Loading vehicle with automatic exhaustion function and method thereof

Abstract

A loading vehicle is specified, comprising a mobile chassis (1), a lifting arm (3) which can be pivoted about a lifting arm rotation axis (6) relative to the chassis (1) by means of a lifting device (10) in such a way that the lifting arm (3) can be raised and lowered, a tool holder (4) which is provided at the end of the lifting arm (3) remote from the lifting arm rotation axis (6) and which can be pivoted about a tool holder rotation axis (8) relative to the lifting arm (3), and a rolling-in device for automatically rolling in the tool holder (4) relative to the lifting arm (3) during a lifting process of the lifting arm (3).

Description

[0001] The invention relates to a loading vehicle with automatic refilling function and a method therefor.

[0002] Loading vehicles are well known and can be designed as wheel loaders, telescopic wheel loaders, telehandlers, or skid steers, for example. They have a mobile chassis on which a loading system is carried. The loading system usually has a lifting arm – possibly made up of several parts – with an attachment attached to a tool holder at the end furthest from the vehicle. The attachment can be a loading shovel, a pallet fork, etc. The lifting arm, for example in the case of telehandlers or telehandlers, can be telescopic, so that several arm elements, but at least two, can be moved into one another to change the overall length of the lifting arm.

[0003] Various kinematics are known for loading systems, particularly lift arms, on wheel loaders or telescopic wheel loaders. In particular, one kinematics in the form of so-called parallel guidance is known, with which an attachment maintains its angular position relative to the surroundings when the loading system is raised, i.e. is guided parallel, without manual operator input. The operator only has to raise or lower the lifting arm of the loading system by controlling a lifting cylinder and otherwise does not have to make any further input. The tool and the tool holder supporting the tool on the loading system are moved parallel in space. This ensures that the load carried by the tool, e.g. bulk material in a loading bucket, can be moved reliably.

[0004] Fig. 1 shows a sectional side view of a front section of a loading vehicle known from the prior art.

[0005] The loading vehicle has a mobile chassis 1, which can be part of a front or rear carriage of the loading vehicle, for example. A loading system 2 with a lifting arm 3 is attached to the chassis 1. In the example shown, the lifting arm 3 is telescopic; however, the invention, which will be explained later, can be used equally with telescopic and non-telescopic lifting arms.

[0006] Attached to the end of the lifting arm 3 is a tool holder 4, which, in the example shown, supports a replaceable loading shovel 5 in a known manner. The lifting arm 3 can be pivoted about a lifting arm pivot axis 6 relative to the chassis 1 and can thus be raised and lowered.

[0007] The tool holder 4 is attached to a front end 7 of the lifting arm 3 and can be pivoted about a tool holder rotation axis 8 relative to the front end 7 and thus to the lifting arm 3.

[0008] The pivoting of the tool holder 4 relative to the lifting arm 3 is effected by a tilting cylinder 9, which can be controlled in particular by an operator with the aid of an operating element, e.g. a joystick.

[0009] The lifting and lowering of the lifting arm 3 is achieved by means of a lifting cylinder 10 which is pivoted between the chassis 1 and the fixed part of the lifting arm 3.

[0010] If the lifting arm 3 with the tool holder 4 and thus the loading shovel 5 is raised, i.e. pivoted about the lifting arm rotation axis 6, the loading shovel 5 would tilt with the movement of the lifting arm 3. This is undesirable during operation because it increases the risk that the load held in the loading shovel 5 will be spilled over the lifting arm 3. For this purpose, a parallel guide is provided, which is intended in particular to ensure parallel guidance of the tool holder 4 and thus the loading shovel 5.

[0011] As part of the parallel guide, a master cylinder 11 is provided, which is arranged essentially parallel to the lifting cylinder 10. To the extent that the lifting cylinder 10 causes the lifting arm 3 to be raised or lowered, hydraulic fluid is also displaced by the master cylinder 11. The master cylinder 11 is hydraulically coupled in a suitable manner to the tilting cylinder 9, so that the hydraulic fluid moved by the master cylinder 11 upon movement of the lifting arm 3 triggers a movement of the tilting cylinder 9. This movement of the tilting cylinder 9 causes the tool holder 4 to be pivoted about the front end 7 of the lifting arm 3 when the lifting arm 3 is raised, such that a parallel displacement in space can be achieved. Appropriate dimensioning of the master cylinder 11 to match the tilting cylinder 9 is, of course, a prerequisite and is known per se.

[0012] The hydraulic fluid is added to the tilt cylinder 9 only during the lifting and lowering movement of the lifting arm 3 to compensate for the parallel guidance and can be manually overridden by the operator at any time. The master cylinder 11 is thus kinematically and sized and articulated in such a way that it only displaces the required hydraulic fluid from its chambers—on the piston or piston rod side—depending on the lowering or lifting movement, thus supplying the tilt cylinder 9.

[0013] In another design, the parallel guidance can also be achieved with the aid of a purely electronic control system, which determines the respective necessary hydraulic control of the hydraulic cylinders, in particular the tilting cylinder 9, as a function of a lowering or lifting movement of the lifting arm 3 and effects this by controlling hydraulic valves.

[0014] Again, with a different design, a so-called Z-kinematics can be realized, which can later be further developed using Fig. 7 There, the kinematics are designed so that when the loading system (the lifting arm) is raised, an automatic parallel guidance is achieved, although this parallel guidance is not achieved exactly, but only approximately.

[0015] Due to structural conditions, particularly due to space limitations, it is often the case in practice that when the lifting arm 3 is lowered, the tool holder 4 and thus the loading shovel 5 cannot be completely "rolled in." Rolling in means that the tool holder 4 with the loading shovel 5 rotates around the tool holder rotation axis 8 (in Fig. 1 clockwise) upwards into the upright position, as shown in Fig. 1 Later, using Fig. 4, a rolled-out position of the tool holder 4 and loading shovel 5 is also shown. The rolling-in is intended to ensure that the load can be securely held and transported inside the loading shovel 5.

[0016] However, especially with telescopic lifting arms 3, there are space limitations which do not allow the tool holder 4 to be rolled in sufficiently with the loading shovel 5, at least in the lower, lowered area of ​​the lifting arm 3. Instead, the loading shovel 5 remains in a forward-tilted position, as in Fig. 1 recognizable.

[0017] In the Fig. 1 In the example shown, the lifting arm is lowered at an angle of 25° to the ground. A bucket base 5a is at an angle of 36° to the ground (horizontal).

[0018] Fig. 2 shows the example of Fig. 1 with partially raised lifting arm 3 and correspondingly parallel shifted tool holder 4 and loading shovel 5.

[0019] The angle of the bucket bottom 5a remains unchanged at 36° due to the parallel displacement, while the angle of the lifting arm to the horizontal has decreased to 15°.

[0020] While in the situation of Fig. 1 a further rolling in of the tool holder 4 and the loading shovel 5 would not be possible or only possible to a very limited extent due to space constraints, there is a situation in which Fig. 2 With the lifting arm 3 raised, the possibility of further rolling in the tool holder 4 is possible, as this situation provides more space for rolling in. However, due to the restrictions imposed by the parallel guide, the relative position of the tool holder 4 and the loading shovel 5 in space remains unchanged.

[0021] The operator has in the situation of Fig. 2 However, it is possible to increase and thus improve the rolling action by actively acting on and operating the tilting cylinder 9.

[0022] Fig. 3shows a state in which the tool holder 4 was pivoted with the loading shovel 5 and thus rolled up.

[0023] By rolling up the bucket base 5a, which was carried out by the operator via control command, the angle of the bucket base 5a could be Fig. 3 from 36° to 46°. The loading shovel 5 is thus more upright than in the Fig. 1 and 2 .

[0024] The rolling in of the tool holder 4 by the operator with the help of appropriate operating commands during the lifting process of the lifting arm 3 is also referred to in practice as "scooping".

[0025] Since in the lower area ( Fig. 1) only a small angle range is available for rolling in or re-scooping, can lead to problems when loading fine-grained goods such as grain and fertilizer in agriculture or, for example, gravel in the construction industry. Even if the operator completely rolls in the loading bucket 5 with the lifting arm 3 lowered, the loading bucket 5 is still slightly tilted forward, as shown in Fig. 1 This means that the front edge of the loading shovel 5 is at a lower level than the accumulated material inside the loading shovel 5.

[0026] If now, as in Fig. 2As shown, when the loading system is moved upwards with the lifting arm 3, the previously described parallel guidance makes work easier for the operator. However, the parallel guidance only maintains the current orientation, i.e., the position with the loading bucket 5 tilted forward. Therefore, due to the movement of the lifting arm 3 and possibly the movement of the loading vehicle, part of the loaded material often falls out of the loading bucket 5.

[0027] However, as soon as the lifting arm 3 is raised and the parallel guidance thus leads to a rolling movement of the loading shovel 5 relative to the lifting arm 3, the loading shovel 5 could be rolled in further to raise its front loading edge and thus prevent the load from falling out. However, as explained, this rolling movement must be manually controlled by the operator, which is often not done in practice.

[0028] In addition, it can be disadvantageous that the center of gravity of the load moves further away from the tipping edge of the loader (the front axle of chassis 1) when lifting the lifting arm 3 and the loading bucket 5. In this case, it would be advantageous if the center of gravity of the load could be shifted closer to chassis 1 to reduce the risk of tipping.

[0029] In addition, Fig. 4 the loading vehicle of the Figures 1 to 3 , but with the lifting arm 3 fully raised. In addition, the tool holder 4 with the loading shovel 5 is pivoted completely downward, i.e., rolled out. In the example shown, the lifting arm 3 is raised such that it forms an angle of 78° to the horizontal. The bucket base 5a of the loading shovel 5 is pivoted downward and forms an angle of 34° with the horizontal.

[0030] The invention is based on the object of providing a loading vehicle in which the risk of losing loaded cargo is reduced compared to the prior art. Furthermore, the center of gravity when lifting the loading shovel of a loaded loading vehicle is to be improved.

[0031] The object is achieved according to the invention by a loading vehicle having the features of claim 1. Advantageous embodiments are specified in the dependent claims. Furthermore, a method for achieving the object is specified.

[0032] A loading vehicle is specified, comprising a mobile chassis; comprising a lifting arm which can be pivoted relative to the chassis about a lifting arm rotation axis by means of a lifting device such that the lifting arm can be raised and lowered; comprising a tool holder which is provided at the end of the lifting arm remote from the lifting arm rotation axis and which can be pivoted relative to the lifting arm about a tool holder rotation axis; and comprising a rolling-in device for automatically rolling in the tool holder relative to the lifting arm during a lifting process of the lifting arm.

[0033] Suitable loading vehicles include wheel loaders, skid steer loaders, telescopic wheel loaders, or telehandlers. Such loading vehicles have a mobile chassis. The chassis can be essentially rigid and support at least two axles. At least one of the axles, or both if necessary, can be steerable. The chassis can also be divided into a front and rear carriage, which are connected via an articulated joint or a pivoting joint.

[0034] The lifting arm (also referred to and understood as the loading system) is attached to the chassis or is supported by the chassis. The lifting arm can also be telescopic, i.e., extendable. In this case, it has at least one telescopic and one non-telescopic section. The non-telescopic section can be pivotally attached to the chassis and support the telescopic section. With the help of appropriate hydraulic cylinders, the telescopic section can be extended and retracted relative to the non-telescopic section.

[0035] The tool holder can serve as a tool carrier and be designed, in particular, to carry attachments and tools. A loading shovel or a fork, such as a pallet fork or a fork attachment for picking up hay or manure, etc. (e.g., a so-called "crocodile jaw"), is particularly suitable as a tool.

[0036] The raising and lowering of the lift arm is to be understood with respect to the loading vehicle in its operating state, i.e., upright. Accordingly, the raising and lowering of the lift arm refers to a horizontal plane.

[0037] The rolling device is used to automatically roll in the tool holder. Rolling in means pivoting the tool holder around the tool holder's rotation axis relative to the lifting arm. The pivoting occurs in such a way that the upper angle, which can be defined with respect to a horizontal line on the upper side, between the tool holder and the lifting arm is reduced. If, for example, a loading shovel is carried by the tool holder, the upper opening of the loading shovel is pivoted upwards and towards the upper side of the lifting arm during rolling in. The opposite movement to rolling in is rolling out, during which the upper opening of the loading shovel is pivoted downwards in order to empty the load contained in the loading shovel.

[0038] The rolling-in device enables automatic rolling, i.e., without operator intervention. In particular, the rolling-in can occur continuously or in stages while the lift arm is being raised. The maximum possible rolling-in angle can be achieved in each case. The maximum possible rolling-in angle depends on the swivel or raised position of the lift arm and changes according to the structural conditions. With the help of the automatic rolling-in function, the maximum possible rolling-in angle can always be largely utilized to ensure that the top opening of the loading shovel is facing upwards. This prevents loads from falling out of the loading shovel, which was described above as a disadvantage of the prior art.

[0039] To trigger automatic retraction using the retraction device, it is advisable for the operator to fully retract the tool holder with the lift arm lowered using suitable control commands, e.g., using a joystick. The operator then only needs to activate the lifting function of the loading arm, whereby the further retraction movement, e.g., of the bucket attached to the tool holder, takes place automatically. The "manual" retraction of the tool holder, controlled by the operator, can therefore already have taken place long before the lift arm is raised. The operator then no longer needs to issue a command to retract. The automatic retraction then takes place when the lift arm is raised.

[0040] For example, the operator can drive into a pile of debris with the roll-in function activated (also known as the "re-scooping function"). They must then manually control the bucket to its maximum roll-in position. Once this has been achieved, the re-scooping function is activated, so that, for example, an electronic control system automatically causes the bucket to roll further when the boom is subsequently raised (manually).

[0041] The automatic rolling device and thus the rolling function or re-scooping function can also be deactivated if the operator does not want to use the function.

[0042] The rolling device and rolling function can be activated as soon as the operator brings the tool holder close to the maximum possible rolling position during the initial manual rolling process. A tolerance angle range of, for example, 5 or 10° can be defined here. If the tool holder, and thus the loading bucket, is within this tolerance range, this is interpreted as meaning that the operator desires the maximum possible rolling.

[0043] The rolling device can be designed to automatically roll in the tool holder while the lifting arm is raised from a position in which it is pivoted downwards by at least 5° relative to the horizontal. The lifting arm must therefore be tilted downwards accordingly. Only then does the subsequent automatic rolling make sense, for example, to securely hold the load in the loading bucket.

[0044] The rolling device can be designed to effect an automatic rolling-in process of the tool holder while the lifting arm is raised from a lower, ground-level position. A lower, ground-level position means that the lifting arm is in a ground-level angle range. The ground-level angle range can be defined between a lower angle, in which the lifting arm with the tool holder and an attachment carried by the tool holder is completely lowered to the ground, and an upper angle, in which the lifting arm is raised by a maximum of 5°, a maximum of 10°, a maximum of 20°, a maximum of 30°, or a maximum of 40° relative to the lower angle.

[0045] The position of the lifting arm close to the ground can be defined by a ground angle range, wherein the ground angle range is an angle range that the lifting arm assumes relative to the horizontal when the lifting arm is lowered such that the tool holder is on the ground, including a tolerance range of up to 10° or up to 20° or up to 30° or up to 40°.

[0046] The rolling device can have a control device configured to automatically roll up when the lifting arm is raised and when the tool holder is in the rolled-up position within a roll-up angle range. The control device can be part of a loader vehicle control system. Various solutions are available, such as an electrical or electronic solution or a combined mechanical-hydraulic solution, as explained later.

[0047] Accordingly, the rolling device is activated when the tool holder is already in the rolled-up position and the lifting arm is raised. The tool holder is then automatically rolled further, as far as possible, during the lifting process of the lifting arm.

[0048] The roll-in angle range refers to the tool holder being rolled up to a stop, plus a tolerance angle range of, for example, 5° or 10°. Therefore, it is not necessary for the tool holder to touch the stop directly. Rather, it can also be pivoted up to just before it.

[0049] An operating device may be provided for an operator to input a lifting command to raise the lifting arm, whereby the lifting arm can be raised when the lifting command is given. The operator can thus trigger the lifting of the lifting arm by issuing a corresponding lifting command via the operating device, e.g., a joystick.

[0050] The rolling-up device can comprise a lifting arm angle determining device for determining a pivoting position of the lifting arm, and a tool holder angle determining device for determining a pivoting position of the tool holder, wherein the control device can be designed to effect the automatic rolling-up when it is determined by the lifting arm angle determining device that the lifting arm is raised, and when it is determined by the tool holder angle determining device that the tool holder is in the rolled-up position in the rolling-up angle range.

[0051] Angle sensors, for example, are suitable as angle-determining devices, which can detect the respective swivel positions. The operating device can be implemented, for example, by a joystick, which is used for general operation of the loading vehicle and is already known as such. As already explained above, the term "rolled-in position" means that the tool holder is rolled in as far as possible, with a tolerance range of, for example, 5° or 10°. The tool holder can be rolled against a stop.

[0052] A parallel device can be provided between the lifting arm and the tool holder for guiding the tool holder parallel relative to the surroundings when the lifting arm is pivoted, wherein the rolling-in device can have an interruption device for interrupting the action of the parallel device and wherein the interruption device can be designed to act during the automatic rolling-in of the tool holder and to prevent a parallel displacement of the tool holder when the lifting arm is raised. In this way, a parallel guide of the tool holder can be achieved in order, for example, to prevent the angular position of a loading shovel from changing relative to the surroundings when the lifting arm is raised. The loading shovel serving as an attachment is then moved parallel in space so that the load carried by it is moved safely.

[0053] The rolling device can interrupt the action of the parallel device with the aid of the interruption device if parallel displacement is not appropriate and rolling is desired instead. The interruption device can be part of the control device.

[0054] The parallel device can be implemented as a "true" parallel guide. Alternatively, a so-called Z-kinematics is also possible.

[0055] The parallel device can interact with a so-called tilting device to enable parallel displacement.

[0056] For example, a tilting device can be provided for pivoting the tool holder relative to the lifting arm, which can be controlled by an operator. The tilting device can accordingly be suitable for changing the pivoting position of the tool holder and thus, for example, the loading shovel. This allows, for example, a filled loading shovel to be emptied by pivoting the loading shovel downward (rolling it out).

[0057] The tilting device can, for example, have a tilting cylinder. The operator can issue a roll-in command via the control device to activate the tilting device and thereby roll in the tool holder based on the operator command.

[0058] The roll-in device may include an override device for overriding the action of the tilting device during the lifting of the lifting cylinder when automatic roll-in is activated. The override can be achieved, for example, by locking the tilting device or by tilting it more strongly to achieve the additional roll-in effect.

[0059] The tilting device can have a tilting cylinder for pivoting the tool holder relative to the lifting arm, wherein the parallel device can have a master cylinder which can be operatively arranged between the chassis and the lifting arm in order to accommodate a pivoting movement of the lifting arm relative to the chassis, wherein at least one hydraulic chamber of the master cylinder can be in communication with a hydraulic chamber of the tilting cylinder, wherein the master cylinder can be designed to override the tilting cylinder in such a way that when the lifting arm is pivoted relative to the chassis, hydraulic fluid can be moved between the master cylinder and the tilting cylinder, and wherein the master cylinder can be dimensioned in such a way that the volume of hydraulic fluid moved between the master cylinder and the tilting cylinder during the pivoting of the lifting arm causes the tool holder to be displaced in parallel when the lifting arm is pivoted.With this arrangement, the parallel guidance described can be achieved.

[0060] The rolling-in device can be designed to influence the effect of the master cylinder if automatic rolling-in is to be effected, wherein the effect of the master cylinder can be influenced in such a way that the rolling-in movement of the tool holder is assisted by the tilting cylinder. For example, the rolling-in device can have access to a hydraulic valve that can be opened to drain the hydraulic fluid from the master cylinder, so that no parallel guidance of the tool holder occurs. With the hydraulic valve closed, however, the master cylinder would ensure the parallel guidance of the tool holder in cooperation with the tilting cylinder and the lifting cylinder. In this case, the master cylinder controls the tilting cylinder in such a way that rolling-in occurs, i.e. no parallel displacement.

[0061] A method for automatically rolling in a tool holder in a loading vehicle of the type described above is described, comprising the steps: Check whether the tool holder is within a roll-in angle range; check whether there is an operator command to raise the lifting arm; if the results of the checks carried out in the two previous steps are positive, the tool holder will automatically roll in while the lifting arm is raised.

[0062] When using this method, it can be advantageous if the lifting arm is positioned close to the ground or lowered relative to the horizontal to activate the roll-in or re-scooping function. Automatic roll-in is particularly advantageous in this case.

[0063] These and other advantages and features of the invention are explained in more detail below using examples with the aid of the accompanying figures. They show: Fig. 1 the front area of ​​a loading vehicle with rolled-up loading shovel in a partially sectioned side view; Fig. 2 the loading vehicle of Fig. 1 with raised lifting arm and parallel shifted loading shovel; Fig. 3 the loading vehicle of Fig. 2 , but with the loading shovel rolled up further; Fig. 4 the loading vehicle of the Figures 1 to 3 with raised lifting arm and rolled out loading shovel; Fig. 5 a view analogous to Fig. 1 with marking of certain angles, with a loading shovel as attachment tool; Fig. 6 a representation analogous to Figures 1 and 5 , with a pallet fork as an attachment and marking of certain angles; Fig. 7 a partial view of a loading vehicle with Z-kinematics; and Fig. 8 a flow chart explaining the process of the automatic roll-in function.

[0064] The Figures 1 to 4have already been described above in connection with the explanation of the prior art. However, they are also suitable for explaining the invention, so duplication of the figures is omitted. Regarding the reference numerals 1 to 11, reference is therefore made to the above description of the Figures 1 to 4 referred to.

[0065] In addition to the prior art, a lifting arm angle sensor 12 serving as a lifting arm angle determination device is provided in the area of ​​the lifting arm rotation axis 6. Furthermore, a tool holder angle sensor 13 serving as a tool holder angle determination device is provided in the area of ​​the tool holder rotation axis 8.

[0066] The two angle sensors 12, 13 can be used to determine the respective swivel angles of the respective components. The lift arm angle sensor 12 can be used to determine the swivel angle of the lift arm 3 relative to the chassis 1. The tool holder angle sensor 13 can be used to determine the swivel angle of the tool holder 4 and thus of the loading shovel 5 relative to the end of the lift arm 3.

[0067] With the aid of the angle sensors 12, 13, it is possible for the system, in particular a rolling device according to the invention, for example integrated into a vehicle control system, to check whether the lifting arm or the corresponding loading system is in a lower position and whether the attachment tool (e.g. loading shovel 5) or the tool holder 4 is completely rolled up, wherein a tolerance range of 5° or 10° deviation of the maximum rolling up can be provided.

[0068] If the rolling device determines that these conditions are met, the re-scooping function (automatic rolling in) is activated, so that with the help of a control system not shown, e.g. an electronic control system of the loading vehicle (vehicle control), the tool holder 4 and thus the loading shovel 5 are automatically rolled in when the lifting arm 3 is subsequently raised manually using an operator command. The operator therefore only has to roll in the loading shovel 5 using a control command at or before the start of the loading process, e.g. before driving into a pile of material. If the operator subsequently raises the lifting arm 3 with a further control command, the loading shovel 5 will be rolled in continuously or step by step, as far as the structural conditions allow. The operator therefore only has to control the lifting function of the lifting arm 3. The rolling in movement of the loading shovel 5 takes place automatically.

[0069] In Fig. 1 A hydraulic parallel guide is shown, the functioning of which has already been explained above in connection with the prior art. According to the invention, this known hydraulic parallel guide is coupled to the rolling device to implement the automatic rolling function. However, the invention can also be implemented with lifting arm kinematics that do not have a parallel guide. The parallel guide is therefore not a mandatory component of the invention, but merely an advantageous variant.

[0070] For this purpose, a hydraulic valve can be provided between the tilt cylinder 9 and the master cylinder 11, which can be controlled by the controller when the roll-in function or re-scooping function is activated. For example, the valve can be opened to divert a portion of the hydraulic fluid originating or delivered by the master cylinder 11 and prevent it from entering the tilt cylinder 9. This reduces the deflection of the tilt cylinder 9, so that the parallel guidance of the tool holder 4 and the loading shovel 5 is reduced or even eliminated. Accordingly, the tool holder 4 can be rolled in more deeply.

[0071] In an alternative design, an electronic parallel guidance can be implemented in which the parallel guidance is not carried out with the aid of a master cylinder 11 in cooperation with the tilting cylinder 9, but exclusively by controlling the tilting cylinder 9 based on angle determinations with the aid of the angle sensors 12, 13. In this case, the electronic control can control the tilting cylinder 9 in such a way that maximum rolling in is always achieved when the rolling in function is activated.

[0072] When the lifting arm 3 has been positioned at a defined lifting arm position, the rolling-in function or re-scooping function can be automatically deactivated, so that the tool holder 4 with the attachment (loading bucket 5) maintains the rolled-in position throughout the remaining lifting range. For example, the limit for deactivating the automatic rolling-in function can be the horizontal position of the lifting arm 3, i.e., a horizontal position relative to a horizontal plane. This is intended to prevent the loading bucket 5 from being rolled in excessively and dumping load material over the lifting arm 3.

[0073] Fig. 2 shows, as already explained above, the position of the loading shovel 5 after the lifting arm 3 has been raised by 10°, but without automatic re-scooping function.

[0074] Fig. 3shows the position of loading bucket 5 after the lifting arm 3 has been raised by 10°, but with automatic re-scooping. The loading bucket 5 has been rolled in by 10° (angle 46° from the horizontal) compared to position 2 (angle 36° to the horizontal).

[0075] The Figures 5 and 6 show a comparison of the loading vehicle with different attachments on the tool holder 4. When displaying Fig. 5 the loading shovel 5, which has already been described several times, is held by the tool holder 4, at Fig. 6 Instead of the loading shovel 5, a pallet fork 14 is carried on the tool holder 4.

[0076] While the arrangement of Fig. 5 It is desirable to implement the automatic roll-up function, however, it is more advantageous when arranging Fig. 6 undesirable, as this would lead to an excessive inclination of the pallet fork 14.

[0077] To distinguish between these two cases, no special precautions are required. Rather, it is sufficient to appropriately evaluate the angle values ​​detected by the lifting arm angle sensor 12 and the tool holder angle sensor 13.

[0078] So in Fig. 5 It can be seen that the tool holder 4 has already been pivoted relatively far backward (large angle alpha - delta). This angular position is detected by the tool holder angle sensor 13.

[0079] In contrast, the arrangement of Fig. 6 the comparable angle of the tool holder 4 relative to the lifting arm 3 is considerably smaller (angle Beta - Delta).

[0080] The control system can accordingly detect, based on the angles detected by the tool holder angle sensor 13, that the tool holder 4 should actually be rolled in automatically ( Fig. 5 , large angle Alfa - Delta), while in the arrangement of Fig. 6Due to the small angle Beta - Delta, no curling should occur. Accordingly, the arrangement of Fig. 6 There is also no automatic rolling up when lifting the lifting arm 3.

[0081] Fig. 7 shows an alternative example to the previously shown kinematics with telescopic lifting arm 3.

[0082] At Fig. 7 the lifting arm 3 is not telescopic, but rigid, and can be pivoted about the lifting arm rotation axis 6 due to the action of the lifting cylinder 10.

[0083] The tilting of the tool holder 4 around the tool holder rotation axis 8 is performed in a conventional manner using a Z-kinematics 15. For this purpose, the tilting cylinder 9 can be actuated, the movement of which is transmitted to the tool holder 4 via the Z-kinematics 15.

[0084] With the help of the Z-kinematics 15, a parallel guide for the loading shovel 5 can be approximated, which may be sufficient in practice. The parallel guide is achieved by selecting the length ratios and pivot points of the guide rods and joints within the Z-kinematics 15.

[0085] By appropriately controlling the tilting cylinder 9 with the aid of the electronic control, automatic rolling in can be achieved in the manner described above.

[0086] Fig. 8 shows a simplified flow chart for automatic rolling or scooping.

[0087] First, a check is performed to determine whether the re-scooping function is activated. The re-scooping function can be activated by lowering the lifting arm 3 and rolling the tool holder 4 to its maximum. Subsequently, a corresponding check is performed to determine whether the tool holder 4 is within a permissible angle range, i.e., whether the tool holder is rolled to its maximum, taking into account a tolerance range of, for example, 5° or 10°.

[0088] The operator can then issue the "Raise arm" command without simultaneously rolling or extending the loading bucket 5 using another control command. In this case, the automatic re-scooping function is executed while the arm is being raised, as long as the operator inputs are met and the arm is not yet stationary (termination of the "Raise arm" command) or the arm is in the maximum horizontal position (horizontal).

Claims

1. Loading vehicle, with - a mobile chassis (1); - a lifting arm (3) which can be pivoted about a lifting arm rotation axis (6) relative to the chassis (1) by means of a lifting device (10), such that the lifting arm (3) can be raised and lowered; - a tool holder (4) which is provided at the end of the lifting arm (3) remote from the lifting arm rotation axis (6) and which can be pivoted about a tool holder rotation axis (8) relative to the lifting arm (3); and with - a rolling-in device for automatically rolling in the tool holder (4) relative to the lifting arm (3) during a lifting process of the lifting arm (3).

2. Loading vehicle according to claim 1, wherein the rolling-in device is designed to effect an automatic rolling-in process of the tool holder (4) while the lifting arm (3) is raised from a position in which it is pivoted downwards by at least 5 degrees relative to a horizontal.

3. Loading vehicle according to one of the preceding claims, wherein the rolling-in device comprises a control device configured to effect automatic rolling-in when + the lifting arm (3) is raised; and when + the tool holder (4) is in a rolled-in position within a rolling-in angle range.

4. Loading vehicle according to one of the preceding claims, wherein - an operating device is provided for inputting a lifting command by an operator to raise the lifting arm (3); and wherein - the lifting arm (3) is raised when the lifting command is present.

5. Loading vehicle according to one of the preceding claims, wherein the rolling-in device comprises - a lifting arm angle determination device (12) for determining a pivot position of the lifting arm (3); and - a tool holder angle determination device (13) for determining a pivot position of the tool holder (4); wherein the control device is designed to effect automatic rolling-in when + it is determined by the lifting arm angle determination device (12) that the lifting arm (3) is raised; and + when + it is determined by the tool holder angle determination device (13) that the tool holder (4) is in the rolled-in position within the rolling-in angle range.

6. Loading vehicle according to one of the preceding claims, wherein - a parallel device (11) is provided between the lifting arm (3) and the tool holder (4), for guiding the tool holder parallel relative to the surroundings when the lifting arm (3) is pivoted; - the rolling-in device has an interruption device for interrupting the action of the parallel device (11); and wherein - the interruption device is designed to act during the automatic rolling-in of the tool holder (4) and to prevent a parallel displacement of the tool holder (4) when the lifting arm (3) is raised.

7. Loading vehicle according to one of the preceding claims, wherein - a tilting device (9) is provided for pivoting the tool holder (4) relative to the lifting arm (3); and wherein - the tilting device (9) can be controlled by an operator.

8. Loading vehicle according to one of the preceding claims, wherein the rolling device has an override device for overriding the action of the tipping device (9) during the raising of the lifting arm (3) when the automatic rolling is activated.

9. Loading vehicle according to one of the preceding claims, wherein - the tipping device has a tipping cylinder (9) for pivoting the tool holder (4) relative to the lifting arm (3); - the parallel device has a master cylinder (11) arranged between the chassis (1) and the lifting arm (3); - at least one hydraulic chamber of the master cylinder (11) communicates with a hydraulic chamber of the tipping cylinder (9); - the master cylinder (11) is designed to override the tipping cylinder (9) such that when the lifting arm (3) is pivoted relative to the chassis (1), hydraulic fluid can be moved between the master cylinder (11) and the tipping cylinder (9); and wherein - the master cylinder (11) is dimensioned such that the hydraulic fluid volume moved between the master cylinder (11) and the tilting cylinder (9) during pivoting of the lifting arm (3) causes the tool holder (4) to be displaced in parallel when the lifting arm (3) is pivoted.

10. Loading vehicle according to claim 9, wherein - the rolling-in device is designed to influence the action of the master cylinder (11) when automatic rolling-in is to be effected; and wherein - the effect of the master cylinder (11) is influenced in such a way that the rolling-in movement of the tool holder (4) is assisted by the tilting cylinder (9).

11. A method for automatically rolling in a tool holder in a loading vehicle according to one of the preceding claims, comprising the steps of - checking whether the tool holder (4) is located within a rolling-in angle range; - checking whether an operator command is present to raise the lifting arm (3); - if the result of the checks carried out in the two preceding steps is positive, automatically rolling in the tool holder (4) while the lifting arm (4) is raised.

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