CN114148364A

CN114148364A - Rigidity-controllable magnetorheological rubber node with failure safety characteristic

Info

Publication number: CN114148364A
Application number: CN202111533102.6A
Authority: CN
Inventors: 孙帅帅; 巩宁; 龚兴龙; 张世武
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2022-03-08
Anticipated expiration: 2041-12-15
Also published as: CN114148364B

Abstract

The invention discloses a rigidity-controllable magnetorheological rubber node with a failure safety characteristic, which can change the elastic modulus of a magnetorheological elastomer by applying current so as to change the radial rigidity of the node. Specifically, the rigidity-controllable magnetorheological rubber node mainly comprises a magnetorheological elastomer (MRE), an excitation coil, a node outer sleeve, a node mandrel, a magnetic shoe, a steel ring and other parts. The magnetic shoe is used for providing an initial magnetic field, so that the rubber node shows high rigidity in an uncontrolled state, and firstly, the high-speed stability requirement of the train is met, and the fault safety characteristic is achieved; when the excitation coil is electrified, an electromagnetic field opposite to the magnetic shoe is generated, and the magnetic field intensity passing through the magnetorheological elastomer is reduced, so that the radial rigidity of the node is reduced, and the passing requirement of a curve of a train is met. The rubber node belongs to semi-active control, and has the characteristics of low energy consumption, compact and simple structure, high safety, universal replacement with the existing passive train rubber node and the like.

Description

Rigidity-controllable magnetorheological rubber node with failure safety characteristic

Technical Field

The invention relates to the technical field of rubber nodes for trains, in particular to a rigidity-controllable magnetorheological rubber node with a fault safety characteristic.

Background

With the rapid development of high-speed railways, the research on the problems of stability, comfort, safety and the like of high-speed railways becomes more and more critical. The requirements on the rigidity of the bogie when the train runs in a straight line and passes through a curve are contradictory. The bogie is mainly required to have higher rigidity to ensure the stability and safety of the train when the train runs at high speed in a straight line; when the train passes through a curve, the longitudinal rigidity of the bogie system is required to be smaller so as to be convenient for steering, and therefore the curve passing performance of the railway locomotive is improved. Therefore, the invention provides a rigidity-controllable magnetorheological rubber node with a fail-safe characteristic. The rubber node is a device for connecting a bogie frame and a wheel pair rotating arm on a locomotive. The use of such a rubber node enables elastic positioning to limit longitudinal and lateral movement of the wheel pair. The rigidity value has a crucial influence on the curve passing performance and high-speed stability of the train.

The magneto-rheological technology is a typical semi-active control technology, and the technology is based on magneto-rheological intelligent materials and mainly comprises a magneto-rheological elastomer and magneto-rheological fluid. The magnetorheological elastomer has the advantages of adjustable rigidity, stable performance, quick response, good reversibility, no sedimentation, no need of considering sealing and the like. The magnetorheological elastomer generally has two working states, and shows small rigidity when no control magnetic field is applied to the outside, and shows large rigidity when a magnetic field is applied to the outside. Through design and optimization, the damping characteristic or the rigidity characteristic of the magnetorheological elastomer device can be adjusted by applying the change of an external current. Therefore, the magnetorheological elastomer technology is used for developing the rigidity-variable train wheel pair positioning node technology.

In practical application, the rigidity requirements of the elastic positioning node are opposite when the train runs on a straight road at a high speed and runs on a curve, so that the rigidity requirements are difficult to obtain in the design of the same mechanism. On one hand, the small longitudinal rigidity of the wheel set system is beneficial to the radial adjustment of the wheel set, the curve passing capacity is improved by utilizing self-steering, and the wheel-rail abrasion and the wheel-rail noise of the train can be effectively reduced. On the other hand, a high-speed motor train unit train usually runs at a speed of 200km/h or more, at the moment, the train generates violent serpentine motion, and the serpentine motion is restrained by longitudinal positioning rigidity of wheel sets as large as possible to ensure the high-speed stability of the train. In conclusion, the passive rubber node with invariable rigidity can hardly meet the requirements of excellent both curve running and straight running performance. Therefore, it is very critical to develop an elastic rubber node with adjustable rigidity to meet the requirements of trains on different operation road sections requiring different rigidities. In order to solve the problem, the invention provides a rigidity-controllable magnetorheological rubber node with a failure safety characteristic. The novel rubber node can provide a solution for different rigidity requirements when driving in a straight line and a curve.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the rigidity requirements of the bogie when the train runs on a linear track and a curve section are different, which is particularly characterized in that the train needs to improve the longitudinal positioning rigidity to keep the stability when the train runs on a straight track at a high speed, and meanwhile, the train needs to reduce the longitudinal positioning rigidity of a wheel set to adapt to the passing of a curve. The existing passive rubber node can not have the two rigidity requirements, and in order to solve the defects of the existing rubber node, the invention provides the rigidity-controllable magnetorheological rubber node with the failure safety characteristic. The node can keep high rigidity when the train normally runs on a linear track to ensure high-speed stability of the train, and rigidity is reduced when the train needs to turn, so that abrasion of wheel sets and rails is improved, and operation and maintenance cost is reduced.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a rigidity-controllable magnetorheological rubber node with a failure safety characteristic comprises a magnetorheological elastomer, a steel ring, a magnetic shoe, a node outer sleeve, an excitation coil and a node mandrel. The node mandrel is positioned at the most central position of the rubber node, the steel ring is in interference fit with three sections of cylindrical surfaces of the node mandrel, the excitation coil is wound between coil grooves of the node mandrel, the magnetorheological elastomer is poured between gaps of the steel ring and can generate radial deformation, the magnetic shoe is assembled in the steel ring in an interference fit manner to form a whole with the steel ring and the magnetorheological elastomer, the node outer sleeve is positioned at the outermost layer of the rubber node, and the inner wall of the node outer sleeve is in interference fit with the steel ring; preferably, the rigidity-controllable magnetorheological rubber nodes are integrally arranged in a left-right symmetrical mode.

Further, the node mandrel is a shaft body having circumferential sections of different diameters. The excitation coil is arranged and wound between the reserved coil slots of the node mandrel. The magnetorheological elastomer is poured between gaps formed by the multiple layers of steel rings, and the inner surface and the outer surface of the magnetorheological elastomer are fixedly connected with the steel rings after being solidified.

Furthermore, the magnetorheological elastomer is poured in the steel ring structure, and the cured magnetorheological elastomer steel ring structure and the magnetic shoe are assembled into a whole in an interference manner.

The rigidity-controllable magnetorheological rubber nodes with the fail-safe characteristic are preferably arranged in a left-right symmetrical mode on the whole.

Further, the magnetorheological elastomer is of a multilayer structure. The magnetic shoe is arranged between the steel ring structures, the magnetizing direction is radial, the magnetorheological elastomer is subjected to the composite excitation of the magnetic shoe and the coil, and the size of the magnetic field is controlled by the current size and the direction of the excitation coil, so that the size of the node rigidity is changed.

Further, an initial magnetic field is provided by the magnetic shoe when the excitation coil is not energized. The node core shaft, the steel ring, the magnetic shoe, the magnetorheological elastomer and the node outer sleeve return to the core shaft to form a closed magnetic circuit, so that the magnetorheological elastomer keeps high rigidity, the whole rubber node shows radial high rigidity, and the high-speed stability requirement and the fault safety characteristic of a train are met.

Further, a current is applied to the exciting coil to generate an electromagnetic field in a direction opposite to the magnetic shoe. The rigidity of the magnetorheological elastomer is reduced, so that the radial rigidity of the integral rubber node is reduced by electrifying, and the requirement on the passing performance of a train curve is met.

The magnetic shoe is arranged in the middle of the steel ring structure, provides an initial magnetic field along the radial direction, returns to the mandrel through the mandrel, the magnetorheological elastomer, the magnetic shoe and the node sleeve to form a closed internal magnetic circuit, enables ferromagnetic particles in the magnetorheological elastomer to form an interaction force, and shows large rigidity.

The excitation coil is arranged between coil grooves of the node core shaft, the magnetic shoe provides a magnetic field under the condition that the excitation coil is not electrified, the magnetorheological elastomer shows high rigidity under the action of a strong magnetic field, the rubber node integrally shows radial high rigidity, after the excitation coil is electrified, the coil generates a radial magnetic field opposite to the direction of the magnetic shoe, and the magnetic field strength of the magnetorheological elastomer is weakened, so that the elastic modulus of the magnetorheological elastomer is reduced, the integral radial rigidity of the node is reduced, and the node has small rigidity.

The invention has the beneficial effects that:

the invention provides a rigidity-controllable magnetorheological rubber node with a failure safety characteristic, aiming at the problem that the existing common rubber node can not simultaneously meet the contradictory rigidity requirement of a train on a wheel pair elastic positioning node in a straight road section and a curve road section. The design can realize that the train provides large rigidity to ensure the high-speed stability of the train when the train runs at a high speed in a straight line, and simultaneously changes the rigidity into small rigidity to meet the requirement of curve trafficability when the train passes through a curve. Meanwhile, the appearance size and the installation size of the novel variable-rigidity rubber node provided by the invention are designed according to the existing train positioning node, and the novel variable-rigidity rubber node can be interchanged with the original rubber node of the train, so that the practicability is high. In addition, the rubber node provided by the invention has high rigidity in an initial state without control, and can ensure the high-speed stability of a train under the condition of node control failure, thereby having the failure safety characteristic.

Drawings

FIG. 1 is a front view, in cross section, of an embodiment of the present invention;

FIG. 2 is a left side view of the structure of the embodiment of the present invention.

Wherein, 1-node mandrel, 2-steel ring, 3-excitation coil, 4-magnetic shoe, 5-magnetic rheological elastomer, 6-node coat, rubber node are installed and arranged symmetrically, the dotted line and arrow indicate the magnetic path direction in the section.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments. The following examples are only for explaining the present invention, the scope of the present invention shall include the full contents of the claims, and the full contents of the claims of the present invention can be fully realized by those skilled in the art through the following examples.

As shown in fig. 1, the rigidity-controllable magnetorheological rubber node with the fail-safe characteristic of the invention comprises a node mandrel 1, a steel ring 2, an excitation coil 3, a magnetic shoe 4, a magnetorheological elastomer 5, a node outer sleeve 6 and the like. The node mandrel 1 is located at the most central position of the rubber node, the steel ring 2 is in interference fit with three sections of cylindrical surfaces of the node mandrel 1, the magnet exciting coil 3 is wound between coil grooves of the node mandrel 1, the magnetorheological elastomer 5 is poured between gaps of the steel ring 2 and can generate radial deformation, the magnetic shoe 4 is assembled in the steel ring 2 in an interference fit mode and forms a whole with the steel ring 2 and the magnetorheological elastomer 5, the node outer sleeve 6 is located on the outermost layer of the rubber node, and the inner wall of the node outer sleeve is in interference fit with the steel ring 2.

Fig. 2 is a left side view of the structure of the embodiment of the present invention, from which the radial positions of the components and the arrangement of the magnetic shoes can be more clearly seen. The outer shell 6, the steel ring 2, the magnetorheological elastomer 5, the magnetic shoe 4 and the node mandrel 1 are sequentially arranged from outside to inside in the radial direction, wherein the steel ring 2 and the magnetorheological elastomer 5 are arranged at intervals.

The principle that the rigidity is controllable is that the magnetic shoe 4 is used for providing an initial magnetic field, so that the rubber node shows large rigidity in a non-control state, and the high-speed stability requirement of the train is met firstly, and the fault safety characteristic is realized; when the excitation coil is electrified, a magnetic field direction opposite to the magnetic field of the initial magnet is generated, and the magnetic field intensity penetrating through the magnetorheological elastomer is reduced, so that the radial rigidity of the rubber node is reduced by electrifying, the characteristic of negative change of the rigidity of the node is realized, and the passing requirement of a train curve is met. The concrete implementation is as follows: when the excitation coil 3 is not electrified, the magnetic shoe 4 provides an initial radial magnetic field, a magnetic field loop in a section plane is shown as a lower arrow direction in fig. 1, and a closed magnetic circuit passing through the magnetic shoe 4, the steel ring 2, the magnetorheological elastomer 5, the node mandrel 1, the node outer sleeve 6 and other components is formed in the section plane. The elastic modulus of the magnetorheological elastomer 5 is increased under an initial strong magnetic field, and the integral rubber node has large radial rigidity; when the excitation coil 3 is electrified, an electromagnetic field in the direction opposite to the initial magnetic field of the magnetic shoe is generated, the magnetic field intensity passing through the magnetorheological elastomer 5 is weakened, the elastic modulus is reduced to generate small rigidity, and the whole rubber node has small radial rigidity, so that the requirement of the trafficability characteristic of a curve of a train is met. The nodes are mounted between the train bogie and the axleboxes to provide a set of longitudinal positioning stiffness between the jibs.

The joint mandrel 1 is of a bilaterally symmetrical revolving body structure, is made of No. 10 steel for ensuring good magnetic conduction, is connected with a bogie frame through a fork-shaped structure, and is mainly used for transmitting longitudinal force and transverse force of a train wheel pair. The reserved coil grooves of the node mandrel 1 are two sections of circular grooves with the same width and depth, and are symmetrically arranged in the middle of the node mandrel 1 in the left-right direction and used for winding and positioning the excitation coil 3.

The steel ring 2 comprises three groups of rings made of No. 10 steel, each group of rings comprises seven thin-wall rings with the same width and gradually increased diameter, the wall thickness of each steel ring is 2.5mm, the diameters of the inner walls of the seven steel rings are 64mm, 72mm, 80mm, 88mm, 99mm, 107mm and 115mm in sequence, the seven thin-wall rings are respectively arranged on three cylindrical surfaces of the node mandrel 1 in the axial direction in an interference mode, and the seven thin-wall rings and the magnetorheological elastomers are arranged in a staggered mode to increase the rigidity of the rubber nodes and improve the magnetic conduction effect.

The magnet exciting coil 3 is in a ring shape, is made by winding a copper enameled wire with the diameter of 0.51mm in a coil groove of the node mandrel 1 and is used for generating a controllable axial magnetic field, and the initial magnetic field generated by the magnetic shoe 4 can be reduced by electrifying, so that the reduction of the rigidity of the rubber node is realized to ensure the good curve passing performance of the train.

Magnetic shoe 4 contain three groups of magnetic shoes, be the neodymium iron boron material, trade mark N38H, wherein every group magnetic shoe comprises 24 magnetic shoes again, its mounted position and mode of arrangement are shown in figure 2, magnetic shoe 4 installs in the fourth circle steel ring of steel ring 2 and the clearance department of fifth circle steel ring, evenly arranges along the circumference, produces a radial magnetic field. The magnetic pole directions of the magnetic shoes at the two ends are an outer surface N pole and an inner surface S pole, and the magnetic shoes in the middle group are an outer surface S pole and an inner surface N pole opposite to the outer surface N pole. Three groups of magnetic shoes can provide an initial magnetic field, so that the rubber node still has high rigidity when no electricity exists and has a fault safety characteristic.

The magnetorheological elastomer 5 is of a multilayer structure. The multilayer magnetorheological elastomer 5 is integrated with the steel ring 2 by casting. Specifically, the magnetorheological elastomer 5 is annular, is composed of a magnetorheological elastomer with the thickness of 5 layers being 1.5mm, and is prepared by mixing PDMS (polydimethylsiloxane) and carbonyl iron powder and pouring the mixture into a whole at a gap of the steel ring 2. The controllable rigidity under the magnetic field is characterized by controllable rigidity under the magnetic field, thereby realizing controllable change of radial rigidity of rubber nodes under different currents.

The 6 tubular structures of node overcoat adopts 10 # steel to make, is located the outermost circle of node, and the inner wall and the 2 interference fit of steel ring of node overcoat 6, outer wall pass through fixed orifices and axle box location rocking arm connection, mainly used realizes the elastic positioning of wheel pair.

The invention has not been described in detail and is part of the common general knowledge of a person skilled in the art. The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and the preferred embodiments are not exhaustive and do not limit the invention to the precise embodiments described. Various modifications and improvements of the technical solution of the present invention may be made by those skilled in the art without departing from the spirit of the present invention, and the technical solution of the present invention is to be covered by the protection scope defined by the claims.

Claims

1. The utility model provides a controllable magnetic current becomes rubber node of rigidity with fail safe characteristic, includes node dabber (1), steel ring (2), excitation coil (3), magnetic shoe (4), magnetic current becomes elastomer (5) and node overcoat (6), its characterized in that: the node mandrel (1) is located at the most central position of a rubber node, the steel ring (2) is in interference fit with three sections of cylindrical surfaces of the node mandrel (1), the magnet exciting coil (3) is wound between coil grooves of the node mandrel (1), the magnetorheological elastomer (5) is poured between gaps of the steel ring (2) and can generate radial deformation, the magnetic shoes (4) are assembled in the steel ring (2) in an interference fit mode and form a whole with the steel ring (2) and the magnetorheological elastomer (5), the node outer sleeve (6) is located on the outermost layer of the rubber node, and the inner wall of the node outer sleeve is in interference fit with the steel ring (2); preferably, the rigidity-controllable magnetorheological rubber nodes are integrally arranged in a left-right symmetrical mode.

2. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the magnetorheological elastomer (5) is of a multilayer structure.

3. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the magnetizing direction of the magnetic shoe is radial, the magnetorheological elastomer (5) is subjected to the composite excitation of the magnetic shoe (4) and the excitation coil (3), and the size of the magnetic field is controlled by the current size and the direction of the excitation coil (3), so that the size of the node rigidity is changed.

4. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: when the excitation coil (3) is not electrified, the magnetic shoe (4) provides an initial magnetic field, and a closed magnetic circuit passing through the magnetic shoe (4), the steel ring (2), the magnetorheological elastomer (5), the node mandrel (1) and the node outer sleeve (6) is formed in a section plane.

5. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 4, wherein: a current is applied to the excitation coil (3) to generate an electromagnetic field in a direction opposite to the magnetic shoe (4).

6. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the coil slots reserved in the node mandrel (1) are two sections of circular slots with the same width and depth, and are symmetrically arranged in the middle of the node mandrel (1) in the left-right direction and used for winding and positioning the excitation coil (3).

7. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the steel ring (2) comprises three groups of circular rings, each group of circular rings comprises seven circular rings with the same width and gradually increased diameter, the circular rings are respectively arranged on three sections of cylindrical surfaces on the axial direction of the node mandrel (1) in an interference fit mode and are arranged with the magnetorheological elastomers (5) in a staggered mode.

8. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the excitation coil (3) is in a ring shape, is wound in a coil groove of the node core shaft (1) and is used for generating a controllable axial magnetic field.

9. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: magnetic shoe (4) contain three groups of magnetic shoes, wherein lie in a set of magnetic shoes of node dabber (1) intermediate position and two sets of magnetic shoes at both ends and have opposite magnetic pole direction, three groups of magnetic shoes are all installed in the clearance department of the 4 th circle steel ring of steel ring (2) and the 5 th circle steel ring, evenly arrange along the circumference, produce an initial radial magnetic field.

10. The stiffness controllable magnetorheological rubber node having a failsafe characteristic of claim 1, wherein: the magnetorheological elastomer (5) is annular and is prepared by a mode of casting and forming in a gap of the steel ring (2), and the magnetorheological elastomer and the steel ring (2) form a whole after being cured; preferably, the node outer sleeve (6) is of a cylindrical structure and is positioned at the outermost ring of the node, and the inner wall of the node outer sleeve is in interference fit with the steel ring (2).