EP3986674A1 - A device for changing the dynamic stiffness of a gantry or overhung structure - Google Patents

A device for changing the dynamic stiffness of a gantry or overhung structure

Info

Publication number
EP3986674A1
EP3986674A1 EP20756746.2A EP20756746A EP3986674A1 EP 3986674 A1 EP3986674 A1 EP 3986674A1 EP 20756746 A EP20756746 A EP 20756746A EP 3986674 A1 EP3986674 A1 EP 3986674A1
Authority
EP
European Patent Office
Prior art keywords
gantry
ropes
changing
dynamic stiffness
frame
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.)
Pending
Application number
EP20756746.2A
Other languages
German (de)
French (fr)
Inventor
Michael VALÁ EK
Martin NE AS
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.)
Czech Technical University In Prague
Original Assignee
Czech Technical University In Prague
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 Czech Technical University In Prague filed Critical Czech Technical University In Prague
Publication of EP3986674A1 publication Critical patent/EP3986674A1/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/02—Programme-controlled manipulators characterised by movement of the arms, e.g. cartesian coordinate type
    • B25J9/023—Cartesian coordinate type
    • B25J9/026—Gantry-type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/005—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion using electro- or magnetostrictive actuation means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
    • F16F15/03—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using magnetic or electromagnetic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16S—CONSTRUCTIONAL ELEMENTS IN GENERAL; STRUCTURES BUILT-UP FROM SUCH ELEMENTS, IN GENERAL
    • F16S3/00—Elongated members, e.g. profiled members; Assemblies thereof; Gratings or grilles
    • F16S3/04—Elongated members, e.g. profiled members; Assemblies thereof; Gratings or grilles designed for being joined to similar members in various relative positions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M15/00—Testing of engines
    • G01M15/14—Testing gas-turbine engines or jet-propulsion engines
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M7/00—Vibration-testing of structures; Shock-testing of structures
    • G01M7/02—Vibration-testing by means of a shake table
    • G01M7/022—Vibration control arrangements, e.g. for generating random vibrations
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B5/00—Anti-hunting arrangements
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B6/00—Internal feedback arrangements for obtaining particular characteristics, e.g. proportional, integral or differential
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05G—CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY
    • G05G3/00—Controlled members; Assemblies or arrangements thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2228/00—Functional characteristics, e.g. variability, frequency-dependence
    • F16F2228/06—Stiffness
    • F16F2228/066—Variable stiffness

Definitions

  • the invention concerns a device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure with a gantry or an upright stand slidingly guided along a frame, whereas the gantry or upright stand is movably connected to at least one other movable element.
  • Stiffness along with vibration absorption is one of the most important construction requirements. High dynamic stiffness together with high absorption of structure vibrations is extremely important. The stiffness along with vibration absorption is crucial for reducing the oscillation of structures and increasing the accuracy of positioning and motion of machines.
  • the stiffness along with vibration absorption is crucial for reducing the oscillation of structures and increasing the accuracy of positioning and motion of machines.
  • the dynamic stiffness consists of the static stiffness and vibration absorption of the structure.
  • the stiffness increases passively by enlarging section profiles of load-carrying elements of a structure, by using varied materials and by various structural modifications through extensive optimizations. Especially preferable is a combination of materials with a high stiffness and low density, leading to a low weight of the resulting structure, and appropriate structural modifications.
  • a tube-shaped beam using carbon composites of high modulus carbon fibers and polymer binder whereas their maximum material absorption can be achieved by integrating absorbing layers of a material with very high absorption into the inner structure of the composite.
  • Absorption of vibration or deformation can be mostly influenced directly by an active mechatronic solution, the stiffness can be influenced only in an indirect way.
  • Active elements are placed into the structure of the construction, mostly piezoelectric actuators, but these can also be electrodynamic, magnetostrictive, hydraulic or magnetorheologic, or in some case ionic polymers as well.
  • Active elements can be placed into construction elements, bars of lattice-work structure, on a surface of beams or shells as piezoelectric actuator patches or solid active layers, into actuators of ropes connecting parts of a structure or can be implemented as fixing elements of additional substances.
  • Mechanisms of the controlled absorption of vibrations are based on additional absorption, vibration isolation, vibration compensation or vibration absorption. Furthermore we differentiate between active (with possible energy supply) and semi-active (with energy dissipation only) control of vibration absorption. Applications are widespread from wings of airplanes, constructions of antennas, radars and telescopes and boring bars to constructions of rope bridges.
  • active solutions include a concept of the mechatronic stiffness (PV 2006-123/CZ patent 304667) that increases (in case of need even modifies or decreases) the dynamic stiffness of structures, thus also increasing the stiffness to weight ratio of a structure leading to increasing its own frequencies.
  • This concept with an actuator of a controlled force source removes the abovementioned problems on a large scale. For its practical realization a compact solution is needed that would not enlarge and increase a weight of solutions existing up to now.
  • a tube in a tube is an advantageous solution.
  • a compact solution has been created where an actuator has been placed outside the tube using a tow-bar.
  • the aim of this invention is to create a solution of such a device for changing the dynamic stiffness (stiffness and vibration absorption) of a structure with variable dimensions when moving, especially movable gantry and overhanging structures.
  • Ropes are firmly fixed to the gantry or upright stand through one end and attached to a pulley with an actuator through the second end, or ropes are firmly fixed to the gantry or upright stand through one end and are guided over at least two pulleys without actuators to some movable element of the structure, whereas at least two pulleys without actuators are arranged on the opposite side of the movable element of the structure. Possibly ropes are arranged between a platform sliding along a stacker upright stand and a carriage sliding along a frame. Ropes can be connected to an auxiliary actuator between their ends.
  • the structure is equipped with a sensor of position or acceleration of its movable elements.
  • Figures 1 to 14 show a schematic depiction of a possible embodiment of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry or overhanging structure.
  • FIG. 1 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry-type structure.
  • This is a machining device with gantry ⁇ moving along frame 8.
  • Slide 3 moves along gantry 1; headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom.
  • Gantry 1 is guided along frame 8, which represents a supporting element for gantry 1 here, and gantry I is connected to frame 8 through ropes 10.
  • Ropes 10 allow respecting a change in gantry I position on frame 8 caused by its move along frame 8.
  • Ropes 10 can transfer tensile forces only, so preferably a couple of ropes 10 are used, whereas one rope 10 is guided in the opposite direction than the second rope 10.
  • the arrangement of attachment of ropes IQ, and possibly of their actuators, to a supporting element (to frame 8 here) is described in more details in Figures 8-14 below.
  • Figure 2 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry-type structure in an alternative embodiment.
  • This is a machining device with gantry 1 consisting only of a cross rail moving along frame 8.
  • Slide 3 moves along gantry I; headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom.
  • Gantry ⁇ is guided along frame 8, which represents a frame structure supporting element for gantry 1 here, and gantry l is connected to frame 8 through ropes 10.
  • Ropes 10 are guided over pulleys IT attached to frame 8 to pulleys 12 with an actuator attached to frame 8.
  • Ropes 10 allow respecting a change in gantry i position on frame 8 caused by its move along frame 8. Two couples of ropes 10 are used here as well. The arrangement of attachment of ropes 10, and possibly of their actuators, to a supporting element (to frame 8 here) is described in more details in Figures 8-14 below.
  • FIG 3 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging headstock 2 (the same as in Figs. 1 and 2).
  • This is a machining device with gantry 1 moving along frame 8.
  • Slide 3 moves along gantry 1; overhanging headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom.
  • Headstock 2 is attached to gantry i, which represents a supporting element for headstock 2 here, through ropes JO.
  • Ropes K) allow respecting a change in a position of the top of headstock 2 caused by a move of headstock 2 and by slide 3 along gantry L
  • Ropes JO are arranged in couples. The arrangement of attachment of ropes JO, and possibly of their actuators, to a supporting element (to gantry J, here) is described in more details in Figures 8-14 below.
  • Fig.4 shows a schematic depiction of the device from Fig. 3 in a front projection.
  • Fig. 5 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging headstock 2.
  • This is a machining device with gantry ⁇ moving along frame 8.
  • Slide 3 moves along gantry 1 ; overhanging headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom.
  • Headstock 2 is attached to slide 3, which represents a supporting element for headstock 2 here, through ropes JO.
  • Ropes 10 allow respecting a change in a position of headstock 2 towards slide 3 caused by a move of headstock 2.
  • Ropes 10 are arranged in couples.
  • Fig. 6 shows a schematic depiction of the device from Fig. 5 in a front projection.
  • Fig. 7 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging upright stand 5 of a stacker along which platform 6 moves.
  • This is a storehouse (rack) stacker on a travel carriage 4 with upright stand 5 of a stacker travelling on frame 8. Further, platform 6 moves along upright stand 5 of the stacker, carrying a pallet or another object to a required position given by a travel of carriage 4 and platform 6.
  • Upright stand 5 of the stacker is flightly attached to carriage 4 and platform 6 is flightly attached to upright stand 5 of the stacker.
  • Platform 6 is attached through upright stand 5 of the stacker to carriage 4 using ropes 10; carriage 4 represents here a supporting element for upright stand 5 of the stacker and platform 6.
  • Ropes 10 allow respecting a variable position of platform 6 with regard to the bottom of upright stand 5 of the stacker caused by a movement of platform 6 along upright stand 5 of the stacker.
  • Ropes 10 are arranged in couples. The arrangement of attachment of ropes 10, and possibly of their actuators, to a supporting element (to carriage 4 here) is described in more details in Figures 8-14 below.
  • Fig. 8 shows a schematic depiction of ropes FO guided from gantry I to a supporting element (being frame 8 here) and the arrangement of their actuators.
  • Ropes 10 are guided to pulleys 12 fitted with actuators Ml and M2.
  • Pulleys 12 with actuators Ml and M2 are attached to frame 8.
  • Gantry 1 is equipped with sensor 9 of a position of gantry 1 of frame 8 or of acceleration of a motion of gantry T
  • the signal from sensor 9 is used for the feedback control of actuators Ml and M2, and due to this also of forces in ropes 10; it is used both for the control of the dynamic stiffness and/or vibration absorption of a gantry structure and/or of a position of the end of gantry ⁇ .
  • This embodiment corresponds particularly to the device in Fig. 1.
  • This embodiment corresponds also to the device in Figs. 3 and 4, if in Fig. 8 gantry l has been replaced by headstock 2 and frame 8 by gantry L
  • this embodiment corresponds also to the device in Figs. 5 and 6, if in Fig. 8 gantry 1 has been replaced by headstock 2 and frame 8 by slide 3.
  • this embodiment corresponds to the device in Fig. 7, if in Fig. 8 gantry 1 has been replaced by platform 6 and frame 8 by travel carriage 4.
  • Fig. 9 shows a schematic depiction of ropes 10 guided from gantry l to a supporting element (being frame 8 here) and the arrangement of their actuators for the device in Fig. 2.
  • Ropes 10 are guided over pulleys IT attached to frame 8 to pulleys 12 fitted with actuators Ml and M2.
  • Pulleys 12 with actuators Ml and M2 are attached to frame 8.
  • Gantry ⁇ is equipped with sensor 9 of a position of gantry 1 of frame 8 or of acceleration of a motion of gantry I.
  • the signal from sensor 9 is used for the feedback control of actuators Ml and M2, and due to this also of forces in ropes 10; it is used both for the control of the dynamic stiffness and/or vibration absorption of a gantry structure and/or of a position of the end of gantry T
  • the force in ropes 10 can be used for their passive pre-stressing according to their position.
  • the schematic depiction of the arrangement of ropes 10 in Fig. 10 - reeling or unreeling of ropes 10 to/from pulleys 11 without actuators does not occur when changing a position of gantry 1, ropes 10 are only guided over these pulleys 1 L
  • the arrangement of pulleys IT without actuators in Fig. 10 is possible on the left and on the right side, both the arrangements can be used for one gantry structure.
  • An advantage is the invariable length of ropes K) even when gantry 1 is moving.
  • this arrangement of ropes 10 can be preferably used for the device in Fig. 2.
  • FIG. 11 A practical solution of a similar arrangement of ropes 10 in Fig. 10 is depicted in Fig. 11.
  • a length of ropes 10 in sections from their ends to the first pulley IT without an actuator is variable when gantry 1 moves along frame 8 but an adverse effect of this variability can be compensated by pre-stressing ropes 10 or by connecting the left and right arrangement of pulleys IT without actuators into one device, as schematically depicted in Fig. 12.
  • auxiliary actuators 13 are advisable to be used for a compensation of the variable length of ropes 10, as schematically depicted in Fig. 13.
  • auxiliary actuators 13 shorten or lengthen ropes If), so that their prestress is constant regardless of a position of gantry 1 on frame 8 according to this position.
  • auxiliary actuators 3 can be used even for the active feedback control as in Fig. 8, but in comparison with Fig. 8 ropes 10 need not to be reeled onto pulleys.
  • This can be solved by connecting the left and right arrangement of auxiliary actuators 13 into one device. Such a connected arrangement is schematically depicted in Fig. 14.
  • This device can use auxiliary actuators 13 only for keeping the constant prestress of ropes 10 or also for the active feedback control, in which case, however, sensor 9 needs to be placed as in Fig. 8; in this Figure sensor 9 is not shown.
  • Figs. 8-14 show only the arrangement of attachment of ropes 10, and possibly of their actuators, to the supporting element for gantry structure L
  • This solution can also be accordingly used for overhanging slide-out structures depicted in Figs. 3-6 or for overhanging platform 6 of the stacker depicted in Fig. 7.
  • ropes 10 transfer tensile forces only, ropes 10 are arranged in couples in order to act in both the directions because the tension for one rope of the couple means the compression for the second rope of the couple.
  • An advantage of the invention is a possibility to achieve the variable dynamic stiffness of the structure due to ropes, thus the additional static stiffness and/or the additional vibration absorption depending on a position of the movable structure.
  • All the described variants of the arrangement of ropes can be combined one with another.
  • the number of ropes can vary.
  • Particular control elements of the device are preferably controlled by a computer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Electromagnetism (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical & Material Sciences (AREA)
  • Robotics (AREA)
  • Vibration Prevention Devices (AREA)
  • Auxiliary Devices For Machine Tools (AREA)

Abstract

The invention concerns a device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure with gantry (1) or upright stand (5) slidingly moving along frame (8), whereas gantry (1) or upright stand (5) is movably connected to at least one other movable element, which lies in that between frame (8) and gantry (1) or upright stand (5), or between two movable parts of the structure, there are ropes (10) arranged with at least one end fixed to the first part and at least one second end fixed to the second part of the gantry or overhanging structure. At least one rope (10) is guided from gantry (1) in the direction of its motion and at least one rope is guided from gantry (10) against the direction of its motion.

Description

A device for changing the dynamic stiffness of a gantry or overhanging structure
Technical Field of the Invention
The invention concerns a device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure with a gantry or an upright stand slidingly guided along a frame, whereas the gantry or upright stand is movably connected to at least one other movable element.
State-of-the-art
Stiffness along with vibration absorption is one of the most important construction requirements. High dynamic stiffness together with high absorption of structure vibrations is extremely important. The stiffness along with vibration absorption is crucial for reducing the oscillation of structures and increasing the accuracy of positioning and motion of machines. We differentiate between the (static) stiffness given by the ratio of the static load and the occurred deformation of a structure and the dynamic stiffness given by the ratio of the dynamic load and the occurred time-variable deformation (oscillation) of a structure. The dynamic stiffness consists of the static stiffness and vibration absorption of the structure.
The stiffness increases passively by enlarging section profiles of load-carrying elements of a structure, by using varied materials and by various structural modifications through extensive optimizations. Especially preferable is a combination of materials with a high stiffness and low density, leading to a low weight of the resulting structure, and appropriate structural modifications.
In mechanical engineering more and more means are sought to achieve as high stiffness and as effective mechanical absorption of oscillation as possible for structures and parts performing motions with a high acceleration. These are in particular structural elements such as beams of manufacturing machinery, manipulators and robots, where there are the most urgent requirements for the utmost static as well as dynamic stiffness, the lowest temperature deformations and the long-term stiffness stability at own weight as low as possible. The requirements are based on the economical need for ever increasing productivity of engineering production, accuracy of products and their reproducibility. There are many solutions already applied. As for passive solutions, there are lattice-work structures, thin-walled structures, rope structures etc. using titanium, aluminum or composite materials. There is an example: a tube-shaped beam using carbon composites of high modulus carbon fibers and polymer binder, whereas their maximum material absorption can be achieved by integrating absorbing layers of a material with very high absorption into the inner structure of the composite. Absorption of vibration or deformation can be mostly influenced directly by an active mechatronic solution, the stiffness can be influenced only in an indirect way. Active elements are placed into the structure of the construction, mostly piezoelectric actuators, but these can also be electrodynamic, magnetostrictive, hydraulic or magnetorheologic, or in some case ionic polymers as well. Active elements can be placed into construction elements, bars of lattice-work structure, on a surface of beams or shells as piezoelectric actuator patches or solid active layers, into actuators of ropes connecting parts of a structure or can be implemented as fixing elements of additional substances.
Mechanisms of the controlled absorption of vibrations are based on additional absorption, vibration isolation, vibration compensation or vibration absorption. Furthermore we differentiate between active (with possible energy supply) and semi-active (with energy dissipation only) control of vibration absorption. Applications are widespread from wings of airplanes, constructions of antennas, radars and telescopes and boring bars to constructions of rope bridges.
In general, structures are of infinite number of degrees of freedom, so structures with the active control of vibration absorption are in a danger of occurrence of the effect of destabilization by energy overflow, the so called spillover. It has been shown that this danger is not a threat if the collocated control of vibration absorption is applied. In most cases the dynamic stiffness is needed in a part of the structure that cannot be directly and in the shortest way connected to a frame, supported by a frame, in order to increase its stiffness. Another problem is that active elements placed in a structure (for example on a tube-shaped beam wall) have a low transfer of action of force in the direction of the structure deformation due to the external load force, so active elements have to apply a strong force to compensate for a disproportionately lower load forces. Therefore it is difficult to find adequately strong actuators. Existing mechanisms for the control of vibration absorption act mostly on relative coordinates of a structure, or for example by means of an active rope from a frame. An open issue is whether the analogical effect can be lead from a frame also into inaccessible parts of a structure, influencing the structure dynamic stiffness directly using feedback control.
Further, active solutions include a concept of the mechatronic stiffness (PV 2006-123/CZ patent 304667) that increases (in case of need even modifies or decreases) the dynamic stiffness of structures, thus also increasing the stiffness to weight ratio of a structure leading to increasing its own frequencies. This concept with an actuator of a controlled force source removes the abovementioned problems on a large scale. For its practical realization a compact solution is needed that would not enlarge and increase a weight of solutions existing up to now. A tube in a tube is an advantageous solution. Also, a compact solution has been created where an actuator has been placed outside the tube using a tow-bar.
However, the solutions described above mostly concern unmovable structures. Even if a robot arm is moving, the own arm has constant dimensions. An open issue is a change in the stiffness and vibration absorption in structures with time-variable dimensions when they are moving. Such structures are often overhanging.
The aim of this invention is to create a solution of such a device for changing the dynamic stiffness (stiffness and vibration absorption) of a structure with variable dimensions when moving, especially movable gantry and overhanging structures.
Subject Matter of the Invention
A subject matter of a device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure with a gantry or an upright stand sliding along a frame, whereas the gantry or upright stand is movably connected to at least one other movable element, according to this invention lies in that between the frame and the gantry or upright stand, or between two movable parts of the structure, there are ropes arranged with at least one end fixed to the first part and at least one second end fixed to the second part of the gantry or overhanging structure. At least one rope is guided from the gantry in the direction of its motion and at least one rope is guided from the gantry against the direction of its motion. Ropes are firmly fixed to the gantry or upright stand through one end and attached to a pulley with an actuator through the second end, or ropes are firmly fixed to the gantry or upright stand through one end and are guided over at least two pulleys without actuators to some movable element of the structure, whereas at least two pulleys without actuators are arranged on the opposite side of the movable element of the structure. Possibly ropes are arranged between a platform sliding along a stacker upright stand and a carriage sliding along a frame. Ropes can be connected to an auxiliary actuator between their ends. The structure is equipped with a sensor of position or acceleration of its movable elements.
Overview of Figures in Drawings
Figures 1 to 14 show a schematic depiction of a possible embodiment of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry or overhanging structure.
Examples of Embodiments of the Invention
Figure 1 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry-type structure. This is a machining device with gantry \ moving along frame 8. Slide 3 moves along gantry 1; headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom. Gantry 1 is guided along frame 8, which represents a supporting element for gantry 1 here, and gantry I is connected to frame 8 through ropes 10. Ropes 10 allow respecting a change in gantry I position on frame 8 caused by its move along frame 8. Ropes 10 can transfer tensile forces only, so preferably a couple of ropes 10 are used, whereas one rope 10 is guided in the opposite direction than the second rope 10. The arrangement of attachment of ropes IQ, and possibly of their actuators, to a supporting element (to frame 8 here) is described in more details in Figures 8-14 below.
Figure 2 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving gantry-type structure in an alternative embodiment. This is a machining device with gantry 1 consisting only of a cross rail moving along frame 8. Slide 3 moves along gantry I; headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom. Gantry \ is guided along frame 8, which represents a frame structure supporting element for gantry 1 here, and gantry l is connected to frame 8 through ropes 10. Ropes 10 are guided over pulleys IT attached to frame 8 to pulleys 12 with an actuator attached to frame 8. Ropes 10 allow respecting a change in gantry i position on frame 8 caused by its move along frame 8. Two couples of ropes 10 are used here as well. The arrangement of attachment of ropes 10, and possibly of their actuators, to a supporting element (to frame 8 here) is described in more details in Figures 8-14 below.
Figure 3 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging headstock 2 (the same as in Figs. 1 and 2). This is a machining device with gantry 1 moving along frame 8. Slide 3 moves along gantry 1; overhanging headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom. Headstock 2 is attached to gantry i, which represents a supporting element for headstock 2 here, through ropes JO. Ropes K) allow respecting a change in a position of the top of headstock 2 caused by a move of headstock 2 and by slide 3 along gantry L Ropes JO are arranged in couples. The arrangement of attachment of ropes JO, and possibly of their actuators, to a supporting element (to gantry J, here) is described in more details in Figures 8-14 below.
Fig.4 shows a schematic depiction of the device from Fig. 3 in a front projection.
Fig. 5 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging headstock 2. This is a machining device with gantry \ moving along frame 8. Slide 3 moves along gantry 1 ; overhanging headstock 2 throwing out from slide 3 is fitted with a tilting head with a machining tool in the bottom. Headstock 2 is attached to slide 3, which represents a supporting element for headstock 2 here, through ropes JO. Ropes 10 allow respecting a change in a position of headstock 2 towards slide 3 caused by a move of headstock 2. Ropes 10 are arranged in couples. The arrangement of attachment of ropes JO, and possibly of their actuators, to a supporting element (to slide 3 here) is described in more details in Figures 8-14 below. Fig. 6 shows a schematic depiction of the device from Fig. 5 in a front projection.
Fig. 7 shows a schematic depiction of a device for changing the dynamic stiffness and/or vibration absorption of a moving structure of an overhanging upright stand 5 of a stacker along which platform 6 moves. This is a storehouse (rack) stacker on a travel carriage 4 with upright stand 5 of a stacker travelling on frame 8. Further, platform 6 moves along upright stand 5 of the stacker, carrying a pallet or another object to a required position given by a travel of carriage 4 and platform 6. Upright stand 5 of the stacker is flightly attached to carriage 4 and platform 6 is flightly attached to upright stand 5 of the stacker. Platform 6 is attached through upright stand 5 of the stacker to carriage 4 using ropes 10; carriage 4 represents here a supporting element for upright stand 5 of the stacker and platform 6. Ropes 10 allow respecting a variable position of platform 6 with regard to the bottom of upright stand 5 of the stacker caused by a movement of platform 6 along upright stand 5 of the stacker. Ropes 10 are arranged in couples. The arrangement of attachment of ropes 10, and possibly of their actuators, to a supporting element (to carriage 4 here) is described in more details in Figures 8-14 below.
Fig. 8 shows a schematic depiction of ropes FO guided from gantry I to a supporting element (being frame 8 here) and the arrangement of their actuators. Ropes 10 are guided to pulleys 12 fitted with actuators Ml and M2. Pulleys 12 with actuators Ml and M2 are attached to frame 8. Gantry 1 is equipped with sensor 9 of a position of gantry 1 of frame 8 or of acceleration of a motion of gantry T The signal from sensor 9 is used for the feedback control of actuators Ml and M2, and due to this also of forces in ropes 10; it is used both for the control of the dynamic stiffness and/or vibration absorption of a gantry structure and/or of a position of the end of gantry \ . This embodiment corresponds particularly to the device in Fig. 1. This embodiment corresponds also to the device in Figs. 3 and 4, if in Fig. 8 gantry l has been replaced by headstock 2 and frame 8 by gantry L Further, this embodiment corresponds also to the device in Figs. 5 and 6, if in Fig. 8 gantry 1 has been replaced by headstock 2 and frame 8 by slide 3. And finally this embodiment corresponds to the device in Fig. 7, if in Fig. 8 gantry 1 has been replaced by platform 6 and frame 8 by travel carriage 4.
Fig. 9 shows a schematic depiction of ropes 10 guided from gantry l to a supporting element (being frame 8 here) and the arrangement of their actuators for the device in Fig. 2. Ropes 10 are guided over pulleys IT attached to frame 8 to pulleys 12 fitted with actuators Ml and M2. Pulleys 12 with actuators Ml and M2 are attached to frame 8. Gantry \ is equipped with sensor 9 of a position of gantry 1 of frame 8 or of acceleration of a motion of gantry I. The signal from sensor 9 is used for the feedback control of actuators Ml and M2, and due to this also of forces in ropes 10; it is used both for the control of the dynamic stiffness and/or vibration absorption of a gantry structure and/or of a position of the end of gantry T
Besides the active feedback control of force in ropes 10, the force in ropes 10 can be used for their passive pre-stressing according to their position. As for the schematic depiction of the arrangement of ropes 10 in Fig. 10 - reeling or unreeling of ropes 10 to/from pulleys 11 without actuators does not occur when changing a position of gantry 1, ropes 10 are only guided over these pulleys 1 L The arrangement of pulleys IT without actuators in Fig. 10 is possible on the left and on the right side, both the arrangements can be used for one gantry structure. An advantage is the invariable length of ropes K) even when gantry 1 is moving. Thus, this arrangement of ropes 10 can be preferably used for the device in Fig. 2.
However, attaching the left and right upper pulley JT without actuators is advantageous only in a case the device directly includes a frame structure as in Fig. 2 because pulleys IT can be attached in space only with difficulties.
A practical solution of a similar arrangement of ropes 10 in Fig. 10 is depicted in Fig. 11. A length of ropes 10 in sections from their ends to the first pulley IT without an actuator is variable when gantry 1 moves along frame 8 but an adverse effect of this variability can be compensated by pre-stressing ropes 10 or by connecting the left and right arrangement of pulleys IT without actuators into one device, as schematically depicted in Fig. 12.
If a travel of gantry i along frame 8 is longer, then auxiliary actuators 13 are advisable to be used for a compensation of the variable length of ropes 10, as schematically depicted in Fig. 13. Here auxiliary actuators 13 shorten or lengthen ropes If), so that their prestress is constant regardless of a position of gantry 1 on frame 8 according to this position. However, auxiliary actuators 3 can be used even for the active feedback control as in Fig. 8, but in comparison with Fig. 8 ropes 10 need not to be reeled onto pulleys. This can be solved by connecting the left and right arrangement of auxiliary actuators 13 into one device. Such a connected arrangement is schematically depicted in Fig. 14. This device can use auxiliary actuators 13 only for keeping the constant prestress of ropes 10 or also for the active feedback control, in which case, however, sensor 9 needs to be placed as in Fig. 8; in this Figure sensor 9 is not shown.
Figs. 8-14 show only the arrangement of attachment of ropes 10, and possibly of their actuators, to the supporting element for gantry structure L This solution can also be accordingly used for overhanging slide-out structures depicted in Figs. 3-6 or for overhanging platform 6 of the stacker depicted in Fig. 7. As ropes 10 transfer tensile forces only, ropes 10 are arranged in couples in order to act in both the directions because the tension for one rope of the couple means the compression for the second rope of the couple.
An advantage of the invention is a possibility to achieve the variable dynamic stiffness of the structure due to ropes, thus the additional static stiffness and/or the additional vibration absorption depending on a position of the movable structure.
All the described variants of the arrangement of ropes can be combined one with another. The number of ropes can vary. Particular control elements of the device are preferably controlled by a computer.

Claims

PATENT CLAIMS
1. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure with gantry (1) or upright stand (5) slidingly moving along frame (8), whereas gantry (1) or upright stand (5) is movably connected to at least one other movable element, characterized in that between frame (8) and the gantry (1) or upright stand (5), or between two movable parts of the structure there are ropes (10) arranged with at least one end fixed to the first part and at least one second end fixed to the second part of the gantry or overhanging structure.
2. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to Claim 1, characterized in that least one rope (10) is guided from gantry (1) in the direction of its motion and at least one rope is guided from gantry (1) against the direction of its motion.
3. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to Claim 1 or 2, characterized in that ropes (10) are firmly fixed to gantry (1) or upright stand (5) through one end and attached to pulley (12) with an actuator through the second end.
4. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to Claim 1 or 2, characterized in that ropes (10) are firmly fixed to gantry (1) or upright stand (5) through one end and are guided over at least two pulleys (11) without actuators to some movable element of the structure, whereas at least two pulleys (11) without actuators are arranged on the opposite side of the movable element of the structure.
5. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to Claim 1 or 2, characterized in that ropes (10) are arranged between platform (6) sliding along upright stand (5) of a stacker and carriage (4) sliding along frame (8).
6. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to aforementioned Claim 1 to 5, characterized in that ropes (10) are between their ends connected to auxiliary actuator (13).
7. A device for changing the dynamic stiffness and/or vibration absorption of a gantry or overhanging structure according to any aforementioned Claim 1 to 5, characterized in that the structure is equipped with sensor (9) of a position or acceleration of its movable elements.
EP20756746.2A 2019-06-19 2020-06-02 A device for changing the dynamic stiffness of a gantry or overhung structure Pending EP3986674A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CZ2019-387A CZ2019387A3 (en) 2019-06-19 2019-06-19 A device for changing the dynamic stiffness of a gantry or overhung structure
PCT/CZ2020/000022 WO2020253892A1 (en) 2019-06-19 2020-06-02 A device for changing the dynamic stiffness of a gantry or overhung structure

Publications (1)

Publication Number Publication Date
EP3986674A1 true EP3986674A1 (en) 2022-04-27

Family

ID=69583152

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20756746.2A Pending EP3986674A1 (en) 2019-06-19 2020-06-02 A device for changing the dynamic stiffness of a gantry or overhung structure

Country Status (3)

Country Link
EP (1) EP3986674A1 (en)
CZ (1) CZ2019387A3 (en)
WO (1) WO2020253892A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111993464B (en) * 2020-08-14 2024-01-23 华南理工大学 Vibration testing device and method for spring coupling rotation multi-body mechanical arm system

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003245879A (en) * 2002-02-25 2003-09-02 Takeshi Yanagisawa Overhead travelling unit
US8029710B2 (en) * 2006-11-03 2011-10-04 University Of Southern California Gantry robotics system and related material transport for contour crafting
JP4552129B2 (en) * 2005-02-01 2010-09-29 清水建設株式会社 Tense grid structure
CZ304667B6 (en) * 2006-02-27 2014-08-27 ÄŚVUT v Praze - Fakulta strojnĂ­ Method of and apparatus for change in rigidity of mechanical structures
CN112207585A (en) * 2014-05-30 2021-01-12 J·D·佩恩 Positioning system
CN205133064U (en) * 2015-11-24 2016-04-06 林德（中国）叉车有限公司 A portal vibration damper for vertical lift fork truck
JP2017122372A (en) * 2016-01-08 2017-07-13 株式会社Ihi Rope connection vibration control structure
CN106270592B (en) * 2016-09-21 2018-05-25 哈尔滨理工大学 A kind of intelligent vibration damping boring bar and its vibration-reducing control method
CN107859709B (en) * 2017-11-06 2019-05-07 清华大学 A kind of overlength scale flexible structure active vibration-repressing device based on rope parallel architecture
CN108502724B (en) * 2018-03-30 2019-08-16 山东建筑大学 Automatic adjusument crane arm turns round dynamic stiffness to eliminate the method and system of swing
CN109211502B (en) * 2018-08-06 2021-08-06 上海大学 Variable-load flexible cantilever beam vibration active control experiment system and experiment method

Also Published As

Publication number Publication date
CZ308208B6 (en) 2020-02-26
WO2020253892A1 (en) 2020-12-24
CZ2019387A3 (en) 2020-02-26

Similar Documents

Publication Publication Date Title
FI123784B (en) Arrangement to dampen the swinging of the loading member in the crane
JP4195497B2 (en) Stage equipment
CN103267210A (en) Six-freedom-degree parallel pointing platform
EP3986674A1 (en) A device for changing the dynamic stiffness of a gantry or overhung structure
US10139617B2 (en) Reaction compensated steerable platform
WO2014053528A1 (en) Vessel with system for transferring persons or goods
WO2021071407A1 (en) A device for supporting a load
JP5610231B2 (en) Goods storage shelf
CN117279826A (en) Damping system for a cab of a mobile work machine
CN212080022U (en) Three-dimensional vibration isolation table with active control
JP2002158274A (en) Positioning device
JP7090006B2 (en) Seismic isolation device
KR101705154B1 (en) Flexure hinge-based fine stage for vertical planar 3-DOF motion with high load capacity
JP4585018B2 (en) Stage equipment
JP4964853B2 (en) Stage equipment
CZ33442U1 (en) A device for changing the dynamic stiffness of a gantry or overhanging structure
CZ2015690A3 (en) Device to change rigidity of mechanical constructions
CN103177774B (en) Flexible micrometric and angular displacement piezoelectric actuating platform with two degrees of freedom
JPH03219141A (en) Active damping base
KR101787431B1 (en) Linear structure for transferring displacement and 1-dimensional and 3-dimensional fine scanner using the same
JP4628776B2 (en) Support structure for telescopic arm of transfer machine
RU201218U1 (en) VIBRATION MECHANISM
JP7169224B2 (en) damper device
JP6279345B2 (en) Traveling cargo handling equipment
CN116953870B (en) Six-degree-of-freedom adjustment and dynamic stabilization platform

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20211220

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20240220