CN115523257A - Six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles - Google Patents
Six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles Download PDFInfo
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- CN115523257A CN115523257A CN202210989928.1A CN202210989928A CN115523257A CN 115523257 A CN115523257 A CN 115523257A CN 202210989928 A CN202210989928 A CN 202210989928A CN 115523257 A CN115523257 A CN 115523257A
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- 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
- F16F15/04—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 elastic means
- F16F15/06—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 elastic means with metal springs
- F16F15/073—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 elastic means with metal springs using only leaf springs
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Abstract
The invention discloses a six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles, which comprises an upper platform, an upper mounting angle seat, an adjustable dynamic variable stiffness mechanism, a lower mounting angle seat and a lower platform, wherein the upper end of the adjustable dynamic variable stiffness mechanism is connected with the upper platform through the upper mounting angle seat, the lower end of the adjustable dynamic variable stiffness mechanism is connected with the lower platform through the lower mounting angle seat, the device is based on a multi-degree-of-freedom parallel configuration and consists of six identical adjustable dynamic variable stiffness mechanisms, and the adjustable dynamic variable stiffness mechanism can be adjusted into two states of adjustable dynamic low stiffness and adjustable dynamic high stiffness, so that the adjustable dynamic variable stiffness mechanism is formed.
Description
Technical Field
The invention relates to the technical field of variable stiffness, in particular to a six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles.
Background
With the development of scientific technology and the emergence of emerging subjects, the fields of industrial production, medical instruments, space exploration and the like all put higher demands on the variable stiffness field, for example, the variable stiffness device has gradually become a popular research field in the robot research field, and because the variable stiffness device can change the stiffness of the variable stiffness device according to different requirements, the safety of human-computer interaction can be improved, and particularly in the occasions closely contacted with people, such as the service industry, the medical industry and the like, more and more people begin to research the variable stiffness device due to the wide prospect. Therefore, the rigidity-changing device with stronger function and better adaptability plays an irreplaceable role. The device with the adjustable dynamic stiffness changing function can realize the functions of supporting, limiting, protecting and the like on an object in a high-stiffness state, and can also realize the vibration damping function on the object in a low-stiffness state.
The adjustable rigidity mechanism has two forms of passive adjustment and active adjustment at present, and in the aspect of active rigidity change, the rigidity adjustable switch is controlled by generally adopting a mode of adding extra drive to realize real-time adjustment of rigidity. The passive variable stiffness mainly adopts the modes of magnetic attraction, manual adjustment and the like, and has the defect that the stiffness of the device cannot be regulated and controlled in real time, but the structural size of the common variable stiffness device is larger, the external energy required by active adjustment is larger, and in addition, the control device is more complex, so the application degree of the device is not as wide as that of passive adjustment.
The patent specification with publication number CN109968397B discloses a self-adaptive passive variable stiffness joint, which is mainly used for solving the problems of large joint size, slow response and the like of the existing variable stiffness joint.
Disclosure of Invention
The invention aims to provide a six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles, which aims to solve the problems in the prior art, the variable stiffness device is based on a multi-degree-of-freedom parallel configuration, utilizes the stiffness superposition principle of a positive stiffness plate spring and a V-shaped plate spring, realizes the conversion of the positive stiffness and the negative stiffness of the V-shaped plate spring by controlling a stiffness switch, further changes the stiffness of a system, ensures that the system forms two stiffness structural forms, and realizes an adjustable dynamic high stiffness structural form when the stiffness switch is closed, so that the structure can realize the functions of supporting, limiting, protecting and the like on an object; when the rigidity switch is turned on, the system realizes an adjustable dynamic low-rigidity structure form, and the structure can realize the vibration reduction effect on an object.
In order to achieve the purpose, the invention provides the following scheme: the invention provides a six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles, which comprises
The upper platform is used for contacting with a load, three first grooves and three second grooves are formed in the bottom surface of the upper platform, and the circumference where the three first grooves on the inner side are located and the circumference where the three second grooves on the outer side are located are concentric circles; and
the mounting angle seat comprises an upper mounting angle seat and a lower mounting angle seat which have the same structure, each first groove and each second groove are respectively connected with the upper mounting angle seat through countersunk bolts, and the bottom of the upper mounting angle seat is connected with a bearing column of the adjustable dynamic variable stiffness mechanism; and
the adjustable dynamic variable stiffness mechanism comprises a bearing column, an upper cover, a positive stiffness plate spring, an auxiliary mounting block, a first supporting beam mounting plate, a second supporting beam mounting plate, a connecting rod, a stiffness switch, a V-shaped plate spring, a cylindrical shell and a lower cover, wherein the upper cover and the lower cover are respectively mounted at two ends of the cylindrical shell, and the bearing column penetrates through the upper cover and then is arranged in an inner cavity of the cylindrical shell; the bearing column positioned in the inner cavity of the cylindrical shell is sequentially connected with the positive-stiffness plate spring, the V-shaped plate spring and the positive-stiffness plate spring, and the other end of the positive-stiffness plate spring is connected with the cylindrical shell through an auxiliary mounting block; the other end of the V-shaped plate spring is fixedly connected with the connecting rod; the lower end of the connecting rod is connected with the rigidity switch, the two sides of the connecting rod are respectively provided with the second supporting beam mounting plate, the two ends of the supporting beam are respectively welded with the first supporting beam mounting plate and the second supporting beam mounting plate, and the lower end of the first supporting beam mounting plate is fixedly connected with the cylindrical shell through a bolt; and
the lower platform is used for contacting with a foundation, three third grooves and three fourth grooves are formed in the top surface of the lower platform, the number of the inner sides of the three grooves is the same as that of the outer sides of the three grooves, the number of the inner sides of the three grooves is the same as that of the outer sides of the four grooves, and the third grooves and the fourth grooves are connected with the lower mounting angle seat through countersunk bolts.
In one embodiment, the centers of the upper platform and the lower platform are on a vertical line, the diameter of the circumference where the first groove is located is the same as that of the circumference where the third groove is located, and the diameter of the circumference where the second groove is located is the same as that of the circumference where the fourth groove is located.
In one embodiment, the main body of the upper platform comprises a central platform, connecting plates and a hexagonal platform, the central platform and the hexagonal platform are concentrically arranged, a plurality of connecting plates are uniformly distributed and connected in the circumferential direction of the central platform, and the other ends of the connecting plates are fixedly connected with the inner sides of the hexagonal platform; the outer side edge line of the hexagonal platform is hexagonal, and the inner side edge is circular.
In one embodiment, the main body of the lower platform comprises a central platform, a connecting plate and a hexagonal platform, the central platform and the hexagonal star platform are concentrically arranged, a plurality of connecting plates are uniformly distributed and connected in the circumferential direction of the central platform, and the other ends of the connecting plates are fixedly connected with the inner side of the hexagonal star platform; the outer side edge line of the hexagonal star platform is a regular hexagonal star shape, and the inner side edge of the hexagonal star platform is circular.
In one embodiment, the upper mounting angle seat comprises a cylinder and a chamfer positioned on one side of the top of the cylinder, and threaded holes are formed in the cylinder and the chamfer.
In one embodiment, each of the first groove and the second groove is respectively connected with the cylinder of the upper mounting angle base through a countersunk bolt, and the chamfered surface of the upper mounting angle base is connected with the bearing column of the adjustable dynamic stiffness changing mechanism through a stud; each third groove and fourth groove all through countersunk head bolt with the cylinder of lower installation angle seat is connected, the scarf of lower installation angle seat pass through stud with adjustable dynamic variable rigidity mechanism's lower cover links to each other.
In one embodiment, the upper end of the upper cover is provided with a through hole with the diameter larger than that of the bearing column; and four threaded holes are formed in the circumference of the lower end of the upper cover and are respectively connected with the cylindrical shell through screws.
In one embodiment, two ends of the positive stiffness plate spring are welded with auxiliary mounting blocks, and the auxiliary mounting blocks at the two ends of the positive stiffness plate spring are provided with through holes respectively used for being connected with the bearing column and the cylindrical shell; the upper end of the V-shaped plate spring is welded with the auxiliary mounting block, the auxiliary mounting block at the upper end of the V-shaped plate spring is connected with the bearing column through a screw, and the lower end of the V-shaped plate spring is fixedly connected with the connecting rod through a bolt.
In one embodiment, when the stiffness switch is turned off, the V-shaped leaf spring is in a linear state, and provides positive stiffness to the adjustable dynamic stiffness changing mechanism, and the stiffness analytic formula of the V-shaped leaf spring is as follows:
the V-shaped plate spring and the positive-stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic high-stiffness structural form;
when the rigidity switch is opened, the V-shaped plate spring is in a bending state, the V-shaped plate spring provides negative rigidity in the axial direction of the bearing column for the adjustable dynamic rigidity changing mechanism, and the rigidity analytic expression is as follows:
the V-shaped plate spring and the positive-stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic low-stiffness structural form.
In one embodiment, the adjustable dynamic stiffness changing mechanism comprises a first adjustable dynamic stiffness changing mechanism, a second adjustable dynamic stiffness changing mechanism, a third adjustable dynamic stiffness changing mechanism, a fourth adjustable dynamic stiffness changing mechanism, a fifth adjustable dynamic stiffness changing mechanism and a sixth adjustable dynamic stiffness changing mechanism, and any two adjustable dynamic stiffness changing mechanisms are parallel or vertical to each other in space; the first groove comprises a first groove, a second groove and a third groove, the second groove comprises a first groove, a second groove and a third groove, the third groove comprises a first groove, a second groove and a third groove, the fourth groove comprises a first groove, a second groove and a third groove, the upper end and the lower end of the first adjustable dynamic stiffness changing mechanism are assembled in the first groove and the first groove through the upper mounting angle seat and the lower mounting angle seat respectively, the upper end and the lower end of the second adjustable dynamic stiffness changing mechanism are assembled in the first groove and the second groove through the upper mounting angle seat and the lower mounting angle seat respectively, the upper end and the lower end of the third adjustable dynamic stiffness changing mechanism are assembled in the second groove and the third groove respectively through the upper mounting angle seat and the lower mounting angle seat respectively, the upper end and the lower end of the fourth adjustable dynamic stiffness changing mechanism are assembled in the second groove and the fourth groove respectively through the upper mounting angle seat and the lower mounting angle seat respectively, the upper end and the lower end of the fourth adjustable dynamic stiffness changing mechanism are assembled in the second groove and the third groove through the upper mounting angle seat and the lower mounting angle seat respectively, and the upper end and the lower mounting angle seat of the adjustable dynamic stiffness changing mechanism are assembled in the second groove and the third groove respectively, and the upper mounting angle seat respectively.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention relates to a six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles, which comprises an upper platform, an upper mounting angle seat, an adjustable dynamic variable stiffness mechanism, a lower mounting angle seat and a lower platform, wherein the upper end of the adjustable dynamic variable stiffness mechanism is connected with the upper platform through the upper mounting angle seat, the lower end of the adjustable dynamic variable stiffness mechanism is connected with the lower platform through the lower mounting angle seat, the device is based on a multi-freedom-degree parallel configuration and comprises six same adjustable dynamic variable stiffness mechanisms, and the adjustable dynamic variable stiffness mechanism can be adjusted into two states of adjustable dynamic low stiffness and adjustable dynamic high stiffness, so that the adjustable dynamic variable stiffness mechanism is formed.
The variable stiffness device is an adjustable dynamic variable stiffness device based on a multi-degree-of-freedom parallel configuration, and has two adjustable dynamic stiffness structural forms, wherein an adjustable dynamic high stiffness structure is mainly applied to the functions of supporting, limiting, protecting and the like of an object, and an adjustable dynamic low stiffness structure is mainly applied to the inhibition of the influence of external disturbance on the normal work of equipment.
The adjustable dynamic variable stiffness mechanism adopts a concentric circle mounting structure, so that the adjustable dynamic variable stiffness mechanisms can be symmetrically mounted in pairs, and uniform loading of each adjustable dynamic variable stiffness mechanism is ensured when the device is loaded. The positive stiffness plate spring and the V-shaped plate spring in the adjustable dynamic stiffness changing mechanism meet the stiffness superposition principle, and the plate spring can be used as a vibration damping device to damp vibration transfer energy while meeting the system stiffness.
The positive-rigidity plate spring, the V-shaped plate spring and the supporting beam are connected with the bearing column and the cylindrical shell through the auxiliary mounting block through bolts, so that the positive-rigidity plate spring, the V-shaped plate spring and the supporting beam are convenient to replace, the rigidity of the element can be adjusted by changing the size, the material and the like of the element, the rigidity of a system is changed, and the function of adjusting and changing the rigidity is realized.
In the adjustable dynamic variable stiffness structure, the first stiffness structure is an adjustable dynamic high stiffness structure, when the stiffness switch is closed, the V-shaped plate spring is not loaded and provides positive stiffness, the positive stiffness plate spring provides support, the V-shaped plate spring and the positive stiffness plate spring meet the stiffness superposition principle, and the positive stiffness provided by the V-shaped plate spring is superposed with the positive stiffness provided by the positive stiffness plate spring, so that the high stiffness state of the whole device is realized, and the state can realize the functions of supporting, limiting, protecting and the like on an object.
In the adjustable dynamic variable stiffness structure, the second stiffness structure is an adjustable dynamic low stiffness structure, when the stiffness switch is opened, the V-shaped plate spring is loaded and bent to provide negative stiffness, the positive stiffness plate spring provides support, the V-shaped plate spring and the positive stiffness plate spring meet the stiffness superposition principle, the negative stiffness provided by the V-shaped plate spring is superposed with the positive stiffness provided by the positive stiffness plate spring, so that the stiffness of the mechanism is reduced, a quasi-zero stiffness state can be achieved, and the state mainly realizes the vibration damping effect on an object.
The connecting parts of the variable-rigidity device are fixedly connected by bolts and screws, so that the reliability of the whole device is ensured.
The adjustable dynamic variable stiffness device has the advantages of simple structure, stable work, lower manufacturing and maintenance cost and convenient structure replacement, and can effectively realize the functions of fixing support, limiting, protecting, inhibiting natural frequency and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 (a) is a schematic diagram of the structure of the upper platen according to the present invention;
FIG. 2 (b) is a schematic view of the structure of the lower stage of the present invention;
FIG. 3 (a) is a schematic view of a mounting bracket according to the present invention;
FIG. 3 (b) is a cross-sectional view of the mounting bracket of the present invention;
FIG. 4 (a) is a schematic view of an adjustable dynamic stiffness-varying mechanism according to the present invention;
FIG. 4 (b) is a cross-sectional view of the adjustable dynamic stiffness mechanism of the present invention;
FIG. 5 (a) is a schematic diagram of the stiffness switch of the present invention in an off state;
FIG. 5 (b) is a schematic diagram of the open state of the stiffness switch of the present invention;
FIG. 6 (a) is a schematic diagram of the state of the V-shaped leaf spring in the case of the adjustable dynamic high stiffness structure of the present invention;
FIG. 6 (b) is a schematic diagram of the state of the V-shaped leaf spring in the case of the adjustable dynamic low stiffness structure of the present invention;
FIG. 7 is a graph comparing the V-shaped spring force versus displacement curves for two stiffness conditions in the present invention;
wherein the reference numerals are: 1-an upper platform; 2-mounting an angle seat; 3-a stud; 4-adjustable dynamic variable stiffness mechanism; 41-adjustable dynamic variable stiffness mechanism I; 42-an adjustable dynamic variable stiffness mechanism II; 43-adjustable dynamic variable stiffness mechanism III; 44-adjustable dynamic stiffness changing mechanism four; 45-an adjustable dynamic variable stiffness mechanism V; 46-adjustable dynamic variable stiffness mechanism six; 5-lower mounting angle seats; 6-lower platform; 7-a support column; 8-upper cover; 9-positive stiffness leaf springs; 10-an auxiliary mounting block; 11-a support beam mounting plate I; 12-a support beam; 13-a second supporting beam mounting plate and 14 connecting rods; 15-a stiffness switch; a 16-V shaped leaf spring; 17-a cylindrical housing; 18-lower cover.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles, which aims to solve the problems in the prior art, the variable stiffness device is based on a multi-degree-of-freedom parallel configuration, utilizes the stiffness superposition principle of a positive stiffness plate spring and a V-shaped plate spring, realizes the conversion of the positive stiffness and the negative stiffness of the V-shaped plate spring by controlling a stiffness switch, further changes the stiffness of a system, ensures that the system forms two stiffness structural forms, and realizes an adjustable dynamic high stiffness structural form when the stiffness switch is closed, so that the structure can realize the functions of supporting, limiting, protecting and the like on an object; when the rigidity switch is turned on, the system realizes an adjustable dynamic low-rigidity structure form, and the structure can realize the vibration damping effect on an object.
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description thereof.
As shown in fig. 1 to 7, the invention provides a six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles, which comprises an upper platform 1, an upper mounting angle seat 2, a stud 3, an adjustable dynamic variable stiffness mechanism 4, a lower mounting angle seat 5 and a lower platform 6. The whole structure is compact, the occupied space is small, the equipment manufacturing and maintenance cost is low, the parts are convenient to replace, and the parts can be replaced according to actual application occasions to change the system rigidity of the device. The adjustable dynamic variable stiffness device has two stiffness structural forms, namely an adjustable dynamic high stiffness structural form and an adjustable dynamic low stiffness structural form, and the two stiffness structural forms are switched by controlling the stiffness switch.
FIG. 2 (a) is a schematic structural diagram of an upper platform of the invention, the upper platform 1 is a scalene hexagonal prism and is used for contacting with a load, six grooves are formed on the bottom surface of the upper platform 1, the circumference of three grooves close to the center and the circumference of three grooves close to the outer side are concentric circles, and threaded holes formed in the middle of the six grooves are connected with an upper mounting angle base 2 through countersunk bolts; the lower platform 6 is in a hexagon-star-like shape, six grooves are formed in the plane of the lower platform 6 and the upper platform 1, the circumferences of the grooves are concentric circles, a threaded through hole is formed in the middle of each groove of the upper platform and the lower platform, the adjustable dynamic variable stiffness mechanisms 4 are fixedly connected with the upper platform 1 and the lower platform 6 through mounting angle seats respectively, the adjustable dynamic variable stiffness mechanisms 4 are symmetrical in pairs by adopting a concentric circle mounting structure, and the uniform loading of each adjustable dynamic variable stiffness mechanism is guaranteed when the device is loaded.
Fig. 3 (a) - (b) are schematic views and sectional views of the mounting angle seat of the present invention. The mounting angle seat is provided with a chamfer plane, so that the force transmission direction in the adjustable dynamic stiffness changing mechanism 4 is not along a vertical line, the natural decoupling of a space cube can be realized, the chamfer plane and the upper end surface of the mounting angle seat are respectively provided with a threaded hole, the chamfer plane of the upper mounting angle seat 2 is connected with a bearing column 7 in the adjustable dynamic stiffness changing mechanism 4 through a stud 3, the upper end surface is connected with the upper platform 1 through a countersunk head bolt, the chamfer plane of the lower mounting angle seat 5 is connected with the lower cover 18 through the stud 3, and the upper end surface is connected with the lower platform 6 through the countersunk head bolt. The upper and lower mounting angle seats can be used interchangeably.
The number of the adjustable dynamic stiffness changing mechanisms 4 is six, and the adjustable dynamic stiffness changing mechanisms are respectively an adjustable dynamic stiffness changing mechanism I41, an adjustable dynamic stiffness changing mechanism II 42, an adjustable dynamic stiffness changing mechanism III 43, an adjustable dynamic stiffness changing mechanism IV 44, an adjustable dynamic stiffness changing mechanism V45 and an adjustable dynamic stiffness changing mechanism VI 46, the first groove comprises a first groove I, a second groove II and a first groove III, the second groove comprises a second groove I, a second groove II and a second groove III, the third groove comprises a third groove I, a third groove II and a third groove III, the fourth groove comprises a fourth groove I, a fourth groove II and a third groove III, the upper end and the lower end of the adjustable dynamic stiffness changing mechanism I41 are respectively assembled in the first groove I and the fourth groove I through an upper mounting angle seat 2 and a lower mounting angle seat 5, the upper end and the lower end of a second adjustable dynamic stiffness changing mechanism 42 are respectively assembled in a first second groove and a first third groove through an upper mounting angle seat 2 and a lower mounting angle seat 5, the upper end and the lower end of a third adjustable dynamic stiffness changing mechanism 43 are respectively assembled in a second first groove and a second fourth groove through the upper mounting angle seat 2 and the lower mounting angle seat 5, the upper end and the lower end of a fourth adjustable dynamic stiffness changing mechanism 44 are respectively assembled in the second groove and the second third groove through the upper mounting angle seat 2 and the lower mounting angle seat 5, the upper end and the lower end of a fifth adjustable dynamic stiffness changing mechanism 45 are respectively assembled in the third first groove and the third groove through the upper mounting angle seat 2 and the lower mounting angle seat 5, and the upper end and the lower end of a sixth adjustable dynamic stiffness changing mechanism 46 are respectively assembled in the third groove and the third groove through the upper mounting angle seat 2 and the lower mounting angle seat 5. Six adjustable dynamic variable stiffness mechanisms 4 are fixedly connected with the upper and lower mounting angle seats through double-end studs 3, and each adjustable dynamic variable stiffness mechanism 4 is parallel or vertical to each other in space.
Fig. 4 (a) - (b) are schematic diagrams and sectional views of the adjustable dynamic stiffness changing mechanism in the invention. The adjustable dynamic variable stiffness mechanism 4 comprises a bearing column 7, an upper cover 8, a positive stiffness plate spring 9, an auxiliary mounting block 10, a first supporting beam mounting plate 11, a supporting beam 12, a second supporting beam mounting plate 13, a connecting rod 14, a stiffness switch 15, a V-shaped plate spring 16, a cylindrical shell 17 and a lower cover 18. The bearing column 7 is in a cylindrical shape, the outer side of the cylinder is provided with a threaded hole, the bearing column is fixedly connected with the V-shaped plate spring 16 and the positive stiffness plate spring 9 through bolts, the upper end of the bearing column 7 is provided with a threaded hole, and the bearing column is fixedly connected with the upper mounting angle seat 2 through the stud 3.
Two ends of the positive-rigidity plate spring 9 are welded with auxiliary mounting blocks 10, and the auxiliary mounting blocks 10 are provided with through holes respectively used for being connected with the bearing column 7 and the cylindrical shell 17. The upper end of the V-shaped plate spring 16 is welded with the auxiliary mounting block 10, the auxiliary mounting block 10 is provided with a through hole and is connected with the bearing column 7 through a screw, the lower end of the V-shaped plate spring 16 is provided with a through hole, and the V-shaped plate spring 16 is fixedly connected with the connecting rod 14 through a bolt. The positive stiffness plate spring 9 and the V-shaped plate spring 16 are convenient to detach and easy to replace, and the adjustable stiffness of the device can be easily realized by replacing the positive stiffness plate spring 9 and the V-shaped plate spring 16. The upper side and the lower side of the cylindrical shell 17 are respectively provided with 4 threaded holes which are respectively used for being fixedly connected with the upper cover 8 and the lower cover 18 through screws, and the outer side of the cylindrical shell 17 is provided with a plurality of through holes which are respectively used for being fixedly connected with the positive-rigidity plate spring 9 and the supporting beam mounting plate I11 through screws and mounting the rigidity switch 15. The upper end of the upper cover 8 is provided with a through hole with a diameter larger than that of the bearing column 7 for installing the bearing column 7 and limiting the bearing column, and the circumference of the lower end is provided with 4 threaded holes which are connected with the cylindrical shell 17 through screws.
Fig. 5 (a) - (b) are schematic diagrams of the closed state and the open state of the rigid switch 15 in the present invention. The rigidity switch 15 is used for controlling the rigidity structure form of the device, when the rigidity switch 15 is closed, the device is in the adjustable dynamic high rigidity structure form, and when the rigidity switch 15 is opened, the device is in the adjustable dynamic low rigidity structure form. Two steel plates extending out of the upper side of the rigidity switch 15 are provided with two threaded holes and are connected with the connecting rod 14 through bolts. The connecting rod 14 is provided with 4 threaded holes, the two lower sides of the connecting rod are connected with the rigidity switch 15, and the two upper sides of the connecting rod are connected with the second supporting beam mounting plate 13. Two sides of the supporting beam 12 are respectively welded with the first supporting beam mounting plate 11 and the second supporting beam mounting plate 13, the lower end of the first supporting beam mounting plate 11 is welded with the auxiliary mounting block 10 and is fixedly connected with the cylindrical shell 17 through bolts, and threaded holes are formed in the upper side and the lower side of the second supporting beam mounting plate 13 and are fixedly connected with the connecting rod 14 through bolts. The supporting beam 12 is used for preventing the rigidity switch 15 from being automatically closed after the bearing column 7 is loaded after the rigidity switch 15 is opened, thereby playing a self-locking role. The supporting beam 12, the supporting beam mounting plate I11 and the supporting beam mounting plate II 13 form a supporting beam structure module, and the supporting beam structure module can be replaced, so that the self-locking condition of the rigidity switch of the adjustable dynamic rigidity changing mechanism under different rigidities is realized.
Specifically, the total number of the positive-stiffness plate springs 9 is 6, the positive-stiffness plate springs are mainly used for providing positive stiffness for the adjustable dynamic variable-stiffness mechanism 4, every two positive-stiffness plate springs 9 form a group, each group forms a 120-degree angle and is uniformly distributed on the outer side of the bearing column 7, two sides of each positive-stiffness plate spring 9 are respectively welded with the auxiliary mounting blocks 10, the auxiliary mounting blocks 10 are provided with threaded holes, the auxiliary mounting blocks 10 on one side are fixedly connected with the bearing column 7 through bolts, and the auxiliary mounting blocks 10 on the other side are fixedly connected with the cylindrical shell 17 through bolts. Therefore, the positive stiffness plate spring 9 is convenient to replace, and the adjustable stiffness of the adjustable dynamic stiffness changing mechanism 4 is achieved.
The number of the V-shaped plate springs 16 is 6, and the V-shaped plate springs have two forms, one form is that when the rigidity switch 15 is closed, the rigidity switch is in a linear shape, positive rigidity is provided, and the adjustable dynamic rigidity changing mechanism 4 is in a high-rigidity structural form and can support, limit and protect objects; the other is that when the rigidity switch 15 is opened, the rigidity switch is bent, negative rigidity is provided, and the adjustable dynamic rigidity changing mechanism 4 is in a low rigidity structure form and can play a role in damping vibration of an object; every two V-shaped plate springs 16 form a group, an angle of 45 degrees is formed between every two V-shaped plate springs 16 in each group, an angle of 120 degrees is formed between every two groups and is uniformly distributed on the outer side of the bearing column 7, the upper sides of the V-shaped plate springs 16 are welded with the auxiliary mounting block 10, the auxiliary mounting block 10 is provided with a threaded hole, and the V-shaped plate springs and the bearing column 7 are fixedly connected through bolts; the lower side of the V-shaped plate spring 16 is provided with a threaded hole and is connected with the connecting rod 14 through a bolt. The V-shaped plate spring 16 can be replaced, so that the rigidity of the adjustable dynamic rigidity changing mechanism can be adjusted.
3 connecting rods 14 are provided, four through holes are formed in each connecting rod 14, and the first through hole on the upper side connects the two side supporting beam mounting plates 13 and the two side V-shaped plate springs 16 together through bolts; the second through hole is connected with the two side supporting beam mounting plates 13 through bolts; the two through holes at the lower side are fixedly connected with the rigidity switch 15 through bolts.
18 supporting beams 12 are total, each supporting beam 12 is in a form that two sides are thin and the middle is thick, the tensile strength is improved, 3 supporting beams are in a group, two sides of each group of supporting beams are respectively welded with a first supporting beam mounting plate 11 and a second supporting beam mounting plate 13, through holes are formed in the upper side and the lower side of the second supporting beam mounting plate 13 and are connected with a connecting rod 14 through bolts, an auxiliary mounting block 10 is welded on the lower side of the first supporting beam mounting plate 11, a through hole is formed in the auxiliary mounting block 10, and the auxiliary mounting block is connected with a cylindrical shell 17 through bolts. The supporting beam 12 has the function of preventing the load-bearing column 7 from being automatically closed after the rigidity switch 15 is opened, thereby having the self-locking function. The supporting beam structure can be replaced, so that the self-locking condition of the adjustable dynamic variable stiffness mechanism 4 under different stiffness conditions is realized.
The number of the rigidity switches 15 is 3, and the rigidity switches are mainly used for controlling the rigidity state of the damping mechanism, so that different functions are controlled and realized; the upper side of the rigidity switch 15 is provided with 4 through holes which are respectively fixedly connected with the connecting rod 14 through bolts.
The lower cover 18 and the upper cover 8 are mainly used for being connected with the cylindrical shell 17, 4 threaded holes are formed in the peripheries of the upper cover 8 and the lower cover 18 and used for being connected with the cylindrical shell 17, a threaded hole is formed in the bottom side of the lower cover 18 and used for being connected with the lower mounting angle seat 5 through a stud, and a circular through hole is formed in the upper end of the upper cover 8 and used for limiting the bearing column 7. The cylinder outside of cylinder shell 17 is opened 24 circular through-holes altogether for be connected through the bolt with positive rigidity leaf spring 9 and a supporting beam mounting panel 11, and 3 square through-holes have still been opened in the cylinder outside, are used for bistable switch installation, and 4 screw holes have all been opened at cylinder shell 17 upper and lower both ends, carry out fixed connection with upper cover 8 and lower cover 18 respectively.
Fig. 6 (a) - (b) are schematic diagrams of the states of the V-shaped leaf spring in the case of the adjustable dynamic high stiffness structure and the adjustable dynamic low stiffness structure of the present invention. The upper end of the V-shaped plate spring is welded with the auxiliary mounting block, the auxiliary mounting block is provided with a through hole and is connected with the bearing column through a bolt, the lower end of the V-shaped plate spring is provided with a through hole, and the V-shaped plate spring is fixedly connected with the connecting rod through a bolt. Fig. 6 (a) shows that when the stiffness switch is turned off, the V-shaped leaf spring is in a linear state, and in this state, the V-shaped leaf spring provides positive stiffness to the adjustable dynamic stiffness changing mechanism, and the stiffness analytical formula is:
the V-shaped plate spring and the positive-stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic high-stiffness structural form. Fig. 6 (b) shows that when the stiffness switch is turned on, the V-shaped leaf spring is in a bending state, and in this state, the V-shaped leaf spring provides negative stiffness in the axial direction of the load-bearing column for the adjustable dynamic stiffness-changing mechanism, and the analytical formula of the stiffness is as follows:
the V-shaped plate spring and the positive-stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic low-stiffness structural form.
FIG. 7 is a graph comparing the V-shaped plate spring force-displacement curves under two stiffness conditions in the present invention. The slope of the force-displacement curve represents the rigidity, so that the V-shaped plate spring force-displacement curve represents the rigidity of the V-shaped plate spring under the two rigidity conditions. When the curve 1 is the rigidity switch is closed, the observation of the curve shows that when the load bearing column is subjected to displacement and the U changes, the slope of the curve is continuously increased, namely the rigidity of the V-shaped plate spring is continuously increased, and the V-shaped plate spring provides positive rigidity at the moment, so that the device meets the high-rigidity state. When the curve 2 is the rigidity switch is opened, the observation of the curve shows that when the bearing column is near the balance position and U is more than-1 and less than 1, the slope of the curve is a negative value, namely the rigidity of the V-shaped plate spring is a negative value, at the moment, the V-shaped plate spring provides negative rigidity, the negative rigidity provided by the V-shaped plate spring is superposed with the positive rigidity of the positive rigidity plate spring, the near the balance position of the bearing column can be adjusted to be in a quasi-zero rigidity state, and the device meets the low rigidity state.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not to be construed as limiting the claims.
The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the foregoing, the description is not to be taken in a limiting sense.
Claims (10)
1. The utility model provides an adjustable dynamic variable rigidity device of six degrees of freedom based on concentric circles which characterized in that: comprises that
The upper platform is used for contacting with a load, three first grooves and three second grooves are formed in the bottom surface of the upper platform, and the circumference where the three first grooves on the inner side are located and the circumference where the three second grooves on the outer side are located are concentric circles; and
the mounting angle seat comprises an upper mounting angle seat and a lower mounting angle seat which have the same structure, each first groove and each second groove are respectively connected with the upper mounting angle seat through countersunk bolts, and the bottom of the upper mounting angle seat is connected with a bearing column of the adjustable dynamic variable stiffness mechanism; and
the adjustable dynamic stiffness changing mechanism comprises a bearing column, an upper cover, a positive stiffness plate spring, an auxiliary mounting block, a support beam mounting plate I, a support beam mounting plate II, a connecting rod, a stiffness switch, a V-shaped plate spring, a cylindrical shell and a lower cover, wherein the upper cover and the lower cover are respectively mounted at two ends of the cylindrical shell, and the bearing column penetrates through the upper cover and is arranged in an inner cavity of the cylindrical shell; the bearing column positioned in the inner cavity of the cylindrical shell is sequentially connected with the positive-stiffness plate spring, the V-shaped plate spring and the positive-stiffness plate spring, and the other end of the positive-stiffness plate spring is connected with the cylindrical shell through an auxiliary mounting block; the other end of the V-shaped plate spring is fixedly connected with the connecting rod; the lower end of the connecting rod is connected with the rigidity switch, the two sides of the connecting rod are respectively provided with the second supporting beam mounting plate, the two ends of the supporting beam are respectively welded with the first supporting beam mounting plate and the second supporting beam mounting plate, and the lower end of the first supporting beam mounting plate is fixedly connected with the cylindrical shell through a bolt; and
the lower platform is used for contacting with a foundation, three third grooves and three fourth grooves are formed in the top surface of the lower platform, the circumference where the three third grooves are located on the inner side and the circumference where the three fourth grooves are located on the outer side are concentric circles, and the third grooves and the fourth grooves are connected with the lower mounting angle seat through countersunk bolts.
2. The six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles as claimed in claim 1, wherein: the centers of the upper platform and the lower platform are on a vertical line, the diameter of the circumference where the first groove is located is the same as that of the circumference where the third groove is located, and the diameter of the circumference where the second groove is located is the same as that of the circumference where the fourth groove is located.
3. The concentric circle based six degree of freedom adjustable dynamic variable stiffness device of claim 1, wherein: the main body of the upper platform comprises a central platform, connecting plates and a hexagonal platform, the central platform and the hexagonal platform are concentrically arranged, a plurality of connecting plates are uniformly distributed and connected in the circumferential direction of the central platform, and the other ends of the connecting plates are fixedly connected with the inner sides of the hexagonal platform; the outer side edge line of the hexagonal platform is hexagonal, and the inner side edge is circular.
4. The six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles as claimed in claim 1, wherein: the main body of the lower platform comprises a central platform, connecting plates and a hexagonal platform, the central platform and the hexagonal star platform are concentrically arranged, a plurality of connecting plates are uniformly distributed and connected in the circumferential direction of the central platform, and the other ends of the connecting plates are fixedly connected with the inner side of the hexagonal star platform; the outer side edge line of the hexagonal star platform is a regular hexagonal star shape, and the inner side edge of the hexagonal star platform is circular.
5. The six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles as claimed in claim 1, wherein: go up the mount angle seat and include the cylinder and be located the scarf of cylinder top one side, all set up threaded hole on cylinder and the scarf.
6. The six-degree-of-freedom adjustable dynamic variable stiffness device based on concentric circles as claimed in claim 5, wherein: each first groove and each second groove are respectively connected with the cylinder of the upper mounting angle base through countersunk bolts, and the chamfered surface of the upper mounting angle base is connected with the bearing column of the adjustable dynamic variable stiffness mechanism through a stud; and the third groove and the fourth groove are connected with the cylinder of the lower mounting angle seat through countersunk bolts, and the chamfered surface of the lower mounting angle seat is connected with the lower cover of the adjustable dynamic variable stiffness mechanism through a stud.
7. The concentric circle based six degree of freedom adjustable dynamic variable stiffness device of claim 1, wherein: the upper end of the upper cover is provided with a through hole with the diameter larger than that of the bearing column; and four threaded holes are formed in the circumference of the lower end of the upper cover and are respectively connected with the cylindrical shell through screws.
8. The concentric circle based six degree of freedom adjustable dynamic variable stiffness device of claim 1, wherein: two ends of the positive-rigidity plate spring are welded with the auxiliary mounting blocks, and through holes respectively used for being connected with the bearing column and the cylindrical shell are formed in the auxiliary mounting blocks at the two ends of the positive-rigidity plate spring; the upper end of the V-shaped plate spring is welded with the auxiliary mounting block, the auxiliary mounting block at the upper end of the V-shaped plate spring is connected with the bearing column through a screw, and the lower end of the V-shaped plate spring is fixedly connected with the connecting rod through a bolt.
9. The concentric circle based six degree of freedom adjustable dynamic variable stiffness device of claim 1, wherein: when the rigidity switch is closed, the V-shaped plate spring is in a linear state, the V-shaped plate spring provides positive rigidity for the adjustable dynamic rigidity changing mechanism, and the rigidity analytic formula is as follows:
the V-shaped plate spring and the positive stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic high-stiffness structural form;
when the rigidity switch is opened, the V-shaped plate spring is in a bending state, the V-shaped plate spring provides negative rigidity in the axial direction of the bearing column for the adjustable dynamic rigidity changing mechanism, and the rigidity analytic expression is as follows:
the V-shaped plate spring and the positive stiffness plate spring meet the stiffness superposition principle, so that the adjustable dynamic stiffness changing mechanism is in an adjustable dynamic low-stiffness structural form.
10. The concentric circle based six degree of freedom adjustable dynamic variable stiffness device of claim 1, wherein: the adjustable dynamic variable stiffness mechanism comprises an adjustable dynamic variable stiffness mechanism I, an adjustable dynamic variable stiffness mechanism II, an adjustable dynamic variable stiffness mechanism III, an adjustable dynamic variable stiffness mechanism IV, an adjustable dynamic variable stiffness mechanism V and an adjustable dynamic variable stiffness mechanism VI, wherein any two adjustable dynamic variable stiffness mechanisms are parallel or vertical to each other in space; the first groove comprises a first groove I, a second groove II and a third groove, the second groove comprises a first groove I, a second groove II and a third groove III, the third groove comprises a first groove I, a second groove II and a third groove III, the fourth groove comprises a first groove I, a second groove II and a third groove III, the upper end and the lower end of the first adjustable dynamic variable stiffness mechanism are assembled in the first groove I and the fourth groove I respectively through the upper mounting angle seat and the lower mounting angle seat, the upper end and the lower end of the second adjustable dynamic variable stiffness mechanism are assembled in the first groove I and the third groove I respectively through the upper mounting angle seat and the lower mounting angle seat, the upper end and the lower end of the third adjustable dynamic variable stiffness mechanism are assembled in the second groove II and the fourth groove II respectively through the upper mounting angle seat and the lower mounting angle seat, the upper end and the lower end of the fourth adjustable dynamic variable stiffness mechanism are assembled in the second groove II and the third groove II, the upper end and the lower mounting angle seat are assembled in the third groove II and the upper mounting seat respectively through the upper mounting seat and the third groove, and the upper mounting seat and the lower mounting seat of the adjustable dynamic variable stiffness mechanism, and the upper mounting seat are assembled in the adjustable dynamic variable stiffness mechanism respectively through the second groove.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210989928.1A CN115523257A (en) | 2022-08-18 | 2022-08-18 | Six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210989928.1A CN115523257A (en) | 2022-08-18 | 2022-08-18 | Six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles |
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| Publication Number | Publication Date |
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| CN115523257A true CN115523257A (en) | 2022-12-27 |
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| CN202210989928.1A Pending CN115523257A (en) | 2022-08-18 | 2022-08-18 | Six-freedom-degree adjustable dynamic variable stiffness device based on concentric circles |
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| Country | Link |
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| CN (1) | CN115523257A (en) |
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