WO2020114064A1 - Current lead structure and superconducting magnet - Google Patents

Abstract

The present application relates to a current lead structure and a superconducting magnet. The current lead structure comprises a fixed connector, a movable connector, a deformation sealing assembly and a power control device; the power control device comprises a power assembly with an inner cavity, and the inner cavity is filled with an acting medium; and the power assembly, according to the acting medium or an acting force jointly acting on the inner cavity with an external force, drives the movable connector relative to a superconducting magnet shell to reciprocate between an on-position where the movable connector and the fixed connector are connected and an off-position where the movable connector and the fixed connector are separated. According to the current lead structure and the superconducting magnet, the movable connector moves to be connected to the fixed connector during excitation and demagnetization; the movable connector moves to be separated from the fixed connector after loop closing of a superconducting coil is finished; and the convenience of permanent current lead operation and the advantage that an extra heat transfer does not occur after temporary current leads are pulled out are taken into account. At the same time, the current lead structure is provided with a power control assembly for realizing automatic control over the connection and disconnection between the movable connector and the fixed connector, and the operation thereof is convenient.

Description

Current lead structure and superconducting magnet Technical field

The invention relates to the technical field of superconducting magnets, in particular to a current lead structure and superconducting magnets.

Background technique

Superconductivity refers to the property that the resistance of some substances drops to zero under certain temperature conditions (generally lower temperature), and the superconductivity of the material can be used to make superconducting magnets. Among them, the superconducting coil in the superconducting magnet is connected to the external circuit through the current lead to generate a magnetic field and store energy.

However, the common current leads are permanent current leads and temporary current leads. Among them, the permanent current lead is kept inside the magnet no matter during excitation or field reduction or after any operation is completed, so it is easy to generate additional heat conduction; while the temporary current lead is connected to the magnet during excitation and field reduction, but after completion It is pulled out, so it needs frequent manual insertion and removal during use, and the operation is complicated.

Summary of the invention

Based on this, a current lead structure and a superconducting magnet that are easy to operate and do not generate additional heat conduction are provided.

A current lead structure is assembled on a superconducting magnet. The current lead structure includes:

A fixed joint fixedly arranged on one of the internal structure of the cold screen of the superconducting magnet and the cold screen;

A movable joint arranged on the superconducting magnet shell in the superconducting magnet;

A deformable seal assembly deformably connected between the mobile joint and the superconducting magnet housing; and

A power control device for providing a driving force for the movement of the moving joint;

Wherein, the power control device includes a power component with an inner cavity, and the inner cavity is filled with an acting medium; the power component acts on the inner cavity according to the acting medium itself or an external force, The moving joint is driven to reciprocate relative to the superconducting magnet housing between a connection position in contact with the fixed joint and a disconnected position separated from the fixed joint.

In one of the embodiments, the power assembly includes a first power member and a second power member arranged up and down along the reciprocating direction of the moving joint, and the inner cavity includes a first inner portion opened in the first power member Cavity, the acting medium includes a first acting medium contained in the first inner cavity;

The first inner cavity has a common wall connected to the second power member, and the movable joint acts on the common wall according to the acting force of the first acting medium and the second power member, The connection position and the disconnection position reciprocate.

In one of the embodiments, the second power part is a deforming member that is deformably connected between the common wall and the outer surface of the superconducting magnet housing along the reciprocating direction of the moving joint.

In one of the embodiments, the inner cavity includes a second inner cavity opened in the second power member, and the acting medium includes a second acting medium contained in the second inner cavity;

The common wall is an elastic wall, and the movable joint is fixedly connected to the common wall, and follows the common force according to the acting force of the first acting medium and the second acting medium acting on the common wall The wall reciprocates between the connected position and the disconnected position.

In one of the embodiments, the first acting medium is directly filled in the first inner cavity, and the pressure remains unchanged, and the second acting medium is directly filled in the second inner cavity, and Variable pressure.

In one of the embodiments, the first inner cavity is provided with a first air bag, and the second inner cavity is provided with a second air bag; the first acting medium and the second acting medium are respectively filled in The gas in the first airbag and the second airbag.

In one of the embodiments, the power control device includes a control assembly, the control assembly includes a pipe and a control switch, a first end of the pipe extends into the second airbag, and a second end of the pipe Atmospheric pressure is connected, and the third end of the pipe is connected to the medium source; the control switch is provided on the pipe to control the connection and disconnection of the pipe with the medium source and the atmosphere.

In one of the embodiments, the moving joint includes a connecting end and an operating end, and the power assembly is assembled on the outer surface of the superconducting magnet housing;

The connecting end extends into the superconducting magnet and detachably contacts the fixed joint, and the operating end passes through the inner cavity in a reciprocating direction.

In one of the embodiments, the deformation seal assembly includes an insulation member and a deformation member, the insulation member is sealed and insulated around the outer periphery of the movable joint, the deformation member is connected to the insulation member and the super Between the hole walls of the assembling hole on the magnet guide shell for the mobile joint to protrude.

A superconducting magnet includes a superconducting coil, a low-temperature cooling unit for providing superconducting temperature for the superconducting coil, and a current lead structure for realizing conduction between the superconducting coil and an external circuit; the low-temperature cooling The unit includes a superconducting magnet housing, a cold screen internal structure and a cold screen, the cold screen is disposed between the superconducting magnet housing and the cold screen internal structure; the current lead structure is the current lead structure described above .

The current lead structure and superconducting magnet provided by this application, the connection or disconnection of the two parts of the fixed joint and the mobile joint are controlled. During excitation and field drop, the mobile joint moves to connect with the fixed joint to conduct the super The conducting coil and the external circuit are similar to the permanent current lead; after the closed loop of the superconducting coil is completed, the moving joint is moved to be disconnected from the fixed joint, similar to the temporary current lead, but at this time the moving joint is still connected to the superconducting magnet housing through the deformation sealing assembly In other words, the current lead structure takes into account both the convenience of permanent current lead operation and the advantage of no additional heat conduction after the temporary current lead is pulled out. At the same time, a power control component is provided in the current lead structure to realize automatic control of the connection of the moving joint and the fixed joint, and the operation is convenient.

BRIEF DESCRIPTION

1 is a schematic diagram of a first implementation manner of a current lead structure of a superconducting magnet in the first example of the present invention;

2 is a schematic diagram of a second implementation manner of the current lead structure of the superconducting magnet in the first embodiment of the present invention;

3 is a schematic diagram of a third implementation manner of the current lead structure of the superconducting magnet in the first embodiment of the present invention;

4 is a schematic diagram of a current lead structure of a superconducting magnet in a second embodiment of the invention;

FIG. 5a is a schematic diagram of the cooperation between the deformation sealing assembly and the moving joint in the embodiment of the superconducting magnet shown in FIG. 1;

5b is a schematic diagram of the cooperation between the deformation sealing assembly and the moving joint in another embodiment of the superconducting magnet shown in FIG. 1;

FIG. 5c is a schematic diagram of the cooperation between the deformation seal assembly and the moving joint in another embodiment of the superconducting magnet shown in FIG. 1. FIG.

detailed description

In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to related drawings. The drawings show preferred embodiments of the invention. However, the present invention can be implemented in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

It should be noted that when an element is said to be "fixed" to another element, it may be directly on the other element or there may be an element between the two. When an element is considered to “connect” another element, it may be directly connected to the other element or may exist between the two elements at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terminology used in the description of the present invention herein is for the purpose of describing specific embodiments, and is not intended to limit the present invention. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

With the development of science and technology, superconducting technology has been more widely used in industry and scientific research. Specifically, superconducting magnets made of superconducting materials can be applied to technical fields such as motors, magnetic levitation transportation, magnetic resonance imaging (Magnetic Resonance Imaging, MRI), nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR), and other technical fields. Among them, represented by medical superconducting magnets, medical superconducting magnets have become an important part of modern high-field MRI systems. Their main role is to provide high-strength and high-stability background magnetic fields for MRI work, which is convenient for achieving fast and high contrast. And high-definition imaging.

The superconducting magnet is mainly composed of superconducting coil, superconducting switch, low temperature unit, auxiliary circuit and current lead. Among them, the superconducting coil generates a magnetic field by passing current, which is the main energy storage component; the superconducting switch ensures that the superconducting coil works steadily in the closed-loop and open-loop state, and the low-temperature unit ensures that all components that need to work in the superconducting state are at superconducting temperature, auxiliary The circuit mainly completes the quench protection of the superconducting magnet and other functions, so that the superconducting magnet will not damage the coil by high voltage or high temperature during the quenching process; the current lead is used to connect the superconducting coil with the external circuit to realize the superconducting coil Excitation and drop field.

Among them, the temporary current lead is only used when operating the superconducting magnet, such as providing a current channel when exciting or dropping the field; when the predetermined operation is completed, the current lead and the superconducting magnet are separated and taken out. When the temporary current lead is connected to the internal connector of the superconducting magnet (due to entering the 4K environment from the 300K environment), there will be inadequate contact at the junction, resulting in the junction resistance greater than the safe value, thereby increasing the superconductivity during excitation and field reduction The risk of magnet quenching; at the same time, a small amount of air will be brought into the process of joining the temporary current lead and the internal connector of the superconducting magnet, especially after many operations, the frost at the junction of the superconducting magnet and the current lead is even worse The icing directly causes the resistance value of the junction between the temporary current lead and the internal connector of the superconducting magnet to increase, thereby increasing the risk of quenching of the superconducting magnet during excitation and field reduction. In addition, frequent manual insertion and removal, the operation is complicated and increases the labor intensity of the operator.

The permanent current lead is kept inside the superconducting magnet no matter during the excitation or field reduction or after any operation is completed. One end is connected to the internal circuit of the superconducting magnet, and the other end is connected to the power cable outside the superconducting magnet. That is, the permanent current lead will always be connected to the internal circuit of the superconducting magnet. When connecting to the external circuit, there is no process from 300K to 4K, which can avoid the adverse factors caused by the temporary current lead and facilitate the excitation and derating of the superconducting magnet at any time. Field operations. The permanent current lead should not only ensure low resistance to avoid excessive heat generation after passing current, but also ensure small thermal conductivity to avoid excessive heat leakage.

In order to solve the above problems of the temporary current leads and the permanent current leads, the present invention provides a semi-permanent current lead structure to solve the above problems.

In order to facilitate understanding, the structure of the superconducting magnet is briefly introduced first. Because of the low-temperature superconducting magnet, it must operate in the low-temperature temperature range of about 4K (-269℃). Therefore, in order to maintain the working environment of the low-temperature superconducting magnet, the low-temperature superconducting magnet is usually designed as a Dewar vessel with high vacuum and high insulation performance.

Among them, the Dewar container includes the internal structure of the cold screen, the superconducting magnet shell and the cold screen. The internal structure of the cold screen is filled with liquid helium and helium, and the superconducting coil in the superconducting magnet is immersed in liquid helium. The superconducting magnet shell is arranged outside the internal structure of the cold screen, and forms a double-walled structure with the internal structure of the cold screen. At the same time, a high vacuum is drawn between the walls to reduce the heat transfer of the gas, and the two opposite surfaces of the double wall are plated or polished to reduce the emissivity, thereby reducing the radiation heat transfer as much as possible. The cold screen (50K environment) is installed between the internal structure of the cold screen and the superconducting magnet shell, and a multi-layer polymer insulation film is wound outside the cold screen to minimize the superconducting magnet shell (the external temperature is 300K) to the cold screen Thermal radiation (ie, heat leakage) of the internal structure (4K environment).

Please refer to FIG. 1 to FIG. 4, the current lead structure of the present invention is assembled on a superconducting magnet, and is used to connect the superconducting coil with an external circuit to generate a magnetic field and realize the energy storage of the superconducting coil. The current lead structure includes a fixed joint (ie, 10a, 10b mentioned below), a movable joint (ie, 30a, 30b mentioned below), a deformation seal assembly 50, and a power control device 70.

Among them, the fixed joint (namely 10a, 10b mentioned below) is fixedly arranged on one of the internal structure of the superconducting magnet cold screen and the cold screen 200, and the movable joint is movably arranged on the superconducting magnet housing 400 of the superconducting magnet , The power control device 70 is used to provide a driving force for the movement of the mobile joint (ie, 30a, 30b mentioned below), so that the mobile joint (ie, 30a, 30b mentioned below) can be driven by the driving force The deformation seal assembly 50 is in a connected position in contact with the fixed joint (i.e. 10a, 10b mentioned below) and a disconnected position separated from the fixed joint (i.e. 10a, 10b mentioned below) relative to the superconducting magnet housing 400 Back and forth.

That is to say, the current lead structure is divided into two parts, one part is fixedly arranged inside the superconducting magnet (ie fixed joint), and the other part is movable through the deformation sealing assembly 50 and the power control device 70 but is always connected to the superconducting magnet (Ie mobile joint). In this way, the mobile joint (ie, 30a, 30b mentioned below) can also be connected to the fixed joint (ie, mentioned below) through the deformation seal assembly 50 and the power control device 70 without being pulled out from the superconducting magnet 10a, 10b) separable contacts, so that the mobile joint (ie 30a, 30b mentioned below) is electrically connected to the fixed joint (ie 10a, 10b mentioned below) when operating the superconducting magnet, such as Excitation or field down; and when the predetermined operation is completed, the mobile joint (ie 30a, 30b mentioned below) and the fixed joint (ie 10a, 10b mentioned below) are separated without pulling from the superconducting magnet Just go out.

The current lead structure in this application takes into account both the convenience of the permanent current lead operation and the advantage of no additional heat conduction after the temporary current lead is pulled out, which is equivalent to a semi-permanent type. The connection or disconnection of the fixed joint (ie 10a, 10b mentioned below) and the mobile joint (ie 30a, 30b mentioned below) is controlled. During excitation and field drop, the mobile joint 30 Move to the fixed joint (namely 10a, 10b mentioned below) to connect (connecting position), turn on the superconducting coil and the external circuit, similar to the permanent current lead; after the closed loop of the superconducting coil is completed, move the joint (ie the next The mentioned 30a, 30b) is moved to the disconnected (disconnected position) from the fixed connector (ie, 10a, 10b mentioned below), similar to the temporary current lead, but at this time the moving connector (ie, 30a mentioned below) 30b) is still connected to the superconducting magnet housing 400 through the deformation sealing assembly 50. At the same time, through the automatic control of the power control device, automatic operation is realized, and the convenience of operation is improved.

Compared with the traditional permanent current lead, the semi-permanent current lead structure in this application will be separated from the fixed joint inside the superconducting magnet after the operation is completed, that is, under the vacuum environment The non-contact state of the current cuts off the heat transmission path of the current lead structure from 300K to 4K to avoid heat leakage. Compared with the traditional temporary current lead, the semi-permanent current lead structure in this application does not need to be manually plugged and unplugged during the operation process (that is, it does not need to enter the 4K environment from the 300K environment each time), so there is no temporary operation while achieving automated operation. The frost phenomenon in the process of plugging and unplugging the current lead also ensures that the contact resistance is lower than the safe value of the design and ensures that the heating is within the controllable range.

In this specific embodiment, the fixed joints (ie, 10a, 10b mentioned below) are provided on the cold screen (50K environment), and the mobile joints (ie, 30a, 30b mentioned below) are provided on the superconducting magnet housing 400 (300K environment), and the two are clutched in the vacuum environment between the superconducting magnet housing 400 (300K component) and the cold screen 200 (50K component), the designed contact area can be much larger than the temporary current lead joints commonly used The contact area effectively guarantees that the contact resistance is lower than the safe resistance value.

Specifically, the mobile joint (namely 30a, 30b mentioned below) includes a connecting end 31 and an operating end 33. The superconducting magnet housing 400 is provided with an assembly hole 401, and the connecting end 31 extends into the superconducting magnet housing 400 through the assembly hole 401 for detachable contact with a fixed joint (namely 10a, 10b mentioned below). The operation terminal 33 is exposed to the outside of the superconducting magnet housing 400 through the assembly hole 401, and is used for the user or an external device to perform force control to drive the connection terminal 31 to contact or separate from the fixed joint (namely 10a, 10b mentioned below) .

The deformation seal assembly 50 includes an insulating member 51 and a deformation member 53. The insulating member 51 is sealed and insulated around the outer periphery of the mobile joint (ie, 30a, 30b mentioned below), and the deformation member 53 is connected to the insulating member 51 and the superconducting magnet housing 400 for the mobile joint (ie, mentioned below) 30a, 30b) between the hole walls of the protruding assembly hole 401, which is used to provide a deformation space for the movement of the moving joint (namely 30a, 30b mentioned below). In this specific embodiment, in order to form a vacuum environment, the insulating member 51 is made of ceramic or resin.

5a-5c, the deformation member 53 includes an elastic film 530 and a supporting portion 532. The elastic film 530 is connected to the outer edge of the insulating member 51. The supporting portion 532 is connected to the elastic film 530 and the mounting hole 401 on the superconducting magnet housing 400 Between the walls of the hole.

Among them, the design, material selection, thickness and size of the deformation member 53 are all related to its own shape. When a force is applied to the moving joint (ie 30a, 30b mentioned below) to connect it with the fixed joint (ie 10a, 10b mentioned below), the deformation member 53 must complete the effective displacement deformation under the force Ensure the effective connection of the mobile joint (ie 30a, 30b mentioned below) and the fixed joint (ie 10a, 10b mentioned below), while ensuring that the deformation of the deformation member 53 is within its safe elastic deformation. The structural displacement response of the deformable member 53 can be obtained by solving the overall stiffness matrix balance equation (1) of the structure through the finite element method.

K·q＝P (1)

Where: K is the overall element stiffness matrix of the structure

q is the overall displacement vector of the structure

P is the overall equivalent external load vector of the structure.

After considering setting the same materials, geometric parameters, applying the same load and boundary conditions to different structures, it is used to optimize based on the results of finite element analysis and find the parameters that meet the application. The following describes three deforming members 53 with different structures as examples, but the shape and structure of the deforming member 53 include, but are not limited to, the examples in the above three types, and applications that use similar structures belong to the scope of this invention.

Referring to FIG. 5a, in one embodiment, the deforming member 53 has a generally circular disc structure, and the elastic film 530 and the support portion 532 are located in the same plane when no deformation occurs. Among them, the elastic film 530 is located on the inner periphery of the disc structure and connected to the outer edge of the insulating member 51, and the support portion 532 is connected to the outer periphery of the elastic film 530.

Referring to FIG. 5b, in another embodiment, the deforming member 53 generally has an inverted bowl structure with an opening toward the cold screen, the elastic film 530 is located on the inner periphery of the inverted bowl structure and is connected to the outer edge of the insulating member 51, and the support portion 532 It is connected to the outer periphery of the elastic film 530.

Referring to FIG. 5c, in yet another embodiment, the deforming member 53 generally has a bowl structure with an opening toward the superconducting magnet housing 400, the elastic film 530 is located on the inner periphery of the bowl structure and is connected to the outer edge of the insulating member 51, and the supporting portion 532 is connected to the outer periphery of the elastic film 530.

In the above three embodiments, the insulating member 51 can be a high-current power feed-through element with a welded edge. The elastic film 530 can be connected to the welded edge of the insulating member 51 by means of vacuum sealant, ceramic sealing or welding. At the same time, both the elastic film 530 and the support portion 532 may be integrally or separately arranged with the same material, or may be integrally or separately arranged with two different materials, which is not limited herein. In this specific embodiment, the elastic film 530 is made of a non-magnetic material with deformability, such as aluminum alloy, titanium alloy, or the like. Correspondingly, the support portion 532 may be made of the same material as the elastic film 530, but it may also be made of a material different from the elastic film 530, and even the support portion 532 may be made of a rigid (not deformable) material It is only necessary to realize that the movable joint 30 can move at least under the deformation force of the elastic film 530, which is not limited herein. In addition, in order to facilitate process molding and manufacturing, the deformation member 53 is preferably made of the same material as the superconducting magnet housing 400.

The power control device 70 includes a power assembly having an inner cavity, and the inner cavity is filled with an acting medium. The power assembly drives the mobile joint (namely 30a, 30b mentioned below) to the superconducting magnet housing 400 and the fixed joint (named 10a mentioned below) according to the acting medium or the external force acting on the inner cavity. , 10b) The connection position of the contact, and the disconnection position separated from the fixed joint (namely 10a, 10b mentioned below) reciprocate.

In addition, the end of the operating end 33 away from the connecting end 31 passes through the inner cavity and is exposed outside the inner cavity for the operator to manually control, that is, to realize the automatic and manual dual control of the current lead structure 100.

Since the driving force provided by the power component for the mobile joint (namely 30a, 30b mentioned below) can be generated by the acting medium acting on the inner cavity itself, it can also be generated by the acting medium and the external force acting on the inner cavity together. Therefore, the following two simple examples are given below, but the following embodiments are only used as examples to illustrate, and do not limit the technical scope of the present invention. Furthermore, the drawings in the embodiments also omit unnecessary components to clearly show the technical features of the present invention.

The power assembly includes a first power member 71 and a second power member 73 arranged up and down along the reciprocating direction of the moving joint 30a/30b. The inner cavity includes a first inner cavity 7101a/7101b opened in the first power member 71, and the acting medium includes a housing The first acting medium in the first inner cavity 7101a/7101b. The first inner cavity 7101a/7101b has a common wall 716 connected to the second power member 73, the movable joint 30a/30b is fixedly connected to the common wall 716, and acts on the common wall 716 together with the second power member 73 according to the first acting medium The applied force follows the common wall 716 to and fro between the connected position and the disconnected position.

First embodiment

Please refer to FIGS. 1-3. The inner cavity includes a first inner cavity 7101a formed in the first power member 71 and a second inner cavity 7103a formed in the second power member 73. The acting medium includes the first inner cavity The first acting medium in 7101a and the second acting medium contained in the second inner cavity 7103a. The first inner cavity 7101a and the second inner cavity 7103a are connected to each other and arranged up and down along the reciprocating direction of the moving joint 30a. The two have a common wall 716 which is an elastic wall. The moving joint 30a is fixedly connected to the common wall 716, and reciprocates between the connected position and the disconnected position following the common wall 716 according to the acting force of the first acting medium and the second acting medium acting on the common wall 716. That is to say, the force received by the power assembly is the sum of the force acting on the common wall 716 by the first acting medium in the first inner cavity 7101a and the second acting medium in the second inner cavity 7103a.

The first

Referring to FIG. 1, the power assembly formed by the first power member 71 and the second power member 73 is generally hollow frame-shaped, which includes an upper top wall 712 and formed by extending both ends of the upper top wall 712 in the same direction Two sidewalls 714. The upper top wall 712 is directly opposite to the superconducting magnet housing 400, the ends of the two side walls 714 away from the upper top wall 712 are fixedly connected to the superconducting magnet housing 400, and the common wall 716 is connected between the two side walls 714 for The inner cavity 710 is partitioned to form a first inner cavity 7101a and a second inner cavity 7103a distributed along the reciprocating direction of the moving joint 30a. At this time, the second inner cavity 7103a is jointly defined by the common wall 716, the superconducting magnet housing 400, and the lower halves of the two side walls 714.

When the first inner cavity 7101a is filled with a certain first acting medium, the internal pressure of the first inner cavity 7101a rises, the pressure of the first acting medium acting on the common wall 716 causes the common wall 716 to deform downward, and the power assembly will drive to move The joint 30b moves closer to the fixed joint 10b, and contacts and communicates with the fixed joint 10b (that is, the communication position); and when the internal pressure of the first inner cavity 7101a decreases, the pressure of the first acting medium acting on the common wall 716 becomes smaller The power assembly will drive the movable joint 30a to return under the action of the deformation force of the common wall 716, so that the movable joint 30a is separated from the fixed joint 10b (ie, the disconnected position).

Specifically, the power control device 70 includes a control assembly. The control assembly includes a pipe 75 and a control switch 77. The first end of the pipe 75 extends into the first inner cavity 7101a, and the second end of the pipe 75 communicates with the atmospheric pressure. The three ends are connected to the medium source. The control switch 77 is provided on the pipeline 75 for controlling the connection and disconnection of the pipeline 75 with the medium source and the atmosphere.

In this specific embodiment, the first acting medium can be directly filled in the first inner cavity 7101a with a variable pressure; the second acting medium is directly filled in the second inner cavity 7103a, and the pressure remains unchanged. Specifically, the first end of the pipe 75 extends into the second inner cavity 7103a, the second end of the pipe 75 communicates with the atmospheric pressure, and the third end of the pipe 75 communicates with the medium source. The control switch 77 is provided on the pipeline 75 for controlling the connection and disconnection of the pipeline 75 with the medium source and the atmosphere.

For example, by operating the control switch 77, the first working medium in the external medium source (such as a nitrogen tank) is charged into the first inner cavity 7101a through the pipeline 75, the pressure in the first inner cavity 7101a increases, and the common wall 716 deforms downward , The moving joint 30 moves with the common wall 716 toward the fixed joint 10a, and contacts and communicates with the fixed joint 10a (ie, the communication position); and when the control switch 77 is operated again, the first inner cavity 7101a communicates with the atmospheric pressure, at this time The pressure in the first inner cavity 7101a decreases, the common wall 716 is reset, and the movable joint 30a is separated from the fixed joint 10b (ie, the disconnected position) with the common wall 716.

Understandably, in some other embodiments, it may also be set as:

Referring to FIG. 2, the power assembly further includes a lower bottom wall 718 connected between the two side walls 714, that is, the power assembly is a frame-like structure that forms the first inner cavity 7101a and the second inner cavity 7103a by itself; meanwhile, the first The inner pressure of the inner cavity 7101a remains unchanged, while the pressure of the second inner cavity 7103a is variable; the first end of the pipe 75 extends into the second inner cavity 7103a, the second end of the pipe 75 communicates with the atmospheric pressure, and the third end of the pipe 75 Communicate with the medium source. The control switch 77 is provided on the pipeline 75 for controlling the connection and disconnection of the pipeline 75 with the medium source and the atmosphere.

For example, the first inner cavity 7101b keeps 5KG of nitrogen unchanged, and the control switch 77 is operated to charge the second inner cavity 7103a with 6KG of nitrogen through the pipeline 75; at this time, the first acting medium acts on the common wall 716 The pressure is less than the pressure of the second acting medium acting on the common wall 716, the common wall 716 deforms upward, the moving joint 30a moves away from the fixed joint 10a, and separates from the fixed joint 10a (ie, the disconnected position); By controlling the switch 77, the second inner chamber 7103a communicates with atmospheric pressure. At this time, the pressure of the first acting medium acting on the common wall 716 in the first inner chamber 7101a is greater than the pressure of the second acting medium acting on the common wall 716. The common wall 716 Deformed downward, the moving joint 30a moves closer to the fixed joint 10a, so that the moving joint 30a is in contact with the fixed joint 10a (ie, the connection position).

Understandably, in some other embodiments, it may also be set as:

Please refer to FIG. 3, the first inner cavity 7101a is provided with a first air bag 7111, and the second inner cavity 7103a is provided with a second air bag 7113; the first acting medium and the second acting medium are respectively filled in the first air bag 7111 and The gas in the second airbag 7113. The first end of the duct 75 extends into the second air bag 7113 in the second inner cavity 7103a, the second end of the duct 75 communicates with atmospheric pressure, and the third end of the duct 75 communicates with the medium source. The control switch 77 is provided on the pipeline 75 for controlling the connection and disconnection of the pipeline 75 with the medium source and the atmosphere.

For example, in the first inner cavity 7101a, the first air bag 7111 keeps 5KG of nitrogen unchanged, and the control switch 77 is operated, and the second air bag 7113 is charged with 6KG of nitrogen through the pipeline 75 using a nitrogen tank; at this time, the first air bag 7111 acts on the public The pressure on the wall 716 is less than the pressure of the second airbag 7113 acting on the common wall 716, the common wall 716 deforms upward, the moving joint 30a moves away from the fixed joint 10b, and separates from the fixed joint 10a (ie, the disconnected position); When the control switch 77 is operated again, the second airbag 7113 communicates with the atmospheric pressure. At this time, the pressure of the first acting medium acting on the common wall 716 in the first airbag 7111 is greater than the pressure of the second acting medium acting on the common wall 716. The wall 716 deforms downward, and the moving joint 30a moves in a direction close to the fixed joint 10a, so that the moving joint 30a and the fixed joint 10a are in contact and communication (ie, the connection position).

Second embodiment

Referring to FIG. 4, the power assembly formed by the first power member 71 is generally hollow frame-shaped, and includes an upper top wall 712 and two side walls 714 formed by extending both ends of the upper top wall 712 in the same direction. The upper top wall 712 is directly opposite to the superconducting magnet housing 400, the ends of the two side walls 714 away from the upper top wall 712 are fixedly connected to the superconducting magnet housing 400, and the common wall 716 is slidably connected up and down along the reciprocating direction of the moving joint 30b Between the two side walls 714, the common wall 716, the upper top wall 712, and the upper halves of the two side walls 714 surround and form a first inner cavity 7101b.

The second power member 73 is a deforming member that is deformably connected between the common wall 716 and the outer surface of the superconducting magnet housing 400 along the reciprocating direction of the moving joint 30b. In other words, the first power member 71 and the deforming member with the first inner cavity 7101b are arranged up and down along the reciprocating direction of the moving joint 30b. When the pressure of the first acting medium acting on the common wall 716 in the first inner cavity 7101b is overcome During the deformation force of the deforming member, the common wall 716 slides down along the side wall 714, and compresses the deforming member, drives the moving joint 30b to move closer to the fixed joint 10b, and contacts and communicates with the fixed joint 10b (ie, the communication position); and When the pressure of the first acting medium acting on the common wall 716 in the first inner cavity 7101b is less than the deforming force of the deforming member, the power assembly will drive the movable joint 30b to be reset under the deformation force of the deforming member, so that the movable joint 30b and the fixed The joint 10b is disconnected (ie, disconnected position).

Specifically, the power control device 70 includes a control assembly including a pipe 75 and a control switch 77. The first end of the pipe 75 extends into the first inner cavity 7101b, the second end of the pipe 75 communicates with the atmospheric pressure, and the first end of the pipe 75 The three ends are connected to the medium source. The control switch 77 is provided on the pipeline 75 for controlling the connection and disconnection of the pipeline 75 with the medium source and the atmosphere.

For example, by operating the control switch 77, the first working medium in the external medium source (such as a nitrogen tank) is filled into the first inner cavity 7101b through the pipe 75, and when the pressure of the first working medium acting on the common wall 716 overcomes the deformation During the deformation of the component, the power assembly will drive the mobile joint 30 to move closer to the fixed joint 10b and make contact with the fixed joint 10b (ie, the communication position); and when the control switch 77 is operated again, the first inner cavity 7101b and the Atmospheric pressure is connected, when the pressure of the first acting medium acting on the common wall 716 in the first inner cavity 7101b is less than the deformation force of the deforming member, the power assembly will drive the mobile joint 30b to return under the deformation force of the deforming member, so that the movement The joint 30b is separated from the fixed joint 10b (ie, disconnected position).

In this specific embodiment, the deforming member is a telescopic spring, and the first acting medium is nitrogen gas filled in the first inner cavity 7101b. Understandably, in some other embodiments, the deforming component may be another element with deforming capability, and the first acting medium may be gas, liquid, or particulate matter, which is not limited herein.

Please refer to FIGS. 1-4. In all the above-mentioned embodiments, a liquid nitrogen chamber for liquid nitrogen is opened inside the movable joint 30a/30b, which is used to cool the movable joint 30a/30b and reduce the current lead structure to be energized. Fever in the process.

Specifically, the liquid nitrogen chamber is configured to extend from the operation end 33 to the connection end 31, so that the entire movable joint 30 is cooled by the input of liquid nitrogen. In this specific embodiment, the liquid nitrogen chamber includes a liquid nitrogen input channel 350, a cooling chamber 352, and a nitrogen output channel 354. The cooling chamber 352 is disposed at the end of the connection end 31 that contacts the fixed joint 10, and the liquid nitrogen input channel 350 and nitrogen output The channels 354 are all connected between the outside and the cooling cavity 352. That is, after the liquid nitrogen input from the liquid nitrogen input channel 350 cools the cavity 352, the mobile joint 30 is cooled and cooled; the heated nitrogen is discharged through the nitrogen output channel 354, so that the liquid nitrogen circulates inside the mobile joint 30 To achieve the effect of cooling and cooling.

The current lead structure provided in this application has the following beneficial effects:

1. The operation is convenient. The semi-permanent current lead structure in this application takes into account the convenience of the permanent current lead. It only needs a simple connection operation when it needs to be connected, and there is no problem of repeated insertion and removal of temporary current leads;

2. Low heat generation during use, the joint of the movable joint 30a/30b and the fixed joint 10a/10b of the semi-permanent current lead structure in this application can reduce the contact resistance and heat by expanding the contact area; at the same time, there is no temporary current lead insertion and extraction The frost phenomenon in the process also effectively reduces the contact resistance and heat generation;

3. By charging liquid nitrogen inside the current lead structure to lower the temperature, the current lead structure is reduced in heating during energization;

4. To reduce the heat conduction during use, after the excitation and field reduction process of the semi-permanent current lead structure in this application is completed, the moving joint 30a/30b and the fixed joint 10a/10b in the current lead structure will be disconnected and cut off inside the superconducting magnet vacuum chamber The heat conduction channel is reduced, reducing the heat conduction from the 300K environment to the 4K environment.

5. Through automatic control, the on-off of the current lead structure is automatically controlled to realize automatic operation.

The superconducting magnet provided in the first embodiment of the present invention has all the technical features of the current lead structure, so it has the same technical effect as the current lead structure.

The above-mentioned examples only express several embodiments of the present invention, and their descriptions are more specific and detailed, but they should not be construed as limiting the patent scope of the present invention. It should be noted that, for a person of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all fall within the protection scope of the present invention. Therefore, the protection scope of the invention patent shall be subject to the appended claims.

Claims (10)

A current lead structure is assembled on a superconducting magnet. The current lead structure includes: A fixed joint fixedly arranged on one of the internal structure of the cold screen of the superconducting magnet and the cold screen; A movable joint arranged on the superconducting magnet shell in the superconducting magnet; A deformable seal assembly deformably connected between the mobile joint and the superconducting magnet housing; and A power control device for providing a driving force for the movement of the moving joint; Wherein, the power control device includes a power component with an inner cavity, and the inner cavity is filled with an acting medium; the power component acts on the inner cavity according to the acting medium itself or an external force, The moving joint is driven to reciprocate relative to the superconducting magnet housing between a connection position in contact with the fixed joint and a disconnected position separated from the fixed joint. The current lead structure according to claim 1, wherein the power assembly includes a first power member and a second power member arranged up and down along the reciprocating direction of the moving joint, and the inner cavity includes a A first inner cavity in a power member, the acting medium includes a first acting medium contained in the first inner cavity; The first inner cavity has a common wall connected with the second power part, the movable joint is fixedly connected with the common wall, and acts together with the second power part on the base according to the first acting medium The force on the common wall reciprocates between the connected position and the disconnected position following the common wall. The current lead structure according to claim 2, wherein the second power member is a deforming member, and the deforming member is slidably connected to the common wall and the superconductor along the reciprocating direction of the moving joint Between the outer surfaces of the magnet housing. The current lead structure according to claim 2, wherein the inner cavity includes a second inner cavity opened in the second power member, and the acting medium includes a second cavity received in the second inner cavity Second acting medium The common wall is an elastic wall, and the movable joint is fixedly connected to the common wall, and follows the common force according to the acting force of the first acting medium and the second acting medium acting on the common wall The wall reciprocates between the connected position and the disconnected position. The current lead structure according to claim 4, wherein the first acting medium is directly filled in the first inner cavity, and the pressure remains unchanged, and the second acting medium is directly filled in the In the second inner cavity, and the pressure can be changed. The current lead structure according to claim 4, wherein a first airbag is provided in the first inner cavity, and a second airbag is provided in the second inner cavity; the first acting medium and the second The acting media are gas filled in the first airbag and the second airbag, respectively. The current lead structure according to claim 6, wherein the power control device includes a control assembly, the control assembly includes a pipe and a control switch, a first end of the pipe extends into the second airbag, The second end of the pipe communicates with atmospheric pressure, and the third end of the pipe communicates with the medium source; the control switch is provided on the pipe to control the connection and disconnection of the pipe with the medium source and the atmosphere. The current lead structure according to claim 1, wherein the moving joint includes a connecting end and an operating end, and the power assembly is assembled on an outer surface of the superconducting magnet housing; The connecting end extends into the superconducting magnet and detachably contacts the fixed joint, and the operating end passes through the inner cavity in a reciprocating direction. The current lead structure according to claim 1, wherein the deformation seal assembly includes an insulation member and a deformation member, the insulation member is sealed and insulated around the outer periphery of the moving joint, and the deformation member is connected to Between the insulating member and the hole wall of the mounting hole on the superconducting magnet housing for the mobile joint to extend. A superconducting magnet, characterized by comprising a superconducting coil, a low-temperature cooling unit for providing superconducting temperature for the superconducting coil, and a current lead structure for realizing conduction between the superconducting coil and an external circuit; The low-temperature cooling unit includes a superconducting magnet housing, an internal structure of a cold screen and a cold screen, the cold screen is disposed between the superconducting magnet housing and the internal structure of the cold screen; the current lead structure is the above claims The current lead structure according to any one of 1-9.

Images