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
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
• • 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
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
  • F15B15/1423—Component parts; Constructional details
  • F15B15/1447—Pistons; Piston to piston rod assemblies
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49229—Prime mover or fluid pump making
  • Y10T29/49249—Piston making
  • Y10T29/49252—Multi-element piston making

Definitions

• Device with at least one boom or support arm for multi-unit crane-like booms, concrete placing booms and the like.
• the present invention relates to a Vorrichti g with at least one boom or support arm for crane-like booms, concrete distribution masts, aerial work platforms, manipulators and the like. Multi-unit work units.
• the invention further relates to a method for producing such a device, in particular a hydraulic differential cylinder used for the device.
• the invention relates to the formation of a concrete placing boom of a movable or stationary concrete pump, in which the mast consists of different mast sections that are folded and optionally also telescopic, the mast arms being actuated in particular by hydraulic differential cylinders.
• hydraulic differential cylinders In the case of concrete placing booms, which are constructed from articulated mast arms that can be folded together for reasons of space, but can be swung out or extended for operation, comparatively large hydraulic differential cylinders are used, in particular for the lowest or the lowest mast arms or support arms, which act as the drive used for raising and lowering and, if necessary, for telescoping a mast arm. Hydraulic cylinders with a stroke length of up to 2.5 m and more are used. It goes without saying that these hydraulic differential cylinders must be designed to be correspondingly large and dimensionally stable, so that they absorb the forces which occur when the entire mast is actuated, in particular they can extend and move the mast arms reliably and reliably.
• the object of the invention is to develop a device of the generic type in such a way that a clever reduction in weight enables the device to be reduced in weight by means of the hydraulic differential cylinders, which act as a drive for the boom or support arms of multi-unit, crane-like booms, concrete placing booms and the like used and should therefore be designed to save weight.
• the hydraulic differential cylinders are designed to be lightweight in that the piston rod is made hollow.
• the hollow piston rod in this case comprises a tubular segment and end pieces arranged at the ends of the tubular segment, in particular an end piece on the piston side, preferably closed on the end face, and an end piece on the rod eye side.
• a piston is arranged on the piston-side end piece, either via screw connections or a thread.
• the piston can optionally also be welded on.
• the tubular segment and the end pieces are either formed in one piece or connected to one another by a material connection. In the case of a cohesive connection of at least one of the end pieces to the tubular segment, it is expedient that an end piece is welded onto at least one side.
• the opposite end section of the tube can be suitably formed by either welding or attaching another end piece in some other way, for example by means of threads or screws.
• the opposite end section can also be formed in one piece with the tubular segment.
• both ends of the piston rod designed as a tubular segment or tube can also be welded to corresponding end pieces.
• the piston rod In the case of a one-piece design of the piston rod, it is produced from a cast blank with subsequent machining from one end of the piston rod in order to make the piston rod hollow.
• a heavy-duty material with a tensile strength of over 700 N / mm 2 is used, from which the hollow piston rod can be made, which leads to a very heavy-duty piston rod.
• the inventors have recognized that for the dimensioning of these hydraulic cylinders, which ultimately have to move the entire masses of a concrete placing boom above, it is advantageous if the occurrence of moving hydraulic differential cylinders notch stresses is reduced or minimized. Taking notch stresses into account leads to the fact that the wall thickness of the components of the hydraulic differential cylinders is generally dimensioned accordingly strong. This is accompanied by a corresponding increase in weight. However, if you reduce the notch stresses that can occur during operation, the wall thicknesses of the components of the hydraulic differential cylinder can be dimensioned in a correspondingly more favorable thickness. This can bring considerable weight advantages when you consider that very often long-stroke hydraulic cylinders with stroke lengths of 2.5 m and more have to be used.
• this is achieved by reworking the weld seam areas, in particular on the inner tube side of the segment, by machining and smoothing. Accessibility for the tool is ensured in that at least one of the end pieces has an opening through which the cutting tool and, if appropriate, the smoothing tool can be carried out and the machining can be carried out.
• the invention is also generally applicable to hydraulic differential cylinders which are used independently of the above-mentioned applications, but the preferred field of application is crane-like booms, concrete placing booms and comparable manipulators.
• an opening is provided at least on one end piece of the hollow piston rod a machining tool gains access to the piston rod cavity.
• a machining tool gains access to the piston rod cavity.
• a particularly simple method of integral connection is welding, in particular the end face welding of the end pieces to the tubular segment.
• FIG. 1 shows a cross section through a hydraulic differential cylinder suitable for the movement of a cantilever or support arm
• Figure 2 is a detailed view of the welded joint of Figure 1 in cross section and
• FIG. 3 shows the cross section of a further embodiment of such a hydraulic
• Figures 4 and 5 cross sections of cylinders with an integral piston rod.
• FIG. 1 shows a cross-sectional view of an embodiment of a hydraulic differential cylinder 1 according to the invention.
• the hydraulic cylinder 1 in this case consists of the cylinder tube 3 and the piston rod 2, which is displaceably arranged in the cylinder tube 3 and is designed as a hollow piston rod 2.
• the hollow piston rod 2 comprises a tubular segment 4, at the ends of which the piston-side end piece 5 and the rod-eye end piece 6 are provided, the piston 11 being arranged on the piston-side end piece 5 by screw connections 10.
• the rod eye end piece 6 has two laterally projecting pipe sockets 13, 14 for connecting the piston rod to the mast arm or the like. As well as an opening 8 through which access to the interior of the hollow piston rod 2 is possible from the outside.
• the cross section of the piston wall 9 is consistently smooth and flat over the entire area of the tubular segment 4, the transition to the end pieces 5, 6 also being designed such that no notch effects occur.
• the provision of a sufficiently large radius of curvature ensures that no inadmissible notch effects occur.
• the hollow piston rod is made via welded connections 7 from the end pieces 5 and 6 and the tubular segment 4.
• the weld seams 7, which in the exemplary embodiment shown are V-seams, are designed by means of mechanical machining postprocessing in such a way that there is a flat and smooth and flush transition at the interface between the parts to be connected. This prevents protruding parts of the welded connection, as shown in FIG. 2, from contributing to a notch effect.
• a in FIG. 2 denotes the notch factor-free residual weld seam after machining, after machining, so that there the outer surface in the seam area is flush with the adjacent pipe surfaces.
• Fig. 3 also shows a further embodiment of a hydraulic cylinder 1 according to the invention, in which the hollow piston rod 2 has a welded end piece 6, the weld seams being designated by 7. Otherwise, the hollow piston rod 2 can be made of solid material and thus be made in one piece with the end piece 5, which is compressed in the exemplary embodiment shown.
• the compression zone is designated by 12.
• With 13 a thread is shown, which is applied to the outer surface of the end piece 5.
• a corresponding thread is provided on the piston 11, which can thus be screwed to the end piece 5.
• the breakthrough for tool access which is designated 8 and allows access to the interior of the hollow piston rod 2, is provided here on the piston-side end piece 5.
• Figures 4 and 5 show embodiments of a hydraulic differential cylinder 1, in which the hollow piston rod is formed in one piece.
• a cast blank is preferably used, which in the embodiment according to FIG. 4 is machined from the upper end of the piston rod to form the cavity.
• the inner wall 15 of the rod end 6 and the tubular segment 4 is smoothed by machining in order to avoid the occurrence of notch effects.
• the transition to the end face takes place by rounding 17 which avoids notch effects.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Actuator (AREA)
• Jib Cranes (AREA)
• Load-Engaging Elements For Cranes (AREA)
• Manipulator (AREA)
• On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
• Shovels (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7668513

Family Applications (1)

Country Status (12)

Families Citing this family (10)

Family Cites Families (8)

• 2000
  • 2000-12-22 DE DE10064365A patent/DE10064365B4/de not_active Expired - Fee Related
• 2001
  • 2001-12-21 EP EP01995711A patent/EP1346157B1/fr not_active Expired - Lifetime
  • 2001-12-21 AT AT01995711T patent/ATE417205T1/de active
  • 2001-12-21 DE DE50114572T patent/DE50114572D1/de not_active Expired - Lifetime
  • 2001-12-21 CN CNB018211356A patent/CN1278051C/zh not_active Expired - Lifetime
  • 2001-12-21 TR TR2003/01826T patent/TR200301826T3/xx unknown
  • 2001-12-21 BR BRPI0116784-7A patent/BR0116784B1/pt not_active IP Right Cessation
  • 2001-12-21 KR KR1020037008240A patent/KR100618139B1/ko not_active IP Right Cessation
  • 2001-12-21 JP JP2002553581A patent/JP4008815B2/ja not_active Expired - Fee Related
  • 2001-12-21 ES ES01995711T patent/ES2204359T3/es not_active Expired - Lifetime
  • 2001-12-21 US US10/451,563 patent/US7007590B2/en not_active Expired - Fee Related
  • 2001-12-21 WO PCT/EP2001/015222 patent/WO2002052115A2/fr active IP Right Grant
• 2003
  • 2003-11-29 HK HK03108738.7A patent/HK1056384A1/xx not_active IP Right Cessation

Non-Patent Citations (1)

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