FI121705B - Procedure and system for stabilizing a vehicle - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a method for stabilizing a vehicle. The invention further relates to a system for stabilizing a vehicle. The invention still relates to a vehicle.

BACKGROUND OF THE INVENTION 10

Forest machines, especially harvesters, forwarders and combinations thereof, are typically equipped with two frame structures, a front frame and a rear frame, which are connected to one another via a joint. By means of the joint structure, the said bodies rotate relative to one another, for example at least about both the vertical axis of rotation and the horizontal axis of rotation. The rotary axes pass through the joint and the horizontal rotary axis is parallel to the longitudinal and driving directions of the forest machine. Circular movements allow the forest machine to be controlled and the forest machine to easily cross obstacles such as rocks, rocks and stumps. Forestry machines have a boom crane with a tool attached to the end, such as a grapple or harvester head.

For forwarders and articulated machines, the front frame is supported by, for example, a single pair of wheels, and has a cab and powertrain on it. A load compartment is located on the rear frame. The crane can be located g on either the front frame or the rear frame and is typically located between the cab ™ and the load. The crane may also be connected to the same rotating platform as the cab 9. For example, the rear frame carrying two swinging bogies with two wheels and the corresponding bogies can also be £ in the front frame instead of individual wheels.

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g For harvesters, for example, the front frame is supported by one pair of wheels and one

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£ The cab and crane are located on top. A 35 ° power source is placed on the rear frame. The crane is typically located in front of the cab and the crane may also be coupled to the same rotating platform as the cab. For example, the rear frame is supported by one pair of wheels.

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Typically, when the harvester is at a standstill while working with the crane, the frame joint is locked and rotation about the horizontal axis of rotation is prevented. Thanks to this 5, the trunks are supported by each other and the support forces provided by the wheels make the forestry machine more stable and prevent it from tipping over. Support forces are needed as the tool is used to handle heavy loads away from the forest machine. The locking is effected, for example, by applying pressure from the crane lifting cylinder to a locking or braking device whose operation 10 is based on locking teeth or brake pads which engage the brake disk.

When the forest machine starts and moves, the joint is typically released so that the trunks cannot support each other. When moving in the terrain 15, the soil is uneven and the stability of the forestry machine must be sufficient to prevent falls. Particularly in the case of a harvester, the risk of tipping the front frame increases if the crane is sideways as the forest machine moves. Forwarders, where the forwarder Matila is on the back and the crane is on the front, also have a higher risk. The risk of collapse is greatest when the crane reaches its maximum and the crane is oriented substantially perpendicular to the side.

Summary of the Invention The method of stabilizing a vehicle according to the invention is set forth in claim 1. The system of stabilizing a vehicle according to the invention is set forth in claim 7. The system of stabilizing the vehicle according to the invention is also disclosed in claim 11.

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The object of the invention is to improve the stability of forestry machines

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especially while driving. The invention reduces the risk of Nitro tipping over when moving a forest machine when the crane is

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£ away from the direction of travel and the tool is positioned laterally from the forest machine 35.

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By means of the invention, the wheels of the first frame form the support points and transmit the support forces through the joint to the second frame where the crane is. When crossing obstacles, the oscillations of the frame and crane are reduced as before, because the articulated pressure medium system stabilizes the frame. 5 The actuators of the articulated pressure medium system produce a torque to prevent rotation of the frames, which stabilizes the other frame.

A feature of the invention is to select a resistive torque such that it is dependent on the crane's rotational position. In particular, stability must be increased in a rotational position where the crane is substantially perpendicular to the longitudinal direction of the forest machine. The crane is typically secured to the body via a pivoting device. The pivoting device enables the crane to be pivoted about a vertical pivot axis. The turning device may also be a platform on which both the cab and the crane are mounted. Particularly in harvesters, the swivel and crane can also be tilted. The position of rotation of the crane can be determined, for example, by means of a sensor in the turning device.

An aspect of an embodiment of the invention is to select a resistive torque in addition to being dependent on the crane reach. The position of the crane joints or the position of the telescopic boom of the crane affect the reach of the crane and thus the distance of the tool from the forest machine. Stability must be increased as the distance increases with the working tool and the pivot axis of rotation, and especially when the crane is misaligned with the longitudinal direction of the forestry machine.

^ The reach of the crane can be determined, for example, by sensors in the crane joints or on the boom.

An embodiment of the invention is characterized by operation in conjunction with a crane lifting cylinder, wherein the pivot actuators receive Q_ the required pressure from the lifting cylinder, without a separate pump or pressure source. This also has the advantage of increasing the load on the crane

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the pressure is also correspondingly higher, so the resistive torque ™ 35 is correspondingly higher.

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Another embodiment of the invention is a joint-pressure lubricant system which, by simple control valve arrangements, is capable of providing a plurality of stabilizing moments. The lifting cylinder of the crane can be used as a source of pressure.

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Another embodiment of the invention is a joint pressure lubricant system which, by means of a pressure source and, for example, a proportionally acting valve, is capable of providing the desired stabilizing torque.

The invention provides advantages especially in forestry machines that move on uneven terrain. In particular, there is a harvester which is in motion and at the same time holds a heavy harvester head with a crane whose orientation is different from the longitudinal direction of the forestry machine.

The invention can also be applied to other vehicles which move on uneven ground or off-road and have chassis and crane connected to each other by a articulated joint. The invention can also improve the stability of these vehicles.

Cylinders according to prior art which lock and stiffen the joint if desired or allow the joint to function may also be utilized in the invention. One example of cylinders and joints is disclosed in WO 03/055735 A1.

25 Brief Description of the Drawings

The invention will now be described in more detail with reference to the accompanying drawings.

Fig. 1 shows a harvester in which the invention is applied.

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Fig. 2 shows a forwarder in which the invention is applied, m oo

Figure 3 is a plan view of the crane.

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Figure 4 illustrates a control system in which the principles of the invention are applied.

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Figure 5 illustrates a joint control circuit in which the principles of the invention are applied.

Figure 6 shows another joint control circuit in which the principles of the invention are applied.

DETAILED DESCRIPTION OF THE INVENTION Fig. 1 illustrates the application of the invention to a harvester comprising a frame 1 on which a cab 2 and a crane 3 are placed via a pivoting device 4, and a frame 5. The frames are connected to one another by a joint 6 about the vertical axis and the rotation of the bodies about the horizontal rotation axis X1. The axis of rotation X1 is substantially parallel to the driving direction and the longitudinal direction of the harvester. The orientation of the crane 3 and the angle of rotation A1, e.g. relative to the axis of rotation X1, are adjustable by means of the turning device 4. In Fig. 1, the rotation angle A1 is at a maximum 90 ° and ranges from 0 ° to 90 ° since the smallest angle between the crane 3 and the rotation axis X1 is always considered. The angle of rotation and its reference can also be selected from other straight, direction or point, and thus the angle of rotation can be, for example, between 0 ° and 360 °, depending on the equipment. As a reference for the horizontal gauge E1 of the crane 3, the vertical axis of rotation of the crane 3 or any other position in the pivoting device 4 can be selected, for example 25. The gauge E1 varies with the distance of tool 7 and the position

δ ^ In the situation of Fig. 1, the risk of overturning increases as the rotation angle A1 increases. When the joint 6 locks or forms an anti-rotation 30 frame, the body 1 is also able to rest, via the joint 6, on the inner wheel 8 of the £ body 5 between the wheel 8 and the ground Q.

stabilizes the forest machine.

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Figures 4 and 5 show in more detail one of the forestry machine joints 6 and the pressure medium circuit controlling it, the crane turning device 4 and the pressure medium circuit controlling it, and the operating principle of the control system.

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The joint 6 is illustrated by an outer ring 6a and an inner ring 6b which are mounted on one another and illustrate a peripheral bearing or similar construction. The outer ring 6a rotates with the structures of the body 1 and the inner ring 6b rotates with the structures of the body 5. The position of the outer ring 6a in relation to the body 1 and the inner ring 6b can be controlled by at least one, but usually two, pressure medium actuators 9 and 10. The actuators can be, for example, 2-acting cylinders, which are coupled to the joint so that the operation is symmetrical. The cylinders 9, 10 are on opposite sides of the hinge 6 and their increase in length rotates from the hinge 10 in opposite directions. In the terrain, trunks cross obstacles and rotate relative to each other, mechanically forcing the outer perimeter to change position. A pressure medium can be applied to each cylinder 9, 10 specifically for the purpose of applying a pressure in one or both cylinders which, relative to the rotation axis X1, exerts a force opposing the rotation of the articulation 6 and, in Figure 5, the inner periphery 6b.

The cylinders 9 and 10 are connected to the pressure source via means, e.g., control valves 11 and 12. The valves are, for example, 3-position 4-way valves, which are electrically controlled and centered by springs. Each of the valves 11 and 12 can be connected so-called. a float position (center valve position) with a free connection between the piston rod (CR) chamber of each cylinder and the piston chamber (CP). The cylinder and the joint 6 move freely during floating. By means of the valves, the pressure source 25 can alternately be connected to one chamber of the cylinder, the other chamber being connected via a valve to a return line or a tank line. The valve symbols shown in Figure 5, e.g., valves 11, 12,

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™ illustrate functions that can also be accomplished with a variety of individual valves. For example, flotation is achieved by a single ® 30 shut-off valve that connects the cylinder chambers, so valves 11, g 12 have a central position that closes all lines.

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g The anti-rotation torque of the joint 6 varies depending on the positions of the valves £ 11 and 12 according to Table 1. The magnitude of the torque and the direction of action indicated by the sign depend on which of the two chamber blades (CR, CP) of the pressure source is connected. The second chamber (CR, CP), in turn, is connected to a return line or a tank line.

7 __Cylinder 9__Cylinder 10__A moment

Case 1__weather__weather__0_

Case 2__CR__weather __- M1_

Case 3__weather__CR __ + M1_

Case 4__CP__weather __ + M2 (M2> M1)

Case 5__weather__CP __- M2 (M2> M1)

Case 6__CP__CR __ + M3 (M3> M2)

Case 7 CR | CP | - M3 (M3> M2)

table 1

As shown in Table 1, three pressure or torque levels are achieved which act on the joint 6 in both clockwise and anticlockwise rotation. The absolute magnitude of the pressure or torque level depends on the pressure of the pressure source and the dimensioning of the cylinders. Specifically, and since the actuator is a cylinder with a movable piston rod, it is a support force generated by the cy-10 cylinder under the action of the pressure medium. The resulting torque depends on e.g. 6 and the perpendicular distance of the thrust relative to the axis of rotation X1. Instead of the article, this article could talk about the aforementioned support force.

According to one example, the positions of the valves 11, 12 are selected based on the rotation angle A1 of the crane 3. The greater the angle of rotation A1, the greater the desired stabilizing torque. The angle of rotation A1 of the pivoting device 4 or the corresponding pivoting position is determined, for example, by the sensor 14 in the pivoting device 4. Figure 4 shows one

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^ 20 Hydraulic-mechanical pivoting device controlled by pressure medium and ° comprising toothed rails movable by hydraulic actuators 00 -1- which, via a toothed ring, move the body structure, which | on top of the crane is placed. The turning device can also act as a turning device for the cab if the cab and the crane are connected to the same structure.

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°° 25 fungus. The precise operation of the sensor 14 may vary and be based, e.g., on coding, pulse counting, variable resistance, or inductive operation. The position of the sensor 14 may differ from that shown and its operation may be based on various devices for which a signal dependent on the rotation angle A1 is available.

According to another example, the positions of the valves 11, 12 are additionally selected on the basis of the reach E1 of the crane 3. The greater the dimension E1, the greater the stabilizing torque is desired. The combined effect of the rotation angle A1 and the gauge E1 may be such that a torque corresponding to that of the large rotation angle A1 and the small gauge E1 is required for the small rotation angle A1 and the large gauge E1.

According to one example, the source of pressure is the lifting cylinder 13 of the crane 3, the position of which in the crane 3 is shown in more detail in Figure 3. The crane 3 typically comprises a column 15 mounted on a pivoting device 4, and a 17, which can operate telescopically. A tool may be attached to the transfer boom end 19. An actuator 13, which is controlled by pressure medium and is a 2-acting cylinder, is connected between the column 15 and the lifting boom 16. Between the lifting boom 16 20 and the transfer boom 17 is coupled an actuator 18 which is controlled by a pressure medium and which is a 2-acting cylinder. When the actuator 13 is connected as shown in Fig. 3, the weight of the lifting boom 16, the transfer boom 17 and the tool exerts pressure on the piston-side (CP) volume of the lifting cylinder 13, which can serve as a four source for cylinders 9, 10.

The advantage of using the lifting cylinder 13 as a source of pressure is that as the load on the tool increases, the stabilizing torque 9 automatically increases. Increasing the gauge E1 also automatically increases the pressure in the lifting cylinder '30 13.

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Alternatively or additionally, the cylinders 9, 10 may be connected to valves S 20, 21 to another source of pressure, e.g.

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£ to the hydraulic pump. The other control circuit 35 associated with the valves 20, 21 varies as required, and Figure 5 shows only one example where the valves 22, 23 can be used to separate the valves 20, 21 or from the lifting cylinder 13. The control circuits of the turning device 4 and lifting cylinder 13 are known per se. and vary as needed. The lifting cylinder 13 can, if necessary, be separated by valves 31, 32 from other sources of pressure when stabilization by the cylinders 9, 10 is applied.

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Alternatively, as shown in Figure 6, one or more cylinders in the hinge can be connected to one of the pressure sources P, for example, by a forestry machine hydraulic pump, by means of one or more other control valves. In the example of Figure 5, the valves 11,12 are interchangeable 10 with proportional actuators. In the example of Figure 6, the cylinders 9, 10 are in communication with a directional valve 34 having a closed center position, and further, the cylinders 9, 10 are connected in parallel. In the case of a proportional valve, the cylinder may also be single-acting. The directional valve 34 is usually preceded by an electronically controlled pressure relief valve. The Pai-15 source and control valve control the cylinder pressure level in a manner known per se. The pressure level, in turn, influences the prevailing support force.

Fig. 2 illustrates the application of the invention in a forwarder 20 comprising a load 29 in a frame 5 and a crane 3 in a frame 1. Otherwise, the part numbering corresponds to the harvester of Fig. 1.

The system is controlled by an electrical control unit 24, preferably software modifiable, which monitors the work machine and all auxiliary functions associated with it. In addition, the control unit 24 reports the operation of the machine on the cab display and various settings and adjustments can be stored in the system via the user interface 25. The control unit ^ 24 is typically complete on the machine and is programmed or modified to perform the desired functions, but the detailed modifications required will be readily apparent to those skilled in the art from this disclosure. The precise structure of the control unit will vary and will usually be distributed. wherein the various S functions of the control unit 24 are decentralized to a plurality of separate modules that discuss £ e.g. via a CAN bus (Controller Area Network) Based on the manually provided control values and input from the sensor elements, the control unit 24 provides e.g. The operation is based on a software-controlled control algorithm stored in one example, with a predetermined relationship between the rotation angle A1 and the stabilizing torque or support force. ma A1 corresponds to a specific pressure or control valve position.

5 Dependence can also be affected by the gauge E1 and / or the inclination. The control unit 24 may also be a module which is connected to another control system and in which the above control algorithm is implemented by simple logic.

The control unit 24 is defined, for example, by what kind of resistive torque is introduced as a function of the rotation angle A1. The rotation angle is obtained, for example, from sensor 14. The control valves or valve 34 are controlled accordingly. Table 2 shows the control of the valves 11 and 12. The sign in the example in Table 2 indicates either side of the forest-15 machine and the crane 3 is oriented relative to the axis of rotation X1. The direction of impact of the torque must be opposite to the tilt of the forestry machine.

__ Angle A1__ Torque

Case 1 __- α1 - + a1__0_

Case 2 __ + α1 - + a2 __- M1_

Case 3 __- α1 - -a2 __ + M1_

Case 4 __ + α2 - + a3 + M2 (M2> M1)

Case 5 __- α2 - -a3 __- M2 (M2> M1)

Case 6 + α3 - + α4 (+ 90 °) + M3 (M3> M2)

Case 7 -α3 --α4 (-90 °) | - M3 (M3> M2) o Table 2 C 1 - 20 ° The resistive moment increases linearly, progressively, or as shown in Table - 2 in increments of an angle. For example, angles determine | the crane 3 has several sector areas using a particular mo- tor. The size of the sectors and the size of the crane may vary

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In addition, the orientation may influence torque selection. Sector ranges can also be selected so that the rotation angle ranges from 0 ° to 180 ° and the maximum torque is taken when the crane is almost perpendicular to the rotation axis X1, the second highest torque is used when the crane points forward and the third maximum torque used when the crane is facing rearward.

According to one example, in addition, the crane 3 protrusion E1 acts on the chassis torque. In the example of Figure 3, the joints of the crane 3 have sensors 26 and 27 which transmit information about the position of the joints to the control unit 24, which simply calculates the gauge E1 based on the sensor signals and known dimensions and geometry of the crane. If the transfer boom 12 is telescopic, then, for example, a sensor 28 is needed which transmits information about the length of the transfer boom 12. As the gauge E1 grows, the torque is increased or the set limit values above the set limits are always added to the next value.

There are several means for determining the gauge E1, including linear sensors for cylinders 15, especially cylinders 13 and 18, positioning or distance measurement of the crane head 19, and CAN messages from the control unit 24.

According to one example, the pressure of the lifting cylinder 13, which can be measured simply by means of a pressure sensor, affects the selected torque 20. When the pressure increases, the torque is increased or the set limit values above the set limits are always added to the next value.

According to one example, the inclination of the body 1 also affects the selected torque. The inclination can be measured by a sensor, for example a tilt sensor 30 in a crane, frame or cab, which is e.g. an acceleration sensor. For example, the selected torque may be reduced, e.g. by one or more steps, if the crane 3 is facing away from the tilt direction (towards the top), and 30 if the crane 3 is also directed towards the g tilt (toward the lower slope). With this function, the stabilization adapts to the terrain as the forest machine slopes or crosses an obstacle.

According to one example, one or more factors, i.e. rotation angle A1, gauge E1, pressure or inclination of the lifting cylinder 13, influence the selection of the resistance torque, e.g., the positions of the valves 11, 12. For example, the required control algorithm can be constructed such that maximum torque 12 is only available when both the rotation angle A1 is at its maximum and the gauge E1 and / or the pressure of the lifting cylinder 13 is at its maximum. The control algorithm can also take into account the tilt. Further, it can be arranged that, for example, in the above-mentioned situation 5, the cylinders 9 and 10 are locked so that the joint cannot move. Locking is effected, for example, by valves closing the lines leading to the chambers (CP, CR). The calculation suitable for the control algorithm and the conditions used can be more precisely selected, for example, on the basis of an experiment and depending on which factors affect stability most. In addition, the position and rotation of the joint 6 may be taken into account by increasing the resistive torque and, if necessary, completely locking the joint. The runnability of the forestry machine must be maintained and locking the joint 6 must not be the only option.

The invention is not limited to the above examples but may be practiced within the scope of the appended claims. The above structures, systems, and components are just a few examples of the functionality of the invention. The invention may be implemented as part of a forest machine of the known tech-20 ankle and its control system.

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Claims (12)

A method of stabilizing a vehicle, said vehicle comprising at least a tonne: 5. a first chassis structure (1), on which a rotatable crane (3) has been connected; a second chassis construction (5); a hinge structure (6) which interconnects said chassis structures with each other and permits a change of their reciprocal pivot position, whereby they are rotated about at least one axis (X1) substantially parallel to the longitudinal direction of the vehicle; eating at least one actuator (9, 10) in the articulation structure, which maintains said reciprocal rotational position; and in which method: a support force is provided with said actuator (9, 10) which counteracts a change in said reciprocal rotational position; characterized in that in the method it is further: determined by means of the sensor (14) the rotational position of the crane about 20 a vertical rotary shaft (A1); ooh conducts pressure medium needed to maintain the supporting force, to said actuator (9, 10) depending on it, how big said rotational position (A1) of the crane is. 25 2. A method according to claim 1, characterized in that: the pressure medium necessary for maintaining the supporting force is received from a pressure source, which acts as an actuator (13) of the crane; ooh 5. leads said pressure medium to said actuator (9, 10). ώ 30 x 3. A method according to claim 1 or 2, characterized in that the greater the supporting force, the more the crane's rotational position (A1) deviates from S from said longitudinal direction. tn h- · o ° 35 Method according to any of claims 1-3, characterized in that: it is determined the slope of the first chassis structure (1); and guiding said pressure medium to said actuator (9, 10) also depending on it, how large said slope is, and / or on it, in which direction said slope is. Method according to any one of claims 1-4, characterized in that: the range (E1) of said crane is determined in the horizontal direction; and guides said pressure medium to said actuators (9, 10) also depending on it, how large said range is. Method according to any of claims 1-5, characterized in that two actuators (9, 10) are used, each of which comprises a chamber (CR) on the side of the piston rod and a chamber (CP) on the side of the piston ; and conducts said pressure medium in each actuator (9, 10) to one of 20 said chambers or to neither of said chambers. A system for stabilizing a vehicle, the vehicle comprising at least one: a first chassis structure (1), on which a rotatable crane (3) has been connected; a second chassis construction (5); - a link structure (6) which interconnects said chassis structures with each other and allows a change of their reciprocal position, whereby they are rotated about at least one axle line (X1) which is substantially parallel to the longitudinal direction of the vehicle 1; and "which system comprises at least: [o - an actuator (9, 10) of the articulated structure configured to maintain said reciprocal rotational position and a supporting force counteracting a change of said reciprocal rotational position; characterized in that the system further comprises: transducer (14) for determining the crank position (A1) of a vertical pivot shaft (A1); control valve means (11, 12, 34), with which pressure medium needed to maintain the supporting force can be directed to said actuators (9, 10); and a control unit (24) configured to control said control valve means depending on the size of said rotary position (A1). System according to claim 7, characterized in that the system further comprises: at least one actuator (13) of the crane, from which the pressure medium necessary for maintaining the supporting force can be received. 9. A system according to claim 7 or 8, characterized in that said control unit is configured to increase the supporting force the greater, the more the crane position (A1) deviates from said longitudinal direction. System according to any one of claims 7-9, characterized in that said vehicle is a forest machine, in particular a harvester and a power source harvester, or a harvester, a power source and a cargo space provided. 11. Vehicles comprising at least: 25. a first chassis structure (1), on which a rotatable crane (3) has been connected; - a second chassis construction (5); ™ - a link structure (6) which interconnects said chassis structures with each other and allows a change of oo their reciprocal position, whereby they are rotated about at least one x axis line (X1) substantially parallel to the longitudinal direction of the vehicle; S - at least one actuator (9, 10) for the articulated structure, which 00 is configured to maintain said reciprocal rotational position o and a supporting force which counteracts a change of said reciprocal rotational position; characterized in that the vehicle further comprises: transducer (14) for determining the crank position of rotation of a vertical pivot shaft (A1); control valve means (11, 12, 34), with which pressure medium needed to maintain the supporting force can be directed to said actuators (9, 10); and a control unit (24) configured to control said control valve means depending on the size of said rotary position (A1) of the crane. Vehicle according to claim 11, characterized in that the vehicle further comprises: at least one actuator (13) of the crane from which the pressure medium necessary for maintaining the supporting force can be received. δ (M δ i oo X and CL CD m oo m h- · o o {M