Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
  • F15B1/02—Installations or systems with accumulators
  • F15B1/024—Installations or systems with accumulators used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2217—Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
  • F15B21/14—Energy-recuperation means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2201/00—Accumulators
  • F15B2201/30—Accumulator separating means
  • F15B2201/31—Accumulator separating means having rigid separating means, e.g. pistons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2201/00—Accumulators
  • F15B2201/30—Accumulator separating means
  • F15B2201/32—Accumulator separating means having multiple separating means, e.g. with an auxiliary piston sliding within a main piston, multiple membranes or combinations thereof

Definitions

• the invention relates to a device for energy saving in hydraulically actuated work equipment, with a supply unit, in particular in the form of a hydraulic pump and a piston accumulator with at least two in a storage housing longitudinally movable pistons which are interconnected via a coupling part, the longitudinally movable in at least one partition is guided, which surrounds the coupling part surrounding cylinder annular spaces, wherein a cylinder space is connected as a pressure actuation space for the required pressure for a working fluid supply to the working equipment, at least one other cylinder space via a pressure control device to the supply unit is connected and another cylinder space forms a pressure storage space ,
• Such energy saving and recovery devices are known from EP 0 897 480 B1 and EP 1 254 319 B1.
• an increased internal pressure which decreases in the direction of relaxation, arises as soon as the pistons in the other travel direction increase in size Move volume of the accumulator chamber.
• Spaces enclosed fluid amount forms a kind of energy storage, comparable to a mechanical spring, and the introduced by the movement in the storage space kinetic energy of the working equipment can be recalled.
• the piston accumulator as a central part of the energy saving and recovery device is permanently connected to the working equipment, so that continuously in dependence on the working movement of the working equipment energy stored in the piston accumulator and retrieved from there again.
• the work equipment can be in particular work machines, such as excavators or the like, in which boom to raise and lower, but if necessary, such devices can also be used in other hydraulic systems, such as hydraulic brake systems, in elevators and hydraulic motors or similar.
• such devices can be used in work equipment, such as excavators or the like, as a load compensation system, wherein a middle piston or boom position of the hydraulically actuated working equipment associated with a corresponding internal pressure in the accumulator chamber, which, when the boom is to be lifted under load, below usable energy release relaxed.
• a hydraulic oscillator is known as the drive of machines.
• two hydraulic cylinders act on a machine axis to be driven. This creates four cylinder chambers that are hydraulically linked to the machine axis.
• a cylinder space per cylinder is in this case connected to one of the two ports of a hydraulic pump.
• the respective other cylinder space of the two cylinders is connected to one energy storage.
• To drive the hydraulic pump is an electric motor provided and during its operation, the machine axis moves in one direction.
• a reversal of direction of the electric motor has a corresponding direction reversal of the machine axis result.
• the disclosed embodiments of the known solution all show those cylinder chambers connected to the hydraulic pump, which are interspersed in each case by a rod-like coupling part as a cylinder rod and thus form annular cylinder chambers with annular cross-section. Since in this case the hydraulic pump can thus act in each case only on an annular partial surface of the piston, the application of a relatively high pressure levels is required to achieve the forces required for the actuation of the machine axis.
• the present invention seeks to provide a device of the type considered available, which is characterized by a particularly favorable performance, especially when used for load compensation systems. According to the invention this object is achieved by a device having the features of claim 1 in its entirety.
• a significant feature of the invention is that of the separated by the respective partition cylinder chambers of the piston accumulator, which surround the coupling part as a cylinder annulus, a cylinder annulus as accumulator chamber and the other cylinder annulus as connected to the implement shaft pressure actuation space is provided.
• the supply unit preferably operates in the form of a hydraulic pump in the invention it is in communication with a cylinder space adjacent to a full-surface piston side, with a lower pressure level, which is more favorable both energetically and operationally. Since both the accumulator chamber and the pressure actuation chamber are each cylinder annular spaces, which lead to the higher pressure level, the system is also characterized by an increased energy density, whereby a compact, space-saving design can be realized.
• the accumulator chamber can be connected to a pressure supply device and the cylinder chambers are accommodated adjacent to the dividing wall in the accumulator housing.
• hydraulic fluid When located in the pressure accumulator space hydraulic fluid may be at least one hydraulic accumulator in the pressure supply device, for example in the form of a bladder accumulator. However, one or more piston accumulators can also be provided.
• the pressure control device may comprise at least one controllable switching valve, by means of which the hydraulic pump can be connected to an associated, adjacent to a full-surface side of the piston cylinder space.
• the working equipment may comprise at least one hydraulically actuable working cylinder, which is preferably connectable with its adjacent to the full-surface piston side of its working piston working space with the pressure actuating chamber of the piston accumulator.
• the return movement of the working piston of the working equipment can be carried out in a passive manner by the force acting on the extended working piston load or counterforce of the working equipment or, alternatively, by an active return movement is effected, wherein a Free cylinder space of the piston accumulator, so in the present case, a cylinder space adjacent to a full-surface piston side, is connected to the supply unit. Also, a rod-side space of the working cylinder can be connected to the supply unit, in particular in the form of a hydraulic pump.
• FIG. 2 to 5 corresponding representations of further embodiments of the device
• FIG. 1 The exemplary embodiment of the device according to the invention shown in FIG. 1 in the form of a schematically simplified circuit diagram serves for energy saving and recovery in hydraulically actuated working devices, of which only one working cylinder is shown in FIG. 1 and designated 1.
• the working cylinder 1 is hydraulically actuated to produce a working or extending movement of its working piston 3, which takes place against a load or counterforce, which is indicated in Fig. 1 with an arrow F. This may be the load of a crane jib or the like.
• the device further has a piston accumulator in the form of a double-piston accumulator 5, in whose housing 7 at least two longitudinally movable pistons 9 and 11 are arranged. These are connected to their respective adjacent opposite piston 9 and 1 1 via a rod-like coupling member 13 firmly together.
• the coupling member 13 itself is longitudinally movable approximately centrally in a partition wall 1 5 of the housing. 7 guided.
• the partition wall 15 delimits with the two adjacently opposing pistons 9, 11 two annular cylinder spaces surrounding the coupling part 1 3, of which one cylinder annular space forms an accumulator space 17 and the other cylinder annular space forms a pressure actuation space 19.
• the latter is connected via a pressure line 21 for the required for a working pressure supply to the working cylinder 1 of the working equipment, ie this piston serves as a pressure actuating piston 1.
• the pressure actuating piston 1 1 adjoins with its full-surface side of the piston to a pump chamber 23 which is connected via a pump line 25 to a pressure control device 27.
• This has a controllable switching valve 29, which is formed in the example of Fig. 1 by a 2/2-way valve, via which the pump line 25 with a hydraulic pump 31 is connected as a supply unit.
• the pump chamber 23 opposite cylinder chamber 33 which is adjacent to the full-surface piston side of the piston 9, as a cylinder chamber 33 to the tank 35 can be ventilated or alternatively evacuated.
• piston 9 pressure accumulator space 1 7 in the form of the coupling part 13 surrounding the cylinder derringraumes is connected to a pressure supply device 37 in connection.
• the pressure storage space 1 7 contains a liquid pressure medium, for example hydraulic oil
• the pressure supply device 37 has a hydraulic accumulator 39.
• gaseous pressure medium, for example, N 2 the Druckerssein- device 37 may have a nitrogen-filled pressure vessel.
• Fig. 1 shows the device in an operating condition corresponding to the center position of the working piston 3 and the piston 9 and 1 1 of the double piston accumulator 5.
• the preloading pressure which prevails in the pressure accumulator space 1 7 is equal to the pressure generated by the opposing force F in the working cylinder 1, which prevails via the line 21 in the pressure actuation space 19 Internal pressure off.
• a return movement of the working piston 3, which causes the pressure line 21 in the pressure actuating chamber 19 pressure increase leads to a displacement of the piston 9 and 1 1 in the Fig.
• the pressure of the gas cushion generating the compensation force in the pressure storage space 17 is preferably lower than the pressure generated by the counterforce F acting as a load force in the pressure actuation space 19.
• the exemplary embodiment of FIG. 2 corresponds to the example of FIG. 1, except that the cylinder space 33 of the double-piston accumulator 5 designated as ambient space in FIG. 1 is not directly connected to the tank 35, but is connected to the switching valve 29 via a line 41 is. This is formed in the embodiment of Fig.
• FIG. 3 also corresponds to the example of FIG. 1, except that the pressure supply device 37 has two hydraulic accumulators 61 and 63 in the form of bladder accumulators. These are either by means of switching valves 65 and 67 individually or together with the pressure accumulator space 1 7 connectable. As a result, different pressure levels on the working cylinder 1 and different working characteristics are available as desired.
• piston accumulators 69 and 71 may be provided instead of bladder accumulators 61, 63 in such an embodiment.
• the memory design can be made in this case so that accumulator piston can put on the oil side, the bias voltages of the memory are selected so that when a decrease in the load first a memory 69 or 71 and then the other memory 69 or 71 is filled.
• the piston accumulators 69, 71 associated switching valves 73 and 75 may then be omitted if necessary.
• FIG. 5 shows an exemplary embodiment in which the cylinder annular spaces, ie the pressure accumulator space 17 and the pressure actuation space 19, are not separated from each other by a single, common dividing wall 15 but by two dividing walls 79 and 81 located at a distance from one another , wherein the coupling part of the pistons 9 and 1 1 is formed by a split, a hinge point 83 having piston rod 85.
• the housing of the double piston accumulator 5 is separated by two Partial cylinder 87 and 89 formed, which may be to save costs to standard hydraulic cylinder.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Fluid-Pressure Circuits (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (4)

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Citations (5)

• 2012
  • 2012-05-03 DE DE201210009669 patent/DE102012009669B3/de not_active Expired - Fee Related
• 2013
  • 2013-04-20 WO PCT/EP2013/001182 patent/WO2013164073A1/fr not_active Ceased

Patent Citations (5)

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