CN107985329A - Rigidity adjustable fire axle box positioning elastic node based on magnetic rheology elastic body - Google Patents

Abstract

The invention discloses a magneto-rheological elastomer-based train axlebox with adjustable stiffness for positioning elastic nodes. By adjusting the magnitude of the applied current, the elastic modulus of the magnetorheological elastomer is changed to control the axial and radial stiffness of the elastic nodes. In order to ensure that the elastic nodes provide greater stiffness when the train is running on a straight track to ensure high-speed and stable running of the train, and when the train is running on a curve, the elastic nodes provide smaller stiffness to ensure that the train has good curve passing performance. Including magnetorheological elastomers, excitation coils, node mandrels and node jackets; the node mandrels are shafts with coil grooves, and the excitation coils are wound in the grooves of the node mandrels to control the magnetic field of the magnetorheological elastomers . One surface of the magnetorheological elastomer is vulcanized on the node mandrel of the non-groove part, and the other surface is vulcanized on the inner wall of the node jacket. The structure is compact and simple, consistent with the original rubber joint structure of the train, easy to realize and replace the existing passive rubber joints on the train, and has strong feasibility and practicability.

Description

Locating Elastic Nodes of Axleboxes with Adjustable Stiffness Based on Magnetorheological Elastomers

technical field

The invention relates to the technical field of a magneto-rheological elastomer-based stiffness-adjustable device, in particular to a magneto-rheological elastomer-based stiffness-adjustable train axle box positioning elastic node.

Background technique

The axle box positioning of the train has a crucial influence on the running stability and curve passing performance of the train. The positioning methods of axle boxes of trains mainly include rotary arm type, pedestal type, pull plate type, pull rod type and rubber element positioning methods. The above positioning methods can achieve good results under the premise of correct design structure and selection of reasonable parameters. The positioning function is only a certain difference in its performance and durability when used. In most of the above positioning methods, there is a very important positioning element, which is a series of positioning rubber nodes. The rubber joint is a device used to connect the frame and the axle box link, or the axle box arm. The use of this rubber joint can limit the longitudinal and lateral relative displacement between the axle box and the frame while achieving elastic positioning.

In the process of train design, the stiffness selection of rubber joints has a crucial influence on the critical speed and curve passability of the train. The stiffness of rubber joints has completely opposite effects on critical speed and curve passing performance. It is also contradictory in design. On the one hand, the smaller longitudinal stiffness of the wheel set can enable the train to obtain good curve passing performance, and at the same time can greatly reduce the wheel-rail force, wheel-rail wear and wheel-rail noise of the train. In this way, when the train is running on a curve, the wheel set can be adjusted radially by using the self-guiding effect, thereby reducing the angle of attack of the wheel rim to the track and improving the curve passing performance of the vehicle. on the other hand. Modern running gear must reach a high speed of 200km/h or higher. In this way, it is necessary to ensure the stability of the train when it is running at high speed. The stability of high-speed driving needs to improve the longitudinal positioning stiffness of the wheel set as much as possible to strictly maintain the parallelism of the two wheels. To sum up, the design of the stiffness of the rubber joint is very important, and at the same time, it is difficult for the passive rubber joint with invariable stiffness to meet the different requirements for the stiffness of the rubber joint when driving in a curve and driving in a straight line.

Through the above analysis, it can be concluded that the development of an intelligent rubber joint with adjustable stiffness is crucial to improve the high-speed stability and curve passing ability of the train. To solve this problem, the present invention proposes an elastic rubber node for trains with adjustable stiffness based on magneto-rheological elastomers. Magnetorheological elastomers are smart materials with tunable stiffness. Under the condition of applying different magnetic fields, the magnetorheological elastomer can change its own stiffness rapidly and reversibly. This material provides the perfect solution for the different stiffness requirements of rubber joints on straights and curves. The rigidity-adjustable elastic node designed by the invention can provide greater longitudinal rigidity for a high-speed train to ensure its stability, and at the same time can reduce the longitudinal positioning rigidity of the train to improve its curve passing performance.

Contents of the invention

Existing passive rubber joints cannot meet the different requirements for joint positioning stiffness of trains running on curved roads and straight roads. The purpose of the present invention is to provide an elastic positioning joint with variable stiffness to solve this problem. When the vehicle is running at high speed, the node provides greater positioning stiffness, and when the vehicle passes through the curve at low speed, it provides a smaller wheel set positioning stiffness.

The present invention is achieved through the following technical solutions:

The elastic nodes of the train axlebox with adjustable stiffness based on magnetorheological elastomers, including magnetorheological elastomers, excitation coils, node mandrel 1 and node jacket; where,

Node mandrel one is a shaft body with a coil groove;

The excitation coil is wound in the groove of the node mandrel one;

The inner surface of the magnetorheological elastomer is vulcanized on the non-groove surface of the node mandrel one, and the outer surface is vulcanized on the inner surface of the node jacket. The stiffness characteristics of the magnetorheological elastomer are controlled by electromagnetic coils; the excitation coil Winding in the groove of node mandrel one, the strength of the electromagnetic field generated by the electromagnetic coil is controlled by the magnitude of the applied current, and the node mandrel one is installed in the node jacket, so that the node structure is compact.

Wherein, the magnetorheological elasticity is a cylindrical surface with a certain thickness, which is installed between the node mandrel 1 and the node jacket, and the node mandrel 1, the node jacket and the magnetorheological elastomer are solidly connected through vulcanization treatment to form a One.

Stiffness-adjustable train axlebox positioning elastic nodes based on magnetorheological elastomers, including magnetorheological elastomers, excitation coils, node mandrel two and node jackets, excitation coil windings with coil grooves and a node core Axis 2; the excitation coil is wound in the groove of the excitation coil winding body;

The excitation coil winding body is installed in the node casing, the node mandrel 2 is installed inside the excitation coil winding body, the outer surface of the magnetorheological elastomer and the inner surface of the excitation coil winding body are vulcanized, and the inner surface and the outer surface of the node mandrel 2 vulcanized together.

Wherein, the excitation coil is wound on the excitation coil winding body, and the excitation coil winding body is fixed inside the node casing through an interference fit with the node casing; the magnetorheological elastomer is a cylindrical surface with a certain thickness, installed on the Between the winding body of the excitation coil and the second mandrel shaft of the node, after vulcanization treatment, the whole node is connected into a whole.

The principle of the present invention is that the present invention uses the property of the controllable stiffness of the magneto-rheological elastomer to design a novel elastic node for trains with adjustable stiffness. The elastic node described has two different structures. In the first structure, the elastic node is composed of magnetorheological elastomer, excitation coil, node mandrel and node jacket. Among them, the node mandrel is a specially designed shaft with a coil groove, and the excitation coil is wound in the groove of the node mandrel to control the magnetic field of the magnetorheological elastomer, thereby controlling the stiffness of the node. One surface of the magnetorheological elastomer is vulcanized on the node mandrel of the non-groove part, and the other surface is vulcanized on the inner wall of the node jacket. In the second structure, the elastic node includes a magneto-rheological elastic body, an excitation coil, a node mandrel, a node jacket and an excitation coil winding body. The excitation coil is wound in the groove of the excitation coil winding body, the excitation coil winding body is installed in the node jacket, the node mandrel is installed inside the excitation coil winding body, the outer surface of the magnetorheological elastomer and the inner surface of the excitation coil winding body Vulcanization, the inner surface and the outer surface of the node mandrel are vulcanized and solidified. Through the above two structural designs, the positioning stiffness of the node can be changed by adjusting the magnitude of the applied current to change the elastic modulus of the magnetorheological elastomer to control the axial and radial stiffness of the elastic rubber node, so as to ensure that the train is running on a straight track. The elastic nodes provide greater stiffness to ensure the train runs stably at high speed. When the train is running on a curve, the elastic nodes provide smaller stiffness to ensure that the train has a good curve passing performance.

The advantage of the present invention compared with prior art is:

The invention utilizes the advantages of the controllable stiffness of the magneto-rheological elastic body to design a novel train axle box positioning node with adjustable stiffness. This design can meet the different requirements for the positioning stiffness of the axle box when the train is running on different track conditions. Specifically, the new node can provide large stiffness to meet its stability requirements when the train is running at high speed, and can provide small stiffness to improve its curve passability when the train is going through a curve. In addition, the external dimensions and installation dimensions of the new axle box positioning node are basically the same as the original positioning node of the train. When installing and using the new type of node, there is no need to modify the original design, which is easy to implement and has strong practicability. Simultaneously, the present invention is semi-active control, and energy consumption is little.

Description of drawings

FIG. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

Fig. 2 is a schematic structural diagram of Embodiment 2 of the present invention.

Figure 3 is a diagram of the tensile test results of rubber nodes using a universal material tensile machine (MTS).

The meanings of reference signs in the figure are: 1 is the node jacket, 2 is the excitation coil, 3 is the magnetorheological elastomer, 4A is the node mandrel 1, 4B is the node mandrel 2, 5 is the magnetic field, and 6 is the excitation coil winding body , 7 is a pull bar.

Detailed ways

Embodiment 1

As shown in FIG. 1 , the axlebox positioning node for trains with adjustable stiffness based on magnetorheological elastomers includes magnetorheological elastomers 3 , excitation coils 2 , node mandrel 4A and node jacket 1 . The node mandrel-4A is a shaft body with a coil groove. The excitation coil 2 is wound in the groove of the node mandrel-4A. The magnetorheological elastomer 3 is a cylindrical structure with a certain thickness. Insert the cylindrical magnetorheological elastomer 3 onto the coiled node mandrel 4A. The excitation coil 2 can be a single-stage coil or a multi-stage coil. Vulcanize the node mandrel-4A covered with the magnetorheological elastomer 3, so that the magnetorheological elastomer 3 and the node mandrel-4A can be tightly connected (other methods can also be used to make the node mandrel-4A and the magnetic flow variable elastic body 3 tight junctions). Finally, install the node mandrel-4A covered with the magnetorheological elastomer 3 into the cylindrical node outer casing 1 . And the entire positioning node is vulcanized so that the magnetorheological elastomer 3 and the inner wall of the node jacket 1 are fixedly connected (other methods of fixing are also available). The length of the node mandrel 4A of the positioning node of the axle box is greater than the length of the node jacket 1 . Both ends of the node mandrel-4A protrude out of the node jacket 1 . Connected by hinges and frames. The node jacket 1 of the positioning node is connected with the rotating arm or the tie rod 7 by means of welding or the like.

When the vehicle is running on a straight track at high speed, the vehicle transmits the speed information to the positioning node controller, and the node controller sends a large current control to the node after determining to generate a magnetic field 5 as shown in Figure 1. At this time, the MRE Under the action of the magnetic field, the body's own stiffness increases, thereby increasing the stiffness of the axle box positioning node to ensure the stability of the vehicle at high speed. When the vehicle is running on a curved track at a low speed, the controller of the axle box positioning node collects the vehicle speed, and judges the required stiffness value of the node according to the vehicle speed, and sends a small stiffness control to the positioning node. Thereby ensuring the curve passability of the vehicle, reducing the impact angle of the train's wheel rim to the track, wheel-rail force and wheel-rail wear.

Embodiment 2

As shown in Figure 2, the train axlebox positioning node with adjustable stiffness based on magnetorheological elastomers includes magnetorheological elastomers 3, excitation coils 2, node mandrel 2 4B, node jacket 1 and excitation coil winding body 6 . The node mandrel 2 4B should be made of high magnetic permeability material. The magnetorheological elastomer 3 is a cylindrical structure with a certain thickness. Insert the cylindrical magnetorheological elastomer 3 into the node mandrel 2 4B. Vulcanize the node mandrel 2 4B covered with the magnetorheological elastomer, so that the magnetorheological elastomer 3 and the node mandrel 2 4B can be tightly connected (other methods can also be used to make the node mandrel 2 4B and the magnetorheological elastic body 3 tight junction). The excitation coil winding body 6 is a cylindrical structure with a groove, and the excitation coil 2 is wound in the groove of the excitation coil winding body 6 . The excitation coil 2 can be a single-stage coil or a multi-stage coil. Put the node mandrel 2 4B covered with the magnetorheological elastomer 3 into the inner hole of the excitation coil winding body 6, and vulcanize this whole structure, so that the magnetorheological elastomer 3 and the excitation coil winding body The inner wall of 6 can be tightly connected (other methods can also be used to make the node mandrel 2 4B and the magnetorheological elastomer 3 tightly connected). Finally, the excitation coil winding body 6 covered with the magnetorheological elastomer 3 is installed in the cylindrical node casing 1 . The matching method between the excitation coil winding body 6 and the node casing 1 is an interference fit. The length of the node mandrel 2 4B of the positioning node of the axle box is greater than the length of the node jacket 1 . The two sections of node mandrel 2 4B stretch out outside the node jacket 1 . Connected by hinges and frames. The node jacket 1 of the positioning node is connected with the rotating arm or the tie rod 7 by means of welding or the like.

The control mode of the positioning node (implementation 2) is the same as that of the first embodiment. The positioning node determines whether the stiffness of the axlebox positioning node is large or small according to the speed of the vehicle by collecting the vehicle speed.

Figure 3 is a diagram of the tensile test results of rubber nodes using a universal material tensile machine (MTS). During the experiment, the axial displacement of the rubber nodes was controlled to be ±0.2mm and the vibration frequency was 1Hz. Observing the experimental results, when the excitation current of 2A, 1A, and 0A is applied, the corresponding node stiffness relationship is 2A>1A>0A, which shows that when the excitation current is larger, the node stiffness is larger.

Claims (4)

1. The elastic node of the train axlebox with adjustable stiffness based on magnetorheological elastomer is characterized in that: it comprises magnetorheological elastomer (3), excitation coil (2), node mandrel one (4A) and node overcoat ( 1); where, Node mandrel one (4A) is a shaft body with a coil groove; The excitation coil (2) is wound in the groove of the node mandrel one (4A); The inner surface of the magnetorheological elastomer (3) is vulcanized on the non-groove surface of the node mandrel one (4A), the outer surface is vulcanized on the inner surface of the node jacket (1), and the magnetorheological elastomer (3) Stiffness characteristics are controlled by the electromagnetic coil; the excitation coil (2) is wound in the groove of the node mandrel one (4A), and the strength of the electromagnetic field generated by the electromagnetic coil is controlled by the magnitude of the applied current, and the node mandrel one (4A ) is installed in the node jacket (1), so that the node structure is compact. 2. The elastic joint of the train axlebox with adjustable stiffness based on magnetorheological elastomer according to claim 1, characterized in that: the magnetorheological elasticity (3) is a cylindrical surface with a certain thickness, installed on Between the node mandrel one (4A) and the node jacket (1), the node mandrel one (4A), the node jacket (1) and the magnetorheological elastomer (3) are solidly connected into one body through vulcanization treatment. 3. The elastic node of the train axlebox with adjustable stiffness based on magnetorheological elastomer is characterized in that: it includes magnetorheological elastomer (3), excitation coil (2), node mandrel two (4B) and node jacket ( 1), an excitation coil winding body (6) with a coil groove and a node mandrel 2 (4B); the excitation coil (2) is wound in the groove of the excitation coil winding body (6); The excitation coil winding body (6) is installed in the node casing (1), the node mandrel 2 (4B) is installed inside the excitation coil winding body (6), and the outer surface of the magnetorheological elastomer (3) and the excitation coil winding body The inner surface of (6) is vulcanized, and the inner surface and the outer surface of node mandrel two (4B) are vulcanized and solidly connected together. 4. The train axlebox positioning elastic node with adjustable stiffness based on magnetorheological elastomer according to claim 3, characterized in that: the excitation coil (2) is wound on the excitation coil winding body (6), and the excitation The coil winding body (6) is fixed inside the node casing (1) through an interference fit with the node casing (1); the magnetorheological elastomer (3) is a cylindrical surface with a certain thickness, and is installed on the excitation coil winding body Between (6) and node mandrel 2 (4B), after vulcanization treatment, the whole node is connected into a whole.