EP0158738A2 - Dispositif hydraulique de protection contre les surcharges pour une grue de chargement - Google Patents

Dispositif hydraulique de protection contre les surcharges pour une grue de chargement Download PDF

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Publication number
EP0158738A2
EP0158738A2 EP84116255A EP84116255A EP0158738A2 EP 0158738 A2 EP0158738 A2 EP 0158738A2 EP 84116255 A EP84116255 A EP 84116255A EP 84116255 A EP84116255 A EP 84116255A EP 0158738 A2 EP0158738 A2 EP 0158738A2
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EP
European Patent Office
Prior art keywords
control
valve
protection device
overload protection
directional
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP84116255A
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German (de)
English (en)
Other versions
EP0158738A3 (fr
Inventor
Wolfgang Dipl.-Ing. Kötter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0158738A2 publication Critical patent/EP0158738A2/fr
Publication of EP0158738A3 publication Critical patent/EP0158738A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/88—Safety gear
    • B66C23/90—Devices for indicating or limiting lifting moment

Definitions

  • the invention relates to a hydraulic overload protection device for a hoist, in particular a loading crane, according to the preamble of the main claim.
  • a hydraulic overload protection device for a hoist, in particular a loading crane, according to the preamble of the main claim.
  • Such an overload protection device is already known from DE-AS 21 54 631, in which a 3-section boom arm consisting of crane column, inner arm and outer arm can be actuated by two double-acting hydraulic cylinders, each of which is controlled via 4/3-way valves.
  • the outer arm can assume positions pivoted upwards and downwards relative to a horizontal, as a result of which, when the hydraulic cylinder moves in the same direction, a change in the load-torque-increasing working position on the directional control valve occurs.
  • a disadvantage of the hydraulic overload protection device is that the directional control valve which controls the outer arm can only be reset from a single working position to a central position in order to limit the load moment on the loading crane.
  • the change in the switching torque-increasing switching position depending on the position of the outer arm becomes horizontal not considered here.
  • it is disadvantageous that from the inner arm actuating hydraulic cylinder is guided via a safety valve to a plurality of return piston of the directional control valves with a response of the load torque limit pressure medium is increased, and which on the other hand to a load torque-increasing movement of the boom can lead.
  • the safe functioning of the overload protection device is thereby impaired.
  • an overload protection device for a loading crane in which the change in the switching torque-increasing switching position on the directional control valve is taken into account.
  • an electrical position sensor that controls an electrical switch is arranged on the cantilever arm part that is adjustable relative to the horizontal.
  • the switch in turn controls a solenoid valve which, when the overload protection device responds, optionally controls the pressure medium arriving via a safety valve into one of two control chambers of a double-acting resetting device on the directional control valve, whereby its control slide is returned at least to a middle position from the load-torque-increasing working position.
  • the disadvantage of this overload protection device is that it does not allow fully hydraulic operation. By using an electrical position sensor, a switch and a solenoid valve, it builds relatively complex and expensive.
  • the hydraulic overload protection device according to the invention for a hoist with the characterizing features of the main claim has the advantage that it is a fully hydraulic control he possible, which automatically takes into account the change in the switching moment-increasing switching position in a directional control valve for controlling a cantilever arm part. This eliminates the need for electrical components.
  • the overload protection device also uses relatively simple components. The safety of the overload protection device is increased by the fully hydraulic operation.
  • a design according to claim 2 is particularly advantageous, as a result of which pressure medium coming from the pump is used to reset the control slide in the directional control valves, which favors the safe functioning of the overload protection device.
  • a particularly space-saving and inexpensive solution arises according to claim 3, if in this way hydraulic stops for the control slide are formed in the directional control valve.
  • a design according to claim 6 is also particularly expedient, as a result of which only two control lines have to be led to the hydromechanical position sensor on the cantilever arm part.
  • an embodiment of the position sensor as a shuttle valve according to claim 7 is particularly advantageous, as a result of which the valve outlay in the overload protection device is kept relatively low. Further advantageous embodiments result from the remaining claims, the description and the drawing.
  • FIG. J shows a first exemplary embodiment of a hydraulic overload protection device for a loading crane with a two-way ball valve as a position sensor and Figure 2 with a shuttle valve as a position sensor, each in a simplified representation.
  • FIG. 1 shows a hydraulic overload protection device 10 for a loading crane, which has a three-part boom 11.
  • the cantilever arm 11 essentially consists of three cantilever arm parts which are movable relative to one another, namely a crane column 13 fastened to a support frame 12, an inner arm 14 pivotably mounted on the latter and an outer arm 15 pivotably articulated on the inner arm 14 , which is controlled by a first directional valve 17.
  • the outer arm 15 can assume a position above and below the horizontal 21 in operation relative to a horizontal 21.
  • the switching torque-increasing switching position in the second directional valve 19 is thus dependent on the position of the outer arm 15 with respect to the horizontal 21.
  • the second directional valve 19 has a control slide 22, which is centered by the double-acting return device 23 in a central position 24 and can be deflected with the aid of a manual actuation device 25 to both sides into working positions which are designed as a lifting position 26 and as a lowering position 27.
  • the second directional valve 19 has two motor connections labeled A, B, of which the first (28) ver via a first motor line 31 with the annular piston rod space 32 in the articulated cylinder 18 is bound.
  • the second mecran connection 29 is connected via a second motor line 33 to a cylinder space 34 of the articulated cylinder 18.
  • An inlet connection 35 of the second directional valve 19 is secured in a manner known per se by a check valve 36 and is connected via an inlet line 37 to the outlet of a pump 38 which sucks pressure medium from a tank 39.
  • a return port 41 of the second directional valve 19 is relieved via a return line 42 to the tank 39.
  • a neutral circulation channel 43 is guided over the control slide 22 of the directional control valve 19, which branches upstream of the directional control valve 19 from the feed line 37 and opens downstream of the control slide 22 into the return line 42.
  • control slide 22 protrudes with its front ends into a control chamber 44 or 45, which is only shown in simplified form, so that its pressure can act on the full slide end face.
  • a first branch line L6 leads from the first control chamber 44 via a first throttle point 47 and correspondingly from the second control chamber 45 a second branch line 48 via a second throttle 49 to a control line 51 which is connected to an outlet 52 of a safety valve 53.
  • a first control connection 54 is guided from the first control chamber 44 and, correspondingly from the second control chamber 45, a second control connection 55 is led to the return line 42 in a manner that can be influenced by the control slide 22.
  • the control slide 22 is now designed such that it blocks the working connections 28, 29, 35, 41 in its central position 24 and keeps the neutral circulation channel 43 open, while at the same time the two control connections 54, 55 can relieve the control chambers 44 and 45 to the tank 39.
  • the neutral circulation channel 43 is blocked; while the first control connection 54 is open, the second control connection 55 is blocked in the raised position 26.
  • the neutral circulation channel 43 is also blocked, as is the first control connection 54, while the second control connection 55 is open.
  • the two control chambers 44 and 45 on the control slide 22 are also connected via two control channels 56, 57 to the inputs of a 3/2-way selection valve 58, the outlet 59 of which is relieved to the tank 39.
  • the selector valve 58 has a spring-centered basic position 61, in which it relieves the pressure on the second control channel 57 and blocks off the first control channel 56.
  • the selection valve can be moved against the force of its spring into a switching position 62, in which it swaps the relief or blocking of the two control channels 56, 57.
  • a hydromechanical position sensor 63 is arranged on the outer arm 15 and is designed here as a ball valve. It has an uncontrolled connection 64 which is connected in parallel to the control circuit 46, 48, 54, 55 on the second directional valve 19 to the control line 5.1.
  • a controlled connection 65 of the position sensor 63 is connected via a pilot line 66 to the control connection 60 of the selection valve 58. In addition, the pilot line 66 is relieved via a throttle point 67 to the tank 39.
  • the position sensor 63 is designed such that when the exterior is pivoted over the horizontal 21 arm 15 the ball remains in its one end position, whereby it blocks the connection between the two connections 64 and 65. If, on the other hand, the outer arm 15 is pivoted below the horizontal 61, the ball in the position sensor 63 rolls into its other end position and thereby releases the connection between the two connections 64, 65.
  • the adjustable safety valve 53 has an inlet 68 which is connected in parallel to the inlet line 37 to the outlet of the pump 38.
  • a tank connection 69 on the safety valve 54 is relieved to the tank 39.
  • the safety valve 53 is adjustable and is centered by a spring in a zero position 71, in which it relieves the control line 51.
  • a control connection 72 on the safety valve 53 is connected via a pressure line 73 to a pressure chamber 74 in the lifting cylinder 16, which is used as a load torque indicator, so that it switches to a switching position 75 when a predetermined load torque limit is reached, and thereby the control line 51 with the pump 38 connects.
  • the first directional control valve 17 for controlling the lifting cylinder 16, like the second directional control valve J9, is designed as a 4/3 valve. It differs from the second directional valve 19 as follows, the same reference numerals being used for the same components, but with the index '.
  • the motor connection 28 ′ denoted by A is connected via a first consumer line 76 to the pressure chamber 74 in the lifting cylinder 16, while its annular space 77 is connected to the second motor connection 29 ′ via a second consumer line 78.
  • the restoring means are designed such that its control slide 22 1 only from the lower position 27 'into its central position lung 24 'is resettable.
  • the control slide 22 ' is therefore assigned only a second control chamber 45' which can be relieved via the second control connection 55 'to the return line 42 and is connected to the control line 51 via the throttle 49' parallel to the second directional valve 19.
  • the first directional valve 17 is connected to the inlet line 37 and the return line 42 parallel to the second directional valve 19 and is located upstream of the second directional valve 19 in the neutral circulation channel 43.
  • a pressure relief valve 79 is used to protect the pump 38.
  • the pressure medium flows via the control line 51 into the control circuit of the second directional valve 19. It should now be assumed that the control slide 22 is in the center position 24 shown and the outer arm 15 is a position above the horizontal 21 ingest.
  • the pressure prevailing in the control line 51 also passes through the uncontrolled connection 64 into the position sensor 63, in which, however, the spherical closing member blocks the controlled connection 65 when the outer arm 15 is in the position shown.
  • the outer arm 15 occupies a position not shown, with its free end being pivoted below the horizontal 2J.
  • the ball in the position sensor moves into its other end position, as a result of which the connection between the two connections 64 and 65 is open.
  • the pressure medium entering the control line 51 when the safety valve 53 is open now flows over the position sensor 63 into the pilot line 66 and pushes the selector valve 58 into its switching position 62, whereby the first control channel 56 is relieved and the second control channel 57 is blocked.
  • the throttle point 67 is selected to be so small that it does not interfere with this switching process at the selection valve 58 when the safety valve 53 is open.
  • the outer arm 15 can also be operated by itself while the inner arm 14 is at rest. If the outer arm 15 is in the position shown above the horizontal 21, the control slide 22 can be easily adjusted into its raised position 26, the outer arm being pivoted further counterclockwise. The pivotal movement is not disturbed when the safety valve 53 responds. If, on the other hand, the outer arm 15 is moved further counterclockwise from the position shown in the lowered position 27 of the control slide 22 and the load torque limit is exceeded, the pressure medium coming from the pump 38 via the safety valve 53 and the control line 51 to the second directional control valve 19 in the the first control chamber 44 the control slide back into its central position 24 and thereby ends the lowering movement of the outer arm 3 15 which increases the load torque.
  • the second control connection 55 is blocked and also the second control channel 57 is blocked by the selection valve 58, so that the pressure building up via the throttle 49 in the second control chamber 45 resets the slide 22 to its central position 24.
  • the selector valve 58 can be moved by its spring from the switching position 62 back to its basic position 61, pressure medium being able to escape from the control connection 60 via the throttle point 67 to the tank 39.
  • the present overload protection device JQ thus enables a fully hydraulic load torque limitation on the cantilever arm 11 by resetting the control slides 22, 22 'in the directional control valves 19, 17. With the help of the hydromechanical position sensor 63 and the selection valve 58, the resetting is automatically controlled so that movements increasing the load torque are independent of the position of the outer arm 15 relative to the horizontal 21 can always be avoided.
  • FIG. 2 shows a second overload protection device 90 which differs from that according to FIG. 1 as follows, the same parts being provided with the same reference numerals.
  • the second overload protection device 90 differs primarily by another hydromechanical position sensor 91, which is now essentially designed as a shuttle valve and is connected to the control circuit of the directional control valve 19 in such a way that a selection valve is unnecessary.
  • the control line 51 is only indirectly connected via the position sensor to the control circuit on the second directional valve 19 and is connected to a center connection 92 of the position sensor for this purpose.
  • a first pilot line 94 leads from a first side connection 93 of the position sensor 91 via an inlet throttle 95 to the first control chamber 44.
  • a second pilot line 91 leads from a second side connection 96 on the position sensor 91 via a second inlet throttle 98 to the second control chamber 45.
  • the inlet throttles 95, 98 perform the same function as the throttle 47, 49 according to FIG. 1, namely to throttle the inflowing control oil flow.
  • each control chamber is now connected to the return line 42 via an outlet channel 99, 101, the pressure medium outflow being limited in each case by a first or second outlet throttle 102 or 103.
  • the free flow cross-section of the outlet throttles 102, 103 is designed to be substantially smaller than that of the inlet throttles 95, 98, so that a control pressure can build up in the control chambers 44, 45 when the control connections 54 and 55 are blocked.
  • the mode of operation of the second overload protection device 90 is in principle similar to that of the first overload protection device 10. The difference is that the function of the selection valve 58 according to FIG Position sensor 93 is integrated, via which the pressure medium supply from the control line 51 to the two control chambers 44, 45 now also takes place depending on the position of the outer arm 15. The ratio of the flow cross sections of the inlet throttle 95 to the associated outlet throttle 102 is selected so that sufficient pressure can be built up in the first control chamber 44 to reset the control slide. With the second overload protection device 90, the valve outlay is reduced; on the other hand, an additional control oil line to the position sensor 93 on the outer arm 15 is required.
  • position sensors can also be designed as pendulum valves or in another design.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Jib Cranes (AREA)
EP84116255A 1984-04-14 1984-12-22 Dispositif hydraulique de protection contre les surcharges pour une grue de chargement Withdrawn EP0158738A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843414183 DE3414183A1 (de) 1984-04-14 1984-04-14 Hydraulische ueberlastungsschutzvorrichtung fuer einen ladekran
DE3414183 1984-04-14

Publications (2)

Publication Number Publication Date
EP0158738A2 true EP0158738A2 (fr) 1985-10-23
EP0158738A3 EP0158738A3 (fr) 1988-10-19

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP84116255A Withdrawn EP0158738A3 (fr) 1984-04-14 1984-12-22 Dispositif hydraulique de protection contre les surcharges pour une grue de chargement

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EP (1) EP0158738A3 (fr)
DE (1) DE3414183A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104555766A (zh) * 2015-01-12 2015-04-29 徐州徐工随车起重机有限公司 一种折臂随车起重机液压控制力矩限制系统
CN104847726A (zh) * 2015-04-17 2015-08-19 徐州徐工随车起重机有限公司 一种终端解除型力矩限制阀及设有该阀的液控力矩限制系统
CN104847725A (zh) * 2015-04-17 2015-08-19 徐州徐工随车起重机有限公司 一种新型力矩限制阀及设有该阀的液压控制力矩限制系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3678905D1 (de) * 1985-11-27 1991-05-29 Oil Control Spa Hydraulische lastbegrenzungsvorrichtung fuer hydraulische krane.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2338862A1 (de) * 1972-08-14 1974-02-28 Tico Ab Ueberlast-schutzsystem fuer lastkraene mit servosteuerung
DK131618B (da) * 1973-01-26 1975-08-11 Hojbjerg Maskinfabrik As Kran, navnlig lastvognskran med en lastmomentbegrænsende styreindretning.
DE2154631B2 (de) * 1970-11-04 1977-07-21 Hiab Foco AB, Hudiksvall (Schweden) Ueberlastungsschutzvorrichtung fuer einen ladekran
EP0003939A2 (fr) * 1978-03-01 1979-09-05 Michel Gutierrez Perfectionnement aux appareils de levage à commande hydraulique
GB2078197A (en) * 1980-06-04 1982-01-06 Hiab Foco Ab Load limiting device
EP0055247A2 (fr) * 1980-12-23 1982-06-30 Firma PALFINGER Grue de chargement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2154631B2 (de) * 1970-11-04 1977-07-21 Hiab Foco AB, Hudiksvall (Schweden) Ueberlastungsschutzvorrichtung fuer einen ladekran
DE2338862A1 (de) * 1972-08-14 1974-02-28 Tico Ab Ueberlast-schutzsystem fuer lastkraene mit servosteuerung
DK131618B (da) * 1973-01-26 1975-08-11 Hojbjerg Maskinfabrik As Kran, navnlig lastvognskran med en lastmomentbegrænsende styreindretning.
EP0003939A2 (fr) * 1978-03-01 1979-09-05 Michel Gutierrez Perfectionnement aux appareils de levage à commande hydraulique
GB2078197A (en) * 1980-06-04 1982-01-06 Hiab Foco Ab Load limiting device
EP0055247A2 (fr) * 1980-12-23 1982-06-30 Firma PALFINGER Grue de chargement

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104555766A (zh) * 2015-01-12 2015-04-29 徐州徐工随车起重机有限公司 一种折臂随车起重机液压控制力矩限制系统
CN104555766B (zh) * 2015-01-12 2016-08-24 徐州徐工随车起重机有限公司 一种折臂随车起重机液压控制力矩限制系统
CN104847726A (zh) * 2015-04-17 2015-08-19 徐州徐工随车起重机有限公司 一种终端解除型力矩限制阀及设有该阀的液控力矩限制系统
CN104847725A (zh) * 2015-04-17 2015-08-19 徐州徐工随车起重机有限公司 一种新型力矩限制阀及设有该阀的液压控制力矩限制系统

Also Published As

Publication number Publication date
DE3414183A1 (de) 1985-10-24
EP0158738A3 (fr) 1988-10-19

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