Swivel loader

Abstract

The invention relates to a swivel loader with a vehicle frame and a loading arm which is pivotably mounted on the vehicle frame about a vertical axis by means of a swivel joint and which has a lifting boom pivotably mounted on a swivel joint via a horizontal swivel joint, an adjustable boom pivotally mounted on the same by means of an adjustable boom joint and a dipper arm pivotally mounted on the adjustable boom, wherein the adjustable boom and the dipper arm can be locked against each other in a longitudinal position to form a lifting arm for wheel loader operation.

Description

[0001] The present invention relates to a swivel loader with a vehicle frame and a loading arm which is pivotally mounted on the vehicle frame about a vertical axis by means of a swivel joint and which has a lifting boom pivotally mounted on a bogie of the swivel joint via a horizontal swivel joint, an adjustable boom pivotally mounted on the latter by means of an adjustable boom joint and a dipper arm pivotally mounted on the adjustable boom.

[0002] Such swivel loaders, with excavator-like loading arms, are used particularly in tight spaces. The tools mounted at the end of the dipper arm, for example, using a quick coupler, can be designed in different ways. A disadvantage is that swivel loaders with excavator-like loading arms are designed for a scraping, excavating motion from the tool to the vehicle frame. Therefore, the loading arm can only perform a limited number of typical tasks of a wheel loader equipped with a lifting arm, such as pushing or transporting small masses.

[0003] It is an object of the present invention to improve the field of application of a generic swing loader according to the above disadvantages.

[0004] The object is achieved by an object according to claim 1. Advantageous embodiments of the invention can be found in the subclaims and the following description.

[0005] According to the invention, the adjustable boom and the dipper arm can be locked against each other in a longitudinal position to form a lifting arm for wheel loader operation. This converts the swivel loader into a swivel wheel loader or allows switching between excavator-like swivel loader operation and wheel loader operation. By locking the adjustable boom and the dipper arm, the wheel loader's lifting arm is formed, allowing the use of tools typically used on a wheel loader, such as volume buckets or tines, which can be used to push or transport large masses.

[0006] According to the invention, the adjustable boom and the dipper arm are brought into a longitudinally stretched position relative to one another, in which the length of the lifting arm is essentially calculated by adding together the lengths of the adjustable boom and the dipper arm. The adjustable boom and the dipper arm can also run at an angle to one another, but form an angle of at least 135°. Both the length and the angle are calculated from a lateral view of the adjustable boom and dipper arm taken transversely to the vehicle's longitudinal axis or direction of travel, with the respective longitudinal extent being defined by straight lines between the respective pivot axes. In this case, the pivot axes of the lifting boom / adjustable boom on the one hand and the lifting boom / dipper arm on the other hand are used for the longitudinal extent of the adjustable boom, and the pivot axes of the adjustable boom / dipper arm and dipper arm / tool ​​orQuick coupler for the longitudinal extension of the dipper boom parked.

[0007] Horizontal swivel joints are joints with a swivel axis that is essentially horizontal and thus parallel to a horizontally running surface.

[0008] Preferably, the driver's cab or cockpit can be arranged laterally, i.e., transversely to the vehicle's longitudinal direction, on the vehicle frame for wheel loader operation and improved visibility past the loading arm. The pivot joint for the boom arm, comprising the lifting boom, the adjustable boom, and the dipper arm, is also directly mounted on the frame. For this purpose, the cockpit is arranged with a sliding frame, which represents a transversely movable part of the vehicle frame.

[0009] According to an advantageous development of the invention, in addition to the pivot joint for wheel loader operation, the lifting boom can be mechanically coupled to the vehicle frame in a coupling position of the lifting boom. In wheel loader operation, the lifting boom is thus coupled to the vehicle frame on the one hand via the pivot joint having a vertical pivot axis and on the other hand additionally mechanically connected to the vehicle frame, so that the lifting arm becomes part of the vehicle frame from a kinematic perspective for wheel loader operation via the adjustable boom joint and the additional mechanical coupling. Accordingly, the additional mechanical coupling is preferably spaced from the horizontal pivot joint at the other end of the lifting boom or in particular at least 30 cm, preferably at least 50 cm away from it in the vehicle's longitudinal direction.

[0010] The adjustable boom and dipper arm are locked against each other when they are designed to be immobile relative to each other during wheel loader operation, ie they form a single boom, particularly for a kinematic analysis.

[0011] In particular, in the coupled position, pivoting of the lift arm by means of the pivot joint, i.e. pivoting around a vertical pivot axis, is blocked, so that the pivot axes between the lifting boom and adjustable boom, as well as between the adjustable boom and dipper arm, run transversely to the vehicle's longitudinal axis and thus to the main direction of travel. Pivoting a tool located at the end of the lift arm around a vertical axis during wheel loader operation is therefore only achieved by the vehicle's steering. This can be implemented, in particular, by an articulated joint that connects a front and rear section of the vehicle frame. Alternatively or additionally, the swivel loader designed as a swivel wheel bearing can be equipped with an axle pivot steering system, in particular designed as an all-wheel pivot steering system.

[0012] Advantageously, pivoting of the lift arm is blocked in the coupled position, in particular, the lifting boom, which is moved into the coupled position by a rearward pivoting movement, rests against a side stop of the vehicle frame, thus supporting typical wheel loader operation of the front lift arm. The lift arm thus rests securely against the vehicle frame, which is also formed by the lifting boom during wheel loader operation.

[0013] Preferably, the lifting boom is secured in the coupled position to a bearing block of the vehicle frame by a locking mechanism, particularly extending transversely to the vehicle's longitudinal axis, wherein the bearing block in particular forms the aforementioned lateral stop. This ensures that the frontal forces generated during wheel loader operation are effectively transmitted into the vehicle frame. The bearing block can be sufficiently dimensioned to ensure the attachment or reception of the lifting boom and its locking. It extends upwards, in particular, from the further part of the vehicle frame, so that the lifting boom is secured in wheel loader operation, pointing diagonally upwards at the rear, starting from the pivot joint.

[0014] By attaching the adjustable boom to the dipper arm, as well as by attaching the lifting boom and integrating it into the vehicle frame, the frontal thrust forces generated during typical wheel loader operation are effectively absorbed and counteracted. It goes without saying that the dimensions of the dipper arm, adjustable boom, and lifting boom are sufficient for the resulting forces. The same applies to any actuators used to operate the respective booms. In particular, the lifting boom, adjustable boom, and dipper arm fold in a Z-shape and may fold into each other rather than side by side. This is detrimental to force transmission.

[0015] Preferably, the locking mechanism comprises at least one bolt with a bolt axis that runs at least partially transversely to the vehicle's longitudinal axis. This can be one or two bolts that can be moved transversely to the vehicle's longitudinal axis.

[0016] In particular, the locking action, for example, the actuation of the bolt from an open to a closed position to secure the lifting boom to the bearing block, is carried out by an associated actuator, which, for example, moves the bolt to the closed position, in which the adjustable boom is securely mounted on the bearing block. For example, the bolt(s) can be retracted and extended with a hydraulic cylinder or can be implemented simply and space-savingly using one or more piston rods of the hydraulic cylinder(s).

[0017] In particular, the actuator designed to operate the lifting boom is mounted at its vehicle-frame-side end in front of the pivot axis of the horizontal pivot joint, both to allow for rearward pivoting into the coupling position on the bearing block and to allow sufficient space for the bearing block itself. In particular, the actuator is mounted on the bogie of the pivot joint. Instead of a single actuator, several actuators can be provided to operate the lifting boom. This position is also advantageous for excavator operation of the lifting boom, when a hydraulic cylinder can be actuated across the entire surface of the cylinder head. This also applies to lifting large masses in wheel loader operation.

[0018] The operation of the lifting boom is further improved if the actuator designed to actuate the lifting boom is mounted at the end of a coupling rod mounted on the bogie of the swivel joint, the other end of which is attached to the lifting boom. The bearing point for the bogie is located between the bearing point for the lifting arm and the bearing point for the actuator, the latter preferably in the form of a cylinder. Such a rocker-like coupling can delay pivoting into a dead center and / or prevent impact on other components, and the overall pivot angle of the lifting boom is increased. This is particularly advantageous for transferring the lifting boom to the coupled position and for the pivoting movement of the adjustable boom during pivot loader operation. It goes without saying that the coupling rod is pivotably mounted on the lifting boom.During a transfer from the coupling position to a position for swing loader operation, the swivel axis at the vehicle frame-side end of the associated lifting cylinder of the lifting boom moves along a circular path.

[0019] Swing loader operation refers to the operation of the loading arm in excavator mode. In wheel loader mode, only the lift arm, i.e., part of the loading arm, is used.

[0020] Preferably, the adjustable boom and dipper arm can be locked against each other by means of at least one seat valve, thus using a structurally simple locking mechanism that forms a secure lock in the hydraulic circuit for controlling the actuators of the adjustable boom and dipper arm, typically formed by hydraulic cylinders, that withstands the forces occurring during wheel loader operation. Alternatively or additionally, the adjustable boom and dipper arm can also be mechanically locked against each other, for example, by using a bolt that locks the two parts of the lift arm against each other in the operating position for wheel loader operation.

[0021] Advantageously, a tilting mechanism decoupled from the vehicle frame is also provided for actuating a tool to be arranged at the end of the dipper arm boom, which significantly simplifies the design for swing loader operation. This can, in particular, be a linkage structure controlled by at least one hydraulic cylinder for tilting the tool or an associated quick coupler. In particular, this hydraulic cylinder can be actuated via a vehicle control system designed to hold the tool in a suitable position at the end of the dipper arm boom and, for example, automatically perform a corresponding alignment adjustment during raising of the lift arm or the adjustable boom.

[0022] To increase stability, a rear pendulum axle of the swing loader is designed to be lockable.

[0023] According to a further development of the invention, a front stop, particularly for the dipper arm boom, is provided for use in swing loader operation. This stop is formed by the swivel joint, in particular by a bogie of the same. In a rest position, the lift arm can then transfer part of the forces directly into the vehicle frame via the swivel joint, which ensures reduced load on the lift arm.

[0024] In particular, the vehicle frame can have a front and a rear carriage that are connected by an articulated joint, so that the swivel loader can imitate a classic wheel loader.

[0025] Alternatively or additionally, the swivel loader can be equipped with an axle steering system, particularly designed as an all-wheel steering system, so that, for example, crab steering is possible in swivel loader operation.

[0026] According to an advantageous development of the invention, the swing loader has a vehicle control system configured to vary the function of a joystick and / or at least one foot pedal depending on the wheel loader operation and / or the coupling position. For example, to switch to the swing loader mode or operation, the accelerator pedal can become the driving pedal, and the joystick can be assigned from excavator mode to wheel loader operation.

[0027] Further advantages and details of the invention can be found in the following description of the figures. Schematically shown: Fig. 1 a side view of an object according to the invention in a first operating position, Fig. 2 the object after Fig. 1 in another operating position, Fig. 3 the object after Fig. 1 with another tool and in another operating position, Fig. 4 the object after Fig. 3 shown with several superimposed operating positions, Fig. 5 a part of the object according to Fig. 1, Fig. 6 a sectional view of a part of the article according to Fig. 5, Fig. 7 the object after Fig. 1 in another operating position, Fig. 8 a detailed view of the object according to Fig. 1.

[0028] Individual technical features of the exemplary embodiments described below can also be combined with previously described exemplary embodiments as well as the features of the independent claim and any further claims to form subject matter according to the invention. Where appropriate, elements that are at least partially functionally equivalent are provided with identical reference numerals.

[0029] A swivel loader 2 according to the invention has a loading arm 3 and a vehicle frame 4 ( Fig. 1 and Fig. 4). In swivel loader operation, the loading arm 3 can be rotated about a vertical axis 6 by means of a swivel joint 5 (cf. Fig. 4 and Fig. 5). The swivel joint comprises a bogie 8, which forms the base of a horizontal swivel joint 10. A lifting boom 12 is mounted on the bogie 8 of the swivel joint 5 via the horizontal swivel joint 10, pivotable about a horizontal axis. Furthermore, an adjustable boom 16 is mounted on the lifting boom 12 by means of an adjustable boom joint 14. A dipper boom 18 is also mounted on this by means of a dipper boom joint 17, also pivotable about a horizontal axis. The other end of the dipper boom leads to a tool 20. This tool is arranged on the dipper boom 18 via a quick coupler 22.

[0030] To operate the tool 20 or the quick coupler 22, a tilting mechanism comprising a tilting link 24 and a tilting cylinder 26 is provided, which are arranged only on the dipper arm 18 or the quick coupler 22. The tilting mechanism is thus decoupled from the vehicle frame and can be operated independently of the adjustment or height guidance of the loading arm 3 (see Fig. 1, Fig. 2, Fig. 5, Fig. 6).

[0031] The adjustable boom 16 and the dipper arm boom 18 can be operated via hydraulic cylinders during excavation operation of the swing loader ( Fig. 3 and Fig. 4). For the design of a lifting arm of a wheel loader operation, the adjustable boom 16 and the dipper arm 18 are in the Fig. 1. This is achieved by blocking the stick cylinder 32, whose hydraulic circuit is blocked by a seat valve 33 shown only in dashed lines. Two lifting cylinders 36 are provided to the left and right of the adjustable boom 16 to actuate the lifting arm, which is essentially formed by the adjustable boom 16 and the dipper arm 18.

[0032] In addition to the relative fixation of the dipper arm 18 and the adjustable boom 16, the lifting boom 12 is also fixed to the vehicle frame via the horizontal pivot joint 10, the pivot joint 5 and an additional locking mechanism 38, and as such, when viewed as a lift arm, becomes part of the vehicle frame during wheel loader operation. For this purpose, a bearing block 40 is provided, which, as part of the vehicle frame 4, is generally arranged in front of a cockpit 42. This bearing block 40, which is fixed to the frame or vehicle frame, is also fixedly connected to at least one latch 44, which has a latch axis running transversely to the vehicle's longitudinal axis, which runs in the direction of travel F. The latch 44 can be moved, for example, by means of a lifting cylinder or manually, into the locking position, in which it is fixedly located on the bearing block and in a corresponding recess 46 in the lifting boom (see Fig. 4 and Fig. 5), transferable.

[0033] In this coupling position, in which the swivel loader 2 is in a wheel loader operating position, pivoting of the lifting arm 34 about both a horizontal and a vertical axis is blocked. For this purpose, the lifting arm is moved from the position shown in Fig. 4 (excavator operation) is moved backward into the coupling position. In this position, the lifting boom rests against a lateral stop 60 of the vehicle frame 4, which is formed by the bearing block 40, and is held by the latch 44.

[0034] Instead of directly engaging the side stop 60, the lifting boom can generally, in the various embodiments of the invention, engage the side stop formed by the upper end of the bearing block 40 with play and thus at a small distance, whereby pivoting of the lifting arm via the pivot joint is already blocked by the lock. In this case, engagement also includes being arranged close to the side stop. The pivot joint 5 generally allows pivoting only about the vertical axis.

[0035] In the operating position as a pure swing loader, the loading arm 3 is designed as an excavator arm and can Fig. 4 schematically shown positions during normal excavator operation. Here, the locking mechanism between the lifting boom 12 and the bearing block 40 is released. The loading arm 3 can be moved without the latch 44 from the position shown in the Fig. 3 shown position forward.

[0036] The boom cylinder 48 used to actuate the lifting boom 12 is mounted at its vehicle frame-side or bogie-side end 50 in front of the pivot axis of the horizontal pivot joint 10 with respect to the direction of travel F. In particular, the boom cylinder 48 designed to actuate the lifting boom is mounted at the end of a coupling rod 52 mounted on the bogie 8 of the pivot joint 5. The coupling rod 52 is arranged at the other end of the lifting boom 12, so that a coupling rod pivot axis 54 moves on a curved or circular path (in a side view). As a result, according to the Fig. 6 and Fig. 7 allows improved pivoting and force application to the lifting arm from the bogie 8. The Fig. 6 boom cylinder 48 shown extended or its piston rod 56 does not swing through the pivot axis of the horizontal pivot joint 10. In the Fig. The retracted position of the boom cylinder 48 shown in Figure 7 enables the relative to the Fig. 6 downwardly pivoted right end of the coupling rod 52 an increased pivoting of the lifting boom 12. In the excavator operating position according to Fig. 7 the loading arm 3 can therefore reach deeper.

[0037] For an improved design of a lifting arm 34 and its function, the bogie 8 is provided with a stop 58, which can additionally transmit any forces occurring on the dipper arm 18 during wheel loader operation into the vehicle frame 4 ( Fig. 8). The stop is the front stop in the direction of travel at the front end of the bogie 8.

[0038] Instead of a design with a front and a rear carriage, which is separated by a spacer between the wheels 60 (e.g. Fig.2), the swivel loader 2 designed as a swivel wheel loader is designed with an all-wheel steering system, according to which the wheels 60 can be transferred into a crab-steering position and can be positioned pivoted in the same direction to the vertical axis.

[0039] The swivel loader 2 according to the invention further comprises a vehicle control system implemented in a computer unit 60 (shown only in dashed lines). This control system includes, for example, a CAN bus, through which both a joystick 62 and a foot pedal 64 can be assigned different functions depending on whether the wheel loader is operating as a wheel loader or purely as a swivel loader. It is understood that the vehicle control system has and can implement corresponding commands for this purpose.

[0040] To increase stability, a rear pendulum axle 66 of the swivel loader 2 is designed to be lockable.

Claims

[1] A swivel loader with a vehicle frame (4) and a loading arm (3) which is pivotably mounted on the vehicle frame (4) about a vertical axis (6) by means of a swivel joint (5) and which has a lifting boom (12) pivotably mounted on a bogie (8) of the swivel joint (5) via a horizontal swivel joint (10), an adjustable boom (16) pivotably mounted on the latter by means of an adjustable boom joint (14), and a dipper arm boom (18) pivotably mounted on the adjustable boom (16), characterized by that the adjustable boom (16) and the dipper arm boom (18) can be locked against each other in a longitudinal position to form a lifting arm (34) of a wheel loader operation. [2] Swing loader according to claim 1, characterized by that the lifting boom (12) can be mechanically coupled to the vehicle frame (4) in addition to the swivel joint (5) in a coupling position for wheel loader operation. [3] Swing loader according to claim 2, characterized bythat in the coupling position, pivoting of the lifting arm (34) is blocked by means of the pivot joint (5), in particular wherein the lifting boom (12) transferred into the coupling position by a rear pivoting rests against a side stop (60) of the vehicle frame (4). [4] Swing loader according to claim 2 or 3, characterized by that the lifting boom (12) is fixed in the coupling position to a bearing block (40) of the vehicle frame by a locking device which runs in particular transversely to the vehicle's longitudinal axis. [5] Swing loader according to claim 4, characterized by that the locking device has at least one bolt (44) with a bolt axis running at least partially transversely to the longitudinal axis of the vehicle. [6] Swing loader according to one of the preceding claims, characterized by that an actuator designed to actuate the lifting boom (12) is mounted at its vehicle frame-side end (50) in front of the pivot axis of the horizontal pivot joint (10). [7] Swing loader according to one of the preceding claims, characterized by that the actuator designed to actuate the lifting boom (12) is mounted at the end of a coupling rod (52) mounted on a bogie of the swivel joint (5), which is fastened at the other end to the lifting boom (12). [8] Swing loader according to one of the preceding claims, characterized by that the adjustable and dipper arm (16, 18) can be locked against each other by means of at least one seat valve (33). [9] Swing loader according to one of the preceding claims, characterized by that the adjustable and dipper arm (16, 18) can be mechanically locked against each other. [10] Swing loader according to one of the preceding claims, characterized by a tilting mechanism decoupled from the vehicle frame for actuating a tool (20) to be arranged at the end of the dipper arm (18), in particular by means of a quick coupler (22). [11] Swing loader according to one of the preceding claims, characterized by that a particularly rear pendulum axle (66) is designed to be lockable. [12] Swing loader according to one of the preceding claims, characterized by that the swivel joint (10), in particular its bogie (8), forms a particularly front stop (58) for the dipper arm (18). [13] Swing loader according to one of the preceding claims, characterized by that the vehicle frame (4) has a front and a rear carriage which are connected by an articulated joint. [14] Swing loader according to one of the preceding claims, characterized by that the swivel loader (2) is provided with an axle steering system designed in particular as an all-wheel steering system. [15] Swing loader according to one of the preceding claims, characterized bya vehicle control which is designed to vary the function of a joystick (62) and / or at least one foot pedal (64) depending on the wheel loader operation and / or depending on the coupling position.

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