Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
  • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
  • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
  • E02F3/432—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like for keeping the bucket in a predetermined position or attitude

Definitions

• the invention relates to a control arrangement for a mobile working device, in particular a wheel loader or a backhoe loader, according to the preamble of patent claim 1.
• a boom is pivotably linked to a frame.
• the boom can be pivoted using an AUL boom cylinder supported on the frame.
• a bucket is mounted on the end section of the boom that is distant from the frame and can be pivoted via a bucket cylinder.
• Both cylinders are designed as differential cylinders and are connected to a variable displacement pump or a tank by means of a pilot control unit with an assigned proportional valve for retraction and extension.
• the boom and the bucket are to be controlled separately from one another by actuating a control lever of their control device.
• the control levers of the pilot devices are locked in their end position so that the blade assumes a predetermined relative orientation.
• a disadvantage of this solution is that the driver has to operate both pilot control devices in order to carry out the locking or to release the locking in order to raise the boom again. Furthermore is disadvantageous that both control levers must be designed with locks.
• the object of the invention is to provide a control arrangement for an implement, in particular a wheel loader or an excavator bearing, which is simplified
• the control arrangement has a valve arrangement which is connected to a control line of a boom control unit and to a signal line of a bucket control unit, so that the bucket can be transferred to a desired position via a control pressure of the boom control unit which is effective in the direction of lowering the boom.
• the control arrangement for lowering the boom can thus be passed on to the bucket control unit by means of the valve arrangement, so that a pre-control device of the bucket control unit does not have to be operated by hand.
• the ProportionaXvalve of the bucket control unit is then controlled via the control pressure output by the boom control unit.
• a control lever of the pilot control device of the blade control unit thus remains in its neutral position and is not locked in its corresponding end position.
• Control pressures in the signal line or the control line are fed to the proportional valve of the bucket control unit.
• the shuttle valve has two inputs to the
• the valve arrangement has a switching valve that is preloaded in the basic position.
• the switching valve can be switched to a switching position by means of a switching magnet which can be energized in an electric circuit via an activation switch.
• a position switch is advantageously arranged in the circuit, which interrupts it as soon as the blade has assumed its desired position. As a result of this interruption, the switching valve is returned to its basic position, so that the control pressure of the boom control unit effective in the lowering direction is not passed on to the bucket control unit.
• an end position lock is provided for locking a control lever of the pilot device of the boom control unit in its end positions.
• FIG. 1 shows a diagram of a control arrangement according to the invention with a work tool shown in simplified form
• FIG. 2 shows the control arrangement according to the invention according to FIG. 1 in a single view.
• FIG. 1 shows a diagram of a control arrangement of a mobile working device, for example a wheel loader or a backhoe loader.
• This has a boom 2, which is articulated with an end portion on a frame 4.
• a bucket 6 is pivotably mounted on the end section of the boom 2 which is remote from the frame 4.
• the boom 2 and the Scha ⁇ ifel 6 can be pivoted via a boom cylinder 8 or a Schaufeizylinder 10.
• the boom cylinder 8 is supported on the frame 4 and engages the boom 2 with a piston rod 32.
• the bucket cylinder 10 is supported on the boom 2 aib and engages the bucket 6 with a piston rod 34. Both cylinders 8, 10 are designed as double-acting cylinders.
• the pressure medium supply to the cylinders 8, 10 takes place in each case via a control unit 12, 14.
• the control units 12, 14 are constructed similarly and each have a pilot control device 16, 18 with a control lever 20, 22, which is connected via control lines 38, 40 or signal lines 42, 44 communicates with control rooms 46, 48 and 50, 52 of a proportional valve 24, 26.
• the proportional valves 24, 26 are spring-biased in the direction of a neutral position, in which all connections of the control units 12, 14 are blocked off from a feed pump or a tank.
• a control oil pressure provided by a control oil pump is reduced to a control pressure and passed to the proportional valves 24, 26, which are shifted from their neutral position in accordance with the actuation of the control levers and thus the boom 2 or the bucket 6 are actuated accordingly .
• the cylinders 8, 10, control units 12, 14, pilot control devices 16, 18, control levers 20, 22 and proportional valves 24, 26 are hereinafter referred to as boom arm or bucket assignment, boom cylinder 8, bucket cylinder 10, boom control unit 12, bucket control unit 14, boom pre-control device 16, bucket pilot device 18, boom control lever 20, bucket control lever 22, boom proportional valve 24 and bucket proportional valve 26.
• the boom proportional valve 24 can assume four positions for moving the boom 2 into a corresponding operating state.
• the possible positions are lifting (lifting), lowering (low), swimming (float) and holding (neutral).
• the piston rod 32 of the boom cylinder 8 extends and the boom 2 is pivoted counterclockwise.
• the piston rod 32 retracts and the boom 2 is pivoted clockwise.
• the piston rod 32 also retracts, but the pressure chambers of the boom cylinder 8 are connected to the tank, so that the boom 2 is brought into a floating state in which it rests on the ground in a manner that allows it to swing freely.
• Such a floating state of the boom 2 is set, for example, for leveling the subsoil, in which the shovel is pulled or pushed over the ground when the implement is being driven, and unevenness can thus be eliminated.
• the boom 2 In the neutral division, the boom 2 can be in a certain relative orientation
• the bucket proportional valve 24 can have three components
• Positions are tipping (dump), picking up (crowd) and Hold (Neutral).
• the piston rod 34 of the bucket cylinder 10 extends, so that the bucket 6 swivels clockwise and can tip over things picked up.
• the piston rod 34 retracts, so that the blade pivots counterclockwise and can pick up things.
• the blade 6 can be held in a specific orientation relative to the boom 2.
• the shovel 6 While the boom 2 is in the floating state, the shovel 6 is preferably transferred to a desired position in which it is set in a certain angular position relative to the boom 6. In this desired position, the blade 6 is spaced apart from the substrate with its blade edge 36 in order to prevent the substrate from being irritated.
• This target position thus corresponds primarily to a position of the blade 6 in which it is pivoted in counterclockwise.
• the boom control unit 12 and the bucket control unit 14 are connected to one another via a valve arrangement 28 according to the invention, so that a control signal of the boom control unit 12 acting in the direction of a lowering can be passed to the bucket proportional valve 26.
• the valve arrangement 28 has a switching valve 54 which is arranged between a boom connection line 30 and a bucket connection line 58.
• the boom connection line 30 is connected to the control line 40, which acts in the direction of lowering the boom 2.
• the blade connecting line 58 extends in the direction of the signal line 44, which in the direction of the desired position the blade 6 is effective.
• the blade connecting line 58 and the signal line 44 are connected to the inputs of a shuttle valve 60, the output of which is connected to the control chamber 52.
• the valve arrangement 28 For transferring the switching valve 54 into its switching position, in which the control pressure in the control line 40 can act on the blade proportional valve 26 via the shuttle valve 60, the valve arrangement 28 also has a circuit 62 through which a switching magnet 56 of the switching valve 54 can be energized.
• a current source 64, an activation switch 66 and a position transmitter 68 are arranged in the circuit 62.
• the activation switch 66 and the position transmitter 68 are spring-biased in the opening direction and connected in series, so that the switching magnet 54 can only be energized and the spring force of the biasing spring of the switching valve 54 can be overcome if the activation switch 66 and the position transmitter 68 are closed or actuated simultaneously.
• the activation switch 66 is actuated by the driver when the bucket 6 is to be moved into its desired position. It is preferably designed in such a way that it returns from its closed actuation position initiated by the driver to its open position as soon as the circuit 64 is interrupted. Manual resetting of the activation switch 66 is, however, also conceivable.
• the position sensor 68 is actuated directly or indirectly by the bucket 6 as a function of its momentary pivoting or relative orientation to the boom 6. It is closed until the blade 6 has assumed its target position. If the desired position is reached, the position transmitter 68 opens and the circuit 62 is interrupted. The circuit 62 is closed again when the blade 6 moves out of this desired position.
• FIG. 2 also shows that the boom precontrol device 12 has an end position lock 70 with an electromagnet 72 and a holding element 74.
• the holding element 74 is held on the electromagnet 72 by a magnetic force, so that the boom control lever 20 is secured in its position.
• the unlocking can take place automatically by switching off the electromagnet 72.
• the shovel 6 is to be brought into its corresponding desired position. This means, that the blade 6 is to be pivoted in counterclockwise, so that when the surface contacts the blade 6, the blade edge 36 is spaced apart from it and digging of the blade 2 is prevented.
• the driver actuates the activation switch 66 and the circuit 62 is closed, so that the switching magnet 56 is energized and the switching valve 54 is brought from its basic position into its switching position.
• the boom connection line 30 and the bucket connection line 58 are connected to one another and a control pressure of the boom control unit 12 which is effective in the direction of lowering can be led to the bucket proportional valve 26.
• This control pressure is generated by the driver pivoting the boom control lever 20 accordingly.
• a hydraulic control signal is generated by the boom pre-control unit 16, so that the control rooms 46, 48 are acted upon by a corresponding control pressure difference.
• the boom proportional valve 24 is brought out of its neutral division into its right position, so that the boom 2 is pivoted clockwise and brought into its floating state.
• the boom control lever 20 is locked in its end position by the end position lock 70.
• this control pressure is fed via the connecting lines 30, 58 and the shuttle valve 60 into the control chamber 52 of the vane proportional valve 26, so that a control pressure difference is generated between the control chambers 50, 52, by means of which the vane proportional valve 26 is moved to the left into its receiving division.
• the Bucket control lever 22 remains unactuated throughout the process.
• the position transmitter 68 opens and the circuit 62 is interrupted.
• the switching magnet 56 is no longer energized and the switching valve 54 is moved back into its basic position by the spring force of its biasing spring, in which the connecting lines 30, 58 are again blocked off from one another.
• the activation switch 66 opens again due to the interruption of the circuit 62 or is reset manually by the driver. Due to the resetting of the switching valve 54 into its basic position, the control pressure of the boom control unit 12 which is effective in the direction of the pivoting in of the blade 6 can no longer be guided to the blade proportional valve 26.
• control chamber 52 previously acted upon by the control pressure is relieved of pressure via the blade connecting line 58, the shuttle valve 60 and the switching valve 54 to the tank, and thus the control pressure difference between the control spaces 50, 52 is eliminated, whereby the blade proportional valve 26 again assumes its spring-loaded neutral position. The blade 6 is thus transferred to its desired position.
• the driver actuates the bucket control lever 22 in such a way that the bucket pilot control device 18 generates a control signal, so that the control spaces 50, 52 of the bucket proportional valve 26 have a Control pressure difference are applied and this is shifted from its neutral position to the right.
• the position transmitter 68 is closed automatically, so that the process described above can virtually begin again.
• the control arrangement according to the invention forwards a control signal of the boom control unit 12 which is effective in the direction of a lowering movement of the boom 2 to the bucket control unit 14, so that the bucket 6 is transferred to a corresponding desired position.
• a control arrangement for a working device in particular a wheel loader or a backhoe loader, which has a bucket articulated on a boom, the control arrangement enabling the bucket to be actuated by means of a control pressure of a boom control unit, so that the boom control unit is lowered or when the boom is transferred Cantilever can be brought into a floating position in a target position.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Operation Control Of Excavators (AREA)
• Lifting Devices For Agricultural Implements (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34625227

Family Applications (1)

Country Status (5)

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Family Cites Families (11)

• 2003
  • 2003-11-25 DE DE10354957A patent/DE10354957A1/de not_active Withdrawn
• 2004
  • 2004-11-22 WO PCT/DE2004/002576 patent/WO2005052266A1/fr active Application Filing
  • 2004-11-22 EP EP04802787A patent/EP1687490B1/fr not_active Not-in-force
  • 2004-11-22 US US10/576,709 patent/US7357064B2/en not_active Expired - Fee Related
  • 2004-11-22 AT AT04802787T patent/ATE470023T1/de not_active IP Right Cessation
  • 2004-11-22 DE DE502004011246T patent/DE502004011246D1/de active Active

Non-Patent Citations (1)

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