with a tiltable dump box in motion so as to be driven in a comfortable manner.

[0016] According to a first aspect the invention relates to a method of controlling a vehicle in motion, the vehicle comprising a dump box that is configured to be actuated around a pivot point between a flat position and a tilted position by means of an actuator, the method comprising the steps of: monitoring by means of a sensor a condition of a road on which the vehicle travels, the sensor being configured to send signals regarding the monitored condition to a control unit, when a road irregularity is detected by the sensor the control unit determining whether the road irregularity is of a magnitude that will cause an oscillation of the vehicle when passing over the road irregularity, if the control unit determines that the road irregularity will cause an oscillation of the vehicle, tilting the dump box to dampen the effect of the road irregularity and to attenuate the oscillation of the vehicle.

[0017] Thereby, the invention provides an efficient manner of achieving an attenuation of oscillations caused by road irregularities to provide a more comfortable ride for the vehicle and its operator.

[0018] In embodiments of the method, the vehicle comprises a front set of wheels and a rear set of wheels, the dump box being tilted as the rear set of wheels passes over the road irregularity.

[0019] This provides an efficient manner of predicting when the rear set of wheels will pass over the road irregularity.

[0020] In embodiments of the method, the sensor is arranged at the front set of wheels.

[0021] In embodiments of the method, the control unit is configured to receive signals from the sensor regarding the road irregularity and from a speedometer regarding a current velocity of the vehicle and to, based on the signals regarding the road irregularity and current velocity of the vehicle, determine when to tilt the dump box.

[0022] In embodiments of the method, the detected road irregularity is a bump on the road, tilting the dump box upwards with respect to the pivot point when passing over the road irregularity.

[0023] In embodiments of the method, the dump box is tilted upwards with respect to the pivot point when or after the rear set of wheels passes over the highest point of the bump. In embodiments of the method, when the detected road irregularity is a hole in the road, the dump box is tilted downwards with respect to the pivot point when passing over the road irregularity.

[0024] In embodiments of the method, the dump box is tilted downwards when or after the rear set of wheels passes the lowest point of the road irregularity.

[0025] According to a second aspect the invention relates to an arrangement for controlling a vehicle in motion, the vehicle comprising: a set of front wheels and a set of rear wheels, a dump box configured to be actuated around a pivot point between a flat position and a tilted position by means of an actuator, wherein the arrangement comprises: a sensor for monitoring a condition of a road on which the vehicle travels, a control unit configured to receive information regarding the monitored condition from the sensor and to control the actuator in response thereto, wherein in response to a road irregularity being detected by the sensor, the control unit being configured to determine whether the road irregularity will cause an oscillation of the vehicle when passing over the road irregularity and to control the actuator to tilt the dump box to dampen the effect of the road irregularity and attenuate the oscillation of the vehicle.

[0026] In embodiments of the arrangement the control unit, when the detected road irregularity is a bump on the road, is configured to control the actuator to tilt the dump box upwards with respect to the pivot point when the set of rear wheels passes over the road irregularity.

[0027] In embodiments of the arrangement the control unit, when the detected road irregularity is a hole in the road, is configured to control the actuator to tilt the dump box downwards with respect to the pivot point when the set of rear wheels passes over the road irregularity.

[0028] In embodiments of the arrangement the sensor is arranged at the set of front wheels and arranged to detect when the set of front wheels passes over the road irregularity, wherein the control unit is configured to control the actuator to tilt the dump box with respect to the pivot point as the rear wheels passes over the road irregularity. In embodiments of the arrangement the set of front wheel include a suspension system, wherein the sensor is arranged in the suspension system to detect when the set of front wheels are either pushed upwards or allowed to move downwards with respect to the suspension system.

[0029] In embodiments of the arrangement the dump box is configured to be positioned in a level position when the vehicle is in motion, which level position allows the dump box to be adjusted both upwards and downwards with respect to the pivot point.

[0030] In embodiments of the arrangement the actuator is a hydraulic cylinder, wherein the arrangement comprises at least one hydraulic accumulator for rapidly actuating the hydraulic cylinder to rapidly move the dump box upwards or downwards with respect to the pivot point.

[0031] Thereby, a rapid tilting of the dump box may be achieved, and with that, a high acceleration of the dump box, which will actively compensate for the momentum upwards caused by the irregularity of the road.

[0032] In embodiments of the method, the vehicle comprises a front set of wheels and a rear set of wheels, and wherein the sensor is arranged at the front set of wheels and the dump box is tilted as the rear set of wheels passes over the road irregularity.

[0033] According to a third aspect the invention relates to a vehicle comprising an arrangement as described above, wherein the vehicle has a tiltable dump box.

[0034] Typically, the vehicle may be a heavy duty mobile underground mining vehicle.

[0035] The invention provides a manner of providing an active damping of a vehicle with a tiltable dump box, which is usable both when the vehicle is driven in a loaded condition, i.e. with a load in the dump box, and specifically in an unloaded condition with an empty or almost empty dump box.

[0036] Other embodiments of the invention according to the three aspects and advantages thereof will be apparent from the detailed description and the appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Below, specific embodiments of the invention will be described with reference to the appended drawings, of which:

[0038] Fig. 1 is a schematic view of a vehicle on which the invention may be implemented,

[0039] Fig. 2 shows the vehicle in Fig. 1 with a slightly tilted dump box,

[0040] Fig. 3 is a detailed view of front axle of the vehicle shown in Fig. 1 ,

[0041] Fig. 4 is a detailed view of rear axle of the vehicle shown in Fig. 1 , and

[0042] Fig. 5 is a schematic illustration of the oscillations of an undampened vehicle, a moderately dampened vehicle, and a fully dampened vehicle.

[0043] DETAILED DESCRIPTION OF THE SHOWN EMBODIMENTS

[0044] In Figs. 1 and 2, a vehicle 10 in accordance with an embodiment of the invention is schematically shown. The vehicle comprises a dump box 10 that may be actuated around a pivot point PP between a flat transport position and a tilted dumping position by means of an actuator 11 , typically in the form of at least one hydraulic cylinder. The vehicle may be a heavy duty mobile underground mining vehicle.

[0045] The vehicle comprises a front set of wheels 2 arranged to rotate about a front axis FA, and a rear set of wheels 3 arranged to rotate about a rear axis RA. In the drawings, the rear right wheel is removed to expose the rear axle portion.

[0046] In Fig. 1 , the vehicle 10 vehicle is shown just after the front set of wheels 2 has passed over a road irregularity 20 in the form of a bump on the road. The bump will cause the front axle that carries the front set of wheels 2 to move upwards. In the shown embodiment the vehicle comprises a suspension system on the front set of wheels 2 such that the front set of wheels 2 are allowed to move upwards with respect to chassis 8 of the vehicle.

[0047] Further a sensor 15 is arranged, of which a possibel position is schematically illustrated in the Figs. 1 and 2.

[0048] The sensor 15 is arranged to monitor the condition of the road on which the vehicle 1 is being driven. In the illustrated drawing the sensor 15 is arranged at the front set of wheels 2 and will just have monitored the presence of the road irregularity 20 and delivered a signal respondent to the monitored condition to a control unit CU arranged on the vehicle 1. The sensor 15 may e.g. be an optical sensor or a motion detection sensor.

[0049] In response to the monitored road irregularity 20 detected by the sensor 15, the control unit CU may predict whether the road irregularity 20 would cause the vehicle to oscillate when passing over the road irregularity 20. Typically, there is a threshold movement of the front axle above which the control unit CU will decide that an oscillation that is prone to cause an oscillation has been detected.

[0050] Namely, the shown vehicle 1 is of a type with no suspension on the rear set of wheels 3, such that it may oscillate quite a lot when passing over an irregularity in the road.

[0051] If the control unit CU predicts that the road irregularity 20 will cause the vehicle to oscillate, it will control the actuator(s) 11 of the dump box 10 to tilt the dump box 10 to dampen the effect of the road irregularity 20 and to attenuate the predicted oscillation of the vehicle 1 .

[0052] Specifically, the dump box 10 is tilted at the moment when the rear set of wheels 3 passes over the road irregularity 20.

[0053] In order to correctly time the tilting of the dump box 10, the control unit CU may be configured to receive signals from a speedometer 19 regarding the current velocity v of the vehicle 1 and based on this current velocity v and the position of the detected road irregularity 20 the control unit CU may predict when the rear axle RA of the vehicle will pass over the road irregularity 20 and control the actuator (s) 11 to tilt the dump box 10 when the rear axle RA passes over the road irregularity 20.

[0054] Specifically, the actuator (s) 11 is / are controlled to tilt the dump box 10 upwards with respect to the pivot point PP when passing over a road irregularity 20 in the form of a bump on the road. Preferably, the dump box 10 is tilted upwards with respect to the pivot point PP when or after the rear set of wheels 3 passes the highest point of the bump. When the dump box 10 is tilted upwards the centre of gravity G of the dump box is elevated a height h with respect to its initial position.

[0055] In contrast, the dump box 10 is tilted downwards with respect to the pivot point PP, to lower the centre of gravity G of the dump box, when the vehicle passes over a road irregularity in the form of a hole in the road, and preferably the dump box 10 is tilted downwards at the moment when or after the rear set of wheels 3 passes over the lowest point of the hole. Thereby, the work W provided by the upward or downward moving of the dump box will compensate for the kinetic energy Ekupwards or downwards, respectively, created by the undampened impact between the rear set of wheels 3 and the road irregularity 20.

[0056] The work W may be calculated from the mass mbOx of the dump box, the height h by which the centre of gravity G of the dump box is elevated, and the acceleration a of the upward or downward movement according to the following formula:

[0057] W = mbox* h * a

[0058] The kinetic energy Ekupwards is dependent on the mass m of the vehicle and the upward velocity v according to the following formula:

[0059] Hence, in order to completely attenuate the oscillation, the work W provided by the upward moving of the dump box shall equal the kinetic energy Ekupwards created by the impact with the road irregularity 20.

[0060] The acceleration a provided by the actuation of the actuator(s) 11 will normally be sufficient to provide a dampening of most oscillations but not to achieve a complete attenuation of a more important oscillation. In most embodiments though, it may be sufficient to dampen the oscillation to a certain extent.

[0061] In other, more extreme embodiments, where a rapid actuation of the actuator(s) 11 and hence a more important acceleration a is desired, at least one hydraulic accumulator 18 may be arranged to rapidly actuate the actuator(s) and 11 move the dump box 10 upwards or downwards with respect to the pivot point PP.

[0062] The inventive method is helped by the fact that the dump box constitutes a major part of the total weight of the vehicle, often about two thirds of the total weight. In a specific embodiment the dump box constitutes about 8400 kg and the vehicle’s total weight of 12 900 kg. However, the invention would still work with a lighter dump box in view of that a similar effect could be achieved by a higher acceleration a of the dump box and / or an increased height h by which the centre of gravity G of the dump box is elevated.

[0063] As is illustrated in Fig. 3, the set of front wheels 2 are arranged on a suspension system 5 and the sensor 15 is arranged in the suspension system 5 to detect when the set of front wheels 2 are either pushed upwards or allowed to move downwards with respect to the suspension system 5.

[0064] Specifically, two sensors 15 may be arranged; one on a first dampening cylinder 12, and another on a second hydraulic dampening cylinder 13, wherein the first dampening cylinder 12 is arranged to dampen the left side of the front axle 6, and the second dampening cylinder 13 is arranged to dampen the right side of the front axle 6. The dampening cylinders are filled with a fluid, either a compressible fluid such as air or an incompressible fluid such as a hydraulic oil.

[0065] In the shown embodiment the fluid is an incompressible fluid and as is schematically illustrated in the embodiment in Fig. 3, two pressure tanks 17 are arranged, to which the fluid inside the dampening cylinders will be allowed to escape if pressurised to a pressure above the pressure inside the respective pressure tanks 17.

[0066] As an alternative, the sensor(s) may be arranged on the pressure tanks 17 and / or the lines between the dampening cylinders 12 and 13 and the pressure tanks 17. The object of the sensors in this specific embodiment is to monitor the dampening of the dampening cylinders 12 and 13, i.e. typically how much they have moved from their initial positions, so as to determine the magnitude of an irregularity 20 on the road.

[0067] A fork leg 14 arranged to the front axle 6 and is connected at a rotation point RP to the chassis 8 of the vehicle allowing the fork leg 14 to rotate around a rotation axis RA, extending in the longitudinal direction of the vehicle, orthogonally to the front and rear axes FA and RA, respectively.

[0068] Further, the front axle 6 is allowed to rotate around the rotation axis RA at an articulation point AP, typically comprising so called doglegs, which will allow the front axle 6 to rotate about the rotation axis RA and to move upwards or downwards, in order to enable upwards and downwards movement of the front axle 6 with respect to the chassis 8 of the vehicle. The first and second dampening cylinders 12 and 13, respectively, may be actuated to different levels depending on which side the road irregularity 20 is most prominent.

[0069] It should be noted that the arrangement with sensors 15 will discover a road irregularity 20 regardless of if it only affects one wheel or both wheels. When two sensors are used it will also be possible to distinguish between the two sides. Further, in view of that the dump box may be controlled by means of two different actuators 11 , typically in the form of two hydraulic cylinders, it may be possible to tilt the dump box in asymmetric manner so to achieve a more prominent dampening effect on one side by adjusting one actuator 11 of the dump box 10 more than the other one. Such an arrangement would however also call for an arrangement that allows the dump box to be slightly tilted sideways, which is normally not the case.

[0070] Also, in view of the stiffness of the rear axle, as is illustrated in Fig 4, it may be just as effective to only provide a symmetric actuation of the dump box, i.e. to actuate both hydraulic cylinders 11 to the same degree.

[0071] In the embodiment shown in Fig. 4, where the actuators 11 are comprised of hydraulic cylinders, accumulators 18 are arranged to provide a rapid addition of hydraulic fluid to the hydraulic cylinders in parallel to a conventional hydraulic fluid system (not illustrated in the drawings) for controlling the hydraulic cylinders.

[0072] The accumulators 18 may typically be arranged to deliver a flow of about 1 500 l / min. Thereby, prolongation of the hydraulic cylinder of about 50 mm, which corresponds to 1 .2 litres, may be achieved in 50 ms, which will provide an important acceleration of the dump box to effectively compensate any oscillation of the vehicle.

[0073] As is illustrated in Fig. 4, the rear axle 7 is stiffly arranged to the chassis 8 without a suspension system. When, the vehicle is driven with a load in the dump box the dampening provided by the rear tyres 3, which are of an oversized type, will be sufficient to provide a sufficiently bump free ride provided that the vehicle is driven at a sufficiently low speed.

[0074] In Fig. 5 three different curves representing oscillations in three different conditions are shown.

[0075] In the first curve (a) an oscillation caused by a road irregularity 20 is illustrated where the oscillations decreases over time but is very important in the first oscillations.

[0076] In the second curve (b) it is illustrated how an oscillation caused by a road irregularity 20 is attenuated by normal actuation of the hydraulic cylinders 11 of the dump box 10, in which it is clear that an attenuation is effectively achieved although the oscillation is still prominent for at least the first two oscillations. In the third curve (c) it is illustrated how an oscillation caused by a road irregularity 20 is attenuated by actuation of the hydraulic cylinders 11 of the dump box 10 by means of accumulators 21 , such that the oscillation is almost completely attenuated.

[0077] In view of the it will be difficult to time the tilting of the dump box, it will be almost impossible to completely attenuate a prominent oscillation. On the other hand, it will not be a problem to attenuate a major part of such an oscillation.

[0078] The dump box 10 is configured to be positioned in a level position when the vehicle is in motion, which level position allows the dump box to be tilted both upwards and downwards with respect to the pivot point PP. Above, the invention has been described with reference to specific embodiments. The invention is however not limited to these embodiments. It is obvious to a person skilled in the art that other embodiments are possible within the scope of the following claims.

Claims

CLAIMS1 . A method of controlling a vehicle (1 ) in motion, the vehicle comprising a dump box (10) that is configured to be actuated around a pivot point (PP) between a flat position and a tilted position by means of an actuator (11 ), the method comprising the steps of: monitoring by means of a sensor (15) a condition of a road on which the vehicle (1 ) travels, the sensor being configured to send signals regarding the monitored condition to a control unit (CU), when a road irregularity (20) is detected by the sensor (15), the control unit (CU) determining whether the road irregularity (20) is of a magnitude that will cause an oscillation of the vehicle (1 ) when passing over the road irregularity (20), if the control unit (CU) determines that the road irregularity (20) will cause an oscillation of the vehicle (1 ), tilting the dump box (10) to dampen the effect of the road irregularity (20) and to attenuate the oscillation of the vehicle (1 ).

2. The method according to claim 1 , wherein the vehicle (1 ) comprises a front set of wheels (2) and a rear set of wheels (3), the dump box (10) being tilted as the rear set of wheels (3) passes over the road irregularity (20).

3. The method according to claim 1 or 2, wherein the sensor (15) is arranged at the front set of wheels (2).

4. The method according to claim 1 , 2 or 3, wherein the control unit (CU) is configured to receive signals from the sensor (15) regarding the road irregularity (20) and from a speedometer (19) regarding a current velocity (v) of the vehicle (1 ) and to, based on the signals regarding the road irregularity (20) and current velocity (v) of the vehicle (1 ), determine when to tilt the dump box (10).

5. The method according to any one of the preceding claims wherein, when the detected road irregularity (20) is a bump on the road, tilting the dump box (10) upwards with respect to the pivot point (PP) when passing over the road irregularity (20).

6. The method according to claim 5, wherein the dump box (10) is tilted upwards with respect to the pivot point (PP) when or after the rear set of wheels (3) passes overthe highest point of the bump.

7. The method according to any one of the preceding claims wherein, when the detected road irregularity (20) is a hole in the road, tilting the dump box (10) downwards with respect to the pivot point (PP) when passing over the road irregularity (20).

8. The method according to claim 7, wherein the dump box (10) is tilted downwards when or after the rear set of wheels (3) passes the lowest point of the road irregularity (20).

9. An arrangement for controlling a vehicle (1) in motion, the vehicle comprising:- a set of front wheels (2) and a set of rear wheels (3),- a dump box (10) configured to be actuated around a pivot point (PP) between a flat position and a tilted position by means of an actuator (11), wherein the arrangement comprises: a sensor (15) for monitoring a condition of a road on which the vehicle (1 ) travels, a control unit (CU) configured to receive information regarding the monitored condition from the sensor (15) and to control the actuator (11 ) in response thereto, wherein in response to a road irregularity (20) being detected by the sensor (15), the control unit (CU) being configured to determine whether the road irregularity (20) will cause an oscillation of the vehicle (1 ) when passing over the road irregularity (20) and to control the actuator (11) to tilt the dump box (10) to dampen the effect of the road irregularity (20) and attenuate the oscillation of the vehicle (1)-10. The arrangement of claim 9 wherein the control unit (CU), when the detected road irregularity (20) is a bump on the road, is configured to control the actuator (11) to tilt the dump box (10) upwards with respect to the pivot point (PP) when the set of rear wheels (3) passes over the road irregularity (20).11 . The arrangement of claim 9 or 10 wherein the control unit (CU), when the detected road irregularity (20) is a hole in the road, is configured to control the actuator (11) to tilt the dump box (10) downwards with respect to the pivot point (PP) when the set of rear wheels (3) passes over the road irregularity (20).

12. The arrangement of any one of the claims 9 - 11 , wherein the sensor (15) is arranged at the set of front wheels (2) and arranged to detect when the set of front wheels (2) passes over the road irregularity (20), and wherein the control unit (CU) is configured to control the actuator (11) to tilt the dump box (10) with respect to the pivot point (PP) as the rear wheels (3) passes over the road irregularity (20).

13. The arrangement of claim 12, wherein the set of front wheels (2) include a suspension system (5) and wherein the sensor (15) is arranged in the suspension system (5) to detect when the set of front wheels (2) are either pushed upwards or allowed to move downwards with respect to the suspension system (5).

14. The arrangement according to any one of the claims 9 - 13, wherein the dump box(10) is configured to be positioned in a level position when the vehicle is in motion, which level position allows the dump box to be adjusted both upwards and downwards with respect to the pivot point (PP).

15. The arrangement according to any one of the claims 9- 14, wherein the actuator(11 ) is a hydraulic cylinder and wherein the arrangement (10) comprises at least one hydraulic accumulator (18) for rapidly actuating the hydraulic cylinder to rapidly move the dump box (10) upwards or downwards with respect to the pivot point (PP).

16. A vehicle (1 ) comprising an arrangement according to any one of the claims 9 - 15, the vehicle (1 ) having a tiltable dump box (10).

17. The vehicle (1 ) of claim 16, wherein the vehicle (1 ) is a heavy duty mobile underground mining vehicle.

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