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
  • F15B15/20—Other details, e.g. assembly with regulating devices
  • F15B15/26—Locking mechanisms
  • F15B15/261—Locking mechanisms using positive interengagement, e.g. balls and grooves, for locking in the end positions

Definitions

• the invention relates to a fluid-operated device
• EP-A-219 594 A generic device describes EP-A-219 594. This has proven itself for numerous practical applications. However, the full axial force is only transmitted when the locking elements have reached their innermost radial position, so that a full-surface contact of the corresponding corresponding surfaces is achieved. If the full-surface contact is reached, the end of the movement is also reached at the same time, so that a further axial movement of the piston rod used is no longer possible. This is sufficient in numerous applications.
• DE-A-29 11 071 describes a locking device for piston rods of fluid-actuated cylinders, in which a second piston rod is inserted into a locking device. The end of this introduced The piston rod is provided with a ring guide into which locking elements are inserted when locked. The locking elements are prevented by a slide from moving radially outwards. A counter bearing ensures that the piston rod cannot be pulled out. Only when the slide permits radial movement of the locking elements can the piston rod be pulled out again. With such a device, a locking of a piston rod in a very specific position is possible, although not free of play. However, such an arrangement cannot exert an active axial force on the piston rod.
• the invention has for its object to propose a generic device with which it is possible to move a piston rod even under maximum force with precisely controllable speed at least over a small distance and also independently of laser fluctuations. This requirement is to be met without the locking elements used having to run in oil, as is necessary according to EP-A-219 594.
• the device according to the invention it is possible to first move the piston rod (pull rod) to be moved axially over an arbitrarily long path with any force into the cylinder housing, to the extent that the locking elements have been moved radially inwards into the locking position.
• this locking position can be changed further axially, namely by actuating the support means of a further piston between the pull rod and the cylinder housing.
• the piston can be axially displaced in the direction of the cylinder base by means of a pressure medium. A relative movement in the radial direction or with a radial component between the locking elements and the pull rod used does not take place since the locking elements in the locking position bear against the outside against an annular piston which blocks a radial outward movement of the locking elements.
• the pull-in force of the pull rod depends on the pressure acting on the piston, which can be set as desired.
• a major advantage of this design is that a short displacement path can be precisely adjusted under the influence of a high force exerted by the pressure medium.
• the pressure on the piston with its support means can be hydraulic or pneumatic. But it is also possible to use a toggle lever mechanism to move in the direction of the cylinder bottom or against the locking elements and the ring piston.
• the draw-in speed of the drawbar is almost independent of the load and is only a function of the pressure set in each case.
• the device according to the invention is designed as a unit with a pressure-actuated piston-cylinder unit arranged coaxially thereto, in which the piston has a piston rod on both sides, one of which exits to the outside and the other the other Forms pull rod which can be inserted coaxially into the cylinder housing and which is formed with an inclined surface which extends outwards towards the free end and which forms a contact surface for receiving the radially movable locking elements.
• the pressure medium connection which is provided on the side of the piston of the piston-cylinder unit which carries the second piston rod (tie rod), is simultaneously connected to the rest of the pressure medium-operated device in such a way that the pressure medium (Compressed gas) is directed to the front of the piston and pushes it into the unlocking position as soon as the piston-cylinder unit is pressurized in the appropriate sense.
• FIG. 1 a longitudinal section through the device in the structural unit with a piston-cylinder unit before the introduction of the KraiLhubos
• Figure 2 a longitudinal section as in Figure 1 at the beginning of the power stroke
• Figure 3 a longitudinal section as in Figure 1 at the end of the power stroke.
• the piston-cylinder unit is shown with reference number 10.
• a cylinder housing 12 with a cylinder body 14 at the left end can be seen.
• a piston rod 16 projects into the right open end who sits a pull rod 18 stationary.
• the piston rod 16 or pull rod 18 is guided by means of cylindrical elements 20, 22.
• Damping rings 24, 26 are arranged between the elements 20, 22 and the piston rod 16 or pull rod 18, which ensure that the piston piston is in the vicinity of the end position ⁇ speed is automatically throttled and a hard impact on the piston is avoided.
• a further piston (annular piston) 28 is arranged in front of the element 22 coaxially with the pull rod 18.
• the end of the piston 28 directed towards the cylinder base 14 is tubular.
• the piston 28 is sealed on the outside in a conventional manner via seals, not designated in any more detail, but is arranged displaceably in the cylinder housing 12.
• the front end faces of the tubular section are identified by 28a.
• the mandrel 30 if there is no counterforce — is pushed to the right (in the direction of the pull rod 18) until it abuts a stop 36 with an inner collar 34.
• the stop 36 is formed here by the head of a screw fastened in the cylinder base 14.
• An annular piston 38 is arranged between the mandrel 30 and the cylinder housing 12, which can slide on the mandrel 30 and is sealed both against the cylinder housing 12 and against the cylinder surface of the dome 30.
• the annular piston 38 is under the action of a compression spring 40 which is supported on the cylinder base 14.
• the inner diameter of the annular piston 38 widens over an inclined surface 38a, an inner cylindrical surface 38b and an adjoining further inclined surface 38c, which has a truncated cone shape.
• a number of locking elements 42 are supported by the cylindrical outer surface of the dome 30.
• the Verriegelungs ⁇ elements 42 are of a circular ring segments formed un.d lie with an outer inclined surface '42c on the surface Schräg ⁇ 38c of the annular piston 38 at.
• the locking elements 42 bear against the end face 28a of the piston 28, which serve here as a support.
• diusur PusiLiun vorbluibL an I ruiruuin 44 between the locking elements 42 and the cylinder housing 12th
• the pull rod 18 is formed at its left end in the figure with an enlarged collar 46, and the pull rod 18 widens over an inclined surface 18a to the collar 46.
• the front end face 18b of the pull rod 18 bears against the corresponding end face of the dome 30.
• a compressed gas connection 48 is provided, via which the piston rod 16 can be pressurized with compressed gas.
• a further pressurized gas connection 50 is provided in the area of the element 22, the piston rod 16 being able to be moved back in the opposite direction (in the figure: to the right) by means of pressurized gas which is supplied here.
• the pressurized gas can also flow through the space 52 between the tie rod 18 and the piston 28 and a sufficiently dimensionable gap between the circumferential surface of the collar 46 and the inner cylindrical surface of the piston 28 and the free spaces between the Locking elements 42 enter the free space 44 and thus act on the annular piston 38 so that it is driven back against the action of the springs 40 into the position shown in FIG.
• the further pressure medium connection 54 with which the front end face of the annular piston 28 can be acted upon, is of particular importance.
• the pressure medium can be oil or gas; however, it is also possible to arrange a toggle lever mechanism at this point, by means of which the annular piston 28 is mechanically driven in the direction of the cylinder base 14.
• the pressure medium acts against the action of springs 56, which hold the annular piston 28 under constant preload.
• springs 56 instead of the springs 56, other pressure media, such as a fluid, could also be used.
• FIG. 2 shows the device according to FIG. 1 after the compressed gas connection 48 has been actuated.
• the piston rod 16 and with it the pull rod 18 have hereby been pressed in the direction of the cylinder base 14, to the extent that the locking elements 42 slide behind the collar 46 under the radial pressure of the annular piston 38 could.
• the annular piston 38 has moved to the right under the action of the springs 40 and now engages around the locking elements 42 on its outer surface, which bear against the cylinder surface 38b. Movement of the locking elements 42 to the outside is no longer possible.
• the power stroke can now take place with precisely controlled speed, raft and defined length.
• a film cutting knife attached to the free end of the piston rod 16 could be moved from the position shown in FIG. 1 to the position shown in FIG. 2 by the movement of the piston rod 16 in the starting position for the cut.
• pressure medium connection 54 here: pressure oil
• the piston 28 is pressed against the resistance of the springs 56 to the left in the direction of the cylinder bottom 14.
• the speed at which the piston 28 moves depends on the quantity of oil supplied and the oil pressure. Both can be regulated very precisely. Load fluctuations on the piston 28 which occur as reaction forces are only manifested in pressure fluctuations of the hydraulic medium supplied. Speed fluctuations of undesirable size do not occur.
• This position can be maintained by correspondingly maintaining the pressure via the pressure medium connection 54 until another position is desired

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Actuator (AREA)
• Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
• Fluid-Damping Devices (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6837789

Family Applications (1)

Country Status (5)

Cited By (1)

Citations (5)

Family Cites Families (3)

• 1989
  • 1989-04-03 DE DE8904055U patent/DE8904055U1/de not_active Expired
• 1990
  • 1990-04-01 WO PCT/DE1990/000256 patent/WO1990012213A1/de active IP Right Grant
  • 1990-04-01 DE DEDE9000256T patent/DE4090549D2/de not_active Expired - Fee Related
  • 1990-04-01 DE DE9090904773T patent/DE59000489D1/de not_active Expired - Lifetime
  • 1990-04-01 EP EP90904773A patent/EP0466718B1/de not_active Expired - Lifetime
  • 1990-04-01 DK DK90904773T patent/DK0466718T3/da active
  • 1990-04-01 ES ES90904773T patent/ES2035750T3/es not_active Expired - Lifetime

Patent Citations (5)

Non-Patent Citations (1)

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