CN208451623U - A kind of variation rigidity complaisant grasping device - Google Patents

Abstract

The utility model discloses a kind of variation rigidity complaisant grasping devices, and including two sliding blocks being slidably arranged in linear guide, sliding block is by an open and close movement motor driven and can make relatively close and separate movement.Each sliding block is connected with one for grabbing the clamping jaw of operation by variation rigidity flexible parallel mechanism, and variation rigidity flexible parallel mechanism is by a stiffness equivalent motor driven to adjust its rigidity.Parallel clamping displacement of the clamping jaw on open and close movement direction is controlled by open and close movement motor driven in working condition；By stiffness equivalent motor driven, clamping rigidity of the clamping jaw in open and close movement is controlled.The utility model can continuously change the clamping rigidity on its open and close movement direction, adapt to the clamping operation to different shape, different quality object, the end effector that can be used as robot is particularly suitable for the fields such as operation operation, the precision assembly in unstructured moving grids.

Description

A kind of variation rigidity complaisant grasping device

Technical field

The utility model relates to the end executive devices for robot field, and in particular to a kind of variation rigidity complaisant grasping Device.

Background technique

In recent years, more and more machine person to person appear in together works in the workshop of factory, this namely institute " man-machine collaboration " scene of meaning；However, during this process, must be sent out between people, robot and extraneous unstructured moving grids Raw inevitably collision, therefore, safety will become the important performance indexes of next-generation robot.Since robot end holds Row device is machine person to person and the unique interface that objects outside directly contacts, therefore, consider emphatically end effector of robot this The safety of a key components and parts is most important.

For the angle for executing crawl and fittage, end effector of robot is broadly divided into rigid holder, soft Property four major class of clamper, software clamper and multi-finger clever hand.

Traditional rigid holder is mainly for the purpose of it can clamp object, to limit the attribute of its clamped object It is only hard objects.Although male gram of famous fixture company SCHUNK commercially produces a series of rigid holders, Intricately crawl work can equally be executed and be used for man-machine collaboration, but its accurate actuation techniques and sensor of valuableness etc. It is often lower that induction element largely results in its cost performance.

Flexible retainer is a kind of clamper based on compliant mechanism, in the scientific research process of early period, due to flexibility The deformation of mechanism is small, precision is high and integrated design without friction, without assembly problem the advantages that, be often designed to miniature clamping Device is for needing accurate operation, the operation of precision assembly and semicon industry field.Although it can by the design of cleverly structure To realize variation rigidity function, however the clamper based on single flexible mechanism branched configuration, during clamping operation, there are tired The labor service life is low, chucking power is small, can not complete parallel clamping operation operation the shortcomings that, there are also when its under unstructured moving grids into When row clamping operation, vulnerable to external interference, it is impossible to ensure that during its clamping operation clamping jaw stability, to cause it The problem of system stability and fluency difference.

Software clamper is very powerful and exceedingly arrogant focus in current sphere of learning, such as: being based on Jamming principle, base In a series of software handgrips etc. of SMA, SMP driving principle, they why the concern by more scholars, both because it belonged to The soft robot field in forward position, also due to the breakthrough of a new generation's science and technology such as 3D printing, intellectual material driving allows it to possess The advantages that manufacturing cost is low, noiseless, stiffness variable, PLC technology, however due to its flexible freedom degree and material stiffness Limitation, stability during grasping and grasping precision receive certain influence, while its variation rigidity response speed Often very slow and variation rigidity range is smaller, this equally limits it to by the adaptive ability of grabbing object.

According to driving method, Dextrous Hand is broadly divided into full driving Dextrous Hand and under-actuated delicacy hand, complete to drive Dextrous Hand most Successful commercially produced product is the Shadow robot delicate of company of robot of Britain, but since its structure is complicated, thus It causes its system complex and volume is often huge, to cause its manufacturing cost expensive；The most successful quotient of under-actuated delicacy hand Industry product is the robot gripper of Canadian Robotiq company, although its cleverly driving structure, this greatly increases it Adaptive ability, however for the end effector mechanism of such a under-actuated systems, its statics and dynamics problem Urgent need to resolve at present, at the same its manufacturing cost compared to clamper for, it is still a little expensive.

In conclusion having in view of grasping operation and the operation operation in precision assembly field in unstructured moving grids There is an urgent need to not only can guarantee safety during clamping operation, but also can pass through its flexibility with the clamper of power control function And the characteristic of flexibility guarantees the success rate of clamping operation.But have the rigid holder of complicated and high-accuracy induction element past Expensive toward manufacturing cost, cost performance is low and operating efficiency is low；Although flexible retainer class end effector both has flexible machine The advantages of structure, can also realize the function of its variation rigidity by dexterously designing, but since it is based on single flexible mechanism Lateral buckling instability problem caused by the configuration of branch hunt effect existing during clamping object is still deposited , while it not can guarantee and clamps object in parallel always during clamping operation, this phenomenon is for certain high-accuracy operations Its success rate is often reduced for job task, in addition its there is also system stability and fluency problems；Software clamper class Although it is simple to manufacture, is at low cost end effector, for precision assembly and the fields such as larger grasp force is needed to say, grabbed Dynamic stability, grasping precision and maximum grip power during holding tend not to meet these high-accuracy mission requirements；And Multi-finger clever hand class end effector, due to the complexity of its system, cost is often very high, and its freedom degree abundant and Flexibility does not need actually for much clamping tasks.

Utility model content

The purpose of the utility model is to provide a kind of variation rigidity complaisant grasping devices, by three-dimensional about X-axis, Y-axis, Z axis The method of symmetrical expression design flexible parallel mechanism, can not only guarantee the two-way parallel clamping operation on its open and close movement direction, Adapt to the clamping operation to different size objects；And can continuously change the clamping rigidity on its open and close movement direction, and It is constrained simultaneously by the design symmetry of self structure, eliminates its parasitic fortune not being expected on direction during stiffness equivalent Dynamic generation, to adapt to the clamping operation to different shape, different quality object.

Technical solution adopted by the utility model to solve the above technical problems is as follows: a kind of variation rigidity complaisant grasping device, Including two sliding blocks being slidably arranged in linear guide, sliding block by an open and close movement motor driven and can make it is relatively close and Far from movement.Each sliding block is connected with one for grabbing the clamping jaw of operation by variation rigidity flexible parallel mechanism, and variation rigidity is soft Property parallel institution is by a stiffness equivalent motor driven to adjust its rigidity.When working condition, by open and close movement motor driven, Control parallel clamping displacement of the clamping jaw on open and close movement direction；By stiffness equivalent motor driven, controls clamping jaw and transported in folding Clamping rigidity on dynamic.

Above-mentioned variation rigidity flexible parallel mechanism includes identical and parallel set on four between each sliding block and clamping jaw Compliant mechanism branch, each square configuration arranged of compliant mechanism branch, every two adjacent compliant mechanism branches Layout angle is symmetrical about the plane presentation mirror surface among it perpendicular to sliding block.This solves the base under different-stiffness state In the lateral buckling problem of single flexible mechanism branched configuration, it ensure that variation rigidity flexible parallel mechanism under any rigidity state Stability, while ensure that the working condition of parallel clamping operation in its clamping process.

Above-mentioned stiffness equivalent motor adjusts the distribution angle of each compliant mechanism branch by gear drive to adjust The rigidity state of whole variation rigidity flexible parallel mechanism.

Every above-mentioned compliant mechanism branch is connected by concatenated rubber universal joint, leaf spring flexible joint, intermediate rigidity respectively Bar, leaf spring flexible joint, rubber universal joint composition, gear drive adjust the distribution angle of leaf spring flexible joint.

Above-mentioned gear drive includes the pinion gear rotated coaxially with each compliant mechanism branch, and every two is adjacent The rotation direction of pinion gear is opposite.

One of pinion gear is the duplicate gear being made of two in-line gears on above-mentioned sliding block, duplicate gear and just Degree adjusts motor-driven worm gear and is fixedly and coaxially connected, and duplicate gear is engaged with neighbouring pinion gear respectively.Duplicate gear It is driven simultaneously with neighbouring pinion gear respectively again, so that the pinion gear on four transmission shafts of guarantee is at arranged position It is staggered up and down, to form an open loop transmission, so as to avoid interfering between stiffness equivalent operation transmission link middle gear Problem.

Above-mentioned stiffness equivalent motor passes through stiffness equivalent drive coordination belt wheel and stiffness equivalent drive coordination band driving one A splined shaft rotation, splined shaft are equipped with the left-hand worm and right-hand worm, left-hand worm and dextrorotation snail of the axially free sliding of energy Bar is rotated synchronously by spline and splined shaft.Left-handed worm wheel on left-hand worm and left slider.Right-hand worm and the right side Dextrorotation worm wheel on side slide.

Above-mentioned linear guide side is equipped with the dextrorotation lead screw and left-handed lead screw of the rotation of open and close movement motor driven, dextrorotation silk Thick stick and left-handed lead screw carry out threaded engagement with the nut on sliding block respectively.

Above-mentioned dextrorotation lead screw and left-handed lead screw are coaxially connected.Open and close movement motor passes through open and close movement drive coordination belt wheel Dextrorotation lead screw and the rotation of left-handed screw synchronous are driven with open and close movement drive coordination band.

When every compliant mechanism branch rotates 0 °, two clamping jaws in left and right are in minimum rigidity state, when every flexible machine When structure branch rotates 90 °, two clamping jaws in left and right are in maximum rigidity state.When clamping frangible, light-weight articles, preferably use it is small just Degree state is clamped, and when hard to be clamped, relatively large object, preferably use big rigidity state to be clamped.

Compared with existing identical variation rigidity principle art, the utility model passes through double parallel quadrangle flexible parallel mechanism Three dimensional symmetry formula configuration design, ensure that its clamping jaw being capable of parallel clamping operation during clamping movement；Pass through four phases The Constraints of Equilibrium of same and parallel compliant mechanism branch eliminates parasitic fortune on its direction that is not expected to during stiffness equivalent Dynamic generation solves the lateral buckling instability problem based on single flexible mechanism branch clamper；By will be single soft Property mechanism branch both ends be designed to symmetrical rubber universal joint, two transmission shafts are not coaxial during solving stiffness equivalent When the not smooth problem of transmission, improve the system performance of entire grabbing device.

Compared with existing other variation rigidity principle arts, the utility model has sufficiently large variation rigidity range, thus It can adapt to larger range of crawl mission requirements；The variation rigidity principle of the utility model belongs to mechanically structure control original Reason, so as to continuously and quickly change rigidity；The utility model adapts to difference by the open and close movement of macroscopic level Shangdi It is crawled the size of object, is operated by microcosmic degree Shangdi stiffness equivalent to adapt to the different shapes and matter for being crawled object Amount, and then it is adapted to different crawl tasks；Since its open and close movement and stiffness equivalent operation are independently controlled respectively, from And reduce the complexity of control system；Since its clamping jaw is directly embedded in the end of variation rigidity flexible parallel mechanism, thus So that the grabbing device has very high energy efficiency and rapidly can store and release energy.

Compared with traditional rigid crawl technology, the utility model realizes Cont rol Method of Precise Force by introducing stiffness equivalent operation Function is controlled, to need to can only carry out the crawl to different attribute object by a clamper, avoids conventional rigid clamping Device is time-consuming and heavy replaces the process of end grabbing device；And for the precision assembly process in factory, rigidity tune Whole operation increases flexibility and flexibility ratio in assembling process, to greatly increase the success rate of assembling link.

Detailed description of the invention

Fig. 1 is the two isogonism axonometric drawing of left and right of the utility model embodiment grabbing device.

Fig. 2 is the two isogonism axonometric drawing up and down of the utility model embodiment grabbing device.

Fig. 3 is stereoscopic schematic diagram of the grabbing device of the utility model embodiment under minimum rigidity state.

Fig. 4 is stereoscopic schematic diagram of the grabbing device of the utility model embodiment under intermediate rigidity state.

Fig. 5 is stereoscopic schematic diagram of the grabbing device of the utility model embodiment under maximum rigidity state.

Specific embodiment

Preferred embodiment below in conjunction with attached drawing 1 in 5 pairs of the utility model is described in further details, so as to more clearly Understand the purpose of this utility model, feature and advantage.It should be understood that embodiment shown in the drawings is not to the utility model The limitation of range, and simply to illustrate that the connotation of technical solutions of the utility model.

Fig. 1 to Fig. 5 is the schematic perspective view of variation rigidity complaisant grasping device in the present embodiment, appended drawing reference therein Are as follows: flange terminal pad 1, shell 2, dextrorotation worm gear 3, pinion gear 4, sliding block 5, linear guide 6, leaf spring flexible joint 7,8,9,10, Rubber universal joint 11,12,13,14, clamping jaw 15, dextrorotation lead screw 16, left-handed lead screw 17, left-handed worm gear 18, stiffness equivalent transmission it is same Walk band 19, open and close movement drive coordination band 20, stiffness equivalent motor 21, open and close movement motor 22, spline 23, left-hand worm 24, Right-hand worm 25, stiffness equivalent drive coordination belt wheel 26, open and close movement drive coordination belt wheel 27.

Variation rigidity complaisant grasping device in the utility model institute embodiment passes through the end of flange terminal pad 1 and robot Fixation is bolted between end, shell is fixedly connected between 2 inside by screw, wherein open and close movement motor 22 and rigidity Adjustment motor 21 is fixed on shell 2 by two supporting plates respectively, that is to say, that motor is relative to shell 2 during the motion Static, this also avoids in motion process wire intertwist into the generation of dangerous situation this in movement mechanism.

Open and close movement direction in the present embodiment refers to that clamping jaw 15 is transported during clamping object in the present invention Dynamic direction, this direction be it is two-way, not only can inwardly clamp but also can clamp outward.

It is fixed with open and close movement drive coordination belt wheel 27 on the main shaft of open and close movement motor 22, is driven by open and close movement same It walks band 20 to be driven, torque is driven to dextrorotation lead screw 16 and left-handed lead screw 17, dextrorotation lead screw 16 and left-handed lead screw 17 are in succession Connect the entirety being fixed together.The nut of dextrorotation lead screw 16 and dextrorotation sliding block 5 carries out threaded engagement, left-handed screw rod 17 and left-handed cunning The nut of block 5 carries out threaded engagement, makes two sliding blocks 5 carry out open and close movement along linear guide 6 by worm drive, in turn Clamping jaw 15 is driven to carry out open and close movement by variation rigidity flexible parallel mechanism.Variation rigidity flexible parallel mechanism is by stiffness equivalent motor 21 drivings are to adjust its rigidity.

Variation rigidity flexible parallel mechanism in the utility model is made of four identical and parallel compliant mechanism branches, Square configuration arranged in 5 plane of sliding block, upper and lower ends pass through bearing respectively and are connected to sliding block 5 and clamping jaw 15.Often Root compliant mechanism branch be respectively from top to bottom rubber universal joint 11,12,13,14, leaf spring flexible joint 7,8,9,10, it is intermediate just Property connecting rod, leaf spring flexible joint 7,8,9,10, rubber universal joint 11,12,13,14, and it is flat about the centre of intermediate rigid link Face is symmetrical at mirror surface.The effect of leaf spring flexible joint 7,8,9,10 is equivalent to the revolute pair in rigid joint, this four soft Property mechanism branch composition double parallel quadrilateral-shaped configuration parallel architecture, to ensure that two clamping jaws 15 in mutual open and close movement side To and off-axis movement direction on the depth of parallelism.

Stiffness equivalent motor 21 adjusts the distribution angle of each compliant mechanism branch by gear drive to adjust and become The rigidity state of rigidity flexible parallel mechanism.Gear drive includes the small tooth rotated coaxially with each compliant mechanism branch Wheel 4, the rotation direction of the adjacent pinion gear 4 of every two is opposite.Gear drive adjusts point of leaf spring flexible joint 7,8,9,10 Cloth angle.One of pinion gear 4 is the duplicate gear being made of two in-line gears, duplicate gear and rigidity on sliding block 5 The worm gear that adjustment motor 21 drives is fixedly and coaxially connected, and duplicate gear is engaged with neighbouring pinion gear 4 respectively.

Left-handed worm gear 18 and dextrorotation worm gear 3 are circumferentially fixed on active flexible mechanism branch by flat key in embodiment, And then it is fixed on sliding block 5 by bearing.When sliding block 5 along linear guide 6 carry out open and close movement and stiffness equivalent motor 21 does not have When having starting, due to the characteristic that the reverse self-locking of worm and gear is driven, left-handed worm gear 18 and dextrorotation worm gear 3 are left-handed from keyed respectively Worm screw 24 and right-hand worm 25, so that left-hand worm 24 and right-hand worm 25 be allowed to carry out sliding fortune along splined shaft by spline 23 Dynamic, it is decoupling that the drive motion that so links, which ensure that open and close movement is operated with stiffness equivalent, to reduce entire become just Spend the control complexity of complaisant grasping apparatus system.

Stiffness equivalent motor 21 in the present embodiment is equally driven by stiffness equivalent drive coordination band 19, and torque is passed It moves to left-hand worm 24 and right-hand worm 25, and then drives the rotation of active flexible mechanism branch by Worm Wheel System, into And by the duplicate gear on active flexible mechanism branch, successively pinion gear circumferentially fixed on neighbouring compliant mechanism branch 4 transmissions, the purpose of arrangement 4 positional configuration of pinion gear in this way is to guarantee that the drive motion between pinion gear 4 is open loop, thus ingenious Ground avoids and interferes with each other problem between closed loop gear drive, and due to the reason of gear clearance, closed loop gear drive is also possible to deposit Occur in locked situation.

The transmission of pinion gear 4 in the present embodiment belongs to external gear pump transmission, thus every two in its four pinion gears 4 The transmission direction of adjacent gear is opposite, thus ensure that the parallel branch of four compliant mechanisms during rotation, every two Adjacent compliant mechanism branch form is all about open and close movement direction and off-axis rigidity direction at axisymmetric, in any rigidity Symmetrical configuration under state eliminates the lateral buckling instability problem based on single flexible mechanism branched configuration clamper, Namely eliminate hunt effect based on single flexible mechanism configuration clamper on off-axis rigidity direction.Again because of its variation rigidity Principle is the structural form by controlling compliant mechanism itself, and then it is rigid on open and close movement direction to change compliant mechanism Degree, such mechanical variation rigidity principle implementation is easier to realize, and variation rigidity response speed is very fast.

The end positions of single flexible mechanism branch in the present embodiment be respectively rubber universal joint 11,12,13, 14, which is connect with sliding block 5 and clamping jaw 15 by bearing respectively, when clamping jaw 15 just touches object When body, two rubber universal joints, 11,12,13,14 axis of every compliant mechanism branch is parallel, however when sliding block 5 after When reforwarding is moved, the axis of the two rubber universal joints 11,12,13,14 is just deviateed at this time, and if wanting to pass through rotation at this time Compliant mechanism branch changes clamping jaw 15 in the rigidity on open and close movement direction, the configuration arrangement of this double Hooke's joint transmission, Just dexterously solve the problems, such as that transmission of two transmission shafts when not coaxial be not smooth, to ensure that variation rigidity flexible parallel connection machine The stability configuration of structure, and then improve the stability and fluency of entire variation rigidity complaisant grasping apparatus system.

When every compliant mechanism branch rotates 0 °, two clamping jaws 15 in left and right are in minimum rigidity state, when every flexibility When mechanism branch rotates 90 °, two clamping jaws 15 in left and right are in maximum rigidity state.Minimum rigidity state, intermediate rigidity state, most " rigidity state " in big rigidity state, all refers to that clamping jaw 15 is rigid on open and close movement direction in variation rigidity complaisant grasping device Spend size.

Variation rigidity complaisant grasping device in the present embodiment preferably selects figure when grabbing the object of frangible, lighter attribute The rigidity state between intermediate rigidity state in minimum rigidity state in 3 and Fig. 4 is grabbed.And when crawl hard, compared with When the object of weight attribute, preferably select rigidity state between the highest rigidity state in the intermediate rigidity state in Fig. 4 and Fig. 5 into Row crawl.

For crawl strategy, can first pass through control open and close movement motor 22 makes clamping jaw 15 translate a certain distance, Then rigidity state of the clamping jaw 15 on open and close movement direction is changed by control stiffness equivalent motor 21 again, such operation is real It is equivalent to first apply a smaller power on being crawled object on border, then slowly be reinforced on being crawled object again, directly It is crawled until object is enough to be clamped by clamping jaw 15 to this.It can also be rigid by control first according to the requirement of clamping task Degree adjustment motor 21, selects suitable rigidity state for clamping jaw 15 on open and close movement direction, then passes through control folding fortune again Dynamic motor 22, makes clamping jaw 15 translate enough distances, is crawled until object is enough to be clamped by clamping jaw 15 until this, this behaviour Making practical first-class effect is uniformly to be reinforced on being crawled object with faster speed.For practical operation operation, work as needs When Cont rol Method of Precise Force control is assembled, it should select the first clamping strategy to carry out assembly manipulation, with improve the flexibility of assembling link with Flexibility ratio.When we need to pick when being crawled object of different attribute, it should second of clamping strategy be selected to be grabbed Operation, it is therefore an objective to it is crawled the attribute of object according to difference, selects suitable rigidity state to improve the adaptability of clamping jaw 15, To improve the success rate of grasping, and certain operation activity duration is saved, and then improves the efficiency of operation operation.

The technical solution of the utility model is described in detail in embodiment described above, it is understood that more than Described is only specific embodiment of the utility model, is not intended to limit the utility model, all principle models in the utility model Interior done any modification, supplement or similar fashion substitution etc. are enclosed, such equivalent forms equally fall within right appended by the application and want It asks within book limited range.

Claims (10)

1. a kind of variation rigidity complaisant grasping device, it is characterised in that: including two sliding blocks being slidably arranged on linear guide (6) (5), the sliding block (5) is driven by an open and close movement motor (22) and can make relatively close and separate movement；It is each described Sliding block (5) be connected with one for grabbing the clamping jaw (15) of operation, the variation rigidity by variation rigidity flexible parallel mechanism Flexible parallel mechanism is by stiffness equivalent motor (21) driving to adjust its rigidity.

2. variation rigidity complaisant grasping device according to claim 1, it is characterised in that: the variation rigidity flexible parallel connection machine Structure includes set on four identical and parallel compliant mechanism branches between each sliding block (5) and clamping jaw (15), each flexible machine The square configuration arranged of structure branch, the layout angles of every two adjacent compliant mechanism branches about among it perpendicular to It is symmetrical that mirror surface is presented in the plane of sliding block (5).

3. variation rigidity complaisant grasping device according to claim 2, it is characterised in that: the stiffness equivalent motor (21) The distribution angle of each compliant mechanism branch is adjusted by gear drive to adjust the rigidity of variation rigidity flexible parallel mechanism State.

4. variation rigidity complaisant grasping device according to claim 3, it is characterised in that: compliant mechanism branch described in every It is made of respectively concatenated rubber universal joint, leaf spring flexible joint, intermediate rigid link, leaf spring flexible joint, rubber universal joint, The distribution angle of the gear drive adjustment leaf spring flexible joint.

5. variation rigidity complaisant grasping device according to claim 4, it is characterised in that: the gear drive includes The pinion gear (4) rotated coaxially with each compliant mechanism branch, the rotation direction of the adjacent pinion gear of every two (4) are opposite.

6. variation rigidity complaisant grasping device according to claim 5, it is characterised in that: therein one on the sliding block (5) A pinion gear (4) is the duplicate gear being made of two in-line gears, and the duplicate gear and stiffness equivalent motor (21) are driven Dynamic worm gear is fixedly and coaxially connected, and duplicate gear is engaged with neighbouring pinion gear (4) respectively.

7. variation rigidity complaisant grasping device according to claim 6, it is characterised in that: the stiffness equivalent motor (21) A splined shaft rotation is driven by stiffness equivalent drive coordination belt wheel (26) and stiffness equivalent drive coordination band (19), it is described Splined shaft is equipped with left-hand worm (24) and right-hand worm (25), the left-hand worm (24) and the right side of the axially free sliding of energy Worm screw (25) are revolved to rotate synchronously by spline (23) and splined shaft；A left side on the left-hand worm (24) and left slider (5) Rotation worm gear (18) matches；The right-hand worm (25) is matched with the dextrorotation worm gear (3) on right side sliding block (5).

8. variation rigidity complaisant grasping device according to claim 1, it is characterised in that: described linear guide (6) side Equipped with open and close movement motor (22) driving rotation dextrorotation lead screw (16) and left-handed lead screw (17), the dextrorotation lead screw (16) and Left-handed lead screw (17) carries out threaded engagement with the nut on sliding block (5) respectively.

9. variation rigidity complaisant grasping device according to claim 8, it is characterised in that: the dextrorotation lead screw (16) and a left side It is coaxially connected to revolve lead screw (17)；The open and close movement motor (22) passes through open and close movement drive coordination belt wheel (27) and folding fortune Dynamic drive coordination band (20) driving the dextrorotation lead screw (16) and left-handed lead screw (17) rotate synchronously.

10. according to variation rigidity complaisant grasping device described in claim 2 to 7 any claim, it is characterised in that: when every When compliant mechanism branch rotates 0 °, two clamping jaws (15) in left and right are in minimum rigidity state, when every compliant mechanism branch rotates At 90 °, two clamping jaws (15) in left and right are in maximum rigidity state.